damhead creek 2 environmental statement

Transcription

DAMHEAD CREEK 2
ENVIRONMENTAL STATEMENT
VOLUME 1
JUNE 2009
CONTENTS
Page
LIST OF ABBREVIATIONS
SECTION 1
1
EXECUTIVE SUMMARY
1
1.1
Introduction
3
1.2
The Developer
4
1.3
Need for the Project
4
1.4
The Proposed Development
5
1.5
The Environmental Impact Assessment
7
SECTION 2
9
INTRODUCTION
9
2.1
11
2.2
The existing Damhead Creek CCGT Power Station
13
2.3
Introduction to ScottishPower
14
2.4
Overview of Consenting Process
14
2.5
Damhead Creek 2 Environmental Statement
15
SECTION 3
17
RATIONALE FOR DEVELOPMENT
17
3.1
Background
19
3.2
Current Power Generation Capacity and Electricity Demand
19
3.3
National Grid Guidance for Locating New Power Plant
20
3.4
History of Power Generation in Local Area
21
SECTION 4
23
LEGISLATIVE PLANNING POLICY CONTEXT
23
4.1
Overview
25
4.2
Legislative Context
25
4.3
National Policy
26
4.4
Regional Policy
32
4.5
Kent and Medway Structure Plan
37
4.6
Medway Local Plan
41
Damhead Creek 2 - ES Volume 1
June 2009
SECTION 5
47
DESCRIPTION OF THE DEVELOPMENT
47
5.1
Operation of Damhead Creek 2
49
5.2
Construction of Damhead Creek 2
54
SECTION 6
59
DESCRIPTION OF DEVELOPMENT SITE AND ITS SURROUNDINGS
59
6.1
Development Site Description
61
6.2
Development Site Surroundings
62
6.3
Other Developments with Potential Cumulative Impacts
63
SECTION 7
67
SITE SELECTION AND ALTERNATIVES
67
7.1
Site Selection
69
7.2
Alternatives
69
SECTION 8
77
EIA METHODOLOGY
77
8.1
Overview
79
8.2
Environmental Impact Assessment Project Team
79
8.3
Purpose of the Environmental Impact Assessment
79
8.4
Methodology of the Environmental Impact Assessment
79
8.5
Presentation of the Environmental Impact Assessment
81
SECTION 9
83
STAKEHOLDER CONSULTATIONS AND ADDITIONAL STUDIES
83
9.1
Overview
85
9.2
Scoping of the Project
85
9.3
Residents Information Days
85
9.4
Additional Studies
86
9.5
Future Consultations
89
SECTION 10
91
AIR QUALITY
91
10.1
Summary
93
10.2
Introduction
94
June 2009
10.3
Key Planning Policies
94
10.4
Assessment Methodology and Significance Criteria
94
10.5
Receptors and Baseline Conditions
96
10.6
Potential Impacts
99
10.7
Mitigation Measures and Monitoring Programmes
110
10.8
Assessment of Residual Effects
112
10.9
Assessment of Cumulative Effects
113
SECTION 11
119
NOISE AND VIBRATION
119
11.1
Summary
121
11.2
Introduction
121
11.3
122
11.4
122
11.5
123
11.6
Potential Impacts
126
11.7
Mitigation
130
11.8
132
11.9
132
SECTION 12
135
LANDSCAPE AND VISUAL
135
12.1
Summary
137
12.2
Introduction
137
12.3
137
12.4
National Context
139
12.5
Local Context
140
12.6
141
12.7
Baseline Conditions and Receptors
144
12.8
Potential Impacts
147
12.9
Assessment of Effects
149
12.10
Mitigation
152
12.11
153
12.12
157
June 2009
SECTION 13
159
ECOLOGY
159
13.1
Summary
161
13.2
Introduction
162
13.3
162
13.4
163
13.5
170
13.6
Predicted Changes in Baseline
192
13.7
Potential Impacts
192
13.8
Mitigation
220
13.9
225
13.10
228
SECTION 14
237
WATER QUALITY
237
14.1
Summary
239
14.2
Introduction
239
14.3
240
14.4
241
14.5
241
14.6
Potential Impacts
242
14.7
Mitigating Measures and Monitoring Programmes
245
14.8
247
14.9
247
SECTION 15
249
GEOLOGY, HYDROLOGY AND LAND CONTAMINATION
249
15.1
Summary
251
15.2
Introduction
252
15.3
252
15.4
252
15.5
255
15.6
Potential Impacts
262
15.7
265
15.8
Residual Impacts
267
15.9
Cumulative Impacts
267
June 2009
SECTION 16
269
TRAFFIC AND INFRASTRUCTURE
269
16.1
Summary
271
16.2
Introduction
271
16.3
272
16.4
272
16.5
274
16.6
Potential Impacts
275
16.7
Mitigation
278
16.8
278
16.9
278
SECTION 17
281
CULTURAL HERITAGE
281
17.1
Summary
283
17.2
Introduction
283
17.3
284
17.4
284
17.5
287
17.6
Archaeological Potential of the Damhead Creek 2 Site
297
17.7
Potential Impacts
300
17.8
Mitigation
300
17.9
301
17.10
302
SECTION 18
303
SOCIO-ECONOMICS
303
18.1
Summary
305
18.2
Introduction
305
18.3
305
18.4
306
18.5
306
18.6
Potential Impacts
307
18.7
Mitigation
309
18.8
309
18.9
310
June 2009
SECTION 19
311
DAMHEAD CREEK 2 CARBON CAPTURE READINESS
311
19.1
Overview
313
19.2
Introduction
313
19.3
Carbon Capture Technology and Layout
314
19.4
Transport Corridors and Storage Areas
315
19.5
Assessment Summary
316
19.6
Submission of Further Information
316
SECTION 20
317
SUMMARY OF MITIGATION AND MONITORING
317
20.1
Summary
319
20.2
Air Quality
319
20.3
Noise and Vibration
321
20.4
Landscape and Visual
322
20.5
Ecology
324
20.6
Water Quality
329
20.7
Geology Hydrology and Land Contamination
331
20.8
Traffic and Infrastructure
333
20.9
Cultural Heritage
334
20.10
Socio-Economics
334
____________________________
VOLUME 2
A.
INFORMATION ON VIEWING THE ES
Appendix A
B.
PLANNING POLICIES
Appendix B
C.
SCOPING REQUEST
Appendix C
D.
SCOPING OPINION
Appendix D
E.
STATEMENT OF COMMUNITY INVOLVEMENT / CONSULTATION
Appendix E
F.
BASELINE NOISE REPORT
Appendix F
G.
ECOLOGICAL REPORTS
Appendix G
H.
FLOOD RISK ASSESSMENT
Appendix H
I
GROUND INVESTIGATION REPORT
Appendix I
J.
GAZETTEER OF ARCHAEOLOGICAL INTERESTS
Appendix J
K.
ARCHAEOLOGICAL BACKGROUND
Appendix K
____________________________
June 2009
VOLUME 3
FIGURES
____________________________
June 2009
LIST OF ABBREVIATIONS
ACC
AERMOD
ADMS
AL
ALC
ALLI
AOD
APIS
AQMA
AQMS
AQS
BAP
BAT
BBS
BERR
BGS
BH
BSI
BTO
°C
CC
CCGT
CDM
CEGB
CEMP
CHP
CLEA
CO
CO2
COMAH
COSHH
dB
DC
DCS
DEFRA
DETR
DFO
DfT
DHC I
DLN
DoE
DWS
EA
EAL
EC
EC ETS
EIA
EMMP
EMP
EMS
EPR
ES
ESA
June 2009
air cooled condensers
American Meteorology Society/Environmental Protection Agency
Regulatory Model
air quality software
Advisory Leaflet
Agricultural Land Classification
Areas of Local Landscape Importance
above ordnance datum
Air Pollution Information System
air quality management areas
Air Quality Management System
Air Quality Strategy
Biodiversity Action Plan
Best Available Technique
breeding bird survey
Department for Business, Enterprise and Regulatory Reform
British Geological Survey
borehole
British Standards Institute
British Trust for Ornithology
degree Celsius
carbon capture
combined cycle gas turbine
ConDaM (Regulations) Construction (Design and Management)
Regulations 2007
Central Electricity Generating Board
Construction Environmental Management Plan
combined heat and power
Contaminated Land Exposure Assessment
Carbon Monoxide
Carbon dioxide
Control of Major Accident Hazards
Control of Substances Hazardous to Health
decibels
Direct Current
distributed control system
Department for Environment, Food & Rural Affairs
Department of Environment Transport and the Regions
Distillate Fuel oil
Department for Transport’s
Existing Damhead Creek CCGT Power Station
dry low NOx
Department of the Environment
drinking water standards
Environment Agency
Environmental Assessment Level
European Commission
European Community Emissions Trading Scheme
Environmental Impact Assessment
Ecological Monitoring and Management Plan
environmental management plan
Environmental Management System
Environmental Permitting (England and Wales) Regulations 2007
Environmental Statement
Environmentally Sensitive Area
ETS
EU
EQS
FGD
g/MWh
GOSE
g/s
GSP
GT
GW
ha
HER
HGV
HRSG
HSE
IEEM
IEMA
IFA
IPPC
JNCC
K
Kg/MWh
kJ/kg
km
km2
KMBRC
kV
KWT
L
LAQM
LBAP
LCPD
l
l/sec
LCV
LLCA
LPRIA
m
m/s
m3/h
m3/sec
mg/kg
mg/m3
mg/Nm3
MW
MWe
MWth
NA
NAP
NAQS
NBN
NE
NERC
NETCEN
NGC
NGG
NH3
June 2009
Emissions Trading Scheme
European Union
Environmental quality Standards
flue gas desulphurization
gram per megawatt hour
Government Office for the South East
gram per second
Grid Supply Point
generator transformer
gigawatt
hectare
Kent Historic Environment Record
heavy goods vehicle
heat recovery steam generator
Health and Safety Executive
Institute of Ecology and Environmental Management
Institute of Environmental Management and Assessment
Institute of Field Archaeologists
Integrated Pollution Prevention and Control
Joint Nature Conservancy Council
Kelvin
kilograms per megawatt hour
kilojoules per kilogram
kilometre
square kilometre
Kent & Medway Biological Records Centre
kilovolt
Kent Wildlife Trust
lesser of the height of the building
Local Air Quality Management
Local Biodiversity Action Plan
Large Combustion Plant Directive
litre
litre per second
lower calorific value
Local Landscape Character Area
Late Pre-Roman Iron Age
metre
metres per second
cubic metre per hour
cubic metre per second
milligram per kilogram
milligram per cubic metre
milligram per N cubic metre
megawatt
megawatt electrical
megawatt thermal
not applicable
National Allocation Plan
UK National Air Quality Strategy
National Biodiversity Network
Natural England
Natural Environment and Rural Communities
National Environmental Technology Centre
National Grid Company
National Grid Gas
ammonia
NKWR
Nm3/s
NNR
NMR
NO
NO2
NOx
NSA
NSR
NVZ
NW-SE
OS
PAA
PAH
PCA
PCB
PFA
pH
ppb
PPC
PPE
PPG
ppm
PO4
PPS
PM10
RAF
RNAS
RSPB
SAC
SCR
SEERA
SLA
SNCI
SO2
SO4
SPA
SPZ
SSSI
SYS
t/a
t/day
t/h
TPH
g/m 3
UNECE
UK
UKBAP
US
USA
VER
WCA
WEBS
WFD
WHO
ZVI
£/kW
June 2009
North Kent White Slipped Ware
normal meter cubed per second
National Nature Reserves
National Monuments Record
nitric oxide
nitrogen dioxide
oxides of nitrogen
Nitrate Sensitive Areas
noise sensitive receptors
Nitrate Vulnerable Zones
North West to South East
ordnance survey
Penny Anderson Associates Ltd
Polycyclic Aromatic Hydrocarbons
Pre-Construct Archaeology
polychlorinated biphenyl
pulverized fuel ash
Power of hydrogen
parts per billion
Pollution Prevention and Control
personal protection equipment
Planning Policy Guidance
parts per million
phosphate
Planning Policy Statement
particulate matter of up to 10 micron in size
Royal Air force
Royal Naval Air Service
Royal Society for the Protection of Birds
Special Area of Conservation
selective catalytic reduction
South East England Regional Assembly
Special Landscape Area
Site of Nature Conservation Interest
sulphur dioxide
sulphate
Special Protection Area
Source Protection Zone
Site of Special Scientific Interest
Seven Year Statement
tonnes per annum
tonnes per day
tonnes per hour
total petroleum hydrocarbons
microgram per cubic metre
United Nations Economic Commission for Europe
United Kingdom
The UK Biodiversity Action Plan
United States
Updating and Screening Assessment
valued ecological receptor
Wetland Creation Area
Wetland Bird Survey
Water Framework Directive
World Health Organization
Zone of Visual Influence
£ per kilowatt
June 2009
SECTION 1
EXECUTIVE SUMMARY
SECTION 1
EXECUTIVE SUMMARY
1
EXECUTIVE SUMMARY
1.1
Introduction
1.1.1
ScottishPower (DCL) Limited (ScottishPower) proposes to construct and operate a
Combined Cycle Gas Turbine (CCGT) Power Station (Damhead Creek 2 or ‘the
Development’). Damhead Creek 2 will constitute Phase 2 of the Damhead Creek
Power Generation Development, Phase 1 of which is already in existence. Phase 1
comprises the existing Damhead Creek CCGT Power Station on the Hoo Peninsula,
Kent. Damhead Creek 2 will be located on land immediately adjacent to the existing
Damhead Creek CCGT Power Station which was commissioned in 2001.
1.1.2
This Environmental Statement (ES) has been prepared in support of an application for
Section 36 Consent under the Electricity Act 1989 to the Department of Energy and
Climate Change (DECC) to construct and operate an electricity generating station
greater than 50 megawatt electrical (MWe) output. The ES has been prepared by
Parsons Brinckerhoff Limited (PB) on behalf of ScottishPower and details the results
of a comprehensive and independent study of the likely significant environmental
impacts of Damhead Creek 2 and the mitigation measures designed to minimise the
significant adverse environmental impacts of the Development.
1.1.3
Section 90 of the Town and Country Planning Act 1990 provides that on granting any
consent under Section 36 of the Electricity Act 1989, the Secretary of State may direct
that planning permission for the development shall be deemed to be granted. As a
new Section 36 Application is required for Damhead Creek 2, it is not therefore
necessary to apply for a separate planning permission from Medway Council.
However the relevant planning authority, in this case Medway Council, is a statutory
consultee to DECC during the consenting process and has been consulted during the
preparation of this ES.
1.1.4
Should members of the general public wish to make a representation regarding the
Section 36 application then these should be forwarded to either Medway Council
Planning Department or the Electricity Supply Consents team at DECC. Addresses
for these groups are as follows:
For the Attention of: The Chief Executive
Medway Council
Development Control
Gun Wharf
Dock Road
Chatham
Kent ME4 4TR
For the Attention of: Mr Gary Mohammed
Electricity Supply Consents
Department of Energy and Climate Change
1 Victoria Street
London
SW1H OET
1.1.5
Copies of the Section 36 Application with a plan showing the land to which it relates,
ES explaining ScottishPower’s proposals in more detail and presenting an analysis of
the environmental implications of Damhead Creek 2 and Non-Technical Summary
(NTS) of the ES may be inspected during normal office hours at the following
addresses:
Hoo St. Werburgh Library, Church Street, Hoo St. Werburgh, Medway, Kent,
ME3 9AL;
Medway Council, Gun Wharf, Dock Road, Chatham, Kent, ME4 4TR; and,
June 2009
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EXECUTIVE SUMMARY
Damhead Creek Power Station, Kingsnorth, Medway, Kent, ME3 9NZ.
1.1.6
Copies of this ES and the accompanying NTS can be bought for a fee of £75 by
writing to:
James Gallacher
ScottishPower
Commercial Development
Cathcart Business Park
Spean Street
Glasgow
G44 4BE
or
Richard Wearmouth
Parsons Brinckerhoff Limited
Amber Court
William Armstrong Drive
Newcastle Business Park
Newcastle-Upon-Tyne
NE4 7YQ
Cheques should be made payable to Parsons Brinckerhoff Limited.
This information is summarised in Volume 2, Appendix A.
1.2
The Developer
1.2.1
ScottishPower is an international energy company employing around 10 000 staff
world-wide, and through its business of electrical generation, transmission and
distribution services, provides electricity to in excess of 5.2 million homes and
businesses across the UK.
1.2.2
Through the acquisition of ScottishPower in April 2007 by Iberdrola, the combined
Group has become the fourth largest electricity company in the world, generating over
40 000 MW of electricity and supplying almost 22 million customers world-wide.
1.2.3
Within the UK, ScottishPower owns and operates a range of electricity generating
plant, which includes: gas fired power stations; coal fired power stations; hydroelectric pumped storage stations; and, wind farms. ScottishPower is an expert in the
operation of gas fired power stations, with its UK generation portfolio including around
2000 MW of CCGT plant, and Iberdrola’s world-wide generation portfolio includes a
further 10 000 MW of CCGT plant.
1.2.4
The existing Damhead Creek CCGT Power Station is owned and operated by
ScottishPower, and has been successfully operating since it was commissioned in
2001.
1.3
Need for the Project
1.3.1
The bulk of power generation in the UK today is located in northern areas of England
and Scotland, either in the vicinity of UK coal fields or on the coast where fuel
supplies can be readily imported. This situation is much the same for many
renewable forms of generation including wind farms and hydroelectric plant that are
generally situated in more remote locations where the resources they require are
more abundant. The main electricity demand in the UK however is in the south of
England, particularly in London, the south east, the south west and some parts of the
Midlands where demand is increasing.
1.3.2
The current situation, therefore, requires power to be transported to these areas of
high demand via transmission lines belonging to the National Grid. As demand
June 2009
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EXECUTIVE SUMMARY
increases, more transmission lines are required as the need to reinforce the electricity
transmission system arises. An alternative to system reinforcement is to generate
more electricity in the areas where it is needed. This not only helps negate the need
for long power lines but also gives the added environmental benefit of reducing
electrical transmission losses.
1.3.3
The UK currently has a generating capacity of around 75 GW based on various
technologies, the most significant contributions being from coal fired power stations.
The Large Combustion Plant Directive (Directive 2001/80/EC) (LCPD) requires power
stations to adhere to stringent air quality standards. Several coal and oil plants
throughout the UK, totalling approximately 12 GW, have opted out of this obligation
and, as such, are required to close by the end of 2015 or after 20 000 hours of
operation after 1 January 2008, whichever is sooner.
1.3.4
In addition, according to current timetables, around 7.4 GW of generating capacity will
also be lost by 2020 due to the planned closure of some nuclear generation facilities.
1.3.5
The development of Damhead Creek 2 is intended to help bolster the generating
capacity available to the UK National Grid whilst also seeing the development of a
power station close to London, a centre of high demand.
1.4
1.4.1
The Damhead Creek 2 site lies approximately 3 km south-east of the A228, which
connects the A2/M2 with the Isle of Grain, and 9 km north-east of the city of
Rochester. It is situated on the southern edge of the tongue of land between the
Thames and Medway estuaries known as the Hoo Peninsula. The village of Hoo
St Werburgh, the nearest settlement, lies 3 km to the west between the coast and
A228.
1.4.2
Figure 1.1 shows the location of Damhead Creek 2, which lies immediately to the east
of the existing Damhead Creek CCGT Power Station.
1.4.3
The proposed Development will involve the construction of an additional CCGT Power
Station, which will provide up to 1000 MW of power generation capacity at site rated
conditions and will burn natural gas only. The electricity generated by Damhead
Creek 2 will be delivered to the National Grid.
1.4.4
In addition to power generation, there is the potential for Damhead Creek 2 to supply
heat and / or power to facilities and / or customers in the vicinity of the Damhead
Creek 2 site. This is subject to customers being available, and any proposed scheme
being technically and commercially viable. At present, the most likely identified user
of any heat and / or power would be the Kingsnorth Business Park proposed on land
to the east of the Damhead Creek 2 site by Goodman Developments Limited.
However, other opportunities are also being pursued in this regard.
1.4.5
To the north and west of the Damhead Creek 2 site lies the existing Kingsnorth
Industrial Estate and to the south is the existing Kingsnorth Power Station owned and
operated by E.ON (Kingsnorth Units 1 – 4). Land to the north east of the Damhead
Creek 2 site is filled with pulverised fuel ash and is designated as a future
development area under the Medway Local Plan and emerging Local Development
Framework. Much of this land is now encompassed by two outline planning
applications to Medway Council for a business distribution and storage facility
proposed by Goodman Developments Limited that will include up to eight storage
warehouses and associated infrastructure (Kingsnorth Business Park).
1.4.6
The land for Damhead Creek 2 lies mainly to the east of the existing Damhead Creek
CCGT Power Station site and consists of approximately 6.2 hectares (ha) of land. In
addition, a 400 kV electrical substation will be located on land lying to the north west
of the existing Damhead Creek CCGT Power Station and a second area of land to the
east of the Damhead Creek 2 site will be occupied temporarily during construction for
June 2009
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SECTION 1
EXECUTIVE SUMMARY
car parking and the storage of materials and / or equipment. Following construction
of the Development, the area to the east will be reserved for the installation of Carbon
Capture and Storage (CCS) equipment as per the requirements of DECC.
1.4.7
Damhead Creek 2 will be connected directly into the new 400 kV substation from
where the electrical energy can be exported via the National Grid transmission
network.
1.4.8
The Damhead Creek 2 site adjoins an extensive area of ecological mitigation land
(some 26 ha), which has been established and maintained as part of the existing
Damhead Creek CCGT Power Station development. This mitigation land is owned by
ScottishPower and is managed to mitigate the power generation equipment and
infrastructure within the existing Damhead Creek CCGT Power Station and the site of
Damhead Creek 2.
This mitigation land borders much of the Goodman
Developments Limited site discussed above.
1.4.9
The advantages of the Damhead Creek 2 site for power generation include the
presence of the existing gas main to the existing Damhead Creek CCGT Power
Station. This gas supply pipeline is sized to allow for the expansion of the CCGT
Power Station to accommodate Damhead Creek 2. There will therefore be no
requirement for a new gas pipeline to be constructed to the Damhead Creek 2 site,
although a gas receiving facility will be built on the Damhead Creek 2 site.
1.4.10
In addition there are various facilities on the existing Damhead Creek CCGT Power
Station site which can be utilised for the purposes of Damhead Creek 2. These
include: administration buildings; workshop; stores; water treatment plant; auxiliary
boiler; and, fire fighting services.
1.4.11
Damhead Creek 2 will generate in ‘combined cycle’ mode with an overall electrical
generation efficiency of approximately 55 per cent based on a conservative estimate
of the lower calorific value (LCV) of the fuel. If it becomes technically and
economically feasible to provide heat and / or power to surrounding facilities /
customers, additional fuel utilisation gains may be achieved.
1.4.12
Two gas turbines will be used within Damhead Creek 2, each equipped with proven
pollution control technology, which will limit the production of the oxides of nitrogen
(NOx) to a maximum of 50 mg/Nm3 (at reference conditions) as required by the Large
Combustion Plant Directive (LCPD). The gas turbine technology will be used in
conjunction with steam turbine equipment to provide high efficiency combined cycle
gas turbine operation.
1.4.13
The technology for controlling NOX emissions on gas turbine plant is known as the
Dry Low NO x (DLN). This technique will be used to control emissions of NOx from
Damhead Creek 2 to the atmosphere. The technique represents the Best Available
Technique (BAT) for limiting emissions of NOx to the atmosphere from gas turbine
based power stations. Natural gas is a clean fuel and does not produce the
particulate emissions associated with burning coal; consequently flue gas cleaning
equipment is not required as all atmospheric emissions from the plant will be
controlled at source.
1.4.14
The flue gases from each of the two gas turbine units will be discharged to a
dedicated 75 m high stack. Therefore two new stacks will be constructed. There will
be no bypass stacks installed to permit power generation in the event of the steam
turbine plant being unavailable.
1.4.15
The connection offer from National Grid Company (NGC) is such that Damhead
Creek 2 could enter operation in two phases, the first 500 MW in 2019 and the
second in 2022. This would mean that construction of Damhead Creek 2 would also
occur over two phases with the first starting in 2016 and the second in 2019.
However, there is the possibility of the connection offer being amended by NGC to
allow for connection of Damhead Creek 2 in one stage 2016 depending on a variety
June 2009
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EXECUTIVE SUMMARY
of factors including the construction schedule of various other UK power projects. If
this scenario were to happen, construction of Damhead Creek 2 would likely
commence in 2013.
1.4.16
Should Damhead Creek 2 be built in one stage, construction would take between 28
and 36 months and the construction workforce would peak at around 1000 personnel.
Should a two stage construction phase be pursued this would lengthen the
construction period by around three years, but reduce the construction workforce to a
peak of around 600 personnel and would also reduce the traffic flows associated with
the project.
1.4.17
For the purposes of this ES, both possible construction programmes are considered.
1.4.18
Damhead Creek 2 will operate throughout the year and will be designed to have an
expected operational life of 35 years. The total capital investment in the project by
ScottishPower will be around £600 million. The operation and maintenance costs will
be of the order of £27 million per annum.
1.5
The Environmental Impact Assessment
1.5.1
As discussed above, this ES has been prepared to document the findings of the EIA
which has been undertaken to determine the potential extent of any likely significant
environmental impacts (both positive and negative) with regard to the development of
Damhead Creek 2. The potential receptors of any environmental impacts with regard
to Damhead Creek 2 which have been considered in this ES are:
Air Quality;
Noise;
Landscape and Visual;
Ecology;
Water Quality;
Geology, Hydrology and Land Contamination;
Traffic and Infrastructure;
Socio-Economics; and
Cultural Heritage.
In addition, assessment of the potential for cumulative impacts due to the
development of Damhead Creek 2 and other projects in the area (namely Kingsnorth
Power Station Units 5 and 6 proposed by E.ON, and Kingsnorth Business Park
proposed by Goodman Developments Limited).
1.5.2
In accordance with the Electricity Works (Environmental Impact Assessment)
(England and Wales) Regulations 2000, the ES has gone on to identify measures
envisaged to avoid, reduce and, if possible, remedy any significant adverse impacts
identified.
1.5.3
For impacts that cannot be entirely remedied, the ES identifies the residual effects
once the mitigation is considered. Monitoring has been recommended in some cases
to help demonstrate that the project is operating in compliance with the performance
criteria identified in this ES.
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INTRODUCTION
SECTION 2
INTRODUCTION
2
INTRODUCTION
2.1
2.1.1
ScottishPower (DCL) Limited (ScottishPower) proposes to construct and operate a
Combined Cycle Gas Turbine (CCGT) Power Station (Damhead Creek 2 or ‘the
Development’). Damhead Creek 2 will constitute Phase 2 of the Damhead Creek
Power Generation Development, Phase 1 of which is already in existence and
comprises the existing Damhead Creek CCGT Power Station on the Hoo Peninsula,
Kent. Damhead Creek 2 will be located on land immediately adjacent to the existing
Damhead Creek CCGT Power Station that was commissioned in 2001.
2.1.2
Damhead Creek 2 will provide up to 1000 MW of power generation capacity at site
rated conditions and will burn natural gas only.
2.1.3
In addition to power generation, there is the potential for Damhead Creek 2 to supply
heat and / or power to facilities and / or customers in the vicinity of the Damhead
Creek 2 site. This is subject to customers being available, and any proposed scheme
being technically and commercially viable. At present, the most likely identified user
of any heat and / or power would be the Kingsnorth Business Park proposed on land
to the east of the Damhead Creek 2 site by Goodman Developments Limited.
However, other opportunities are also being pursued in this regard. Further details on
this potential are provided in Section 9.
2.1.4
The Damhead Creek 2 site is located on land immediately adjacent to the existing
Damhead Creek CCGT Power Station that was commissioned in 2001. The site
location is shown in Figure 1.1.
2.1.5
The site lies approximately 3 km south-east of the A228, which connects the A2/M2
with the Isle of Grain, and 9 km north-east of the city of Rochester. It is situated on
the southern edge of the tongue of land between the Thames and Medway estuaries
known as the Hoo Peninsula. The village of Hoo St Werburgh, the nearest
settlement, lies 3 km to the west between the coast and A228.
2.1.6
Creek 2 site is filled with pulverised fuel ash and is designated as a future
development area under the Medway Local Plan. Much of this land is now
encompassed by two outline planning applications to Medway Council for a business
distribution and storage facility proposed by Goodman Developments Limited which
will include up to eight storage warehouses and associated infrastructure (Kingsnorth
Business Park).
2.1.7
The Damhead Creek 2 site is divided into three main areas, which are shown on
Figure 2.1. These areas comprise:
Area 1.
6.2 hectares (ha) of land lying mainly to the east of the existing Damhead
Creek CCGT Power Station. This is the location of Damhead Creek 2 and
is shown shaded red on Figure 2.1;
Area 2.
3.6 ha of land lying to the north west of the existing Damhead Creek CCGT
Power Station. This is the location of the proposed 400 kV substation and is
shown shaded green on Figure 2.1; and,
Area 3.
14 ha of land lying to the north-east of the existing Damhead Creek CCGT
Power Station. Approximately 7.5 ha of this area will be used temporarily
for car parking and the storage of materials and equipment during the
construction phase of the Development. It is intended that this area will also
be set aside for the installation of Carbon Capture and Storage (CCS)
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INTRODUCTION
equipment in the future, and thus will be reserved as such. The remainder
of the area would be dedicated to ecological mitigation including additional
ponds and habitat enhancement. All land in this area has previously been
used to dispose of the fly ash from the nearby Kingsnorth Power Station. It
is surrounded by ecological mitigation land associated with the development
of the Damhead Creek Power Generation Development, and currently
contains a number of small ponds. This area is shaded blue on Figure 2.1.
2.1.8
(some 26 ha) which is also shown on Figure 2.1 as the light yellow area. This area
has been established and maintained as part of the Damhead Creek Power
Generation Development. This mitigation land borders the land that is the subject of
the two outline planning applications submitted by Goodman Developments Limited
as discussed above.
2.1.9
This mitigation land is owned by ScottishPower and is managed to mitigate the power
generation equipment and infrastructure within the Damhead Creek Power
Generation Development. During tenure as owner of the existing Damhead Creek
CCGT Power Station, ScottishPower have been proactive in the environmental
management of the CCGT Power Station and the associated mitigation land for which
a Biodiversity Action Plan has been developed. The ecological management of this
land has seen the reintroduction of species including Barn Owls and Marsh Harriers,
which is a significant achievement and a major boost to biodiversity in the area.
2.1.10
This mitigation area was created subject to a Nature Conservation Management Plan
in 1998 that established a series of development and maintenance works over a five
year period, which included botanical survey, translocation of important habitats,
habitat creation, and subsequent monitoring. The mitigation land comprises the
following areas; wetland creation area (previously mentioned and discussed), coastal
corridor, north east exclusion area, north west exclusion area and the western
corridor. In combination these areas effectively surround Area 3 of the Development
site. Habitats present within the mitigation land include; open water, scrapes, reed
swamp, marsh, saltmarsh, ruderal grassland, bare ground wood and scrub, coastal
grassland.
2.1.11
The advantages of the Damhead Creek 2 site for power generation include the
presence of the existing gas main to the existing Damhead Creek CCGT Power
Station, which is sized to provide an adequate supply of fuel to Damhead Creek 2. In
addition, there are various facilities at the existing Damhead Creek CCGT Power
Station, such as administration buildings, workshop, stores, water treatment plant,
auxiliary boiler and fire fighting services, which have sufficient capacity to be utilised
for Damhead Creek 2.
2.1.12
Damhead Creek 2 will be connected directly into a new 400 kV substation that will be
located within The Damhead Creek 2 site on the land shaded green on Figure 2.1,
from where the electrical energy can be exported via the National Grid transmission
network. Damhead Creek 2 is not expected to require an overhead transmission line
to connect to the National Grid, although the final design of the connection will be the
subject of a separate study / Section 37 application by National Grid Company (NGC).
2.1.13
As stated above, the existing gas supply pipeline for the existing Damhead Creek
CCGT Power Station is sized to allow for the expansion of the power station to
accommodate Damhead Creek 2. There will therefore be no requirement for a new
gas pipeline to be constructed to the Damhead Creek 2 site, although a gas receiving
facility will be built on the Damhead Creek 2 site.
2.1.14
Damhead Creek 2 will generate in ‘combined cycle’ mode with an overall electrical
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INTRODUCTION
2.1.15
Two gas turbines will be used within Damhead Creek 2, each equipped with proven
pollution control technology, which will limit the production of the oxides of nitrogen
(NOx) to a maximum of 50 mg/Nm3 (at reference conditions). The emissions of NO x
will therefore be in accordance with the limits set in the Large Combustion Plant
Directive (LCPD) of 50 mg/Nm 3. The gas turbine technology will be used in
conjunction with steam turbine equipment to provide high efficiency combined cycle
gas turbine operation.
2.1.16
The technology for gas firing, known as the Dry Low NO x (DLN) system, limits
emissions of NOx to atmosphere. This technique represents the Best Available
Technique (BAT) for limiting emissions of NOx to atmosphere from gas turbine based
power stations. Natural gas is a clean fuel and does not produce the particulate
emissions associated with burning coal; consequently flue gas cleaning equipment is
not required as all atmospheric emissions from the plant will be controlled at source.
2.1.17
The flue gases from each of the two gas turbine units will be discharged to a
dedicated 75 m high stack. Therefore two new stacks will be constructed. There will
be no bypass stacks installed to permit power generation in the event of the steam
turbine plant being unavailable.
2.1.18
The total capital investment in the project by ScottishPower will be around
£600 million. The operation and maintenance costs will be of the order of £27 million
per annum.
2.1.19
occur over two phases with the first starting in 2016 and the second in 2019. There is
however the possibility of the connection offer being amended by NGC to allow for
connection of Damhead Creek 2 in one stage in approximately 2016 depending on a
variety of factors including the construction schedule of various other UK power
projects. If this scenario were to happen, construction of Damhead Creek 2 would
commence in 2013.
2.1.20
Should Damhead Creek 2 be built in one stage, where the construction would take
between 28 and 36 months the construction workforce would peak at around 1000
personnel. Should a two stage construction phase be pursued this would lengthen
the construction period by around three years, but reduce the construction workforce
to a peak of around 600 and would also reduce the traffic flows associated with the
project.
2.1.21
For the purposes of this ES, both possible construction programmes are considered.
2.1.22
Damhead Creek 2 will operate throughout the year and will be designed to have an
expected operational life of 35 years.
2.2
The existing Damhead Creek CCGT Power Station
2.2.1
The existing Damhead Creek CCGT Power Station was commissioned in 2001 and
consists of two Mitsubishi 701 F3 gas turbines and one associated steam turbine
capable of generating 792 MWe at site rated conditions. ScottishPower purchased
the Power Station from Entergy in 2004. The site of the existing Power Station is
shown edged in blue on Figure 2.1.
2.2.2
The existing Damhead Creek CCGT Power Station is accredited under the
International Standard ISO 14001 and operates in full compliance with the Section 36
Consent conditions and the planning conditions imposed by the Department of Trade
and Industry (DTI) (now DECC) and the requirements of the Station's Pollution
June 2009
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INTRODUCTION
Prevention and Control (PPC) Permit issued by the Environment Agency (EA). The
existing CCGT Power Station also operates an Environmental Management System
(EMS) that helps to ensure a high level of environmental performance is maintained
by the Power Station.
2.2.3
The existing Damhead Creek CCGT Power Station is air cooled and, thus has
extremely low water discharges in comparison to similar sized coal and oil fired
plants. This makes the existing Damhead Creek CCGT Power Station one of the
most efficient of its kind in Europe.
2.3
Introduction to ScottishPower
2.3.1
ScottishPower is an international energy company employing around 10 000 staff
world-wide, and through its business of electrical generation, transmission and
distribution services, provides electricity to in excess of 5.2 million homes and
businesses across the UK.
2.3.2
Through the acquisition of ScottishPower in April 2007 by Iberdrola, the combined
Group has become the fourth largest electricity company in the world, generating over
40 000 MW of electricity and supplying almost 22 million customers world-wide.
2.3.3
Within the UK, ScottishPower owns and operates a range of electricity generating
plant, which includes gas fired power stations; coal fired power stations; hydro-electric
pumped storage stations and wind farms. ScottishPower is expert in the operation of
gas fired power stations, with its UK generation portfolio including around 2000 MW of
CCGT plant, and Iberdrola’s world-wide generation portfolio including a further 10 000
MW of CCGT plant.
2.4
Overview of Consenting Process
2.4.1
Section 36 of the Electricity Act 1989 requires that those seeking to construct, extend
or operate an electricity generating station of over 50 MWe output located within
England and Wales must apply to the Secretary of State for consent. Section 90 of
the Town and Country Planning Act 1990 provides that on granting any consent under
Section 36 of the Electricity Act 1989, the Secretary of State may direct that planning
permission for the development shall be deemed to be granted.
2.4.2
As Damhead Creek 2 will have an output of 1000 MWe, Damhead Creek 2 falls within
the requirements of Section 36 of the Electricity Act 1989 and accordingly
ScottishPower has submitted an application to the Secretary of State for a Section 36
Consent and deemed planning permission. The Section 36 Consent application
procedures are comprehensive, and bring the views of the local planning authority,
local people, consultative bodies (such as the EA, Natural England, Royal Society for
the Protection of Birds (RSPB) and other interested parties) into the decision making
process.
2.4.3
Damhead Creek 2 will be a "regulated facility" under the Environmental Permitting
Regulations (EPR). A regulated facility includes an installation that carries out any of
the activities listed in Schedule 1 to the EPR and any activities that are technically
linked. The activities carried out at Damhead Creek 2 will fall within Schedule 1
Part 2 Chapter 1 Section 1.1 Part A (1) of the EPR (burning any fuel in an appliance
with a rated thermal input of 50 or more megawatts). The EPR provides that no
person may operate a regulated facility except under and to the extent authorised by
an environmental permit and therefore, an application will need to be submitted to the
Environment Agency for a "bespoke" environmental permit.
2.4.4
Only a person who is in control of the facility may obtain or hold an environmental
permit. This is the "operator". The "operator" is defined as the person who has
control over the operation of a regulated facility and must demonstrably have the
authority and ability to ensure that the environmental permit is complied with.
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INTRODUCTION
2.4.5
The regulator, being the Environment Agency for a Part A (1) installation,
recommends that the operator should make an application for an Environmental
Permit in parallel with the planning permission (in this case the Section 36 Consent)
wherever possible. Operators should normally make an application when they have
drawn up full designs but before construction work commences. Although there is
nothing in the EPR to stop an operator from beginning construction before an
environmental permit has been issued, in order to avoid expensive delays, it is in the
operator's interest to submit the application for the environmental permit at the design
stages. The time period for determining an application for a bespoke permit is four
months from the date the regulator receives an application that is subsequently
determined to be "duly made". It is always open to the regulator and the applicant to
agree a longer time period if necessary.
2.4.6
The regulator has a duty to consider the representations made during the
determination process and within the allowed time periods. These representations
may be received from members of the public or interested bodies and persons with
rights to land.
2.4.7
The application for an environmental permit must include an assessment of the
environmental risk of the proposal including the risk under both normal and abnormal
operating conditions. Guidance on environmental risk assessment has been
produced and the regulators should make reference to this guidance (Department of
the Environment, Transport & The Regions, Environment Agency & The Institute For
Environment & Health (2000) Guidelines for Environmental Risk Assessment and
Management – Revised Departmental Guidance).
2.5
Damhead Creek 2 Environmental Statement
2.5.1
The Electricity Works (Environmental Impact Assessment) (England and Wales)
Regulations 2000 (as amended) (the EIA Regulations) apply to Section 36 Consent
applications and require an EIA to be undertaken where the development of a thermal
power station with a heat input of 300 MWth, or more, is proposed. Damhead
Creek 2 exceeds this threshold with a thermal input of the order of 1818 MWth, and
therefore an EIA is required.
2.5.2
During the EIA process, ScottishPower sought a formal ‘Scoping Opinion’ from the
Secretary of State pursuant to Regulation 7 of the EIA Regulations, requesting an
opinion on the information to be expected within the ES. This process allowed
ScottishPower to be clear about what the Secretary of State (and, through
consultation carried out on the Scoping Opinion, stakeholders) considers to be the
likely significant environmental effects of Damhead Creek 2 and therefore the topics
on which the ES should focus. ScottishPower sees communication with a wide range
of stakeholders as a vital part of the pre-submission process so that all concerns are
considered in the EIA process.
2.5.3
Accordingly, this ES has been prepared for submission alongside the application for
Section 36 Consent. The ES has been prepared by PB on behalf of ScottishPower
and details the results of a comprehensive and independent study of the likely
significant environmental impacts of Damhead Creek 2 and the mitigation measures
designed to minimise the significant adverse environmental effects of the proposed
development pursuant to the Electricity Works (Environmental Impact Assessment)
(England and Wales) Regulations 2000 (as amended).
2.5.4
The ES addresses the likely significant environmental effects of Damhead Creek 2
covering both positive and negative impacts during the construction and operational
periods of Damhead Creek 2. The ES enables the reader to understand the nature of
Damhead Creek 2 and to evaluate the likely significant environmental effects, and
therefore acts to aid the decision making process and to present information in a
readily accessible form.
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INTRODUCTION
2.5.5
The ES for Damhead Creek 2 comprises three separate volumes:
Volume 1:
Main Text;
Volume 2:
Appendices; and
Volume 3:
Figures.
2.5.6
A Non-Technical Summary (NTS) is also provided. The NTS outlines the key findings
of the ES.
2.5.7
Within each impact assessment Section included in Volume 1 of the ES (main text),
the existing environment has been described (the baseline conditions), the potential
impacts of the construction and operation phases have been discussed (the
assessment years) and mitigation measures and monitoring programmes proposed
where appropriate. The assessment years used in this ES are:
Construction Period for Stage 1 of the grid connection offer – 2016
Operation Period for Stage 1 of the grid connection offer – 2019
Construction Period for Stage 2 of the grid connection offer – 2019
Operation Period for Stage 2 of the grid connection offer – 2022
Should the grid connection offer be brought forward, then the likely one stage
connection date would be 2016, resulting in a construction start date of 2013
2.5.8
Where there is any uncertainty in the likely significant environmental effects, the
highest likely effect has been considered to allow final design flexibility. This ensures
that the ES is a comprehensive document, evaluating Damhead Creek 2 alternatives
with the greatest potential impact.
2.5.9
Information on viewing and purchasing copies of the ES and accompanying NTS has
been provided in Section 1, and are also detailed in the NTS.
June 2009
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SECTION 3
SECTION 3
3
3.1
Background
3.1.1
Electricity is essential in a modern society. It powers a huge variety of things, from
computers to lights to kitchen appliances to industrial plant. Therefore a growing
economy, combined with the innovation to develop electronic devices, leads to a
considerable upwards pressure on the UK energy market.
3.1.2
At present, a number of substantial challenges face the UK energy market, including:
The forced retirements of existing nuclear and coal / oil plant for safety and
environmental reasons; and
3.1.3
The ever rising demand for electricity.
These challenges are discussed in this Section, which provides the rationale for the
development of Damhead Creek 2.
3.2
Current Power Generation Capacity and Electricity Demand
3.2.1
Currently, the bulk of power generation in the UK is located in northern areas of
England and Scotland, either in the vicinity of the UK coal fields or on the coast where
fuel supplies can be readily imported. This situation is much the same for many
renewable forms of generation including wind farms and hydroelectric plants that are
generally situated in more remote locations where the resources they require are
more abundant.
3.2.2
However, the main electricity demand in the UK is in the south (particularly London),
the south east, the south west and some parts of the Midlands where demand is
increasing.
3.2.3
The current situation, therefore, requires power to be transported to these areas of
high demand via transmission lines belonging to the National Grid. As demand
increases, the need to reinforce the electricity transmission system arises and more
transmission lines are required.
3.2.4
An alternative to system reinforcement is to generate more electricity in the areas
where it is needed. This not only helps negate the need for long power lines, but also
gives the added environmental benefit of reducing electrical transmission losses
which occurs as the electricity is transported along the transmission lines.
3.2.5
Transmission losses can amount to a significant quantity of electricity, such that a
power station generating 1000 MWe in the north of England / Scotland would provide
less than 940 MWe by the time it reached consumers in the south of England.
3.2.6
The UK currently has a generating capacity of around 75 GW based on various
technologies, the most significant contributions being from coal fired power stations.
3.2.7
However, the Large Combustion Plant Directive ((Directive 2001/80/EC) (LCPD)
requires power stations to adhere to stringent air quality standards. Several plants
throughout the UK, totalling 12 GW, have opted-out of this obligation and, as such,
are required to close by the end of 2015 or after 20 000 hours of operation after
1 January 2008 , whichever is sooner.
3.2.8
The operating regimes of these opted-out plants will become a commercial decision
to be taken by the plant operators. This means that it will be impossible to predict the
timing and impact of the LCPD on the UK generation capacity. However, the Energy
Markets Outlook Report, produced by BERR (now DECC) and OFGEM in October
2007, has forecast that based on historical operating patterns, the allowance of hours
will be reached, by some of the opted-out plants, by early 2012.
June 2009
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SECTION 3
3.2.9
In addition, around 7.4 GW of generating capacity will be lost by 2020 due to the
planned closure of some nuclear generation facilities.
3.2.10
The 2007 ‘White Paper on Energy – Meeting the Energy Challenge’ (published by
BERR, now DECC) officially recognised the need to replace the retiring power
generation capacity in the UK, stating that:
“If we are to maintain levels of electricity generation capacity equivalent to those
available today, then new power stations need to be built in time to replace these
closures and to meet increases in demand. On this basis, around 20 to 25 GW of
new power stations will be needed by 2020”.
3.2.11
An additional challenge is presented via the ever rising demand for electricity.
Estimates from the National Grid Forecasts1 indicate that between approximately
5.0 GW (Base Demand) and 13.1 GW (High Demand) of new generation capacity, in
addition to that required to replace closures, will be required by 2020.
3.2.12
Current generation availability data, published in the Energy Markets Outlook Report,
indicates that the effective generating capacity in the UK is around 17 per cent lower
than the installed capacity. The Report also highlights that the electricity generating
industry will face a significant challenge to ensure the timely delivery of new
generating capacity as the demand for electricity continues to rise.
3.2.13
In order to ensure that supply can meet the demand it is necessary to have sufficient
available generating capacity to match the highest anticipated ‘peak’ demand at all
times. The 2007 ‘White Paper on Energy – Meeting the Energy Challenge’ (published
by BERR, now DECC) highlights the need to maintain the security and reliability of
the energy supply in the UK.
3.2.14
The margin between demand forecasts and the available generation capacity is a
strong indicator of the security of the electricity supply. This has been falling steadily
in recent years, thus indicated that there is a decreasing amount of spare capacity
available in the network.
3.3
National Grid Guidance for Locating New Power Plant
3.3.1
Although the National Grid's Transmission Licence requires the National Grid offer a
connection to anyone who requests a connection, the location of the generation in the
system is important as it has an influence on what work must be undertaken to the
system in order for it to comply with the requirements of the Transmission Licence.
3.3.2
The National Grid provides guidance to the market on locations for new generation
through its charging for use of the system. As part of the market guidance, the
National Grid issues a Seven Year Statement (SYS) that details the areas in which
the company would welcome additional generating capacity.
3.3.3
The 2008 SYS Grid Connection Opportunities Map is shown in Insert 3.1. Insert 3.1
suggests that the zone where Damhead Creek 2 would be located requires a very low
amount of extra generation, whereas London represents a zone which requires a very
high amount of extra generation.
3.3.4
However, it is important to note that the 2008 SYS Grid Connection Opportunities
Map does not take into consideration the closures, by 2012 (approximately), of the
coal plant at Kingsnorth (2000 MW), Tilbury (1500 MW) and the oil fired plant at Grain
(1320 MW). It also assumes that Kingsnorth Power Station (Units 5 and 6), the
proposed coal plant at Tilbury and the Thames Array are constructed which is all far
from certain.
1
Information from National Grid : Seven Year Statement (2007)
June 2009
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SECTION 3
INSERT 3.1: NATIONAL GRID 2008 SEVEN YEAR STATEMENT, GRID
CONNECTIONS OPPORTUNITIES MAP
3.3.5
Therefore, there is a clear need for the development of additional power generation in
the London / south east region. As such, Damhead Creek 2 is suitably located on the
Hoo Peninsula in Kent to service this need.
3.3.6
In addition, this would reduce the potential for transmission losses that would be
associated with additional electricity generation situated in the north of the country.
3.4
History of Power Generation in Local Area
3.4.1
The Hoo Peninsula has a history of electricity generation. In the 1970 and 1980s, two
power stations were constructed. These were the:
Kingsnorth Coal Fired Power Station (Kingsnorth Units 1 – 4) with an output of
2000 MW; and
Isle of Grain Oil Fired Power Station with an output of 3300 MW.
3.4.2
This gave a total generation capacity of 5300 MW on the Hoo Peninsula. However,
the generating capacity of the Isle of Grain Oil Fired Power Station has subsequently
been reduced to 1320 MW (and may soon be closed completely) and Kingsnorth Coal
Fired Power Station expected to close before 2016.
3.4.3
This generation capacity has been, and will be, replaced by existing and proposed
power stations. These include the:
Existing Medway CCGT Power Station (750 MW)
June 2009
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SECTION 3
Existing Damhead Creek CCGT Power Station (792 MW);
Proposed Isle of Grain CHP plant (1200 MW);
Proposed Kingsnorth Supercritical Coal Fired Power Station (Kingsnorth Units 5
and 6) (1600 MW); and
Damhead Creek 2 (of up to 1000 MW).
3.4.4
This capacity within the local area will equal that installed in the 1970 and 1980s and
maintain the electrical output from the Hoo Peninsula at around 5300 MW. This can
be seen in Insert 3.2.
INSERT 3.2: HOO PENINSULA POWER GENERATION TRENDS
6000
Generating Capacity (MW)
5000
4000
3000
2000
1000
0
1979
Present
2016
Kingsnorth Units 1 - 4
Isle of Grain
Medway
Damhead Creek
Damhead Creek 2
Kingsnorth Units 5 and 6
Isle of Grain CHP
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SECTION 4
SECTION 4
LEGISLATIVE PLANNING POLICY
CONTEXT
4
4.1
Overview
4.1.1
This Section provides the planning context to the Development. It begins by
explaining the role of the development plan, which is central to policy and decision
making, it then identifies current development plan documents that are applicable to
the Development and refers to Medway Council’s programme for plan making. This is
followed by a brief explanation of national planning and energy policy sources which
are a material consideration, then the main regional and local development plan
policies relevant to the Development and how these are applicable. There is
accompanying this application a separate Planning Statement which assesses the
Development against policy.
4.1.2
In each of the topics at Sections 10-18 of the ES which present information to be
assessed in the EIA process (Electricity Works (Environmental Impact Assessment)
(England and Wales) Regulations 2000 as amended, Schedule 4), there is included a
schedule listing key planning policies to inform the assessment process of matters
considered relevant from a development plan perspective.
4.2
Legislative Context
4.2.1
As background to the relevance of “development plan”, the Planning and Compulsory
Purchase Act 2004 (PCPA) introduced powers to give effect to the Government’s
policy on the reform of the planning system. It includes a requirement for there to be
a regional spatial strategy (RSS) for each region in England.
4.2.2
The PCPA also provides for the preparation of local development documents (LDDs)
by local planning authorities (LPAs) to replace local plans and unitary development
plans, although until the relevant LDDs are approved, policies in extant plans may be
“saved”. LDDs will be specified in a LPA's local development strategy (LDS); when
approved, the LDDs will set out policies for the development and use of land in their
area, having regard, amongst other things, to the Government’s national policies, the
RSS for the region in question, the LPA's statement of community involvement (SCI),
other adopted LDDs and an appraisal of the sustainability of the proposals and a
report of the findings.
4.2.3
Section 38 (Development Plan) PCPA stipulates:
“(5)
If, to any extent, a policy contained in a development plan for an area
conflicts with another development plan the conflict must be resolved in favour of the
policy which is contained in the last document to be adopted, approved or published
(as the case may be)
(6)
If regard is to be had to the development plan for the purpose of any
determination to be made under the planning acts, the determination must be made in
accordance with the plan unless material considerations indicate otherwise”
Paragraph 4.2.6 explains the circumstances in which Section 38(5) may be
applicable.
4.2.4
Section 38(3) of the PCPA also stipulates that in England, for any area other than
Greater London, the development plan is:
(a)
“the regional spatial strategy for the region in which the area is situated; and
(b)
the development plan documents taken as a whole which have been adopted
or approved in relation to that area.”
4.2.5
The development plan documents relevant to the Development are as follows:
June 2009
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SECTION 4
CONTEXT
The South East Plan (Regional Spatial Strategy for the South East of England)
(SEP);
Kent and Medway Structure Plan 2006 (KMSP); and
Medway Local Plan 2003 (MLP).
A full transcript of the policies from the development plan documents that are
applicable to the Application is included at Appendix B.
4.2.6
The SEP was approved by the SoS on 6 May 2009 and, as such, is the most recent
of the development plan documents; therefore as required by Section 38(5) PCPA, in
the event of conflict with another development plan, policies in the SEP must be
favoured (refer to paragraph 4.2.3 above). In relation to the KMSP, the SoS has
decided that none of its policies should be extended; so these will cease to have
development plan status on 6 July 2009. Relevant policies from the KMSP have been
addressed briefly in this Section due to the Application being submitted during the
course of this overlap period. With regard to the MLP, certain of its policies were
notified as being saved on 21 September 2007 pending approval of Medway
Council’s LDF.
4.2.7
Medway Council’s SCI 2006 sets out its process of public participation in plan making.
Its LDS has been reviewed and is rolled forward to cover the period 2008-2011; the
LDS continues to be updated. Medway Council has decided to concentrate initially on
a Core Strategy and then complete an Area Action Plan for the proposed new
settlement at Chattenden/Lodge Hill; this process is planned to occur during 2010/11.
4.3
National Policy
Planning
4.3.1
Government policy in respect of land use planning is set out in planning policy
statements (PPSs), planning policy guidance (PPGs), Circulars, White Papers and
Ministerial Statements, which are material considerations that should be taken into
account where relevant. Paragraphs 4.3.2-4.3.18 provide summaries of PPSs and
PPGs relevant to the Development and the Development site; paragraphs 4.3.194.3.22 refer to various Circulars and paragraphs 4.3.23–4.3.32 to Government energy
policy and reports on progress.
4.3.2
PPS1 – Delivering Sustainable Development (2005) – addresses the Government’s
objectives for the planning system, the key principles being social cohesion and
inclusion, protection and enhancement of the environment, prudent use of natural
resources, sustainable economic development, integrating sustainable development
in development plans and delivering sustainable development including spatial plans,
design and community.
4.3.3
Planning and Climate Change – Supplement to PPS1 (2007) identifies tackling
climate change as a Government priority for the planning system. The delivery of
sustainable development is to be achieved through spatial strategies that include
contributing to the Government’s climate change programme, providing infrastructure
where it is needed, energy efficiency, reduction in emissions, minimising vulnerability
and providing resilience to climate change consistent with social cohesion/inclusion,
conserving and enhancing biodiversity, reflecting development needs and interests of
communities, responding to the concerns of business, and encouraging
competitiveness and technological change, in mitigating and adapting to climate
change. Accordingly, policies should promote renewable and low carbon energy and
supporting infrastructure (paragraph 19). “Low carbon technologies are those that
can help reduce carbon emissions. Renewable and/or low carbon energy supplies
include, but not exclusively, those from biomass and energy crops; CHP/CCHP and
(micro HP); waste heat that would otherwise be generated directly, or indirectly, from
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fossil fuel” (Glossary). Consultations regarding CHP potential are referred to in
Section 9 and the Combined Heat and Power (CHP) Assessment.
4.3.4
PPG4 – Industrial, Commercial Development and Small Firms (1992) contains advice
on the role of the planning system in relation to industrial and commercial
development and refers to one of the Government’s key aims as being to encourage
continued economic development in a way that is compatible with its environmental
objectives. PPG4 encourages the re-use of urban land and advocates a positive
approach to development control.
4.3.5
Consultation PPS4 Planning for Sustainable Economic Development (2007) sets out
the role of national planning policies to be acted upon as appropriate through positive
plan-making for economic development, using evidence to plan positively, recognising
the needs of business, efficient and effective use of land, securing a high quality and
sustainable environment and delivering a positive approach through development
control. It also requires that full consideration should be given to the economic
aspects of proposals for development and that LPAs should consider proposals
favourably unless there is good reason to believe that the economic, social and/ or
environmental costs of development are likely to outweigh the benefits
(paragraph 29). The consultation paper on a new PPS4 invites comments on
“Planning for Prosperous Economies”; it aims to update the drafts of PPS4 and PPS6
and consolidate them into a single document. The paper retains the presumption in
relation to decision making that LPAs should adopt a positive and constructive
approach to applications for economic development (Paper EC12.1). ES Section 3
explains the rationale for the Development and Section 18 the socio economic effects.
4.3.6
PPS9 - Biodiversity and Geological Conservation (2005) - sets out national policies
for the protection of biodiversity and how the conservation of natural heritage is to be
reflected in land use planning.
When considering applications for planning
permission, LPAs should maximise opportunities for building in beneficial biodiversity
as part of good design. The most important sites for biodiversity are those identified
through international conventions and European Directives. ES Section 6 refers to
ecological mitigation established and maintained as part of the existing Damhead
Creek Power Generation operation. ES Appendix G Ecological Reports informs the
EIA process; Section 13 addresses ecology, including the proximity of the
Development site to the Medway Estuary and Marshes Special Protection Area
(SPA), Ramsar Site and Site of Special Scientific Interest (SSSI). Section 9 refers to
a Statement to Inform which assesses whether the Development will result in adverse
effects on European Sites within the vicinity of the proposed Development. the
conclusion of which is that the Development will not cause a significant adverse effect
on the integrity of the relevant European Sites, alone or in combination with other
plans or projects.
4.3.7
PPS10 - Planning for Sustainable Waste Management (2005) sets out national
policies on different aspects of land use planning in England concerning the
management of waste; its overall objective being “to protect human health and the
environment by producing less waste and by using it as a resource wherever
possible”, including the consideration of waste management in the site
preparation/construction processes. It recommends that proposed new development
should be supported by waste management plans which are encouraged to identify
the volume and type of material to be demolished and/or excavated, opportunities for
the reuse and recovery of materials and to demonstrate how off-site disposal of waste
will be minimised and managed (paragraph 34). Section 15 describes the extent of
existing land contamination arising from the previous use of the site and mitigation
measures.
4.3.8
PPS11 - Regional Spatial Strategies (2004) sets out policies to be taken into account
by Regional Planning Bodies in the preparation of revisions to RSSs following
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commencement of Part I of the PCPA. These matters include provision for new
housing, priorities for the environment and transport, infrastructure, and economic
development. Annex A to the PPS is a topic based list of sources to be taken into
account, including, but not limited to air quality, biodiversity, climate change,
education, energy, environment, health, soil use, sustainable development, waste
management and Government policy on energy. Under “energy”, the annex refers to
three documents PPS22 (Renewable Energy), Energy White Paper 2003 and the
Government’s Strategy for Combined Heat and Power to 2010; the list of documents
referred to is expected to change over time.
4.3.9
PPS12 - Local Spatial Planning (2008) sets out policies to be taken into account by
LPAs in producing LDDs. Annex B refers to matters which LPAs must consider in the
preparation of development plan documents, including resources, utilities,
infrastructure and climate change.
4.3.10
PPG13 - Transport (2001) describes its objectives as being to co-ordinate land use,
planning and transport, to promote more sustainable transport choices for both people
and movement of freight, promoting accessibility and reducing the need to travel,
especially by car. Section 16 considers traffic and infrastructure and the findings of a
Transport Assessment to inform the EIA process.
4.3.11
PPG14 – Development on Unstable Land (1990) encourages the full and effective
use of land in an environmentally acceptable manner and that land which has been
damaged by industrial activities, or which is naturally unstable, can often be put to an
appropriate use and thus contribute to the broad objectives for the economic and
efficient use of land and the protection of the environment. Section 6 contains a
description of the Development site and Section 15 the nature of the geology,
hydrology and extent of land contamination; the Appendix I Ground Investigation
Report is also relevant.
4.3.12
PPG15 - Planning and the Historic Environment (1994) provides guidance in applying
the provisions of the Planning (Listed Buildings and Conservation Areas) Act 1990 to
policies for the identification and protection of historic buildings, conservation areas
and other historic assets. ES Section 17 considers cultural heritage.
4.3.13
PPG16 - Archaeology and Planning (1990) provides guidance in applying the
provisions of the Ancient Monuments and Archaeological Areas Act 1979 and policies
for the identification and protection of archaeological remains and monuments and
sets out a process for informed decision making involving remains affected by
development. Section 17 describes the archaeological potential of the Development
site. Appendix J is a Gazetteer of Archaeological Interests and Appendix K the
Archaeological Background and additional information on the archaeological
assessment.
4.3.14
PPG20 - Coastal Planning (1992) provides a statement of policy in relation to coastal
planning for England and Wales. Key policy issues for coastal planning are identified
as conservation of the natural environment, development (particularly that which
requires a coastal location) risks including flooding, erosion, land instability and
improving the environment. Section 15 refers to hydrology and to flooding and there
is a Flood Risk Assessment (Appendix H).
4.3.15
PPS22 - Renewable Energy (2004) refers to the development of alternative forms of
renewable energy which occur naturally and repeatedly in the environment, while
noting that improvements in energy efficiency and the development of CHP will make
a vital contribution to the objective of cutting carbon dioxide emissions. Consultations
regarding CHP potential are referred to in Section 9 and in the Combined Heat and
Power (CHP) Assessment.
4.3.16
PPS 23 - Planning and Pollution Control (2004) affirms that quality of land, air or
water and potential impacts arising from development may be a material planning
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consideration, and it distinguishes between planning and pollution control as
complementary regimes. In Appendix A to this PPS, matters to be considered in
preparing LDDs and decisions on individual applications, include economic and wider
social needs and alternative sites and that the nature of polluting development and
national or regional need may make availability or lack of availability of suitable
alternative sites material to the planning decision. Section 3 refers to the rationale for
development and Section 7 to site selection and alternatives. Section 10 considers
air quality and Section 14 water quality including impacts during construction and
operation.
4.3.17
PPG24 – Planning and Noise (1994) gives guidance on the use of planning powers to
minimise the adverse impacts of noise and its effects on the environment and the
quality of life. In assessing applications, LPAs should give reasonable consideration
to the compatibility of proposed activities with the surrounding uses. Section 11
considers noise and vibration and Appendix F provides a Baseline Noise Report.
4.3.18
PPS25 - Development and Flood Risk (2006) explains how flood risk should be
considered at all stages of the planning process to avoid inappropriate development
in areas at risk of flooding and to direct development away from areas at highest risk.
Reference is made to electricity generating power stations, grid and primary sub
stations as falling within the category of essential infrastructure, such that the
exception test may be applied within flood risk vulnerability clarification zones 3a/3b.
If the exception test is passed, the plant should be designed and constructed to
remain operational and safe for users in times of flooding. Section 15 considers
hydrology including flooding and there is a Flood Risk Assessment.
4.3.19
Circular 15/97 - The United Kingdom National Air Quality Strategy and Local Air
Quality Management: Guidance for Local Authorities (1997) promotes a corporate
approach to the issue of local air quality, gives an introduction to the function of local
authorities in delivering the Government’s UK National Air Quality Strategy through
the Local Air Quality Management (LAQM) system. The Development site is not
within or adjacent to an AQMA.
4.3.20
Circular 05/05 – Planning Obligations provides guidance to LPAs in England on the
use of planning obligations under Section 106 Town & Country Planning Act 1990.
Annex A to the Circular sets out the statutory framework for planning obligations;
Annex B to the Circular explains the policies of the Secretary of State and provides
guidance on the use of planning obligations which LPAs should taken into account
when determining applications and drafting policies.
4.3.21
Circular 06/2005 - Biodiversity and Geological conservation - Statutory obligations
and their impact within the planning system provides administrative guidance on the
application of the law relating to planning and nature conservation in England. It
compliments PPS9 and the Good Practice Guide. In Part I to the Circular it deals with
the conservation of internationally designated sites, SPAs (classified under the EC
Birds Directive), Special Areas of Conservation (SACs), designated under the Council
Directive 92/43 and Ramsar sites listed under the provisions of the Ramsar
convention on wetlands of international importance. Part II to the Circular deals with
SSSI and the consultation and notification of processes; Part III to the Circular covers
planning for nature conservation outside designated sites; Part IV to the Circular
deals with the conservation of species and Part V to the Circular provides advice on
other duties and the use of statutory powers. Section 6 refers to ecological mitigation
established and maintained as part of the existing Damhead Creek Power Generation
operation. Section 13 addresses ecology, including the proximity of the Development
site to the Medway Estuary and Marshes Special Protection Area (SPA), Ramsar Site
and Site of Special Scientific Interest (SSSI) and to a Statement to Inform which
assesses whether the Development will result in adverse effects on European Sites.
The conclusion of the Statement to Inform is that the Development will not cause a
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significant adverse effect on the integrity of the relevant European Sites, alone or in
combination with other plans or projects. Appendix G Ecological Reports informs the
EIA process.
4.3.22
Circular 1/2006 Guidance on Changes to the Development Control System (2006)
provides guidance on changes to the development control system. Section 3 to the
Circular refers to amendments to the 1990 Act which prohibits, among other things,
an LPA from entertaining an application unless it is accompanied by a design
statement and an access statement where required. A design and access statement
is described at paragraph 6.0 of the Circular as “a short report accompanying and
supporting a planning application to illustrate the process that has led to the
development proposal and to explain and justify the proposal in a structured way.”
The Application is accompanied by a Design and Access Statement.
Energy
4.3.23
Government energy policy is represented in the following documents, which are
material to a consideration of the Development; reference is also made to the
objectives of reducing carbon dioxide emissions while maintaining security of supplies
along with reports on the need for additional generating capacity and the
Government’s commitment to the role of carbon capture storage (CCS). The ES
explains in Section 3 the need for additional power generation plant in London/South
East region and the fact that the location of this Development on the Hoo Peninsula is
well located to serve this need and in Section 7 that the operation of Damhead
Creek 2 can make a significant contribution to reducing CO2 emission levels. It is
also further explained in Section 9 that CHP will improve the energy utilisation of
Damhead Creek 2, thereby helping to reduce the generation of greenhouse gases
and that the Development will be designed to be CCR.
4.3.24
Our Energy Future - Creating a Low Carbon Economy” Cm 5761 (Energy White
Paper) (2003) – identifies three challenges, first climate change, second decline in the
UK’s indigenous energy suppliers and third, the need to update much of the UK’s
energy infrastructure. The White Paper refers to four goals: reducing carbon
emissions, maintaining reliability of energy supplies, promoting competitive energy
markets and ensuring every home is adequately and affordably heated. To achieve
these goals, Government identifies “energy efficiency” as likely to be the cheapest
and safest way of addressing all four objectives with renewable energy playing an
important part in reducing carbon emissions and strengthening energy security
(paragraph 1.19).
4.3.25
The Government’s Strategy for Combined Heat and Power for 2010 (DEFRA CHP
Strategy) reflects Government’s belief that combined heat and power (CHP) has an
important role to play in achieving the aims of the 2003 White Paper. Whilst there is a
view expressed that the country will fall short of its 10% 2010 target, it is also
indicated that the measures introduced by the Government will contribute to future
development of CHP. Consultations regarding CHP potential are referred to in
Section 9 and the Combined Heat and Power (CHP) Assessment.
4.3.26
Climate Change - the UK Programme 2006/2007/2008. The 2006 document
discusses the international challenge of climate change, delivering emissions
reductions, and adapting to the impact of climate change. It notes that “The energy
supply sector has contributed a large reduction in the UK’s greenhouse gas emissions
over the past decade … largely through the switch away from more carbon intensive
fuels such as coal and oil towards low or zero carbon emissions fuels such as gas,
nuclear and renewables.” It predicts that emissions will fall further “through to 2010
as a result of the impact on electricity demand of existing measures and a further
increase in the share of gas fired electricity generation” (Energy Supply page 32).
Subsequently, the 2007 Annual Report to Parliament indicated a reverse trend, in
which fuel switching (as a result of price changes) from natural gas to coal for
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electricity generation was considered primarily responsible for carbon dioxide
emissions in 2006 being higher than in 2005 (page 11, paragraph 18). However, the
2008 Annual Report shows carbon dioxide emissions during 2007 being lower than
the 2006 figure, resulting from fuel switching back from coal to gas (Overview, page 9,
paragraph 4).
4.3.27
The Energy Challenge – Energy Review (2006) Cm 6887 - identifies two major longterm challenges, tackling climate change as global carbon emissions continue to grow
and, delivering secure and clean energy at affordable prices as the UK becomes
increasingly dependent on imports for its energy needs. On the matter of electricity
generation, it is stated that “Over the next two decades, the UK will need substantial
new investment in electricity generation capacity to replace closing coal, oil and
nuclear power stations and to meet expected growth in electricity demand” (Cm 6887
paragraph 6.4.3). It advises that it is for the private sector to make the necessary
investment decisions within the regulatory framework set by the Government and for
Government to ensure that this framework provides the right incentives, consistent
with the goal of moving to a low carbon economy.
4.3.28
Meeting the Energy Challenge – A White Paper on Energy (2007) Cm 7124 building
on the principles set out in the 2003 White Paper, identifies two long term energy
challenges of tackling climate change by reducing carbon dioxide emissions and
ensuring secure, clean and affordable energy. It addresses energy and climate
security, saving energy, heat and distributed generation, the utilisation of oil/gas/coal,
electricity generation including investment frameworks, renewables, cleaner
coal/carbon capture/storage for fossil fuels and nuclear power research and
development, transport, planning and other matters. It is predicted that some 22.5
GW of existing power stations may close by 2020 and that to maintain levels of
capacity equivalent to those of today, new generating capacity needs to be built to
meet these closures and increases in demand, in the order of 20-25 GW by 2020
(White Paper 2007 5.1.11).
4.3.29
Towards Carbon Capture and Storage – Consultation June 2008, restates the
Government’s energy strategy set out in the 2007 Energy White Paper, with its aims
“to provide the UK with secure energy supplies and contribute to the global climate
change effort” and that it also expects “fossil fuels to remain a vital part of our diverse
electricity generation mix, as an essential contributor to our security of supply.”
(Executive Summary page 3). The consultation acknowledges that there is no
practical experience of operating such a facility at a commercial scale but points to
progress on the regulatory and policy framework within which CCS should operate at
national and EU levels. Since this consultation, a draft directive has been adopted by
the European Parliament which if enacted would have the effect of requiring all
combustion plants of 300 MW or more, licensed after the entry into force of the
directive to meet certain CCR criteria.
4.3.30
Towards Carbon Capture and Storage – Government Response April 2009. The
Government response to the Consultation (April 2009) notes that “The agreed
Directive however arguably does not require CCR for new plants, since allocation of
space is only mandatory if the required assessments demonstrate CCS is feasible at
a later date” (paragraph 1.16). “However, given the importance of climate change
targets and taking account of responses to the consultation, it is the Government’s
intention not to consent any future applications for new combustion stations at or over
300 MWe unless they can be deemed CCR…” (paragraph 1.20). The issue of CCR is
discussed in Section 19 and the Carbon Capture Readiness (CCR) Feasibility Study.
4.3.31
DECC’s Energy Markets Outlook Report (December 2008) (EMOR) refers to the main
causes of interruption to energy supply, the additional challenges that will be faced as
a consequence of closures (particularly coal plant) by 2016 under the Large
Combustion Plants Directive and the expectation of increasing diversity of potential
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sources of gas supply. The Government’s expressed view is that independently
regulated competitive energy markets with an appropriate cost of carbon and support
for emerging low carbon technologies is the way forward and that “the best way to
deal with future uncertainties is to ensure that the market has access to all
technologies”. It notes that coal and gas fired plant have the advantage of being able
to operate flexibly, regardless of weather conditions. EMOR predicts that around 12
GW of coal and oil fired generating plant which “opted out” will have to close by not
later than the end of 2015 and around 7.3 GW of older nuclear capacity is scheduled
to close by 2020.
4.3.32
Ofgem’s “Sustainable Development Report” November 2007 notes that while the
country is likely to meet its present greenhouse gas emissions targets of 12.5% below
base year (1990) levels by 2008-2012 under the Kyoto Protocol. “This has been
largely driven by the switching from coal to gas fired electricity production over this
period”, which is a reminder of the positive role that has been played by investment in
CCGT and other gas fired generating plant (paragraph 3.1). The subsequent Ofgem
Sustainable Development Report December 2008 re-affirms the Government’s
commitment to facilitating transition to a low carbon economy and to delivering long
term secure energy supplies (paragraph 1.7). At the same time, it points to the fact
that in the UK “companies will need to make substantial new investment in power
stations, the electricity grid and gas infrastructure” (paragraph 1.8). It is also pointed
out that CCS will be an important technology for the shift to achieve a low carbon
economy.
4.4
Regional Policy
South East Plan
4.4.1
The South East Regional Assembly submitted the draft SEP to Government on 31
March 2006; consultation on the draft plan was from 31 March 2006 – 23 June 2006
and the examination in public (EIP) ran from 28 November 2006 to 30 March 2007.
The report of the assessment was published by the Government Office for the South
East on 29 August 2007 and the SoS published her Proposed Changes to the draft
SEP on 17 July 2008, with consultation ending on 24 October 2008. The SEP was
published on 6 May 2009 and replaces Regional Planning Guidance for the South
East (RPG9 2001). The SEP is the most recent statement of development plan
policy; it affords particular support for investment in the Kent Thames Gateway, within
which the Application site is located in the SEP. Policies include the aim to achieve
reductions in CO2 emissions by various means, including enhanced energy efficiency,
recognising the demands on infrastructure utilisation and provision and the
requirement for development to address particularly the re-use of land for investment,
stabilisation of the ecology footprint, emphasis on the protection of sites to which the
Habitats Directive applies and consideration of flood risk.
Spatial Strategy
4.4.2
Policy SP1 identifies nine sub-regions of which one is the Kent Thames Gateway
(which includes the Medway Towns), where the focus will be on growth and
regeneration; requiring better alignment of economic and housing growth and delivery
of adequate infrastructure in a timely manner while planning for more sustainable
development. Policy SP4 sets out a regeneration policy framework for those parts of
the region with a relatively low economic performance and high deprivation; Kent
Thames Estuary is one of the sub-regions where extensive regeneration is needed.
Cross Cutting
4.4.3
Policies CC1, CC2, CC3 concern the delivery of sustainable development, climate
change and resource use. The principal objective of the SEP, described in
Policy CC1, is to achieve and maintain sustainable development in the region in
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which priorities are, achieving sustainable levels of resource use,
conservation/enhancement of the physical/natural environment, reducing greenhouse
gas emissions, preparing for climate change and ensuring that everyone including the
most deprived people have equal opportunities; this policy is also applicable to other
aspects of development including energy, re-use of land, ecology and flood risk
(Policy CC1). Measures will be taken to mitigate/adapt to climate change and to help
reduce CO2 emissions by at least 20% below 1990 levels by 2010, 25% by 2015 and
80% for 2050 with a target for 2026 incorporated in the first review of the plan.
Reduction of greenhouse gases will be achieved primarily through greater resource
efficiency, including enhanced energy efficiency and carbon performance of
buildings/people, reducing the need to travel, achieving sustainable modes of
transport, land use that acts as carbon sinks, renewable energy and reducing
landfilling of biodegradable waste (Policy CC2). On the matter of resource use, there
will be a sustained programme to help stabilise the ecological footprint by 2016 and
reduce it further by 2026 including increased efficiency of resource use (Policy CC3).
4.4.4
Section 7, in its comparison of impacts of new types of generating plant,
demonstrates that the choice of a CCGT plant, as a means of generating electricity,
would result in significantly lower emissions than conventional coal/oil fired plant and
thereby contribute to Government policy of reducing CO2 emissions whilst maintaining
electricity supplies. The Section also refers to ScottishPower’s approach to its
consideration of alternative development sites in the South East of England and that
the Application site was chosen because it fulfilled important criteria, including its
proximity to infrastructure. Section 6 describes an extensive area of ecological
mitigation land, established and maintained as part of the existing Damhead Creek
Power Station development, which is owned and managed by ScottishPower and
borders the Development site. Section 13 reports on mitigation to valued ecological
receptors and confirms that post-mitigation construction and operational phases will
not result in any significant impact.
4.4.5
Policies CC4, CC7, CC8 address sustainable design/construction, infrastructure
implementation and green infrastructure. All development will be expected to adapt
and incorporate sustainable construction standards/techniques, to include
energy/water efficiency, biodiversity gain and a proportion of energy from
decentralised and renewable or low carbon sources and to promote best practice in
sustainable construction (Policy CC4). The scale and pace of development will
depend on sufficient capacity being available in existing infrastructure; where this
cannot be demonstrated, it will depend on additional capacity being released through
demand management measures, better management of existing infrastructure, and/or
the provision of new infrastructure (Policy CC7); for the purposes of the plan
“infrastructure”, includes utility services (gas, electricity, heat, water supplies, waste
water treatment, telecommunications infrastructure). Green infrastructure assets are
to be managed, linking environmental/social benefits, including conserving/enhancing
biodiversity, which will be particularly important in areas designated as regional hubs
(Policy CC8). Section 7 refers to the contribution made by the Development to the
Government’s policy of reducing CO2 emissions and to the potential for CHP.
ES Section 13 sets out the approach to achieve a net ecological gain.
Sustainable Economic Development
4.4.6
Policies RE1, RE2, RE3, RE4, RE6 address the UK’s long term competitiveness,
supporting nationally/regionally important sectors/clusters, employment and land
provision, human resource development, competitiveness and addressing structural
economic weaknesses. The regional economy is to contribute fully to the UK’s long
term competitiveness, while being sufficiently flexible to respond to changes in the
economy and the region’s changing economic needs (Policy RE1). The development
of nationally and regionally important sectors and clusters will be supported and,
where appropriate, will ensure that land/premises are available and encourage local
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assets that can facilitate development of sectors/clusters (Policy RE2). Sectoral
composition of the economy has been changing and LDDs are to “facilitate a flexible
supply of land to meet the varying needs of the economic sectors”. “Accessible and
well located industrial/commercial sites should be retained where there is a good
prospect of employment use.” Based as “evidence”, LDDs should meet general
needs in locations that are accessible to labour and make efficient use of
existing/underused sites through increased density, focussed on urban areas and
which promote the use of public transport (Policy RE3), however, some surplus land
may be re-allocated for alternative uses. The aim is to maintain/enhance the
competitiveness of the most economically successful parts of the region and also to
address structural economic weaknesses in areas which are underperforming such as
Kent Thames Gateway, where LDDs will give priority to delivering economic
development in allocating land, while protecting industrial/commercial sites where
there is a good prospect of good employment land use (Policy RE6). Section 3
describes the need for additional generating capacity; Section 7 explains its
consideration of alternative development sites. Accordingly, the expansion of
ScottishPower’s energy generating capability at the Development site is consistent
with these policies.
4.4.7
Policy RE4 concerning human resource development, wants skills to meet business
requirements and the workforce to be equipped to access and benefit from
opportunities. Among the areas where partners should focus are intermediate and
technician level skill shortages, improving skills/qualifications and upskilling in areas
where levels of productivity are below the regional average. ScottishPower’s ethos of
investing in people is compatible with this policy objective and is described in
Section 18 and particularly the establishment of ScottishPower Learning and its focus
on improving employment skills and work based training.
Transport
4.4.8
Policies T1, T2, T4, T5, T7, T10, T12 adopt a manage and invest strategy, mobility
management, parking, travel plans, rural transport, ports/short sea shipping and
freight/site safeguarding. Policies and proposals should address a range of measures
including mobility management, rebalancing of the transport system in favour of
sustainable modes, public transport service and reducing average journey lengths
(Policy T1). Mobility management aims include rebalancing the transport system in
favour of sustainable modes of transport including improvements in the extent and
quality of pedestrian and cycle routes, incentives for car sharing and e-services to
reduce the need to travel (Policy T2). Restraint based maximum levels of parking
linked to integrated public transport systems will be required (Policy T4). Plans must
identify categories of major travel generating development for which travel plans
should be developed (Policy T5) and encourage community based transport in areas
of need and develop innovative approaches to transport in rural areas (Policy T7).
The role of Medway Thamesport and infrastructure investment underpinning short sea
shipping connections should be supported (Policy T10) and wharves, depots and
sites critical to moving freight by rail/water protected (Policy T12). Section 16,
informed by the accompanying Transport Assessment, refers to the potential during
construction of abnormal loads causing occasional interference to other road users
and cumulative transportation issues, however, this would be organised and timed to
minimise disruption through a Transport Management Plan. Overall, the impacts on
the local road network directly associated with the Development are identified as
being insignificant.
Natural Resource Management
4.4.9
Policies NRM1, NRM2, NRM4, NRM5, NRM7, NRM8, NRM9, NRM10, NRM11,
NRM12, NRM16 are relevant, in which the region’s key environmental challenges are
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identified as water resources, water quality, flooding, biodiversity, woodland, coastal
management, air quality, noise, energy efficiency, renewable energy and CHP.
4.4.10
Policies NRM1, NRM2 address sustainable water resources/ground water and water
quality. A twin-track approach of demand management and water resource
development will be pursued to achieve sustainable drainage solutions and other
sustainable land management practices including flood storage capacity
(Policy NRM1). Water quality will be maintained and enhanced by adverse effects of
development on the water environment, including identification of infrastructure needs
and incorporating sustainable drainage systems (SUDS) (Policy NRM2).
The
Development raises no exceptional issues; during normal operation, water will only be
required on a day to day basis for make up of the boiler water system. The drainage
system will include balancing provision for increased run off and will include SUDS
measures, where practicable.
4.4.11
Polices NRM4, NRM5, NRM7, NRM8 address sustainable flood risk management,
conservation and improvement of biodiversity, woodland and coastal management.
The sequential approach to development in flood risk areas set out in PPS25 will be
followed; inappropriate development will not be permitted in flood zones 2/3 unless
there is an overriding need and absence of suitable alternatives. Existing flood
defences will be protected from development, however where development is
permitted in floodplains it must be designed to be resilient to flooding and allow for
future maintenance, re-alignment and management of the defences (Policy NRM4).
LPAs are to avoid a net loss of biodiversity and actively pursue opportunities to
achieve a net gain giving the highest level of protection to sites of international nature
conservation importance; LPAs must determine that plan/projects will not have an
adverse effect on such sites, otherwise they must not be approved (Policy NRM5).
The Statement to Inform has concluded that the development of Damhead Creek 2
would not cause any significant adverse effect on the integrity of the relevant
European Sites, either alone or in combination with the Development of Kingsnorth
Units 5 and 6 and the Kingsnorth Business Park (Section 9). The value and character
of the region’s woodland is to be protected and supported; woodland should be
extended where appropriate and woodland lost through development must be
replaced (Policy NRM7). With regard to coastal areas, there is to be an integrated
approach to coastal management and planning, taking account of climate change,
conservation/enhancement of the most valuable habitats/environments ensuring
development does not prejudice future options for managed realignment, avoiding
building on the undeveloped coastline, preventing development on unstable land,
realising opportunities for sustainable coastal defences and considering whether
planning permission should be time limited (Policy NRM8).
The Flood Risk
Assessment reports that the Development has applied an Exception Test in
accordance with PPS25 and is considered to meet those requirements. Moreover, it
finds that the Development site is protected by defences, which provide an adequate
level of protection and that the development will not increase the risk of flooding either
on site or elsewhere.
4.4.12
Policies NRM9, NRM10 address air quality and noise. The plan requires sustaining
the current downward trend in air pollution, ensuring consistency with Air Quality
Management Plans, reducing environmental impacts of transport, reducing exposure
to poor air quality through design, encouraging best practice during construction, to
reduce air pollution and assessing impacts of new development/traffic levels on
internationally designated nature conservation sites (Policy NRM9). Reduction in
noise pollution is to be achieved by locating new residential and other sensitive
development away from significant noise sources (Policy NRM10). Impacts in relation
to air quality will not be significant either independently or other development. With
regard to noise emissions, Section 11 is clear that with mitigation during construction,
no significant impact is predicted and that, when operational, when assessed against
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background noise levels relative to noise sensitive receptors, noise from the
Development plant will be negligible.
4.4.13
Policies NRM11, NRM12, NRM16 are concerned with development design for energy
efficiency and renewable energy, CHP and renewable energy development criteria.
Decentralised and renewable or low carbon energy is to be encouraged and new
development should secure at least 10% of its energy from such sources unless this
is not feasible or viable (Policy NRM11). The integration of CHP in all developments
and district heating infrastructure in large scale mixed use developments is to be
encouraged (Policy NRM12). The development of renewable energy should be
encouraged in all development and LDDs should include criteria based policies that
consider the contribution the development will make towards renewable energy
targets/carbon dioxide saving, potential integration with development, benefits to
communities, the proximity of biomass combustion plant to fuel sources, adequacy of
the local transport networks and the availability of a suitable connection to the
electricity distribution network (Policy NRM16). Section 3 refers to a need for
additional generating capacity in the region and to which this Development is well
able to contribute by virtue of its location and ability to use existing infrastructure.
Similarly, Section 7 explains the contribution made by the Development in terms of
reduced CO2 emissions. Consultations regarding CHP potential are referred to in
Section 9.4 and the Combined Heat and Power (CHP) Assessment. The latter
identifies the most likely user of heat as the proposed Kingsnorth Business Park
situated immediately to the north of the proposed Development; it also refers to other
future development at Chattenden.
Countryside and Landscape Management
4.4.14
Policy C4, encourages positive and high quality of the region’s open countryside with
the aim of protecting and enhancing diversity and local distinctiveness of landscapes.
Section 12 has assessed the visual impact of the Development as varying from
neutral to slight adverse, to moderate adverse and that the Development would not
have any significant effect on local landscape. The conclusion in Section 12 is that
the cumulative impact of the Development together with Kingsnorth Units 5/6 and
Kingsnorth Business Park, although significant, would be reduced were the other
developments to be constructed as the industrial setting would increase. Policy BE6
requires sustainable management of the historic environment with priority afforded to
the region’s internationally and nationally designated historic assets.
In its
consideration of cultural heritage, Section 17 reports that the impact on
archaeological and palaeo-environmental remains will be slight-adverse without
mitigation but that an archaeological watching brief is proposed to be employed
during construction.
Kent Thames Gateway
4.4.15
Policies KTG1, KTG2, KTG3 concern the core strategy, economic growth and
employment locations. Considerations of all stakeholders concerned with service
provision and infrastructure include, as a first priority, to make full use of previously
developed land, locate major development at Ebbsfleet, the Medway Towns and
locations served by the Channel Tunnel Rail Link (CTRL), ensure the benefits of new
services/employment are available to local communities where they are accessible by
transport, raise standards of education/skills in the workforce and set high standards
for design (Policy KTG1). The ES describes the site as being previously used
(Sections 2, 6, 15) and while the site is not within the Medway Towns, it is clear that
the Development is best sited in this location, where there is access to existing
energy infrastructure and for the other reasons indicated (Section 7). The site
location is also conveniently located relative to the proposed development by
Goodman and possibly Chattenden as described in the CHP Assessment, which will
be of local benefit. On the matter of employment and raising standards, the
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ScottishPower business philosophy towards working within communities is described
in the ES at Section 18, with particular reference to ScottishPower Learning
(paragraph 18.6.12).
4.4.16
The economy is to be widely based with provision for expansion of existing economic
functions as well as the introduction of new large scale offices, manufacturing,
services, higher value activity (including knowledge industries and R&D). “Major sites
identified in Medway will be developed to their full potential, building on the existing
high technology aerospace and automotive sectors and attaching new high value
activity, or accommodating the expansion of transport, energy, distribution and
manufacturing” (Policy KTG2). The SEP explains that the economy of the Kent
Thames Gateway is different from most other parts of the South East; power
generation is seen as one of the essential functions for the region, London and the
nation, to which Damhead Creek 2 will contribute; accordingly the use of land for that
purpose would be consistent with policy.
4.4.17
A range of readily available sites and premises are to be provided to meet the needs
of new business start ups, growing businesses and inward investors and give priority
to the completion of major employment sites in locations, (including Medway), where
new employment should be provided in conjunction with new housing. In Medway
and Swale, if existing employment sites fail to provide immediately available land for a
variety of business types, the use of the land should be reviewed and alternative sites
allocated, taking into account Policy RE3 (Policy KTG3). It is noted that “Some major
sites in the sub-region have been slow to develop, and much of the recent
employment increase has been in activities that are not located on major business
sites. Policy KTG3 not only provides for major employment sites but also provides
more widely for new employment locations. Concentrations of small businesses and
workshops at the core of the urban areas, plus education and other services, can
create important locations for new employment particularly at coastal towns with low
costs and high quality environments. Town centres are important concentrations of
retail, business services, finance and leisure and have the capacity to increase the
number of jobs on offer” (paragraph 9.14). Section 7 explains ScottishPower’s choice
of location within the region and the criteria involved in site selection and that the
Development site was the most highly scored. Section 2 also describes the
advantages of the Development site.
4.4.18
Policy KTG6 addresses flood risk. In the consideration of flood risk, strategic flood
risk assessments will be kept up to date; developments will be planned to avoid the
risk of flooding and there will be a risk based approach to guide categories of
development away from flood risk areas. Development proposals should be
accompanied by flood risk assessments and identify opportunities for flood storage
areas to contribute to green infrastructure networks (Policy KTG6). Policy KTG7
concerns green initiatives arising from the Thames Gateway Parklands aim of
transforming the environment and the aspiration for the Thames Gateway to be
Europe’s first Eco-Region. The policy makes provision for joined up green grid
networks including enhancement of landscape, habitats, heritage and the
environment. Chapter 15 confirms that the Flood Risk Assessment (Appendix H)
finds that, in accordance with PPS25, the Development is considered to meet the
requirements pass the Exception Test. Section 13 sets out the approach to achieving
a net ecological gain.
4.5
Kent and Medway Structure Plan
4.5.1
The KMSP, jointly produced by KCC and Medway Council, sets out the strategic
planning framework for their respective areas, covering the natural environment,
quality of life, economic development, housing, transport, natural resources,
management of waste and minerals and implementation. As background, it refers to
superseded RPG9 2001 and to the Government’s Sustainable Communities Plan
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2003 in which Thames Gateway - North Kent, is seen as a national and regionally
important area for economic regeneration and for redeveloping previously used land
(KMSP 1.15). It has been noted in this Section that the KMSP policies will cease to
have development plan status on 6 July 2009 (refer to paragraph 4.2.6 above),
nevertheless it is worth recording that the plan prioritisation support for Kent Thames
Gateway, encourages the use of previously used land and recognises Kent’s role in
the production of energy.
Vision and Guiding Principles
4.5.2
Policy SP1 is about conserving and enhancing Kent’s environment and ensuring a
sustainable pattern of development. The means by which this will be done include
protecting the countryside and wildlife, reducing reliance on greenfield sites, using/reusing land more efficiently, protecting/enhancing features of importance in the
natural/built environment, reducing the need to travel, encouraging high quality
development, timely provision of housing/employment infrastructure/community
services, supporting restrictions/growth of employment, support for rural areas and
responding to climate change by conservation/prudent use of energy/water/natural
resources, minimising pollution/assisting the control of greenhouse gas emissions and
safeguarding areas of potential flood risk from development. Section 3 describes the
rationale and the need for the development; Section 5 describes the proposed
development; Section 6 describes the Development site and its surroundings;
Section 7 the selection process and the criteria by which the site was identified as the
most highly scored.
Spatial Strategy
4.5.3
Policies SS1 and SS4 concern spatial priorities for development, investment in Kent
and the role of the settlement hierarchy and prioritise the use previously developed
land and the sequential approach to the location of development. The plan includes
in its priorities, support for Kent Thames Gateway with much of the new development
concentrated at Kent Thameside including the Medway Towns (Policy SS1). In the
preparation of LDDs, “development requirements which are not met by sites with
existing planning permission should be provided through the consideration, of first,
previously developed land …”; assessment of locations should follow the sequential
consideration of sites, including Policy EP3 (location of new/replacement employment
land) (Policy SS4). The proposed Development is within the Kent Thames Gateway
on land which is identified for development. Section 6 describes the Development
site as comprising some unmanaged grass land, a substantial area of hardstanding
and land used for the disposal of fly ash; all of this land is identified for development,
accordingly the Development is considered to be consistent with the sequential
approach.
Medway
4.5.4
Policy ME1, concerning Medway, sees regeneration as focussing on the Medway
Waterfront, while expansion beyond the Medway urban area will be concentrated at
Chattenden/Lodge Hill on previously developed land, or such alternatives as may be
identified in LDDs in the event that the former MOD land fails to come forward. The
KMSP envisages improvements to the A228 along with rail access to support the
growth of Thamesport and industrial/commercial development at Grain and
Kingsnorth. Such improvements are seen as important to take forward the strategic
land allocations at Grain and Kingsnorth and to effect linkages with the Medway
Urban Area and Chattenden/Lodge Hill; Grain is identified as being nationally
important for the energy sector (KMSP 3.2.1). The Development represents a major
investment in energy generation infrastructure, for which need has been identified
(Section 3).
Protecting/Enhancing Natural Environment
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4.5.5
Policies EN1, EN2, EN3, EN5, EN9, EN12 concern protecting the countryside,
coast/estuaries,
countryside
character,
special
landscape
areas,
trees/woodland/hedgerows and river corridors. The countryside and undeveloped
coast/estuaries are to be protected, conserved and enhanced (Policies EN1, EN2),
similarly landscape and wildlife habitats (Policy EN3). The primary objective of
special landscape area designations is the protection, conservation and enhancement
of the quality of their landscapes; North Kent Marshes is contiguous to the site
(Policy EN5).
Trees, woodland, hedgerows and river corridors contribute to
landscape character, wildlife habitats and biodiversity; they should be protected and
enhanced where possible (Policies EN9, EN12). The proposed Development site is
within an area identified for development; it is close to but is not within an area of
countryside but rather is adjacent to an area of developed coast. Section 12 has
considered landscape and visual impact. Section 20 proposes that the architectural
design process will be sensitive to the suggestions of the LPA and will provide a high
standard of visual amenity, subject to practical and economic considerations. The
site described in Section 6 comprises mainly open land; its development does not
impinge on woodland and hedgerows, nor on existing public access to the river
corridor.
4.5.6
Policies EN6, EN7, EN8 relate to international/national and county/local wildlife
designations and to the overall protection, conservation and enhancement of
biodiversity. Development will not be permitted if it would harm the scientific or nature
conservation interests of a European site, proposed European Site, Ramsar site,
SSSI or national nature reserve (Policy EN6), or local nature reserve, county wildlife
site or regionally important geological/geomorphological site (Policy EN7) or
adversely effect other important habitats or species (Policy EN8). Issues concerning
ecology have been considered in Section 13, confirming that development will not
cause an adverse effect on the integrity of such sites and that mitigation measures
will further reduce the risk of impact.
Quality of Life
4.5.7
Policy QL1 requires that all development should be well designed and be of a high
quality. Innovative design will be encouraged where appropriate; the principles of the
Kent Design Guide will be applied and applications should include a design and
access statement. Policy QL7 concerns archaeological sites and requires that the
integrity of Scheduled Ancient Monuments and other important archaeological sites
together with their settings will be protected and, where possible, enhanced. Design
considerations are considered in Section 20. Section 17 confirms that development
of Damhead Creek 2 will not significantly affect the setting of any Scheduled Ancient
Monument.
Employment
4.5.8
Policies EP1, EP2, EP4 address land/workforce/education/skills, employment land
provision and locations of strategic importance for employment use. Sufficient
land/floorspace is to be provided to sustain full employment and reduce the need to
travel. The “varied character of the employment land, together with the development
of other economic sectors”, is to provide opportunities for the workforce as a whole,
while the improvement of skills and qualifications of the workforce and the consequent
development of the economy is to be supported (Policy EP1). Priority will be given to
developing sites with planning permission or identified in plans for the full range of
employment uses; additionally new land will be identified, including in Medway at
least 20 hectares for a range of employment at Chattenden/Lodge Hill. Existing
employment sites that are well located and well suited for employment use shall be
retained but may be reviewed through LDDs where constraints exist and may be
replaced by alternative sites. Employment uses, other than those covered by
Policy EP2, may be included on the major sites, provided this does not conflict with
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policies, notably in respect of the location of major generators of travel (Policy EP2).
In contributing to the provisions of Policy EP2, the safeguarding and implementation
of strategic employment sites, including Medway Kingsnorth and Grain, will have
priority for business, industrial and distribution uses (Policy EP4).
4.5.9
Section 18 explains that skilled operators will make up the large majority of the
operational workforce; they will receive additional training from the manufacturer of
the Development plant, with responsibility transferred to the operating staff during the
commissioning phase. ScottishPower's learning programme is focused on improving
the employment of young people through the teaching development of a broad range
of key employment skills, all of which indicates broad compliance with Policy EP1 in
its focus on the workforce, education and skills. Section 3 describes the distribution
of energy generation within the UK as being in the northern part of the country
compared with the main electricity demand being in the South of England, particularly
in London, the South East, the South West and some parts of the Midlands where
demand is increasing and to the consequent transmission losses arising from the
transmission of electricity over long distances. Section 7 sets out the main
requirements for site selection, while Section 2 describes the advantages of the
Development site as including its proximity to existing facilities at Damhead Creek
Power Station, the presence of the existing gas main which was sized to serve further
generation capacity and the proximity to the National Grid. Other locational
characteristics of the area, namely the existing Damhead Creek Power Station, the
E.ON Kingsnorth Power Station and the Development site’s proximity to other
industrial/commercial development, make the site’s location attractive to power
generation.
Managing Our Natural Resources
4.5.10
Policies NR1, NR2, NR4, NR5, NR7, NR8, NR10 address the prudent use of natural
resources, energy generation, CHP, pollution impacts, Air Quality Management Areas
(AQMAs), water quality, development and flood risk. Proposals for development
should incorporate sustainable construction techniques and contribute to conservation
and prudent use of natural resources (including energy, water with provision for
recycling, water consumption and energy efficiency) and achieving reduction in
greenhouse gas emissions (Policy NR1). On the matter of energy provision, it is
noted that it is essential but that its provision should do as little harm as possible;
Kent has a tradition of power production, reflecting its proximity to London, and while
alternatives to fossil fuels are to be considered, due to concerns about supplies and
the effects of CO2 emissions; renewable and sustainable energy forms, including
CHP, are seen as opportunities to be considered (KMSP 9.7-9.27). Proposals for
energy generation will be assessed in terms of impact on landscape, nature
conservation, health, built environment, air quality, atmosphere, water resource
interests, effectiveness of mitigation measures, proximity to energy sources,
contribution to meeting local community energy needs, prospective life of the plant
and site restoration (Policy NR2). Proposals for CHP will be supported and LDDs
should assess and, where viable, provide for CHP in the planning of major
development proposals (Policy NR4). The quality of the environment will be
conserved and enhanced, including visual, ecological, geological, historic, water
environments, air quality, noise, levels of tranquillity and light intrusion; pollution
impacts could be avoided or adequately mitigated (Policy NR5). Development in or
adjoining AQMAs should be controlled so as to not adversely affect the position
(Policy NR7), nor should development give rise to unacceptable impacts on the
quality or yield of watercourses, coastal waters and/or groundwater resources
(Policy NR8). Development should be planned to avoid the risk of flooding; however
where it is necessary in areas at risk, it should be designed and controlled to mitigate
the impacts of flood risk. LDDs will ensure a risk based sequential approach to
development, reflecting degrees of flood risk by securing appropriate drainage
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systems, requiring flood risk assessments and seeking to create wetland wildlife
habitats (Policy NR10).
4.5.11
Section 7 refers to the relative efficiencies of different forms of generating plant and
that the operation of the CCGT Development can make a significant contribution to
the Government’s policy of reducing CO2 emissions. Similarly, Section 2 has
described the advantages of the Development site as including its ability to share
existing facilities at Damhead Creek Power Station and to utilise existing
infrastructure while affording the opportunity for CHP in the vicinity should demand
arise. Section 10 has confirmed that impacts arising from construction and various
operational scenarios will not be significant and that neither will there be significant
cumulative effects associated with the parallel operation of the Project alongside the
existing Damhead Creek Power Station and the proposed Kingsnorth Units 5 and 6.
Sections 14 and 15 confirm that all water effluent/discharges arising from the Project
will be in accordance with limits set by the Environment Agency and that the site is
not considered to be at risk from flooding.
Transport
4.5.12
Policies TP1, TP2, TP3, TP11, TP14, TP15, TP17, TP19 concern integrated transport
strategy, assessment criteria for transport proposals, transport and the location of
development, facilities for pedestrians and cyclists, safeguarding of railway land for
transport, development traffic and heavy goods vehicles and vehicle parking
standards. The transport planning strategy is designed to achieve a sustainable
approach to transport, reducing the need to travel, traffic and management of minor
roads, to locate development where it is served by a choice of means of transport,
making better use of the existing network and to encourage public transport, walking
and cycling in preference to the private car (Policy TP1). Assessment criteria will
include a sustainable pattern of development, effects on the environment including
emissions, reducing dependence on the car, concentrating traffic on the most suitable
routes and accommodating improvements for buses, pedestrians and cyclists
(Policy TP2). Sites should be well served by public transport, walking and cycling;
travel plans should be established for larger developments and schemes likely to
generate a large number of trips should have/achieve a good choice of transport
(Policy TP3). Facilities for pedestrians and cyclists should be provided, their use
promoted and be addressed in schemes at the design stage (Policy TP11) Land
formerly used for railways will be safeguarded (Policy TP14).
Development
generating significant HGV movements should be well related to the
primary/secondary road network and to achieve the distribution of goods by
sustainable means in urban areas (Policy TP15). Through traffic, particularly goods
vehicles, should be discouraged from travelling on minor roads by traffic management
measures (Policy TP 17). There are maximum vehicle parking standards, however
more stringent measures may be applied (Policy TP19). It has been confirmed in
ES Section 16 that successful implementation of the Transport Management Plan and
the application of the proposed mitigation and schemes will ensure that the
Development will have an insignificant impact on local transport infrastructure.
4.6
Medway Local Plan
4.6.1
On 21 September 2007, the Secretary of State "saved" various policies of the
Medway Local Plan to enable it to continue to constitute part of the "development
plan" for Medway Council. The policies referred to below which have all been "saved"
by the Secretary of State address strategy, built and natural environment, existing
employment areas, transportation and community facilities. Each of these, when
considered from an environmental perspective relative to the construction and
operation of the plant indicates that, subject to the mitigating measures proposed,
there is no conflict. Similarly, on the matter of land use, the ES explains that the
locational advantages of the Application site for purposes of the Development
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(Section 7) are also why Kingsnorth is recognised in the MLP as being suitable for
accommodating employment uses not readily accommodated elsewhere, including
those which are sui-generis, which characteristics are reflected in this Development.
Strategy
4.6.2
Policies S1, S2, S4, S6, S12, address development strategy, strategic principles,
landscape/urban design, planning obligations, Kingsnorth and Isle of Grain.
4.6.3
The development strategy prioritises investment in the urban areas with a focus on
the Medway riverside areas, while strategic economic development provision will be
made within the urban area and at the locations of Kingsnorth and Grain, with long
term protection afforded to areas of international, national or other strategic
importance for nature conservation and landscape (Policy S1). In the locations
referred to in Policy S1, the focus will be on improving environmental quality/design
standards and a sustainable approach to the location and mix of new development
(Policy S2), including a high quality built environment with landscape mitigation where
appropriate (Policy S4). Medway Council may require developers to enter into a legal
agreement to provide for new infrastructure and other facilities (Policy S6) when the
need arises directly from the development concerned. Section 6 confirms that, within
the Application site, Area 1 to the east of the existing Damhead Creek Power Station
will be used for the development of Damhead Creek 2; Area 2 to the northwest will be
used for the development of a 400 kV sub-station and Area 3 will be used during the
construction phase temporarily for car parking and storage for materials/equipment
and subsequently may also accommodate carbon capture equipment, although this
area could be available after completion of the Development or other temporary uses
subject to the grant of planning permission, as appropriate. The ES describes in
Section 3 the need for additional generating capacity in London and the South East
and the historic association of the Hoo Peninsula with power generation, while
Section 7 describes the locational advantages. It has been confirmed in Section 20
that Damhead Creek 2 will be similar in scale, design and layout to the existing
Damhead Creek Power Station, such that it will appear as an extension and that
development can occur without adversely impacting on nature conservation interests
(Section 13). Paragraph 4.3.20 in this Statement has referred to Circular 05/05 –
Planning Obligations which will be a matter for discussion with the LPA as
appropriate.
4.6.4
At Kingsnorth, general industry, storage/distribution uses and light industry will be
permitted and provision will be made for the relocation of businesses from urban
regeneration sites, including special industrial uses and others not in a use class,
subject to access and environmental considerations, which is consistent with the
proposal to use land for purposes of energy generation. The policy states that the
LPA will prepare a development brief in association with landowners; nature
conservation interests will be a consideration and development should not prejudice
the use of or access to wharves or rail sidings; contributions may be sought for the
improvement of offsite highways or the rail link (Policy S12). The reasons for the
selection of this site have been discussed in Section 7 indicating its locational
attraction and suitability for the development of energy generating facilities, in
particular accessibility to existing energy infrastructure.
Built/Natural Environment
4.6.5
Policies BNE1-6, BNE8, BNE20, BNE21, BNE22, BNE23, BNE24 address design,
amenity protection, noise standards, energy efficiency, lighting, landscape design,
security/personal safety, scheduled ancient monuments (SAM), archaeological sites,
environmental enhancement, contaminated land and air quality.
Design of
development should be appropriate in relation to the character, appearance and
functioning of the environment taking into account the amenity of occupants and
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those nearby (Policies BNE1, BNE2); development should not have a significant
adverse effect on nearby noise sensitive uses (noise level parameters are listed)
(Policy BNE3) and design should take account of energy efficiency (Policy BNE4).
External lighting should be the minimum necessary for security, safety and working
purposes (Policy BNE5); major development should provide for structural landscaping
to enhance the character of the locality (Policy BNE6); design/layout should maximise
personal safety and security of property (Policy BNE8). Development should not
adversely affect SAMs of other nationally important sites, or be detrimental to their
setting (Policy BNE20). An archaeological field evaluation (with a strategy for
mitigation) should be carried out before determining an application (Policy BNE21).
Development leading to protection/improvement of the appearance/environment of
existing/proposed areas of development (including areas adjacent to the River
Medway), will be permitted (Policy BNE22). Applications involving development of
contaminated land must be accompanied by a detailed site investigation
(Policy BNE23). Development resulting in airborne emissions should provide an
assessment to demonstrate the effects and measures for mitigation taking into
account the cumulative effects of other proposed or existing sources of air pollution
(BNE24).
4.6.6
The matters raised above have been discussed in particular in the following Sections
where these matters have demonstrated that there is no significant effect, namely:
Section
Topics
Findings
7
Site Selection and Alternatives
The choice of CGT technology delivers high efficiency
and savings in CO2 emissions which will be enhanced
with the implementation of CHP
10
Air Quality
There will be no significant cumulative operational
effects on air quality and contractor management can
address dust emissions.
11
Noise and Vibration
Noise levels from Damhead Creek2, cumulatively with
Kingsnorth units 5/6 are within 0.5dB of the noise level
of Kingsnorth units 5/6 operating alone; this difference
is not significant.
12
There will be no significant effect on local landscape
which is already dominated by the existing Kingsnorth
Power Station, the Damhead Creek Power Station and
other development; lighting, landscaping and design
will be addressed in the approval of details.
15
Geology, Hydrology and Land
Contamination
The assessment methodology, significance criteria and
findings explain that contaminated land is not a
significant risk and the potential impact can readily be
addressed; cumulative impact will be minimised and
insignificant.
17
Cultural Heritage
The impact on archaeological and paleoarcheaeological remains would be slight – moderate
adverse without mitigation, therefore it is proposed that
a watching brief is employed during construction.
4.6.7
Policies BNE33-39, BNE45, BNE46 address special landscape areas, areas of local
landscape importance, sites of international/national and strategic/local nature
conservation value, wildlife habitats/corridors, protected species and the
undeveloped/developed coast. Development within the North Kent Marshes special
landscape area will only be permitted if it conserves/enhances the natural beauty of
the area’s landscape, while in areas of local landscape importance, development
should not materially harm the landscape character/function of the area
(Policies BNE33, BNE34). The Medway Estuary and Marshes site will be given long
term protection consistent with its international/national nature conservation status
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(Policy BNE35), while other strategic and local nature conservation sites will be given
long term protection (Policy BNE36). Development that would cause a loss of
important wildlife habitats or features not protected by Policies BNE35/BNE36 will
also not be permitted unless there is an overriding need, no reasonable alternative
site exists and mitigation measures are addressed.
Wherever practicable,
development should make provision for wildlife habitats, however it will not be
permitted if statutorily protected species and/or their habitats will be harmed
(Policies BNE37, BNE38, BNE39). In/alongside the undeveloped coast, development
will only be permitted if a coastal location is essential and no suitable alternative
exists, however development will be permitted in/alongside the developed coast if it
improves the appearance/environment and the need for the location is justified
(Policies BNE45, BNE46). It has been established in Section 12 (Landscape ad
Visual) that the proposed Development will not have a significant effect on the local
landscape. Section 13 refers to the present 26 hectares of mitigation land on the site
and that a CEMP and a Works Method Statement will be put in place to avoid
disturbance and habitat degradation. It is confirmed that the recorded effects on very
important receptors, once mitigation measures have been implemented, will be not be
significant.
Existing Employment Areas
4.6.8
The MLP states that “The size and remoteness of the large industrial sites on the Isle
of Grain and at Kingsnorth makes them suitable for accommodating those
employment uses which may not be easily accommodated elsewhere, including land
extensive uses with low employment rates and those uses difficult to accommodate
within urban areas.” (MLP 4.2.7). This recognition of the characteristics of Kingsnorth
is consistent with the reasons in Section 7 for the selection of the Application site for
Damhead Creek 2.The employment land availability position as at March 2000, taking
account of the proposed plan allocations in the MLP and existing sites, is set out in
the plan at Figure 6aKingsnorth is identified as potentially providing an allocated site
of 66 hectares of land with 214,355m 2 of Class B1, B2, B8 potential employment
floorspace. It also stated that the Isle of Grain is likely to be developed for uses which
will not count towards meeting the Structure Plan guidelines. In its description of
Kingsnorth employment area, it is stated that “the designated existing site includes
the Kingsnorth Power Station and Kingsnorth Industrial Estate, which contains a
mixture of general industries. Further development on adjacent land will be permitted
for Class B1, B2, B8 uses under Policy S12”…“Specialist industrial uses will also be
permitted subject to acceptable environmental standards being achieved.”
(MLP 4.5.1(xiv)). The requirements for the Development of a CCGT generating plant
in this area are most readily fulfilled by the proposed Application site and which, by its
design can ensure that acceptable environmental standards can be met.
4.6.9
The MLP at Section 4.5 (existing employment areas) refers to its aim to retain existing
employment uses and to encourage investment by new development and extensions.
Policies ED1, ED5, ED7, ED8 concern existing employment areas, proposed
employment areas, special industrial areas and industrial uses not in a Use Class.
Kingsnorth is identified as a location where development will be permitted for
purposes of business (Class B1), general industry (Class B2) and storage and
distribution (Class B8) (Policy ED1). It is explained that in the undeveloped part of
Kingsnorth, a significant area has been safeguarded for landscaping and nature
conservation protection, leaving about 66 hectares available for development subject
to improvements to the local highway and rail networks and development not being
detrimental to the environmental importance of the Medway Estuary Marshes
(Policy ED5). Development of special industrial uses may also be permitted at
Kingsnorth, subject to the provisions of policies BNE2, BNE3, BNE23, BNE24
(Statement 4.5.16) and transport infrastructure contributions specified in Policies S12,
S13 (Policy ED7). The development of industrial uses not in a Use Class may be
June 2009
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SECTION 4
CONTEXT
permitted subject to Policy BNE2 and environmental impacts being acceptable
(Policy ED8). The EIA process has demonstrated that there are no significant
adverse effects arising from the development of the proposed Development.
Moreover, it has been established that there is a compelling need for the development
of additional generating capacity (Section 3) and that the site requirements for such
development can best be fulfilled by the utilisation of the Application site for purposes
of the proposed Development. It should further be noted that the SEP, discussed in
MLP Section 4.4 recognises the important role that infrastructure, including power
generation, has to play in the Kent-Thames Gateway.
Transportation
4.6.10
Policies T1, T2, T3, T4, T10, T12, T13, T14 concern access to the highway, provision
for pedestrians, cycle facilities, wharves, traffic management, vehicle parking
standards and travel. Proposals for development will be permitted, provided highway
capacity/risk and amenity issues can be addressed and that requirements for new
access will not be detrimental (Policies T1, T2). Development should provide
attractive and safe pedestrian access and maintain/improve pedestrian routes to the
site; similarly, there should be provision for cycle facilities for major trip attracting
development proposals (Policies T3, T4). Management of traffic will be addressed
with measures to improve safety for all, including cyclists/pedestrians while restraintbased maximum parking standards will be adopted; travel plans will be required for all
development needing a transport assessment (Policies T12, T13, T14). Wharves and
access to wharves, including Kingsnorth, are to be protected (Policy T10). Section 16
and the accompanying Transport Assessment have determined that implementation
of the Transport Management Plan and the application of the proposed mitigation and
schemes will ensure that the Development will have an insignificant impact on local
transport infrastructure.
Community Facilities
4.6.11
Policies CF10, CF12, CF13 concern overhead electricity supply lines, water supply
and tidal flood risk areas. The Council will seek to underground low voltage electricity
lines but only in exceptional circumstances will it seek undergrounding of high voltage
lines; however careful line routing should seek to protect the character of AONBs,
Special Landscape Areas, Nature Reserves, Ramsar sites and valued local
landscapes, particularly those which are designated (Policy CF10). Development
should not have a detrimental effect on the quality/yield of water supply,
replenishment/quality of ground water, aquifers or impact adversely on other nature
conservation habitats (Policy CF12). Within a tidal flood risk area, development
should not harm flood defences or fail to provide for means of escape for people in
the event of flooding (Policy CF13).
The proposed Development envisages
connecting directly into a new 400 kV sub-station and that there will be no
requirement for a further overhead transmission line to connect to the National Grid,
although the ultimate design of the connection will be the subject of a separate study
by NGC. Sections 14 and 15 respectively have confirmed that there are no
unacceptable affects associated with water provision, nor in relation to flood risk. The
proposed Development has been subject to a flood risk assessment which concludes
that it meets the requirements of an Exception Test in accordance with PPS25.
June 2009
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SECTION 5
SECTION 5
5
5.1
Operation of Damhead Creek 2
Power Generation
5.1.1
It is expected that for the majority of its life, Damhead Creek 2 will operate in various
running modes including full load (maximum continuous rating) and two shifting where
the plant operates at full load twice a day to meet peak demand. The plant will
occasionally be shut down for brief periods of essential maintenance and statutory
inspections. Damhead Creek 2 will have an annual availability of the order of
93 per cent with the remainder of the time dedicated to annual maintenance.
5.1.2
The operational life time of the development will be of the order of 35 years.
5.1.3
Damhead Creek 2 will consist of two combined cycle gas turbine units. Each unit will
comprise a gas turbine and a heat recovery steam generator (HRSG) which will serve
steam turbine equipment. The total electrical output of the Development will therefore
be 1000 MWe at typical site ambient conditions with a thermal input of approximately
1818 megawatts thermal (MWth).
5.1.4
The proposed plant layout is shown in Figure 5.1. The electricity generated will be
exported to the National Grid via a new substation that will be constructed on 3.6 ha
of land lying to the north west of the existing Damhead Creek CCGT Power Station.
This area of land is shown shaded green on Figure 2.1.
5.1.5
Damhead Creek 2 will generate in combined cycle mode with an overall electrical
Process Description
5.1.6
The gas turbines will burn natural gas in a combustion chamber from where the hot
combustion gases expand through the gas turbine, which in turn drives an electrical
generator to generate electricity. The hot exhaust gases still contain recoverable
energy and will therefore be used in a HRSG to generate steam. The high-pressure
steam produced will be used to drive steam turbine equipment to generate additional
electricity.
5.1.7
The spent steam leaving the steam turbine equipment will be condensed (via air
cooled condensers) and the resultant condensate returned to the HRSG for re-use.
The use of air cooled condensers means that there is no need for cooling towers or a
once-through cooling water system, thereby eliminating the environmental impacts
associated with such systems, which may have included a visible plume from a
cooling tower and would have required abstraction from, and discharge to, a local
water course.
5.1.8
The steam turbine system will comprise of the turbine equipment itself, a multi-cell air
cooled condenser and condensate extraction pumps and air extraction equipment.
5.1.9
Figure 5.2 shows a schematic representation of the combined cycle gas turbine
principle.
5.1.10
Each gas turbine will comprise an inlet air filter, an air compressor, combustion
chamber, power turbine and exhaust silencer. The gas turbines chosen for installation
at Damhead Creek 2 will be equipped with proven pollution control technology, which
will limit the production of oxides of nitrogen (NOx) to a maximum of 50 mg/Nm 3 when
gas turbine outputs are above 70 per cent in accordance with the limits set in the
Large Combustion Plant Directive (LCPD).
June 2009
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SECTION 5
5.1.11
The technology for gas firing, known as the dry low-NO x (DLN) system, limits
emissions of NOx to atmosphere. This technique represents BAT for limiting
emissions of NOx to atmosphere from gas turbines. Natural gas is a clean fuel and
does not produce the particulate emissions associated with burning coal;
consequently, post-combustion flue gas cleaning equipment is not required. State of
the art firing controls will be used, enabling combustion to be optimised for all
operating conditions.
5.1.12
The two gas turbines will be situated inside integral acoustic enclosures designed to
ensure that noise levels generated by the plant are within acceptable limits.
Additionally, the gas and steam turbine equipment and generators will all be enclosed
in steel framed buildings to further mitigate noise levels emanating from the Damhead
Creek 2 site.
5.1.13
The flue gases from each CCGT module will be discharged to a dedicated 75 m stack
the height of which has been determined by a computer dispersion modelling study.
There will be no bypass stacks installed.
5.1.14
Storage for chemicals will be provided in appropriately bunded and secure areas
within the existing Damhead Creek CCGT Power Station on site stores.
5.1.15
Fire water is currently stored in the existing Damhead Creek CCGT Power Station fire
water tank. This will be used for fire water usage for Damhead Creek 2 and fire
pumps, hose reels, fire hydrants and portable extinguishers will be installed to serve
Damhead Creek 2.
5.1.16
A deionised water storage tank will be provided on the Damhead Creek 2 site to
provide deionised water for the proposed two HRSG's on Damhead Creek 2. The
deionised water for this tank will be supplied from the existing Damhead Creek CCGT
Power Station’s water treatment plant.
5.1.17
The design of buildings, enclosures and equipment will also minimise regular and
long term maintenance. Sufficient spares will be held at Damhead Creek 2 to ensure
reliable operation of the plant. Materials and finishes will be selected to meet this
objective and to ensure that the appearance of Damhead Creek 2 does not
deteriorate over its operating lifetime (approximately 35 years). Materials and finishes
will be similar to those used on the existing Damhead Creek CCGT Power Station.
5.1.18
Transformers will be provided on site to allow the plant to receive electrical supplies
from the wider national grid. All transformers will be oil filled and each transformer will
be provided with a containment bund that will be capable of containing 110 per cent of
the oil content of the transformer in the event of a spillage. Pumps will drain these
sumps to an oil separator which in turn will discharge to the existing Damhead Creek
CCGT Power Station site drainage system. The sumps will be installed with high
level alarms to avoid overflow.
5.1.19
The remainder of Damhead Creek 2 will consist of air compressing equipment,
electrical switchgear and control equipment. Control facilities will be provided, as will
fire fighting services. Two emergency diesel generators will be installed, one on each
CCGT unit, to provide emergency back-up and enable Damhead Creek 2 to be shut
down in a safe manner in the event of loss of electricity. It is expected that these
engines will only ever be operated for testing purposes and only for very short
durations.
Operational Information
5.1.20
Damhead Creek 2 will burn natural gas only, which is an inherently clean fuel.
Natural gas will be brought to the Damhead Creek 2 site via the existing gas pipeline
connecting the existing Damhead Creek CCGT Power Station to the National
Transmission System. As the existing power station at Damhead Creek was built to
allow for expansion there will be no need to install a new gas pipeline with the existing
June 2009
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SECTION 5
line sufficient to provide all the gas needed by both plants. With the exception of
temperature and pressure regulation, the natural gas will not be treated on site and
accordingly natural gas will not be stored on the Damhead Creek 2 site. An indicative
Calorific Value of the natural gas is 46 600 kJ/kg.
5.1.21
The quality of the natural gas will be the same as that used in domestic properties
and will be supplied to a flanged terminal point most likely in the northern area of the
main site, at a pressure in the range of 30-70 bar(g). There will be gas pressure
reduction or compression facilities on the Damhead Creek 2 site to regulate the
pressure of the incoming gas supply to that required by the gas turbines.
5.1.22
Lubricating oils will be supplied to the gas and steam turbine equipment and
generator bearings and will also be supplied for the turbine control and hydraulic oil
systems. The lubricating oils will be stored on the existing Damhead Creek CCGT
Power Station site within steel tanks in an impermeable bund sized to contain 110 per
cent of the contents of each tank, in line with the Oil Storage Regulations2. The oils
are used to lubricate the gas and steam turbine equipment. Used lubricating oils will
also be stored on the existing Damhead Creek CCGT Power Station site for re-use or
will be disposed of off-site by an approved and licensed contractor in accordance with
applicable regulations.
5.1.23
Storage facilities will also be provided for the small quantities of sodium phosphate,
oxygen scavenger, ammonia and other chemicals used in boiler water dosing. All
such chemicals will be retained in suitable containment areas on the existing
Damhead Creek CCGT Power Station site. The boiler dosing chemicals and dosing
systems will be shielded from the atmosphere. Air discharged from the ammonia and
oxygen scavenger dosing and dilution tanks will pass through a device such as a
common water seal and an active carbon filter to avoid the uncontrolled release of
these chemicals to the atmosphere.
5.1.24
Miscellaneous materials such as oils, greases, cleaning substances and materials,
laboratory chemicals etc, will be stored in suitable storage conditions or containers on
the existing Damhead Creek CCGT Power Station site.
5.1.25
All storage facilities will be designed, situated and used in compliance with Control of
Substances Hazardous to Health (COSHH) Regulations.
5.1.26
Sewage effluent will be discharged into the existing sewage system on the existing
Damhead Creek CCGT Power Station site.
5.1.27
The compressed air system will be provided to compress and deliver air of a quantity
and quality suitable for all general, instrument and control purposes at all appropriate
points in Damhead Creek 2.
5.1.28
Plant performance will be continuously recorded to ensure correct and efficient
operation of Damhead Creek 2. Any significant deviations will be alarmed and
corrections carried out on occurrence. Records will be maintained of performance
and deviation.
5.1.29
Damhead Creek 2 will be designed with a view to automatic operation with a
minimum of operator intervention being necessary. Full facilities for interfacing
information, control and alarm systems will be installed so that Damhead Creek 2 can
be operated from the existing Damhead Creek CCGT Power Station central control
room via the distributed control system (DCS).
5.1.30
A feature of the gas turbine technology, on which Damhead Creek 2 is based, is that
waste transported to land fill off site would be minimal and would be restricted to the
following:
2
The Control of Pollution (Oil Storage) (England) Regulations 2001
June 2009
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SECTION 5
Used gas turbine air intake filters (typically replaced annually);
Separated oil/sludge from oil/water separators;
Used oil or chemical containers; and
General office waste.
5.1.31
These wastes would be returned to the original supplier where possible or removed
by an appropriate licensed contractor.
5.1.32
In the event of a gas turbine or HRSG trip, Damhead Creek 2 will shut down in an
orderly manner. In the event of a steam turbine trip the gas turbine will shut down in
an orderly manner.
5.1.33
Major plant maintenance shut downs will be planned on a long-term basis with
intermediate stoppages being infrequent and of short duration only.
Plant Dimensions
5.1.34
The indicative dimensions of the main items of plant are likely to be as shown within
Table 5.1. The exact dimensions cannot be identified until the detailed design stages
and so will be agreed with Medway Council prior to the commencement of
construction.
TABLE 5.1: PLANT DIMENSIONS (m)
Height (m)
Length (m)
Breadth (m)
HRSG Enclosure (2 No.)
40
30
30
Turbine Hall (2 No.)
28
80
30
Air Cooled Condensers (2 No.)
40
75
75
Height (m)
Diameter (m)
Deionised Water Tank
18
31
Raw Water Tank
18
27
Stack (2 No.)
75
5.9
5.1.35
The majority of the remaining plant and equipment will be housed in relatively low
buildings, of the order of 3 to 6 m in height. This is similar to the existing Damhead
Creek CCGT Power Station. The Damhead Creek 2 site will be surrounded by
securing fencing.
5.1.36
Damhead Creek 2 will be designed so as to be Carbon Capture Ready (CCR). An
area of land within ScottishPower’s control has been identified for future carbon
capture equipment. This is shown as the darker blue shaded region in Figure 2.1. As
per the requirements of DECC, a CCR Feasibility Study has been undertaken for
Damhead Creek 2. This study indicated that it is both technically and economically
feasible to retrofit Carbon Capture and Storage (CCS) technology to the Development
within its operating lifetime. Further details on this are provided in Section 19.
5.1.37
The gas turbines and HRSG will be positioned to allow Damhead Creek 2 to be easily
retrofitted should the potential for economic export of carbon dioxide (CO 2) become
available. The steam turbine equipment will be fitted with flanges to allow for steam
off take for any CC plant whilst the chimneys will be designed to allow for the
redirecting of the exhaust gases to any future CC plant.
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SECTION 5
Safety and Emergency Plans
5.1.38
The hazards associated with CCGTs have been studied over many years and a
considerable amount of design and procedural experience has been built up in this
area.
5.1.39
The design of Damhead Creek 2 will incorporate all the features needed to comply
with relevant safety regulations. The Health and Safety Executive (HSE) will also be
consulted with regard to safety issues associated with Damhead Creek 2.
5.1.40
ScottishPower will take into account and comply with all UK statutory regulations
including in particular, the Health and Safety at Work Act 1974, the Construction
(Design and Management) (CDM) Regulations 2007 and the Electricity at Work
Regulations 1989 and any other standards and Codes of Practice relevant to
Damhead Creek 2.
5.1.41
There will be no substances stored on Damhead Creek 2 or the existing Damhead
Creek CCGT Power Station site that will make the site notifiable to the HSE under the
Control of Major Accident Hazards (COMAH) Regulations 1999.
5.1.42
Fire detection and protection systems will be provided throughout the Damhead
Creek 2 site as is the case with the existing plant. These will include fixed water
protection systems, fire alarms and typical portable appliances.
5.1.43
A comprehensive fire protection system will be installed to cover all equipment on the
Damhead Creek 2 site that could constitute a fire risk. For the protection of
equipment within each gas turbine package, where water spray will cause damage, a
total flood CO2 system will be used. An automatic high velocity water spray system
for the protection of the turbine lubricating oil tank, coolers and associated pipework
will also be provided. Heat sensors will be used in conjunction with automatic spray
nozzles and smoke detectors. Non-combustible and fire resistant building materials
will be utilised. Continuous natural gas monitoring systems will be provided. Venting
systems will be designed to prevent explosion of air/gas accumulations. Ignition
sources will be protected from damage through their design. Testing of fire protection
systems will be carried out in accordance with the safety and emergency plan for the
existing Damhead Creek CCGT Power Station
5.1.44
Damhead Creek 2 will employ conventional protective features, including emergency
relief valves, shut down sequence interlocks, safety interlocks, fail safes, detection
and alarm systems, mechanical and electrical protective devices. There will be back
up systems and protective measures to deal with emergency situations such as
electrical power failure, water supply failure, compressed air failure, major equipment
failure and lightning strikes.
5.1.45
There will be no drains within the various storage bunds and all valves and couplings
will be within the bunded area. In the event of leakage or spillage from any oil storage
tank any oil will be contained within the bund surrounding the tank. Any oil found in
the bund will be removed for disposal to a licensed site.
5.1.46
Access to the Damhead Creek 2 site will be strictly controlled. Damhead Creek 2 site
security will be achieved by providing suitable fencing to the Damhead Creek 2 site
perimeter and cameras – as is the case with the existing Damhead Creek CCGT
Power Station.
5.1.47
An oil spill or chemical spill is recognised as being the principal environmental
emergency that could arise at Damhead Creek 2. Emergency response plans for the
existing Damhead Creek CCGT Power Station will be amended to incorporate
Damhead Creek 2 and will cover the following:
Emergency procedures for chemical tanks; and
Emergency procedures in the event of a spill of lubricating oil.
June 2009
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SECTION 5
5.1.48
In the surrounding area to the Damhead Creek 2 site, there are no installations
involving the storage or handling of hazardous substances or installations licensed or
permitted under the Pollution Prevention Control (PPC) Regulations 2000 /
Environmental Permit (EPR) Regulations 2007 that will be at risk from Damhead
Creek 2.
5.2
Construction of Damhead Creek 2
Environmental Management
5.2.1
The construction contractor will be required to prepare and implement a Construction
Environmental Management Plan (CEMP). The CEMP will identify the mitigating
measures and management procedures that will be put in place to adequately control
the environmental impacts of the construction stage, incorporating the relevant
Sections from this ES and any Consent conditions that the Secretary of State may
attach to any Section 36 Consent that he may grant for Damhead Creek 2.
Site Preparation
5.2.2
Further studies examining soil composition and contamination will be undertaken by
the construction contractor, building on the results of site investigations carried out
during the EIA process and as reported in this ES.
5.2.3
Excavations will be required to construct foundations, culverts, buried services and
basement structures. Excavation activities create the potential risk of disturbing and
hence releasing any existing contaminants within the ground into the surrounding
environment. However, a contaminated land survey has been conducted and the
Damhead Creek 2 site is found to be relatively uncontaminated. Nevertheless, as the
potential exists for any possible contamination from off-site to migrate onto the
Damhead Creek 2 site during construction, the contactor will conduct a further
contaminated soil survey and maintain a close watch for possible contamination
appearing during construction. In addition it will be necessary to undertake piling for
some of the foundations where the heavier plant equipment will be located.
5.2.4
The major activities during the construction phase of the project include, for the civil
works:
Site preparation works;
Construction of foundations; and
Construction of buildings.
5.2.5
Site preparation work will comprise the raising of the Damhead Creek 2 site,
earthworks, and the excavations for foundations.
Trenching, installation of
underground services and provision of temporary construction facilities including car
parking facilities, storage/laydown areas and services will then take place.
5.2.6
It is likely that, as was the case for the existing Damhead Creek CCGT Power Station
construction phase, piling will be required for the HRSG, gas turbine, steam turbine
equipment, and generator foundations due to the heavy loading and the tight
tolerance on settlement. The remaining foundations, for the turbine building, skids,
and pumps, will be spread footings and slabs of various thicknesses to suit the
structural needs.
5.2.7
Throughout the duration of the construction period, there will be a dedicated area set
aside for the laydown and storage of plant equipment. This area is shown in
Figure 2.1 by the darker blue shaded region. This area will be available for any
fabrication that may be necessary for construction works. An area on this part of the
Damhead Creek 2 site will also be set aside for car parking and office
accommodation. All necessary measures will be taken to return the laydown and car
parking areas to their previous state, on completion of the construction phase.
June 2009
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SECTION 5
5.2.8
The programme for the mechanical and electrical plant can be considered in terms of
the following activities:
1.
Steam turbine and HRSG manufacture;
2.
Gas turbine manufacture;
3.
Power plant erection;
4.
Power plant commissioning;
5.
Plant take-over;
6.
Power plant commercial operation; and
7.
Guarantee period.
5.2.9
Figure 5.3 shows the proposed construction programme should the two units be
constructed at the same time. Figure 5.4 shows the programme based on separate
construction of the two units. The construction period will be of 28 to 36 months
duration, including commissioning.
5.2.10
Initially and until the buildings are closed and capable of providing an ‘indoor working
environment’, construction work will only take place during the following times:
Monday to Saturday
07:00 – 19:00 hours
5.2.11
No work on any Sunday or Bank Holidays will be undertaken, unless such work is
associated with an emergency or does not cause existing ambient noise levels to be
exceeded.
5.2.12
Should a need arise, due to technical constraints or similar, with regard to carrying out
certain construction work outside the time indicated above, prior written approval from
Medway Council will be sought.
5.2.13
Commissioning of each CCGT unit will take of the order of 16 weeks and will be
progressive from final erection checks, pre-commissioning and setting to work of
individual component parts through to the overall testing to prove the technical
acceptance of Damhead Creek 2. Tests on completion will demonstrate the fitness
for purpose of Damhead Creek 2 prior to commercial operation. Performance tests
will demonstrate that Damhead Creek 2 complies with the performance guarantees.
Reliability will be demonstrated by operating Damhead Creek 2 under commercial
conditions for a period without major repair to any item of plant or equipment.
5.2.14
occur over two phases with the first starting in 2016 and the second in 2019. There is
however the possibility of the connection offer being amended by NGC to allow for
connection of Damhead Creek 2 in one stage in 2016 depending on a variety of
factors including the construction schedule of various other UK power projects. If this
scenario were to happen, then construction of Damhead Creek 2 would commence in
2013.
5.2.15
Should the entire of Damhead Creek 2 be built in one stage, construction would take
between 28 and 36 months with the construction workforce peaking at around 1000
personnel. Should a two stages construction phase be pursued this would increase
the construction period by around three years, but reduce the construction workforce
to a peak of around 600 and would also reduce the traffic flows associated with the
project.
June 2009
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SECTION 5
Decommissioning
5.2.16
At the end of the useful life of Damhead Creek 2 (around 35 years from
commencement of operations), Damhead Creek 2 will be decommissioned in
accordance with legislative guidelines current at that time. Alternatively, if market
conditions and/or electricity supply constraints at that time indicate that it would be
appropriate to extend the life of Damhead Creek 2, then decommissioning may be
deferred to a later date. In order to ensure continuing adequate plant conditions and
environmental performance, Damhead Creek 2 would be re-engineered and repermitted as required, dependent on the legislative requirements at that time.
5.2.17
Independently validated plant closure/demolition methodologies have been developed
for power plants that are at the end of their useful life. The methodology covers
demolition of the plant and buildings and removal of any contaminated and hazardous
material from the site. When demolishing the power plant, it will be a matter of policy
to ensure that the site is left with no environmental or safety risks.
5.2.18
Decommissioning will be in accordance with the requirement of Damhead Creek 2's
EPR Permit including the site closure plan which has to be included as part of
Damhead Creek 2’s EPR Application (which will be submitted to the EA at the same
time or shortly afterwards the application for the Section 36 Consent is submitted to
the Secretary of State).
5.2.19
In order to facilitate decommissioning, much of the plant on site will be made of
materials suitable for recycling. In addition, a large proportion of the buildings will be
constructed of pre-fabricated steel and will therefore also be of interest to scrap metal
merchants. After the removal of the main items of plant and steel buildings, the
remaining buildings will be demolished to ground level. All underground structures
will either be removed or made safe. All deconstruction material to be removed offsite
will be sent to a licensed waste management facility.
5.2.20
The decommissioning phase is likely to take place over several months.
5.2.21
The results of the pre-construction contaminated land survey will be used as a basis
for a further contaminated land survey to be performed when Damhead Creek 2 is
closed to assess whether or not any contamination of the Damhead Creek 2 site has
taken place during the lifetime of Damhead Creek 2. The Damhead Creek 2 site will
be returned to a condition suitable for reuse.
5.2.22
A full environmental departure audit will be carried out prior to decommissioning. This
will examine, in detail, all potential environmental risks existing at the Damhead Creek
2 site and make comprehensive recommendations for remedial action to remove such
risks. Following completion of the demolition, a final audit will be carried out to ensure
that all remedial work has been completed. The audit reports will be made available
to future users of the Damhead Creek 2 site.
5.2.23
Prior to ScottishPower decommissioning Damhead Creek 2, the Environment Agency
will be notified as to the date of the closure and the results of the departure audit
submitted.
5.2.24
During decommissioning all reasonable measures required to prevent any future
pollution of the Damhead Creek 2 site will be carried out. This will include measures
such as:
The emptying/cleaning and removal of storage tanks; and
The removal from site of all materials/liquids liable to cause contamination.
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SECTION 5
5.2.25
The surface water drainage system for the plant will continue to operate throughout
the decommissioning phase. Any areas where oil spillage could occur will continue to
drain to an oil interceptor, which will continue to be maintained.
5.2.26
Decommissioning of Damhead Creek 2 may or may not coincide with that of the
existing Damhead Creek CCGT Power Station.
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SECTION 6
DESCRIPTION OF DEVELOPMENT SITE AND
ITS SURROUNDINGS
SECTION 6
DESCRIPTION OF DEVELOPMENT SITE
AND ITS SURROUNDINGS
6
DESCRIPTION OF DEVELOPMENT SITE AND ITS SURROUNDINGS
6.1
Development Site Description
6.1.1
The location of the Damhead Creek 2 site is shown in Figure 1.1. An aerial map
showing the existing Damhead Creek CCGT Power Station and the Damhead Creek
2 site can be seen in Figure 6.1, and an aerial photograph of the existing Damhead
Creek CCGT Power Station can be seen in Figure 6.2.
6.1.2
The Ordnance Survey (OS) Grid Reference of the centre of the Damhead Creek 2
site is approximately 580860, 172704. The Damhead Creek 2 site is within the
jurisdiction of Medway Council, in the County of Kent.
6.1.3
The Damhead Creek 2 site is divided into three main areas, which are shown on
Figure 2.1. These areas comprise:
Area 1.
6.2 ha of land lying mainly to the east of the existing Damhead Creek CCGT
Power Station. This is the location of Damhead Creek 2 and is shown
shaded red on Figure 2.1;
Area 2.
Power Station. This is the location of the proposed 400 kV substation and is
shown shaded green on Figure 2.1; and
Area 3.
construction phase of the Development. It is intended that this area will also
be set aside for the installation of Carbon Capture and Storage (CCS)
equipment in the future, and thus will be reserved as such. The remainder
of the area would be dedicated to ecological mitigation including additional
ponds and habitat enhancement. All land in this area has previously been
used to dispose of the fly ash from the nearby Kingsnorth Power Station. It
is surrounded by ecological mitigation land associated with the Damhead
Creek Power Generation Development, and currently contains a number of
small ponds. This area is shaded darker blue on Figure 2.1.
6.1.4
Figure 2.1 also shows that the Damhead Creek 2 site adjoins an extensive area of
ecological mitigation land (some 26 ha). This area is highlighted in yellow.
6.1.5
Area 1 of the Damhead Creek 2 site is on low lying undulating ground sloping to the
south east, and currently consists of mainly unmanaged grassland and hardstanding.
Area 2 is for the most part hardstanding and is currently unused. Area 3 consists of
an area of land previously used to dispose of fly ash from the Kingsnorth Power
Station and is surrounded by ecological mitigation land. This area has been
established and maintained as part of the Damhead Creek Power Generation
Development. All areas of land that it is proposed will be used for the purposes of
Damhead Creek 2 are considered to be poor quality and are not used for agricultural
purposes.
6.1.6
Historically the area was mainly marsh land, which was drained in the late 1800’s and
the area was used for agricultural purposes. For a short period between 1912 and
1920 the site housed a naval airship installation. In about 1938 construction started
on an oil refinery about 500 m to the north-west of the Damhead Creek 2 site. This
was steadily extended and came within about 100 m of the Damhead Creek 2 site
before production ceased. The oil refinery was demolished in the 1990s and replaced
with the present Kingsnorth Industrial Estate. The Kingsnorth Power Station was
constructed to the south of the Damhead Creek 2 site in the early 1970s with the
June 2009
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SECTION 6
existing Damhead Creek CCGT Power Station being constructed between 1999 and
2001.
6.1.7
All areas of the Damhead Creek 2 site are underlain by the London Clay, which is
covered with superficial alluvium deposits. There are no significant aquifers that are
used for water supply beneath the Damhead Creek 2 site. A contaminated land
survey has shown that the Damhead Creek 2 site is not the subject of any significant
contamination.
6.1.8
There are no environmental designated sites or scheduled monuments within the
Damhead Creek 2 site boundary though there are a number of designated ecology
sites in the area of the site that are discussed in Section 13.
6.1.9
Access to the Damhead Creek 2 site will be achieved via a dedicated access road
that leads around Kingsnorth Industrial Estate, immediately north west of the
Damhead Creek 2 site, and connects with Stoke Road. Roper’s Lane connects
Stoke Road to the A228 approximately 1.1 km north east of the junction for
Hoo St. Werburgh and around 1.2 km south of High Halstow which in turn connects to
the M2.
6.2
Development Site Surroundings
6.2.1
The Damhead Creek 2 site lies approximately 3 km south-east of the A228, which
connects the A2/M2 with the Isle of Grain, and 9 km north-east of the city of
Rochester. It is situated on the southern edge of the tongue of land between the
Thames and Medway estuaries known as the Hoo Peninsula. The village of Hoo
St Werburgh, the nearest settlement, lies 3 km to the west between the coast and
A228.
6.2.2
Creek 2 site is filled with pulverized fuel ash and is designated as a future
development area under the Medway Local Plan. Much of this land is now
encompassed by two outline planning applications to Medway Council for a business
distribution and storage facility proposed by Goodman Developments Limited that will
include up to eight storage warehouses and associated infrastructure (Kingsnorth
Business Park).
6.2.3
(some 26 ha), which is also shown on Figure 2.1 as the light blue area. This area has
been established and maintained as part of the Damhead Creek Power Generation
Development. This mitigation land is owned by ScottishPower and is managed to
mitigate the power generation equipment and infrastructure within the existing
Damhead Creek CCGT Power Station and the 6.2 ha of land of Damhead Creek 2.
This mitigation land borders the land that is the subject of the two outline planning
applications submitted by Goodman Developments Limited as discussed in Section 2.
6.2.4
The south and eastern margins of the Damhead Creek 2 site are bounded by
drainage ditches. These drainage ditches drain naturally through the strata and into
the Damhead Creek. The Damhead Creek itself flows north east and east, into East
Hoo Creek, which subsequently flows into the River Medway, approximately 2 km
east of the Damhead Creek 2 site boundary.
6.2.5
The existing Damhead Creek CCGT Power Station is located immediately to the west
of the Damhead Creek 2 site, and is a natural gas-fired CCGT plant and comprises
two gas turbines and their associated waste heat recovery boilers and one steam
turbine. The total plant output is 792 MWe at site rated conditions. The main cooling
system for the steam cycle utilises air condensers.
June 2009
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SECTION 6
6.2.6
The existing Kingsnorth Units 1 – 4 are located to the south of the Damhead Creek 2
site and consists of four 500 MW units, each with a boiler and steam turbine. It is
cooled by a once-through cooling system with the water abstracted from the River
Medway and discharged to Damhead Creek.
6.2.7
The immediate area is dominated by the bulk of Kingsnorth Units 1 – 4 with the boiler
house rising to a height of around 50 m and the associated chimney to 198 m.
6.2.8
To the east, the landscape is dominated by the oil-fired Isle of Grain Power Station,
which also has a boiler house around 50 m in height and a chimney 244 m in height.
6.2.9
In addition to these large power stations there are a number of high voltage overhead
transmission lines that connect the Isle of Grain Power Station, Medway Power
Station, the existing Damhead Creek GGCT Power Station and Kingsnorth Power
Station to the National Grid Network.
6.2.10
The Damhead Creek 2 site is located immediately adjacent to the Medway Estuary
and Marshes Site of Special Scientific Interest, Special Protection Area (SPA) and
Ramsar site.
6.3
Other Developments with Potential Cumulative Impacts
6.3.1
In addition to considering the potential impacts associated with the Development, the
EIA has considered the potential for cumulative impacts with other developments in
the vicinity of Damhead Creek 2.
6.3.2
Other projects in the vicinity of Damhead Creek 2 which have been identified by
Medway Council as potentially generating cumulative impacts are the:
Kingsnorth Power Station (Units 5 and 6);
Kingsnorth Business Park;
Grain CCGT Power Station;
LNG Facility at National Grid, Isle of Grain;
Wind Farm at Grain;
Wind Farm at Lappel Bank;
Land Reclamation Project at Garrison Point, Sheerness;
Medway Approach Channel Deepening;
Thamesport Quay Extension; and
New settlement at Chattenden.
Developments to be Included in Cumulative Impacts Assessment
6.3.3
Of the projects listed above, two developments are identified to have the potential to
generate cumulative impacts when considered in conjunction with the development of
Damhead Creek 2.
Kingsnorth Power Station (Units 5 and 6)
6.3.4
The land immediately to the south of the Damhead Creek 2 site is currently the
subject of an application for Section 36 Consent under the Electricity Act 1989 by
E.ON UK Plc for construction of a 1600 MW Supercritical Coal-Fired Power Station.
The development (as proposed) would include, at its upper parameters, two 110 m
high boiler houses each with a dedicated c. 198 m high stack (therefore two stacks)
and associated infrastructure.
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SECTION 6
6.3.5
The plant would be direct cooled using cooling water from the River Medway, which
would then be released into the Damhead Creek before returning to the Medway.
The project was due to commence construction in March 2008 with firing of the first
unit expected in 2012. These dates are unlikely to be achieved following delays to
the planning determination of the project.
6.3.6
The project has recently been approved by Medway Council but still requires approval
from the Secretary of State before any Section 36 Consent and thereby construction
works could be started. It is not known when the Kingsnorth Section 36 Consent
determination will be made or if a Public Inquiry (as requested by Medway Council)
will be instigated by the Secretary of State.
Kingsnorth Business Park
6.3.7
The land immediately to the east of the Damhead Creek 2 site, and part of the
Damhead Creek 2 site itself, is subject to two outline planning applications to Medway
Council for the construction of storage warehouses and associated infrastructure by
Goodman Developments Limited.
6.3.8
The construction of the road and site infrastructure was identified in the Kingsnorth
Business Park ES as being expected to commence in 2008, subject to the granting of
planning permission, with completion anticipated in 2009. However, the ES noted that
warehouse construction programme would be driven by market demand for the units,
with an anticipated completion date of 2014. As works have not yet started, this
schedule clearly cannot be adhered to with the actual construction schedule still
unclear at the time of writing this ES.
Summary
6.3.9
Table 6.1 provides details of the above developments and the potential cumulative
impacts in both the construction and operational phases.
6.3.10
The potential cumulative impacts have included for the possibility that all three
projects (i.e. including Damhead Creek 2) may be in some stage of construction at the
same time (should all three receive planning permission), and similarly that the
operational lives would overlap for many years.
TABLE 6.1: PREDICTED CUMULATIVE IMPACTS
Development
Current Status
Kingsnorth Power Station
Awaiting Section 36
Consent determination
from the Secretary of
State at DECC
Resolution for Approval
made
Kingsnorth Business Park
Potential Cumulative Impacts
Construction
Operational
Air quality, noise, visual,
Air quality, noise, and
and construction traffic
visual impacts.
impacts.
Air quality, noise, visual,
ecological, and
construction traffic
impacts.
Visual and ecological
impacts.
Developments not to be Included in Cumulative Impacts Assessment
6.3.11
The other projects in the area are, on closer review, considered likely to have a
negligible cumulative impact when considered in conjunction with the development of
Damhead Creek 2. The justifications for these considerations are summarised below.
Grain CCGT Power Station / LNG Facility at National Grid, Isle of Grain
6.3.12
These facilities are considered to be too far away from the Development
(approximately 8 km and 7 km respectively) to have any significant impact during the
operational phase of the Development, even in terms of air quality. This is due to the
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SECTION 6
fact that plumes from CCGT Power Stations generally ground within the first few
kilometres of the stack.
6.3.13
Traffic and construction impacts will not be relevant as Damhead Creek 2 will not start
construction until after the work on the other two facilities is complete.
Wind Farms at Grain and Lappel Bank
6.3.14
As with the above facilities, these wind farms are also considered too far away
(approximately 6 km and 10 km respectively) to have any impact when considered in
conjunction with Damhead Creek 2.
Land Reclamation Project at Garrison Point, Sheerness / Medway Approach Channel
Deepening
6.3.15
These are also considered to be far away (approximately 10 km and 7.5 km
respectively) to have any bearing on the Development.
Thamesport Quay Extension / New Settlement at Chattenden
6.3.16
These are also considered too far away (approximately 12 km and 6 km respectively)
and too small respectively to affect the proposed Development.
June 2009
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SECTION 7
SECTION 7
7
7.1
Site Selection
7.1.1
Damhead Creek 2 will be constructed on land adjacent to the existing Damhead
Creek CCGT Power Station.
7.1.2
There are many advantages to the proposed site that make it an ideal location for
power generation. These include, amongst others:
The close proximity of the 400 kV National Grid transmission system;
Transport infrastructure that will accommodate construction traffic;
Availability of sufficient land;
Availability of technical support from the existing Damhead Creek CCGT Power
Station;
Availability of natural gas without any requirement for a new pipeline;
Reduced visual impact due to the industrial nature of the immediate area;
Proximity of the Damhead Creek 2 site to land set aside in the local plan as
‘Major Employment Area’ thereby raising the potential for the demand and
therefore provision of low grade heat, thus improving the overall efficiency of the
plant subject to technical and commercial considerations.
7.1.3
It is therefore considered that the proposed site is suitable for the intended use of
power generation.
7.2
Alternatives
Introduction
7.2.1
The EIA Regulations require that the ES should include an outline of the main
alternatives that have been considered and an indication of the main reasons for
choosing the application site.
7.2.2
In the case of Damhead Creek 2, the alternatives that have been considered are:
Alternative development sites; and
Alternative technologies for electricity generation.
7.2.3
These alternatives are described below. Alternative layouts are not addressed in
detail, as the ultimate layout of the project can only be determined once a contractor
has been appointed for the final design and construction of the Development.
However discussion is included regarding the layout which has formed the basis of
the ES and is considered to represent the most likely layout for the Development.
Alternative Development Sites
7.2.4
ScottishPower has considered six sites in the south east of England for possible
development of a gas-fired CCGT Power Station.
7.2.5
The south east was chosen as the geographical area for the reasons detailed in
Section 3. In brief, these include the deficit of generation plants in the area coupled
with a high and rising demand for more electricity in London and the south east.
Therefore, due to the transmission losses that occur when electricity is transmitted
through the National Grid, locating the generation plant closer to the demand both
reduces the losses and has a positive effect on the environment by removing the
need for more overhead power cables.
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SECTION 7
7.2.6
The actual locations considered by ScottishPower are not stated due to commercial
and landowner sensitivities.
7.2.7
The six sites were ranked against the following major aspects:
Proximity to 400 kV electrical interconnection;
Proximity to natural gas supply;
Availability of water for possible cooling purposes;
Suitable transport connections;
Suitable site access;
Availability of labour;
Sufficient area of land available;
Suitable ground conditions; and
Opportunities for utilisation of waste heat / provision of Combined Heat and
Power (CHP).
7.2.8
Insert 7.1 presents the results of the Site Selection Study. The scoring ranges from 1
to 10, with 1 being the lowest.
INSERT 7.1: SITE SCORING RESULTING FROM THE SITE SELECTION STUDY
7.2.9
Insert 7.1 indicates that the Damhead Creek 2 site was the most highly scored of the
six sites, when all the major aspects were considered.
7.2.10
Particular benefits for the resulting site selection include:
The proximity to both the existing Damhead Creek CCGT Power Station and
Kingsnorth Power Station (Units 1 – 4)
The location in an area zoned for heavy industry
The location in an area of high electricity demand;
June 2009
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SECTION 7
The benefit an existing gas supply which will negate the need for construction of
a new gas pipeline.
7.2.11
A new substation will be required. However this will not likely require the installation
of additional overhead power lines.
7.2.12
Since the site selection study, three of the sites considered have subsequently been
developed for other industrial uses.
Alternative Power Generation Technologies
7.2.13
There are a number of options available for the generation of 1000 MWe in the UK.
These include:
Sustainable energy, such as biomass or waste to energy;
Renewable energy, such as wind or photovoltaics;
Nuclear power; or
Fossil fuelled power plant.
Sustainable Energy
7.2.14
There are a small number of biomass plants in the UK, which utilise wood, straw or
chicken litter as fuels. Until recently the largest of these was the Thetford 38.5 MWe
Chicken Litter Burning Plant in Norfolk, which burns in the order of 200 000 tonnes
per annum. A new 40 MWe Biomass Plant near Lockerbie in Scotland was
commissioned in December 2007 with two larger, 300 MWe Biomass Plants proposed
at Teesport and Port Talbot. Due to constraints with regards to fuel availability and
transport, it would not be feasible to install such a plant in the Damhead Creek area.
In addition, there would also be significant traffic movements associated with the
delivery of the biomass fuel.
7.2.15
The largest waste to energy plant in the UK is Edmonton Waste to Energy facility in
North London. This currently provides 30 MWe. However proposals exist to double
its capacity. The facility at Edmonton currently incinerates 75 tonnes/hour or
1800 tonnes/day of municipal waste. This is equivalent to that resulting from a
population of approximately 260 000. Therefore, in order to provide in the order of
1000 MWe, the plant would need to incinerate the waste from a population of over
8.9 million. This is clearly impracticable in terms of the collection and transport of
such quantities of waste. In addition due to their significant expense, waste to energy
plants are generally regarded as a waste management option rather than a power
generation option.
Renewable Energy
7.2.16
In order to provide 1000 MWe from wind turbines, approximately 1000 tall turbines
would be required to provide the same nominal annual power output. This estimate
incorporates the UK’s average capacity factor for wind turbines of 30 per cent (British
Wind Energy Association standard emissions saving methodology), which means that
over a year a turbine could produce 30 per cent of the amount of electricity it could
theoretically produce if it was working continuously at full capacity all through the
year.
7.2.17
Therefore, to produce the equivalent 1000 MWe that Damhead Creek 2 could
produce, around 3000 MWe of wind power would be required to be installed. This
would require up to 300 000 hectares of land. Although, 99 per cent of this land could
still be used for productive farming, the tall wind turbines (each of the order of 120 m
in height) would have a visual impact over such a vast area.
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SECTION 7
7.2.18
In addition, complications arise when wind turbines are located in remote locations
where the wind resource is abundant, as this introduces subsequent transmission
issues.
7.2.19
For these reasons wind turbines are not considered a practicable option to provide a
similar power output as the proposed Development.
7.2.20
Solar photovoltaic panels convert light energy directly into direct current (DC) suitable
for charging a battery. Due to their small scale they are not considered feasible for
providing up to 1000 MWe in the UK.
Nuclear Power
7.2.21
Nuclear power has not been considered as the consenting regime for new nuclear
power plants has identified sites suitable for such plant in other areas of the UK.
Fossil Fuelled Power Plant
7.2.22
A 1000 MWe coal fired power plant could be constructed to generate the electricity.
The coal fired power plant could be either:
Conventional pulverised fuel fired with appropriate pollution control techniques.
These would include flue gas desulphurisation (FGD) and selective catalytic
reduction (SCR), which would control sulphur dioxide and NOx respectively to
meet LCPD limits and Environment Agency benchmarks;
Fluidised bed technology with in bed capture of sulphur dioxide and appropriate
techniques for NOx control, such as SCR; or
Coal gasification coupled with a CCGT plant.
7.2.23
The coal fired plant could operate at sub-critical steam conditions similar to all existing
coal fired plants in the UK or could operate more efficiently using supercritical steam
conditions. Such supercritical conditions are likely to be applied on all new coal fired
plant in the UK.
7.2.24
Coal gasification is considered to have considerably high commercial risk associated
with its development, as it is relatively new technology and as yet, unproven in the
long-term.
7.2.25
Development of a 1000 MW oil fired plant could take the form of either a conventional
boiler / steam turbine power plant with appropriate control of sulphur dioxide and NO x
to meet LCPD limits and Environment Agency guidelines, or oil gasification coupled
with a CCGT plant.
7.2.26
Given the proportionally high cost of oil, it is considered uneconomic to develop such
a large oil fired power station.
Summary
7.2.27
Table 7.1 shows a comparison of the atmospheric emissions from the power plants
described above in comparison to a gas fired CCGT power plant similar to that
proposed for Damhead Creek 2. All atmospheric emissions are scaled to those
resulting from the generation of 1000 MWe.
7.2.28
Table 7.1 shows that Damhead Creek 2 would result in significantly lower emissions
on a g/MWh basis for almost air pollutants considered, including carbon dioxide
(CO2). The exceptions are for NOx and CO, although the level of NOx reported is
higher than that reported for coal gasification with CCGT power plant, but is lower
than the other three plants.
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SECTION 7
TABLE 7.1: COMPARISON OF ATMOSPHERIC EMISSIONS OF NEW POWER
PLANTS
Parameter
NOX
Units
Proposed
CCGT
Conventional
Oil Fired
Power Plant
with FGD
and SCR
Conventional
Coal Fired
Power Plant
with FGD
and SCR
Supercritical
Coal Fired
Power Plant
with SCR
Coal
Gasification
with CCGT
Power Plant
50
200
200
200
50
311
538
708
585
213
Emission Limit
3
(mg/Nm )
Negligible
200
200
200
1
g/MWh
Negligible
538
708
585
4
Emission Limit
3
(mg/Nm )
Negligible
30
30
30
1
g/MWh
Negligible
81
106
88
4
50
100
100
100
50
311
269
354
292
213
15
3
6
6
15
389
717
913
754
719
Emission Limit
3
(mg/Nm )
g/MWh
SO2
Particulates
CO
Emission Limit
3
(mg/Nm )
g/MWh
O2 content of
Flue Gases
%
CO2
kg/MWh
7.2.29
Assuming 100 per cent operation at full load over the course of a year, Damhead
Creek 2 would emit approximately 3.4 million tonnes of CO2. In comparison, a new
supercritical coal fired power plant would emit approximately 6.6 million tonnes of CO2
and an existing sub-critical coal fired power plant would emit approximately 8 million
tonnes of CO2 when generating an equivalent electrical capacity. Therefore, this
would equate to a total saving of the order of 4.6 million tonnes of CO2 if the plant
were to displace an equivalent existing sub-critical coal fired power station.
7.2.30
As such, the operation of Damhead Creek 2 could make a significant contribution to
the UK Government’s Policy of reducing CO2 emission levels whilst maintaining a
secure supply of electricity.
7.2.31
As a participant in the European Union Emissions Trading Scheme (EU ETS), the UK
was allocated an allowance of 245 million tonnes CO2 per annum for Phase I of the
scheme which ran from 1 January 2005 to 31 December 2007. This allowance was
reduced to 230 million tonnes CO2 per annum in Phase II, which is now in operation
and will run from 1 January 2008 to 31 December 2012. Damhead Creek 2 is not
expected to commence operation until 2016 at the earliest, and therefore will enter
any future third phase of the EU ETS, the details of which are currently unknown.
7.2.32
Damhead Creek 2 will, due to its greater efficiency, help the UK to conserve its
national allocation of CO2 allowances due to its much lower CO2 emissions compared
to those from similar sized coal and oil fired power plant. This will have a beneficial
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SECTION 7
effect on the economy of the UK, which is expected to be further impacted upon by
the price of carbon allocations in the future.
7.2.33
Table 7.2 compares other impacts of the fossil fuel generation sources.
TABLE 7.2: A COMPARISON OF THE IMPACTS OF TYPES OF NEW 1000 MW
GENERATING PLANT
Parameter
Units
Proposed
CCGT
Conventional
Oil Fired
Power Plant
with FGD
and SCR
Conventional
Coal Fired
Power Plant
with FGD
and SCR
Supercritical
Coal Fired
Power Plant
with SCR
Coal
Gasification
with CCGT
Power Plant
%
55
38
38
46
48
Ash*
kt/a
Nil
Nil
340
281
269
Gypsum*
kt/a
Nil
90
137
113
Nil
Miscellaneous
t/a
140
1800
1800
1800
1800
m
55+
190
190
190
55+
Efficiency
Solid Waste
Stack Height**
Water Treatment Plant
Effluent ‡
m /h
3
6
23
23
113*
21
FGD Effluent
m /h
3
Nil
32
32
32
Nil
Boiler Blowdown
m /h
3
35
90
90
Nil
105
Total Effluent
m /h
3
41
145
145
145
126
£/kW
Installed
Capacity
500
950
1050
1080
1500
Cost
*
Gypsum and ash can be sold as useful by-product if of sufficient quality and a market is available, otherwise these
must be disposed of to landfill.
**
stack height dependant on location of plant and its surroundings
‡
Including effluent from condensate polishing for supercritical plant.
7.2.34
In addition to the other benefits shown in Table 7.2, CCGT plants have a much
smaller footprint than conventional thermal power plant.
7.2.35
The capital cost of all the above coal and oil fired options are two or more times the
base case option (i.e. CCGT).
7.2.36
A gas-fired CCGT plant will, therefore, offer BAT for the proposed Development.
Alternative Cooling Technologies
7.2.37
CCGT plants utilise the heat from the exhaust gases leaving the gas turbine to
generate steam in a waste HRSG. This steam is then used in steam turbine
equipment to generate further electricity. The steam leaving the steam turbine
equipment is condensed by either water or air, producing condensate that is then
reused in the HRSG.
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SECTION 7
7.2.38
Potential cooling techniques available include:
Once through cooling (direct river or sea water cooling);
Evaporative cooling towers;
Hybrid cooling towers; and
Air cooled condensers (ACC).
Once through Cooling
7.2.39
As the Development site is close to the River Medway, there is a potential for a oncethrough cooling system using the saline water from the river. However, as the
Damhead Creek 2 site has no easy access to the river, the only possible route would
involve a long tunnel across land owned by various other parties. In addition, if this
option were to be employed, an intake structure (most likely located in the River
Medway) and pump house would also be required. However, taking into account the
costs and difficulties associated with this possibility and the potential environmental
impacts, this cooling system is not considered viable for the Development.
Evaporative Cooling Towers / Hybrid Cooling Towers
7.2.40
Another potential cooling system would be to employ cooling towers, which could be
either evaporative cooling towers or hybrid cooling towers. However, these require a
significant quantity of make-up water to replace the water lost by evaporation. There
are two potential sources for make-up water which are the River Medway or the
domestic water supply. As with a once-through cooling system, access issues rule
out the use of water from the River Medway, whilst the use of a domestic water
supply in cooling towers is not considered a viable use of a supply that is already
under pressure.
Summary
7.2.41
Therefore, due to the lack of a suitable viable cooling water source at the Damhead
Creek 2 site, only ACCs would be able to provide a practical cooling system for the
Development. This type of cooling system was also previously selected for the
7.2.42
The performance of ACCs (as for cooling towers), is dependent on ambient
temperature and is also sensitive to prevailing wind direction, gusty conditions and the
height and position of buildings and other structures in the vicinity. Damhead Creek 2
will be designed to minimise the impact of these sensitivities and ensure optimum
operational performance. The preferred design for ACC units position the heat
exchangers above the fan units, at approximately 40 m above the ground surface.
Alternative Layouts
7.2.43
Due to EU procurement laws, the contractor who will design and construct the
proposed plant must be appointed through a competitive procurement process that
will not be undertaken until the Section 36 Consent is granted. It is not until this stage
that the detailed design of the layout for Damhead Creek 2 would be optimised. For
this reason, it is not possible at this stage to provide definitive layout plans for
Damhead Creek 2.
7.2.44
The layout which has been assumed for the purposes of the EIA and the associated
studies has been developed through preliminary engineering studies. It is considered
to represent the most likely layout for Damhead Creek 2. The likely Damhead Creek
2 layout has been designed taking the following factors into consideration:
Road access;
Connection to transmission network;
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Provisions to minimise noise and visual impact;
Compliance with regulatory requirements;
Plant and personnel safety;
Provision for future development of additional emission abatement equipment;
and
Technical requirements.
7.2.45
The ultimate design will be the subject of a planning condition that will require
ScottishPower to agree the final design and appearance of Damhead Creek 2 with
Medway Council prior to construction commencing.
7.2.46
Due to the triangular shape of Area 1, which is identified as the land available for the
development of Damhead Creek 2 it is likely that one gas turbine, HRSG and steam
turbine unit would be aligned north / south adjacent to existing Damhead Creek
CCGT Power Station on the western part of Area 1, and the second gas turbine,
HRSG and steam turbine unit would be aligned east / west along the southern part of
Area 1. The two air cooled condensers would be sited next to each other in the
south west corner of Area 1. However, this layout is preliminary at this stage, and will
be reviewed as the detailed design phases progress at later stages in the project.
7.2.47
New on site roads and paved areas will be provided as required. A branch from the
existing access road to the existing Damhead Creek CCGT Power Station will be
provided to allow for access to the Damhead Creek 2 site.
7.2.48
The two stacks will be 75 m high and will be similar in appearance to the existing
Damhead Creek CCGT Power Station stacks that are also 75 m in height. No bypass stacks will be required.
7.2.49
The illustrative layout is shown in Figure 5.1, although it should be noted that there
would potentially be changes to this layout design dependent on the selected
contractor. Any such changes would be agreed in writing with Medway Council.
7.2.50
The likely layout and maximum dimensions of Damhead Creek 2 are discussed in
Section 5 and are detailed in Table 5.1.
7.2.51
A steel palisade fence will be constructed around the Damhead Creek 2 site for
security reasons and the Damhead Creek 2 site will be fitted with closed circuit
television. Both of these items will link into the security fence and CCTV for the
7.2.52
A laydown area and space for offices for construction staff is shown by the blue
shaded region in Figure 2.1. Car parking facilities during construction will also be
provided as shown. No extra car parking facilities are required for Damhead Creek 2
during operation.
7.2.53
Alternatives to this layout would be to have a mirror image of the existing Damhead
Creek CCGT Power Station or perhaps a plant similar in layout to the existing
Damhead Creek CCGT Power Station but rotated through 90 degrees. However no
alternatives are at this stage considered to be optimised from an engineering
perspective with the potential phased development of Damhead Creek 2.
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EIA METHODOLOGY
SECTION 8
EIA METHODOLOGY
8
EIA METHODOLOGY
8.1
Overview
8.1.1
This ES has been prepared to document the findings of the EIA that has been
undertaken to determine the potential extent of any likely significant environmental
impacts (both positive and negative) with regard to the development of Damhead
Creek 2.
8.1.2
In accordance with the EIA Regulations, the ES goes on to identify measures
envisaged to avoid, reduce and, if possible, remedy any significant adverse impacts
identified. For impacts that cannot be entirely remedied, the ES identifies the residual
adverse effects once the mitigation is considered.
8.1.3
Monitoring has been recommended in some cases to help demonstrate that
Damhead Creek 2 is operating in compliance with the performance criteria identified
in this ES.
8.2
Environmental Impact Assessment Project Team
8.2.1
The EIA has been undertaken by Parsons Brinckerhoff Limited (PB), registered
Environmental Impact Assessors with the Institute of Environmental Management and
Assessment (IEMA) and a leading international organisation dedicated to the
promotion of sustainable development and of best practice standards in
environmental assessment and management.
8.2.2
In undertaking the various EIA studies, PB has been assisted by Pre-Construct
Archaeology (PCA) who have undertaken archaeological investigations, and Land
Management Services, an independent landscape architect group, who has
undertaken landscape and visual impact assessments of Damhead Creek 2. Dalton
Warner Davis (DWD) has provided planning policy advice. Penny Andersen
Associates undertook a number of ecological surveys.
8.3
Purpose of the Environmental Impact Assessment
8.3.1
The purpose and objective of an EIA is to determine whether or not the environmental
impact of a project, in this case the development of Damhead Creek 2, is within
acceptable limits. Additionally it serves to inform the design to ensure that wherever
possible environmental impacts are minimised in the design itself.
8.4
Methodology of the Environmental Impact Assessment
8.4.1
A number of steps are involved in an EIA.
provided here.
A brief description of these steps is
Identification of Environmental Baseline
8.4.2
In undertaking an EIA for any project it is important to identify the environmental
baseline at the site being considered. This allows the impacts of the proposed project
to be seen in the light of the existing environment and allows for better identification of
the most appropriate mitigation which could be employed to minimise these impacts.
8.4.3
A wide range of baseline date on the environment has been used for the purposes of
this EIA. Data and information has been gathered from a combination of sources.
This has included:
Documentary information;
Field survey information, including: ecological features; landscape character;
background noise levels; and traffic levels on the road network; and
Data from statutory and non-statutory consultees.
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EIA METHODOLOGY
8.4.4
The baseline conditions are then used to assess Damhead Creek 2 against the
potential construction / operation schedules.
Description of the Proposed Project and Identification of Potential Impacts
8.4.5
A full description of the proposed project should be included. This needs to provide
sufficient details so that any potential interactions, and thus impacts, with the
identified environmental baseline can be determined.
8.4.6
A full description of the Development is given in Section 5, with further details on the
Development site and its surroundings given in Section 6. Further details on specific
aspects of the Development, the Development site and its surroundings are included
in respective Sections of this ES as required.
8.4.7
The results of the EIA reported in this ES have adopted a number of potential
assessment scenarios, depending on eventual construction / operation schedules.
These are as follows:
Construction
8.4.8
At present, there are two likely construction programmes. These are:
A one phase programme, where the entire construction takes place between
2013 and 2016; or
A two phase programme, where Phase 1 construction (of first 500 MW unit)
takes place between 2016 and 2019, followed by Phase 2 construction (of
second 500 MW unit) between 2019 and 2022.
8.4.9
The assessment of construction effects in this ES considers both the above
construction scenarios.
Operational Year 2016 (assuming one phase construction scenario)
8.4.10
Damhead Creek 2 will commence generation of 1000 MW in 2016 assuming a one
phase construction scenario. The assessment for the 2016 operational year
considers the effects of Damhead Creek 2 against the baseline conditions expected
with regard to the relevant project schedule that would see construction works
commence as early as 2013.
Operational Years 2019 and 2022 (assuming two phase construction programme)
8.4.11
Phase 1 2019 – Damhead Creek 2 will commence generation of the first 500 MW in
2019 if Damhead Creek 2 is constructed in two phases. The assessment in this year
considers the effects of Damhead Creek 2 against the baseline conditions with regard
to the relevant project schedule which would see construction works commence in
2016.
8.4.12
Phase 2 2022 – Damhead Creek 2 will commence generation of all 1000 MW in 2022
if Damhead Creek 2 is constructed in two phases. The assessment in this year
considers the effects of Damhead Creek 2 against the baseline conditions with regard
to the relevant project schedule which would see construction works commence in
2019.
Evaluation and Quantification of Potential Impacts
8.4.13
To help evaluate and quantify the impact of Damhead Creek 2, environmental
significance criteria can be employed to ensure that the impacts are within acceptable
limits. Such criteria are developed to reflect the specific impact under consideration
and wherever possible are based on recognised methodologies such as those
identified by the Landscape Institute and the Institute for Environmental Management
Assessment.
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EIA METHODOLOGY
Monitoring and Mitigation Philosophy
8.4.14
Full consideration is then given to the potential mitigation techniques which could be
used to ensure that the adverse significant environmental impacts of the project are
minimised.
8.4.15
Damhead Creek 2 has and will continue to be developed in such a way that reduction
and, wherever possible, elimination of adverse significant environmental impacts
associated with the project are an integral component to the overall project design.
8.4.16
Where it is not possible to avoid adverse significant environmental effects, for
example where habitat will be permanently removed, plans have been prepared to
help compensate for the impact identified, such as additional habitat creation in a
suitable location.
8.5
Presentation of the Environmental Impact Assessment
8.5.1
Each of the EIA Sections contained within this ES have been broken down to include
a number of sub-sections. These are:
Introduction
This provides details of the key issues with regard to the specific environmental
impacts being considered.
This will provide a summary of the National, Regional and Local Planning
Policies which are relevant to the topic being assessed.
Assessment Methodology and Significant Criteria
This will provide details of the assessment methodology adopted for the
purposes of the EIA. The assessment methodology chosen reflects the relevant
guidelines and legislative standards. In addition, significance criteria to be used
to quantify the extent of the environmental impact of the proposed plant will be
identified.
This will identify the existing environment which could potentially be impacted on
by the proposed Development.
Potential Impacts
This will discuss the findings of the EIA studies, and will take in to consideration
the various possible construction / operation scenarios for the Development as
discussed above. Potential environmental impacts are identified as being: direct
and indirect; long, medium or short term; and, positive, neutral or negative. In
undertaking this assessment both quantitative and qualitative evaluations are
necessary, in varying degrees, depending on the nature of the environmental
impact being assessed. Significance of the environmental impacts identified is
addressed as appropriate with reference to the significance criteria established.
This will provide details of the mitigation measures that have been identified to
ensure that any potential adverse environmental impacts are either minimised or,
wherever possible, avoided altogether. In some cases, monitoring is identified to
allow it to be demonstrated that the mitigation measures employed are effective.
Residual Impacts
This will identify the adverse environmental impacts of the Development after the
recommended mitigation measures are implemented.
Cumulative Impacts
This will identify the likely significant environmental impacts of the Development
in conjunction with the various other projects, both existing and proposed in the
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EIA METHODOLOGY
vicinity. These have previously been discussed in Section 6. This assessment
will allow for the various possible construction ./ operation scenarios of Damhead
Creek 2.
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STAKEHOLDER CONSULTATIONS AND
ADDITIONAL STUDIES
SECTION 9
ADDITIONAL STUDIES
9
STAKEHOLDER CONSULTATIONS AND ADDITIONAL STUDIES
9.1
Overview
9.1.1
In undertaking the EIA and the associated supporting studies, ScottishPower and
their consultants have undertaken consultations with a variety of stakeholders. These
have included the Secretary of State, the local and regional authorities, local residents
and governmental and non-governmental organisations.
9.1.2
A summary of consultations undertaken to date and planned future consultations that
will be made are provided below. A summary of the supporting ‘stand-alone’
documentation is also provided.
9.2
Scoping of the Project
9.2.1
An initial scoping exercise was undertaken from December 2006 to April 2007 by
ERM. A Scoping Request / Scoping Study was produced which described the key
environmental issues that would require detailed evaluation as part of the EIA
process. A formal request for a Scoping Opinion was forwarded to the DTI (now
DECC), under Regulation 7 of the EIA Regulations. The Scoping Request was also
forwarded to other parties deemed to have a relevant interest in the Development.
9.2.2
The organisations consulted included:
DECC – Electricity Consents Team;
English Heritage;
Environment Agency;
The Highways Agency;
The Joint Nature Conservation Committee.
Kent County Council;
Medway Council;
Natural England; and
The Royal Society for the Protection of Birds (RSPB).
9.2.3
The Scoping Request was updated in March 2009 by PB, and was resubmitted to the
above parties to confirm that the proposed assessment methodology was still
appropriate given the intervening time between the original Scoping Request and the
submission of the Section 36 Application to DECC.
9.2.4
Consultation with interested parties has continued throughout the EIA for the
Development, through meetings and exchanges of correspondence.
9.2.5
ERM’s and PB’s Scoping Request and Scoping Opinion are included in Appendix C
and D respectively.
9.3
Residents Information Days
9.3.1
ScottishPower has also informed the public of proposals regarding Damhead Creek 2
through Residents Information Days where members of ScottishPower and their
consultancy teams were available to address the questions and queries of the local
community.
9.3.2
The Residents Information Days aimed to:
Raise awareness of Damhead Creek 2 and its likely impacts;
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ADDITIONAL STUDIES
Receive comments on Damhead Creek 2 and the scope of the EIA; and
Establish the concerns of stakeholders (be they real or perceived), in order that
these can be addressed and, where practical, mitigated.
9.3.3
ScottishPower held Residents Information Days in November 2006 at the Hoo
St Werburgh Village Hall.
9.3.4
A second set of Residents Information Days were held on Friday 20 March and
Saturday 21 March 2009 from 09:00 to 17:00 at BAe Sport and Social Club. Prior to
the Residents Information Days notices were published in the local papers and
individual invitations were sent to a number of householders in the vicinity of the site.
9.3.5
A Questionnaire / Feedback Form was available at the 2009 Resident’s Information
Days which visitors were encouraged to complete to give their opinion on the
Development and ask any questions in writing. A total of 20 Questionnaires were
completed. The Questionnaire can be seen in Appendix E, along with a table
showing the questions and the key concerns raised at the exhibition. The table also
directs the reader to the appropriate Section of the ES which addresses the question
or concern.
9.4
Additional Studies
9.4.1
A number of additional studies were undertaken in support of the Section 36
Application for Damhead Creek 2. These included a:
Combined Heat and Power (CHP) Assessment;
Carbon Capture Ready (CCR) Feasibility Study;
Design and Access Statement;
Flood Risk Assessment;
Statement to Inform; and
Transport Assessment.
9.4.2
9.4.3
Apart from the Flood Risk Assessment which is discussed in Section 15 and included
as Appendix H, these studies have been produced as ‘stand-alone’ documents, and
as such are not appended to this ES. However, summaries of these studies are
provided below.
Combined Heat and Power (CHP) Assessment
As part of their national energy policy, the UK Government is committed to promoting
the installation of CHP wherever economical. As such, they have set a target to
achieve at least 10 GWe of installed CHP capacity by 2010. To achieve this target
Government Policy has been formulated to support the provision of CHP generation
wherever feasible.
9.4.4
Therefore, to promote the use of CHP technology the Government expects
developers to submit information in support of notifications under Section 14 (1) of the
Energy Act 1976 and applications under Section 36 of the Electricity Act 1989, which
demonstrates that they have seriously explored opportunities for CHP.
9.4.5
The requirements of this assessment are outlined in the DTI (now DECC) guidance
document “Guidance on Background Information to Accompany Notifications under
Section 14 (1) of the Energy Act 1976 and Applications under Section 36 of the
Electricity Act 1989, December 2006”.
9.4.6
In line with Government policy and the guidance, ScottishPower has undertaken a
CHP Assessment to investigate the potential to incorporate a CHP element into the
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ADDITIONAL STUDIES
Development.
CHP will increase the energy utilisation associated with the
Development, and help to reduce the generation of greenhouse gases.
Guidance Requirements
9.4.7
The guidance requires developers to explore opportunities to use CHP, including
community heating, when developing proposals for new power stations and thus any
proposals submitted to the DECC are therefore expected to show that the developer
has actively explored the opportunities for CHP use.
9.4.8
Where heat opportunities have been identified, developers are required to show how
they have dealt with these in shaping their proposals.
9.4.9
The DECC suggests a number of potential heat markets as being worthy of
consideration in CHP assessments undertaken by developers, either singly or in
combination. In addition, the guidance suggests that developers contact Trade
Associations, Business Organisations and other interested parties to explore CHP
opportunities.
9.4.10
The organisations contacted as part of the CHP Assessment for the Development
included:
DECC – Electricity Developments Consents Team;
DEFRA – Climate and Energy: Households and Markets;
CHPQA (Quality Assurance for Combined Heat and Power);
Government Office for the Regional Planning Bodies: South East of England;
SEEDA (South East of England Development Agency);
Medway Council Development Control;
CHPA (Combined Heat and Power Association);
The Energy Saving Trust;
The Carbon Trust;
NHS Estates/Strategic Health Authority;
CPI (Confederation of Paper Industries); and,
HM Prisons Service: Property Services Group.
Identification of Potential CHP Opportunities
9.4.11
From the above consultations and appropriate investigations, Scottish Power has
identified potential users of heat from the proposed Development.
9.4.12
The most likely future potential user of heat would be the proposed Kingsnorth
Business Park, planned on land to the north of the proposed application site to be
developed by Goodman Developments Limited. Another potential future heat user
would be the proposed new Lodge Hill / Chattenden Settlement, approximately 6 km
to the west of the application site to be developed by Land Securities Group Plc.
Consultations and discussions have been held with both parties to establish their
expected heat demands and to explore future cooperation.
9.4.13
Further users may also be identified or indeed forthcoming in the event that the
proposed Development is consented and moves towards the detailed design stage.
9.4.14
In addition, ongoing consultation will continue between ScottishPower and local
industries / parties in an attempt to identify any possible future CHP opportunities.
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ADDITIONAL STUDIES
Carbon Capture Ready (CCR) Feasibility Study
9.4.15
Further information on the CCR Feasibility Study is provided in Section 19.
Design and Access Statement
9.4.16
A Design and Access Statement (DAS) was prepared in support of the Section 36
Application to demonstrate that ScottishPower had fully considered the design and
access issues surrounding Damhead Creek 2 in accordance with Section 3 of the
Government Circular ‘Guidance on Changes to the Development Control System’
(August 2006).
9.4.17
This Guidance advises that the DAS should cover both the design principles and
concepts which have been applied to Damhead Creek 2 and how issues relating to
access to Damhead Creek 2 have been dealt with.
9.4.18
The Guidance also acknowledges that the DAS must be "proportionate" to the
complexity of the application.
DAS
9.4.19
As such, a DAS for Damhead Creek 2 was prepared which covered the issues below.
Development Description
9.4.20
This included a description of how the Development fits into the physical, social,
economic and planning policy context of the local area. In addition, discussion was
provided on the appropriateness of the Development's use.
Development Amount
9.4.21
This included discussion on how much Development would be built on the application
site.
Development Design
9.4.22
This included discussion on the amount, use, layout, scale, landscaping and
appearance of the Development.
9.4.23
Access Arrangements
9.4.24
This presented information on the access arrangements to the Development,
including those required during construction and operation, in addition to inclusive
(human) access.
Statement to Inform
9.4.25
Under Article 6(3) of the Council Directive 92/43/EEC on the Conservation of Natural
Habitats and of Wild Fauna and Flora 1992 (Habitats Directive) an Appropriate
Assessment (AA) is required to be undertaken by the competent authority where a
plan or project, not directly connected with or necessary to the management of a
Natura 2000 site (European Site), is likely to have a significant effect on a European
Site. The Habitats Directive was transposed into UK Legislation via the Conservation
(Natural Habitats &c) Regulations 1994 (Habitats Regulations).
9.4.26
The Habitats Regulations provide protection for certain species and habitats through
the designation of European Sites, which are candidate Special Areas of
Conservation (cSAC), Special Areas of Conservation (SAC) and Special Protection
Areas (SPA) respectively. Collectively these European Sites are known as “Natura
2000” Sites or the “Natura 2000” Network. In addition, Government Circular 06/2005
‘Biodiversity and Geological Conservation – Statutory Obligations and their Impact
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ADDITIONAL STUDIES
within the Planning System’ (August 2005) states that protection should also be
afforded to potential SPAs (pSPA) and Ramsar Sites.
9.4.27
As such, an AA is triggered when the Secretary of State for the DECC determines
that a plan or project not directly connected with or necessary to the management of a
European Site is likely to have a significant effect on that Site either individually or in
combination with other plans or projects. Therefore, where an AA is required, it must
assess whether the plan or project will have an adverse affect on the integrity of a
European Site.
Statement to Inform Conclusions
9.4.28
Whilst the ultimate need for an AA to be undertaken has not been decided, a
Statement to Inform was prepared for Damhead Creek 2 and considered the potential
effects associated with the construction and operation of the Development to
European Sites located within 10 km.
9.4.29
Based on information available for Damhead Creek 2, and supported by published
data from other sources (mainly the Kingsnorth Units 5 and 6 and the Kingsnorth
Business Park), the evidence was sufficiently compelling to overcome any
uncertainties surrounding predictions at this site.
9.4.30
It was therefore concluded that the development of Damhead Creek 2 would not
cause a significant adverse effect on the integrity of the relevant European Sites
either alone or in combination with the development of Kingsnorth Units 5 and 6 and
the Kingsnorth Business Park.
Transport Assessment
9.4.31
A transport assessment was prepared to fully assess the effects of Damhead Creek 2
on the local road network, in addition to other transport infrastructure. In the transport
assessment, both the existing and proposed trip generations and routings were
examined to determine the resultant impacts on local infrastructure. Site accessibility
was also considered, and an analysis was made of the potential for staff to use noncar modes of travel.
9.4.32
This transport assessment was prepared in accordance with:
Guidance on Transport Assessment, Department for Transport (DfT);
Planning Policy Guidance 13 (PPG13);
Local Transport Plan 2006-2011, Medway Council;
Advice Note TA79/99 from the Design Manual for Roads and Bridges; and
National Road Traffic Forecasts (Great Britain) 1997, DfT.
Transport Assessment Conclusions
9.4.33
The transport assessment demonstrated that successful implementation of an agreed
Transport Management Plan, in addition to mitigation and monitoring schemes, would
ensure that all traffic associated with the construction and operation of Damhead
Creek 2 would have an insignificant impact on the local transport infrastructure. This
would be both in terms of isolated operation and operation in conjunction with the
development of Kingsnorth Units 5 and 6 and the Kingsnorth Business Park.
9.5
Future Consultations
9.5.1
On completion of the ES and submission of the Section 36 Application, ScottishPower
must publicise the application by placing a notice within a newspaper available in the
locality of the Development, a national newspaper and within the London Gazette.
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9.5.2
Public notices will also be placed at a number of locations within the vicinity of the
Development site. Copies of the ES will be made available at key locations within the
area so that members of the public may view the ES and make any representations
on the application.
9.5.3
The local council (Medway Council) will also place a copy of the ES on their Planning
Register together with any related documents. Within four months of the application
being received, Medway Council will communicate their views on the application to
DECC, who will subsequently make a decision on whether or not to give consent to
Damhead Creek 2.
9.5.4
Throughout the determination process ScottishPower will continue to address any
questions or concerns raised by stakeholders with regard to Damhead Creek 2.
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SECTION 10
AIR QUALITY
SECTION 10
AIR QUALITY
10
AIR QUALITY
10.1
Summary
10.1.1
Dust may be generated during several activities associated with the construction
works, for example excavation work. It is very unlikely during most weather
conditions that dust generated at the Damhead Creek 2 site will cause a nuisance at
sensitive receptors in the area due to distance and the proposed mitigation measures
that will be employed on the Damhead Creek 2 site.
10.1.2
During the operation of Damhead Creek 2, the principal atmospheric emissions of
concern will be NOx. Emission levels of NOx will be maintained below 50 mg/Nm3
(25 ppm) as required by the LCPD using DLN technology. During normal operations
there will be no visible plume from the two 75 m stacks that will serve to disperse flue
gases for Damhead Creek 2.
10.1.3
There are a number of automatic monitoring sites for air quality that are, or have
been, operated on behalf of the Department for Environment, Food & Rural Affairs
(DEFRA) in the UK. The results from the monitoring sites are available on the
Internet. The nearest monitoring stations to the Damhead Creek 2 site are Rochester
and Gillingham Strand and show that air quality in the area of Damhead Creek 2 is
generally good and well within the guidelines set out in the UK Air Quality Strategy
(AQS) objectives.
10.1.4
As part of the EIA, a dispersion modelling exercise has been undertaken. Emissions
of NO2 from Damhead Creek 2 have been modelled and the ground level
concentrations calculated and compared to the relevant standards whilst also
considering existing background levels. The emissions from the existing Damhead
Creek CCGT Power Station that will operate alongside Damhead Creek 2 have also
been modelled to quantify the overall impact of the Damhead Creek Power
Generation Development on local air quality. Damhead Creek 2 has also been
assessed cumulatively with the emissions from the proposed Kingsnorth Units 5 and
6. Other plant in the general area such as the existing oil plant at Grain, the CCGT
under construction at Grain and the existing CCGT at Medway are considered to be
too far away to give rise to significant cumulative impacts.
10.1.5
A conservative view of the operation of Damhead Creek 2 under specific scenarios
has been adopted in the modelling so that a likely “worst case” scenario is presented.
The purpose of using this conservative approach is to ensure that the maximum
predicted impact within the potential operating regime of Damhead Creek 2 is
considered. This ensures that there is a “factor of safety” built into the air quality
assessment. The results of the modelling have been compared to AQS objectives.
10.1.6
Key findings from the analysis are:
Damhead Creek 2 will not give rise to high annual ground level concentrations of
NO2. The predicted maximum long-term NO2 concentration due to Damhead
3
Creek 2 is predicted to be 0.4 g/m , well within the long term AQS objective of
3
40 µg/m . The maximum concentration occurs at a point just over 2.2 km to the
north east of the Damhead Creek 2 site in the vicinity of Stoke Saltings just off
the coast of Stoke.
The predicted maximum increase in short term NO2 concentrations due to the
3
operation of Damhead Creek 2 in isolation is just 10.3 g/m , which is just over
5 per cent of the AQS objective. The maximum concentration as with the
maximum long-term prediction occurs at a point just over 2.2 km to the north
east of the Damhead Creek 2 site in the vicinity of Stoke Saltings just off the
coast of Stoke.
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AIR QUALITY
Damhead Creek 2 will not significantly increase ground level concentrations of
NO2 at the various AQMA in the area. In addition when considered along with
the existing ground level concentrations in the surrounding area it is not
considered that Damhead Creek 2 will give rise to any additional exceedances of
any of the relevant AQS objectives.
10.1.7
It was concluded from the assessment undertaken that the impact of the atmospheric
emissions from Damhead Creek 2 will be well within the AQS objectives even when
considered in conjunction with the existing background levels.
10.1.8
The cumulative impact assessment has shown that Damhead Creek 2, even when
operating in conjunction with the existing Damhead Creek CCGT Power Station and
the proposed Kingsnorth Units 5 and 6 will not give rise to exceedances of the UK
AQS.
10.1.9
Damhead Creek 2 will have a positive net effect on climate change as it will likely
replace other fossil fuel sources of electricity generation that have greater carbon
dioxide emissions per unit output. Damhead Creek 2 will be equipped so as to be
carbon capture ready with space made available in the Damhead Creek 2 design to
allow for the fitting of a carbon capture plant should a viable means of carbon dioxide
capture and transport become available to the site in the future. This is discussed
further in the CCR Feasibility Study.
10.2
Introduction
10.2.1
This Section presents the air quality impact assessment, and includes the
assessment methodology and significance criteria adopted in undertaking the
assessment; the baseline conditions on which Damhead Creek 2's impact is
assessed; the likely potential (pre-mitigation) significant environmental impacts which
Damhead Creek 2 may have; the mitigation measures to be adopted; and the
resultant residual (post-mitigation) significant environmental impacts of the
construction and operation of Damhead Creek 2. Cumulative residual impacts are
also considered within this Section.
10.3
10.3.1
Section 4 provides the planning policy context. The policies listed below have
informed the assessment process, to which reference has been made in Section 4. A
full transcript of these policies is contained in Volume 2 Appendix B.
South East Plan (SEP)
NRM9
Air Quality
Kent and Medway Structure Plan (KMSP)
NR5
Pollution Impacts
NR7
Air Quality Management Areas
Medway Local Plan (MLP)
BNE24
Air Quality
10.4
Ambient Air Quality Benchmarks
10.4.1
The assessment of the impact on air quality is based on the predicted contributions to
ground level concentrations of pollutants. This is a requirement of the Environment
Act 1995 and the UK National Air Quality Strategy (NAQS), which have set standards
and objectives for these ambient concentrations.
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10.4.2
The UK Air Quality Strategy (2007) (AQS) has specified a series of standards and
objectives for air quality in the UK. Given that Damhead Creek 2 will be fired
exclusively on natural gas the only pollutant relevant to Damhead Creek 2 is nitrogen
dioxide with other pollutants being present in such small amounts as to be irrelevant.
The AQS objectives for NO2 are summarised in Table 10.1.
TABLE 10.1: UK AIR QUALITY STRATEGY OBJECTIVES FOR THE
PROTECTION OF HUMAN HEALTH
Parameter
Reference period
Nitrogen dioxide
Compliance
date
Statutory ground
level concentration
limit values ( g/m3)
Number of
permitted
exceedences
Hourly
2005
200
18
Annual
2005
40
-
10.4.3
The European Union has also set ambient air quality objectives for nitrogen dioxide
(NO2) (Directive 99/30/EC adopted 22 April 1999). The guidelines include the same
limit values and numbers of permitted exceedances as the UK AQS, however the
deadlines for meeting the EU guidelines are later than those for the UK, requiring
compliance by 31st December 2010.
10.4.4
In addition to the objectives identified above, the European Union has set ambient air
quality guidelines for oxides of nitrogen (NOx) for the protection of ecosystems. This
imposes an annual limit for NOX of 30 g/m 3.
10.4.5
It is important to define the areas in which the limit for the protection of ecosystems is
to be achieved. Directive 99/30/EC states that sampling points should be:
At least 5 km from major emission sources; or
20 km from an agglomeration, which is defined as an area with a population of
more than 250,000; and
Representative of areas of at least 1000 km 2.
10.4.6
The Government and devolved administrations intend that these objectives apply in
those parts of the UK that are:
More than 20 km from an agglomeration;
More than 5 km away from industrial sources regulated under Part A of the 1990
Environmental Protection Act;
More than 5 km from motorways; and
Built up areas of more than 5000 people.
10.4.7
Given that the existing Damhead Creek and Kingsnorth Power Stations are both Part
A installations the above limit is not applicable within 5 km of the Damhead Creek 2
site. Indeed, due to the nature of land use in the surrounding area the limit does not
apply anywhere within the likely sphere of influence of Damhead Creek 2.
Nevertheless, the impact of Damhead Creek 2 has been benchmarked against these
requirements with further discussion on Damhead Creek 2's impacts to ecologically
sensitive sites included in Section 13.
Significance Criteria
10.4.8
The EA suggest in their Technical Guidance note H1, Environmental Assessment and
Appraisal of Best Available Techniques (BAT), that results of modelling can be
considered to be “significant” where they predict that the contribution from the plant
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will exceed 10 per cent of the short term objectives (up to 24 hour averages) and
1 per cent of the long term objectives/EAL (monthly/annual results etc).
10.4.9
The EA significance thresholds will be applied for the purposes of the impact
assessment though it is noted that the EA guidance does not distinguish between
processes or the extent of the area of impact. Whilst these criteria will be referenced
it is therefore important that results are seen in a qualitative rather than a mere
quantitative light.
10.5
10.5.1
Receptors relevant to the assessment exist essentially anywhere outside the confines
of the existing Damhead Creek CCGT Power Station and the Damhead Creek 2 site.
Receptors that are especially relevant, however, are local residences where people
spend a large percentage of their time. The nearest residences to Damhead Creek 2
are located at Eshcol Road, about 1 km to the west of the Damhead Creek 2 site and
Benuncle Farm and White Hill Farm some 1.1 km to the north-west and north
respectively.
10.5.2
Other receptors that must be given special consideration in any air quality
assessment include air quality management areas (AQMAs) as designated by the
local council and areas of poor air quality. It is important that Damhead Creek 2 does
not lead to either the exacerbation of existing problems encountered at AQMAs or the
establishment of additional AQMAs through its operation.
Ambient Air Quality
10.5.3
Baseline conditions can also be determined by examining local authority ambient air
quality data. Local authorities have duties under Part IV of the Environment Act 1995
to assess air quality within their administrative areas. Full details of the duties are set
out in the UK AQS. If pollutant levels are likely to exceed statutory objectives, then
they must declare an AQMA and draft an action plan to achieve the objectives. The
Department of Environment Transport and the Regions (DETR) (as was) have issued
technical guidance to the local authorities to assist in undertaking this task. The
process comprises three stages:
Stage 1 is intended to assist the authority in determining which existing and
proposed sources may have a significant impact on air quality.
Stage 2 is intended to provide additional screening of pollutant concentrations in
the area and determine the risk of non-compliance with the air quality objective
by the relevant future year.
Stage 3 entails a detailed and accurate appraisal of the potential impacts of the
outcome of Stages 1 and 2; the authority is required to determine both the
magnitude and the geographical extent of any likely exceedances of the
objectives.
10.5.4
At the end of the three stage process the local authority should have identified areas
where there are likely exceedances of the objectives and for each pollutant calculate:
How great an improvement is needed to meet the objectives; and
The extent to which different sources contribute to the problem.
10.5.5
This gives the authorities a clear picture of the sources which can be controlled or
influenced and aid the authority to target more effectively and ensure that the relative
contributions of industry, transport and other sectors to the solution are cost effective
and proportionate when producing their action plan.
10.5.6
As part of the ongoing review and assessment process of AQMAs, a phased
approach has been adopted to ensure that the level of assessment is commensurate
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with the risk of an air quality objective being exceeded. Therefore, each local
authority is required to undertake an Updating and Screening Assessment (USA) of
the AQMAs in their administrative area in order to identify changes which have
occurred since the previous review and assessment and which could potentially lead
to a risk of an air quality objective being exceeded. Where a risk has been identified
the local authority is required to undertake a more detailed assessment to determine
the likelihood of an exceedance and revise the AQMA as appropriate. The last USA
for the Medway area was undertaken in 2006.
10.5.7
Medway Council identified a number of AQMA’s including the following:
Chatham Centre,
Cuxton Road,
Frindsbury Road,
Maidstone Road,
Rochester Centre, and
Strood Centre.
10.5.8
All the above AQMAs are designated for NO2 and are located along the routes of
busy roads in the Medway area. In all cases the areas designated are fairly small and
will primarily be the result of pollution from road traffic.
10.5.9
There are a number of automatic monitoring sites that are or have been operated on
behalf of DEFRA in the UK. The results from the monitoring sites are available on the
Internet. The nearest monitoring station to the Damhead Creek 2 site is that at
Rochester (grid reference 583100, 176200). A second monitoring station is located at
Gillingham Strand (grid reference 578400, 169300) and is operated by E.ON UK.
10.5.10
These monitoring stations have been in operation for a number of years and have
been recording data, which will include contributions from both the existing Damhead
Creek and Kingsnorth Power Stations. Results for the years 2001 to 2005 are shown
in Table 10.2 with the locations shown in Figure 10.1.
TABLE 10.2: AMBIENT AIR QUALITY RECORDS NO2 ( g/m3)
Rochester
th
Gillingham Strand
th
Year
19 Highest
Annual
19 Highest
Annual
2001
78
22.1
92
27.1
2002
71
21.2
85
24.7
2003
80
21.8
99
27.6
2004
76
20.4
90
24.9
2005
74
18.8
87
23.3
AQS
200
40
200
40
10.5.11
In addition to the above permanent monitoring stations, Medway Council has
undertaken diffusion tube sampling for NO 2 at a number of locations identified in
Table 10.3 whilst the ‘UK NO2 diffusion tube survey’ has also collected data in the
area, which is presented in Table 10.4.
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TABLE 10.3: NO2 DIFFUSION TUBE RESULTS FROM MEDWAY COUNCIL
(ANNUAL) ( g/m3)
Year
High Street
,Rainham
Gillingham
Gate,
Gillingham
(roadside)
Stoke
Primary
School
Rochester
(rural)
Long Catlis
Road
Gillingham
Luton Road
Chatham
Pier Road
Strand
Gillingham
(background)
(background)
(roadside)
Lower
Stoke A228
Rochester
(roadside)
(roadside)
2002
51
27
27
-
-
-
-
2003
54
28
31
41
26
-
-
2004
33
20
28
31
31
30
27
2005
39
25
20
44
25
40
35
AQS
40
40
40
40
40
40
40
TABLE 10.4: NO2 DIFFUSION TUBE RESULTS FROM UK DIFFUSION TUBE
SURVEY (ANNUAL) ( g/m3)
Year
Gillingham 1N
(roadside)
Gillingham 4N
(background)
Rochester 1N
(roadside)
Rochester 3N
(background)
2002
51
27
27
-
2003
54
28
31
41
2004
33
20
28
31
2005
39
25
20
44
AQS
40
40
40
40
10.5.12
The diffusion tube locations are noted in the tables, which show significantly higher
annual NO2 concentrations for locations adjacent to roads than for other urban and
rural areas. This is to be expected as traffic will generate NO2 through the
combustion of liquid fuels. The results are not representative of the experience of
members of the general public. Concentrations observed for urban and rural
locations are generally lower than those observed at roadside locations and are more
consistent with the long-term monitoring station results presented previously in Table
10.2 which should be more reliable due to the more accurate measurement
techniques employed.
10.5.13
Table 10.5 gives detail of the maximum annual ground level concentrations estimated
for Medway Council by NETCEN including NO2 projections for the years 2005 and
2010. The table shows a predicted improvement in ground level concentrations of
NO2 over the coming years.
TABLE 10.5: ANNUAL POLLUTANT LEVELS ESTIMATED FOR LOCAL
COUNCILS ( g/m3)
Pollutant
NO2
10.5.14
Year
Medway Council
2004
27.6
2005
25.4
2010
23.0
The above demonstrates that NO2 levels in the area have not come close to
exceeding the objectives adopted in the 2007 AQS in recent years for short term
concentrations. Long term concentrations do exceed the AQS objectives when
compared to the AQS of 30 g/m3 though it should be noted that exceedances are
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limited to areas close to roads which suffer from NO2 generated by road traffic and
are not representative of the ambient air quality experienced by the majority of the
general public.
10.6
Potential Impacts
10.6.1
This subsection reviews the potential air pollution generated by the construction and
operation of Damhead Creek 2.
Construction
10.6.2
Dust could be emitted during several activities associated with the construction works
should preventative measures not be taken. Dust could arise from: earth moving
operations for site levelling (that will be minimal), back filling and foundations; removal
of spoil, site stripping, blow-off and spillage from vehicles; concreting operations, site
reinstatement and road construction and during wind blow over bare dry construction
areas.
10.6.3
Only with high wind speeds would long distance transport of dust and the potential for
soiling of buildings occur. In these conditions more dust would also be created at
source. The extent of any such emissions of dust is very dependent on wind speed,
ground conditions, the prevalence of hot, dry conditions and the use of preventative
measures.
10.6.4
The dust particles that may be emitted during construction would be of large diameter
and would therefore tend to resettle on the ground within 100 to 500 m of the
Damhead Creek 2 site. Approximately 70 per cent of the dust would generally settle
out of the atmosphere within 200 m of the source, and less than 10 per cent could be
expected to remain at a distance of 400 m. With the nearest housing being at a
distance of nearly 1 km away impacts associated with dust creation should be
minimal. This will be helped by the roads and hedgerows lying between the
Damhead Creek 2 site and the nearest residences meaning that soiling of residential
buildings is unlikely to occur.
10.6.5
Dust emissions from the Damhead Creek 2 site will not be more onerous than those
normally encountered on construction sites and will be similar to those experienced
by residents during the construction of the existing Damhead Creek CCGT Power
Station. Construction operations will be conducted so as to minimise the generation
and spread of dust. ScottishPower will require its contractors to implement a
comprehensive mitigation and monitoring programme. This will prevent construction
work generating levels of atmospheric dust that would constitute a health hazard or
nuisance to people working on the Damhead Creek 2 site, at the existing Damhead
Creek CCGT Power Station or living nearby.
10.6.6
As the mitigation measures outlined below will be employed, dust is unlikely to result
in any significant environmental impact during the construction phase.
10.6.7
The use of wheel and chassis washing units will also help to prevent the transport of
mud and dust onto off-site routes.
10.6.8
The commissioning of each unit of Damhead Creek 2 will take about 12 weeks. The
purpose of commissioning is to adjust the performance of the newly installed plant to
achieve all required operational and environmental performance criteria. Firing of the
gas turbines will be intermittent during this period. It is possible that during
commissioning the emissions of oxides of nitrogen will be temporarily higher than
those during normal operation, however still well within the relevant air quality limits.
However, operational periods during commissioning are often short and operation is
frequently at low load. Thus the total mass emissions of oxides of nitrogen during
commissioning will be low.
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10.6.9
There will be no noticeable difference in terms of additional or lesser disturbance
should construction occur over two phases as may be the case due to the NGC Grid
connection dates though of course the development would take place over a longer
time scale.
Operation
10.6.10
The Environment Agency in their Technical Guidance Note H1, Environmental
Assessment and Appraisal of Best Available Techniques (BAT), provides guidance to
allow for the determination of whether detailed assessment, via dispersion modelling,
of various pollutants that will be emitted, as part of the combustion process, is
required.
10.6.11
The H1 assessment imposes a high level calculation to determine the likely long and
short term ground level concentrations that might arise from an installation based on
release rate of the pollutant to be assessed and a dispersion factor derived from the
installation's stack height.
10.6.12
To determine the pollutants that should be considered as part of the more detailed
dispersion modelling exercise, calculations have been undertaken using the
methodology proscribed in Section 3.3.1 of the Technical Guidance Note H1 based
on the stack height, emissions rates and parameters shown in Table 10.8. The
results of these calculations showed the only emissions of concern from Damhead
Creek 2 are those of NO2 with other pollutants not being present in sufficient
quantities in the flue gases to pose a likely significant impact to local air quality.
10.6.13
The contribution to ground level concentrations of NO2 pollutants due to Damhead
Creek 2 have been quantitatively assessed using dispersion modelling techniques
and have been compared with the background air quality in the area and with EU
legislation and UK guidelines.
10.6.14
Natural gas will be used as the fuel in the gas turbines. It is an inherently clean fuel
which results in much lower NOx and close to zero SO2 emissions when compared
with fuels such as oil or coal. Natural gas has a higher hydrogen content and calorific
value than oil or coal, which results in comparatively much lower carbon dioxide
emissions per unit of electricity generated.
10.6.15
Combustion in gas turbines is conducted at high excess air rates, typically 200300 per cent excess air. There are, therefore, very low levels of carbon monoxide,
unburnt carbon (i.e., particulate matter) or unburnt hydrocarbons present in the
products of combustion.
10.6.16
The combustion of natural gas, therefore, results in the emission of flue gases
containing carbon dioxide, water vapour, oxygen, nitrogen, carbon monoxide (CO),
NOx and negligible traces of SO2.
10.6.17
The emissions of NOx from all gas turbines will be below 50 mg/Nm 3 at reference
conditions when the gas turbine is operating at greater than 70 per cent of the rated
output in accordance with the requirements of the Large Combustion Plant Directive
‘new’ new plant standard for gas turbines.
ScottishPower will require the
manufacturer to guarantee these NOx emissions levels.
10.6.18
The emissions of NOx during gas firing will be balanced to keep those of CO below
the Environment Agency guideline of 50 mg/Nm 3.
10.6.19
During normal operation and under normal meteorological conditions all gaseous
discharges from the chimney will be colourless and odourless. At start-up, under
certain weather conditions, it may be possible for a faint brown haze to be seen for a
few minutes only.
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10.6.20
All environmental controls at the plant and all emissions will comply with the
conditions and limits set by the Environment Agency in the EPR Permit to operate
Damhead Creek 2.
Control of Oxides of Nitrogen during Combustion
10.6.21
The formation of oxides of nitrogen in the combustion of fossil fuels is unavoidable.
NO is the principal oxide of nitrogen produced, with a small proportion of NO2. The
ratio of NO2 to NO is approximately 1:19.
10.6.22
When NOx was first identified as a harmful pollutant, the exhausts of gas turbines
typically contained from 280 to 470 mg/Nm3 NOx. The problem having been identified
the manufacturers of gas turbines were able to reduce the levels to about
235 mg/Nm3 by fairly simple changes to air and fuel distribution in the combustors.
10.6.23
Since the NOx formation from atmospheric nitrogen is strongly dependent on the
maximum flame temperature and also the time the hot gases remain at this
temperature, the thermal NOx component can be reduced either by cooling the flames
by the injection of steam or water into the combustion zone or by the use of DLN
Burners.
10.6.24
It is proposed for Damhead Creek 2, that the emissions of NOx from the gas turbines
during natural gas firing be controlled by the use of DLN Burners. The concentrations
of oxides of nitrogen in the exhaust gases at the exit from the gas turbines will
therefore not exceed 50 mg/Nm3 (24.4 ppm).
10.6.25
DLN Burner technology comprises either pre-mix or hybrid burners, which burn fuel
with excess air and maintain the fuel air ratio across the load range. The main
volume of combustion air is supplied to dilute the flame and inhibit further NO x
formation. As flame stability cannot be maintained during periods of low load or startup the formation of oxides of nitrogen cannot be reduced at these times.
Nevertheless this will not challenge the relevant air quality limits.
10.6.26
When gas firing, for short periods during start-up (about 180 minutes) and shut-down
(about 60 minutes), the DLN burners will not be effective. During these periods, NOx
concentrations will be increased, however the volumetric flow of the flue gasses is
greatly reduced. Therefore, the mass emissions, and resulting impact, will not be
significant.
Conversion of Nitric Oxide to Nitrogen Dioxide
10.6.27
NOx emissions from Damhead Creek 2 will consist of the gases NO and NO2. It is
only NO2 that is of concern in terms of direct health and environmental effects.
However, NO is a source of NO2 in the atmosphere. The gases are in equilibrium in
the air, with NO predominating at the stack exit. As the plume cools, the equilibrium
changes, resulting in a predominance of NO2.
10.6.28
NO is oxidized to NO2 mainly by reaction with ozone. Within 5 km of the source less
than 20 per cent of the NO will have converted to NO2 under stable conditions. Under
unstable conditions with more atmospheric mixing, up to 50 per cent of the nitric oxide
may have converted to NO2. The rate of conversion of nitric oxide to NO2 increases
with rising ozone concentration, wind speed and solar radiation.
10.6.29
For assessing the impacts on air quality of emissions to atmosphere from large
combustion sources, such as gas-fuelled power stations, it is important that realistic
estimates are made of how much nitric oxide would be oxidized to nitrogen dioxide at
all receptors considered.
10.6.30
The rate of oxidation of nitric oxide to nitrogen dioxide depends on both the chemical
reaction rates and the dispersion of the plume in the atmosphere. The oxidation rate
is dependent on a number of factors that include the prevailing concentration of
ozone, the wind speed and the atmospheric stability.
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10.6.31
Between 1975 and 1985 about 60 sets of measurements were made of the
concentrations of nitric oxide and nitrogen dioxide in various power station plumes.
These measurements were carried out under widely varying weather conditions at
altitudes between 200 m and 700 m. From the data collected, an empirical
relationship for the percentage oxidation in a power station plume based on downwind
distance, season of the year, wind speed and ambient ozone concentration may be
described by the following equation (which is sometime referred to as Janssen’s
equation):
NO2
NO x
A 1 exp
x
where x is the distance downwind (km) of the emission point and
and A are
constants dependent on time of year and derived from the measurements of wind
speed and ozone concentrations.
10.6.32
For a typical gas fired power station the peak ground level concentration of the oxides
of nitrogen will occur within a few kilometres. The empirical relationship has been
used to estimate the percentage oxidation for each hour during 2001 for downwind
distances from Damhead Creek 2. These estimates were made using hourly average
meteorological data from Manston; which is the closest monitoring station with
sufficiently complete data, and hourly average ozone concentrations from Rochester,
the nearest monitoring site which measures ozone. Table 10.6 shows the minimum,
maximum and annual average estimates of NO2 in the plume for selected distances
downwind of the plume, the figure takes into account the ratio of NO to NO2 in the
plume on exit from the stack.
TABLE 10.6: ESTIMATES OF THE PERCENTAGE OF NITROGEN DIOXIDE (NO2)
IN OXIDES OF NITROGEN (NOX) 2001
Downwind
distance (km)
Percentage nitrogen dioxide (NO2)
Lowest one hour
average
Highest one hour average
Annual average
1
2.4
16.0
6.8
2
4.7
29.0
13.0
3
6.8
39.7
18.5
5
10.8
55.6
27.9
10
19.3
76.1
44.7
10.6.33
Based on the principles outlined above, the average proportion of nitrogen dioxide
within 2 km of the stack will be 13.0 per cent. The highest percentage oxidation for
any hour during 2001 for impacts that occur within 2 km of the stack is 29.0 per cent.
The predictions therefore suggest that out to distances of 3 km from the Damhead
Creek 2 site, the percentage oxidation of nitric oxide to nitrogen dioxide in the plume
will on average be just over 18.5 per cent.
10.6.34
The maximum conversion factor calculated for each receptor can been applied to the
predicted levels of NOx due to Damhead Creek 2 to give a conservative estimate of
NO2 contributions at each individual receptor based on the data in Table 10.6 and the
distance of the receptor from the stack modelled. As part of the calculation of the
conversion, the centre point between the two stacks at Damhead Creek 2 will be used
as the reference point for the conversion.
Atmospheric Dispersion Modelling
10.6.35
Atmospheric dispersion modelling can predict the ground level concentrations that
occur due to the emissions from an elevated stack point source. This subsection
describes the key aspects of the dispersion modelling process.
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10.6.36
When flue gases are discharged from a chimney they have two sources of
momentum. One is related to the velocity of discharge. This is usually designed to
be in excess of 15 metres per second as this value has been found to be sufficient to
avoid immediate downwash of the plume.
10.6.37
The momentum from the velocity of discharge is soon dissipated.
10.6.38
The second source of momentum is much more significant and is related to the
discharge temperature of the flue gases. The flue gases being warmer than the
surrounding atmosphere into which they are discharged, have a buoyancy and thus
rise. This process continues until the flue gases have cooled to the same
temperature as the surrounding air.
10.6.39
Mathematical models calculate the effects of these two sources of momentum and
determine the height to which the flue gases will rise. This height plus the height of
the chimney gives an effective chimney height.
10.6.40
The mathematical model then determines the dispersion of the flue gases from this
effective chimney height. Note that the effective chimney height can be many times
greater than the actual chimney height due to the large amount of heat present in the
flue gases.
10.6.41
Dispersion occurs as a result of turbulence, and turbulence can result from both
buoyancy effects and wind shear (also called mechanical) effects.
10.6.42
As an example of buoyancy effects, on a sunny day, solar heating creates turbulence
by heating the ground and the air near the ground. The buoyancy of the heated
bubbles of air causes it to rise, creating turbulence. These are the thermals
experienced by small plane and glider pilots on sunny days. These can also rapidly
disperse a plume in the surrounding air. At night, during stable conditions, the
buoyancy effect is to suppress rather than cause or enhance turbulence.
10.6.43
Wind shear as a cause of turbulence is well known to pilots as well. Wind shear
effects, important to air pollution modelling, result from high (several meters per
second) wind speeds near the ground. Since the wind speed at the ground is zero,
any high wind speeds result in substantial wind shear. Wind shear dominates over
buoyancy effects not only under high wind conditions, but also near the ground under
any conditions.
10.6.44
As a result of this, two parameters are used to define the “stability” of the atmosphere.
The first is the friction velocity. This is a measure of wind shear. Shear stress per
unit mass has the units of velocity squared. The square root of this is the friction
velocity.
10.6.45
The second parameter is a stability term called the Monin-Obukhov length. As
mentioned above, shear stress always dominates near the ground. The height above
the ground, where buoyancy effects begin to dominate (generating turbulence in
convective conditions or suppressing turbulence in stable conditions) is called the
Monin-Obukhov length. This can be thought of as a depth of the neutral (i.e. sheardominated) flow. The Monin-Obukhov length is positive for stable conditions, and
negative for convective. Near-neutral conditions are characterised by very large
negative, or very large, positive Monin-Obukhov lengths. Very stable conditions have
Monin-Obukhov length of a few metres to a few tens of metres, while very unstable
conditions have negative lengths of about the same size.
The Dispersion Model and Inputs
10.6.46
To gauge the impact of Damhead Creek 2, a dispersion modelling exercise has been
undertaken. The dispersion models available and accepted by the UK Environment
Agency for point sources are AERMOD and ADMS. Both are second generation
models developed in the US and the UK respectively.
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10.6.47
AERMOD was selected for the dispersion modelling of the proposed plant for
consistency with previous modelling exercises undertaken for the existing Damhead
Creek CCGT Power Station.
10.6.48
Building downwash structures are those which subject the plume from the stack to
wake effects. The effect is generally to pull the plume down to the ground closer to
the stack and not allow the plume to disperse as effectively thus increasing ground
level concentrations. Potential downwash structures are those which are located
within 5L of the stack, L, being the lesser of the height of the building, and the
maximum projected width of the building.
10.6.49
Additionally if a stack is higher than the height of the building plus 1.5L, then the
building is not a downwash structure. A list of the buildings included in the modelling
undertaken are included in Table 10.7. These include buildings associated with the
new Kingsnorth Units 5 and 6 which are likely to be built at some point in the near
future. It was considered that it was important to include these buildings in the stack
height determination as the downwash effect of these buildings would impact on
Damhead Creek 2. The existing boiler at Kingsnorth was also included in the
modelling though due to distance the impact of the building would be negligible.
TABLE 10.7: DISPERSION MODELLING BUILDING DATA (AERMOD)
Height (m)
Angle
Dimension (m)
Location
X
Y
Easting
Northing
Damhead Creek ACC
39.8
354
75
75
580967.8
172789.3
Damhead Creek HRSG
36.58
354
50
32.8
580908.4
172760.9
Damhead Creek Turbine Hall
29.5
354
134
45
580885.1
172713
Extension ACC1
40
354
65
65
581082.4
172668
Extension ACC2
40
354
65
65
581149.2
172675.8
Extension HRSG 1
40
354
20
50
581112
172805
Extension HRSG 2
40
354
50
20
581279.2
172693.6
Extension Turbine Hall 1
24
354
32
54
581111.8
172750.2
Extension Turbine Hall 2
24
354
54
32
581226.8
172682
Kingsnorth 6 boiler
110
356.5
30
52
581035.6
172535.5
Kingsnorth 6 boiler (West)
40
356.5
27
52
581013
172440.7
Kingsnorth 6 boiler (East)
60
356.5
10
52
581065.5
172537.6
Kingsnorth 5 boiler
110
356.5
30
52
581039.8
172442
Kingsnorth 5 boiler (West)
40
356.5
27
52
581007.8
172533.9
Kingsnorth 5 boiler (East)
60
356.5
10
52
581070
172443.9
Kingsnorth 3-4 Boiler (West)
60
356.5
45
105
581049.3
172067.4
Kingsnorth 3-4 Boiler (East)
40
356.5
10
105
581094.5
172070
Kingsnorth 1-2 Boiler (West)
60
356.5
45
105
581057.7
171932.5
Kingsnorth 1-2 Boiler (East)
40
356.5
10
105
581102.8
171935.2
Gypsum store
40
-
d = 14 m
581239.9
172590.9
Limestone store
40
-
d = 14 m
581275.9
172592.6
FGD associated building
40
-
d = 10 m
581154.2
172609.8
June 2009
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AIR QUALITY
10.6.50
The AERMOD model calculates time averaged ground level concentrations at any
identified specific point. The study used a 20 km by 20 km Cartesian grid with
1000 m spacing and a 2 km by 2 km Cartesian grid with 100 m spacing to predict the
ground level concentrations associated with the scenarios identified. This grid was
centred on the Damhead Creek 2 site centre (581077, 172792).
10.6.51
The meteorological data used for this modelling exercise was that from the station at
Manston Airport. The data periods considered were the years 2001-2005 inclusive.
This meteorological data was chosen as the most recent available data in the vicinity
of the Damhead Creek 2 site. For each year the predominant wind direction was from
the southwest. The wind rose for 2001 can be seen in Figure 10.2.
10.6.52
Terrain effects generally occur when ground levels within 1 km of the stack vary by
more than a third of the stack height. For the Damhead Creek 2 site, the land does
not rise above about 20 m AOD within 1 km. Therefore, terrain data has not been
included in the dispersion modelling exercise.
Stack Height Sensitivity
10.6.53
A stack height investigation for Damhead Creek 2 stack has been undertaken to
identify the most appropriate stack height. The stack height sensitivity study
examined stack heights of 50 m, 60 m, 70 m, 75 m, 80 m and 90 m which are
considered to represent a typical range for CCGT plant in the UK. The 75 m stack
height was included as this is the height of the two stacks for the existing Damhead
Creek CCGT Power Station stack. Concentrations of NO2 were predicted for 19th
highest hour of the year as required by the AQS and the annual ground level
concentrations resulting from the operation of the new plant.
10.6.54
The stack height sensitivity study assumed that both gas turbines at Damhead Creek
2 operated at full load for 8760 hours (every hour of the year).
10.6.55
Initial modelling has suggested that the meteorological data for 2001 results in the
highest predicted concentrations therefore this has been used for detailed analysis of
the stack height. Details of the modelling input parameters for Damhead Creek 2 can
be found in Table 10.8.
TABLE 10.8: DISPERSION MODEL INPUTS
Parameter
Units
Fuel input
kg/s
NOX emission level
mg/Nm
NOX flow rate
Modelling details per gas turbine
16.8
3
50
g/s
35.8
Flue gas temperature
K
97
Actual flue gas volume
3
672.6
m /s
3
Nm /s
450.2
Oxygen content
%
11.56
Flue gas velocity
m/s
25
m
5.85
Normal flue gas flow rate
Equivalent stack diameter
NOTE emission rates and levels are referenced at 15 per cent.
10.6.56
The stacks were assumed to be located at OS grid reference 581115, 172860 for
Stack 1 and OS grid reference 581334, 172709 for Stack 2.
10.6.57
On the basis of the short term AQS objective the maximum 19th highest hourly and
annual concentrations of NO2 for each stack height, has been assessed and are
June 2009
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AIR QUALITY
shown in Table 10.9. The assessment assumes a conversion rate for NOx to NO2
based on the Jansen approach discussed in Paragraph 10.5.27 onwards.
TABLE 10.9: STACK HEIGHT SENSITIVITY FOR NO2 ( g/m3)
19th Highest hour
Annual
60
17.4
0.4
70
12.4
0.3
75
10.3
0.3
80
8.8
0.3
90
6.2
0.2
100
5.0
0.2
110
4.6
0.2
Stack height
10.6.58
The data in Table 10.9 is shown graphically in Insert 10.1 and Insert 10.2.
INSERT 10.1: STACK HEIGHT SENSITIVITY MAXIMUM 19TH HIGHEST HOURLY
NO2 ( g/m3)
Ground Level Concentration NO2 (ug/m3)
25.0
20.0
15.0
10.0
5.0
0.0
60
65
70
75
80
85
90
95
100
105
110
Stack Height (m)
10.6.59
Insert 10.1 shows that the maximum predicted 19th highest hourly concentration of
NO2 decreases for an increase in stack height. Insert 10.1 also compares the
predicted ground level concentrations against the EA threshold of significance in
Horizontal Guidance Note H1, i.e. 10 per cent of the short term AQS objective for NO2
of 200 µg/m3 showing that a stack height of even 60 m is sufficient to ensure that
ground level concentrations resulting from Damhead Creek 2 are below the EA’s
significance threshold.
June 2009
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AIR QUALITY
INSERT 10.2: STACK HEIGHT SENSITIVITY MAXIMUM PREDICTED ANNUAL
AVERAGE NO2 ( g/m3)
Ground Level Concentration NO2 (ug/m3)
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
60
65
70
75
80
85
90
95
100
105
110
Stack Height (m)
10.6.60
Insert 10.2 shows that the maximum predicted annual average concentration of NO2
decreases with an increase in stack height. Insert 10.2 also compares the predicted
ground level concentrations (blue line) against the EA threshold of significance in
Horizontal Guidance Note H1 (red line), i.e. 1 per cent of the short term AQS objective
for NO2 of 40 µg/m3 showing that a stack height of 65 m is sufficient to ensure that
ground level concentrations of NO2 from the plant are below the EA’s significance
threshold for long term NO2.
10.6.61
Despite the modelling showing that a 65 m stack is sufficient to ensure dispersion of
the flue gases are within acceptable limits it is considered that there is some merit in
building in an additional factor of safety. For this reason and for consistency with the
existing Damhead Creek CCGT Power Station, it is considered that there is merit in
utilizing two 75 m stack for Damhead Creek 2 and it is this stack height that has been
used for the remainder of the modelling undertaken.
Detailed Dispersion Modelling
10.6.62
Following the stack height determination study, a full dispersion modelling exercise
using the preferred stack height of 75 m and the meteorological data for the years
2001 to 2005 inclusive was undertaken. The predicted concentrations are considered
to be the likely worst case as base load operation is assumed when Damhead Creek
2 may actually run at various loading regimes (including two shifting). The effect of
this on predicted concentrations of NO2 will be to lower the long term average, as
Damhead Creek 2 is operating less, and also to potentially lower the maximum
predicted short term averages, as Damhead Creek 2 may not operate during the
meteorological conditions leading to peak concentrations.
10.6.63
In the case of annual average concentrations, these are calculated on the basis of
Damhead Creek 2 operating for 8760 hours per year at full load. This is considered
to be an upper parameter scenario, as Damhead Creek 2 will require outage periods
for routine annual maintenance, also as noted above it is possible that Damhead
Creek 2 will two shift. A more likely operating scenario would be of the order of up to
93 per cent annual operation at varying loads.
June 2009
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Modelling Results
10.6.64
A conservative view of the operation of Damhead Creek 2 has been adopted in the
modelling so that a likely “worst case” is presented. The purpose of using this
approach is to ensure that the upper parameter of predicted impacts within the
potential operating regime of Damhead Creek 2 is considered. This ensures that
there is a “factor of safety” built into the air quality assessment. The results of the
modelling have been compared to AQS objectives.
10.6.65
Table 10.10 presents the likely worse case ground level concentrations predicted by
the dispersion modelling for the pollutants considered for Damhead Creek 2 in
isolation. The table also shows the relevant UK guidelines and reports the location
and direction of the maximum predicted. The table indicates the meteorological data
year for which the maximum was observed. Isopleths have been prepared showing
the increments to annual average NO2 concentrations and the maximum 19th highest
hourly increments to NO2 concentrations. These are presented as Figures 10.3 and
10.4 in Volume 3 of the ES.
TABLE 10.10: GROUND LEVEL CONCENTRATIONS NO2 DUE TO DAMHEAD
CREEK 2 PLANT IN ISOLATION ( g/m3)
Averaging
period
Increment to ground
level concentrations
Guideline
Distance (km)
Direction
(degrees)
Year
0.4
40
2.2
63
2002
10.3
200
2.2
63
2001
Annual
th
19 highest hour
average
Monitoring Stations and AQMA
10.6.66
The modelling undertaken above included modelling to identify predicted impacts at
some of the ambient air quality monitoring locations and AQMA identified in
Paragraph 10.4.7. The results are provided in Table 10.11 and Table 10.12 for the
19th highest hour.
TABLE 10.11: GROUND LEVEL CONCENTRATIONS NO2 AT LOCAL AIR
QUALITY MONITORING LOCATIONS ( g/m3)
19th Highest Hour
Annual
High Street ,Rainham
4.6
0.1
Long Catlis Road Gillingham
4.2
0.1
Luton Road Chatham
3.6
0.1
Pier Road Strand Gillingham
3.0
0.1
Stoke Primary School Rochester
3.6
0.1
Gillingham Gate, Gillingham
3.4
0.1
Lower Stoke A228 Rochester
5.3
0.2
Rochester monitoring station
6.3
0.2
Strand monitoring station
2.9
0.1
Location
June 2009
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TABLE 10.12: GROUND LEVEL CONCENTRATIONS NO2 AT AQMA ( g/m3)
19th Highest Hour
Annual
Chatham Centre
3.8
0.1
Cuxton Road
3.1
0.0
Frindsbury Road
2.9
0.1
Maidstone Road
3.9
0.1
Rochester Centre
3.0
0.1
Strood Centre
3.0
0.0
Location
Analysis of Results
10.6.67
The results of the modelling have been compared to appropriate objectives. Key
findings from the analysis are:
NO2. The predicted maximum long-term NO2 concentration due to Damhead
Creek 2 is predicted to be 0.4 g/m3, well within the long term AQS objective of
40 µg/m3. The maximum concentration occurs at a point just over 2.2 km to the
north east of the Damhead Creek 2 site in the vicinity of Stoke Saltings just off
the coast of Stoke.
The predicted maximum increase in short term NO2 concentrations due to the
3
operation of Damhead Creek 2 in isolation is just 10.3 g/m , which is just over
5 per cent of the AQS objective. The maximum concentration as with the annual
average occurs at a point just over 2.2 km to the north east of the Damhead
Creek 2 site in the vicinity of Stoke Saltings just off the coast of Stoke.
The plant will not significantly increase ground level concentrations of NO2 at the
various AQMA’s in the area. In addition, when considered along with the existing
ground level concentrations in the surrounding area it is not considered that
Damhead Creek 2 will give rise to any additional exceedances of any of the
relevant AQS objectives.
10.6.68
It is important to consider the findings of the modelling assessment with the existing
ambient air quality recorded in the vicinity of Damhead Creek 2.
10.6.69
It should be noted that the contribution to ground level concentrations of pollutants
from Damhead Creek 2 cannot simply be added to those for the existing sources in
the area since in many instances the location of and prevailing weather conditions of
the two maximums will be different. In the case of the existing Damhead Creek
CCGT Power Station, contributions will already be included in the background.
10.6.70
With regard to the occurrence of long term maxima from the various types of sources
the likelihood of them coinciding is high. This is due to the long averaging periods
and the variation in meteorological conditions over the averaging period.
10.6.71
When the various annual back ground concentrations in the area of Damhead
Creek 2 are considered in addition to those predicted by the modelling for Damhead
Creek 2, it can clearly be seen that Damhead Creek 2 will have a negligible effect on
air quality and should not lead to any additional exceedances of the AQS objectives.
Using the NETCEN 2010 predictions for NO2 concentrations it can be predicted that
in the likely worst case scenario Damhead Creek 2 will increase annual ground level
concentrations of NO2 from 23.0 g/m3 to 23.4 g/m3 meaning that at the likely worst
case peak annual ground level concentration should not come close to the 40 g/m 3
objective of the AQS. Peak concentrations in areas where there are existing AQMAs
June 2009
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AIR QUALITY
will be insignificant and should not serve to prolong the designation of these areas as
AQMAs as Medway Council endeavours to reduce NO2 concentrations at these sites.
10.6.72
For short term averaging periods there is less likely to be such a coincidence of
contributions from several sources. This is due to the weather conditions associated
with the maximum from each type of source. Plumes from point sources, such as
power station or boiler plumes, generally provide a maximum increment to ground
level concentrations when the weather conditions are warm and/or windy. Conversely
the maximums associated with line sources, roads, occur when it is calm, cold and
there is a low level inversion. During these times the thermally buoyant plume from a
point source will burst through the inversion layer and disperse over a larger area.
The inversion layer will severely limit the ability of the plume to ground, once the
plume is above it. Therefore the maximum short term concentrations from each
source type will not coincide and there will not be a summation combination of the
effects of each. It is not therefore reasonable to sum the maximum contribution to
ground level concentrations due to Damhead Creek 2 in isolation with the existing
monitored background level for short term concentrations.
10.6.73
Damhead Creek 2 maximum short term concentrations will be a small percentage of
the standard and will occur at times when contributions from other sources are low.
Thus there will be no risk of generating any exceedance of the short term standard
and affecting whether the short term objective is achieved. Even if the likely worst
case contribution predicted for Damhead Creek 2 is added to the likely worst case
recorded 19th highest hourly back ground of 99 g/m3 recorded at Strand (Gillingham)
in 2004 the resulting concentration would not even come close to exceeding the AQS
objective of 200 µg/m3.
10.6.74
The emissions from Damhead Creek 2 during operation will not impact significantly on
local air quality and will not lead to an exceedance of any of the AQS objectives. In
addition there are no predictions in excess of the thresholds of significance derived
from Environment Agency guidance note H1. It can therefore be concluded that
Damhead Creek 2 will not have a significant impact on air quality with regard to short
or long term ground level concentrations of NO2.
10.6.75
The location of maximum increments is indicative of the prevailing meteorological
conditions, i.e. predominantly south/south-westerly winds.
10.6.76
In practice, the predicted small increments to annual average levels due to Damhead
Creek 2 would be virtually undetectable using diffusion tubes or other monitoring
equipment in use today.
10.6.77
The phasing or otherwise of the Damhead Creek 2 development will have little effect
on the impact to air quality of the project. The only effect that is envisaged would be
minor amounts of dust creation over a longer period where a two phased construction
phase is required.
10.7
Mitigation Measures and Monitoring Programmes
Construction
10.7.1
Good site management practices during the construction works will help to prevent
the generation of airborne dust.
ScottishPower will require its construction
contractors to take sufficient precautionary measures to limit dust generation.
10.7.2
To ensure that atmospheric dust, contaminants or dust deposits generated by the
construction do not exceed levels which could constitute a health hazard or nuisance
to those persons working at the existing Damhead Creek CCGT Power Station, on
the Damhead Creek 2 site or living nearby a dust monitoring programme will be
carried out throughout the construction period. It is proposed that environmental
monitoring of dust be carried out at areas of excavation, the stockpiles, and various
additional locations across the Damhead Creek 2 site and at locations on the site
June 2009
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boundary. A trained and competent person will carry out monitoring on a weekly
basis. If dry windy weather prevails then the rate of monitoring will be increased. An
aerosol monitoring system will be used. The results will be checked against Table
10.13.
TABLE 10.13: MAXIMUM ALLOWABLE EXPOSURE LEVELS
Monitoring
location
Dust
Aerosol monitoring system
(directional, with
instantaneous read-out)
Level
Action
>1 and <5 mg/m3
Review PPE* level if >1 mg/m 3
>5 mg/m3
continuously
Stop work in breathing zone
Identify cause and carry out remedial
work
Review PPE level, go to level 2
respiratory protection
Monitor every 30 minutes
Site perimeter
0.2 mg/m3
Stop work
work
Site wide
Excessive dust or
odour
Further monitoring or control
measures as appropriate. All such
instances to be logged
Excavation areas
Stockpiles
Environmental Dust
Sampler (gravimetric over
fixed time period)
Visual and odour checks
*PPE - Personal protection equipment.
10.7.3
If the above values are exceeded then the rate of monitoring will be increased to four
times a day or to a level consistent with the results that have been logged and
additional remedial action as described below will be taken.
10.7.4
If a potential for dust emissions exists, for example on dry windy days, then the
following procedure will be followed:
Materials will be assessed for moisture content;
If material is dry then water will be sprayed on to the working area to suppress
dust;
Excavation faces not being worked will, if required, be either sheeted or treated
with a chemical dust suppressant; and
All operatives working in areas of potential dust emission will be provided with
paper type face masks.
10.7.5
Materials deposited on stockpiles on the Damhead Creek 2 site will be closely
monitored for any possible emission of dust and if required they will be damped down,
covered or treated with a dust suppressant.
10.7.6
If finely ground materials are delivered, these should be in bag form or stockpiled in
specified locations where the material can be suitably covered.
10.7.7
All vehicles carrying bulk materials into or out of the Damhead Creek 2 site will be
covered to prevent dust emission. Minimum drop heights will be used during material
transfer.
10.7.8
Dust emission from moving construction plant and site transport will be mitigated by
the use of water bowsers, which will dampen all movement areas being utilized by
traffic.
June 2009
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10.7.9
A wheel washing facility will be provided adjacent to the Damhead Creek 2 site exit
and will be used by all heavy commercial vehicles leaving the Damhead Creek 2 site,
preventing the transmission of soil from the Damhead Creek 2 site to the public
highway.
10.7.10
Also a road sweeping vehicle will be employed when required during the construction
period to remove dust and dirt from all the public roads.
10.7.11
The above measures may only be necessary should the activities leading to the
greatest dust generation occur during a dry period.
10.7.12
If care is taken dust emissions will not impact on local air quality.
Operation
10.7.13
The following mitigating measures have been included in the design of Damhead
Creek 2:
The use of DLN Burners, which ensures NOx levels to be in accordance with
LCPD requirements;
The use of a fuel inherently low in sulphur; and
A stack of sufficient height and flue gases of sufficient temperature and velocity
to ensure good dispersion.
10.7.14
These measures, in combination, result in limited increases in background
concentrations of oxides of nitrogen, no emissions of particulates and negligible
emissions of sulphur dioxide, such that no further measures are deemed necessary.
10.7.15
ScottishPower will require a manufacturer’s guarantee in place to guarantee the
performance of the NOx abatement system. If NOx values are out with the guarantee
value the operation and calibration of the instrument will be checked and, if proved to
be accurate, Damhead Creek 2 will be examined and the fault corrected.
10.7.16
ScottishPower would if requested monitor ground level concentrations of NOx during
the first year of Damhead Creek 2's operation and one year beforehand. This monitor
should confirm the results of the atmospheric modelling and that the impacts of the
emissions from Damhead Creek 2 are in fact acceptable.
10.7.17
Emissions will be controlled during operation in accordance with the manufacturer’s
recommendations and the limits and conditions specified in the EPR permit for the
process, taking account of the technical guidance available for this type of plant.
10.7.18
The stacks will be fitted with a continuous NOx and CO monitor. The measured value
will be recorded and displayed in the Control Room. Routine calibration checks will
be carried out as recommended by the manufacturer and as agreed with the EA. Any
other ad-hoc calibration checks required by the EA will be carried out. An oxygen
monitor will also be supplied and results from this will be used to correct the NO x
measured value to the format required by the EA. Either a moisture meter will be
provided or a mathematical correction factor based on combustion of natural gas will
be used to convert to the dry condition. The results from this stack monitoring will be
available to the public in the Public Register held by the EA.
10.7.19
Sampling points and safe access adjacent to the continuous monitoring points will be
installed.
10.7.20
Regular observation of chimney emissions will also be made.
10.8
10.8.1
The inherent mitigation included in Damhead Creek 2 design has been proven to be
sufficient to the extent that additional mitigation measures for the control of emissions
is not required.
June 2009
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10.9
10.9.1
The plant has the potential to give rise to cumulative impacts with regard to the
existing Damhead Creek and Kingsnorth Power Stations and the potential future
construction and operation of both the Kingsnorth Business Park and the proposed
Kingsnorth power Station Units 5 and 6.
Construction
10.9.2
The nature of any construction phase impacts are easily established but difficult to
quantify with any degree of certainty given that the construction programmes for both
the Kingsnorth Business Park and Kingsnorth Power Stations Units 5 and 6 are open
to change.
10.9.3
For the purposes of the assessment it has been assumed that the construction of the
Kingsnorth Power Station will commence in 2013 and will be completed in 2018. The
construction of the Kingsnorth Business Park is likely to be phased and would not
represent a substantial source of cumulative impact with regard to construction phase
air quality.
10.9.4
Given that the end of the Kingsnorth Power Station construction phase and the
earliest possible start date for the construction of Damhead Creek 2 would only
slightly overlap it is not considered that there is a risk of significant cumulative impacts
with regard to dust created by the two projects or from emissions from vehicles and
other on site construction activities. Indeed both projects are well separated from
nearby residences such that, with proper mitigation employed, impacts will be
insignificant even were the two project schedules to entirely overlap.
Operation
10.9.5
As with construction phase impacts, any operational cumulative impacts are very
much subject to the schedules of other projects, which ultimately may or may not be
progressed. There are, therefore, a number of cumulative impact scenarios that must
be considered for the purposes of the EIA for Damhead Creek 2.
10.9.6
The proposed Kingsnorth Power Station Units 5 and 6 were due to commence
operation in 2013. However, this is unlikely at the time of writing as E.ON have
requested that any Section 36 consent for the project be put on hold until such a time
as the results of the DECC’s Carbon Capture and Storage project competition are
known. As the potential exists for Damhead Creek 2 to operate in conjunction with
the Kingsnorth Units 5 and 6 development at some stage in the future this eventuality
has been considered and is discussed further below.
10.9.7
There are potential cumulative impacts with the proposed operation of the Kingsnorth
Business Park which may include a small biomass boiler(s). The impacts of this
boiler(s) would be negligible and almost entirely restricted to the Kingsnorth Business
Park site due to the size of the plant. For this reason the boiler(s) has not been
included in the modelling undertaken.
10.9.8
The potential does not exist that Damhead Creek 2 will operate in conjunction with the
existing Kingsnorth Power Station Units 1 to 4. The Kingsnorth plant opted out of the
LCPD and is therefore due to close by 2016. Cumulative effects of the existing
Kingsnorth plant operating in conjunction with the existing Damhead Creek CCGT
Power Station and Damhead Creek 2 are therefore not necessary.
10.9.9
If none of the other projects proposed in the area were to be progressed and the
Kingsnorth Units 1 to 4 were decommissioned then Damhead Creek 2 would operate
in conjunction with the existing Damhead Creek CCGT Power Station only. No matter
which of the various other plants are in operation the existing Damhead Creek CCGT
Power Station will remain in operation throughout the majority of the life time of
Damhead Creek 2 and should therefore be considered along with any other possible
cumulative impact scenario.
June 2009
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10.9.10
The following scenarios have been modelled with a summary of the modelling
findings presented below:
Scenario 1: Damhead Creek 2 operating with the existing Damhead Creek
CCGT Power Station
Scenario 2: Damhead Creek 2 operating with Kingsnorth Units 5 and 6 and the
existing Damhead Creek CCGT Power Station
10.9.11
In all cases full load operation is assumed for 8760 hours per year.
Dispersion Modelling of Cumulative Impacts
10.9.12
A dispersion modelling exercise has been undertaken for the scenarios identified as
being of interest. Table 10.14 shows the data used in the dispersion calculations for
the modelling whilst Table 10.15 provides details of stack co-ordinates. Building
inputs are as per Table 10.7.
10.9.13
The inputs are taken from as built drawings of the existing Damhead Creek CCGT
Power Station with the Kingsnorth coordinates taken from those quoted by Kingsnorth
in their Environmental Statement (ES) for the proposed Kingsnorth Units 5-6. With
regard to the Kingsnorth coordinates, these have been slightly corrected for building
orientation to better relate to the plans submitted by E.ON which showed that the
plant was not quite on a north south axis as had been identified in the ES. Building
dimensions have been taken from as built drawings for the existing Damhead Creek
CCGT Power Station and from the proposed layout in the environmental statement for
the proposed Kingsnorth Units 5-6.
TABLE 10.14: DISPERSION MODELLING INPUT DATA (PER UNIT)
Parameter
Damhead Creek
Kingsnorth 5-6
g/s
34.18
122
Flue gas temperature
C
120
80
Stack diameter
m
6.1
6.6
m/s
28.8
24.8
3
m /s
842
848
m
75
198
NOX flow rate
Flue gas velocity
Actual flue gas flow rate
Stack height
TABLE 10.15: STACK COORDINATES
Stack
X
Y
Damhead Creek (stack 1)
580927.2
172790.1
Damhead Creek (stack 2)
580952.8
172791.8
Kingsnorth Unit 5
581181.2
172442.7
Kingsnorth Unit 6
581173
172602
Scenario 1 –Damhead Creek 2 operating with the existing Damhead Creek
CCGT Power Station
10.9.14
Table 10.16 presents the likely worst case ground level concentrations predicted by
the dispersion modelling for the pollutants considered for the operation of Damhead
Creek 2 in conjunction with the existing Damhead Creek CCGT Power Station. The
table also shows the relevant UK guidelines and reports the location and direction of
June 2009
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AIR QUALITY
the maximum predicted. The table indicates the meteorological data year for which
the maximum was observed. Two isopleths have been prepared: increments to
annual average NO2 concentrations and maximum 19th highest hourly increments to
NO2 concentrations. These are presented as Figures 10.5 and 10.6.
TABLE 10.16: GROUND LEVEL CONCENTRATIONS DUE TO SCENARIO 1
( g/m3)
Averaging
Period
Increment to ground
Guideline
Distance
(km)
Direction
(degrees)
Year
0.4
40
7.1
8
2005
10.9
200
2.8
45
2003
Annual
th
19 Highest
Hourly
Monitoring Stations and AQMA
10.9.15
Paragraph 10.4.7. Table 10.17 and Table 10.18 provide the results of this modelling.
19th Highest Hour
Annual
7.7
0.2
6.8
0.1
Luton Road Chatham
6.5
0.1
5.5
0.1
7.0
0.1
5.5
0.1
8.9
0.3
11.1
0.3
5.8
0.1
Location
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19th Highest Hour
Annual
Chatham Centre
7.3
0.1
Cuxton Road
5.6
0.1
Frindsbury Road
5.2
0.1
Maidstone Road
7.3
0.1
Rochester Centre
5.6
0.1
Strood Centre
5.0
0.1
Location
Analysis of Results
10.9.16
NO2 in conjunction with the existing Damhead Creek CCGT Power Station. The
predicted maximum long-term NO2 concentration due to two plants is 0.4 g/m 3,
well within the long term AQS objective of 40 µg/m3. The maximum
concentration occurs at a point just over 7 km to the north of the Damhead
Creek 2 site in the Thames Estuary.
The maximum short term NO2 concentration resulting from the two plants
3
operating in conjunction is just 10.9 g/m or just over 5 per cent of the AQS
3
objective of 200 g/m . The maximum concentration occurs at a point just over
2.8 km to the east of the Damhead Creek 2 site in the vicinity of Stoke Saltings
just off the coast of Stoke.
The two plants will not significantly increase ground level concentrations of NO2
at the various AQMA designated in the surrounding area. In addition when
considered along with the existing ground level concentrations in the area it is
not considered that the plant will give rise to any additional exceedances of any
of the relevant AQS objectives.
The two plants will not in isolation generate any exceedances of the long or short
term AQS objective for NO2 and will lead to insignificant releases of NO2 due to
the inherently clean nature of the fuel.
Scenario 2 – Damhead Creek 2 operating in conjunction with the existing
Damhead Creek CCGT Power Station and Kingsnorth Units 5 and 6
10.9.17
Table 10.19 presents the likely worst case ground level concentrations predicted by
the dispersion modelling for the pollutants considered for the operation of Damhead
Creek 2 in conjunction with the existing Damhead Creek CCGT Power Station and
the proposed Kingsnorth Units 5 and 6. The table also shows the relevant UK
guidelines and reports the location and direction of the maximum predicted. The table
indicates the meteorological data year for which the maximum was observed. Two
isopleths have been prepared: increments to annual average NO2 concentrations and
maximum 19th highest hourly increments to NO2 concentrations. These are presented
as Figures 10.7 and 10.8.
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TABLE 10.19: GROUND LEVEL CONCENTRATIONS DUE TO SCENARIO 2
( g/m3)
Averaging
Period
Increment to ground
Guideline
Distance
(km)
Direction
(degrees)
Year
0.8
40
2.8
45
2005
29.6
200
7.1
8
2004
Annual
th
19 Highest
Hourly
Monitoring stations and AQMA
10.9.18
Paragraph 10.4.7 and Table 10.20 and Table 10.21 provide the results of this
modelling.
19th Highest Hour
Annual
20.9
0.4
18.7
0.4
Luton Road Chatham
16.1
0.3
13.7
0.3
16.5
0.3
16.2
0.3
14.9
0.7
19.8
0.7
12.8
0.3
Location
19th Highest Hour
Annual
Chatham Centre
16.7
0.3
Cuxton Road
13.3
0.2
Frindsbury Road
11.6
0.2
Maidstone Road
15.5
0.3
Rochester Centre
12.4
0.2
Strood Centre
11.7
0.2
Location
Analysis of Results
10.9.19
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NO2 in conjunction with the existing Damhead Creek CCGT Power Station and
proposed Kingsnorth Units 5 and 6. The predicted maximum long-term NO2
concentration due to plants is 0.8 g/m3, well within the long term AQS objective
of 40 µg/m3. The maximum concentration occurs at a point just over 2.2 km to
the north east of the Damhead Creek 2 site in the vicinity of Stoke Saltings just
off the coast of Stoke.
The maximum short term NO2 concentration resulting from the plants operating
3
3
in conjunction is 29.6 g/m or 15 per cent of the AQS objective of 200 g/m .
The maximum concentration occurs at a point just over 7 km to the north of the
Damhead Creek 2 site in the southern most area of the Thames Estuary.
The three plants will not significantly increase ground level concentrations of NO2
at the various AQMA designated in the surrounding area. In addition when
considered along with the existing ground level concentrations in the area it is
not considered that the plant will give rise to any additional exceedances of any
of the relevant AQS objectives.
The plants will not in isolation generate any exceedances of the long or short
term AQS objective for NO2 and will lead to insignificant releases of NO2.
Summary of Cumulative Operational Impacts
10.9.20
The cumulative impacts with regard to the various operational scenarios considered
are considered to have demonstrated that Damhead Creek 2 will not give rise to
significant cumulative environmental effects with regard to simultaneous operation of
Damhead Creek 2 in conjunction with either the existing Damhead Creek CCGT
Power Station or the proposed Kingsnorth units 5 and 6.
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SECTION 11
NOISE AND VIBRATION
11
NOISE AND VIBRATION
11.1
Summary
11.1.1
The nearest residential and sensitive areas are the Market Garden/Dog Kennels,
approximately 1 km to the north east and Whitehall Farm, approximately 1.1 km north
of the Damhead Creek 2 site.
11.1.2
The impact of construction noise is not predicted to be significant due to the distances
between the proposed construction site and the noise sensitive locations, and due to
the temporary and changing nature of the noise source.
11.1.3
Environmental noise levels have been predicted for Damhead Creek 2 based upon
test data for similar units. Noise control treatment will be introduced due to the
proximity of residential areas around the Damhead Creek 2 site. The impact of
predicted operational noise has been assessed for Damhead Creek 2 alone, and for
the cumulative impact of the plant operating together with the existing Damhead
Creek CCGT Power Station and the proposed Kingsnorth Units 5 and 6. In both
cases, it is not predicted that complaints will be likely at any Noise Sensitive Receptor
(NSR) location.
11.1.4
An assessment of the noise impact of Damhead Creek 2, and the subsequent
likelihood of complaints, has been completed in accordance with procedures outlined
in BS 4142:1997 “Method of Rating Industrial Noise Affecting Mixed Residential and
Industrial Areas”.
11.1.5
The residential positions chosen for the evaluation have been agreed with an
Environmental Health Officer (EHO) from Medway Council, and measurements have
been made of background noise levels during the most sensitive night-time period.
11.1.6
The level of noise control that will be provided on Damhead Creek 2 is extensive and
has been based on achieving the appropriate limits. This will result in no significant
noise impact due to the construction or operation of Damhead Creek 2. There will be
no impact due to operational vibration with some minimal vibration associated with
piling during construction.
11.1.7
The gas turbines and steam turbine equipment are the most significant sources of
noise generation associated with the proposed Development. The gas turbines will
be contained within acoustic enclosures in order to attenuate the noise. It is
envisaged that the area of the building containing the steam turbine equipment will be
acoustically treated.
11.1.8
With suitable noise attenuation it is envisaged that the proposed Development will not
lead to a perceptible increase in noise at the noise sensitive receptors.
11.2
Introduction
11.2.1
This Section presents the noise and vibration impact assessment, and includes the
assessment methodology and significance criteria adopted in undertaking the
assessment; the baseline conditions on which the developments impact is assessed;
the potential (pre-mitigation) significant environmental impacts which the
Development may have; the mitigation measures to be adopted; and the resultant
residual (post-mitigation) significant impacts of the construction and operation of the
development. Cumulative residual impacts are also considered within this Section.
11.2.2
Consultations undertaken with Medway Council as part of this noise and vibration
impact assessment have informed the assessment methodology and impact
assessment, the key considerations being:
Establishment of background noise levels.
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NOISE AND VIBRATION
Prediction and assessment of operational noise and vibration against lowest
measured background levels.
11.3
11.3.1
full transcript of these policies is contained in Volume 2, Appendix B.
NRM10
Noise
NR5
Pollution Impacts
BNE2
BNE3
11.4
Amenity Protection
Noise Standards
Assessment Methodology
11.4.1
The noise impact assessment has focussed on nine NSRs which are identified in
Table 11.1. Existing baseline conditions at each NSR have been determined by way
of an attended noise survey. The results of this survey have then been correlated
with operating conditions at Kingsnorth and the existing Damhead Creek CCGT
Power Station.
11.4.2
Due to the varying influence of local power sources, a review of other surveys
undertaken in the area has also been undertaken to obtain the lowest background
noise levels at each NSR. This is presented in Section 11.5.
11.4.3
A prediction of the impact during construction has been undertaken using the
methodology contained within BS 5228, and information regarding the noise output of
specific items of plant contained therein. The operational noise levels have been
predicted at all NSRs using a computerized 3D noise propagation model that
incorporates typical sound power data for the proposed plant items. The model takes
account of screening effects of existing and proposed plant items. The significance of
the predicted impact has been determined using the semantics of BS 4142.
11.4.4
The full details of the assessment methodology are presented in the Baseline Noise
Report. This is provided in Volume 2, Appendix F.
Legislative Framework
11.4.5
The following legislative guidance is used for the assessment:
BS 4142:1997 ‘Method for rating industrial noise affecting mixed residential and
industrial areas,’ BSI
BS 7445: 1991 'Description and Measurement of Environmental Noise' Parts 1 to
3, BSI
BS 5228: 1997 'Noise and vibration control on construction and open sites' Parts 1
to 4, BSI
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NOISE AND VIBRATION
11.4.6
BS 4142 ‘Method for rating industrial noise affecting mixed residential and industrial
areas' offers guidance on the assessment of industrial and commercial noise affecting
residential and industrial areas. It describes a method for assessing whether
industrial noise is likely to result in complaints from nearby residents.
11.4.7
BS 7445 'Description and Measurement of Environmental Noise' defines and
prescribes best practice during recording and reporting of environmental noise. It is
inherently applied in all instances when making environmental noise measurements.
11.4.8
BS 5228 'Noise and vibration control on construction and open sites' gives
recommendations for basic methods of noise and vibration control relating to
construction sites and other open sites where construction activities are carried out. It
offers a methodology for predicting noise levels from construction sites.
11.4.9
BS 4142 provides a methodology for the assessment of industrial noise in mixed
residential and industrial areas. In this case, the standard suggests obtaining an
assessment level by comparing the existing background noise levels with the 'rating
level', which is the predicted noise output of the proposed plant, corrected to account
for any acoustic features such as tonal or impulsive noises. The semantics used for
assessing the likelihood of complaints due to the introduction of a new industrial noise
source are as follows:
When subtracting the background level from the rating level, the greater the
difference, the greater the likelihood of complaints.
A difference of around +10 dB or more indicates that complaints are likely.
A difference of around +5 dB is of marginal significance.
If the rating level is more than 10 dB below the measured background noise level
then this is a positive indication that complaints are unlikely.
11.5
Noise Sensitive Receptors
11.5.1
This assessment considers the noise impact on a number of NSRs. The locations of
these were agreed during consultation with Medway District Council. Descriptions of
the NSRs are provided in Table11.2.
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TABLE 11.1: NOISE SENSITIVE RECEPTOR DESCRIPTIONS
Location
Description
1
Residential property Tudor Farm, approximately 1.8 km north north-east of the centre of the
proposed Development. Monitoring took place at the corner on the south side of the property
nearest to Stoke Road.
2
Residential property Polly Adams Cottage, approximately 1.2 km north north-east of the
centre of the proposed Development. Monitoring took place to the north side of the cottage.
3
Residential property Riverview Cottage, approximately 1.4 km north of the centre of the
proposed Development.
4
Whitehall Farm, approximately 1.1 km north of the proposed Development.
5
Residential properties on Stoke Road near to lane leading to Whitehall Farm, approximately
1.3 km north north-west of the centre of the proposed Development.
6
Beluncle Farm and surrounding residential properties, approximately 1.2 km from the centre
of the proposed Development.
7
Sturdee Cottages, approximately 1.9 km from the centre of the proposed Development.
8
Eschol Lane/Jacobs Lane, approximately 1.3 km from the centre of the proposed
Development.
9
Nature Study Area approximately 1 km from the centre of the proposed Development.
10
Market Garden/Dog Kennels, approximately 1 km from the centre of the proposed
Development.
11.5.2
The distances quoted previously are taken from the approximate centre of the
proposed Development site. Figure 11.1 shows these locations in relation to the
Damhead Creek 2 site.
Baseline Conditions
11.5.3
The full details of the noise measurements undertaken by PB for the purposes of this
ES are detailed in a Baseline Noise Report. This is provided in Volume 2,
Appendix F. In addition, the time history of the LA90 and LAeq parameters (which are
parameters for measurement of background noise) from the long-term measurement
position are represented graphically in Appendix F.
11.5.4
It can be see from the Baseline Noise Report in Volume 2, Appendix F that the noise
levels at the permanent measurement position strongly correlate with the power
output from the existing Damhead Creek CCGT Power Station and Kingsnorth Power
Station. Therefore, the local power generation sources are significant contributors to
the background noise levels at local NSRs.
Additional Surveys undertaken by Others
11.5.5
Various other noise surveys have recently been undertaken in the vicinity of the
existing Damhead Creek CCGT Power Station. These are summarised below in
Table 11.2
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TABLE 11.2: SUMMARY OF NOISE SURVEYS RECENTLY UNDERTAKEN
AROUND DAMHEAD CREEK
Purpose of
Survey
Date
of
Survey
Type and
Duration of
Measurement
Kingsnorth
Units 5 & 6
6-7
July
2006
Not Known
17 - 22
Oct
2007
29 - 30
Nov
2007
ES
Kingsnorth
Business
Park
ES
Damhead
Creek 2
Investigations
Night-time Minimum Electrical Power Output
Damhead
Creek
Kingsnorth
Unit 1
Kingsnorth
Unit 2
Kingsnorth
Unit 3
Kingsnorth
Unit 4
0 MW
270 MW
230 MW
230 MW
440 MW
Continuous
measurement
of LA90,1hour
values over
five nights
500 MW
230 MW
0 MW
230 MW
230 MW
LA90,10 m spot
measurements,
undertaken in
circuits through
the night
500 MW
430 MW
300 MW
480 MW
230 MW
11.5.6
As Table 11.2 shows, each survey has been undertaken with the existing generation
facilities at the existing Damhead Creek CCGT Power Station and Kingsnorth Units 14 under different operating conditions.
11.5.7
Table 11.3 summarises the lowest LA90 recorded during each survey at each
measurement position during the night. In terms of this Section, night measurements
were taken between 00:00 and 05:00.
TABLE 11.3: SUMMARY OF LOWEST NIGHT TIME LA90 LEVELS MEASURED
DURING VARIOUS SURVEYS
Location
Lowest Measured LA90,T
Location Description
Kingsnorth
Units 5 & 6
Kingsnorth
Business Park
Damhead
Creek 2
ES
ES
Investigations
Lowest from
All Surveys
1
Tudor Farm
Not Measured
29
36
29
2
Polly Adams Cottage
Not Measured
29
37
29
3
Riverview Cottage
Not Measured
27
35
27
4
Whitehall Farm
Not Measured
31
Not Measured
31
5
Tunbridge Hill
36
Not Measured
37
36
6
Beluncle Farm
32
Not Measured
35
32
7
Sturdee Cottages
Not Measured
Not Measured
33
33
8
Eschol Lane/Jacobs
Lane
33
Not Measured
33
33
9
Nature Study Area
Not Measured
Not Measured
35
35
10
Market Garden/Dog
Kennels
38
Not Measured
38
38
11.5.8
For the purposes of deriving operational impact, the lowest measured LA90 from all
surveys shall be used to represent the baseline noise environment for the purposes of
this ES. This will ensure that the assessment represents the likely worst case, i.e.
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NOISE AND VIBRATION
typical operation of proposed plant will be assessed against background noise
measured during periods of low activity from existing power facilities.
11.6
Potential Impacts
Construction
Noise
11.6.1
Construction activity inevitably leads to some degree of noise disturbance at locations
in close proximity to the construction activities. It is however a temporary source of
noise. The noise levels generated by construction activities would have the potential
to impact upon nearby noise sensitive receptors. Noise levels at any one location will
vary as different combinations of plant machinery are used, and throughout the
construction of the proposed plant as the construction activities and locations change.
However, these would depend upon a number of variables, the most significant of
which include the following:
The noise generated by plant or equipment used on site, generally expressed as
sound power levels;
The periods of time construction plant is operational;
The distance between the noise source and the receptor; and
The level of attenuation likely due to ground absorption, air absorption and
barrier effects.
11.6.2
In the absence of specific information regarding the proposed construction plant and
activities, it is possible to assess the potential construction noise impacts using the
methodology set out in BS 5228 in conjunction with general information regarding
proposed activities.
11.6.3
Department for Environment (DoE) Advisory Leaflet (AL) 72 gives advice as to
maximum levels of construction site noise at residential locations during daytime
hours. The leaflet states that the noise level outside the nearest occupied room
should not exceed 70 dB(A) in rural, suburban and urban areas away from main road
traffic and industrial noise. This increases to 75 dB(A) for urban areas near to main
roads.
11.6.4
In 2005, the Department for Environment, Food and Rural Affairs (DEFRA) published
an Update of Noise Levels for the Prediction of Noise on Construction and Open
Sites. This has been used to supplement the database contained in BS 5228. Table
11.4 shows the noise levels associated with typical construction activities, gives an
indication of the distance at which the 70 dB(A) limit proposed by the DoE would be
met, and predicts the likely noise level contributed by each item of plant at a distance
of 800 m,
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TABLE 11.4: EXAMPLE SOUND PRESSURE LEVELS ASSOCIATED WITH
TYPICAL CONSTRUCTION ACTIVITIES
Construction Activity / Associated
Plant
Typical
A-weighted
Sound Pressure
Level (LA) at 10 m
Example Distance
Required to meet
70 dB(A) Limit
Estimated Sound
Pressure Level
(LA) at 800 m
Dozer
75
18
37
Tracked Excavator
78
25
40
Wheeled Backhoe Loader
68
8
30
Dozer
81
35
43
Tracked Excavator
79
28
41
Loading Lorry
80
32
42
Articulated Dump Truck
81
35
43
Roller
79
28
41
Vibratory Plate
80
32
42
Hydraulic Hammer Rig
89
89
51
Large Rotary Bored Piling Rig
83
45
45
Welder (Welding Piles)
73
14
35
Generator for welder
57
2
19
Cutter (Cutting Piles)
68
8
30
Large Lorry Concrete Mixer
77
22
39
Concrete Pump (Discharging)
67
0
29
Tower Crane
77
22
39
Site preparation
Excavation
Rolling and compaction
Piling
Welding/cutting steel
Other
11.6.5
The estimated sound pressure levels shown are likely worst case estimates based on
propagation attenuation only, and do not consider any screening, directivity or
absorptive effects.
11.6.6
The closest residential property (Location 10) is just under 1 km from the proposed
construction site. Whilst at this time is not possible to predict an exact construction
noise level, as detailed information regarding planned construction activities are
unknown, Table 11.4 indicates that the distances involved between the proposed
Development and the nearest NSR is large enough so that the DoE level of 70 dB(A)
will be met.
11.6.7
Considering the temporary and changing nature of the proposed construction works,
the current levels of noise due to the existing power plants and adjacent roads, and
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NOISE AND VIBRATION
the large distances between the proposed construction activities and NSR locations,
the impact of construction noise is not predicted to be significant.
Vibration
11.6.8
Some construction activities can be a source of ground-borne vibration, which can be
a cause for concern at the nearest receptors. Typical activities that would lead to
vibration effects include compaction, breaking and piling.
11.6.9
BS5228 Part 4 suggests that vibration problems due to piling could potentially occur
within distances of the magnitude of 0 – 50 m. As the closest NSRs are
approximately 1km away, the level of induced vibration will not be sufficient to
propagate from the proposed site.
Operation
Predicted Operational Noise
11.6.10
Noise levels at the nearest NSRs have been calculated using a three dimensional
noise propagation model. The model has used typical sound power values
associated with Gas Generation Facilities, and has calculated the spread of noise
using the algorithms contained within ISO 9613 Part 2. Corrections have been
applied to account for:
Distance propagation;
Directivity effects; and
Screening effects due to existing buildings or plant, or other proposed on-site
structures.
11.6.11
The model is intended to provide a likely worst case assessment of the noise level
likely to be experienced at each NSR location during moderate downwind conditions.
11.6.12
A number of assumptions are made with regards to the noise control likely to be
installed on major plant items, and these are stated below.
11.6.13
The following assumptions with regards to noise control have been made:
Gas turbines are to be housed in individual acoustic enclosures.
Gas turbine filter and ventilation apertures are to be fitted with high performance
silencers, and designed such that they face towards the existing plant or towards
new plant such that all sensitive receptors benefit from screening and/or
directivity corrections.
Low noise air cooled condensers will be used.
Due to the impracticality of screening stack noise, discharge noise will be
controlled using high performance silencers tuned to attenuate low frequencies
from the gas turbine exhausts.
Unit transformers and generator transformers will be housed in an appropriate
enclosure or three sided pen, to provide full screening to noise sensitive
receptors.
All plant items shall be controlled to minimize noise of an impulsive or tonal
nature, such that the rating level as defined is BS 4142 is equal to the specific
noise level.
The model considers normal operational noise. As such, noise due to nonnormal operation plant items has not been considered.
11.6.14
The noise model has incorporated the following sound power data, which is based on
the previously described level of noise control.
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TABLE 11.5: SOUND POWER LEVELS ASSOCIATED WITH NOISE SOURCES
Noise Source
Source Sound Power
Source Height
No. off
GT Inlet Filter Aperture
96
22
2
GT Building Walls
91
23
8
GT Building Roof
89
23
2
HRSG Transition
93
10
6
HRSG Walls
90
23
4
HRSG Stack Outlet
90
75
2
Unit Transformer
93
4
6
Generator Transformer
93
4
2
Air Cooled Condenser
99
36
2
11.6.15
Figure 11.2 shows noise contours surrounding the site generated by the noise model.
Assessment of Operational Noise
11.6.16
Table 11.6 summarises the predicted ‘rating’ noise levels from the proposed plant at
each of the NSRs, and compares it with the lowest measured background level. As
the equipment will be not be running intermittently and will be of modern design, is
assumed that the noise will not contain any acoustic features, so no acoustic feature
corrections have been applied to the levels predicted.
TABLE 11.6: BS 4142 ASSESSMENT TABLE
Predicted Noise
Level due to
Proposed
Development (rating
level) (dB(A))
Lowest Measured
Night time
Background Level
LA90 (dB(A))
Excess of
Rating over
Background
Level
Tudor Farm
27.7
29
-1.3
2
Polly Adams Cottage
26.1
29
-2.9
3
Riverview Cottage
25.6
27
-1.4
4
Whitehall Farm
18.7
31
-12.3
5
Tunbridge Hill
25.5
36
-10.5
6
Beluncle Farm
26.9
32
-5.1
7
Sturdee Cottages
25.7
33
-7.3
8
Eschol Lane/Jacobs Lane
26.9
33
-6.1
9
Nature Study Area
23.3
35
-11.7
10
Market Garden/Dog Kennels
29.0
38
-9
Location
NSR Description
1
11.6.17
At NSRs 4, 5, 9 and 10 the rating level is approximately 10 dB below the lowest
measured night time background level. This represents a positive indication that
noise complaints due to the operation of the proposed Development are unlikely.
11.6.18
At NSRs 6 - 8 the rating level is approximately 5 dB below the lowest measured night
time background level. At locations 1 - 3, the rating level (from the NSR to the
proposed Development) is approximately equal to the lowest existing background
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NOISE AND VIBRATION
level. In the semantics of BS 4142, these levels are considered to be of less than
‘marginal significance’.
Operational Vibration
11.6.19
It is predicted that on site vibration sources will include the following:
Balanced rotating equipment, such as turbines; and
Wind induced vibrations in the stacks and condenser structures, to be
transmitted to the foundations.
11.6.20
As all rotating machinery is to be located on massive foundations, any transmitted
vibration into the ground will be minimal, and there are no structures whose design
would result in undue wind induced vibration. It is not therefore anticipated that the
level of induced vibration will be sufficient to propagate to the nearest sensitive
receptors over the distances involved. Hence the impact of operational vibration is
not assessed further.
Suggested Limits
11.6.21
The consent for the existing Damhead Creek CCGT Power Station in September
1996 contained two conditions related to noise from the operation of the plant Condition 26 ‘Operational Noise’, and Condition 29 ‘Noise Insulation’. Although these
conditions are only applicable to the existing Damhead Creek CCGT Power Station,
they are relevant when considering what may be acceptable for Damhead Creek 2.
A letter, dated 2nd November 1999 provided a submission for the discharge of
Condition 26. Section 11.4 of this submission outlined the operational noise criterion,
based on baseline noise measurements at the nearest NSRs. These are reproduced
in Table 11.7, with a comparison to the predicted level contribution for Damhead
Creek 2.
TABLE 11.7: EXISTING LIMITS
Location
Existing Damhead Creek
CCGT Power Station
Criterion Level,
LAeq, dB
Damhead Creek 2
Prediction, LAeq, dB
Junction Eshcol Rd./Jacob’s Lane
37
27
Jacob’s Lane, Market Garden
37
29
11.6.22
It is therefore predicted that the noise contribution from the existing Damhead Creek
Power Station and Damhead Creek 2 will fall within the original operational planning
noise criterion for the existing Damhead Creek CCGT Power Station. Therefore it is
recommended that the existing planning noise criterion for existing Damhead Creek
CCGT Power Station is extended to relate to both plants.
11.7
Mitigation
Construction
11.7.1
In order to keep noise impacts from the construction phase to a minimum, all
construction activities would be carried out in accordance with the recommendations
of BS 5228. In addition, the following mitigation measures would be implemented
through the Construction Environmental Management Plan (CEMP):
11.7.2
Core site working hours would be agreed with the Local Authority, and are specific to
the construction site. These are generally Monday to Saturday 07:00 to 19:00 hours.
It would be necessary to work outside these core hours for certain activities but this
would be with the prior agreement of the local authority.
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NOISE AND VIBRATION
11.7.3
Specific method statements and risk assessments would be required for night
working. In order to minimize the likelihood of noise complaints in such eventualities,
the contractor would inform and agree the works in advance with the Environmental
Health Officer, informing affected residents of the works to be carried out outside
normal hours. Furthermore, the residents would be provided with a point of contact
for any queries or complaints.
11.7.4
All vehicles and mechanical plant used for construction would be fitted with effective
exhaust silencers, and regularly maintained.
11.7.5
Inherently quiet plant would be used where appropriate. All major compressors would
be sound-reduced models fitted with properly lined and sealed acoustic covers which
would be kept closed whenever the machines are in use, and all ancillary pneumatic
percussive tools would be fitted with mufflers or silencers of the type recommended
by the manufacturers.
11.7.6
All ancillary plant such as generators, compressors and pumps would be positioned
so as to cause minimum noise disturbance. If necessary, temporary acoustic barriers
or enclosures would be provided.
11.7.7
ScottishPower will require its appointed contractor to minimize the impact of
construction activities through successful implementation of an agreed Construction
Environmental Management Plan (CEMP) and proper communication with local
residents.
Operation
11.7.8
While planning noise limits will be agreed with the local authority at the planning
consent stage, plant operators should aim to better these limits and reduce noise
emissions as far as possible. The following measures would serve to continually
monitor and minimize the impact of noise from Damhead Creek 2:
A computer model of the proposed plant items should be produced at the
detailed design stage, to calculate the predicted noise levels at the NSR
locations, and ensure that planning limits are adhered to. Detailed design will
ensure that site noise is mitigated as far as possible, through site layout and
orientation of noisy plant items.
Since tonal or impulsive noises are considered more annoying than continuous
noise sources, plant items should be silenced or otherwise controlled through
regular maintenance to ensure no such emissions are audible at NSR locations.
A programme of continual noise monitoring, including a noise survey shortly
following the commissioning of the new plant, shall be agreed with the Local
Authority and implemented at regular intervals. The aim of these surveys shall
be to ensure that plant noise levels as measured at the agreed NSR locations do
not exceed the planning noise limits agreed with the local authority. Noise
monitoring shall be undertaken in accordance with BS 4142.
In the event of a complaint by a local resident relating to noise levels during the
operation of the Development, an investigation shall be carried out by the
operator, or a representative thereof, to determine the likely cause of the
complaint, and any available remedial measures. Where it is deemed necessary
by the Local Authority, a written report detailing these measures and their
effectiveness will be provided.
Inherently quiet plant items will be selected wherever practicable. In addition to
the noise control measures mentioned above high performance silencers should
be fitted to achieve maximum noise attenuation on plant including gas turbine
and HRSG inlets and ductwork. Acoustic lagging and low noise trims will be
fitted to all pipe-work and noise generating steam valves.
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NOISE AND VIBRATION
High performance acoustic enclosures should be considered for all plant items
where practicable, not overlooking smaller plant items such as compressors and
pumps.
Internal surfaces within the turbine hall should be treated to control internal
reverberant noise levels. An appropriate treatment would consist of dense
mineral wool panel behind perforated sheet steel, or a spray on cellulose fibre
treatment.
In the interest of maintaining neighbourly relations and residential amenity, the
company will give a reasonable period of notice to residents prior to any nonnormal operations that would lead to an increase in noise levels. These should
be carried out between 0900 and 1700 hours during the weekdays, wherever
possible.
When non-normal and emergency operations lead to noise levels in excess of
the agreed planning limits, the operator will inform the local authority and
residents of the reasons for these operations, and the anticipated emergency
period.
11.8
Construction
11.8.1
Section 11.6 presented predictions and estimates of noise from ‘typical’ construction
plant which is likely to be used for the construction of the proposed Development.
These were assessed against the background levels, and no significant impacts from
construction noise were predicted. However, the mitigation detailed in Section 11.7 is
aimed to ensure that any noise produced during construction does not exceed these
predictions.
Operation
11.8.2
The calculation and assessment of operational noise in Section 11.6 is based on a
number of assumptions about the forms of mitigation, which the proposed
Development will incorporate. These forms of mitigation are detailed in Section 11.7.
11.9
11.9.1
In addition to the proposed development of Damhead Creek 2, the construction
Kingsnorth Units 5 and 6 on a site to the south has been proposed by E.ON. It is
anticipated that Kingsnorth Units 5 and 6 could be operational in 2018.
11.9.2
Noise prediction work was undertaken to support the ES for Kingsnorth Units 5 and 6,
and noise levels were predicted at a number of receptors that this assessment has
also considered. These noise levels are presented in Table 11.8.
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NOISE AND VIBRATION
TABLE 11.8: COMPARISON WITH PREDICTED NOISE FROM KINGSNORTH
UNITS 5 & 6
Location
NSR Description
Predicted
Rating Noise
Level due to
Damhead Creek
2
Rating Noise
Level from
Kingsnorth
Units 5 & 6 ES
dB(A)
Difference
Combined
Level
dB(A)
3
Riverview Cottage
25.6
34.7
9.1
35.2
5
Tunbridge Hill
25.5
35.4
9.9
35.8
6
Beluncle Farm
26.9
35.2
8.3
35.8
8
Eschol Lane / Jacobs Lane
26.9
36.6
9.7
37.0
10
Market Garden / Dog
Kennels
29.0
39.1
10.1
39.5
11.9.3
As the above table demonstrates, noise levels from the Damhead Creek 2 project are
predicted to be between 8 and 10 dB below those predicted for Kingsnorth Units 5
and 6 at local NSRs.
11.9.4
This means that should the Kingsnorth 5 and 6 project become operational before
Damhead Creek 2, the addition of Damhead Creek 2 would not be likely to be
perceptible at local NSRs due to the prior increase in ambient noise from Kingsnorth 5
and 6.
11.9.5
If Damhead Creek 2 were to become operational before Kingsnorth 5 and 6, then the
noise impact upon operation of Damhead Creek 2 would be as described above.
With the subsequent addition of Kingsnorth 5 and 6, any prior perception of noise
from Damhead Creek 2 would cease, as it would be masked by noise from Kingsnorth
5 and 6.
11.9.6
As the ‘combined’ column shows, the noise levels from a combination of Damhead
Creek 2 and Kingsnorth Units 5 & 6 are within 0.5 dB of the noise levels with
Kingsnorth Units 5 and 6 operating alone. This difference is not significant, therefore
the impact of the combined projects will essentially be as predicted for the Kingsnorth
Units 5 and 6. The Kingsnorth 5 and 6 ES notes that the new Kingsnorth 5 and 6
plant will be less noisy than the existing plant and so it can be surmised that there
may even be an overall noise reduction in the area surrounding the two
Developments.
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12
12.1
Summary
12.1.1
The substantial buildings envisaged on the Damhead Creek 2 site are the turbine hall,
HRSGs, air cooled condenser and storage tanks. The remaining plant and equipment
will, predominately be housed in relatively low buildings, of the order of 3 to 6 m in
height. The tallest structures on site will be the 75 m high stacks that will be similar in
appearance to the existing 75 m high stacks at the existing Damhead Creek CCGT
Power Station.
12.1.2
Photomontages have been prepared based on the likely design concept for Damhead
Creek 2 from which an impression can be ascertained as to the likely scale and visual
impact of the Development both with and without the inclusion of the proposed
Kingsnorth Units 5 and 6. These photomontages are described below, and are
included in Volume 3. The predicted views from eight viewpoints have been identified
as being representative of the likely visual impact that would be encountered in the
area.
12.1.3
These photomontages have formed the basis of a landscape and visual impact
assessment undertaken as part of the EIA. The study found that the project would
not have unacceptable impacts to the local landscape, which is already dominated by
the existing Kingsnorth Power Station and other industrial plants including the existing
Damhead Creek CCGT Power Station and the existing Kingsnorth Industrial Estate.
12.1.4
Damhead Creek 2 will be designed so as to be similar in appearance to the existing
Damhead Creek CCGT Power Station and will seek to employ the same finish.
12.2
Introduction
12.2.1
This Section presents the landscape and visual impact assessment for Damhead
Creek 2. The assessment describes the following:
The assessment methodology and significance criteria adopted in undertaking
the assessment;
The baseline conditions against which Damhead Creek 2's impact is assessed;
The potential (pre-mitigation) significant environmental impacts which Damhead
Creek 2 may have on the area;
The mitigation measures to be adopted; and
Resultant residual (post-mitigation) significant environmental impacts of the
construction and operational phases of Damhead Creek 2.
12.2.2
The Section considers direct and indirect impacts of the development of Damhead
Creek 2 together with cumulative impacts in relation to other developments and plant
in the local area, i.e. the existing and proposed plant at Kingsnorth Power Station
(Kingsnorth Units 5 and 6) and the proposed Kingsnorth Business Park (Goodman
Developments Limited).
12.2.3
The assessment considers the existing baseline and the construction and operational
phases in relation to Damhead Creek 2.
12.3
12.3.1
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NRM8
Coastal Management
C4
Landscape and Countryside Management
KTG7
Green Initiatives
EN1
Protecting Kent’s Countryside
EN2
Protecting Kent’s Coast and Estuaries
EN3
Protecting and Enhancing Countryside Character
EN5
Special Landscape Areas
EN9
Trees, Woodland and Hedgerows
EN12
River Corridors
QL1
Quality of Development and Design
S4
Landscape and Urban Design Guidance
BNE1
General Principles for Built Environment
BNE5
Lighting
BNE6
Landscape Design
BNE22
Environmental Enhancement
BNE33
Special Landscape Areas
BNE34
Areas of Local Landscape Importance
BNE45
Undeveloped Coast
BNE46
Developed Coast
CF10
Overhead Supply Lines
Designations
12.3.2
The Damhead Creek 2 site is situated on the southern edge of the Hoo Peninsula, a
tongue of land between the Thames and Medway estuaries. Although the Damhead
Creek 2 site is not covered by any environmental designations, the surrounding
mudflats and saltmarsh are highly significant landscapes, and are protected by local,
national and international designations. These designations are shown in Figure
12.1.
Site of Special Scientific Interest (SSSI)
12.3.3
The Medway Estuary and Marshes are notified as a SSSI. Covering an extensive
area in excess of 4700 ha, the SSSI comprises a mosaic landscape of mudflats,
saltmarsh, grazing marsh, dykes and fleets, and smaller areas of scrub, reedbeds,
sand dunes and shell sand beaches. The habitats support internationally significant
populations of wildfowl, invertebrates and ‘an outstanding assemblage of plant
species” (English Nature citation, 1992). The SSSI designated habitats surrounding
the Damhead Creek 2 site are also BAP Priority Habitats (Coastal and floodplain
grazing marsh, and mudflats).
RAMSAR Site and Special Protection Area (SPA)
12.3.4
Parts of the SSSI are also designated as Special Protection Areas and Ramsar Sites.
This is mainly due to the populations of important bird species that either inhabit the
designated site during the breeding seasons, over winter, or stop off during migratory
passage.
Special Landscape Area (SLA)
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12.3.5
The North Kent Marshes are notified as a Special Landscape Area by Kent County
Council for the following reasons:
“The North Kent Marshes have a special and unusual character which is rare in a
country, if not in a national context. Their wild and remote character is accentuated
by the contrast with the busy Thames estuary, extensive areas of urban development
nearby, and an industrial backdrop to the horizon. The area itself is largely
underdeveloped and the marshes are of international wildlife interest”.
12.3.6
The SSSI, RAMSAR, SPA and SLA are included in the Environmentally Sensitive
Areas in Figure 12.1.
Areas of Local Landscape Importance (ALLI)
12.3.7
A number of areas in the local vicinity are designated as Areas of Local Landscape
Importance in the Medway Local Plan. This is a local landscape designation which
reflects significance in enhancing local environmental, amenity and aesthetic
landscape qualities. ALLIs in the local area include Deangate Ridge, Chattenden
Ridge woodlands, Cockham Farm Ridge, and the rural landscape of Gillingham
riverside.
12.3.8
Policy BNE34 of the Medway Local Plan sets out criteria to minimise the impact of
development within ALLIs with respect to landscape character.
Scheduled Monuments
12.3.9
Darnet Fort and Hoo Fort Scheduled Ancient Monuments are both located within a
few kilometres south of the Damhead Creek 2 site.
Listed Buildings
12.3.10
There are three Grade II listed buildings in 2 km of the site including:
Cold Arbour Farm, a timber-framed and clad in brick farm house just over 1km to
the north of the Development site;
Lancers Farm House, a 17th Centaury timber-framed house about 1km to the
west of the Development site; and
White Hall House a 16th Century house altered in early 19th Century just over
1km to the north of the Development site.
12.3.11
Further details of these properties are included in Appendix J.
Landscape Character
12.3.12
Landscape character is what makes an area unique. Natural England define it as "a
distinct, recognisable and consistent pattern of elements, be it natural (soil, landform)
and/or human (for example settlement and development) in the landscape that makes
one landscape different from another, rather than better or worse". By understanding
how places differ Natural England can ensure that future development in an area is
well situated, sensitive to its location, and contributes to environmental, social and
economic objectives for the area.
12.4
National Context
12.4.1
The Damhead Creek 2 site is located within the Greater Thames Estuary character
area (as identified by Natural England’s Joint Character Areas) and is close to the
North Kent Plain Character Area.
12.4.2
Key characteristics of the Greater Thames Estuary Joint Character Area include:
“Extensive open spaces dominated by the sky within a predominantly flat, lowlying landscape. The pervasive presence of water and numerous coastal
estuaries extend the maritime influence far inland.
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Pressure on edges, particularly around major estuaries, from urban, industrial
and recreational developments together with the associated infrastructure
requirements often on highly visible sites against which the marshes are often
viewed.
The Thames edge marshes are themselves subject to the chaotic activity of
various major developments including ports, waste disposal, marine dredging,
urbanisation, mineral extraction and prominent power stations plus numerous
other industry-related activities such as petrochemical complexes.”
12.4.3
Key characteristics of the North Kent Plain Joint Character Area include:
“An open, low and gently undulating landscape characterized by high-quality,
fertile, loamy soils dominated by agricultural land uses.
The exposed arable/horticultural fields have a sparse hedgerow pattern and only
limited shelter belt planting around settlements and farmsteads. Gently
undulating, the large intensively cropped fields to the west are mainly devoid of
trees and hedges.
Urbanisation and large settlements are often visually dominant in the landscape
due to the lack of any screening woodlands or shelterbelts.
Lines of pylons dominate the open and often treeless landscape.”
12.4.4
National Landscape Character Areas are shown in Figure 12.2.
12.5
Local Context
Landscape Assessment of Kent
12.5.1
The Landscape Assessment of Kent was prepared in 2004. The Damhead Creek 2
site falls within the Medway Marshes Local Landscape Character Area (LLCA). Land
immediately to the north of the Damhead Creek 2 site lies within the Hoo Peninsula
LLCA.
12.5.2
Key characteristics of the Medway Marshes LLCA as described in the Landscape
Assessment of Kent include:
“Low lying and flat with huge open skies and extensive views. To the north of the
river, the marshes are dominated by the massive industrial complexes of Grain
and Kingsnorth which sit in grand isolation amidst open marshland.
The landscape of the Medway marshes has long been associated with industrial
use.”
12.5.3
Key characteristics of the Hoo Peninsula LLCA as described in the Landscape
Assessment of Kent include:
“Prominent hills and low-lying alluvial marshes.
Flat/undulating farmland. Decline in orchards and mixed farmland with
shelterbelts.
Intensive, open farmed arable land.
Intrusive influence of industrial development”.
12.5.4
Local Landscape Character Areas are shown in Figure 12.3.
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12.6
12.6.1
The Assessment Methodology used is based on revised guidance set out in
‘Landscape and Visual Impact Assessment’ published by the Landscape Institute and
Institute for Environmental Assessment (2002).
12.6.2
The first stage of the assessment involves establishing the landscape and visual
baseline of the proposed development site and the surrounding area, through desktop
studies and field surveys. Sensitive landscape and visual receptors are then
identified i.e., those landscape elements and features and visual receptors that are
likely to be directly or indirectly affected by the proposed development.
12.6.3
The assessment of landscape combines the visual experience with an evaluation of
landscape character, through features and attributes described in terms of:
Pattern: the relationship between topography, elevation, the degree of visual
enclosure and the physical scale of landscape features
Tranquillity: remoteness and sense of isolation
Cultural and historical associations/features and their settings
Land cover, land use, ecology and management.
12.6.4
Having drawn together the baseline information from the desktop studies and the field
surveys, this information has been used to describe the character of the Damhead
Creek 2 site itself and the local area.
12.6.5
The final stage of the baseline study involved the evaluation of the condition, quality
and value of the landscape and existing views over the Damhead Creek 2 site, in
order to assess the sensitivity of landscape and visual receptors to change.
12.6.6
The second stage of the assessment process initially involves the identification of
landscape and visual impacts associated with Damhead Creek 2. Landscape and
visual impacts or effects can be direct, indirect, cumulative, positive or negative and
permanent or temporary. The identification of impacts clearly distinguishes between
those impacts upon the physical landscape resource and those associated with visual
amenity and views across the Damhead Creek 2 site. Impacts are also considered in
terms of their duration i.e., whether they are permanent (i.e., operational) or
temporary (i.e., normally associated with the construction phase).
12.6.7
Having identified all visual impacts, their scale or magnitude is then assessed using
four levels or categories ranging from high, through moderate to low or no impact
where no change is anticipated, as described in Table 12.1. In assessing the
magnitude of any landscape impact due regard is given to the scale, nature and
duration of the impact. For example, a subtle change in the pattern of the landscape
confined to a limited area for only a short period is likely to be considered low in
magnitude.
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TABLE 12.1: VISUAL IMPACT MAGNITUDE EVALUATION CRITERIA
Category
Evaluation criteria
High
The scale of the change in the view is large with respect to the loss or change to features
in view.
The nature of the impacts is generally permanent.
The number of affected views or visual receptors is high.
The full extent of the view would be occupied by the Development.
The introduction of new elements is considered to be in total contrast to the character of
the existing landscape.
Moderate
The scale of the change in view is moderate with respect to the loss or change to features
in view.
The nature of the impacts is either permanent or temporary.
A partial extent of the view would be occupied by the Development.
The introduction of new elements is considered not to be substantially in contrast to the
character of the existing landscape.
Affected viewers are transient i.e. from footpaths
Low
The scale of the change in view is low with respect to the loss or change to features in
view.
The nature of the impacts is either permanent or temporary.
The number of affected views or visual receptors is low.
A small or limited extent of the view would be occupied by the Development
The introduction of new elements may not be considered to be unduly in contrast to the
existing landscape characteristics.
Affected viewers are transient i.e. from a moving vehicle.
No change
12.6.8
Where no part of the proposed Development is discernible.
In order to inform the decision making process, an impact assessment should report
on those environmental effects that are considered to be significant. The two
principal criteria determining significance are the sensitivity of the receptor and the
magnitude of the impact or effect. In order to predict the significance of the landscape
and visual impacts of Damhead Creek 2, this assessment therefore combines the
sensitivity to change of the various receptors within the Damhead Creek 2 site with
the assessment of the magnitude of the impact in question. .
12.6.9
In order to evaluate the relative significance of either landscape or visual impacts a 3point impact scale ranging from slight through moderate to large has been adopted.
These significance thresholds are determined from the differing combinations of
levels of sensitivity and magnitude as shown in Table 12.2.
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MAGNITUDE
TABLE 12.2: DETERMINANTS OF SIGNIFICANCE
High
moderate
large / moderate
Large
Moderate
slight / moderate
moderate
large / moderate
Low
slight
slight / moderate
Moderate
Low
Moderate
High
SENSITIVITY
12.6.10
The significance of the identified landscape impacts is based on the criteria shown in
Table 12.3.
TABLE 12.3: CRITERIA FOR SIGNIFICANCE OF LANDSCAPE IMPACTS
Significance
Effects / Definition
Large Beneficial
(Positive) Effect
Proposal integrates highly successfully with local landscape character and provides
significant enhancements to local landscape character and scenic quality
Moderate Beneficial
(Positive) Effect
Proposal fits well within local landscape character and provides enhancements to
local landscape character and scenic quality
Slight Beneficial
(Positive) Effect
Proposal fits with local landscape character and provides limited enhancements to
local landscape character and scenic quality
Neutral Effect
Proposals are in keeping with local landscape character and would not result in
significant negative or positive effects
Slight Adverse
(Negative) Effect
Proposals do not quite fit with local landscape character and would result in minor
negative impacts which cannot be fully mitigated, within an area of non designated
landscape quality
Moderate Adverse
(Negative) Effect
Proposals are out of scale or otherwise at odds with local landscape character,
cannot be fully mitigated and would impact on an area of locally designated
landscape quality
Large Adverse
(Negative) Effect
Proposals are at considerable variance with local landscape character, cannot be
adequately mitigated and would impact on an area of nationally designated
landscape quality
12.6.11
Impacts can, therefore, be beneficial (positive) or adverse (negative) as well as
neutral where there is either no impact or where beneficial or adverse impacts
balance. For the purpose of this assessment, impacts that have been assessed as
being either moderately adverse or beneficial or above are considered to be
significant in terms of the Electricity Works (Environmental Impact Assessment)
(England and Wales) Regulations 2000. Although slight adverse or beneficial and
neutral impacts are not considered significant, they remain worthy of consideration
throughout the decision making process.
12.6.12
Having assessed the significance of all landscape and visual impacts associated with
Damhead Creek 2, additional mitigation measures over and above those incorporated
within the current proposed layout of Damhead Creek 2 are identified. The purpose
of these mitigation measures is to avoid, reduce and where possible remedy any
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significantly adverse impacts. The residual impacts after taking into account any
proposed mitigation measures are then stated in the final stages of the impact
assessment process.
12.6.13
In the final sections of the assessment the cumulative impact of Damhead Creek 2 in
the context of other proposed developments in the local area is assessed.
12.7
Landscape Character
12.7.1
The Damhead Creek 2 site is located on the southern edge of the Hoo Peninsula
overlooking the Medway Estuary. The existing Damhead Creek CCGT Power Station
site is located to the north of the existing Kingsnorth coal fired power station. The
majority of Damhead Creek 2 buildings would be located on a triangle of land
immediately to the east of the existing Damhead Creek CCGT Power Station. Only
the substation would be located without this land and potentially in the future the
carbon capture equipment (see Figure 5.1).
12.7.2
The proposed location for the Damhead Creek 2 site currently comprises areas of
unmanaged grassland and scrub and hardstanding. The site is underlain by London
Clay covered by superficial alluvium deposits. The land is thought to have been
drained in the late 19th century for agriculture. The only other use of the land has
been as a naval airship installation between 1912 and 1920.
12.7.3
The land within and immediately surrounding the Damhead Creek 2 site is fairly flat
and low lying at approximately 5 m Above Ordnance Datum (AOD). To the north and
west the land rises gently to around 40 m AOD on the Hoo Peninsula.
12.7.4
The landscape of the Medway Marshes to the south and east of the Damhead
Creek 2 site is typical of the Medway Estuary. The land is flat with a mix of narrow
creeks, saltings, mudflats and small islands. Damhead Creek is the main nearby inlet
which drains into the Medway Estuary. The high tide mark is defined by the raised
bund of the sea wall. The larger conurbations of Chatham and Gillingham are located
on the southern side of the Medway Estuary.
12.7.5
The land immediately north, west and south of the Damhead Creek 2 site is industrial
in use and character. Land to the west comprises the existing Damhead Creek
CCGT Power Station. To the south there is a narrow strip of undeveloped land, which
separates Damhead Creek from the existing Kingsnorth Power Station. The existing
Kingsnorth Industrial Estate is located to the north and east.
12.7.6
Within these industrial areas there are belts of tree and shrub planting, the more
substantial and mature areas are associated with Kingsnorth Power Station. A belt of
hybrid poplars follows the southern boundary of the Kingsnorth Industrial Estate and
there are a number of young tree and shrub belts associated with the existing
Damhead Creek CCGT Power Station site.
12.7.7
Kingsnorth Power Station is by far the largest existing development in the locality in
terms of land take, the scale of the main buildings and plant and the height of the
stack at 198 m.
12.7.8
To the north and west the land rises gently to the undulating agricultural landscape of
the Hoo Peninsula. The majority of the land is under mixed arable and vegetable
production. Fields are, in the main, large in size and bordered by a combination of
fragmented hedges, ditches and shallow bunds. There is limited woodland cover,
although hedge lines (including some domestic conifer hedges) and occasional
hedgerow trees do break up the open character of the landscape. The landscape is
traversed by pylons emanating from the electricity sub station at the Kingsnorth
Power Station site. There is a network of narrow country lanes and a number of
public rights of way (mostly footpaths) including sections of the Saxon Shorne Way.
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12.7.9
The main settlements in the immediate locality are Hoo St Werburgh to the west and
Stoke to the north east. Hoo St Werburgh is by far the largest local settlement and
comprises a small, old centre surrounded by extensive post war residential
development. There are also areas of linear development on the A228 around
Sharnall Street and Fenn Street and a number of smaller groups of properties around
Tunbridge Hill and North Street. There is no strong settlement pattern or architectural
style, which would characterise these local towns and villages.
Potential Visual Receptors
12.7.10
The predicted Zone of Visual Influence (ZVI) associated with Damhead Creek 2 is
shown on Figure 12.4. This plan is based on a desk top assessment and does not
take into account the effects of built development and vegetation. This ZVI has been
assessed in the field in order to refine the anticipated ZVI associated with Damhead
Creek 2, to identify sensitive landscape and visual receptors and to assess the overall
character, quality and condition of the local landscape.
Views from the North
12.7.11
The land rises gently to the north towards a broad ridge which runs from St Mary Hoo,
south eastwards to High Halstow and rising still further towards Lodge Hill. The
landscape is typically open and undulating comprising agricultural land with
occasional small settlements (Tunbridge Hill and North Street) and individual farms
and properties. There is a network of narrow country lanes and public rights of way.
Expansive views can be gained from many locations towards the Medway Estuary to
the south and east. Kingsnorth Power Station and the existing Damhead Creek
CCGT Power Station are dominant features in these views.
12.7.12
The A228 runs just below the crest of the ridge between Chattenden and Lower
Stoke. Vehicle travellers on the A228 gain middle distance views over the rolling
farmland towards the Damhead Creek 2 site. In addition there are a number of small,
mainly linear settlements on the A228 (Sharnal Street and Fenn Street) and other
individual properties, which benefit from similar views.
Views from the West
12.7.13
Hoo St Werburgh, the largest settlement in the immediate vicinity of the Damhead
Creek 2 site is located just over 3 km to the west. The older centre of the town is
located on the edge of the Medway marshes. Built development has more recently
expanded to the higher land to the north and west of the town. Properties on the
eastern edges of the town benefit from views to the south and east towards the
12.7.14
The intervening flat areas of arable farmland and grazing marsh are traversed by a
network of public rights of way, which includes the Saxon Shorne Way Long Distance
Footpath. There are a number of clumps of riparian woodland and scrub, which serve
to break up views towards The Damhead Creek 2 site.
12.7.15
South west of Hoo St Werburgh the land rises in the form of a shallow ridge towards
Beacon Hill and Broad Street. The Saxon Shorne Way follows the crest of the ridge,
with views south and east over the Medway estuary and towards the Damhead Creek
2 site.
Views from the South
12.7.16
There are expansive open views northwards over the Medway Estuary towards
Kingsnorth and the Damhead Creek 2 site from the estuary itself and areas on the
southern side of the Medway. To the south west much of the land bordering the
estuary is residential and industrial in character and includes the new residential
development on St Mary’s Island, the Strand riverside park Leisure Centre and other
development on the northern edges of Chatham and Gillingham along the A289.
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12.7.17
East of Gillingham the land is more rural in character, but includes popular recreation
destinations such as Riverside Country Park. The Saxon Shorne Way follows the
estuary edge through much of this area. There are expansive views over the Medway
towards the Hoo Peninsula and the Isle of Grain.
Views from the East
12.7.18
Land to the east is predominantly flat and extends to the nearby industrial
developments on the Isle of Grain. The intervening land combines estuary and
grazing marsh. Long and middle distance views can be gained over this flat
landscape, in particular from the footpath which follows the crest of the flood defence
bund.
12.7.19
Stoke, Middle Stoke and Lower Stoke are all small settlements located on the slightly
higher ground to the north east. Stoke is the closest of the three settlements and
properties on the southern and western edges of the village benefit from expansive
views over the Medway to the south west.
Illustrative Viewpoints
12.7.20
For the purpose of this assessment eight viewpoints have been selected in order to
illustrate the typical visual impact of Damhead Creek 2 when viewed from the
surrounding area. The location of these viewpoints is shown in Figure 12.5. A
number of these viewpoints replicated those used in the Environmental Assessment
for the proposed replacement to Kingsnorth Power Station (Kingsnorth Units 5 and 6)
and the proposed Kingsnorth Business Park by Goodman Developments Limited.
Two have been replaced with new viewpoints which it was felt by the council and PB
provided a more representative illustration of the impact of Damhead Creek 2. The
viewpoints are described below.
12.7.21
Two sets of photomontages have been prepared, based on two different outcome
scenarios. Figures 12.6 to 12.13 indicate the existing view and the anticipated view
incorporating Damhead Creek 2, whereas Figures 12.14 to 12. 21 indicate the
existing view and the anticipated view incorporating both Damhead Creek 2 and the
proposed Kingsnorth Units 5 and 6. Figures 12.14 to 12.21 are more representative
of the cumulative effects of all the proposed developments in the area.
TABLE 12.4: ILLUSTRATIVE VIEWPOINTS
No.
Location
1
St. Mary’s Island,
viewing point from
Finsborough Down
Approximate
Distance from
Site
4 km
Comments
This viewpoint is characteristic of views from
St Mary’s Island and other residential areas
bordering the A289 further east.
Sensitivity
Moderate
A number of properties and the public right of
way at Finsborough Down benefits from open
views over the estuary.
2
View from causeway
at Horrid Island in
Riverside Country
Park.
4 km
The Saxon Shorne way follows the southern
edge of the Medway Estuary, east of
Gillingham. Riverside Country Park is a
popular local destination and many visitors
walk to Horrid Island to enjoy views over the
estuary.
Moderate
3
Raspberry Hill,
looking across
Bedlam’s Bottom.
9 km
This viewpoint is characteristic of views over
the estuary from visual receptors further east
and shows the Damhead Creek 2 site in
context with other industrial development on
the Isle of Grain.
Moderate/Low
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No.
Location
4
View from the
junction between
Vicarage Lane and
Abbots Court Road
on the southern edge
of Hoo St Werburgh.
3 km
Junction between
A228 (Fenn Street)
and Ratcliffe
Highway at Fenn
Street, east of High
Halstow.
3 km
Footpath RS33 (on
flood defences)
adjacent to A228,
just south of Stoke
Marshes.
4.5 km
Stoke Road at the
junction with Creek
Lane on the southern
edge of Stoke
Village.
2.5 km
Tunbridge Hill on
Stoke Road.
1.5 km
5
6
7
8
Approximate
Distance from
Site
Comments
Sensitivity
Hoo St Werburgh is the largest settlement in
the immediate locality.
High
This view is characteristic of views from
residential properties, public highways and
rights of way to the west of the Damhead
Creek 2 site.
The A228 runs close to the crest of the ridge
between Chattenden and Lower Stoke.
There are a number of small linear
settlements on the route.
Moderate
Views towards the Damhead Creek 2 site
are, in the main, over farmland.
Footpath RS33 follows the top of the bund to
the flood defences on the north side of the
estuary.
Moderate
The view is characteristic of more distant
views from visual receptors to the east, on
the approaches to the Isle of Grain.
This view is characteristic of near to middle
distance views from receptors on higher
ground to the north east of the Damhead
Creek 2 site.
High
There are a number of properties on the
southern edge of Stoke which benefit from
open views over farmland to the south and
west.
Tunbridge Hill is the closest group of
properties to the Damhead Creek 2 site.
High
Similar views are gained from the groups of
properties at North Street and around
Beluncle Farm. The view is characteristic of
the outlook from Stoke Road and other visual
receptors, including public rights of way
around Tunbridge Hill.
12.8
Potential Impacts
Construction
12.8.1
The principal anticipated landscape and visual impacts associated with the
construction phases(s) are:
Landscape and visual impact associated with temporary site compounds,
including temporary lighting, fencing and temporary buildings and structures;
Storage of materials (lay down areas) and other plant and machinery;
Site clearance including land associated with the Damhead Creek 2 site and
other temporary site compounds; and
Temporary plant such as cranes and vehicle movements associated with
construction on the Damhead Creek 2 site.
Operation
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12.8.2
The structure and operation of Damhead Creek 2 are described in detail in Section 5
of this ES.
12.8.3
The Damhead Creek 2 site will result in the loss of approximately 6.2 ha of currently
undeveloped land, to the east of the existing Damhead Creek CCGT Power Station.
This land currently comprises a mix of rough grassland, scrub and hardstanding.
12.8.4
The proposed layout for Damhead Creek 2 is shown on Figure 5.1.
12.8.5
The main plant on the Damhead Creek 2 site will be comprised of two gas turbines,
with associated an associated HRSGs serving steam turbine equipment with an
output of around 1000 MWe. Based on the illustrative layout, one of the turbine units
is located on a north south axis, with a stack (the highest element of plant) located in
the north west corner of the site. The second unit is located on a west east axis with
the stack located in the south east corner of the site. This layout represents a likely
layout though the final layout will be the subject of detailed design studies by a future
contractor who will be selected during a competitive tendering process. The ultimate
design of the plant will be agreed with Medway Council before the start of the
construction phase.
12.8.6
The composition and size of the proposed plant is summarised below.
TABLE 12.5: DAMHEAD CREEK 2 PROPOSED PLANT DIMENSIONS (m)
Height (m)
Length (m)
Breadth (m)
HRSG Enclosure (2 No.)
40
30
30
Turbine Hall (2 No.)
28
80
30
Air Cooled Condensers (2 No.)
40
75
75
Height (m)
Diameter (m)
Deionised Water Tank
18
31
Raw Water Tank
18
27
Stack (2 No.)
75
5.9
12.8.7
The buildings and plant will be of a modern and functional design and will be industrial
in character and appearance. Damhead Creek 2 will relate closely to the existing
Damhead Creek CCGT Power Station in terms of scale, design, appearance and
colour. The structure will have a relatively simple clear outline, with the use of
cladding and materials with finishes in recessive colours, to match the existing
Damhead Creek CCGT Power Station.
12.8.8
The main impacts associated with the operation of Damhead Creek 2 will be:
Permanent daytime visual impacts associated with Damhead Creek 2 which will
introduce new, industrial plant to the locality;
Permanent night time visual impacts associated with lighting for Damhead Creek
2;
New perimeter fencing and internal access roads;
Change of land use from the current undeveloped use; and
Loss of existing landscape features associated with the Damhead Creek 2 site.
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12.9
Landscape Character
Landscape Pattern
12.9.1
Damhead Creek 2 will involve the permanent removal of all existing landscape
features on the Damhead Creek 2 site. The Damhead Creek 2 site currently
comprises a mix of rough grassland and hardstanding with occasional areas of scrub.
There are no locally significant landscape features such as hedgerows, trees, creeks,
wetland or grazing marsh, which are characteristic of the Hoo Peninsula or Medway
Marshes Landscape Character area.
12.9.2
The baseline conditions include the existing Damhead Creek CCGT Power Station,
Kingsnorth Power Station and Kingsnorth Industrial Estate. Whilst the design and
layout of Damhead Creek 2 would be out of keeping with the landscape pattern of the
surrounding rural areas it would be in keeping with the scale and layout of these
existing developments. The existing 198 m stacks and plant associated with the
existing Kingsnorth Power Station are of a considerably greater scale than Damhead
Creek 2’s stack at 75 m.
12.9.3
In this context the Damhead Creek 2 site would have a slight adverse impact on
landscape pattern.
Tranquillity: Remoteness and Sense of Isolation
12.9.4
Despite the existence of large scale industrial plant at Damhead Creek and
Kingsnorth and further east at the Isle of Grain, much of the Medway Estuary and Hoo
Peninsula Character Areas retain a strong sense of tranquillity and remoteness. The
Damhead Creek 2 site would extend the area under industrial development around
Kingsnorth, but would only marginally extend the area of such development. The
Damhead Creek 2 site would not introduce built development to new locations in the
local area. Noise impacts associated with Damhead Creek 2 would be largely
absorbed within impacts associated with the existing developments as is discussed in
the Noise section of this ES.
12.9.5
As such Damhead Creek 2 would only have a slight adverse impact on tranquillity,
remoteness and sense of isolation.
Cultural and Historical Associations / Features and their Settings
12.9.6
There are no features of heritage significance on the Damhead Creek 2 site itself.
Whilst the Damhead Creek 2 site would be visible from some historic sites and
features, notably Darnet and Hoo Forts on the Medway Estuary, Damhead Creek 2
would not impact on the setting of these features due to their distance from the
proposed Damhead Creek 2 Power Station.
12.9.7
There are 3 Grade II listed buildings within 2 km of the Development site however the
setting of these buildings will not be significantly impacted on by the project.
Land Cover, Land Use, Ecology and Management
12.9.8
The land cover and land use of the Damhead Creek 2 site would be permanently
changed from the existing area of rough, unmanaged grassland and hardstanding to
the proposed industrial use. The existing land does not form part of an existing
agricultural holding, is not accessible to the general public and is of limited ecological
and heritage value. As such the loss of this area would have a slight adverse impact
on land cover and land use.
12.9.9
The land is currently not managed to any specific objectives. Although it could be
argued that Damhead Creek 2 will bring the land under active management, it is
considered that Damhead Creek 2 would have a neutral impact on management.
June 2009
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SECTION 12
12.9.10
As such the impact on land cover, land use, ecology and management would be slight
adverse.
12.9.11
The overall impact of Damhead Creek 2 on local landscape character is, therefore
considered to be slight adverse.
Visual Impacts
12.9.12
The photomontages, shown in Figures 12.6 to 12.21, which are included in Volume 3,
provide illustrations of the anticipated visual impact of Damhead Creek 2 based on
two different outcome scenarios. Figures 12.6 to 12.21 indicate the existing view and
the anticipated view incorporating Damhead Creek 2, whereas Figures 12.14 to 12.21
indicate the existing view and the anticipated view incorporating both Damhead Creek
2 and the proposed Kingsnorth Units 5 and 6.
12.9.13
Damhead Creek 2 is similar in scale, design and layout to the existing Damhead
Creek CCGT Power Station. Damhead Creek 2 is to be sited adjacent to the existing
Damhead Creek CCGT Power Station and, as such, will visually appear as an
extension to the existing Damhead Creek CCGT Power Station.
12.9.14
The photomontages from Viewpoints 1 to 8, included as Figures 12.6 to 12.21 present
two different outcome scenarios. These are the:
Existing view, and the anticipated view incorporating Damhead Creek 2; and,
Existing view, and the anticipated view incorporating Damhead Creek 2 and the
proposed Kingsnorth Units 5 and 6.
12.9.15
Impacts associated with Damhead Creek 2 alone (Figures 12.6 to 12.13) are
discussed below. It should be noted in these figures that in the proposed view of
Damhead Creek 2, the existing Kingsnorth Units 1 to 4 are included. Although this
plant is due to be decommissioned before construction of Damhead Creek 2 begins,
there may be visual impacts which remain until the plant is demolished.
12.9.16
Cumulative impacts associated with Damhead Creek 2 and the proposed Kingsnorth
Units 5 and 6 (Figures 12.16 to 12.21) are discussed in Section 12.13.
12.9.17
A recessive colour scheme identical to that used on the existing Damhead Creek
CCGT Power Station is will be used. This is intended to break up the impact of the
built structures, which is shown on the photomontages.
12.9.18
Damhead Creek 2 will include the following lighting systems: site lighting and
emergency lighting, road lighting and area floodlighting. Lighting systems and design
Lighting systems will comply with current best practice and industry standards in order
to minimise light spread and glare off site.
Views from the North
12.9.19
The photomontages from Viewpoints 5 and 8 (Figures 12.10 and 12.13) provide
typical illustrations of the visual impact of Damhead Creek 2 from the land around the
A228 and Tunbridge Hill respectively.
12.9.20
Viewpoint 8 demonstrates the scale of the visual impact from near and middle
distance visual receptors on the gently rising land on the southern fringes of the Hoo
Peninsula. Open, expansive views over the Medway Estuary to the south are a
characteristic feature of the local area, where tree and hedge cover is limited. The
existing industrial developments at Kingsnorth and Damhead Creek are the dominant
features of these views. Damhead Creek 2 would increase the extent of this industrial
development. The proposed two new 75 m stacks would be the most prominent new
feature.
12.9.21
The magnitude of the change in the existing view is concluded as being moderate,
principally as Damhead Creek 2 will be largely viewed as an extension of the existing
June 2009
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Damhead Creek CCGT Power Station. Overall the anticipated visual impact of
Damhead Creek 2 in near and middle distance views is concluded as moderate
adverse, and therefore significant, as Damhead Creek 2 would add significantly to the
massing of buildings.
12.9.22
Further north, towards the A228 and the crest of the ridge to the Hoo Peninsula, much
of the shorter plant associated with both the existing Damhead Creek CCGT Power
Station and proposed Damhead Creek 2 is screened by intervening topography.
From Viewpoint 5, the proposed stack associated with Damhead Creek 2 would be
visible, but the shorter plant is largely screened. The lower plant is visible from visual
receptors further south and from some sections of the A228, principally in the western
sections between Hoo St Werburgh and Sharnal Street. Views from the A228 are
transient and the existing Kingsnorth Power Plant tends to be the dominant feature.
The magnitude of the change to the existing view is concluded as being low.
12.9.23
Damhead Creek 2 in these more distant views from the north is concluded as being
slight adverse, and therefore not significant based on the methodology outlined
above.
Views from the West
12.9.24
The photomontage from Viewpoint 4 (Figure 12.9) illustrates the typical impact of
Damhead Creek 2 from visual receptors on the western edge of Hoo St Werburgh.
Some elements of the shorter plant of both the existing Damhead Creek CCGT Power
Station and Damhead Creek 2 are partially screened in some views by areas of
intervening vegetation. The existing Kingsnorth Power Station is the dominant feature
in these views. Further north, from more elevated locations on Bell’s Lane, the views
are more open. The magnitude of the change to the existing view is concluded as
being low to moderate.
12.9.25
Overall the impact of Damhead Creek 2 in views from the less elevated locations to
the west is concluded as being slight adverse and, therefore not significant, as partial
screening is provided by vegetation and the existing Damhead Creek CCGT Power
Station in many locations.
Views from the South
12.9.26
Viewpoints1, 2 and 3 (Figures 12.6, 12.7 and 12.8 respectively) illustrate typical views
from key visual receptors on the south side of the Medway Estuary. In each of these
views the overall magnitude of the change in the view from Damhead Creek 2 is
considered to be low, as from all viewpoints Damhead Creek 2 is partially screened
by the existing Kingsnorth Power Station and the viewer is a considerable distance
from Damhead Creek 2.
12.9.27
From St Mary’s Island and Finsborough Down (Viewpoint 1) much of the existing
Damhead Creek CCGT Power Station and Damhead Creek 2 is screened by the
existing Kingsnorth Power Station. As such, the visual impact of Damhead Creek 2
is concluded as being neutral to slight adverse (where the proposed stack of
Damhead Creek 2 can be glimpsed) and, therefore not significant.
12.9.28
Similarly from visual receptors within and around Riverside Country Park including
Horrid Island (Viewpoint 2) and sections of the Saxon Shorne Way, much of the
shorter plant of Damhead Creek 2 is screened by the existing Kingsnorth Power
Station. Where visible the proposed Development would extend the massing of
buildings, but would not be discernible as a separate structure. Overall the impact of
Damhead Creek 2 from visual receptors in the vicinity of Riverside Country Park is
concluded as being neutral to slight adverse and, therefore, not significant .
12.9.29
Further west on the south side of the estuary the existing Damhead Creek CCGT
Power Station becomes less dominant. Damhead Creek 2 can barely be discerned
from the existing Kingsnorth Units 1 – 4 and the existing Damhead Creek CCGT
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Power Station in the Photomontage from Viewpoint 3, near Raspberry Hill. The
existing Isle of Grain Power stations are also visible, but not prominent in these views.
The visual impact of Damhead Creek 2 from Viewpoint 3, and other visual receptors
in the vicinity of Raspberry Hill is concluded as neutral.
Views from the East
12.9.30
The character of distant views from land in the vicinity of the Isle of Grain is illustrated
by the photomontage from Viewpoint 6 (Figure 12.11). Although distant, the existing
Kingsnorth and, to a lesser extent, the existing Damhead Creek CCGT Power Station
can be prominent in these views on clear days, forming dominant skyline features.
Damhead Creek 2 would add to the massing of the existing plant, which would remain
clearly distinguishable from Kingsnorth Power Station. The magnitude of the change
to the existing view is, however, considered to be low due to the distance between the
viewer and the Damhead Creek 2 site. The visual impact from receptors in the
vicinity of the Isle of Grain, including footpath RS33 and the A228, is concluded as
being slight adverse, and therefore not significant.
12.9.31
Viewpoint 7 (Figure 12.12) shows a typical view from the slightly elevated land to the
north east of the existing Damhead Creek CCGT Power Station and proposed
Damhead Creek 2, just to the south west of the village of Stoke. The taller and
shorter elements of plant are visible from these elevated viewpoints, although the
main buildings sit below the skyline, and there is little intervening vegetation to
provide mitigation. The overall magnitude of the change in view due Damhead Creek
2 is concluded as being low to moderate. Damhead Creek 2 would extend the mass
of industrial development at the heart of these near to middle distance views. The
visual impact of Damhead Creek 2 is concluded as being moderate adverse and,
therefore, significant based on the methodology adopted for the purposes of the
assessment.
12.10
Mitigation
Construction
12.10.1
A Construction Environment Management Plan (CEMP) would be prepared in support
of Damhead Creek 2. The CEMP will address the following:
Temporary storage of topsoil and any other material considered of value for
retention;
Temporary protection measures for vegetation and other features associated
with the site construction in accordance with current industry standards and
recognised best practice;
Design and layout of site construction areas including the location and type of
temporary security fencing and lighting;
Agreed site access routes and measures for the protection and, where
necessary, re-instatement of verges, vegetation and other landscape features on
routes used by construction traffic.
12.10.2
All areas affected by temporary site construction operations will be re-instated in
accordance with a restoration plan. The restoration plan would be agreed with
Medway Council as a condition of permission for the location of temporary site
construction areas. The restoration plan will address the following:
Method statements for the restoration of areas affected by construction to an
agreed after use and to an agreed timescale;
A Management Plan for reinstated areas to include any measures for the
vegetation establishment and planned long-term stewardship.
June 2009
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Operation
12.10.3
Damhead Creek CCGT Power Station and, as such, will appear as an extension to
the existing Damhead Creek CCGT Power Station.
12.10.4
A recessive colour scheme, identical to that used on the existing Damhead Creek
CCGT Power Station is to be used in order to break up the impact of the built
structures as shown on the photomontages.
12.10.5
to minimize light spread and glare off site.
12.10.6
There is existing landscape mitigation, principally on the northern perimeter of the
existing Damhead Creek CCGT Power Station. This mitigation combines shallow
mounding (up to 3 m in height) with areas of native planting. Whilst much of the
planting has established it has not achieved significant heights and has more the
character of areas of dense scrub. This mounding and planting would be effective in
screening low level plant and the security fencing in near views around the Damhead
Creek 2 site. The mounding is similar in scale and height to the flood protection bund
to the Medway estuary.
12.10.7
Landscape mitigation would be unlikely to achieve a significant reduction in the visual
impact of Damhead Creek 2. Extensive tree and shrub planting would also be out of
character with the local landscape of the Medway marshes.
12.10.8
Landscape planting can, however, be effective in reducing visual impact in near
views. It is, therefore, proposed to extend the mounding and planting associated with
the existing Damhead Creek CCGT Power Station to the northern edge of the
Damhead Creek 2 site. The extent of planting would take into account ecological
considerations and possible merging of planting with any landscape proposals
associated with the proposed Development by Goodman Developments Limited.
12.10.9
A landscape management plan would also be prepared for all landscaped areas and
other areas of semi natural landscape associated with the Damhead Creek 2 site, in
order to ensure the successful establishment of new planting, the re-instatement of
areas disturbed during construction and habitat management and enhancement.
12.11
Construction
12.11.1
All temporary site construction areas at the Damhead Creek 2 site will be re-instated
in accordance with the methodology described in 12.10.2.
12.11.2
As such the residual impacts associated with the temporary site construction area at
the Damhead Creek 2 site would be neutral.
Operation
12.11.3
Table 12.6 provides a summary residual impact assessment, described with
reference to the eight typical viewpoints referred to in Section 12.7. Table 12.6
describes the visual impacts associated with Damhead Creek 2 alone, therefore
concerning the photomontages in Figures 12.6 to 12.13.
June 2009
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SECTION 12
TABLE 12.6: VISUAL IMPACT ASSESSMENT FROM ILLUSTRATIVE VIEWPOINTS
No.
Location
Comments
1
St. Mary’s Island, viewing point
from Finsborough Down
This viewpoint is characteristic of views from St Mary’s Island and other
residential areas bordering the A289 further east.
Sensitivity of Visual
Receptor
Visual Impact
Assessment
High
Neutral to slight
adverse
High
Neutral to slight
adverse
Moderate
Neutral
Moderate
Slight adverse
Moderate
Slight adverse
A number of properties and the public right of way at Finsborough Down
benefits from open views over the estuary.
Damhead Creek 2 is largely screened by the existing Kingsnorth Power
Station. Stack and limited elements of lower plant visible from some visual
receptors
2
View from causeway at Horrid
Island in Riverside Country
Park.
The Saxon Shorne way follows the southern edge of the Medway Estuary, east
of Gillingham. Riverside Country Park is a popular local destination and many
visitors walk to Horrid Island to enjoy views over the estuary.
In distant views, much of lower plant screened by existing Kingsnorth Power
Station, although the stack is visible. Lower plant screened from the majority
of visual receptors.
3
Raspberry Hill, looking across
Bedlam’s Bottom.
This viewpoint is characteristic of views over the estuary from visual receptors
further east and shows the site in context with other industrial development on
the Isle of Grain.
Damhead Creek 2 is almost discernible from the existing Damhead Creek
CCGT Power Station.
4
5
View from the junction
between Vicarage Lane and
Abbots Court Road on the
southern edge of Hoo St
Werburgh.
Hoo St Werburgh is the largest settlement in the immediate locality. This view
is characteristic of views from residential properties, public highways and rights
of way to the west of the Damhead Creek 2 site.
Junction between A228 (Fenn
Street) and Ratcliffe Highway
at Fenn Street, east of High
Halstow.
The A228 runs close to the crest of the ridge between Chattenden and Lower
Stoke. There are a number of small linear settlements on the route. Views
towards the Damhead Creek 2 site are, in the main, over farmland.
June 2009
From lower viewpoints on the west side of Hoo St Werburgh the lower plant is
partially screened by intervening vegetation. From more elevated locations
Damhead Creek 2 is more prominent.
Lower plant is screened from the majority of locations on the A228. The bulk
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SECTION 12
No.
Location
Comments
Sensitivity of Visual
Receptor
Visual Impact
Assessment
Moderate
Slight adverse
Moderate
Moderate adverse
Moderate
Moderate adverse
of viewers are transient road users.
6
Footpath RS33 (on flood
defences) adjacent to A228,
just south of Stoke Marshes.
Footpath RS33 follows the top of the bund to the flood defences on the north
side of the estuary. The view is characteristic of more distant views from visual
receptors to the east, on the approaches to the Isle of Grain.
In distant views, the existing Damhead Creek CCGT Power Station and
Damhead Creek 2 do form prominent skyline features. Damhead Creek 2
would add to the massing of built structures on the skyline.
7
Stoke Road at the junction
with Creek Lane on the
southern edge of Stoke
Village.
This view is characteristic of near to middle distance views from receptors on
higher ground to the north east of the Damhead Creek 2 site. There are a
number of properties on the southern edge of Stoke which benefit from open
views over farmland to the south and west.
There is little intervening vegetation to provide even partial screening. Upper
and lower sections of plant would extend the scale and massing of buildings,
and would be visible as separate structures from some locations.
8
Tunbridge Hill on Stoke Road.
Tunbridge Hill is the closest group of properties to the Damhead Creek 2 site.
Similar views are gained from the groups of properties at North Street and
around Beluncle Farm. The view is characteristic of the outlook from Stoke
Road and other visual receptors, including public rights of way around
Tunbridge Hill.
The existing Kingsnorth Power Station is a dominant in these near views. The
proposed Kingsnorth Units 5 and 6 would add significantly to the massing of
the built structures.
June 2009
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SECTION 12
12.12
12.12.1
The assessment above considers the impacts associated with the construction of
Damhead Creek 2 in the context of the existing site conditions. At the time of the
consideration of this application two other applications, with associated EIAs are
under consideration by Medway Council, which would impact on the context for
Damhead Creek 2 development if granted consent. The content of these applications
are summarised below:
Kingsnorth Units 5 and 6
12.12.2
The proposal envisages the replacement of the existing four coal fired units (Units 1
to 4) with two more efficient and less polluting units (Units 5 and 6). The proposed
new units would be located on the strip of land between the existing Damhead Creek
CCGT Power Station and Damhead Creek 2 and the existing Kingsnorth Power
Station site. The existing Kingsnorth Units 1 – 4 would be removed. The principal
changes in the context of Damhead Creek would be the location of the new
Kingsnorth Units on adjacent land and the construction of two new units each with an
associated stack (the existing plant has just one stack).
12.12.3
The stacks would be of a similar scale in terms of height and area as the existing
198 m single stack.
Kingsnorth Business Park (Goodman Developments Limited)
12.12.4
Kingsnorth Business Park would be located on land to the north east of the proposed
location for Damhead Creek 2. The proposed development comprises a number of
warehouse buildings with associated landscape planting. A number of the proposed
units are of a significant area, but would be less than 20 m in height.
Damhead Creek 2 plus Kingsnorth Units 5 and 6
12.12.5
The photomontages from Viewpoints 1 to 8 (Figures 12.14 to 12.21) provide
illustrations of the cumulative visual impact of the Damhead Creek 2 plus the
proposed Kingsnorth Units 5 and 6.
12.12.6
The proposed Kingsnorth Units 5 and 6 would be located much closer to Damhead
Creek 2 than the proposed Kingsnorth Business Park. Visually, from the north and
the south, this would mean that the two developments and the existing Damhead
Creek CCGT Power Station would appear visually almost as a single development.
In views from the north and north east the impact of Damhead Creek 2 would also be
reduced as Damhead Creek 2 would always be viewed against the backdrop of
Kingsnorth Units 5 and 6. In views from the south the proposed Units 5 and 6 would
effectively screen much of Damhead Creek 2 development and as such Units 5 and 6
would reduce the impact of Damhead Creek 2 in views from the south.
This is
shown on the photomontages from Viewpoints 1, 2, 3, 5, and 8 shown in Figures
12.14, 12.15, 12.16, 12.18 and 12.21 respectively.
12.12.7
However, to visual receptors to the west and east there would be a clear visual
separation between the two developments. The cumulative impact of the two
developments would therefore be greater in these views as the developments would
appear largely as a single mass. This is shown on the photomontages from
Viewpoints 4, 6 and 7 shown in Figures 12.17, 12.19 and 12.20 respectively.
Damhead Creek 2 plus Kingsnorth Business Park
12.12.8
The proposed Kingsnorth Business Park would significantly increase the area of built
development in the locality. In views from the north and east the Kingsnorth Business
Park would extend the industrial setting for Damhead Creek 2 and would, as a
consequence, reduce the prominence of Damhead Creek 2 in these viewpoints.
Kingsnorth Business Park would be partially screened in views from the west by the
existing developments in the area, including Damhead Creek CCGT Power Station,
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Kingsnorth Units 1 – 4, and the Kingsnorth Industrial Estate. Damhead Creek 2 and
Kingsnorth Units 5 and 6 would provide further screening. In views from the south,
the lower (shorter) level Kingsnorth Business Park development would not increase
the impact of Damhead Creek 2 as it would be barely visible.
Damhead Creek 2 plus the Kingsnorth Business Park and Kingsnorth Units 5
and 6
12.12.9
The cumulative impact of all three developments would be significant, as all three
developments would appear as a single area of industrial development, with little or
no visual separation between each development. This will have the effect of
expanding the existing industrial area over a significantly larger expanse. This of
course does not mean that the impact is not appropriate as the entire area of the
cumulative development is entirely located within an area designated as industrial
land by Medway Council.
12.12.10
The impact of Damhead Creek 2 in isolation would be reduced were Kingsnorth 5 and
6 and Kingsnorth Business Park to be constructed as the industrial setting of the
Development would increase in terms of both the area and scale of development.
The presence of these structures would increase the sense that the land was
industrial in nature and setting and from certain view points would partially or entirely
obscure the proposed Damhead Creek 2 plant.
12.12.11
It is not considered that the construction of the Damhead Creek 2 would represent a
significant impact to the surrounding area additional to the Kingsnorth Business Park
and Kingsnorth 5 and 6 were these projects to be constructed.
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13
ECOLOGY
13.1
Summary
13.1.1
An ecological assessment has been undertaken based on a detailed desk study and
subsequent field surveys. A Phase 1 Habitat Survey was undertaken in 2006 which
covered Area 1 of the Damhead Creek 2 site and the existing mitigation land. A
number of dedicated Protected Species Surveys were carried out thereafter. Areas 2
and 3 of the Damhead Creek 2 site were subject to separate ecological assessments
in 2007. In addition, consultation with various parties including Natural England and
the RSPB was undertaken to help inform this assessment.
13.1.2
A portion of the Damhead Creek 2 site borders an area of mitigation land which
comprises neutral to calcareous grassland. This area has been established and
maintained as part of the Damhead Creek Power Generation Development. This
area is shown in Figure 1 of the Phase 1 Habitat Survey Report, written by Penny
Anderson Associates Ltd. in 2007 which is included in Appendix G of this ES.
13.1.3
Further to the south of the Damhead Creek 2 site lies the existing Kingsnorth Power
Station (Kingsnorth Units 1 to 4), which comprises buildings and hardstanding
surfaces. This consists of smaller areas of habitat including semi-improved neutral
and amenity grasslands with scattered trees and shrubs. To the north lies the
existing Kingsnorth Industrial Estate and to the west the existing Damhead Creek
CCGT Power Station.
13.1.4
drainage ditches. These drainage ditches drain naturally through the strata and into
the Damhead Creek. The Damhead Creek itself flows north east and east, into East
Hoo Creek, which subsequently flows into the River Medway, approximately 2 km
east of the Damhead Creek 2 site boundary.
13.1.5
The Medway Estuary and Marshes Special Protection Area (SPA), Ramsar Site and
Site of Special Scientific Interest (SSSI) are located adjacent to the south eastern
most areas of the Damhead Creek 2 site. In addition, three SPAs, three Ramsar
Sites, eight SSSIs, one Environmentally Sensitive Area (ESA) and one National
Nature Reserve (NNR) exist within 10 km of the Damhead Creek 2 site boundary.
The location of these sites can be seen on Figure 13.1 to 13.4.
13.1.6
Likely significant environmental impacts have been identified for a number of
ecological receptors. These include; the Medway Estuary and Marshes SPA /
Ramsar / SSSI, bats, reptiles, breeding birds and their associated habitats. Where
this is the case, mitigation measures have been proposed to reduce such likely
significant environmental impacts. No direct loss of habitat to any designated sites
will occur as a result of Damhead Creek 2.
13.1.7
Two relatively common species of bat were found to be using the Damhead Creek 2
site for foraging / commuting although no roost sites were identified. As such,
protection measures to be used to reduce the impact on bats in the area during the
construction and operational phases of Damhead Creek 2 are to include appropriate
directional lighting.
13.1.8
Relatively wide spread reptile species, including slow worms and common lizards,
were found to be present in medium to high numbers. However, Damhead Creek 2
will not form a barrier to the commuting routes of the reptiles. Mitigation to reduce the
impact on reptiles will include the formation of compensatory habitats. In addition,
employment of reptile fencing and an adequate capture effort has been proposed to
protect reptiles from harm during construction.
13.1.9
Water voles are present in many of the water bodies within and around the Damhead
Creek 2 site. The potential effects to water voles arising during the construction
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include permanent and temporary habitat loss, habitat fragmentation, disturbance and
increased risk of mortality via site clearance activities. Mitigation of the potential
impacts to water voles will be implemented that will also include regular surveys to
monitor status. Through the effective implication of these methods Damhead Creek 2
is likely to have little adverse effect on the species
13.1.10
The potential significant effects to breeding birds resulting from the construction
include permanent and temporary loss of breeding and foraging habitat, disturbance,
and increased risk of mortality via site clearance activities. In terms of mitigation,
vegetation removal will be undertaken outside the breeding season (March to late
September for most species) or if this is not possible a nest check survey will be
required to identify the absence of breeding birds before habitat clearance can be
implemented. If these procedures are followed, the potential impacts upon birds are
considered to be negligible.
13.1.11
Landscaping and habitat creation is proposed to replace the loss of habitat of local or
higher value.
13.1.12
Further significant environmental impacts may potentially arise as a result of the
Damhead Creek 2 development on great crested newts. There is currently no
evidence of the presence of this species on the DHC2 site; however, as there is
knowledge of the presence in the surrounding area precautionary principles have
been suggested during construction to account for the potential for great crested
newts.
13.1.13
There is no badger setts located in the local vicinity of the Damhead Creek 2 site.
13.1.14
Net ecological gain for the Damhead Creek 2 site, in line with planning policy, will
include the translocation of aquatic invertebrates, in addition to the enhancement of
habitats for terrestrial invertebrates and reptiles through topographical alterations and
increase of size of suitable habitat. The implementation of this should ensure that the
Damhead Creek 2 development has no likely significant ecological impact.
13.2
Introduction
13.2.1
This Section addresses the ecology and nature conservation of the Damhead Creek 2
site and surrounding area in relation to the development proposals. It reviews and
assesses the baseline ecological status of the Damhead Creek 2 site and surrounding
area and identifies those features of conservation interest or importance that require
consideration in the assessment with regards to potential impacts resulting from the
Damhead Creek 2 development.
13.3
13.3.1
CC3
Resource Use
CC8
Green Infrastructure
NRM5
Conservation and Improvement of Biodiversity
NRM8
Coastal Management
KTG7
Green Initiatives
EN3
International and National Wildlife Designations
EN6
Protecting and Enhancing Countryside Character
EN7
County and Local Wildlife Designations
EN8
Protection, Conservation and Enhancement of Biodiversity
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EN12
River Corridors
BNE22
Environmental Enhancement
BNE35
International and National Nature Conservation Sites
BNE36
Strategic and Local Nature Conservation Sites
BNE37
Wildlife
BNE38
Wildlife Corridors and Stepping Stones
BNE39
Protected Species
13.4
13.4.1
The methodology used within this Section for the ecological assessment is based on
guidance issued by the Institute of Ecology and Environmental Management1 (IEEM).
The method involves five key stages:
Stage 1: Consultations;
Stage 2: Baseline Studies and Evaluation of Ecological Receptors;
Stage 3: Identification of Valued Ecological Receptors;
Stage 4: Identification and Characterisation of Potential Impacts; and
Stage 5: Assessment of Impact Significance.
13.4.2
These stages and their associated methodologies are described below.
Stage 1: Consultations
13.4.3
During the ecological assessment, the following statutory and non-statutory bodies
were consulted:
Natural England (NE); and
Royal Society for the Protection of Birds (RSPB).
13.4.4
Responses from these consultations are incorporated within Stage 2 of the impact
assessment, which details the Baseline Studies and Evaluation of Ecological
Receptors.
Stage 2: Baseline Studies and Evaluation of Ecological Receptors
13.4.5
Baseline information regarding ecological features including sites of importance for
nature conservation, species populations, species assemblages and habitats was
obtained from several key sources. These included desk studies and ecological
surveys. Details of these studies and surveys are given below:
Desk Studies
13.4.6
The desk studies included a review of existing statutory sites of nature conservation
interest to help indicate any existing nature conservation interest within 10 km of the
Damhead Creek 2 site. This included Sites of Special Scientific Interest (SSSIs),
Special Protection Areas (SPAs), Special Areas of Conservation (SACs) and National
Nature Reserves (NNRs). This helped to ensure that sites that might be subject to air
quality affects were identified and considered in the assessment..
13.4.7
In addition, protected and notable species records within 2 km of the Damhead Creek
2 site were requested from the following groups;
1
IEEM (2006) Guidelines for Ecological Impact Assessment in the United Kingdom.
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Kent & Medway Biological Records Centre (KMBRC). The centre holds records
from the following organisations:
Kent Wildlife Trust (KWT);
Kent Bat Group;
Butterfly Conservation Trust; and
Kent Mammal Group.
West Kent Badger Group.
13.4.8
Published sources of information were consulted to gain further knowledge of wildlife
and conservation issues in the wider area. These sources included: National and
Local Biodiversity Action Plans (UKBAP and LBAP); National Biodiversity Network
(NBN) Databases; the MAGIC database; and, National Protected Species Surveys.
Of these, the Kent LBAP reflects the aims and objectives of the national plans for the
habitats and species found in the local area.
13.4.9
Additional published data was reviewed from the Environmental Statement and
Technical Reports for the neighbouring Kingsnorth Business Park by Goodman
Developments Limited. These were undertaken by Middlemarch Consultants. These
ecology surveys included assessment of the land located in Areas 2 and 3 of the
Damhead Creek 2 site and also of land further to the east of the Damhead Creek 2
site. Brief details of these surveys are given below.
Ecological Surveys
13.4.10
A range of ecological surveys have been carried out to inform the baseline.
13.4.11
A number of ecological surveys were undertaken by Penny Anderson Associates Ltd
(PAA), with the help of specialist sub consultants. These are mostly concerning
Area 1 of the Damhead Creek 2 site and the existing mitigation land. The surveys
undertaken include:
Phase 1 Habitat Survey
This was undertaken in September 2006, and May to June 2007. This survey
used standard methodology2 but was extended for use in the environmental
assessment3.
Invertebrate Surveys of Terrestrial and Aquatic Habitats
These were undertaken June, July and September 2006 within key habitat areas
of Area 1 of the Damhead Creek 2 site.
Great Crested Newt Survey
The was undertaken during May and June 2006 and April, May and June 2007.
It surveyed all suitable ponds within 500 m of the Damhead Creek site boundary.
Reptile Survey
This was undertaken during June to October 2006 and May and June 2007
within the Damhead Creek 2 site and additional areas to the north-west of the
Breeding Bird Survey
This was undertaken during April, May and June 2007 and included targeted
surveys for: barn owl; black redstart; harrier species; peregrine; and, nightingale.
2
Joint Nature Conservation Committee (1993) Handbook for Phase 1 Habitat Survey - A Technique for Environmental Audit,
Joint Nature Conservation Committee, Peterborough.
3 Institute of Environmental Assessment (1995) Guidelines for Baseline Ecological Assessment, Spon, London.
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Wintering and Passage Bird Surveys
These were undertaken during February 2007 and March, April and May 2007.
An additional winter bird survey was undertaken between October 2008 and
March 2009.
Preliminary Daytime Bat Surveys, followed up with Evening Surveys
These were undertaken in August and September 2006 to identify any roosts in
the derelict pump house on the Damhead Creek 2 site and to ascertain the level
of foraging activity within the study area and the species present.
Water Vole Survey
This was undertaken in November 2006 along the perimeter drain to the south of
the study area at the Damhead Creek 2 site.
Badger Survey
This was undertaken in October 2006 within the study area (excluding the car
park area to the north) on the Damhead Creek 2 site.
13.4.12
Full details of the above habitat and species survey methodologies, including maps
showing the survey areas, are contained within Volume 2, Appendix G.
13.4.13
In addition to the above, ecological surveys were carried out by Middlemarch
Consultants for the Environmental Statement and Technical Reports for the
neighbouring Kingsnorth Business Park proposed by Goodman Developments
Limited. These ecology surveys included assessment of the land located in Areas 2
and 3 of the Damhead Creek 2 site and also of land further to the east of the
Damhead Creek 2 site. These included:
A Phase 1 Habitat Survey and Desk Study
Breeding Bird Survey
Wintering Bird Survey
Reptile Survey
Great Crested Newt Presence/Absence Survey
Survey of Bat Foraging Activity
Badger Survey
Invertebrate (both Terrestrial and Aquatic) Survey of Selected Taxa
Water Vole Survey
Brown Hare Survey
Phase 2 Habitat Survey of Selected Habitats that demonstrated high levels of
Floral Diversity
Assessment of Hedges against the Hedgerow Regulations.
13.4.14
It should be noted that only the details of these surveys as included within the
Kingsnorth Business Park Environmental Statement were reviewed as part of this
assessment, and as such the individual survey reports are not appended to this ES.
13.4.15
A summary of the findings of all the above surveys is presented in this Section.
13.4.16
In this assessment, both existing and future predicted baseline conditions are
considered. As a result, the description and valuation of ecological features requires
account to be taken of any likely changes, such as: trends in the population size or
distribution of species; likely changes to the extent of habitats; and, the effects of
other proposed developments or land-use changes.
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Stage 3: Identification of Valued Ecological Receptors
13.4.17
It is impractical and inappropriate for an assessment of the ecological effects of a
proposed development to consider every species and habitat that may be affected.
Instead, it focuses on ‘Valued Ecological Receptors’ (VER). VERs are species and
habitats present within the zone of influence of the proposed development that are of
sufficiently high value that an effect upon them as a result of the proposed
development could be considered to be significant.
13.4.18
The value of sites, populations of species, species assemblages and habitats were
evaluated with reference to their:
Importance in terms of ‘biodiversity conservation’ value (which relates to the
need to conserve representative areas of different habitats and the genetic
diversity of species populations); and,
Legal status.
13.4.19
For the purposes of this assessment sites, species populations, species assemblages
and habitats were valued using the following geographical scale:
International
European
UK
National (i.e., England)
Regional
County
District
Local
Neighbourhood.
13.4.20
The valuation of sites makes use of established value systems. Therefore SSSIs are
of national importance, whereas County Wildlife Sites are of county importance.
However, the professional judgement of an ecologist is required for the valuation of
sites of less than district value.
13.4.21
The valuation of populations of species populations, assemblages of species and
habitats uses accepted criteria. Examples of these criteria are described below.
Species Populations.
The importance of populations is evaluated on the basis of their size, recognised
status (e.g., published lists of species of conservation concern and Biodiversity
Action Plan (BAP) status) and legal protection status. For example, bird
populations exceeding 1 per cent of published biogeographic populations are
considered to be of international importance, and those exceeding 1 per cent of
published national populations are considered to be of national importance.
Species Assemblages.
In some instances, it is the species assemblage that is of importance. Criteria
used to evaluate the importance of assemblages include SSSI selection criteria.
For further details, Fuller4 provides a framework for evaluating the relative
importance of bird assemblages.
4
Fuller R. J. (1980) A Method for Assessing the Ornithological Interest of Sites for Conservation. Biological Conservation 17 P229-239
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Habitats.
Criteria for the evaluation of habitats and plant communities includes: Annex III of
the EC Habitats Directive ’Guidelines for the Selection of Biological SSSIs’; and,
where available, Local Authority and Wildlife Trust criteria for the selection of
Local Sites (e.g., County Wildlife Sites). Legal protection status is also a
consideration for certain habitats.
13.4.22
IEEM guidelines on ecological impact assessment note the difficulty of devising
valuation criteria that can be consistently applied to designated sites, habitats and
species in the same way in all parts of the country. They therefore recommend an
approach to valuation that involves teasing apart the different values that can be
attached to the ecological receptors under consideration.
13.4.23
Examples of the sorts of criteria used in the valuation process are summarised in
Table 13.1. This has been adapted from a similar table included in several of the
earlier drafts of the IEEM guidelines.
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TABLE 13.1: EXAMPLES OF CRITERIA USED TO EVALUATE ECOLOGY
RECEPTORS
Level of Value
Examples of Definitions
International/European
An internationally important site. For example:
A Special Protection Area (SPA), Special Area of Conservation
(SAC), RAMSAR site, or a site considered worthy of such designation; or
A regularly occurring population of an internationally important
species, such as those listed on Annex IV of the Habitats Directive.
UK/National
A nationally designated site. For example:
A SSSI, or a site considered worthy of such designation;
A feature identified as of priority in the UK BAP;
Any regularly occurring populations of a nationally important
species, such as those listed on Schedules 5 and 8 of the Wildlife &
Countryside Act (1981); or
A viable area of a habitat type listed in Annex I of the Habitats
Directive, or smaller areas of such habitat which are essential to maintain
the viability of a larger whole.
Regional/County
These include:
Areas of internationally or nationally important habitats which are
degraded but are considered readily restored;
Viable areas of key habitat identified in Local BAPs, or smaller
areas of such habitat which are essential to maintain the viability of a
larger whole;
A site designated as a Wildlife Site or Site of Nature
Conservation Interest (SNCI); or
A regularly occurring, locally significant number of a nationally
important species.
District
These include:
Areas of habitat identified in a sub-county (District or Borough) or
in the relevant Natural Area profile;
District sites that the Designating Authority has determined meet
the published ecological selection criteria for designation, including Local
Nature Reserves;
Sites or features that are scarce within the District or Borough or
which appreciably enrich the District or Borough habitat resource; or
A diverse or ecologically valuable hedgerow network.
Local
These include:
Areas of internationally or nationally important habitats which are
degraded and have little or no potential for restoration; or
A good example of a common or widespread habitat in the local
area
Neighbourhood (site and its vicinity,
including areas of habitats
contiguous with or linked to those
on site)
These include:
Areas of heavily modified or managed vegetation of low species
diversity or low value as habitat to species of nature conservation interest;
or
Common and widespread species
13.4.24
Within this assessment, sites, species populations, species assemblages and habitats
are considered to be Valued Ecological Receptors (VER) if they meet the following
minimum level of importance:
Sites – local importance;
Species populations and assemblages – local importance; and
Habitats – local importance.
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13.4.25
It is considered that no significant effect can occur to features of lesser importance
than those listed above, except where a feature has high social, economic, supporting
or secondary value.
13.4.26
The description and valuation of ecological features will take account of any likely
changes. For example, these include: trends in the population size or distribution of
species; likely changes to the extent of habitats; and, the effects of other proposed
developments or land-use changes.
Stage 4: Identification and Characterisation of Potential Impacts
13.4.27
The potential likely ecological impacts of Damhead Creek 2 during construction and
operation, are identified and characterised. In identifying these impacts, a number of
parameters were taken into account. The parameters used to determine the nature of
the impact included:
Negative or Positive Effect
Whether the effect of the impact would result in net loss or degradation of a VER
or whether it would enhance or improve it. Impacts are considered to be
negative if the construction or operations cause: a detrimental effect on a
vulnerable ecological receptor; a potential reduction in the conservation
status/ecological value of a habitat/species population; and/or, a site’s integrity5
to become compromised. Impacts are considered to be positive if the
construction or operational activities cause: a non-valued ecological receptor to
become valued; the restoration of favourable conservation status for a
habitat/species population; and/or, the restoration of a site’s integrity where
previously it had been undermined.
Magnitude
The size or intensity of the effect measured in relevant terms. For example: the
number of individuals lost or gained; area of habitat lost or created; or, the
degree of change to existing conditions such as noise or lighting levels. The
magnitude of impacts is further discussed below.
Extent
The spatial scope of the effect. For example: the physical area affected; or, the
geographical pattern of the effect.
Duration
The length of time over which the effect occurs.
Reversibility
The extent to which effects are reversible, either spontaneously or through active
mitigation.
Timing and Frequency
Consideration of the timing of events in relation to ecological change. Some
effects may be of greater significance if they take place at certain times of year,
such as during the breeding bird season. The extent to which an effect is
repeated may also be of importance.
Note on Magnitude of Potential Impacts
13.4.28
Ecological receptors are usually sites, habitats, species assemblages or communities,
or populations or groups of a species. Effects can be permanent or temporary, direct
or indirect, and can be cumulative. These factors are brought together to assess the
magnitude of the impact on particular VERs and, wherever possible, the magnitude of
5
The integrity of the designated sites is defined by the IEEM as “the coherence of ecological structure and function, across a
site’s whole area, that enable it to sustain the habitat, complex of habitats and/or levels of populations of species for which it
was classified.”
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the impact is quantified. Professional judgment is then used to assign the effects on
the receptors to one of four classes of magnitude, defined in Table 13.2.
TABLE 13.2: DEFINITION OF MAGNITUDE
Magnitude
Definition
High
A permanent or long-term effect on the extent or size or integrity of a site,
habitat, species assemblage or community, population or group.
If adverse, this is likely to threaten sustainability. However if beneficial,
this is likely to enhance conservation status.
Medium
A permanent or long-term effect on the extent or size or integrity of a site,
habitat, species assemblage or community, population or group.
If adverse, this is unlikely to threaten sustainability. However, if beneficial,
this is likely to be sustainable but is unlikely to enhance its conservation
status.
Low
A long-term reversible effect on a site, habitat, species assemblage or
community, population or group whose magnitude is detectable but will
not threaten its integrity.
Negligible
A short-term reversible effect on the extent or size or integrity of a site,
habitat, species assemblage or community, population or group that is
within the normal range.
13.4.29
In the ecological assessment, potential impacts are initially characterised in the
absence of any mitigation, except where this is integral to the design of Damhead
Creek 2. Any additional mitigation or compensation proposed is identified and its
likely effectiveness is assessed.
13.4.30
Within the assessment, an indication of the confidence with which predictions of
potential impacts are made is also given. When predicting confidence, a four point
scale is normally employed. Within this scale the confidence levels are:
Certain/Near-Certain
Probability estimated at 95 per cent chance or higher
Probable
Probability estimated at above 50 per cent, but below 95 per cent
Unlikely
Probability estimated above 5 per cent, but less than 50 per cent
Extremely Unlikely
Probability estimated at less than 5 per cent
Stage 5: Assessment of Impact Significance
13.4.31
The procedure used for assessment of the significance of the effects of the proposed
development focuses on the integrity of each ecological receptor. The decision as to
whether the integrity of an ecological receptor likely to be affected is made using
professional judgement of a suitably qualified ecologist based on an analysis of the
predicted effects of Damhead Creek 2.
13.5
Overview of the Damhead Creek 2 Site
13.5.1
The Damhead Creek 2 site is situated on the southern edge of the tongue of land
between the Thames and Medway estuaries known at the Hoo Peninsula. The
Damhead Creek 2 site area is 23.8 ha in size.
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13.5.2
A portion of the Damhead Creek 2 site borders an area of existing mitigation land
which comprises neutral to calcareous grassland. This area has been established
and maintained as part of the Damhead Creek Power Generation Development. This
area is shown in Figure 1 of the Phase 1 Habitat Survey Report, written by Penny
Anderson Associates Ltd. in 2007 which is included in Appendix G of this ES.
13.5.3
Further to the south of the Damhead Creek 2 site lies the existing Kingsnorth Power
Station (Kingsnorth Units 1 to 4), which comprises buildings and hardstanding
surfaces and smaller areas of habitat including semi-improved neutral and amenity
grasslands with scattered trees and shrubs. To the north lies the existing Kingsnorth
Industrial Estate and to the west the existing Damhead Creek CCGT Power Station.
13.5.4
drainage ditches, which flow into Damhead Creek itself. Damhead Creek flows
northeast and east from the Damhead Creek 2 site, into East Hoo Creek, which
subsequently flows into the River Medway, approximately 2 km east of the Damhead
Creek 2 site boundary.
13.5.5
The area surrounding the Damhead Creek 2 site is characterised by the mudflats and
wetland margins of the Medway Estuary, in addition to several industrial
developments. The industrial developments include large sites at the Isle of Grain,
located approximately 5 km northeast of the Damhead Creek 2 site. An industrial
railway line runs west-east across the Hoo Peninsula, passing approximately 750 m
north of the Damhead Creek 2 site at its nearest point, and several minor roads
connect the industrial sites and small hamlets and farmsteads to the nearby town of
Hoo St. Werburgh (approximately 3 km west of the Damhead Creek 2 site) and to the
A228 (to the north and west of the Damhead Creek 2 site) and other major road
networks in the local area.
Designated Sites
Statutory Designated Sites
13.5.6
The Medway Estuary and Marshes Special Protection Area6 (SPA), Ramsar7 Site and
Site of Special Scientific Interest8 (SSSI) are located adjacent to the Damhead Creek
2 site. In addition, three SPAs, three Ramsar sites, one Environmentally Sensitive
Area (ESA)9, eight SSSIs and one National Nature Reserve (NNR) occur within 10 km
of the Damhead Creek 2 site boundary. Details of these sites are summarised below
in Table 13.3.
6
Special Protection Areas (SPAs) are designated as important sites in accordance with Article 4 of the EU Directive on the
conservation of wild birds (79/409/EEC), also known as the Birds Directive, which came into force in April 1979. SPAs are
classified for rare and vulnerable birds, listed in Annex I to the Birds Directive, and for regularly occurring migratory species.
The sites are then protected under the Conservation (Natural Habitats & c. Regulations 1994) as amended.
7
Ramsar sites are wetlands of international importance designated under the Ramsar convention 1971.
8
Site of Special Scientific Interest (SSSI) are notified under Section 28 of the Wildlife and Countryside Act 1981 as amended.
SSSI are examples of the country's very best wildlife and geological sites
9
Environmentally Sensitive Area (ESA). Land is designated by The Department of Environment, Food and Rural Affairs
(DEFRA) when it is of particularly high landscape, wildlife or historic value.
June 2009
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ECOLOGY
TABLE 13.3: STATUTORY DESIGNATED SITES WITHIN 10 km OF THE DAMHEAD CREEK 2 SITE
Designated Site
Medway Estuary and Marshes SPA
Size (ha)
Distance from Damhead
Creek 2 Site
4684
Adjacent
Description
A wetland of international importance, supporting at least 20,000 breeding wildfowl, and
over 60,000 wildfowl during the winter months.
The site is especially important for breeding avocet (Recurvirostra avosetta) and little
tern (Sternula albifrons), and several wintering species including little grebe
(Tachybaptus ruficollis), dark-bellied brent goose (Branta bernicla bernicla), shelduck
(Tadorna tadorna), pintail (Anas acuta), ringed plover (Charadrius hiaticula), grey plover
(Pluvialis squatarola), dunlin (Calidris alpina alpina), avocet, redshank (Tringa tetanus),
curlew (Numenius arquata), great crested grebe (Podiceps cristatus), cormorant
(Phalacrocorax carbo), wigeon (Anas Penelope), teal (Anas crecca), oystercatcher
(Haematopus ostralegus), lapwing (Vanellus vanellus), black-tailed godwit (Limosa
limosa) and whimbrel (Numenius phaeopus).
Medway Estuary and Marshes
Ramsar Site
4697
Adjacent
The site supports a number of rare plant and animal species, including ten nationally
scarce plants, 12 British Red Data Book species of wetland invertebrates and a
significant number of non-wetland British Red Data Book species as well. The site
regularly supports almost 50,000 waterfowl.
Qualifying species include breeding grey plover and redshank and overwintering darkbellied brent goose, shelduck, northern pintail, ringed plover, red knot (Calidris canutus)
and dunlin.
Medway Estuary and Marshes SSSI
Dalham Farm SSSI
Tower Hill to Cockham Wood SSSI
June 2009
6840
Adjacent
This site forms the largest area of intertidal habitats of nature conservation value in
Kent, including saltmarsh, grazing marsh, scrub, reedbeds and sand dune, and shell
and sand beaches. It is representative of the estuarine habitats of the North Kent coast.
It is believed to be the most important area in North Kent for wintering wildfowl.
9
4 km north-west
This site, designated for its geological value, is one of very few undisturbed areas which
show mass movement phenomena on low-angled, inland slopes of London Clay.
Dalham Farm illustrates what is possibly the lowest angled slope failure in Great Britain
and is important in demonstrating slope degradation in the absence of coastal erosion
and removal of material from the base.
47.9
4 km west
This site is designated for both its biological and geological interest. It supports
woodland representative of that on Tertiary deposits in Kent, including neglected
coppice, principally ash (Fraxinus excelsior), with oak (Quercus robur) standards, and
supports a rich insect fauna. In addition, Upnor Quarry exposes a complete Tertiary
stratigraphic sequence.
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ECOLOGY
Designated Site
Size (ha)
Creek 2 Site
Description
Northward Hill SSSI and High Halstow
NNR
52.5
4 km north-west
This site supports the largest heronry in Britain, of over 200 pairs. Also of importance
on the site is the diverse breeding bird community and insect fauna, in particular moths
and butterflies. The site comprises mixed deciduous woodland and scrub with some
open areas of grassland and bracken (Pteridium aquilinum). A number of small ponds
are also present, along with a few open ditches.
Chattenden Woods SSSI
133
4 km north-west
This woodland is representative of coppice-with-standards woodland on the London
Clay, which is a scarce habitat in Kent away from the Blean Woods. The site is also of
importance for its breeding birds. Rough Shaw, an area of neutral grassland with
scattered scrub, forms a valuable addition to the woodland.
Thames Estuary and Marshes Ramsar
Site
5588
6 km north-west
The site supports one endangered plant species and at least 14 nationally scarce plants
of wetland habitats. The site also supports more than 20 British Red Data Book
invertebrates. The site regularly supports over 45,000 waterfowl.
Qualifying species include breeding ringed plover and black-tailed godwit and overwintering grey plover, red knot, dunlin and common redshank.
Thames Estuary and Marshes SPA
4839
6k m north-west
A wetland of international importance, supporting at least 20,000 breeding wildfowl, and
over 33,000 wildfowl during the winter months. The site is especially important for
avocet, ringed plover and hen harrier (Circus cyaneus), and several other wintering
species including redshank, black-tailed godwit, dunlin, lapwing, grey plover, shoveler
(Anas clypeata), pintail, gadwall (Anas strepera), shelduck, white-fronted goose (Anser
albifrons), little grebe, ringed plover, avocet and whimbrel. Large parts of the South
Thames Estuary and Marshes Ramsar/SPA are also designated as an ESA.
South Thames Estuary and Marshes
SSSI
5449
6 km north-west
The site forms a major component of the Greater Thames Estuary, consisting of an
extensive mosaic of grazing marsh, saltmarsh, mudflats and shingle characteristic of the
estuarine habitats of the north Kent marshes, along with freshwater pools and some
areas of woodland. The site supports outstanding numbers of waterfowl with total
counts regularly exceeding 20,000 individuals. Many species regularly occur in
nationally important numbers and some species regularly use the site in internationally
important numbers. The breeding bird community is also of particular interest. The
diverse habitats within the site support a number of nationally rare and scarce
invertebrate species and an assemblage of nationally scarce plants.
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ECOLOGY
Designated Site
Queendown Warren SAC
Size (ha)
Creek 2 Site
14
10 km south
Description
Queendown Warren consists of CG3 Bromus erectus grassland. It contains an
important assemblage of rare and scarce species, including early spider-orchid (Ophrys
sphegodes), burnt orchid (Orchis ustulata) and man orchid (Aceras anthropophorum).
The SAC Priority feature is “6211 Semi-natural dry grasslands and scrubland on
calcareous substrates".
Queendown Warren SSSI
22
10 km south
In the grassland and woodland of this site two nationally rare plant species occur. In
addition an outstanding assemblage of plants is present. The grassland and woodland
of this site are on the south-facing slope of a dry chalk valley. The grassland is largely
dominated by upright brome (Bromus erectus) and sheep’s fescue (Festuca ovina) with
numerous plants characteristic of grazed but otherwise undisturbed chalk grassland.
Notable species include the rare early spider orchid. Another rare plant present is
meadow clary Salvia pratensis. The grassland is also rich entomologically. Potter’s
Wood is mainly sweet chestnut coppice with oak standards. Among scarcer species of
the ground flora are the ladyorchid (Orchis purpurea) and yellow bird’s-nest (Monotropa
hypopitys).
Benfleet and Southend Marshes
Ramsar site
2251
10 km north
Benfleet and Southend Marshes comprise an extensive series of saltmarshes, mudflats,
and grassland which support a diverse flora and fauna, including internationally
important numbers of wintering waterfowl.
Benfleet and Southend Marshes SPA
2251
10 km north
This site supports populations of European importance of the following migratory
species:
On passage: Ringed Plover, 800 individuals representing at least 1.6% of the
Europe/Northern Africa - wintering population.
Over winter: Dark-bellied Brent Goose, 3,819 individuals representing at least 1.3% of
the wintering Western Siberia/Western Europe population; Grey Plover, 3,789
individuals representing at least 2.5% of the wintering Eastern Atlantic wintering
population;
Knot, 8,850 individuals representing at least 2.5% of the wintering North-eastern
Canada/ Greenland/Iceland/ North-western Europe population.
Assemblage qualification: A wetland of international importance.
The area qualifies by regularly supporting at least 20,000 waterfowl. Over winter, the
area regularly supports 34,789 individual waterfowl including: Dunlin, Ringed Plover,
Oystercatcher, Knot, Grey Plover, and Dark-bellied Brent Goose.
June 2009
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ECOLOGY
Designated Site
Benfleet and Southend Marshes SSSI
Size (ha)
Creek 2 Site
2099
10 km north
Description
Benfleet and Southend Marshes comprise an extensive series of salt marshes,
mudflats, scrub and grassland which support a diverse flora and fauna. The southfacing slopes of the downs, composed of London Clay capped by sand, represent the
line of former river cliffs with several re-entrant valleys. At their foot lies reclaimed
marshland, with its associated dyke system, based on alluvium. Outside the sea walls
there are extensive salt marshes and mud-flats, on which wintering wildfowl and waders
reach both nationally and internationally important numbers. Nationally uncommon
plants occur in all of the habitats and parts of the area are of outstanding importance for
scarce invertebrates. Dominant grassland species are typical of neutral to acidic
conditions.
The ponds and dykes exhibit a transition between fresh and brackish water and support
a diversity of flora and fauna. The great crested newt and scarce emerald damselfly
(Lestes dryas) are present.
The mud-flats are colonized by eel-grasses (Zostera marina) and (Z. noltii) which,
together with dense patches of Enteromorpha and the rich invertebrate fauna within the
mud, provide food for thousands of birds which overwinter on this shoreline. Three
species (dark-bellied brent goose, grey plover and knot) occur in internationally
important numbers whilst three species, (dunlin, redshank and ringed plover), are
present at nationally important levels. They feed along the entire length of the flats; the
major high tide roosts are found on the salt marsh at Two Tree Island and Canvey Point.
Part of this site is also a National Nature Reserve.
June 2009
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ECOLOGY
13.5.7
In addition to these designated sites, several sites within 5 km of the Damhead Creek
2 site boundary support ancient woodland1. There are two areas of ancient woodland
near Fenn Street, approximately 2.5 km north-west of the Damhead Creek 2 site, and
six areas of ancient woodland of varying size at Chattenden Woods SSSI and nearby
(the closest of these sites is approximately 3 km to the west of the Damhead Creek 2
site). There is also ancient woodland at Tower Hill to Cockham Wood SSSI,
approximately 4 km southwest of the Damhead Creek 2 site.
13.5.8
Figure 13.1 to 13.4 illustrates the locations of the designated sites in relation to the
Habitats and Species
13.5.9
13.5.10
The baseline information presented in this Section draws on both the surveys
undertaken by PAA and also by Middlemarch Consultants for the neighbouring
Kingsnorth Business Park proposed by Goodman Developments Limited. In line with
the rest of the ES, the Damhead Creek 2 site has been separated into three broad
areas as shown in Figure 2.1. In summary:
Area 1.
6.2 ha of land lying mainly to the east of the existing Damhead Creek CCGT
Power Station. This is the location of the Damhead Creek 2 site and is
shaded in red on Figure 2.1.
Area 2.
Power Station. This is the location of a proposed 400 kV substation which
will export the electrical energy generated by Damhead Creek 2 to the
National Grid Transmission Network. This area is shaded in green on
Figure 2.1.
Area 3.
construction phase of the Development. This area may also be set aside
for the installation of Carbon Capture and Storage equipment in the future,
and thus may be reserved for any such development. The remainder of the
area would be dedicated to ecological mitigation including additional ponds
and habitat enhancement. All land in this area has previously been used to
dispose of the fly ash from the nearby Kingsnorth Power Station. It is
surrounded by ecological mitigation land associated with the development
of the existing Damhead Creek CCGT Power Station, and currently contains
a number of small ponds. This area is shaded blue on Figure 2.1 .
Conduits for Damhead Creek 2 between these areas will be predominantly along
existing highways or hand-standing unless otherwise mentioned. It should be noted
that Areas 1 to 3 referred to in this Section are not referenced in the appended
ecology documents.
Area 1 Habitats and Flora
13.5.11
The desk study conducted by PAA identified records for a number of plant species
which were nationally scarce2 and rare Kent species3 and Red Data Book species4.
Many of the species were predominately associated with saltmarsh habitats
associated with the Medway Estuary and Marshes.
1
Ancient Woodland is woodland with a proven continuity of cover for at least 230 years, identified by Nature Conservancy
Council in Inventory of Ancient and Long-established Semi-natural Woodland (NCC, 1989 and 1991).
2
Nationally Scarce are species found in 16-100 hectads in Great Britain
3
A Kent rarity is a species that occurs in 10 or fewer of the 1044 tetrads which comprise the county of Kent
4
Waite, A. (ed.), 2000, The Kent Red Data Book: A Provisional Guide to the Rare and Threatened Flora and Fauna of Kent,
Kent County Council
June 2009
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ECOLOGY
13.5.12
Area 1 was dominated by semi-improved neutral to calcareous grassland, which was
sown following the development of the existing Damhead Creek CCGT Power
Station. The northern section of the grassland supported a greater diversity of
grasses and herbs compared to the remainder of the area. The dominant grasses
were false oat-grass (Arrhenatherum elatius), bent species (Agrostis sp) and
meadow-grasses (Poa sp.) with meadow foxtail (Alopecurus pratensis) and Timothy
(Phleum pratense). The southern section supported a sward which is less herb-rich
and dominated by Arrhenatherum elatius, but with a greater number of Umbellifers
and shrubs. Species frequently recorded in this area included Alexander’s (Smyrnium
olusatrum), hemlock (Conium maculatum), hogweed (Heracleum sphondylium) and,
some, wild parsnip (Pastinaca sativa). There were also many scattered patches of
bramble (Rubus fruticosus).
13.5.13
The eastern boundary of Area 1 was less diverse, consisting of tall unmanaged
grassland, dominated by oat-grass and common couch (Elymus repens) with less
abundant Timothy, Yorkshire-fog (Holcus lanatus), Agrostis sp. and Poa sp. Frequent
mugwort (Artemisia vulgaris) and common nettle (Urtica dioica) were also present. In
the south eastern corner spoil mounds, originating from pond construction, supported
wild carrot (Daucus carota), black mustard (Brassica nigra) and hoary cress
(Lepidium draba) along with other grass species. There was a large hemlock patch to
centre. Scattered hogweed was frequent in this area and smooth tare (Vicia
tetrasperma) was locally dominant.
13.5.14
A strip of unmanaged semi-improved neutral to calcareous grassland ran along the
inside of the southern boundary of the existing Damhead Creek CCGT Power Station
development. It was similar in composition to the grassland areas described above,
but was less diverse. The grass canopy was around 40 cm tall and was dominated
by a range of common species, along with several that indicate slightly calcareous
condition (e.g., Daucus carota and vervain (Verbena officinalis).
13.5.15
Located immediately east of the Area 1 Damhead Creek 2 site boundary is the
Wetland Creation Area (WCA), developed as part of the ecological
mitigation/compensation for the existing Damhead Creek CCGT Power Station
development. The WCA was dominated by managed semi-improved neutral to
calcareous grassland. The grassland in this area was managed under a once-yearly
mowing regime, which has resulted in an increase in the diversity of the sward. In
some areas this grassland supported ruderal/disturbed ground species. Bee orchids
(Ophrys apifera) were recorded in this area.
13.5.16
Three ponds (1, 2 and 3 (as detailed in Appendix G) were found within the Wetland
Creation Area (WCA), situated immediately to the east of the Damhead Creek 2 site.
Pond 1 was created for the translocation of the rare divided sedge (Carex divisa) from
the existing Damhead Creek CCGT Power Station site. Pond 2, created at the same
time is a long linear shaped pond in the middle section of the WCA, with two small
islands at the far southern and northern ends. The western edge of the pond had
flatter areas that were becoming characterised by marshy grassland with localised
patches of soft-rush (Juncus effusus), the edges were fringed with patches of bulrush
(Typha latifolia) and sea club-rush (Scirpus maritimus), and the small islands were dry
and colonized by grasses and herbs typical of neutral soils, including cocksfoot
(Dactylis glomerata), Yorkshire fog (Holcus lanatus), yarrow (Achillea millefolium) and
bristly oxtongue (Picris echioides). Pond 3, located at the northern end of the WCA,
was created as a great crested newt refuge area during site clearance for the existing
Damhead Creek CCGT Power Station development. The pond was small, shallow
sided and entirely overgrown at the time of the survey.
13.5.17
A permanent wet ditch ran west to east along the southern boundary of Area 1 and
into the WCA before turning north-west and running through the WCA itself.
June 2009
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ECOLOGY
13.5.18
A small amount of scattered scrub consisting mainly of bramble was found at the
southern boundary of Area 1, adjacent to the ditch. A number of clumps of scrub
were also situated between the grassland strip along the southern boundary of Area 1
and the perimeter ditch, including dog rose (Rosa canina), bramble and hawthorn
(Crataegus monogyna). Some areas of planted scattered gorse (Ulex sp.) and.
broom (Cytisus sp) scrub were present in the northern proportion of WCA, and
scattered scrub was present along the eastern perimeter of the WCA.
13.5.19
A disused pump house building is located to the south-east outside of Area 1 on top
of the bund that forms the WCA eastern boundary. A concrete lined pool is located in
amongst the dense bramble scrub that surrounds the pump house.
13.5.20
Area 2 was surveyed by Middlemarch Consultants as part of the Kingsnorth Business
Park project proposed by Goodman Developments Limited.
13.5.21
Area 2 consists of an area of hard core/gravel. The floristic composition was typical
of this open, disturbed habitat, with sparsely vegetated, self-sown, neutral grassland
on coarse substrate, which in places was relatively bare. Tall herbs predominate,
with creeping thistle (Cirsium arvense), wild teasel (Dipsacus fullonum), common
fleabane (Pulicaria dysenterica), bristly ox-tongue (Picris echioides) and common
couch (Elytrigia repens). A tall, dense patch of hemlock dominated the eastern corner
of the grassland interspersed with frequent common nettle. Bramble and Rosa sp.
species had encroached from the hedge line to the north with locally abundant ground
ivy (Glechoma hederacea). A belt of young trees was planted along the southern
fence line predominately pedunculate oak (Quercus robur), ash (Fraxinus excelsior),
hawthorn, blackthorn (Prunus spinosa) and willow species.
13.5.22
A ditch lined the north eastern margin of Area 2. At the time of the survey there was a
further temporary waterbody in the northern section of this area, of irregular shape,
covering approximately 4 m 6 m. The water at the time of survey was 4 to 6 cm
deep with emergent vegetation including oak-leaved goosefoot (Chenopodium
glaucum), amphibious bistort (Persicaria amphibia) and curled dock (Rumex crispus)
(the spp. littoralis). The area was surrounded by vegetation comprising butterfly-bush
(Buddleja davidii), common fleabane (Pulicaria dysenterica), willows (Salix sp.),
golden samphire (Inula crithmoides) and great willowherb (Epilobium hirsutum).
Beyond the boundary to the north is a triangular waterbody also known as the
“Western Corridor Pond” or “Fire Pond”. Open water occupies about 80% of pond
area and fish are thought to be present. The pond is considered to be of limited
conservation interest
13.5.23
In addition, there is a water body located to the north of Area 2. This is a fire
reservoir. This does not hold any ecological value, and as such is not discussed
further in this Section.
13.5.24
Area 3 was surveyed by Middlemarch Consultants as part of the Kingsnorth Business
Park project proposed by Goodman Developments Limited
13.5.25
This area is dominated by bare ground and is separated from the WCA by a bund
which forms the western boundary of Area 3. The bund is covered with poor semiimproved grassland with some tall rudderless. Dominant species included common
couch (Elytrigia repens), false oat-grass (Arrhenathreum elatius), cocksfoot, plantain
(Plantago sp.) and clover (Trifolium sp.). A large section of the central area
comprises of the above described poor semi-improved grassland with occasional
patches of tall ruderals consisting of ragwort (Senecio jacobea), thistle (Cirsium sp.)
nettle, cow parsley (Anthriscus sylvestris), sea beet (Beta vulgaris subsp. Maritime),
teasel (Dipsacus sp.) and alexanders (Smyrnium olusatrum).
June 2009
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ECOLOGY
13.5.26
Much of the south-western part of Area 3 comprises of sparsely vegetated ground
consisting of ephemeral short perennials such as grasses Festuca sp., mosses,
common ragwort, plantain, dove’s-foot crane’s-bill (Geranium molle) and clover.
13.5.27
Five areas of open water and numerous ditches are present in Area 3 detailed within
Appendix G.
13.5.28
An area of open water is situated outside and adjacent to the north-western corner of
Area 3 with a ditch running from this open water along the base of the western bund,
approximately 1 m wide and 0.5 m deep, in a southerly direction. The central section
of Area 3 comprises three distinct large water bodies numbered for the purposes of
this report as water bodies A, B and C. A number of channels run from these water
bodies, totalling 400 m in length, containing standing water with occasional patches of
marginal vegetation. Water bodies A and B are similar in size (300 m
40 m
respectively 400 m
30 m) and are situated parallel with each other, connected
through a channel. Some marginal vegetation is present in these ponds, and parts of
their embankments are covered with scrub. Water body C is found in the northeastern section of Area 3 and has steep sides and marginal vegetation around the
edge.
13.5.29
Marginal vegetation consists mainly of common reed (Phragmites australis) and
species of reedmace (Typha sp.). Some scattered scrub is found along the banks of
the water bodies present on the Damhead Creek 2 site, consisting mainly of bramble,
gorse (Ulex europaeus), dog rose (Rosa canina), butterfly-bush (Buddleia davidii) and
some hawthorn. A patch of dense scrub is found in the north western corner of
Area 3.
Summary of the Damhead Creek 2 Site Habitats and Flora
13.5.30
In summary across the entire Damhead Creek 2 site the following broad habitats are
present:
Semi-Improved Grassland
This habitat is very common in a local, county and national context.
Notwithstanding the potential for this habitat to support protected species and/or
species of conservation interest this habitat is considered to be of neighbourhood
importance and as such is not considered further in this assessment.
Water Bodies, including: ponds; ditches; saline/brackish lagoons; and,
associated marginal habitats
These habitats are typical of the local area but are less common in a
wider/national context. Notwithstanding the potential for these habitats to
support protected species and/or species of conservation interest these habitats
are considered to be of county importance and as such considered further in this
assessment.
Scattered Scrub
Dense Scrub
Ruderal
June 2009
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ECOLOGY
Sparse Vegetated Ground
Hard Standing/Gravel
Protected and/or Notable Fauna
Badger
13.5.31
Badgers and their setts are protected under the Protection of Badgers Act (1992).
13.5.32
Licenses, either to exclude badgers from a sett or to close it if there will be direct
impact from Damhead Creek 2 are required from Natural England. Further to this,
disturbance licences are likely to be required from Natural England if the following
activities occur closer to a badger sett than the distances specified below:
Digging or scrub clearance within 10 m of an active sett;
Use of light machinery (wheeled vehicles etc.) within 20 m of an active sett; or
Basic activities and heavy machines (such as JCBs) within 30 m of a sett.
13.5.33
Disturbance under licence can normally only be undertaken between July and
November inclusive (outside of the breeding season). Under PPS 9, badger foraging
areas are additionally a material consideration in the approval of an application for
planning approval.
13.5.34
The desk studies undertaken by PAA and Middlemarch Consultants identified a
number of road traffic accident records for badgers in the 2 km search area including
two incidents on the road leading down to the existing Kingsnorth Power Station5.
13.5.35
The survey method was based on the standard approach detailed in the Mammal
Society publication Surveying Badgers6 and used during the National Badger
Survey7. This involved searching for field signs associated with badger. This
included searchs for setts, runs, foraging activity, latrines and footprints. Other signs
included in the search were scratching posts and hairs caught on fences. Using
nationally recognised sett classification criteria, all setts during the survey were
categorized as either main, annex, subsidiary or outlier. Individual badger holes were
further classified as A (active), B (partially active) or C (disused).
13.5.36
Within the Damhead Creek 2 site no badger setts were recorded. Evidence of
badgers was found in the form of one fresh latrine and a badger hair found on a gate
by a fence line. A number of runs were also present within the Damhead Creek 2
site, although these may have also been formed by a rabbit or a fox. Outside of the
Damhead Creek 2 site boundary additional signs of badger activity were recorded
including, tracks, latrines and foraging activity.
5
West Kent Badger Group
6
Harris, S. Cresswell, P and Jefferies, D. (1989) Surveying Badgers. The Mammal Society Publication No. 9 Mammal Society
7
Cresswell, P., Harris, S. and Jefferies, D.J. (1990). The History, Distribution, Status and Habitat. Requirements of the Badger
in Britain. Nature Conservancy Council, Peterborough.
June 2009
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ECOLOGY
13.5.37
The results of the surveys indicate that badgers are commuting within the Damhead
Creek 2 site. However no badger setts were found located within 30 m of the
boundaries of the Damhead Creek 2 site. The evidence recorded suggests that the
Damhead Creek 2 site is of no more than local importance to badgers.
Water Vole
13.5.38
Water voles are protected under the Wildlife and Countryside Act 1981 (as amended).
It is an offence to possess, control or sell water voles or to intentionally kill, injure or
take water voles. It is also an offence to intentionally or recklessly damage, destroy
or obstruct access to a place that water voles use for shelter or protection or disturb
water voles whilst using such a place.
13.5.39
The desk study undertaken by PAA in 2006 identified seven records of water vole
(Arvicola terrestris) in the 2 km search area including one record from the ditches
associated with the existing Kingsnorth Power Station.
13.5.40
The water vole survey methodology was based on the standard approach given in the
Water Vole Conservation Handbook8 with modifications to suit the conditions of the
Damhead Creek 2 site. Field signs searched for included latrines, feeding stations of
chewed vegetation (identified to species where possible), burrow entrances (including
those both above and below water level), runs and pathways, footprints and feeding
‘lawns’ around burrow entrances. Any sightings and sounds of water voles entering
the water were also recorded. Where found, burrows, latrines and feeding stations
were counted, as these can provide crude, though useful, indications of the relative
density and abundance of water voles. In addition to the above, a number of features
of the habitat were recorded including bank profile and substrate, width, depth and
speed of watercourse and amount of shade and vegetation cover, along with the
dominant plant species present.
13.5.41
Water vole activity surveys were undertaken along the ditch present on the southern
boundary of Area 1 during 2006. Water vole activity signs were present along the
length of the perimeter drain with the highest levels of activity being noted at the
western and eastern ends. The central 250 to 300 m stretch showed fewer signs of
activity. This lower activity appears to correspond with continuous scrub cover
creating less suitable habitat for water voles.
13.5.42
Water vole surveys have been undertaken in previous years across the area
(between 2001 and 2005) and the results of the 2006 survey indicate the overall
water vole population remains stable.
13.5.43
As part of the development of Kingsnorth Business Park four water bodies and one
ditch were surveyed for the presence of water voles by Middlemarch Consultants. Of
the surveyed water bodies three are situated within the Damhead Creek 2 site and
the other two (which includes the ditch) are located adjacent to the Damhead Creek 2
site. The surveys were undertaken in May, June and September 2007. All of the
water bodies surveyed were found to support water voles. In the water bodies within
the boundary of the Damhead Creek 2 site, latrines, burrows and grazing areas have
also been recorded.
13.5.44
In summary, the ditches adjacent to the Damhead Creek 2 site and the connected
ditches in the wider area are known to support a large population of water voles. In
light of this, the population within the Damhead Creek 2 site is considered to be of
local value and therefore when assessing the potential impacts the legislation
protecting this species will need to be considered to ensure legal compliance.
8
Strachan, R.S. & Moorhouse, T.P. (2007) The Water Vole Conservation Handbook, second edition. Wildlife Conservation
Research Unit & The Environment Agency.
June 2009
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Bats
13.5.45
It is illegal to deliberately capture, injure or kill a bat and to intentionally or recklessly
disturb bats. It is also illegal to damage, destroy or intentionally or recklessly obstruct
access to a breeding or resting place used by a bat. The legislation is contained with
the Wildlife and Countryside Act 1981 (as amended) and the Habitats Regulations
1994, (as amended).
13.5.46
The desk study completed by PAA in 2006 identified two records of bats in the search
area. The recorded species included common pipistrelle (45 kHz) (Pipistrellus
pipistrellus) and noctule (Nyctalus noctula).
13.5.47
Further surveys for bats were undertaken during 2006 at the derelict pump house on
the eastern edge of the Wetland Creation Area (WCA), to assess if the building was
used by roosting bats. Although this building is located outside of the proposed
footprint of Damhead Creek 2, consideration of the potential loss of foraging habitat
was required in the event a roost was present. A single dawn swarming survey and
two evening emergence surveys were undertaken between August and September
2006, following the guidance set out in the Bat Mitigation Guidelines9 and the Bat
Workers’ Manual10.
13.5.48
Dawn swarming surveys are targeted at trees and buildings to identify entrances to
roosts as bats tend to gather together outside a roost for several minutes just prior to
entering the roost for the day. A note of the time of swarming, the number of bats and
species, if identifiable, was taken. In addition, general bat activity on the Damhead
Creek 2 site was noted by recording the time, number and direction of bat passes in
the general area, with identification to species if possible.
13.5.49
Emergence surveys involve watching for and counting bats emerging from their
roosting sites in the evening. During the 2006 surveys two surveyors completed the
emergence surveys, positioned either side of the pump house. The surveys
commenced at least 20 minutes before sunset until approximately 1.5 hours after
sunset. A note of the time of activities recorded and general direction of flight was
also made. In addition, general bat activity on the Damhead Creek 2 site was noted
by recording the time, number and direction of bat passes in the general area, the
activity exhibited (foraging, feeding, fly past) along with identification.
13.5.50
The bat activity surveys conducted during 2006 did not show any evidence of use of
the derelict pump house as a roost site by bats. Small numbers of common pipistrelle
bats were however recorded commuting or foraging past the pump house. These
were generally observed travelling in a northerly direction from the existing Kingsnorth
Power Station (typically following the edge of the estuary).
13.5.51
As part of the development of Kingsnorth Business Park foraging bat surveys were
undertaken in August and September 2007 within Area 3 of the Damhead Creek 2
site by Middlemarch Consultants. These foraging surveys revealed that common
pipistrelles use some features for foraging. A maximum number of four common
pipistrelles have been recorded. The main activity concentrated around the water
bodies within the Damhead Creek 2 site. However, there was further activity in the,
woodland copse and scattered trees which are located outside of the footprint of
Damhead Creek 2.
13.5.52
In summary, based on the survey findings, it has been identified that there is a low
level of bat use in the Damhead Creek 2 site and as such it is considered that the
Damhead Creek 2 site is of local importance for bats. As such, potential impacts will
9
Mitchell-Jones A. J. (2004) Bat Mitigation Guidelines. English Nature, Peterborough
10 Mitchell-Jones, A. J. & McLeish, A. P. (1999). The Bat Workers’ Manual. JNCC, Peterborough.
June 2009
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ECOLOGY
need to be considered in light of legislation protecting these species in order to
ensure legal compliance.
Breeding Birds
13.5.53
All birds are protected under the Wildlife and Countryside Act 1981 (as amended)
from killing or disturbance during the breeding season (generally taken to be between
March and September inclusive). Furthermore, bird species set out in Schedule 1 to
the Wildlife and Countryside Act 1981 (as amended) (known as "Schedule 1
Species") have additional protection covering reckless disturbance.
13.5.54
A breeding bird survey was conducted by PAA following methodology based on the
breeding bird survey (BBS) methodology devised jointly by the British Trust for
Ornithology (BTO), the Royal Society for the Protection of Birds (RSPB) and the Joint
Nature Conservancy Council (JNCC)11
13.5.55
This methodology requires three visits to be made between late March and early July,
with each visit being over four weeks apart. On each of the survey visits the following
details were recorded:
Bird numbers, species, age and sex;
Habitats being used; and
Bird behaviour, e.g., singing, feeding, roosting, loafing, etc.
13.5.56
In keeping with the methodology, surveys began early in the morning and attempted
to avoid poor weather conditions. The Damhead Creek 2 site was surveyed using a
combination of transects and point observations.
This involved following a
predetermined route at a slow walking pace and longer periods of observations were
made at strategic points. Sightings were registered on a base map using standard
BTO codes. The survey area encompassed the Area 1 of the Damhead Creek 2 site
and the surrounding mitigation land owned by ScottishPower.
13.5.57
A total of 66 birds were recorded during the survey. Of these birds, 5 were confirmed
to be breeding, 25 were considered to be probably breeding and 25 were considered
to be possibly breeding. The remaining 11 species were considered to be nonbreeding species or breeding elsewhere. Of the 55 confirmed/probable/possible
breeding bird species recorded, 27 were of some conservation interest. No breeding
species included on the Medway Estuary and Marshes SPA citation were recorded
during the surveys. However, a number of species of conservation interest were
recorded during the survey. Of particular importance is the presence of the following
breeding species included on Schedule 1 of the Wildlife and Countryside Act 1981.
These included:
Barn Owl (Tyto alba) (including one pair close to the Damhead Creek 2 site);
Marsh Harrier (Circus aeruginosus); and
Cetti’s Warbler (Cettia cetti).
13.5.58
Additional surveys were undertaken for Areas 2 and 3 and the wider area by
Middlemarch Consultants as part of the Kingsnorth Business Park project proposed
by Goodman Developments Limited. The results were comparable in terms of the
breeding species assemblage recorded.
13.5.59
In summary, based on the size of the breeding bird assemblage, number of species of
conservation interest and the presence of Schedule 1 species, it is considered that
the breeding bird assemblage of the area encompassing the Damhead Creek 2 site
11
Gilbert, G., Gibbons, D.W., and Evans, J. (1998). Bird Monitoring Methods—a manual of techniques for key UK species.
RSPB, Sandy.
June 2009
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ECOLOGY
and adjacent land is of County importance. In addition potential impacts will need to
consider the legislation protecting breeding birds to ensure legal compliance.
Spring Passage Migratory Birds
13.5.60
Two spring passage migrant bird surveys were conducted in March and April 2007 by
PAA. The survey was timed to coincide with the main spring migration of waders
(with most spring passage migrants arriving between end March and May). The
purpose of the survey was to identify if the Damhead Creek 2 site supported
important populations of migrant waterbirds whilst on passage.
13.5.61
No passage migrants were recorded during the migrant bird surveys. As such the
Damhead Creek 2 area is considered to be of less than neighbourhood importance
for migratory birds and as such is not considered further in this assessment.
Winter Birds
13.5.62
A considerable amount of information has been published reviewing winter water bird
use of the intertidal areas of Damhead Creek. This includes a number of targeted
surveys and detailed reviews of Wetland Bird Survey (WeBS) Data. The findings of
these surveys are not repeated here however additional winter bird surveys (which
are available in Appendix G) were undertaken of both the Damhead Creek intertidal
habitats (part of the Medway Estuary and Marshes SPA/Ramsar/SSSI) and Areas 1
and 3. These were undertaken by PAA. The purpose of the surveys was to identify
the importance of the areas with respect to wintering waterbirds in particular those
which are a citation feature of the Medway Estuary and Marshes SPA/Ramsar/SSSI.
13.5.63
Additional surveys were undertaken to between October 2008 and March 2009. The
survey methods were based on those outlined for low and high tide estuarine bird
surveys in Gilbert et al (1998)12. Techniques used to estimate numbers followed
those given in Bibby et al13.2000). Two surveys were conducted each month to
coincide with periods of low and high water: The survey area was divided into 50m
grid square compartments. The low water bird surveys were undertaken for a
continuous 4 hour period, 2 hours prior/post low tide. The numbers and species of all
waterfowl present along the length of the survey area were recorded across the full
extent of visible intertidal habitat within the appropriate 50 m compartment on a map
of suitable scale to illustrate spatial distributions. The high water survey was
undertaken for a continuous 4 hour period 2 hours prior/post to high tide within
foreshore areas and the terrestrial near shore study area. As with the low tide survey
the numbers and species of all waterfowl present along the length of the survey area
were recorded on a map of suitable scale to illustrate spatial distributions (Appendix
G.12, Figures 1 to 14).
13.5.64
All surveys avoided periods of reduced visibility and the timing of surveys were varied
to incorporate different times of day and different levels of tides (Spring and Neap) in
order to reduce potential biases. Weather conditions, the conditions of the estuary
and marshes (e.g. wet flashes) and tide state on the survey day were recorded
together with details of any significant disturbance events.
13.5.65
Tide tables were used to confirm start and end times of the above counts. A suitable
vantage point was chosen and all waterbird species counted. Landscape features
were used as markers to ensure that double counting of an area did not take place.
Suitable optical equipment (binoculars and telescopes) were used to observe bird
behaviour, numbers and species.
12 Gilbert et al.(1998) Bird Monitoring Methods: A manual of techniques for key species. RSPB/BTO/JNCC/WWT/ITE/The
Seabird Group RSPB/BTO, Sandy. Classmark:598.2ROY
13 Bibby, C.J. Burgess, N.D. Hill, D.A. & Mustoe, S.H. (2000). Bird Census Techniques: 2nd edition. Academic Press, London.
June 2009
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ECOLOGY
13.5.66
The findings of the surveys were in keeping with the findings of other surveys and
WeBS data reviews all of which have identified that the intertidal areas adjacent to the
Damhead Creek 2 site are used as a feeding area by a wide variety of wetland birds,
with some being present in significant numbers at times and including species listed
in the Medway Estuary and Marshes SPA/Ramsar citation.
13.5.67
The 2008/09 surveys identified 14 species of waterbirds regularly using the survey
area at high and/or low tide. These included black-tailed godwit coot curlew,
greenshank, lapwing, little egret, little grebe, mallard, redshank, shelduck, shoveler,
teal, tufted duck, wigeon
13.5.68
Table 13.4 summarises the 2008/09 waterbird winter survey results and presents the
peak monthly count for both low and high tide along with the winter peak and mean
count for each species recorded.
June 2009
Page 185
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TABLE 13.4: SUMMARY OF WATER BIRD SURVEYS WINTER 2008/09
November
December
LT
October
HT
LT
HT
LT
HT
LT
HT
LT
HT
LT
HT
LT
HT
LT
HT
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Men
Men
Lapwing
83
309
255
190
415
156
17
106
163
1
0
1
415
309
156
127
Coot
4
4
3
4
4
6
12
4
5
7
9
10
12
10
6
6
Teal
240
106
480
257
422
293
693
333
614
130
171
96
693
333
437
203
Tufted duck
13
18
5
18
5
1
5
17
8
13
9
8
13
18
8
13
Little egret
4
31
0
10
0
4
0
2
3
3
0
1
4
31
1
9
Spotted redshank
2
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
Redshank
117
32
38
37
19
15
17
6
10
28
16
24
117
37
36
24
Wigeon
403
284
276
104
111
68
300
20
50
55
33
66
403
284
196
100
Black tailed godwit
21
0
0
0
0
0
0
0
0
0
0
0
21
0
4
0
Shoveler
1
2
23
25
70
33
89
17
99
77
15
17
99
77
50
29
Little grebe
7
5
6
7
3
5
9
6
3
6
3
3
9
7
5
5
Curlew
4
4
3
4
5
3
6
5
7
5
4
4
7
5
5
4
Cormorant
3
1
2
1
5
5
7
66
0
0
0
2
7
66
3
13
Black-headed gull
8
2
16
0
9
8
10
3
23
0
1
10
23
10
11
4
Grey plover
1
0
0
2
0
1
0
1
0
0
0
0
1
2
0
1
Mallard
42
24
27
14
20
5
6
22
11
5
2
4
42
24
18
12
Heron
1
0
0
1
1
0
0
0
3
0
0
0
3
1
1
0
Greenshank
1
15
0
3
0
1
0
0
0
0
0
1
1
15
0
3
Mute swan
0
3
0
0
0
0
0
0
0
0
0
0
0
3
0
1
Kingfisher
0
3
0
0
2
0
1
0
0
0
0
0
2
3
1
1
Snipe
0
1
0
6
0
0
1
1
1
0
1
1
1
6
1
2
Turnstone
0
1
0
0
0
0
0
1
0
0
0
0
0
1
0
0
Moorhen
0
1
1
3
1
0
0
0
0
0
0
2
1
3
0
1
Oystercatcher
0
0
3
1
3
1
3
1
3
3
5
3
5
3
3
2
Species
June 2009
Page 186
January
February
March
Total0
SECTION 13
ECOLOGY
October
November
December
January
February
March
Total0
LT
HT
LT
HT
LT
HT
LT
HT
LT
HT
LT
HT
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Max
Great crested grebe
Great black-backed
gull
0
0
1
1
1
2
0
0
0
0
0
0
0
1
0
1
0
14
1
Common gull
0
0
12
0
3
2
3
0
Ringed plover
0
0
1
0
0
0
2
Shelduck
0
0
3
0
6
2
14
Herring gull
0
0
2
0
1
1
Brent goose
0
0
0
0
0
Avocet
0
0
0
0
Gadwall
0
0
0
Dunlin
0
0
Pochard
Red-breasted
Merganser
0
0
Species
June 2009
Max
LT
Max
HT
Max
0
4
1
4
0
0
0
1
14
2
0
0
0
12
2
3
0
0
0
0
0
0
2
0
1
0
0
5
3
4
6
14
6
5
2
0
0
3
0
0
0
3
1
1
0
4
0
0
0
3
0
0
0
4
0
1
2
0
6
0
0
0
0
0
6
0
1
0
0
0
0
12
0
0
2
0
1
12
2
2
1
0
0
0
0
0
32
0
0
0
0
0
32
0
5
0
0
0
0
0
0
1
0
0
0
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
10
0
10
0
2
Page 187
LT
Men
HT
Men
1
0
3
SECTION 13
ECOLOGY
13.5.69
No large aggregations of waterbirds were recorded in Areas 1 or 3 (Area 2 is not
considered suitable for waterbird species) during the surveys. The majority of species
recorded occurred in low densities and the patterns of distribution for these species
was largely even across the survey area during both low and high tide. Where larger
numbers of birds were recorded there appeared to be some favouring of location
within the survey area. The spatial distributions for the following waterfowl species
(Appendix G12) indicate that, shoveler (Figures 11a-11d), teal (Figures 12a-12d) and
wigeon (Figures 14a-14d) were predominantly located in the north eastern areas of
the survey area both at low and at high tide. These three species of duck share
similar feeding preferences and it is reasonable to assume that the sections of the
survey area where they were observed in greatest densities correspond to favourable
feeding areas. The two most abundant wading birds recorded (lapwing and
redshank) were also noted to occur in more specific locations. Figures 5a -5d
illustrate that lapwing favoured the north eastern areas of the survey area. Figures 9a
and 9b illustrate that redshank were largely evenly distributed throughout the estuary
at low tide however Figures 5c and 5d illustrate that at periods of high water redshank
favoured the eastern shoreline of Damhead creek near to Kingsnorth.
13.5.70
The surveys have indicated that the footprint areas and hinterlands of the proposed
development are only used by small numbers of waterbirds and do not support
important high tide roosts. However it is considered that development activities in the
area could result in indirect effects. Due to the association with this designated site
the waterbird population is considered to be of International importance and impacts
to this VER are considered in relation to the Medway and Estuary Marshes
SPA/Ramsar/SSSI.
Reptiles
13.5.71
The Wildlife and Countryside Act 1981 (as amended) protects grass snakes (Natrix
natrix), slow worms, adders (Vipera berus) and common lizards (Lacerta vivipara)
making it an offence to deliberately or intentionally kill, injure, sell or trade these
species. Other UK reptile species namely smooth snakes (Coronella austriaca) and
sand lizards (Lacerta agilis) have additional protection under the Wildlife and
Countryside Act 1981, and the Habitat Regulations 1994.
13.5.72
The desk study completed by PAA identified a total of four records for two reptile
species within the 2 km search area, these being common lizard and slow worm.
13.5.73
Further reptile surveys of Area 1 (including the WCA) were undertaken in 2006 and
2007. Surveys in Area 2 were undertaken in 2007. A total of eight survey visits were
conducted in Area 1 (each year), however, only two visits were conducted Area 2 due
to limited access permissions during September 2007. In addition, Area 3 was
surveyed for the Kingsnorth Business Park project proposed by Goodman
Developments Limited by Middlemarch Consultants on five occasions between April
and June 2007.
13.5.74
The surveys entailed the placement of artificial refugia (50 cm x 50 cm roofing felt
pieces) to identify the presence, species and numbers of reptiles in each of the areas
of Damhead Creek 2.
13.5.75
The maximum count in any one survey of Area 1 (including the WCA) was 19
common lizards, 14 slow-worms and a single record of a grass snake. Juveniles of
common lizard and slow worm were recorded, along with a gravid female common
lizard, indicating that breeding habitat was present within or in close proximity to the
Damhead Creek 2 site. The majority of the records were taken from the grassy bank
in the WCA to the west of the ditch which provided the most suitable habitat for
reptiles. In the north-west of Area 1 one slow worm was recorded.
13.5.76
No reptiles were recorded in Area 2.
June 2009
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ECOLOGY
13.5.77
Much of Area 3 is considered to be unsuitable for reptiles and the surveys undertaken
here for the Kingsnorth Business Park project also encompassed a wider area than
the footprint of Damhead Creek 2. Area 3 (and its surroundings) was found to
support low populations of common lizards, slow worms and grass snakes.
13.5.78
In summary, within the footprint of the Damhead Creek 2 site, Area 1 is of greatest
importance to reptiles principally due to the habitat suitability and proximity to the
WCA. The remaining areas are considered to be of much lower importance for
reptiles based on the findings on the reptile surveys and existing habitat conditions.
Based on the survey results across the Damhead Creek 2 site the reptile population is
considered to be of district importance and in addition potential impacts will need to
consider the legislation protecting these species to ensure legal compliance.
Amphibians
13.5.79
The great crested newt is protected under the Wildlife and Countryside Act 1981 (as
amended), and under the Conservation (Natural Habitats &c) Regulations 1994. It is
illegal to deliberately capture, injure or kill a great crested newt, to intentionally or
recklessly disturb great crested newts, or to deliberately take or destroy the eggs of
great crested newts. It is also illegal to damage, destroy or intentionally or recklessly
obstruct access to a breeding or resting place used by a great crested newt. All life
stages of great crested newts are afforded the same level of protection.
13.5.80
The desk study completed by PAA identified three records for great crested newt
(Triturus cristatus) two of which stemmed from the neighbouring existing Kingsnorth
Power Station. In addition two records for smooth newt (Triturus vulgaris) were
identified, one of which was also from the existing Kingsnorth Power Station.
13.5.81
Further surveys undertaken at and in the vicinity of Area 1 of the Damhead Creek site
(500 m) revealed the presence of great crested newts in the adjacent water bodies
(further information is provided in Appendix G). A translocation was undertaken
during 1998 as part of the development of the existing Damhead Creek CCGT Power
Station, during which the species were moved to the WCA. Monitoring surveys
undertaken during 2003, 2005 and 2007 have confirmed the presence of this species
within 500 m of the Damhead Creek 2 site.
13.5.82
In addition, a large waterbody outside Area 2 and the three water bodies within Area 3
have been surveyed as part of the Kingsnorth Business Park project by Middlemarch
Consultants. None of these water bodies were found to support great crested newts
or any other amphibians. All these water bodies are connected to the estuary making
the water highly saline and therefore unsuitable for amphibians. Furthermore, the
temporary pond in Area 2 is considered unsuitable for great crested newts given the
varying conditions of water, fragmented location and lack of suitable habitat for
breeding newts. The pond to the north of this Area (beyond the site boundary) has
been surveyed on a number of occasions and no great crested newts have been
recorded. Sporadic records of smooth newt have occurred but the presence of fish
suggests that this pond is not suitable for amphibians.
13.5.83
In summary, the survey findings identify that the WCA adjacent to Area 1 supports
great crested newts. Furthermore, the grassland habitats within Area 1 potentially
provide foraging habitat for great crested newts. As such the great crested newt
population is considered to be of local/district importance and in addition potential
impacts will need to consider the legislation protecting these species to ensure legal
compliance.
Terrestrial Invertebrates
13.5.84
A range of invertebrate records were identified during the desk study completed by
PAA within the 2 km search area. These included records of 13 species listed within
June 2009
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SECTION 13
ECOLOGY
Invertebrate Red Data Books 1 2 as endangered, vulnerable or rare. One species is a
UK Biodiversity Action Plan priority species (Picture-winged fly Dorycera graminum).
13.5.85
Observational and targeted surveys within Area 1, Area 2 and the WCA recorded a
range of common and widespread species. Several local and scarce species were
also present. The grassland was used by common odonata and lepidoptera.
Butterflies including, small heath, small copper, common blue along with common
darter dragonflies were observed in the amenity grassland at the road verge, along
the north western boundary of Area 1. Overall, more species were recorded within
the WCA than both Areas 1 and 2.
13.5.86
In addition, as part of the Kingsnorth Business Park project, a detailed terrestrial
invertebrate survey was undertaken in 2006 by Middlemarch Consultants. This
included some of Area 3, although it should be noted this area was a component of
very much larger survey area (for application MC/2008/0370). The surveys
identified 11 species of conservation interest of which two were Red Data Book
species and 9 nationally scarce species. A total of 25 species of conservation interest
were recorded in the wider study area of which four were Red Data Book species and
21 nationally scarce species. One of the Red Data Book species Anisodactylus
poeciloides is also a priority species in the Kent Biodiversity Action Plan and this
species has been recorded within the boundary of Area 3 within the Damhead Creek
2 site.
13.5.87
In summary, the invertebrate fauna across the Damhead Creek 2 site and, more
significantly, the wider area, reflects the Damhead Creek 2 site’s coastal location in
north Kent, on the edge of the broader East Thames corridor. There are coastal
species, species typical of wetland habitats and ponds, and species typical of species
rich grassland and brownfield sites, as would be expected given the habitats present
and recent site origin. Based on the survey findings the terrestrial invertebrate
population is considered to be of local importance and as such is considered further in
this assessment.
Aquatic Invertebrates
13.5.88
Aquatic invertebrate surveys (included in Appendix G) were undertaken of the ditches
close to Area 1 and the ponds in the WCA by PAA. The water bodies were sampled
using the Environment Agency’s own standard method3.
13.5.89
Within Area 1, three ponds and two ditches were surveyed for their aquatic
invertebrate diversity. Two of the ponds supported reasonably diverse fauna and was
particularly good for odonata. The third pond was relatively species-poor, and it is
likely that this pond seasonally dries out. Several of the beetle species found here
are closely associated with marshy, muddy habitats.
13.5.90
In the ditches there was evidence of brackish influence with various brackish watertolerant species including; freshwater shrimp (Gammarus duebeni); water slater
(Asellus meridianus), blue-tailed damselfly (Ishura elegans) and Jenkins spire shell
(Potamopyrgus jenkinsi). One of the ditches (specific ditch not identified within the
invertebrate survey report) appeared to receive the greatest brackish influence, it was
closer to the estuary and included the ditch shrimp (Palaemontes varians), and this
species will only survive for short periods of time in freshwater. This ditch also
supported good populations of the introduced shrimp (Gammarus tigrinus), normally
only found in estuaries. The emerald damselfly (Lestes sponsa) was found on two
occasions. The vulnerable species scarce emerald damselfly (Lestes dryas) is known
to exist in the wider area; but larvae were not found during the survey.
1
Bratton, J.H. (ed.), (1991). British Red Data Books: 3. Invertebrates other than insects. JNCC, Peterborough.
2
Shirt, D.B. (ed.), (1987). British Red Data Books: 2. Insects. NCC, Peterborough
3
Environment Agency (1999). Procedures for collecting and analysing macroinvertebrate samples. The Environment Agency.
June 2009
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ECOLOGY
13.5.91
In addition, as part of the Kingsnorth Business Park project, water bodies A, B, and C
and the western ditch within Area 3 have been surveyed for aquatic invertebrates by
Middlemarch Consultants. Nine species have been found in total in waterbody A of
which only one species is of conservation concern: Berosus affinis. This species is
associated with silty ponds and drains and can tolerate brackish conditions.
13.5.92
Water bodies B and C were found to have nine species in total but no species of
conservation concern were found here.
13.5.93
The western ditch in the WCA sustained a total of 21 species of which 6 were of
conservation concern: Agabus conspersus, Hygrotus parallelogrammus, Haliplus
apicalis, Berosus affinis, Enochrus halophilus, Limnoxenus niger. All of the above
species are associated with brackish water. This ditch is located outside of the
13.5.94
In summary, the species found during the surveys on the Damhead Creek 2 site are
not protected under existing legislation and the aquatic invertebrate assemblage is
considered to be of local importance. As such, they are not considered further in this
assessment.
Assessment of Valued Ecological Receptors
13.5.95
As documented above each habitat, species or species assemblage recorded has
been assigned an ecological value according to the geographical scale at which it is
important in accordance with the IEEM guidelines. These are summarised in Table
13.5. Where sites have designations at different levels (International, National and
Regional/County/Local) the highest value has been assigned.
TABLE 13.5: SUMMARY OF VALUED ECOLOGICAL RECEPTORS
Site/Habitat/Species
Value
Evaluation Rationale
All European designated sites (as
presented in Table 13.3)
International
Sites designated under European directives for
internationally important features.
All Nationally designated sites (as
presented in Table 13.3)
National
Sites designated under UK legislation for
nationally important features.
Water bodies including; ponds ditches,
saline/brackish lagoons and associated
marginal habitats
County
Common in a local context but less so on a wider
scale. Supports protected and/or species of
conservation interest.
Badger
Local
Low levels of use across the Damhead Creek 2
site and no setts present.
Water vole
Local
Abundant in the area. Legal protection afforded
to the species and their habitats will require
consideration.
Bats
Local
Low levels of use across the Damhead Creek 2
site and no roosts present. Legal protection
afforded to the species will require consideration.
Breeding Birds
County
A number of breeding species of conservation
concern present the assemblage comprises an
area wider than the Damhead Creek 2 site. All
breeding birds receive protection under the
Wildlife & Countryside Act 1981 (as amended).
Intertidal Birds
International
Component feature of the European designated
site this receptor is considered in conjunction with
the Medway Estuary SPA/Ramsar.
Reptiles
District
Common lizard and slow worm are present in
relatively high numbers. Legal protection
afforded to the species will require consideration.
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Site/Habitat/Species
Value
Evaluation Rationale
Amphibians
Local
Small breeding great crested newt population
within 500m. Legal protection afforded to the
species and their habitats will require
consideration.
Local
Species typical of the region and habitats
present.
Local
Species typical of the region and habitats
present.
13.5.96
The following habitats are not considered to be valued ecological receptors and thus
are not considered further as part of this assessment: semi-improved grassland;
scattered scrub; dense scrub; ruderal; sparse vegetated ground; and, hard
standing/gravel.
13.6
Predicted Changes in Baseline
13.6.1
The EIA assessment baseline entails the following known changes to the existing
situation within the phases of construction, operation and decommissioning of
Damhead Creek 2.
13.6.2
Construction of Damhead Creek 2 is expected to commence as early as 2013 and
last for 3 years. Subsequently Damhead Creek 2 will be operational for a period of 35
years.
13.6.3
The main features of Damhead Creek 2 will comprise a new power plant, a substation
and areas of semi-permanent hard standing for laydown which will be reserved for
any future carbon capture storage requirements.
13.6.4
Significant changes in baseline conditions for the VERs during the period between the
present time and commencement of construction are considered unlikely.
13.7
Potential Impacts
13.7.1
The methodology used to identify and characterise potential impacts, and to assess
the significance of these impacts is described in the methodology details above. In
summary, this section identifies the likely effects on Valued Ecological receptors
(VER) of Damhead Creek 2 during construction, operation and decommissioning and
characterises the potential ecological impacts that are likely to arise. In this
assessment the following parameters will be taken into consideration:
positive/negative effect; magnitude; extent; duration; reversibility; and,
timing/frequency.
13.7.2
The impacts are assessed on the basis of the details of construction, operation and
eventual decommissioning of Damhead Creek 2 as outlined in Section 5. For the
purpose of this assessment a precautionary approach has been taken which assumes
the effects of decommissioning Damhead Creek 2 are considered to be likely to result
in similar types of impacts as per those of the construction and as such are unlikely to
be of greater significance.
13.7.3
The assessment focuses on likely impacts to identified Valued Ecological Receptors
(VER), as summarised above in Table 13.5. Significance is assessed as being either:
very high; moderate or low.
13.7.4
The potential impacts of Damhead Creek 2 to the VERs are discussed below.
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Construction Impacts
Expected Construction Impacts
13.7.5
The construction works associated with Damhead Creek 2 could result in the
following impacts to VERs:
Permanent and temporary habitat loss;
Direct mortality during site clearance and construction;
Direct and indirect disturbance from construction activities including visual, noise,
dust and lighting;
Degradation of adjacent habitats of conservation importance; and
Pollution caused by use of hazardous materials and release of waste materials.
13.7.6
The effect of these impacts on the various Designated Sites, Habitats and Species is
discussed below.
Designated Sites
13.7.7
No direct loss of habitat to any designated sites will occur as a result of Damhead
Creek 2. It is considered that, with the exception of the Medway Estuary and
Marshes SSSI/SPA/Ramsar (as discussed below), the designated sites are located
sufficiently far away from the Damhead Creek 2 site to be unaffected by any potential
negative impacts from disturbance or pollution during the construction period. It is
considered that the magnitude of these impacts will result in no change and are
therefore are assessed as being not significant.
13.7.8
The Medway Estuary and Marshes is located adjacent to the Damhead Creek site.
Based on the findings of the surveys undertaken for waterbirds by both PAA and
Middlemarch Consultants it is apparent that the proposed development Areas 1 and 2
within the Damhead Creek 2 site are not utilised by waterbird species including those
cited on the European Site designations. As such the loss of these habitats is
considered to have no effect upon the ornithological features associated with the
Medway Estuary and Marshes. Furthermore, Areas 1 and 2 are considered to be
sufficiently distant and naturally screened from the estuary and foreshore to reduce
any disturbance effects in these areas to a negligible magnitude and not significant.
13.7.9
However, the southern half of Area 3 is located almost adjacent to the Medway
Estuary and Marshes designated site. Surveys have identified that the foreshore in
Area 3 and the adjacent intertidal areas are of importance to the citation features of
the Medway and Estuary Marshes.
13.7.10
There is considerable debate into the effects of disturbance on birds and bird
populations4 5. Assessments of whether disturbance has a negative effect on
populations often relies on monitoring behavioural responses to disturbance, such as
the closest distance to which a disturbance source is approached or the time for
animals to return after disturbance has ceased, and it is often assumed that a larger
behavioural response indicates a greater susceptibility to disturbance6.
4 Hockin, D., Ounsted, M., Gorman, M., Hill, D., Keller, V. & Barker, M.A. 1992. Examination of the effects of disturbance on
birds with reference to its importance in ecological assessments. J. Environ. Manage. 36: 253–286.
5 Hill, D., Hockin, D., Price, D., Tucker, G., Morris, R. & Treweek, J. 1997. Bird disturbance: improving the quality and utility of
disturbance research. J. Appl. Ecol. 34: 275–288
6 Gill, J.A., Sutherland, W.J. & Watkinson, A.R. 1996. A method to quantify the effects of human disturbance on animal
populations. J Appl Ecol 33: 786–792.
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13.7.11
The issues that disturbance can cause waterbirds in intertidal zones is due to the tidal
restrictions on their foraging. Disturbance of waders and waterfowl by human
activities during their feeding periods might have negative effects on their ability to
acquire sufficient food. This is particularly important in the winter and migratory
periods as energy demands are particularly high. Disturbance can cause a reduction
in food intake in several ways: the presence of disturbance leads to increased
vigilance by foraging waders and to a decrease in the proportion of time devoted to
feeding, the birds may stop foraging altogether and they may leave the foraging site
and relocate to areas of lower foraging yield or areas subject to greater foraging
competition. In addition to this reduction in food intake, energy expenditure can be
increased by avoidance behaviour, particularly if the birds fly away. The combination
of these effects may produce serious deficits in the daily energy budget of the
disturbed birds, or necessitate extra foraging7.
13.7.12
In assessing the potential construction impacts the nature of the disturbance is an
important consideration. There are a number of types of disturbance. These include:
visual; noise and vibration; dust; and, lighting. Research suggests that the magnitude
of these effects to birds can vary considerably.
13.7.13
A recent long term study of the effects of construction disturbance at Cardiff Bay
indicated that the densities of five species (Teal, Oystercatcher, Dunlin, Curlew, and
Redshank) were significantly reduced adjacent to construction work and that those of
Shelduck tended to be also. Construction work also reduced the feeding activity of
Oystercatcher, Dunlin, and Redshank 8. The study suggested that whilst these
species may have become habituated to more regular and predictable disturbances,
they did not become habituated to the irregular nature and noise of activities
associated with construction work. As a result they seemed to avoid the mudflats
adjacent to any such work for its duration. Only densities of Mallard, a species well
used to disturbance, were not obviously affected by construction work.
13.7.14
The study did acknowledge that evaluating the overall effects of these impacts is
difficult to define given the influences of other factors. Therefore, the effects of the
construction disturbance did not conclusively identify an impact at a population level.
However, the evidence did suggest that the construction disturbance might have been
a contributing factor for some species.
13.7.15
It is important to note that the proposed development in some areas of the Damhead
Creek 2 site is in few ways comparable to the scale of the Cardiff Bay development.
As such, the findings of these studies can only go so far to aid in identifying the
potential effect of disturbance resulting from the proposed Development considered in
this assessment.
13.7.16
Research suggests that the greatest impacts to birds are those arising from visual
disturbance. Furthermore, there is evidence to suggest that people are one of the
greatest forms of visual disturbance. As such, when birds see a person or people
silhouetted against the skyline, the disturbance effect can be significant.
13.7.17
In considering the effect of visual disturbance in relation to the construction activities,
Area 3 will be used for laydown which will entail site clearance and the installation of a
permanent/semi permanent substrate. As such, Area 3 within the Damhead Creek 2
site will be used regularly throughout the construction period by vehicles and site
workers. Subject to detailed design, the intention is for the laydown area to be kept
as far north of the estuary as is feasible to reduce the potential disturbance effects to
features of the Medway Estuary and Marshes SPA/Ramsar/SSSI. Furthermore, the
7
Fitzpatrick, S. & Bouchez, B. 1998. Effects of recreational disturbance on the foraging behaviour of waders on a rocky beach.
Bird Study 45: 157–171.
8
Burton, N.H.K., Rehfisch, M.M. & Clark, N.A. 2002. Impacts of disturbance from construction work on the densities and
feeding behaviour of waterbirds using the intertidal mudflats of Cardiff Bay, UK. Environ Manage 30 865–871.
June 2009
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ECOLOGY
seawall and several spoil piles provide some visual screening of Area 3 to the Estuary
and greatest aggregations of birds were noted in the north east sections of Damhead
creek, furthest from the proposed development areas.
13.7.18
The other key disturbance effect that could occur during the construction phase is
noise. Full potential noise impacts are assessed within Section 11 of this ES.
However, the expected noise disturbance activity in Area 3 will not be of a particularly
disturbing nature in comparison to piling for example.
13.7.19
In summary, whilst the activities in Area 3 are likely to be of least disturbance to
waterbirds compared to those in Areas 1 and 2 it is considered that the disturbance
effects of the construction works are of medium magnitude and significant at an
International level. In addition, the potential effects of pollution and degradation to the
Medway Estuary and Marshes during the construction process are also considered to
be of medium magnitude and significant at an International level.
Habitats
Water Bodies
13.7.20
Based on the footprint of the proposed development there will be no temporary or
permanent loss of water bodies in Areas 1 and 2 as a result of construction.
However, there is potential for indirect effects to water bodies in Area 1. Potential
impacts would be associated with habitat degradation and pollution. This adverse
impact based on the habitat feature alone and not to any associated fauna, is
considered to be of medium magnitude and significant at a county level.
13.7.21
The construction is likely to result in the permanent loss of some water bodies within
Area 3 (subject to detailed design). The full extent of permanent loss is, at present,
not quantifiable but will be minimised as much as is possible and fully identified at the
detailed design stage. For the purpose of this assessment it has been assumed that
the interconnected waterbodies; labelled as P3 in Figure 10.2 of the Kingsnorth
Business Park ES and included as Appendix G of this document, will be removed
during the construction process. This adverse impact based on the habitat feature
alone and not to any associated fauna, is considered to be of medium magnitude and
significant at a county level.
Species
Badgers
13.7.22
No badger setts are located within 30 m of the Damhead Creek 2 site. However, it is
likely that a sett is located in the local area and there is limited use of the Damhead
Creek 2 site by badgers based on the survey findings. The potential effects to
badgers resulting from the construction include permanent and temporary loss of
foraging habitat, habitat fragmentation, disturbance and increased risk of mortality via
site activities (e.g., traffic and falling into trenches).
13.7.23
Based on the relatively small area of permanent foraging habitat loss (~6 ha) and
substantial quantity of alternative areas in the immediate vicinity of the Damhead
Creek 2 site the magnitude of habitat loss is considered to be negligible and as such
not significant.
13.7.24
Based on the survey findings and the design layout it is considered that Damhead
Creek 2 is unlikely to comprise a barrier effect to commuting badgers based on the
location of the development in relation to habitat corridor features and this potential
impact is considered to be negligible and as such not significant.
13.7.25
Disturbance to badgers during the construction activities include visual, noise, dust
and lighting. These potential impacts would result in a negative effect of low
magnitude and significant at a local level.
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13.7.26
Mortality of any badgers as a result of the construction activities would be a negative
effect of low magnitude (with the potential to escalate if a number of badgers were
affected) and significant at a local level.
Water Voles
13.7.27
Based on the surveys previously undertaken, water voles are present in many of the
water bodies within and around the Damhead Creek 2 site, although the water bodies
in which they are present are not specified within the survey reports. The potential
effects to water voles arising during the construction include permanent and
temporary habitat loss, habitat fragmentation, disturbance and increased risk of
mortality via site clearance activities.
13.7.28
The permanent loss of selected water bodies within Area 3 would result in permanent
loss of water vole habitat equating to a negative effect of medium magnitude and
significant at a local level.
13.7.29
The water vole population in Area 1 could be subject to disturbance effects such as
visual, noise and dust associated with the construction processes. This potential
impact would result in a negative effect of low magnitude and significant at a local
level.
13.7.30
Due to the transient nature of water voles and known populations in the local area the
potential effects of habitat fragmentation are considered as being of medium/high
magnitude and on the basis the effect could extend beyond the Damhead Creek 2
site and the potential impact is considered to be significant at a district level.
13.7.31
Disturbance to water voles during the construction activities include visual, noise, dust
and lighting. These potential impacts would result in a negative effect of low
13.7.32
Mortality of any water voles as a result of the construction activities would be a
negative effect of low magnitude (with the potential to escalate if a number of water
voles were affected) and significant at a local level.
13.7.33
Due to the statutory protection afforded to water voles all of the impacts identified
above arising from the construction processes would potentially result in an offence
under the Wildlife and Countryside Act 1981.
Accordingly mitigation and
compensation measures, as detailed in Section 13.8, will be necessary to comply with
the legislative requirements.
Bats
13.7.34
Potential impacts to bats are associated with indirect effects to the small number
present commuting and foraging across the Damhead Creek 2 site. Potential
negative effects are likely to be associated with permanent habitat loss of some water
bodies in Area 3 and increased levels of lighting during construction.
13.7.35
The permanent loss of selected water bodies within Area 3 would result in permanent
loss of bat foraging habitat and likely commuting corridor features equating to a
negative effect of medium magnitude and significant at a local level.
13.7.36
The use of artificial lighting during construction will be temporary. Some bat species
use lighting as a positive effect for foraging (due to the lights attracting moths and
other flying insects) whilst the effects on other species can be negative from
disturbance and increased risk of predation. Lighting can be particularly harmful
along important corridor routes such as river corridors, as lit areas can effectively
cause a barrier through which bats will not pass. Accordingly the effects of this
impact are likely to be of low magnitude and as such significant at a local level.
Birds (not associated with the Medway Estuary and Marshes SPA/Ramsar/SSSI)
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13.7.37
The potential effects to breeding birds resulting from the construction include
permanent and temporary loss of breeding and foraging habitat, disturbance, and
increased risk of mortality via site clearance activities.
13.7.38
Area 1 will be permanently lost as a result of the Damhead Creek 2 development. At
present, this area provides breeding bird habitat also in addition to foraging habitat for
barn owl and, to a lesser extent, marsh harrier (more likely to forage in the
estuarine/saltmarsh areas). As such this effect is considered to be of high magnitude
and significant at a County level.
13.7.39
Disturbance to breeding birds during the construction activities include visual,
noise/vibration, dust and lighting. These potential impacts would result in a negative
effect of medium magnitude and significant at a County level.
13.7.40
Mortality of any birds as a result of the construction activities would be a negative
effect of at least low magnitude (species dependent being higher for rarer species)
and significant at a County level.
13.7.41
Due to the statutory protection afforded to breeding birds all of the impacts identified
above arising from the construction processes would potentially result in an offence
under the Wildlife and Countryside Act 1981.
Reptiles
13.7.42
The potential effects to reptiles resulting from the construction include permanent and
temporary loss of foraging habitat, habitat fragmentation, disturbance and increased
risk of mortality via site clearance activities.
13.7.43
Area 1 will be permanently lost as a result of the Damhead Creek 2 development. At
present, this area provides foraging and hibernating habitat to the reptile populations
identified during the surveys. The small numbers of reptiles recorded in Area 3 will
also be subject to some permanent loss of habitat. The WCA will be retained and no
direct impacts are predicted for the WCA. The WCA was established to provide,
amongst other features, habitat compensation for reptiles and it is considered that the
WCA still fulfils this purpose although at present based on the current habitat
management it is probably not suitable to accommodate an increasing population of
reptiles. As such this effect is considered to be of medium magnitude and significant
at a district level. Further details of how this issue could be addressed are provided in
Section 13.8.
13.7.44
Based on survey findings and the design layout it is considered that the location of
Damhead Creek 2 in relation to habitat corridor is such that it is unlikely to comprise a
barrier effect to commuting reptiles. Therefore this potential impact is considered to
be negligible and as such not significant.
13.7.45
Disturbance to reptiles during the construction activities include visual, noise/vibration,
dust and lighting. These potential impacts would result in a negative effect of low
magnitude and significant at a district level.
13.7.46
Mortality of any reptiles as a result of the construction activities would be a negative
effect of low magnitude (with the potential to escalate if a number of reptiles were
affected) and significant at a district level.
13.7.47
Due to the statutory protection afforded to reptiles all of the impacts identified above
arising from the construction processes would potentially result in an offence under
the Wildlife and Countryside Act 1981. Accordingly mitigation and compensation
measures, as detailed in Section 13.8, will be necessary to comply with the legislative
requirements.
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Amphibians
13.7.48
The potential effects to amphibians, principally great crested newt, resulting from the
construction include permanent and temporary loss of foraging habitat, habitat
fragmentation, disturbance, pollution and increased risk of mortality via site clearance
activities.
13.7.49
Area 1 is the only area within the footprint of the Damhead Creek 2 site where great
crested newts are known to occur. This area will be permanently lost as a result of
the Damhead Creek 2 development. In addition, this area provides potential foraging
and hibernating habitat to the great crested newt populations identified during the
surveys. However, the WCA will be retained and no direct impacts to amphibians are
predicted for the WCA. The WCA was established to provide, amongst other
features, habitat compensation for great crested newts and it is considered that given
the small population of great crested newts present the WCA still fulfils this purpose.
As such the effect of permanent habitat loss to great crested newts is considered to
be negligible and not significant.
13.7.50
Based on survey findings and the design layout it is considered that Damhead Creek
2 is unlikely to comprise a barrier effect to great crested newts and this potential
13.7.51
Disturbance to great crested newts during the construction activities include visual,
noise/vibration, dust and lighting. These potential impacts would result in a negative
effect of low magnitude and significant at a local level.
13.7.52
Mortality of any great crested newts as a result of the construction activities would be
a negative effect of low magnitude (with the potential to escalate if a number of great
crested newts were affected) and significant at a local level.
13.7.53
Due to the statutory protection afforded to great crested newts all of the impacts
identified above arising from the construction processes would potentially result in an
offence under the Habitats Regulations 1994.
13.7.54
The potential effects to terrestrial invertebrates, resulting from the construction include
permanent and temporary loss of habitat, habitat fragmentation, disturbance and
mortality.
13.7.55
Both Areas 1 and 3 were identified as supporting terrestrial invertebrates of
conservation interest. Both of these areas will be subject to permanent habitat loss
as a result of Damhead Creek 2. As with the reptile and amphibians some of this loss
has already been compensated for in the creation of the WCA. On this basis the
permanent loss of habitat to terrestrial invertebrates is considered to be of low
13.7.56
Based on survey findings and the design layout it is considered that in light of the
location of the development in relation to habitat corridor features Damhead Creek 2
is unlikely to comprise a barrier effect to terrestrial invertebrates and this potential
13.7.57
Disturbance to terrestrial invertebrates during the construction activities include visual,
noise, dust and lighting. These potential impacts would result in a negative effect of
low magnitude and significant at a local level.
13.7.58
Mortality of any terrestrial invertebrates as a result of the construction activities would
be a negative effect of low magnitude (with the potential to escalate if a number of
invertebrates were affected) and significant at a local level.
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13.7.59
The potential effects to aquatic invertebrates, resulting from the construction include
permanent and temporary loss of habitat, habitat fragmentation, disturbance and
mortality.
13.7.60
Water bodies in the WCA will be retained under the Damhead Creek 2 development
and as such any impacts will be indirect. Area 3 was identified as supporting only one
aquatic invertebrate of conservation interest. As this area will be subject to
permanent habitat loss as a result of Damhead Creek 2 development the impact is
considered to be of medium magnitude and significant at a local level.
13.7.61
Based on survey findings and the design layout it is considered that Damhead Creek
2 is unlikely to comprise a barrier effect to aquatic invertebrates and this potential
13.7.62
Disturbance to aquatic invertebrates during the construction activities include
noise/vibration dust and lighting. These potential impacts would result in a negative
effect of low magnitude and significant at a local level.
13.7.63
Mortality of any aquatic invertebrates as a result of the construction activities would
be a negative effect of low magnitude (with the potential to escalate if a number of
invertebrates were affected) and significant at a local level.
Summary
13.7.64
A summary of the potential unmitigated impacts from construction, described above,
are provided in Table 13.6.
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TABLE 13.6: SUMMARY OF UNMITIGATED CONSTRUCTION IMPACTS
VER
Value
Type of Impact
Medway Estuary and
Marshes SPA/Ramsar/SSSI
(including bird assemblage)
International
Disturbance
All other European
Designated Sites
International
Disturbance
Magnitude and Extent of Impact
Medium – Indirect effects from
construction activities could disturb
and displace water birds in the
estuary.
Negligible – Sites are sufficiently
distant from the Damhead Creek 2
site and remain unaffected.
Confidence,
Duration and
Reversibility
Possible,
Short term,
Significance of
Impact
Significant
International level
Reversible
Near certain,
Not Significant
Short term,
Reversible
All other Nationally
Designated sites
Water bodies including:
ponds ditches,
saline/brackish lagoons and
National
County
Disturbance
Habitat loss
Habitat degradation/pollution
Near certain,
Medium – Selected water bodies in
Area 3 permanently lost during the
construction phase..
Near certain,
Medium – Indirect effects from
construction activities to water bodies
in Area 1.
Short term,
Reversible
Long term,
Page 200
Significant
County level
Irreversible
Possible,
Long term,
Reversible
June 2009
Not Significant
Significant
County level
SECTION 13
ECOLOGY
VER
Badger
Value
Type of Impact
Confidence,
Duration and
Reversibility
Local
Habitat loss
Negligible – No setts affected. Area
of permanent loss is of limited use to
badgers. Extensive alternative
habitats in the immediate area.
Near certain,
Negligible – Design layout should not
comprise a constraint to badger
movements in the local area.
Near certain,
Habitat fragmentation
Significance of
Impact
Not Significant
Long term,
Irreversible
Not Significant
Long term,
Irreversible
Disturbance
Increased mortality
Water Vole
Local
Habitat loss
Low – Limited activity on the
Damhead Creek 2 site and largely
nocturnal and therefore present
outside of construction working
hours.
Low – Potential for individuals to be
subject to road mortality from
increased presence of traffic.
Potential for individuals to fall into
excavation areas, trenches etc.
construction phase.
Possible,
Significant
Short term,
Local level
Reversible
Possible,
Significant
Short term,
Local level
Irreversible
Near certain,
Significant
Long term,
Local level
Irreversible
Disturbance
Low – Some potential for impacts to
Area 1.
Possible,
Significant
Short term,
Local level
irreversible
June 2009
Page 201
SECTION 13
ECOLOGY
VER
Value
Type of Impact
Confidence,
Duration and
Reversibility
High – Water voles are transient and
effects could extend beyond the
Possible,
Increased mortality
Bats
Local
Foraging habitat loss
Disturbance through increased
lighting
construction phase.
Low – Small numbers of bats
present, effects of lighting vary
depending on species.
Long term,
Significance of
Impact
Significant
District level
Irreversible
Possible,
Significant
Short term,
Local level
Irreversible
Near certain,
Significant
Long term,
Local level
Irreversible
Possible,
Significant
Short term,
Local level
Reversible
Breeding Birds
County
Habitat loss
High – Area 1 permanently lost
during the construction phase.
Near certain,
Long term,
Significant
County level
Irreversible
Disturbance
Medium – Some potential for impacts
to adjacent habitats.
Possible,
Short term,
Irreversible
June 2009
Page 202
Significant
County level
SECTION 13
ECOLOGY
VER
Value
Type of Impact
Increased mortality
Reptiles
District
Habitat loss
Disturbance
Medium – Permanent loss of habitats
in Areas 1 and 3. Some
compensation already undertaken
(WCA).
Low – Some potential for impacts
adjacent to Area 1 (WCA).
Confidence,
Duration and
Reversibility
Significance of
Impact
Possible,
Significant
Short term,
Local level
Irreversible
Near certain,
Long term,
Significant
District level
Irreversible
Possible,
Short term,
Significant
District level
Reversible
comprise a constraint to reptile
Possible,
Long term,
Significant
District level
Irreversible
Increased mortality
Amphibians
Local
Habitat loss
Negligible – Small population and
mitigation/compensation already
implemented for loss of habitat.
Possible,
Short term,
Page 203
District level
Irreversible
Near certain,
Long term,
Irreversible
June 2009
Significant
Not Significant
SECTION 13
ECOLOGY
VER
Value
Type of Impact
Confidence,
Duration and
Reversibility
comprise a constraint to amphibian
Near certain,
Disturbance
Significance of
Impact
Not Significant
Long term,
Irreversible
Possible,
Significant
Short term,
Local level
Reversible
Increased mortality
Local
Habitat loss
Low – Permanent loss of habitats in
Areas 1 and 3. Some compensation
already undertaken (WCA).
Possible,
Significant
Short term,
Local level
Irreversible
Near certain,
Significant
Long term,
Local level
Irreversible
Disturbance
comprise a constraint to terrestrial
invertebrate movements in the local
area.
Near certain,
Long term,
Irreversible
Possible,
Significant
Short term,
Local level
Reversible
June 2009
Page 204
Not Significant
SECTION 13
ECOLOGY
VER
Value
Type of Impact
Increased mortality
Low – Some limited potential for
impacts.
Confidence,
Duration and
Reversibility
Significance of
Impact
Possible,
Significant
Long term,
Local level
Irreversible
Local
Habitat loss
Medium– Permanent loss of habitats
in Area 3. Limited invertebrate
interest present.
Near certain,
Significant
Long term,
Local level
Irreversible
Disturbance
comprise a constraint to terrestrial
invertebrate movements in the local
area
Near certain,
Not Significant
Long term,
Irreversible
Possible,
Significant
Short term,
Local level
Reversible
Increased mortality
Low – Some limited potential for
impacts.
Possible,
Significant
Long term,
Local level
Irreversible
June 2009
Page 205
SECTION 13
ECOLOGY
Operational Impacts
Expected Operational Impacts
13.7.65
There are potential impacts on VERs that can result from the operation of Damhead
Creek 2. These potential impacts can include:
Air quality effects resulting from operational emissions (presented separately
below) including nitrogen deposition and acidification;
Water discharge into the Medway estuary;
Disturbance effects resulting from increased noise and vibration and light from
the operational processes; and
Water pollution from surface water drainage from roads, buildings and hard
standing areas. Further information on the impacts associated with water quality
is included in Section 14 of the ES.
Air Quality
13.7.66
Operation of Damhead Creek 2 may lead to changes in air quality at the nearby
European designated wildlife sites (Natura 2000 sites) and Sites of Special Scientific
Interest (SSSI). Full details of the changes in and modelling of air quality associated
with the operation of Damhead Creek 2 are provided in Section 10 of this ES.
13.7.67
Technical Guidance Note AQTAG 06 requires that consideration be given to
receptors within 10 km of emissions sources. There are a number of such sites within
10 km of the Damhead Creek 2 site that have European and National designations.
These are:
Medway Estuary and Marshes SPA/RAMSAR Site and SSSI (adjacent);
Dalham Farm SSSI (4 km north west);
Tower Hill to Cockham Wood SSSI (4 km west);
Northward Hill SSSI and High Halstow NNR (4 km north west);
Chattenden Woods SSSI (4 km north west);
Thames Estuary and Marshes Ramsar and SPA (6 km north west);
South Thames Estuary and Marshes SSSI (6 km north west);
Queendown Warren SAC and SSSI (10 km south); and
Benfleet and Southend Marshes Ramsar site, SPA and SSSI (10 km north).
13.7.68
These sites have previously been described in Table 13.3.
13.7.69
Nitrogen dioxide and nitric oxide are absorbed by vegetation. Their effects on plants
are additive and the scientific consensus is that they should be treated together.
Nitrogen is an essential plant nutrient and low exposure to nitrogen oxides can
promote growth. However, higher exposures can cause adverse effects including leaf
or needle damage and reduced growth. The point at which damage begins depends
on the species, on its nutritional state and on other environmental factors.
13.7.70
The United Nations Economic Commission for Europe (UNECE) and the World
Health Organisation (WHO) have developed a critical level at which the majority of
species should be protected. This is an annual mean of 30 g/m 3 (16 ppb) of nitrogen
oxides. This has been adopted as a European limit value in the Air Quality Daughter
Directive. In addition, the Government and the devolved administrations implemented
3
the Directive's annual mean limit value for the protection of vegetation of 30 g/m
(16 ppb).
June 2009
Page 206
SECTION 13
ECOLOGY
13.7.71
It is important to define the areas in which the limit values are to be achieved. The
Directive states that sampling points should be:
At least 5 km from major emission sources; or
20 km from an agglomeration, which is defined as an area with a population of
more than 250 000; and
Representative of areas of at least 1000 km2.
13.7.72
The government and devolved administrations intend that these objectives will apply
in those parts of the UK that are:
More than 20 km from an agglomeration; and
More than 5 km away from industrial sources regulated under Part A of the
Environmental Protection Act 1990;
More than 5 km from motorways; and
built up areas of more than 5000 people.
13.7.73
None of the objectives discussed above are considered to apply to the various
designated sites in the vicinity of the Damhead Creek 2 site, as none of the sites is
more than 5 km from a Part A installation or a motorway.
13.7.74
Nevertheless, an assessment has been undertaken which makes reference to the
limits and assesses the impact of Damhead Creek 2 on the designated sites within
10 km of the Damhead Creek 2 site with regard to air quality and deposition.
Existing Environment at the Designated Sites
13.7.75
The Air Pollution Information Service provides information on the existing ground level
concentrations, critical levels, critical loads and exceedances for sites in the UK.
13.7.76
Table 13.7 shows the information for the various sites identified above.
June 2009
Page 207
SECTION 13
ECOLOGY
TABLE 13.7: CRITICAL LEVELS AND LOADS AT DESIGNATED SITES FOR NOX AND NITROGEN
Existing NOx
Existing Nitrogen
Concentration as
Deposition
% of Critical
(kg N/ha/yr)
Level
Habitat
Existing NOx
Concentration
( g/m 3)
Critical Level of
NOx
( g/m 3)
Medway Estuary and Marshes SPA,
RAMSAR and SSSI
Salt Marsh
19.8
30
66.0
Dalham Farm SSSI
Shingle
rocks and
cliffs
20.4
30
Tower Hill to Cockerham Wood SSSI
Oak
Woodland
20.4
Norrthward Hill SSSI and High
Halstow NNR
Oak
Woodland
Critical Load of
Nitrogen
(kg N/ha/yr)
Existing Nitrogen
Deposition as %
of Critical Load
12.9
30
43.0
68.0
14.1
10
141.0
30
68.0
30.9
10
309.0
23.5
30
78.3
32.1
10
321.0
Oak
Woodland
20.5
30
68.3
32.1
10
321.0
Thames Estuary and Marshes SPA,
RAMSAR and SSSI
Salt Marsh
19.7
30
65.7
14.1
30
47.0
South Thames Estaury and Marshes
SSSI
Salt Marsh
19.7
30
65.7
14.1
30
47.0
Moist or wet
grassland
25.6
30
85.3
17.5
15
116.7
Salt Marsh
25.8
30
86.0
12.5
30
41.7
Site
SPA/RAMSAR
June 2009
Page 208
SECTION 13
ECOLOGY
13.7.77
The information in Table 13.7 indicates that the concentrations of NOx at the various
designated sites are within the critical levels. However, it is suggested that the critical
load for nitrogen is exceeded for a number of designated sites.
Modelling of Air Emissions from Damhead Creek 2
13.7.78
The modelling undertaken as part of the air quality assessment (discussed in
Section 10) also assessed the impacts to the European designated sites listed above.
13.7.79
The modelling has been assessed to determine the annual average contribution of
Damhead Creek 2 to NOx concentrations at the designated sites. Modelling has
assumed that Damhead Creek 2 operates in isolation for 8760 hours per year at base
load.
Critical Levels
13.7.80
Critical levels for annual ground level concentrations of NOx for the various
designated sites are as detailed above in Table 13.7. These can be compared with
the results of the dispersion modelling exercise to establish the likely impacts to the
designated sites resulting from Damhead Creek 2.
13.7.81
Table 13.8 shows the predicted increments to the existing background levels
identified by the Air Pollution Information System website for NO x at the various
designated sites due to operation of Damhead Creek 2. It should be noted that this
does not take into account any reductions as a result of Damhead Creek 2 operating
at lower output and assumes operation for 8760 hours per year.
June 2009
Page 209
SECTION 13
ECOLOGY
3
TABLE 13.8: EXPECTED INCREMENTS TO GROUND LEVEL CONCENTRATIONS OF NO2 AT DESIGNATED SITES ( g/m )
Predicted
Predicted Total
Increase in
Concentration as
Concentration as
% of Critical
% of Critical
Level
Level
Year
Existing NOx
Concentration
( g/m 3)
Critical Level of
NOx
( g/m 3)
Predicted
Increase in NOx
Concentration
( g/m 3)
Predicted Total
NOx
Concentration
( g/m 3)
RAMSAR and SSSI
2003
19.8
30
0.15
19.95
0.5
66.5
Dalham Farm SSSI
2003
20.4
30
0.20
20.60
0.7
68.7
2003
20.4
30
0.13
20.53
0.4
68.4
Norrthward Hill SSSI and High Halstow
NNR
2003
23.5
30
0.18
23.68
0.6
78.9
2003
20.5
30
0.17
20.67
0.6
68.9
RAMSAR and SSSI
2003
19.7
30
0.14
19.84
0.5
66.1
SSSI
2003
19.7
30
0.14
19.84
0.5
66.1
2005
25.6
30
0.10
25.70
0.3
85.7
SPA/RAMSAR
2004
25.8
30
0.16
25.96
0.5
86.5
Site
June 2009
Page 210
SECTION 13
ECOLOGY
13.7.82
The Table shows that the annual average increments to ground level concentrations
of NOx at the designated sites resulting from Damhead Creek 2 are all less than
0.3 g/m 3. Therefore these increments are less than 1 per cent threshold of the
critical level of 30 g/m3.
13.7.83
Damhead Creek 2 is therefore considered not to have a significant impact on air
quality at the designated sites within 10 km.
Effects of Deposition of Acidifying Pollutants
13.7.84
As well as contributing to ambient concentrations of oxides of nitrogen, the emissions
from Damhead Creek 2 have the potential to contribute to deposition of nitrogen.
Deposition of this pollutant can be a concern as this can lead to acidification effects
on soils and ecosystems. An assessment of the deposition effects of Damhead
Creek 2 emissions has been made to confirm the extent of any future contribution
from Damhead Creek 2.
13.7.85
Dry deposition is calculated using the following formula and values.
13.7.86
If the annual average ground level concentration of NOx is GC ( g/m-3) and the dry
deposition velocity is Vd (mm/s), then the annual dry deposition rate D (kg N/ha/yr)
can be calculated from:
D Vd GC C1 C 2
Where:
13.7.87
C1 converts NO2 to N, equal to C2 converts units to kg N/ha/yr, equal to -
14/46
0.315
The dry deposition velocity (Vd) is set to 0.0015 m/s (therefore 1.5 mm/s). This
represents the likely upper parameter range for dry deposition of these pollutants as
identified by the EA in Technical Guidance Note AQTAG 06.
The calculations assume an annual conversion of 100 per cent NOx to NO2. This is a
conservative estimate based on total conversion of NOx to NO2. In reality, this
conversion rate cannot be achieved, and as such the calculations are assuming a
worst case scenario.
13.7.88
Technical Guidance Note AQTAG 06 requires that the applicant also reports wet
deposition. This is achieved by application of conversion ratios to the dry deposition
results. The conversion ratios are dependent upon the area in which the deposition is
to occur. For the various designated sites the conversion ratio is 2-3 for NO 2. Here,
the conversion applied has assumed the likely upper parameter (i.e., the upper
conversion value).
13.7.89
To present the depositions as percentages, the lower critical load for Nitrogen is used.
13.7.90
The dry and wet deposition values are presented for the modelled data in Table 13.9.
June 2009
Page 211
SECTION 13
ECOLOGY
TABLE 13.9: EXPECTED INCREMENTS TO NITROGEN DEPOSITION AT THE DESIGNATED SITES (Kg N/ha/yr)
Site
Minimum
Predicted
Critical Load of Increase in Dry
Nitrogen
Deposition
(kg N/ha/yr)
(kg N/ha/yr)
Predicted
Predicted
Predicted
Increase in Wet
Increase in Dry
Increase in Wet
Deposition as
Deposition as
Deposition
% of Critical
% of Critical
(kg N/ha/yr)
Load
Load
Predicted
Increase in
Total
Deposition
(kg N/ha/yr)
Predicted
Increase in
Total
Deposition as
% of Critical
Load
RAMSAR and SSSI
30
0.022
0.07
0.065
0.22
0.086
0.29
Dalham Farm SSSI
10
0.029
0.29
0.086
0.86
0.115
1.15
10
0.019
0.19
0.056
0.56
0.075
0.75
Norrthward Hill SSSI and High Halstow NNR
10
0.026
0.26
0.078
0.78
0.104
1.04
10
0.024
0.24
0.073
0.73
0.098
0.98
RAMSAR and SSSI
30
0.020
0.07
0.060
0.20
0.081
0.27
South Thames Estaury and Marshes SSSI
30
0.020
0.07
0.060
0.20
0.081
0.27
15
0.014
0.10
0.043
0.29
0.058
0.38
SPA/RAMSAR
30
0.023
0.08
0.069
0.23
0.092
0.31
June 2009
Page 212
SECTION 13
ECOLOGY
Critical Loads
13.7.91
In order to properly assess the impact of the results presented in Table 13.9, the
predicted total deposition of nitrogen is presented in Table 13.10 alongside the
relevant critical loads for the various designated sites.
13.7.92
In addition, Table 13.11 presents the results of nitrogen deposition in terms of
keq/ha/yr. This is a unit of ‘equivalents’ which is used instead of mass as a measure
of acidification. This term is essentially ‘moles of charge’. Technical Guidance Note
AQTAG 06 states that this is a measure of how acidifying the chemical species can
be.
13.7.93
To convert from kg N/ha/yr to keq/ha/yr, the following conversion should be used:
(keq / ha / yr )
Where:
June 2009
(kg N / ha / yr ) C
C is equal to - 1/14
Page 213
SECTION 13
ECOLOGY
TABLE 13.10: CONTRIBUTION OF NITROGEN DEPOSITION TO CRITICAL LOADS AT THE DESIGNATED SITES (Kg N/ha/yr)
Minimum Critical
Load of Nitrogen
(kg N/ha/yr)
Existing Deposition
of Nitrogen
(kg N/ha/yr)
Predicted Increase
in Total Deposition
(kg N/ha/yr)
Predicted Total
Deposition
(kg N/ha/yr)
Predicted Total
Deposition as % of
Critical Load
Medway Estuary and Marshes SPA, RAMSAR and SSSI
30
12.9
0.086
12.99
43.3
Dalham Farm SSSI
10
14.1
0.115
14.22
142.2
10
30.9
0.075
30.97
309.7
10
32.1
0.104
32.20
322.0
10
32.1
0.098
32.20
322.0
Thames Estuary and Marshes SPA, RAMSAR and SSSI
30
14.1
0.081
14.18
47.3
30
14.1
0.081
14.18
47.3
15
17.5
0.058
17.56
117.1
Benfleet and Southend Marshes SPA/RAMSAR
30
12.5
0.092
12.59
42.0
Site
June 2009
Page 214
SECTION 13
ECOLOGY
TABLE 13.11: CONTRIBUTION OF NITROGEN DEPOSITION TO CRITICAL LOADS AT THE DESIGNATED SITES (Keq/ha/yr)
Minimum Critical
Load of Nitrogen
(keq/ha/yr)
Existing Deposition
of Nitrogen
(keq/ha/yr)
Predicted Increase
in Total Deposition
(keq/ha/yr)
Predicted Total
Deposition
(keq/ha/yr)
Predicted Total
Deposition as % of
Critical Load
2.14
0.921
0.006
0.928
43.3
Dalham Farm SSSI
0.71
1.007
0.008
1.015
142.2
0.71
2.207
0.005
2.212
309.7
0.71
2.293
0.007
2.300
322.0
0.71
2.293
0.007
2.300
322.0
2.14
1.007
0.006
1.013
47.3
2.14
1.007
0.006
1.013
47.3
1.07
1.250
0.004
1.254
117.1
2.14
0.893
0.007
0.899
42.0
Site
June 2009
Page 215
SECTION 13
ECOLOGY
13.7.94
Table 13.10 and Table 13.11 show that when the lower critical load figures are
applied, the critical loads are exceeded at the great majority of the designated sites.
However, it can clearly be seen that Damhead Creek 2 makes an insignificant
contribution to this.
Noise and Vibration Effects
13.7.95
The increased levels of road traffic will result in locally increased levels of noise and
vibration, as discussed in Section 11 of this ES. Associated disturbance impacts on
flora and non-mobile fauna from the operational power station are considered
negligible from the existing baseline. Whilst there is inconclusive evidence of the
effects of noise and vibration on wildlife, it is considered that many of the species
present are likely to habituate to living in an active power station environment.
Lighting Effects
13.7.96
Damhead Creek 2 will be subject to minimal night-time lighting, which will be directed
towards the operational areas and away from any retained or created habitats on the
13.7.97
The impact of lighting during the operational phase of Damhead Creek 2 is not
considered to be significant. Damhead Creek 2 is sited adjacent to the existing
Damhead Creek CCGT Power Station and therefore there will be an increase in
lighting levels only so far as an extension of lighting levels that already exists on site
to encompass the new operational area. It is considered that the majority of
associated species in the surroundings will have already habituated to lighting in the
local area and will readily adapt to this negligible increase. Specific impacts of
lighting and bats are considered below.
Summary
13.7.98
The effect of these impacts on the various Designated Sites, Habitats and Species is
discussed below. A summary of the potential unmitigated impacts from operation,
described above, are provided in Table 13.12.
Designated Sites
13.7.99
With the exception of the Medway Estuary and Marshes (discussed below) the
designated sites are considered to be sufficiently distant from Damhead Creek 2 to
not be subject to the impacts identified above. As such potential impacts to these
designated sites are considered to be not significant.
13.7.100
Areas 1 and 2 comprise the operational features of Damhead Creek 2. The
operational processes associated with these areas will not generate significant
disturbance that could affect the interest features of the estuary. Furthermore both
Areas 1 and 2 are considered to be sufficiently distant from the estuary to further
reduce any negligible disturbance that might be generated. Following construction,
Area 3 will not be subject to operational use. As such, operational impacts to the
Medway Estuary and Marshes Designated site and the associated interest features
are considered negligible and not significant.
13.7.101
Discharge into the Medway Estuary will be minimal and as such considered not
significant.
Habitats
Water Bodies
13.7.102
Potential effects to water bodies during the operation of Damhead Creek 2 are limited
to pollution to water bodies adjacent to Area 1. This may arise from surface water
drainage from roads, buildings and hard standing areas. This impact is considered to
be medium magnitude and significant at a County level.
June 2009
Page 216
SECTION 13
ECOLOGY
Species
Badger
13.7.103
Based on the impacts identified, no potential effects to badgers are predicted during
the operation of Damhead Creek 2.
Water Vole
13.7.104
Potential effects to water voles during the operation of Damhead Creek 2 are
associated with water pollution which could result in harm to water voles and/or
degradation to their habitat.
13.7.105
This potential impact is considered to be of medium magnitude and significant at a
local level.
Bats
13.7.106
Potential effects to bats during the operation of Damhead Creek 2 are limited to
disturbance principally through additional lighting.
13.7.107
A number of bat species use lighting for foraging, due to the lights attracting moths
and other flying insects, and this could be considered to be a positive effect.
However, there may be negative effects on other species due to disturbance and
increased risk of predation.
13.7.108
Lighting can be particularly harmful along important corridor routes, such as river
corridors, as lit areas can effectively cause a barrier through which bats will not pass.
As such, the effects of this impact are likely to be of low magnitude and as such
significant at a local level.
Breeding Birds
13.7.109
Based on the impacts identified, no potential effects to breeding birds are predicted
during the operation of Damhead Creek 2.
Reptiles
13.7.110
Based on the impacts identified, no potential effects to reptiles are predicted during
the operation of Damhead Creek 2.
Amphibians
13.7.111
Potential effects to amphibians, principally great crested newts, during the operation
of Damhead Creek 2 are associated with water pollution that could result in harm to
great crested newts and/or degradation to their habitat.
13.7.112
local level.
13.7.113
Based on the impacts identified, no potential effects to terrestrial invertebrates are
predicted during the operation of Damhead Creek 2.
Aquatic invertebrates
13.7.114
Potential effects to aquatic invertebrates, during the operation of Damhead Creek 2
are associated with water pollution that could result in harm to great crested newts
and/or degradation to their habitat.
13.7.115
local level.
June 2009
Page 217
SECTION 13
ECOLOGY
TABLE 13.12: SUMMARY OF UNMITIGATED OPERATION IMPACTS
VER
Value
Type of Impact
Confidence,
Duration and
Reversibility
Medway Estuary and
Marshes SPA/Ramsar/SSSI
(including bird assemblage)
International
N/A
Negligible – Area 3 is not subject to
use post development.
N/A
Not Significant
All other European
Designated sites
International
N/A
N/A
Not Significant
All other Nationally
Designated sites
National
N/A
N/A
Not Significant
Water bodies including:
ponds ditches,
saline/brackish lagoons and
County
Pollution
Medium – Potential effect to water
bodies associated with the WCA.
Possible,
Long term,
Significant
County level
Reversible
Badger
Local
N/A
Water Vole
Local
Pollution
N/A
Medium – Potential effect to
population associated with the WCA.
N/A
Page 218
Not Significant
Possible,
Significant
Long term,
Local level
Reversible
June 2009
Significance of
Impact
SECTION 13
ECOLOGY
VER
Bats
Value
Type of Impact
Confidence,
Duration and
Reversibility
Local
Disturbance through increased
lighting
Low – Small numbers of bats present,
effects of lighting vary depending on
species.
Possible,
Significant
Long term,
Local level
Significance of
Impact
Reversible
Breeding Birds
County
N/A
N/A
N/A
Not Significant
Reptiles
District
N/A
N/A
N/A
Not Significant
Local
Pollution
Amphibians
Medium - Potential effect to population
associated with the WCA.
Possible,
Significant
Long term,
Local level
Reversible
Local
N/A
Local
Pollution
N/A
Medium - Potential effect to population
associated with the WCA.
N/A
Possible,
Significant
Long term,
Local level
Reversible
June 2009
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Not Significant
SECTION 13
ECOLOGY
13.8
Mitigation
13.8.1
Ecological mitigation measures that are required are often complementary to those
needed to reduce or offset impacts on other aspects of the environment. For
example, mitigation of landscape and visual impacts can often be combined with
ecological measures.
13.8.2
Within the context of the Ecological Impact Assessment, mitigation is one of a
hierarchy of measures that are undertaken to prevent or reduce adverse impacts.
Mitigation measures can include:
Avoidance / Prevention Measures
These are measures taken to avoid or prevent adverse impacts, and can include:
scheme layout or timing of site works.
Reduction / Mitigation Measures
These are measures taken to reduce adverse impacts and can include: retaining
walls and pollution interceptors.
Compensation / Offsetting Measures
These are measures taken to offset significant residual adverse impacts and are
for those measures that cannot be entirely avoided or mitigated to the point that
they become insignificant. They will include habitat creation and / or
enhancement.
13.8.3
In this section, mitigation measures are proposed for all significant ecological impacts
on the habitats and species identified in the preceding sections. Generic mitigation
measures include best practice methods and general principles that can be applied to
Damhead Creek 2 as a whole, and are relevant to all habitats and species. As
summarised in the opening paragraphs of this section, prevention or avoidance of
these adverse impacts is the primary aim of ecological mitigation. If this is not
possible measures would be proposed to reduce the impact and if this is also not
possible then measures to offset the impact would be included in the mitigation
strategy.
13.8.4
It should be noted that a substantial level of mitigation has previously been
implemented by ScottishPower across a wide area and ScottishPower has
demonstrated its commitment to biodiversity through ongoing monitoring and
management of these areas for biodiversity gain with some notable successes
including the establishment of a reedbed supporting breeding marsh harrier.
13.8.5
corridor. In combination these areas effectively surround Area 3 of the development
grassland.
13.8.6
Indeed the mitigation works undertaken and the mitigation land put aside for the
existing Damhead Creek CCGT Power Station were designed and agreed to offset
and compensate for both the existing Damhead Creek CCGT Power Station and
Damhead Creek 2. In light of this, it is considered that the mitigation land already in
existence will go some way to offsetting impacts associated with Damhead Creek 2.
Furthermore, it is considered that opportunities for further enhancement and
management of some areas of the existing mitigation land would provide additional
biodiversity gains; these are discussed in further detail below.
June 2009
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ECOLOGY
13.8.7
However, it is recognised that due to the permanent loss of habitats that support
protected species it will be necessary to implement additional mitigation strategies to
offset potential impacts and ensure legal compliance. The detailed design of such
mitigation is not within the scope of this ES and will come forward in consultation with
the planning authority. However, a broad overview of the nature of such work is
provided.
Due to the legislative requirements for much of the ecological
mitigation/compensation work, detailed method statements and designs will be
required for securing protected species licences and it is at this stage the detailed
mitigation will be presented.
Generic Mitigation
13.8.8
The implementation of a Construction Environmental Management Plan (CEMP) by
the appointed contractor and the development of a Works Method Statement to
illustrate how impacts on ecology will be managed will be created. Good construction
site management will be implemented to avoid / minimise generation of excessive
litter, dust, noise and vibration. This will be controlled and monitored through the
CEMP. Measures will be implemented to avoid/minimise potential for problems such
as fuel and other chemical spills.
There will be no storage of potentially
contaminating materials in areas of hydrological sensitivity, such as in the vicinity of
the Estuary or the WCA. A Pollution Incident Response Plan will be included as part
of the CEMP to ensure that impacts from any potential accidental spills can be
reduced to a minimum.
13.8.9
In addition, the following measures to avoid impacts should be included in the CEMP:
Ensure that work compounds and access tracks etc are not located in, or
adjacent to, areas that maintain habitat value;
Establish site fencing to prevent access to areas outside working areas,
particularly in areas adjacent to features of interest/value;
Implement procedures to cover site safety issues, including storage of potentially
dangerous materials;
Provide briefings and instruction to contractors regarding the biodiversity issues
present on the site; and
Follow pollution prevention guidelines provided by the Environment Agency
(e.g., PPG 01, PPG 02, PPG 03, PPG 05 and PPG 06) to prevent pollution of
water courses from silt or chemicals.
13.8.10
To reduce construction impacts the following will be implemented:
Restrict workforce to working areas through the erection of fencing, to prevent
additional damage;
Best practice methods would be followed throughout; and
Establish protocols and contingency plans for dealing with incidents should they
arise.
13.8.11
It is considered that the establishment of the CEMP with the incorporation of the
above key principals will directly offset the construction impacts of Damhead Creek 2
in terms of disturbance and habitat degradation for a number of the VERs for which
significant environmental impacts have been identified.
Specific Mitigation of Impacts to VERs
Medway Estuary and Marshes SPA/Ramsar/SSSI
13.8.12
The potential disturbance effects to the estuary can be reduced in a number of ways.
Wherever possible timing of works outside of the wintering period will effectively
reduce disturbance effects to a negligible level however it is unlikely to be realistic to
June 2009
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SECTION 13
ECOLOGY
implement such a strategy over a three year construction schedule. As such the
works programme should consider the scheduling of the most disturbing activities
(subject to consultation) to coincide with periods of low waterbird activity.
13.8.13
To further reduce visual impacts throughout all periods of construction activity in
Area 3, a visual screen could be established. To some extent the estuary is already
screened from this area by an earth/spoil bank. However, it is considered that the
installation of a semi permanent soil (or similar) bank (which could also be developed
for additional species mitigation), would substantially reduce the likelihood of
disturbance (principally visual and noise) to a negligible magnitude and as such offset
the impacts identified for this VER during the construction stage.
Water Bodies
13.8.14
Aside from providing a valuable ecological feature, the water bodies within the
Damhead Creek 2 site provide an important hydrology function (as discussed in
Section 15). As such, some of the water bodies in Area 3 that will be permanently
lost during construction will be compensated for on at least a 1:1.25 ratio in terms of
volume of water and length of bank side habitat.
13.8.15
The specific design and location of these replacement water bodies will be subject to
a detailed mitigation strategy and method statement. However the broad features of
the design and development include,
Established at least 1 year in advance of other water bodies being removed;
Located in areas that will not be subject to further development and /or impacts
from nearby development operations (including the proposed development);
Connected with existing water bodies and habitats;
Appropriate bank side profiles and planting to provide optimal habitat for water
voles;
Translocation of some plants and species (principally invertebrates) from water
bodies subject to loss; and
Long term management prescriptions (as part of an overarching ecological
management plan) to maintain their ecological value.
13.8.16
It is considered that the establishment of these water bodies with the incorporation of
the above key principals will directly offset the construction impacts of Damhead
Creek 2in terms of permanent habitat loss for several VERs and result in impacts of
negligible magnitude and as such not significant.
Badger
13.8.17
By implementing the mitigation set out for prevention and avoidance of impacts
detailed in the generic mitigation section above, it is considered that the potential
disturbance effects to badgers during the construction period are offset to result in
any effects being not significant.
13.8.18
Risks of mortality to badgers can be offset by management of site traffic in terms of
speed limits and routes and by ensuring trenches and pits are covered or include a
crawl board at night when badgers would be active. It is considered that these
measures would provide sufficient mitigation to reduce any impacts to badgers as not
significant.
Water Vole
13.8.19
Water voles and their habitat are protected under the Wildlife and Countryside Act
1981 (as amended). As such, without mitigation the impacts identified for this species
arising from the construction activities would potentially result in a legal offence being
committed.
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ECOLOGY
13.8.20
In essence the legislation does not permit licences to be issued in relation to
development of land. Therefore it will be necessary to demonstrate that Damhead
Creek 2 has considered all options available in order to avoid the need for removal of
water vole habitat in Area 3 within the Damhead Creek 2 site.
13.8.21
Guidance from Natural England1 identifies that the capture of water voles for
translocation from a site is unlikely to be considered the "incidental result of other
activities" and so is not covered by the defence in the recently revised legislation.
However, if despite all reasonable efforts, properly authorised development will
adversely impact on water voles and there are no alternative habitats nearby, Natural
England may be able to issue a licence to trap and translocate water voles for the
purpose of conservation. In order to issue such a licence, Natural England would
need to be assured that there is no reasonable alternative to the development or
maintenance work and that there are no other practical solutions which would allow
water voles to be retained at the same location. Natural England will need to be
assured that the mitigation strategy and compensation will result in a positive
contribution to water vole conservation.
13.8.22
Accordingly, to ensure that potential impacts to water voles are avoided and to ensure
compliance with the legal requirements, in conjunction with the development of new
habitat (as outlined above), it will be necessary to undertake updated surveys
between 12 and 24 months prior to construction to fully assess the water vole status
within the affected areas (and within an appropriate zone of influence), devise a
detailed mitigation plan and method statement specific to this species documenting
the habitat compensation and a translocation methodology following the best practice
outlined in Strachen & Moorhouse (2007) 8. It is proposed that pre-construction
update surveys will be completed post consent.
13.8.23
By ensuring that the outline guidance presented above is implemented it is
considered that the identified significant impacts to water voles would be offset and
the construction activities would be legally compliant in regard to the protection
afforded to water voles.
Bats
13.8.24
Construction and operational lighting will, wherever possible, utilise low pressure
sodium lamps or high pressure sodium instead of mercury or metal halide lamps.
Lighting will be directed to where it is needed and light spillage avoided. This will be
achieved by the design of the luminaire and by using accessories such as hoods,
cowls, louvres and shields to direct the light to the intended area only.
13.8.25
With the additional water body compensation it is considered that the identified
potential negative effects to bats will be of negligible magnitude and not significant.
Birds
13.8.26
To comply with the legal protection afforded to breeding birds, the clearance of any
breeding habitat will need to be undertaken outside of the breeding season (March to
September). In the event this is not feasible, a nest check survey will be required to
identify the absence of breeding birds before habitat clearance can be implemented.
13.8.27
In line with other VERs as per below, the site wide mitigation measures will ensure
that optimal breeding habitat for the species assemblage is maintained across the
Damhead Creek 2 site. This will include nesting habitat, foraging habitat and
appropriate winter habitat. Given the relatively small areas of optimal breeding bird
habitat that will be lost it is considered that this mitigation is appropriate to offset the
potential negative effects to breeding birds.
1
Water voles – the law in practice Guidance for Planners and Developers. Natural England 2008
June 2009
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SECTION 13
ECOLOGY
Reptiles
13.8.28
A Mitigation Strategy for reptiles will be prepared that ensures potential impacts to the
species are minimised and that the construction activities comply with the legal
obligations required. The strategy will be developed to compliment mitigation for
great crested newts (as set out below).
13.8.29
It is considered that based on the existing condition and management of some areas
of the mitigation land, principally grassland areas, there is scope to provide
enhancement and increase the suitability of the habitats to support flora and fauna
through adaptation of the management plan and some additional activities.
13.8.30
Due to the permanent loss of reptile habitat, areas of sub optimal habitat within the
existing mitigation land (including some areas of the WCA) will be adapted/enhanced
to provide compensatory habitat for reptiles. Areas identified that could be enhanced
include sections of the WCA grassland areas, sheltered areas of the coastal corridor
(primarily to the south west) and some of the grassland areas on the north west
Exclusion area. In addition to the existing mitigation land there is scope to enhance
the bund between the WCA and Area 3 on the north eastern side. At present this
bank is of very limited conservation value and has the potential to be developed into
suitable habitat that will also be beneficial in increasing the width and functionality of
the corridor features that the mitigation area provides.
13.8.31
The ways in which the habitats can be further enhanced include appropriate earth and
vegetation management to provide optimal reptile conditions and the creation of
reptile hibernacula. For example by altering the current mowing regime and adopting
a multi-rotational cutting of the coastal grasslands would create a mosaic of different
sward heights that would provide both, basking, foraging and shelter habitats for
reptile species. Increased, managed, scrub development in the grassland areas
would also provide increased areas of shelter, and where flowering species are
concerned, increased invertebrate fauna for foraging reptiles.
Mitigation
enhancement will also consider opportunities for topographical alterations and
adapting banks and bunds to provide a physical increase in the total area of suitable
reptile habitat available thereby increasing the carrying capacity.
13.8.32
These activities will be undertaken to ensure continued connectivity across the
Damhead Creek 2 site and beyond.
13.8.33
As a result of these actions it is considered that the potential negative impacts to
reptiles would be of negligible magnitude and as such not significant.
Amphibians
13.8.34
A Mitigation Strategy for great crested newts will be prepared that ensures potential
impacts to the species are minimised and that the construction activities comply with
the legal obligations required.
13.8.35
Given the apparently limited distribution of great crested newts across the Damhead
Creek 2 site, it is considered that terrestrial habitat is not likely to be the limiting factor
on this population and that the WCA provides sufficient habitat for the existing
population and allowance for population growth.
13.8.36
As the WCA was, in part, created for the specific purpose of great crested newt
habitat compensation for the combined developments (the existing Damhead Creek
CCGT Power Station and Damhead Creek 2) and will be retained under the Damhead
Creek 2 development, it is considered that it should be possible to exclude the WCA,
and as such the great crested newts, from the Damhead Creek 2 site under a
permitted licence from Natural England without the need for a translocation scheme.
great crested newts would be of negligible magnitude and as such not significant. In
June 2009
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SECTION 13
ECOLOGY
the event that great crested newts are encountered within the development site then a
suitable mitigation strategy will be implemented.
13.8.37
In line with the proposed habitat enhancement works to the existing mitigation land,
the enhancement provisions will be of benefit to terrestrial invertebrates, in part to
ensure a food source for herpetiles. Specific enhancement would be targeted to the
key species identified during the monitoring and survey work and is considered
appropriate to offset the impacts identified for terrestrial invertebrates.
13.8.38
The establishment of replacement water bodies to offset those being lost will largely
offset the negative impacts identified for aquatic invertebrates. Translocation of
aquatic invertebrates into the new water bodies will further ensure the long term
viability of this VER. As a result of these actions it is considered that the potential
negative impacts to aquatic invertebrates would be of negligible magnitude and as
such not significant.
13.9
13.9.1
Table 13.13 summarises the residual effects to VERs once all the mitigation
measures detailed above have been implemented.
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SECTION 13
ECOLOGY
TABLE 13.13: SUMMARY OF RESIDUAL EFFECTS TO VERS POST MITIGATION
VER
Value
Type of Impact
Phase
Mitigation
Significance of
Impact
Disturbance and risk of
pollution.
Construction and
Operation.
General Best Practice
Not Significant
Medway Estuary and Marshes
SPA/Ramsar/SSSI (including
bird assemblage)
International
All other European Designated
sites
International
N/A
N/A
N/A
Not Significant
All other Nationally Designated
sites
National
N/A
N/A
N/A
Not Significant
Water bodies including; ponds
ditches, saline/brackish lagoons
and associated marginal habitats
County
Permanent habitat loss.
Construction and
Operation.
Not Significant
Construction and
Operation.
Not Significant
Construction and
Operation.
General Best Practice.
Not Significant
Construction and
Operation.
Badger
Screening
pollution.
Local
Disturbance.
Mortality.
Water Voles
Timing of works
Local
Fragmentation.
Habitat Compensation
pollution.
Mortality.
Bats
Local
Disturbance.
and enhancement
Sensitive Lighting
June 2009
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Not Significant
SECTION 13
ECOLOGY
VER
Value
Type of Impact
Phase
Mitigation
Significance of
Impact
Breeding Birds
County
Construction and
Operation.
Not Significant
Construction and
Operation.
Construction and
Operation.
Construction and
Operation.
Construction and
Operation.
Disturbance.
Mortality.
Reptiles
District
Fragmentation.
pollution.
and Enhancement
Not Significant
and Enhancement
Mortality.
Amphibians
Local
Fragmentation.
pollution.
Not Significant
and Enhancement
Mortality.
Local
pollution.
Not Significant
and Enhancement
Mortality.
Local
pollution.
Mortality.
June 2009
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and Enhancement
Not Significant
SECTION 13
ECOLOGY
13.10
13.10.1
The development of both the proposed Kingsnorth Units 5 and 6 and Kingsnorth
Business Park proposed by Goodman Developments Limited (from which some of the
baseline data for this Section has been considered) have the potential to result in
cumulative effects that could adversely alter the findings of this assessment for a
number of VERs.
13.10.2
This section details possible cumulative effects as a result of these developments.
13.10.3
However, it is considered that a strategic approach to the mitigation for VERs by all
developers has the potential to result in the opportunities for positive effects.
13.10.4
As identified by the above assessment, there is scope for further biodiversity
enhancement through the coordination of mitigation and compensation measures and
a holistic approach to the biodiversity of the total area rather than a scheme by
scheme piecemeal approach. As such it is recommended that wherever feasible
collaboration is undertaken with the incorporation of the relevant statutory and nonstatutory consultees such as Natural England and the Environment Agency to ensure
that the full biodiversity potential for the area is realised.
Air Quality
13.10.5
As discussed above, the operation of Damhead Creek 2 may lead to changes in air
quality at the nearby designated wildlife sites. Cumulative impacts with regard to
Damhead Creek 2's operation in conjunction with the existing Kingsnorth Power
Station and the existing Damhead Creek CCGT Power Station can be ignored as
contributions from these plants are already included in the existing background, and
are therefore incorporated in the existing baseline. However it is necessary to
consider Damhead Creek 2 operating in conjunction with the proposed Kingsnorth
Units 5 and 6.
13.10.6
The modelling undertaken as part of the cumulative air quality assessment discussed
in Section 10 also assessed the impacts to the European designated sites and follows
a similar methodology as detailed previously for the air quality effects of Damhead
Creek 2 operating in isolation.
13.10.7
The modelling has been assessed to determine the annual average contribution of
the plant to NOx concentrations at the designated sites. Modelling has assumed that
Damhead Creek 2 and the Kingsnorth Units 5 and 6 operate for 8760 hours per year
at base load.
Critical Levels
13.10.8
Critical levels for annual ground level concentrations of NOx for the various
designated sites are as detailed above in Table 13.7. These levels can be compared
with the results of the dispersion modelling to establish the likely impacts to the
designated site resulting from the operation of Damhead Creek 2 in conjunction with
the proposed Kingsnorth Units 5 and 6.
13.10.9
Table 13.14 shows the predicted increments to the existing background levels.
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ECOLOGY
TABLE 13.14: EXPECTED CUMULATIVE INCREMENTS TO GROUND LEVEL CONCENTRATIONS OF NOX AT THE DESIGNATED
3
SITES ( g/m )
Predicted
Predicted Total
Increase in
Concentration as
Concentration as
% of Critical
% of Critical
Level
Level
Year
Existing NOx
Concentration
( g/m 3)
Critical Level of
NOx
( g/m 3)
Predicted
Increase in NOx
Concentration
( g/m 3)
Predicted Total
NOx
Concentration
( g/m 3)
RAMSAR and SSSI
2003
19.8
30
0.48
20.28
1.6
67.6
Dalham Farm SSSI
2003
20.4
30
0.82
21.22
2.7
70.7
2003
20.4
30
0.58
20.98
1.9
69.9
Norrthward Hill SSSI and High Halstow
NNR
2003
23.5
30
0.80
24.30
2.7
81.0
2003
20.5
30
0.77
21.27
2.6
70.9
RAMSAR and SSSI
2003
19.7
30
0.66
20.36
2.2
67.9
SSSI
2003
19.7
30
0.66
20.36
2.2
67.9
2005
25.6
30
0.41
26.01
1.4
86.7
SPA/RAMSAR
2004
25.8
30
0.60
26.40
2.0
88.0
Site
June 2009
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SECTION 13
ECOLOGY
13.10.10
The Table shows that the annual average increments to ground level concentrations
of NOx at the designated sites resulting from the operation of Damhead Creek 2 in
conjunction with the proposed Kingsnorth Units 5 and 6 peak at 0.8 g/m3 well below
the critical level of 30 g/m3.
13.10.11
However, this does not allow for the decommissioning of the existing Kingsnorth
Power Station which makes a substantial contribution to the existing back ground
baseline concentrations. The decommissioning of the existing Kingsnorth Power
Station will greatly reduce NOx levels in the surrounding area. There may therefore
be a net improvement in ground level concentrations at the various designated sites.
13.10.12
The operation of the proposed Kingsnorth Units 5 and 6 and Damhead Creek 2 in
conjunction is therefore considered not to have a significant impact on air quality at
the designated sites.
Effects of Deposition of Acidifying Pollutants
13.10.13
Nitrogen deposition is presented in Table 13.15 for the operation of Damhead Creek 2
in conjunction with the proposed Kingsnorth Units 5 and 6 based on the approach
identified previously for the air quality effects of Damhead Creek 2 operating in
isolation.
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SECTION 13
ECOLOGY
TABLE 13.15: EXPECTED INCREMENTS TO NITROGEN DEPOSITION AT THE DESIGNATED SITES (KG N/HA/YR)
Site
Minimum
Predicted
Critical Load of Increase in Dry
Nitrogen
Deposition
(kg N/ha/yr)
(kg N/ha/yr)
Predicted
Predicted
Predicted
Increase in Wet
Increase in Dry
Increase in Wet
Deposition as
Deposition as
Deposition
% of Critical
% of Critical
(kg N/ha/yr)
Load
Load
Predicted
Increase in
Total
Deposition
(kg N/ha/yr)
Predicted
Increase in
Total
Deposition as
% of Critical
Load
RAMSAR and SSSI
30
0.069
0.23
0.207
0.69
0.276
0.92
Dalham Farm SSSI
10
0.118
1.18
0.354
3.54
0.472
4.72
10
0.084
0.84
0.251
2.51
0.334
3.34
10
0.115
1.15
0.346
3.46
0.461
4.61
10
0.111
1.11
0.333
3.33
0.443
4.43
RAMSAR and SSSI
30
0.095
0.32
0.285
0.95
0.380
1.27
30
0.095
0.32
0.285
0.95
0.380
1.27
15
0.059
0.39
0.177
1.18
0.236
1.57
SPA/RAMSAR
30
0.086
0.29
0.259
0.86
0.346
1.15
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SECTION 13
ECOLOGY
Critical Loads
13.10.14
In order to properly assess the impact of the results presented in Table 13.15 the
predicted total deposition of nitrogen is presented in Table 13.16 and Table 13.17
alongside the relevant critical loads for the various designated sites.
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TABLE 13.16: CUMULATIVE CONTRIBUTION OF NITROGEN DEPOSITION TO CRITICAL LOADS AT THE DESIGNATED SITES
(KG N/HA/YR)
Site
Minimum Critical
Load of Nitrogen
(kg N/ha/yr)
Existing Deposition
of Nitrogen
(kg N/ha/yr)
Predicted Increase
in Total Deposition
(kg N/ha/yr)
Predicted Total
Deposition
(kg N/ha/yr)
Predicted Total
Deposition as % of
Critical Load
30
12.9
0.276
13.18
43.9
Dalham Farm SSSI
10
14.1
0.472
14.57
145.7
10
30.9
0.334
31.23
312.3
10
32.1
0.461
32.56
325.6
10
32.1
0.443
32.54
325.4
30
14.1
0.380
14.48
48.3
30
14.1
0.380
14.48
48.3
15
17.5
0.236
17.74
118.2
30
12.5
0.346
12.85
42.8
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ECOLOGY
TABLE 13.17: CUMULATIVE CONTRIBUTION OF NITROGEN DEPOSITION TO CRITICAL LOADS AT THE DESIGNATED SITES
(KEQ/HA/YR)
Site
Minimum Critical
Load of Nitrogen
(keq/ha/yr)
Existing Deposition
of Nitrogen
(keq/ha/yr)
Predicted Increase
in Total Deposition
(keq/ha/yr)
Predicted Total
Deposition
(keq/ha/yr)
Predicted Total
Deposition as % of
Critical Load
2.14
0.921
0.020
0.941
43.9
Dalham Farm SSSI
0.71
1.007
0.034
1.041
145.7
0.71
2.207
0.024
2.231
312.3
0.71
2.293
0.033
2.326
325.6
0.71
2.293
0.032
2.325
325.4
2.14
1.007
0.027
1.034
48.3
2.14
1.007
0.027
1.034
48.3
1.07
1.250
0.017
1.267
118.2
2.14
0.893
0.025
0.918
42.8
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SECTION 13
ECOLOGY
13.10.15
Table 13.16 and Table 13.17 show that when the lower critical load figures are
applied, the critical loads are exceeded at the great majority of the designated sites.
However, it can clearly be seen that the operation of Damhead Creek 2 in conjunction
with the proposed Kingsnorth Units 5 and 6 make an insignificant contribution to this.
Noise and Vibration Effects
13.10.16
The increased levels of road traffic will result in locally increased levels of noise and
vibration, as discussed in Section 11 of this ES. Impacts on flora and non-mobile
fauna from the operational power stations (existing Kingsnorth Power Station and
Damhead Creek Power Station) are considered negligible from the existing baseline.
Whilst there is inconclusive evidence of the effects of noise and vibration on wildlife,
many of the species present appear habituated to living in an active power station
environment.
13.10.17
The construction and operation of the proposed Kingsnorth Units 5 and 6, Damhead
Creek 2 and the Kingsnorth Business Park are therefore not expected to have a
significant environmental impact.
Lighting Effects
13.10.18
Damhead Creek 2 will be subject to minimal night-time lighting, which will be directed
towards the operational areas and away from any retained or created habitats on the
Damhead Creek 2 site. This will no doubt be the case for the proposed Kingsnorth
Units 5 and 6 and the Kingsnorth Business Park project as well.
13.10.19
The impact of lighting during the operational phase of the proposed Kingsnorth Units
5 and 6, Damhead Creek 2 and the Kingsnorth Business Park project is not
considered to be significant. The proposed power stations are both sited adjacent to
the existing power stations. Any increase in lighting levels will only be a result of
Damhead Creek 2 of existing lighting levels on site to encompass the new power
station units. It is considered that the majority of associated species in the
surroundings will have already habituated to lighting in the local area and will readily
adapt to this increase.
13.10.20
The construction and operation of the proposed Kingsnorth Units 5 and 6, Damhead
Creek 2 and the Kingsnorth Business Park are therefore not expected to have a
significant environmental impact.
June 2009
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SECTION 14
WATER QUALITY
14
WATER QUALITY
14.1
Summary
14.1.1
The supply of water for construction of Damhead Creek 2 will be the responsibility of
the construction contractor. It is expected that the water source will be the existing
towns water supply to the existing Damhead Creek CCGT Power Station site. An
alternative to this would be to source water from boreholes beneath the site. This
alternative is currently being investigated at the existing Damhead Creek CCGT
Power Station, and would be used to source water for on site treatment and use.
14.1.2
The discharge of any effluents during construction, including site drainage, will also
be the responsibility of the construction contractor, who will be required by
ScottishPower to reach agreement with the Environment Agency and the local
sewerage undertakers, Southern Water, with regard to the detailed methods of
disposal. The conditions for any discharge to the sewer will be set out in a separate
trade effluent discharge licence.
14.1.3
Standard good working practices, set out in this Section, should ensure that any
impacts due to the water discharging from the Damhead Creek 2 site would be
insignificant.
14.1.4
All water required by Damhead Creek 2 will be taken from the existing towns water
supply to the existing Damhead Creek CCGT Power Station site or from the on site
bore holes. During normal operation of Damhead Creek 2 water will only be required
on a day-to-day basis for make-up to the boiler water system discussed further below.
14.1.5
The only process effluent produced by Damhead Creek 2 in any significant quantity
will be the blowdown (see discussion later in this Section) from the two HRSG’s.
Small quantities of boiler water (boiler blowdown) will be discharged in order to avoid
the build-up of impurities in the boiler water. This discharge is virtually pure water,
containing very small quantities of various chemicals that are used to prevent
corrosion and scaling in the boiler. The boiler blowdown will be recovered and reused
in the demineralisation plant as much as achievable. The remainder will all be
discharged to the existing drainage system on the proposed Development.
14.1.6
The quality of the effluent to be discharged from Damhead Creek 2 will be monitored.
It is expected that flow, pH, suspended solids and oils and grease will be monitored.
These discharges will be controlled to limits set by the Environment Agency in
Damhead Creek 2’s Environmental (EPR) Permit. Southern Water will be consulted
concerning any discharge to the sewer as this will require a separate trade effluent
discharge licence.
14.1.7
Any areas of the Damhead Creek 2 site that are likely to be contaminated with oil will
drain to oil interceptor(s) to limit visible oil in the water. This surface water, with
waters from non-contaminated areas, will drain to the existing surface water system at
Damhead Creek 1and then into the Damhead Creek.
14.2
Introduction
14.2.1
This Section considers water use at Damhead Creek 2 and the disposal of its
aqueous effluents.
14.2.2
The supply of water for construction of Damhead Creek 2 will be the responsibility of
the construction contractor. It is expected that the water source will be the existing
towns water supply to the existing Damhead Creek CCGT Power Station site.
However, an alternative to this would be to source water from boreholes beneath the
site. This alternative is currently being investigated at the existing Damhead Creek
CCGT Power Station, and would be used to source water for on site treatment and
use
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14.2.3
The discharge of any effluents during construction, including site drainage, will be the
responsibility of the construction contractor, who will be required by ScottishPower to
reach agreement with the Environment Agency and the local sewerage undertakers,
Southern Water, with regard to the detailed methods of disposal, including obtaining
the necessary licenses / consents. Standard good working practices, set out in this
Section, should ensure that any impacts due to the water discharging from the
Damhead Creek 2 site would be insignificant.
14.2.4
At present, it is envisaged that all water required by Damhead Creek 2 will be taken
from the existing towns water supply to the existing Damhead Creek CCGT Power
Station site. During normal operation of Damhead Creek 2 water will only be required
on a day-to-day basis for make-up to the boiler water system.
14.2.5
The only process effluent produced by Damhead Creek 2 in any quantity of note will
be the blowdown from the two HRSGs. Small quantities of boiler water (boiler
blowdown) are discharged in order to avoid the build-up of impurities in the boiler
water. This discharge is virtually pure water, containing very small quantities of
various chemicals that are used to prevent corrosion and scaling in the boiler. The
boiler blowdown will be recovered and reused in the demineralisation plant as much
as achievable. The remainder will all be discharged to the existing drainage system
on the site at the existing Damhead Creek Power Station site.
14.2.6
The quality of the effluent to be discharged from Damhead Creek 2 will be monitored.
It is expected that flow, pH, suspended solids and oils and grease will be monitored.
These discharges will be controlled to limits set by the Environment Agency in
Damhead Creek 2’s Environmental (EPR) Permit. Southern Water will be consulted
concerning any discharge to the sewer as this will require a separate trade effluent
discharge licence.
14.2.7
Any areas of the Damhead Creek 2 site that are likely to be contaminated with oil will
drain to oil interceptor(s) to limit visible oil in the water. This surface water, with
waters from non-contaminated areas, will drain to the existing surface water system at
the existing Damhead Creek Power Station site and then to Damhead Creek.
14.3
14.3.1
CC3
NRM1
NRM2
Resource Use
Sustainable Water Resources and Groundwater Quality
Water Quality
NR1
NR8
Development and the Prudent Use of Natural Resources
Water Quality
CF12
June 2009
Water Supply
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14.4
14.4.1
The various aspects of the water requirement for Damhead Creek 2 have been
considered.
14.4.2
Sources of the raw water were identified, and based on the most likely source of raw
water, appropriate processing and storage methods were defined, based on the
intended uses.
14.4.3
The assessment covered all major activities and processes that will generate
aqueous effluents. These are discussed in detail later in this Section. The reason for
use and the amounts of water required have been specified and, where appropriate,
the anticipated effluent compositions established.
14.4.4
Where appropriate, discussions of the likely mitigation measures to be employed are
included to help inform the final design of Damhead Creek 2. Damhead Creek 2 will
be engineered to adhere to the standards and limits set by the Environment Agency in
Damhead Creek 2’s Environmental (EPR) Permit.
14.4.5
The significance criteria of the potential/likely impacts of Damhead Creek 2 on water
quality are defined as:
High:
Moderate:
insignificant:
Large, long-term, change to the water quality;
Small, or short-term, change to the water quality; and
No perceivable impact.
14.5
14.5.1
The existing Damhead Creek CCGT Power Station is located on the Hoo Peninsula
between the River Thames to the north and the River Medway to the south. The
River Medway is the closer of these two rivers passing about 1 km to the south of the
Damhead Creek 2 site as can be seen in Figure 1.1. Damhead Creek 2 is separated
from the Medway Estuary by the existing Kingsnorth Power Station which, unlike the
existing Damhead Creek CCGT Power Station and Damhead Creek 2 abstracts 5.6
million cubic metres of water from the River Medway for cooling purposes.
14.5.2
The nearest point of the estuary to the existing Damhead Creek CCGT Power Station
is the Damhead Creek itself. The cooling water outfall from the existing Kingsnorth
Power Station flows into Damhead Creek, along with the small quantities of aqueous
effluents which are produced from the existing Damhead Creek Power CCGT Station.
As it flows east, the Damhead Creek becomes East Hoo Creek which in turn flows
into Kethold Reach, the main channel of the Medway Estuary.
14.5.3
Watercourses in the vicinity of the existing Damhead Creek CCGT Power Station and
Damhead Creek 2 can be seen in Figure 1.1.
14.5.4
The Medway Estuary is a tidal saline water habitat subject to tidal fluctuations in level.
Water drains from the salt flats such as Stoke Saltings during the ebb tide. The
estuary experiences a wide range of temperatures with the solar heating of the tidal
flats at low tide and the ingress of cooler water from the Thames Estuary at high tide.
14.5.5
The water quality of the Medway Estuary is good with relatively low concentrations of
all trace elements, below their annual average EQS value. The likely impact of
Damhead Creek 2 is considered to be negligible on water quality.
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14.6
Potential Impacts
Construction
14.6.1
A small amount of water will be required each day for the general construction works.
At present, it is envisaged that this will be taken from the existing supply of towns
water to the existing Damhead Creek CCGT Power station.
14.6.2
Several construction activities could require the disposal of water from the Damhead
Creek 2 site, such as washing facilities and run off from hardstanding. ScottishPower
will require its construction contractors to reach agreement with the Environment
Agency and if necessary the local sewerage undertakers, Southern Water, with
regard to the detailed methods of disposal. The conditions for any discharge to the
sewer will be set out in a separate trade effluent discharge licence.
14.6.3
Should a temporary diesel storage tank be necessary on the Damhead Creek 2 site
during construction, this will be double skinned or contained within a bund for
prevention of releases to the environment and sized to hold 110 per cent of the tank’s
contents. Maintenance of construction machinery will not be allowed on the
Damhead Creek 2 site, which will help to prevent the accidental leakage of lubricating
and hydraulic fluids.
14.6.4
Construction activities may, if uncontrolled, potentially cause changes to surface
water drainage due to the creation of top soil piles.
Operation
14.6.5
At present, it is envisaged that all water required by Damhead Creek 2 will be taken
from the existing towns water supply to the existing Damhead Creek CCGT Power
Station site.
14.6.6
However, an alternative to this would be to source water from boreholes beneath the
site. This alternative is currently being investigated at the existing Damhead Creek
CCGT Power Station, and would be used to source water for on site treatment and
use
14.6.7
During normal operation of Damhead Creek 2 water will only be required on a day-today basis for make-up to the boiler water system.
14.6.8
This water must be of high purity and will be treated in the existing water treatment
plant at the exiting Damhead Creek CCGT Power Station. Together with the
3
miscellaneous minor process requirement of 5 m /day, the total quantity of water from
3
Damhead Creek's supply required by Damhead Creek 2 will be of the order of 500 m
per day.
14.6.9
The towns water from the mains supply will be stored on site in the existing towns
water storage tank at Damhead Creek Power Station. The lower portion of this tank
is dedicated to fire water storage and will supply the fire fighting system. The upper
part of the towns water tank is used to supply the water treatment plant and to supply
water for domestic purposes.
14.6.10
Demineralised water from the water treatment plant is stored in an above ground
storage tank on the existing Damhead Creek CCGT Power Station site.
14.6.11
In addition, depending on detailed design, there may be one further towns water
storage tank and one further demineralised water storage tank provided under the
contract for Damhead Creek 2.
14.6.12
At the detailed design stage of the project, consideration will be given to the
incorporation of rainwater harvesting. This rain water harvesting will reduce water
consumption from other sources, adding to the sustainability of the project.
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14.6.13
Intermittent process effluents comprise air compressor wash water and very rarely an
effluent from the closed circuit cooling system. These effluents are generated in very
small quantities and would be tinkered off site as they may contain detergents.
Effluent Discharge
14.6.14
Process effluents from Damhead Creek 2 will comprise the following:
Boiler Blowdown
3
Before flashing-off to atmosphere
456 m /day
After flashing-off to atmosphere
338 m /day
3
3
Extra Water Treatment Plant
Effluent
45 m /day
Miscellaneous Minor Process
Effluents
5 m /day
3
14.6.15
The boiler blowdown will be recovered and reused in the demineralisation plant as
much as achievable. The remainder will be discharged to the site drainage system
which ultimately discharges to the Damhead Creek.
14.6.16
The quality of the effluent from Damhead Creek 2 will be monitored. It is expected
that the following parameters will be monitored: flow, pH, suspended solids and oils
and grease.
14.6.17
These discharges will be controlled to the limits set by the Environment Agency in
Damhead Creek 2's Environmental (EPR) Permit. The conditions for any discharge to
the sewer will be set out in a separate trade effluent discharge licence.
14.6.18
The surface water from any areas of the Damhead Creek 2 site that are likely to be
contaminated with oil will drain to oil interceptor(s) to limit the oil in water content to a
level regulated by the Environmental (EPR) Permit normally with a limit of “no visible
oil” quoted (normally below 10 ppm) before discharge to the storm water drainage
system located on the proposed development site.
Boiler Water
14.6.19
The boiler water / steam / condensate system has losses from its recycled water due
to some deliberate blowdown from the boilers to maintain the correct chemical
control. The water required to make up these losses must be of high purity and must
therefore be treated in a water treatment plant.
14.6.20
Although of high purity, the feed-water entering the boilers will contain small amounts
of impurities. As the water in the boiler is evaporated the impurities become
concentrated in the boiler water system. To ensure that these impurities do not cause
corrosion or scaling of the boiler heat transfer surfaces, treatment chemicals will be
added to the boiler.
14.6.21
In addition, the concentration of the impurities is controlled by discharging some of the
boiler water, either continuously or intermittently. This water is the “boiler blowdown”.
The blowdown water is replaced by fresh, treated water added to the boiler circuit.
The boiler water will be dosed with treatment chemicals in order to control corrosion.
As the feed-water will be of high purity the quantity of blowdown discharged from the
3
boiler will be small, of the order of 456 m /day. The blowdown is discharged at boiler
temperature and pressure to the storm water drainage system where it cools prior to
release to the storm drains.
14.6.22
Some of the blowdown flashes off to steam in the boiler blowdown vessel thus
3
reducing the volume still further to about 338 m /day. A majority of this boiler
blowdown will be reused by recycling through the water treatment plant. It is virtually
pure water containing very small quantities of various corrosion and scaling
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WATER QUALITY
prevention chemicals in the boilers (for example, ammonia, phosphate and
suspended solids). Any blowdown water discharged would be treated for pH prior to
release to the surface water drainage system.
14.6.23
A typical analysis of the boiler blowdown is:
Conductivity:
pH:
Ammonia as NH3:
Phosphate as PO4:
50 S/cm
10
1 mg/l
5 mg/l
The Water Treatment Plant
14.6.24
The size of the existing water treatment plant is sufficient to provide the demineralised
boiler make up water that will be required for Damhead Creek 2. The increased flow
through the existing water treatment plant will result in a slight increase in the effluent
produced by the existing water treatment plant. This effluent is discharged to the site
drainage system in small enough quantities that it would have an insignificant
environmental impact.
Site Drainage
14.6.25
There are four drainage systems on the existing Damhead Creek Power Station site;
the surface water drainage system; the oily water drainage system; the contaminated
waste water system (i.e., water treatment plant effluent and boiler blowdown); and the
onsite sewerage system. This system will be extended as appropriate to take in the
drainage from Damhead Creek 2.
14.6.26
The surface water drainage system will drain areas of the Damhead Creek 2 site
unlikely to be contaminated with oil and discharge the water to the storm water drains
of the existing Damhead Creek Power Station. The majority of the surface water
drainage will be uncontaminated and typical of surface water run off from areas of
hardstanding and roads, nevertheless water will pass through oil interceptors to
ensure that no contaminated waters are release from the site. Damhead Creek 2 will
not lead to significant quantities of surface water run off as the drainage system will
be designed by the contractor so as to avoid this through slow release of storm
waters and the use of oil interceptors.
14.6.27
An oily waste water drainage system will drain all areas of the Damhead Creek 2 site
where oil spillages could occur. The design will incorporate oil interceptors and traps.
This will discharge with the other surface water discharge to the storm water drains.
The discharge from each oil interceptor will contain no visible oil or grease.
14.6.28
The areas liable to oil spillage are:
The oil unloading area adjacent to the lubricating oil storage tanks;
The electrical transformers (which may contain insulating oil, if so this will be
polychlorinated biphenyl (PCB) free);
The areas surrounding the bunded lubricating oil storage tanks (the bunds
themselves will not have any drainage connections); and
Any car parking areas.
14.6.29
Adequate facilities for the inspection and maintenance of oil interceptors will be
provided and the interceptors will be emptied as necessary and desludged to ensure
efficient operation. A qualified contractor will dispose of the sludge off-site.
14.6.30
The new drains will discharge to the existing site drainage system within the existing
Damhead Creek CCGT Power Station before subsequently discharging to Damhead
Creek. The existing drainage system already includes interceptors to ensure oily
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WATER QUALITY
water does not escape from the site. Where possible, swale ditches and other SUDS
drainage techniques will be incorporated into the drainage design.
14.6.31
Any sewage associated with Damhead Creek 2 will be piped via the existing sewage
network to the existing sewage treatment plant.
14.6.32
All elements of the treatment systems will be regularly monitored to ensure optimum
performance and maintenance.
Miscellaneous Discharges
14.6.33
From time to time (likely about 2 times a year) it will be necessary to wash the blades
of the air compressor section of the gas turbines to remove debris that has penetrated
the inlet air filters and become lodged on the compressor blades. This will be done at
times when the performance of the gas turbines has degraded and will depend upon
the air quality in the vicinity of Damhead Creek 2. Washing can be done in two ways:
by on-line washing where a fine spray of water is allowed to pass through the gas
turbine; or by off-line washing where the compressor blades are rotated slowly
3
through a detergent solution. In the second case approximately 15 m per CCGT unit
of waste water containing detergent will be retained on-site in a storage tank and
subsequently tankered off-site by a licensed contractor for disposal at an
appropriately licensed disposal facility.
14.6.34
Boiler flue gas side washing is not anticipated. However, during commissioning and
at infrequent intervals during the life of Damhead Creek 2 it will be necessary to
chemically clean the water side of the boiler tubes. All effluents will be tankered off
site by a licensed contractor for treatment and disposal at an appropriately licensed
disposal facility.
14.6.35
During maintenance it may be necessary to drain down the boiler, the closed circuit
cooling water system or parts of these systems. All will be discharged to the site
drainage system. The boiler water discharged will be identical to boiler blowdown and
will be high purity water containing traces of ammonia, phosphate and suspended
solids. The closed circuit cooling water will be high purity water containing small
amounts of corrosion inhibitor (probably hydrazine or nitrite/borate). During the
detailed engineering stage, consideration will be given to the storage, recovery and
reuse of these effluents to further minimise the impact of the plant.
14.6.36
Sample points will be provided on the outlet of the oil separators, and in any drains at
the Damhead Creek 2 site prior to discharge.
14.6.37
No prescribed substances as described in the Environmental Permitting (England and
Wales) Regulations 2007 are generated or used on the Damhead Creek 2 site.
14.7
Construction
14.7.1
The British Standard Code of Practice for Earthworks BS 6031:1981 contains detailed
methods that should be considered for the general control of drainage on construction
sites. Further advice is also available in the British Standard Code of Practice for
Foundations BS 8004: 1986. These will be taken into account in the design and
construction of Damhead Creek 2.
14.7.2
Mitigation measures during construction will include, as appropriate:
Any oil storage tanks to be located on an impervious base provided with bund
walls to give a containment capacity of at least 110 per cent of the tank volume.
All valves and couplings to be contained within the bunded area.
Any surface water contaminated by hydrocarbons, which are used during the
construction phase, to be passed through oil/grit interceptor(s) prior to discharge.
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Measures will be taken to ensure that no leachate or any surface water that has
the potential to be contaminated is allowed to enter directly or indirectly into any
water course, underground strata or adjoining land. These will include concrete
gullies, dewatering ponds and other similar measures.
Provisions to be made so that all existing drainage systems continue to operate.
These will include visual inspections and corrective measures as appropriate.
Water inflows to excavated areas to be minimised by the use of lining materials,
good housekeeping techniques and by the control of drainage and construction
materials in order to prevent the contamination of ground water. Site personnel
to be made aware of the potential impact on ground and surface water
associated with certain aspects of the construction works to further reduce the
incidence of accidental impacts.
Refuelling of construction vehicles and equipment to be restricted to a
designated area with properly designed fuel tanks and bunds and proper
operating procedures.
Operation
14.7.3
The Environment Agency (EA) will set limits on the quality of water that is discharged
from the Damhead Creek 2 site under the Environmental (EPR) Permit. Southern
Water will be consulted concerning any discharge to the sewer as this will require a
separate trade effluent discharge licence.
14.7.4
All aqueous process effluents will be discharged to the Damhead Creek via the
existing drainage system at Damhead Creek Power Station that would be extended to
serve the new Development and will be in accordance with EA limits already in
existence for the existing Damhead Creek CCGT Power Station. The existing
drainage system already includes interceptors to ensure oily water does not escape
from the site. No further on-site treatment will be necessary as this is effectively pure
water. This represents the best practicable environmental option for these effluents
and is consistent with the approach suggested in Chapter 2 of the EA’s PPC
combustion Sector Guidance Note V2.03.
14.7.5
The water treatment plant effluent will be monitored for pH value. If the pH is out with
the limit of 6 to 9, or outside any limit permitted by the EA, the discharge will
automatically stop until the failure is corrected.
14.7.6
The use of de-icing substances will be minimised during the winter.
14.7.7
All oil and chemical storage tanks and areas where drums are stored will be
surrounded by an impermeable bund. Single tanks will be within bunds sized to
contain 110 per cent of capacity and multiple tanks or drums will be within bunds
sized to contain 110 per cent of the capacity of the largest tank. Permanently fixed
taps, filler pipes, pumping equipment, vents and sight glasses will also be located
within the bunded area. Taps and valves will be designed to discharge downwards
and will be shut and locked in that position. Manually started electrically operated
pumps will remove surface water collected within the bund and its composition will be
verified through appropriate analysis prior to disposal.
14.7.8
unlikely to be contaminated with oil due to their location and discharge the water to
the storm water drainage system. The majority of the surface water drainage will be
uncontaminated and typical of surface water run off from paved areas or roads. The
potential for contamination is minimal and associated with areas around storage
vessels which will be appropriately bunded.
14.7.9
An oily waste water drainage system will drain all areas where oil spillages could
occur. The design will incorporate oil interceptors and traps. These will discharge
June 2009
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WATER QUALITY
with the other surface water discharge to the storm water discharge system. The
discharge from each oil interceptor will contain no visible oil or grease.
14.7.10
14.7.11
14.7.12
Damhead Creek 2 will be designed to take into account the flood risks associated with
the Damhead Creek 2 site. These are fully outlined in the Flood Risk Assessment
prepared for Damhead Creek 2, which is available in Appendix H. Mitigation
measures that would be incorporated in the design of the Damhead Creek 2 site will
include the bunding / elevation of equipment that could cause contamination to water
and all equipment at the Damhead Creek 2 site sensitive to water exposure.
14.8
14.8.1
Damhead Creek 2 will be designed and engineered to ensure that all water effluents
or discharges will be in accordance with the limits set by the Environment Agency in
the relevant Environmental (EPR) Permit for Damhead Creek 2 and, if appropriate,
Southern Water. Any contaminated material will be disposed of-site by qualified and
licensed contractors, where necessary.
14.8.2
Given the above design commitments and the low water usage of the proposed
Damhead Creek 2 plant it is considered that the plant will have no significant impact
on water quality.
14.9
14.9.1
There is a very limited scope for cumulative impacts associated with the proposed
Development given the proposed mitigation measures that will be employed by the
plant and the inherent low water usage of the plant processes.
14.9.2
Damhead Creek 2 will be designed so as to have a minimal impact on ground and
surface waters with releases to each being negligible in amount. Releases to the
Damhead Creek will be dwarfed by the cooling water return of the proposed
Kingsnorth Units 5 and 6 such that the impact of Damhead Creek would be virtually
undetectable.
14.9.3
With regard to Goodman Developments Limited Kingsnorth Business Park project,
the principal cumulative impact would be associated with surface water run off.
However as both the Development and the Kingsnorth Business Park have
incorporated storm water drainage systems that include balancing ponds, the impact
on water quality will be negligible.
14.9.4
It can be concluded there is no significant impact on water quality anticipated from
Damhead Creek 2, and as such, there are no applicable cumulative effects.
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SECTION 15
GEOLOGY, HYDROLOGY AND LAND
CONTAMINATION
SECTION 15
CONTAMINATION
15
GEOLOGY, HYDROLOGY AND LAND CONTAMINATION
15.1
Summary
15.1.1
The nature of the geology, hydrology and extent of existing land contamination
beneath the Damhead Creek 2 site is well understood through a series of
investigations, both desk-based and intrusive.
15.1.2
Phase 1 Desk Based studies and Phase 2 Intrusive Site Investigations have been
consulted / undertaken as part of this Section. The aim of the Phase 1 Desk Based
studies was to assess the potential for contaminants to be present on, in or under the
land, which may pose a threat to human health or water quality. Baseline conditions
were subsequently assessed by undertaking Phase 2 Intrusive Site Investigations.
15.1.3
Analysis of the soil beneath the Damhead Creek 2 site revealed no metal
concentrations above the relevant soil guideline values (SGVs), or phytotoxic
guideline values for plant uptake. Analysis of soils beneath Areas 2 and 3 also
revealed no concentrations above SGV or Generic Assessment Criteria (GAC) values
for human health. The soil throughout all sites is relatively neutral with pH
measurements in the range 6.6 to 8.6. Elevated levels of boron were recorded across
the Damhead Creek 2 site, with the highest measurement occurring in a sample of
made ground consisting of pulverised fuel ash. Asbestos fibres were found in 1
sample of asbestos cement, found in Area 2 of the Kingsnorth Business Park land.
Evidence of asbestos was only found in asbestos cement, and is not thought to be
widespread across the site.
15.1.4
The groundwater beneath all sites was also analysed. Concentrations of Total
Petroleum Hydrocarbons (TPH) and nickel were slightly above the UK DWS/EQS in
all samples. However, as elevated concentrations of TPH and nickel were not found
in soils from the Damhead Creek 2 site, it was concluded that the contamination was
most likely from an off-site source. In addition, the effects of dilution from the
underlying minor aquifer mean that any potential sources of contamination are
unlikely to impact significantly on controlled surface waters.
15.1.5
The EA have designated part of the Damhead Creek 2 site as Flood Zone 3a.
Developments in Flood Zone 3a are considered to be ‘at risk of flooding from rivers or
sea if flood defences are not present’. A separate Flood Risk Assessment has been
undertaken and is included in Appendix H.
15.1.6
The impact of the majority of construction works on the existing environment is
considered to be minor as all impacts will be small and of a temporary nature.
However, it is understood that there will be substantial earth moving works during
clearing of Areas 2 and 3. It is essential that a sampling regime is undertaken to
verify the movement of material and leave the ground surface suitable for its intended
future use.
15.1.7
The operation and decommissioning of Damhead Creek 2 will not involve substantial
earthworks, and therefore the impact is also considered minor and temporary.
15.1.8
The main part of the Damhead Creek 2 site as well as the proposed construction
laydown area and sub-station will be predominantly covered with buildings or areas of
hardstanding. There will be a small amount of landscaped ground but no areas of
exposed (unvegetated) soils. The potential pathways for the release of residual
contaminants will therefore be broken and the impact from residual contaminants on
future site users and controlled waters will not be significant.
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15.2
Introduction
15.2.1
This Section details the baseline geological, hydrological and hydrogeological
conditions at the Damhead Creek 2 site and outlines the current and potential
environmental impacts of Damhead Creek 2 on these resources. The Section also
details the status of the Damhead Creek 2 site in terms of ground and surface water
contamination and the risks posed to human health and controlled waters (also refer
to Section 14 of this Environmental Statement ‘Water Quality’). Where potentially
significant environmental impacts have been identified, mitigation measures are
proposed to reduce the severity of such impacts to an acceptable level.
15.3
15.3.1
CC2
Climate Change
NRM1
Sustainable Water Resources and Groundwater
NRM4
Sustainable Flood Risk Management
NRM8
Coastal Management
KTG6
Flood Risk
NR5
Pollution Impacts
NR10
Development and Flood Risk
BNE23
Contaminated Land
CF13
Tidal Flood Risk Areas
15.4
15.4.1
Phase 1 Desk Based studies and Phase 2 Intrusive Site Investigations have been
consulted / undertaken as part of this Section. The aim of the Phase 1 Desk Based
studies was to assess the potential for contaminants to be present on, in or under the
land, which may pose a threat to human health or water quality. The Desk Based
studies have been conducted with reference to the British Standard Investigation of
potentially contaminated sites (BS 10175: 2001). Baseline conditions have been
assessed by undertaking Phase 2 Intrusive Site Investigations which have been
conducted with reference to the Environmental Protection Act (1990), the
Contaminated Land Regulations CLR-11 (2006) and the Construction (Health, Safety
and Welfare) Regulations 1996, recently replaced by the Construction (Design and
Management) Regulations 2007.
15.4.2
The following sources / studies were consulted / undertaken to provide a detailed
breakdown of the underlying geology and previous uses of the Damhead Creek 2 site:
Landmark Envirocheck Report for the Damhead Creek 2 site (including historical
maps and records of land pollution);
Phase 1 Desk Based Studies
Area 1 Damhead Creek 2 : Phase I Environmental Desk Study – Damhead
Creek Power Station Phase II Development – DTS Raeburn Ltd. 2006;
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CONTAMINATION
Areas 2 and 3 Damhead Creek 2 : Phase 1 Environmental Desk Study –
Goodman Developments Limited Land (Units 2B and 3) – PB December 2008;.
Phase 2 Intrusive Site Investigations
Area 1 Damhead Creek 2 : Scottish Power Generation Ltd. Damhead Creek
Power Station, Kingsnorth, Kent, Proposed Phase II Development – Report on
Ground Investigation – Terra Tek Ltd. February 2007.;
Areas 2 and 3 Damhead Creek 2 : Environmental Assessment of Units 2B and 3
at Damhead Creek Power Station, Kingsnorth, Rochester, Kent – PB January
2009,
15.4.3
The Phase 1 and Phase 2 reports are attached to this ES at Appendix I.
15.4.4
The Phase 2 Intrusive Site Investigation by Terra Tek Ltd. focussed on land to be
developed as part of Damhead Creek 2. It was undertaken from November 2006 to
January 2007 in accordance with guidance laid down by the code of practice for site
investigations: BS 5930 (1999). Eight cable percussion boreholes were screened to a
maximum depth of 30 m below ground level (bgl) and six trial pits were excavated to a
maximum depth of 2.9 m bgl by mechanical excavator. 500 mm diameter perforated
standpipes were installed in 3 No boreholes to allow monitoring of groundwater and
ground gas. On 29 January 2007, groundwater monitoring was undertaken in all
three standpipes over one tidal cycle.
15.4.5
To assess the level of contamination across the Damhead Creek 2 site, fourteen soil
samples were taken from representative substrata from boreholes and trial pits and
submitted to a UKAS accredited laboratory for the analysis of a range of
determinands.
15.4.6
The following determinands were tested for in all 14 samples:
pH;
Metals (arsenic, boron, cadmium, chromium, copper, lead mercury, nickel,
selenium, zinc);
Total Petroleum Hydrocarbons (TPH);
Water soluble sulphate; and
Asbestos.
15.4.7
The level of contamination in the soil samples which were analysed has been
assessed with reference to the Contaminated Land Exposure Assessment (CLEA)
human health risk assessment modelling programme. An end use category of
commercial/industrial was chosen and appropriate guideline values were generated to
determine the potential of any contamination found causing harm to human health
(future site users). Where values were not available through CLEA, relevant soil
guideline values (SGVs) derived by the EA were selected.
15.4.8
31 samples of made ground / soil were analysed for soluble sulphate (SO4 in a 2:1
water / soil extract).
15.4.9
Three samples of groundwater were analysed for a suite of determinands including:
Metals (arsenic, cadmium, chromium, copper, lead, mercury, selenium, zinc,
nickel);
Phenol;
Ammoniacal nitrogen;
Total cyanide;
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pH;
TPH; and
Polycyclic Aromatic Hydrocarbons (PAH) speciated as: naphthalene,
acenapthylene, acenapthene, fluorine, phenanthrene, anthracene, fluroanthene,
pyrene, benz(a)anthracene, chrysene, benzo(b/k)fluoranthene, benzo(a)pyrene,
indeno123cd)pyrene, dibenzo(ah)anthracene, benzo(ghi)perylene.
15.4.10
To assess the risk of contaminants having a negative impact on sensitive receptors
(ie controlled waters), levels of determinands recorded in groundwater samples were
assessed against UK drinking water standards (DWS) or EA Environmental Quality
Standards (EQS).
15.4.11
The migration of ground gas is commonly associated with landfill sites or large
quantities of made ground. However, assessing ground gas composition and flow
rates was outside the remit of the original report. It was recommended in the Phase 2
Intrusive Site Investigation that some ground gas monitoring and a ground gas risk
assessment may be required prior to construction, and therefore the need, or
otherwise, for any assessments will be determined prior to the start of construction.
15.4.12
The Phase 2 Intrusive Site Investigation undertaken by PB Ltd. focussed on Areas 2
and 3 of the Damhead Creek 2 site. The investigation was undertaken between the
17 and 28 November 2008 in accordance with BS10175: 2001 (‘Investigation of
Potentially Contaminated Sites’). The site investigation comprised the excavation of
31 trial pits to a maximum depth of 4.7 m bgl via mechanical excavator and the
installation of seven boreholes to a maximum depth of 15.5 m bgl using a Pioneer
Rig. All seven boreholes were installed with 50 mm standpipes for gas and
groundwater monitoring. Monitoring was undertaken on 2 occasions in all boreholes.
15.4.13
To assess levels of contamination across Areas 2 and 3, a total of 99 soils samples
(from boreholes and trial pits) were submitted to a UKAS accredited laboratory for the
analysis of the following analytical suite:
Metals and Metalloids (Arsenic, Cadmium, Chromium, Copper, Lead, mercury,
Nickel, Selenium, Zinc, Boron);
pH;
Total sulphate;
Total Cyanide;
Polycyclic Aromatic Hydrocarbons (PAH); and
Total petroleum Hydrocarbons (TPH).
15.4.14
In addition, 17 shallow soil samples and 1 sample of asbestos cement were submitted
for analysis of asbestos fibres on a presence or absence basis and 18 samples were
analysed for Total Organic Carbon (TOC) concentration.
15.4.15
The levels of contamination in the soil samples analysed have been assessed with
reference to the Contaminated Land Exposure Assessment (CLEA) human health risk
assessment modelling programme. An end use category of commercial/industrial
was chosen and appropriate guideline values were generated to determine the
potential of any contamination which was found causing harm to human health (future
site users). Where values were not available through CLEA, relevant soil guideline
values (SGVs) derived by the EA were selected.
15.4.16
A total of 18 soil samples were subject to leachate preparation and a total of twelve
groundwater samples were submitted for laboratory analysis. All lechate preparations
and groundwater samples were analysed for the following suite of determinands:
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CONTAMINATION
Metals and Metalloids (Arsenic, Cadmium, Chromium, Copper, Lead, mercury,
Nickel, Selenium, Zinc, Boron);
pH;
Sulphate;
Total Cyanide;
Sulphide;
Speciated PAH; and
TPH (C6-C40)
15.4.17
Concentrations of determinands in groundwater and leachates were compared
against several screening criteria, including EA Environmental Quality Standards
(EQS), EA Lowest Effect Concentration (LEC) (as a standard for PAH), UK Drinking
Water Standards, World Health Organisation (WHO) guideline values and Dutch
institute and human toxicology data values.
15.4.18
Standpipes were installed in all seven boreholes (in sands and gravels) for monitoring
of gas and groundwater, on 2 separate occasions.
15.4.19
Significance of any impacts have been assessed with relevance to sensitivity of the
end users and underlying ground conditions and the magnitude of the impact.
15.4.20
Significance criteria for contamination risks posed to human health have been set as
follows: Where chemical testing from boreholes has proved that levels of
contaminants are below guideline values for the specified end use criteria of
commercial / industrial, there are deemed to be no potential impacts on human
health. Where chemical contaminants have been identified above relevant soil
guideline values in limited locations or the concentrations only mildly exceed soil
guideline values, there is deemed to be a moderately significant impact on human
health of future site users. Where several contaminants exceed relevant soil
guideline values by large amounts, there is deemed to be a significant impact on
human health of future site users. Where significant or moderately significant
environmental impacts have been identified, appropriate mitigation measures are
suggested.
15.4.21
In addition, the following criteria have been used when assessing the potential impact
on underlying geology and soils:
15.4.22
Significant impacts are deemed to be impacts on areas of land of national or
international importance e.g. designated geological sites and neighbouring land uses,
highly sensitive to the type of development proposed such as grade 1 agricultural
land. Moderate impacts are deemed as those which are on areas of land of local
importance, such as important farming land especially neighbouring land highly
sensitive to the type of development proposed. Negligible impacts are those which
are deemed to be on areas of land of no more than very local significance or not
sensitive to the type of development proposed.
15.5
Damhead Creek 2 History
15.5.1
Historical maps and archaeological records indicate that between 1870 and the
present day, the only form of development on the Damhead Creek 2 site was a naval
installation which occupied the site between 1912 and 1920.
15.5.2
Maps from 1870 to 1900 show the Damhead Creek 2 site was divided into three
separate fields, possibly separated by surface water features. By 1971, all
watercourses have been removed and the Damhead Creek 2 site is shown as one
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CONTAMINATION
individual field. Maps from 1971 also show the development of the existing
Kingsnorth Coal Fired Power Station approximately 500 m to the south and an oil
refinery approximately 100 m to the north west of the Damhead Creek 2 site, although
this was removed in the 1990’s.
15.5.3
Historical maps show that Area 2 of the Damhead Creek 2 site has been used as a
storage area for fuel tanks from 1914 until the tanks were removed and
decommissioned in the 1980’s. Area 3 has remained totally undeveloped throughout
the past, although it has been in-filled with dredging materials, Pulverised Fuel Ash
(PFA) and other inert wastes in the 1960’s. Around this time, several ponds were
also constructed on the site to suppress dust from the dumping of PFA.
15.5.4
Information on the potential for land contamination at the Damhead Creek 2 site has
been obtained through a review of historical maps, as well as Phase 1 Desk Based
studies (DTS Raeburn, 2006; PB 2008) and Phase 2 Intrusive Site Investigations
(Terra Tek Ltd., 2007; PB 2009). The main potential sources of contamination on the
Damhead Creek 2 site are considered to be from off site sources, as the Damhead
Creek 2 site has harboured limited development in the past. Potential off-site sources
of contamination include the existing Kingsnorth Power Station, approximately 500 m
south east of the Damhead Creek 2 site, the existing Damhead Creek CCGT Power
Station, adjacent to the eastern boundary of the Damhead Creek 2 site and an oil
refinery, previously located approximately 100 m northeast of the Damhead Creek 2
site. Due to the type of industry involved, the most likely forms of contamination from
these sources are considered to be Total Petroleum Hydrocarbons (TPH), Polycyclic
Aromatic Hydrocarbons (PAH) and acids.
15.5.5
Potential on-site sources of contamination at Area 3 are from pulverised fuel ash, inert
wastes and sediments which were used for infilling the land in the 1960’s. Potential
on-site sources of contamination at Area 2 are considered to be hydrocarbons (PAH,
TPH) from fuel tanks which were stored on the site for approximately 70 years.
Potential off-site migration of contamination is from the same sources as for the
15.5.6
A Landmark Envirocheck Report has also shown the presence of four historical
landfill sites between 83 – 584 m from the Damhead Creek 2 site, although details
relating to the type of waste accepted and dates of operation are not available. There
are five entries relating to licensed waste management facilities between 559 – 686 m
from the Damhead Creek 2 site. One of these licenses has now been surrendered
and there are no details relating to the other four.
15.5.7
The Landmark Envirocheck Report also shows one entry relating to a registered
landfill site at 282 m from the Damhead Creek 2 site which was permitted to accept a
large amount (equal to or greater than 75 000 and less than 250 000 tonnes) of
hardcore, excavated natural materials and pulverised fuel ash per year. However the
licence was cancelled in 1978 and not renewed. It is unknown whether this is Area 3
of the Damhead Creek 2 site.
15.5.8
Although none of the above licenses remain active, there is still the potential for off
site migration of leachate or ground gas from buried waste on to the Damhead Creek
2 site.
Geology and Soils
15.5.9
Reference to British Geological Survey (BGS) 1:50 000 scale solid and drift Geology
map (sheet 272; Chatham) indicates that the Damhead Creek 2 site and much of the
surrounding area, is underlain by drift deposits of marine and estuarine alluvium and
River Terrace Gravels (west and north of the Damhead Creek 2 site). Solid geology
consists of London Clay (up to 137 m thick) overlying Upper Chalk base rock.
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15.5.10
The surrounding areas of Kingsnorth and Hoo St. Werburgh are of a varying land
quality, as shown by DEFRA Agricultural Land Classification (ALC) maps. The sites
are classified as ‘urban’ in character, and as such there are no areas of fertile soil or
high quality agricultural land in the immediate vicinity of the Damhead Creek 2.
However, approximately 500 m north of the Damhead Creek 2 site, is a large area
(approximately 355 000 ha) of high quality agricultural land (Grade 1).
Phase 2 Intrusive Site Investigation – Terra Tek Ltd. 2007
15.5.11
15.5.12
The Phase 2 Intrusive Site Investigation undertaken on the Damhead Creek 2 site
(Terra Tek Ltd. 2007) identified 9 distinct soil types (lithological units) across the site.
These are as follows:
i.
Made Ground. This was discovered in the far west of the Damhead Creek 2
site at depths between 0.25 and 1.8 m bgl. Made ground was generally
described as “sandy gravelly clay with broken brick and concrete”, although
pulverized fuel ash (PFA) and concrete obstructions were also discovered in
the north and east of the site.
ii.
Sandy Clay or Sandy Gravelly Clay. Clay was generally firm and stiff,
although softer material was also present in some borehole locations,
particularly in the east of the site. This strata was encountered at depths
ranging from 1.45 to 5.20 m bgl.
iii.
Clayey or Silty Sand and Gravel. Associated with alluviual deposits
originating from River Medway / Damhead Creek. Described as “extremely
variable – ranging from an almost clean sandy gravel, to clayey or silty
gravelly sand. Occasional cobbles present”. Soil generally loose and
medium dense. Encountered to depths ranging from 4.20 to 6.10 m bgl
across the site.
iv.
Clay and Sandy Clay. Consistency of clay ranged from firm to very stiff
although soft pockets occasionally noted. Encountered to depths ranging
between 6.0 and 9.50 m bgl across the site
v.
Clayey or Silty Sand and Gravel. Classified as medium dense to dense.
Encountered to depths ranging from 8.00 to 10.65 m bgl. Encountered
mainly in the west of the site
vi.
Clay and Sandy Clay. Classified as firm to very stiff encountered to depths
ranging from 13 to 6.2 m bgl. Mainly encountered in the east of the site
vii.
Clayey or Silty Sand. Classified as medium dense to dense containing
pieces of wood and other organic matter. Encountered to depths ranging
from 15.0 to 23.0 m bgl across the site
viii.
Clay and Sandy Clay. Classified as firm to stiff containing shells.
Encountered to depths ranging from 17.2 to 24.9 m bgl across the site.
ix.
Clayey or Silty Sand. Classified as medium dense to dense containing
bands of clay and small pieces of wood. The majority of boreholes (BH1,
BH2, BH3, BH6, BH7 and BH8) were completed in this stratum at depths
between 20.45 and 30.0 m bgl.
All levels of contaminants and SGVs are published in the Phase 2 Intrusive Site
Investigation (Terra Tek Ltd. 2007) which has been included as Appendix I of this ES.
However, the following provides a summary of the results:
No metal concentrations were recorded above the relevant SGVs.
There is currently no recognised British guidance for the assessment of risk
posed by petroleum hydrocarbons, although a Tier 1 threshold of 50 mg/kg
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CONTAMINATION
(Dutch guideline value) was used in the human health risk assessment in the
current study. Concentrations of Total Petroleum Hydrocarbons (TPH) were
measured between <1 mg/kg (below limit of detection) to 50 mg/kg. Only one
sample had a concentration of 50 mg/kg and no samples exceeded the Dutch
threshold value. The mean of the 95th percentile was calculated at 16 mg/kg.
No asbestos fibres were found in any of the samples.
Elevated levels of boron were recorded across the Damhead Creek 2 site with
the highest concentrations recorded in Pulverized Fuel Ash. Statistical analysis
using the mean of the 95th percentile shows that the sample is an outlier and
therefore considered a hotspot. Removing the sample and repeating the test
shows that the 95th percentile of the mean falls below the threshold value with
no outliers.
The Sludge (Use In Agriculture) Regulations 1998 (SI1263) have been used to
assess the potential for phytotoxic uptake of nickel, copper and zinc by plants.
No concentrations exceeded the guideline values.
pH ranged from 6.6 to 8.6, suggesting that relatively neutral conditions prevail
across the Damhead Creek 2 site.
Phase 2 Intrusive Site Investigation – PB Ltd. 2009
15.5.13
The Intrusive Site investigation undertaken by PB Ltd. (2009) identified two main
lithological units in Area 3 and two main Lithological Units in Area 2 of the Damhead
Creek 2 site. These can be summarised as follows:
Area 2
15.5.14
Made Ground was encountered within all trial pits and boreholes across Area 2,
ranging in thickness from 0.5 m to 3.2 m and typically comprising:
Surface cover of gravel and moss with sparse ruderal vegetation, overlying orangebrown moderately clayey gravelly sand. Gravel, cobbles and boulders of aerated
blocks with coarse sand and orange – brown / grey-brown sandy clay with a minor
gravel component of flint and occasional anthropogenic inclusions comprising red
brick, clay tile and concrete.
15.5.15
A slightly different composition of made ground was noted in trial pits TP109 and
TP130, located on the grass verge close to Area 1. Made ground in this area typically
comprised:
Dark brown, slightly clayey sand and gravel. This was underlain by a gravelly, silty,
clayey sand with inclusions of various anthropogenic materials including rubber,
metal, brick and glass.
15.5.16
Natural Ground was found across Area 2 comprising an orange-brown coarse sand
and gravel typically associated with river Terrace Deposits. The sands and gravels
were interbedded with firm to stiff sand clay.
15.5.17
London Clay (stiff to very stiff dark blue-grey clay) was found underlying river terrace
deposits across Area 2.
Area 3
15.5.18
Made Ground was encountered in all trial pits and boreholes across the site in Area
3, with thickness ranging from 0.08 m to 7.4 m
15.5.19
Across the western and central areas of Area 3, made ground consisted of PFA and
aerated blocks, underlain by more PFA. PFA was frequently underlain by black
decaying grass and associated dark brown silty sand topsoil.
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15.5.20
Across the eastern area of Area 3, made ground typically consisted of long grass
underlain by brown silty sand topsoil.
15.5.21
Natural Ground in the western area of Area 3 was very soft dark blue-grey clay with
pockets of plant material. This was underlain by orange-brown coarse sand and
gravel (River Terrace Deposits). Underlying River Terrace Deposits were strata
associated with London Clay, as described for Area 2.
15.5.22
In the eastern area of Area 3, Natural ground consisted of River Terrace deposits
underlain by London Clay deposits.
15.5.23
The alluvium deposits associated with the River Medway and Damhead Creek are of
a younger age than the London Clay and Upper Chalk which were encountered.
Historical maps suggest that part of the Damhead Creek 2 site was reclaimed as
areas of salt marsh on the River banks dried out. This would account for the alluvium
deposits. During intrusive investigations, alluvium deposits were recovered in the
majority of boreholes and trial pit locations across Area 1 of the Damhead Creek 2
site. The alluvium was generally described as sandy clay, sandy gravelly clay or
clayey silty sand and gravel.
15.5.24
The London Clay deposits underlie much of the south east of England and form the
solid geology of the area. It is possible that the deeper, stiffer clays are associated
with these deposits. Their full thickness beneath the Damhead Creek 2 site has not
been proved by intrusive ground investigation but deposits are known to be up to
137 m thick, based on BGS sheet 272. The clay was deposited in the Eocene period
and is characterised by blue-grey stiff/hard clay with calcium sulphate crystals,
although areas of more silty deposits are also present where the clay has been
weathered.
15.5.25
Underlying the London clay are Upper Chalk deposits. Upper Chalk deposits underlie
much of the Medway area. It is of cretaceous age and described as white variable
chalk containing occasional flints. Chalk deposits have been recorded up to 91 m in
thickness by BGS boreholes. Chalk was not encountered during the intrusive ground
investigation.
15.5.26
There are no statutory or non-statutory sites designated for their geological
importance in the vicinity of the Damhead Creek 2 site, nor are there any features of
geomorphological interest within the boundary of the Damhead Creek 2 site or
surrounding area.
15.5.27
All levels of contaminants and SGVs are published in the Phase 2 Intrusive Site
Investigation (PB, 2009), which has been included in Appendix I of this ES. However,
the following provides a summary of the results:
15.5.28
Visual and olfactory evidence of hydrocarbon contamination were found at the
following locations during the Phase 2 Intrusive Site Investigation:
Area 2
TP 101 – 2.45 – 2.9m bgl
TP 103 – 1.18 – 3.6m bgl
TP104 0.97 m bgl and 1.05 – 2.3 m bgl
TP 106 0.35 – 3.5 m bgl
TP130 0.23 – 1.7 m bgl
TP131 2.0-2.2 m bgl
BH203 0.5 – 0.8 m bgl and 4.1 – 6.0 m bgl
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CONTAMINATION
BH206 1.5 – 3.2 m bgl
Area 3
BH201 5.0 – 6.7 m bgl
BH202 6.5 – 7.4 m bgl
BH207 3.2 – 4.8 m bgl
TP118 2.5 – 4.3 m bgl
TP121 1.7 – 1.8 m bgl
BH207 3.4 – 4.8 m bgl
15.5.29
Although several locations had visual and olfactory evidence of contamination, no soil
samples across the site (PFA, Made Ground, or River Terrace Deposits) were in
exceedance of any SGV’s for metalloids, PAH, TPH. One soil sample out of the 17
analysed for asbestos returned a positive identification of chrysolite asbestos. This
was a piece of suspected asbestos cement retrieved from TP 130 at 15 m bgl.
Hydrogeology
15.5.30
The alluvium deposits underlying the Damhead Creek 2 site are described as a minor
aquifer. Minor aquifers are described as fractured or potentially fractured rocks,
which do not have a high primary permeability, or other formations of variable
permeability including unconsolidated deposits. Although not producing large
quantities of water for abstraction, they are important for local supplies and in
supplying base flow to rivers.
15.5.31
London Clay underlying the alluvial deposits is classified as a non-aquifer which is
negligibly permeable. Non-aquifers are described as formations which are generally
regarded as containing insignificant quantities of groundwater and are therefore
unimportant for abstraction or supplying base flow to rivers.
15.5.32
The Upper Chalk deposits are classified as a major aquifer. However, the chalk is
overlain by a significant depth of London Clay and therefore is not considered to be at
risk from percolation of any pollutants which may potentially occur as a result of any
development on the Damhead Creek 2 site.
15.5.33
Soil vulnerability of the Damhead Creek 2 site is classed as having a negligible
leaching potential. However, groundwater flow may still take place and needs to be
taken into account when assessing the risk associated with persistent pollutants
occurring as a result of Damhead Creek 2 development.
15.5.34
The Envirocheck report indicates that there are no water abstraction licenses located
within 250 m of the Damhead Creek 2 development, although there are four licenses
between 250 and 1000 m from the Damhead Creek 2 site. Two of these relate to the
existing Damhead Creek CCGT Power Station and allow the abstraction of
groundwater from a single source. Total licensed surface water abstraction from
Medway Catchment is 153 204 131 m 3/yr. Total licensed groundwater abstraction is
90 958 515 m3/yr (PB Power 2007).
15.5.35
There are no Nitrate Vulnerable Zones (NVZ) or Nitrate Sensitive Areas (NSA) within
1 km of the Damhead Creek 2 site and the Damhead Creek 2 site does not lie within
a Source Protection Zone (SPZ).
15.5.36
Groundwater was observed under Area 1 in the Phase 2 intrusive ground
investigation (Terra Tek, 2008) at depths ranging from 3.0 to 9.5 m bgl, from where
the levels rose to between 1.45 m and 4.70 m bgl over a period of 20 minutes.
Groundwater was observed under Areas 2 and 3 during the Phase 2 Intrusive Site
Investigation (PB. 2009) at depths between 1.62 – 7.05 m bgl during two monitoring
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CONTAMINATION
rounds. The relatively high groundwater levels are likely to be due to the close
proximity of the Damhead Creek 2 site to Damhead Creek, and as such, the two are
most likely in hydraulic continuity.
Standpipes recorded a tidal variation of
approximately 0.10 m in the groundwater.
Groundwater Contamination
15.5.37
Concentrations of Total Petroleum Hydrocarbons (TPH) and nickel exceeded the UK
DWS/EQS in all samples of groundwater sampled in the Damhead Creek 2 site.
However, as elevated concentrations of TPH and nickel were not found in soils from
the Damhead Creek 2 site, the studies / reports in Appendix I conclude that this
contamination was most likely from an off-site source.
15.5.38
Four samples submitted for leachate analysis returned elevated concentrations as
follows:
1 Exceedance of Chromium in TP124 at 0.50 m bgl on Area 3
3 Exceedances of Selenium in TP110 at 0.60 m bgl, TP112 at 0.40 m bgl and
TP124 at 0.50 m bgl on Area 3.
15.5.39
A number of exceedances of relevant screening criteria were found in the
groundwater samples. These are as follows:
7 exceedances of Copper and Chromium in BH 201 (2 exceedances), 204 (2
exceedances), 207 (2 exceedances) and BH202 (1 exceedance), all in Area 3.
1 exceedance of Mercury in BH204 in Area 3.
2 exceedances of Nickel in BH206 in Area 2.
4 exceedances of TPH, 3 in the aliphatic band and one in the aromatic band in
Area 2.
Hydrology
15.5.40
Historical maps (from 1897) have suggested that there were a number of ditches
dissecting the Damhead Creek 2 site into three separate fields. However, by 1971
these appear on the map as much smaller field boundaries, suggesting that the
ditches have become in-filled or have been removed. By 1999, no evidence of the
field boundaries remains.
15.5.41
Damhead Creek is located approximately 100 m south-east of the Damhead Creek 2
site at its closest point. It is a tributary of the tidal River Medway and flows from the
eastern boundary of the existing Kingsnorth Power Station, past the southern
boundary of the Damhead Creek 2 site and the existing Damhead Creek CCGT
Power Station before turning northeast and then south-east and entering the River
Medway.
15.5.42
The River Medway is located approximately 1 km to the south of the Damhead Creek
2 site at its closest point. It is also tidal at this point and approximately 1 km wide.
The Medway Estuary is a tidal saline water habitat subject to tidal fluctuations in level.
Water drains from the salt flats such as Stoke Saltings during the ebb tide. The
estuary experiences a wide range of temperatures with the solar heating of the tidal
flats at low tide and the ingress of cooler water from the Thames Estuary at high tide.
15.5.43
Damhead Creek has been assessed as part of the Water Framework Directive (WFD)
as ‘at risk’ from diffuse source pollution, but ‘not at risk’ from point source pollution
and ‘probably not at risk’ from water abstraction, physical or morphological alteration
or introduction of alien species. As part of the WFD, the River Medway has been
classified as a ‘transitional waterway’ (transitional environment between the land and
the sea and from fresh to saline water) and was deemed ‘at risk’ from point and
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CONTAMINATION
diffuse source pollution, and ‘probably at risk’ from water abstraction and flow
regulation, physical or morphological alteration and introduction of alien species.
15.5.44
There are two ponds located on Area 3 which were used for dust suppression during
previous dumping of PFA. These are man made ponds and are not recharged by any
streams or other surface waters. There are also two ponds just outside of the eastern
boundary of the Damhead Creek 2 site. These ponds were created in 1999 / 2000 as
alternative habitat for reptiles following the development of the existing Damhead
Creek CCGT Power Station. There is no flow of surface water into these ponds.
Flooding
15.5.45
The EA has designated part of the Damhead Creek 2 site as Flood Zone 3a.
Developments in Flood Zone 3a are considered to be ‘at risk of flooding from rivers or
sea if flood defences are not present’. EA maintained sea defences are present to
the south and east of the Damhead Creek 2 site with elevations of 5.7 m AOD or
greater. These defences provide protection against tidal flooding for a return period
of almost 1 in 1000 years. Secondary earth bunds also provide the Damhead Creek
2 site with a similar level of protection therefore the risk of tidal flooding is low.
15.5.46
The Damhead Creek 2 site is not considered to be at risk from fluvial flooding and
existing drainage ditches and earth bunds provide sufficient protection from surface
water run-off from the adjacent Kingsnorth Units 1 – 4 and Kingsnorth Industrial
Estate, and the proposed Kingsnorth Units 5 and 6 and Kingsnorth Business Park
and surrounding land.
15.5.47
The main source of flood risk for the Damhead Creek 2 site is from surface water runoff generated at the Damhead Creek 2 site. The existing Damhead Creek CCGT
Power Station includes a balancing pond for surface water storage. Damhead Creek
2 would most likely connect into this balancing pond. The discharge rate from the
pond into Damhead Creek is controlled to prevent flooding. Boundary ditches located
to the south and east of the existing Damhead Creek CCGT Power Station site
provide further site drainage measures.
15.5.48
The Damhead Creek 2 site has not been subject to flooding since the construction of
the existing Damhead Creek CCGT Power Station. A separate Flood Risk
Assessment (FRA) has been undertaken and is available in Appendix H.
Receptors
15.5.49
Critical receptors for potential contamination originating from the Damhead Creek 2
site include the following:
Construction workers;
Future site users (operational staff at Damhead Creek 2); and
Groundwater and surface water.
15.5.50
The main sensitive ecological receptor in the vicinity of the Damhead Creek 2 site is
considered to be the Medway Estuary and Marshes, a site of special scientific interest
(SSSI), Special Protection Area (SPA) and RAMSAR site, approximately 100 m to the
south-east of the Damhead Creek 2 site at its closest point.
15.6
Potential Impacts
Construction
Human Health
15.6.1
Potential pollutant pathways during construction have been identified within the
contamination risk assessment carried out in the Phase 2 Intrusive Site
Investigations.
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CONTAMINATION
15.6.2
There is the possibility that site workers could come into contact with low levels of
contamination in soils or groundwater, (particularly from elevated levels of boron on
the Damhead Creek 2 site). Overall, only one sample of soil returned a level of boron
above the relevant SGV and one sample of soil returned a TPH concentration equal
to the limit of Dutch screening values. However, the mean of the 95th percentile was
well below the threshold in both cases. The risk to construction workers is therefore
considered minor as they will potentially experience only short term exposure to very
low levels of contaminants.
However, all construction workers should wear
appropriate PPE at all times when on site including overalls, gloves, strong footwear,
and dust masks where appropriate. In areas where asbestos is expected, more
stringent PPE may be required, such as specialist respiratory equipment and
disposable suits.
15.6.3
No asbestos fibres or elevated concentrations of TPH or PAH were recorded in any of
the soil samples recovered across Areas 1 and 2 of the Damhead Creek 2 site.
However, one sample of chryosite asbestos cement was discovered in Area 3. It is
suggested that when working in this area, full PPE including disposable suits and face
masks should be worn to limit the risk of inhalation of asbestos fibres. All asbestos
containing material should be dealt with appropriately and in accordance with
legislation, including being removed by a licensed contractor.
Underlying Geology
15.6.4
The proposed construction of Damhead Creek 2 will result in the permanent loss of
approximately 23.8 ha of made ground / alluvium / river terrace deposits which has
been set aside as an area for future development under the Medway Local Plan.
There will be no impact on the underlying chalk aquifer due to the thickness of
London Clay deposits underlying the sites. There are no geologically designated
sites or fertile soils within the immediate vicinity of the Damhead Creek 2 site.
Therefore, the impacts on the surrounding soils, geology and geomorphology are
expected to be insignificant.
15.6.5
The impacts on soils and geology are considered insignificant, as any impacts would
be mainly confined to made ground and river deposits just below the subsurface. If
any impacts did occur, they would be confined to localised, temporary erosion and
compaction impacts caused by earthworks and vehicular movements. Impacts on
near-surface soils would be within the construction footprint, laydown areas and
access roads.
Surface and Groundwater
15.6.6
No samples of surface water were collected from Damhead Creek during the
investigations. However, as the levels of contaminants were found to be low in the
soils, the risk of construction activities creating pathways between the soil beneath
the Damhead Creek 2 site and surface water is considered low.
15.6.7
During the construction period, the disturbance of made ground will enable greater
percolation of rainfall across the Damhead Creek 2 site and may enable the
mobilisation of low levels of contaminants. However, due to the very small amounts
of contamination present within the made ground and the presence of the attenuating
alluvial deposits underlying the made ground, the impact of this is considered to be
insignificant as it is anticipated that there will be very little leaching of any
contaminants to surface water or groundwater.
15.6.8
Precipitation draining across exposed areas of the Damhead Creek 2 site could result
in sediment within surface run-off because of ground disturbance. However, the
impact of this is considered to be minor providing excavations are sheeted during
heavy rainfall events.
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CONTAMINATION
15.6.9
The upper chalk underlying the Damhead Creek 2 site at significant depth is
considered a major aquifer. However, due to the significant depth of overlying
London Clay (non aquifer) the impact of the proposed works on the chalk aquifer is
considered to be insignificant.
15.6.10
Groundwater was recorded beneath the Damhead Creek 2 site at depths of between
3.54 to 5.84 m bgl and beneath Areas 2 and 3 at depths of between 1.62 – 7.05 m
bgl. Groundwater lowering via a pump system (dewatering) and subsequent disposal
of the water removed may therefore be required in some areas of the Damhead
Creek 2 site during earthworks. Perched waters (i.e. small pockets of water lying
above the water table) or groundwater from the dewatering operations will not be
discharged to surface water, foul or surface water drains without the appropriate
consents from the local sewerage company and/or the EA. This disposal will be the
responsibility of the contractor. If necessary this water will be tankered off-site for
disposal at a suitable facility.
15.6.11
The detected elevated levels of TPH, Nickel, Chromium, copper and Selenium, in the
groundwater is likely to have arisen as a result of off-site contamination and therefore
the Damhead Creek 2 site works are unlikely to create additional pathways between
contaminants and sensitive receptors (e.g. Damhead Creek). It was however advised
in the Phase 2 Intrusive Site Investigations that further sampling and testing of
groundwater is conducted to accurately measure groundwater conditions from fresh
samples. The need and extent of any further sampling will be determined and
undertaken prior to any construction works on site.
15.6.12
There is the potential for spills / leakage of oil associated with construction machinery
and vehicles. The storage of fuel, equipment and construction materials will be
designed so as to minimise the risk of soil contamination or water pollution, for
example through the use of bunds, drip trays and oil interceptors in accordance with
Environment Agency guidelines, Planning Policy Guidance Note (PPG) 10 and The
Control of Pollution (Oil Storage) (England) Regulations 2001.
Operation
15.6.13
The Damhead Creek 2 site will be predominantly covered with buildings or areas of
hardstanding. A small area of the site will be landscaped but no areas of exposed
(unvegetated) soils will be present. As a result the potential pathway between any
ground contaminants and site users will be broken. It is therefore considered that the
potential for direct (dermal, oral or inhalation) contact with any remaining
contaminants present beneath the surface is insignificant for future site operatives.
15.6.14
No concentrations of any determinands were recorded above phytotoxic levels (levels
above which flora would be at risk from damage) and therefore risk to sensitive
receptors (i.e. important floral species) is also considered insignificant.
15.6.15
All areas of the Damhead Creek 2 site will drain to either a sewer or Damhead Creek
via a drainage system incorporating oil interceptors and silt traps. This will almost
certainly eliminate the potential of the percolation of pollutants, into groundwater or
surface water following rainfall. The impact is therefore considered insignificant.
15.6.16
Only relatively small quantities of potentially hazardous substances will be stored and
used at the Damhead Creek 2 site. These substances include transformer and
lubricating oils as well as de-scaling chemicals used in the boiler. All oils and
chemicals will be stored in appropriate bunds and / or storage areas in accordance
with all relevant guidance and legislation as detailed above.
Decommissioning
15.6.17
The impacts on geology, soils, surface and ground water quality during
decommissioning will be temporary and minor in nature and would be similar to those
described above for construction.
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CONTAMINATION
15.6.18
The foundations may be left in the ground after decommissioning of the Damhead
Creek 2 site. It is common for concrete foundations to remain in the ground for many
years. The proposed foundations will consist of an appropriate concrete to prevent
corrosive attack from contaminants and prevent leaching, and thus no effect on the
local environment is envisaged and the impact will be insignificant.
15.6.19
Upon decommissioning, the ground will be reinstated back to its original state with
topsoil and vegetation cover where appropriate.
15.7
Construction
15.7.1
During construction, all spoil will be stockpiled away from surface water and freshly
excavated areas. A minimum distance of stockpiles from surface water will be agreed
with the EA and construction contractors. Data from Phase 2 Intrusive Site
Investigations (Terra Tek Ltd. 2007; PB Ltd. 2009) suggests that the sites are not
heavily contaminated. Therefore if there is any run-off from stockpiles this is likely to
be uncontaminated. However, to prevent suspended sediments entering surface
water, exposed areas of soil will be kept to a minimum and any exposed soil will not
be left uncovered for long periods of time. In addition, surface run-off will be pumped
or drained off the site via a silt trap, minimising any potential impacts.
15.7.2
In order to limit disturbance and mixing between soils, groundwater and surface water
during construction, the construction area will be delineated and no vehicle use will be
undertaken outside the working boundary, other than on hardstanding or access
roads. In order to further limit disturbance, any additional site access roads required
will be constructed prior to the commencement of any excavations on the Damhead
Creek 2 site.
15.7.3
Current access roads will be used for the Damhead Creek 2 site. These roads have
been constructed with an appropriate camber and drainage system so as to manage
heavy rainfall and associated run-off. If any new access roads are required, they will
be constructed to a similar standard, so as to manage any additional run-off which
occurs.
15.7.4
Precautions will be undertaken to ensure the protection of the watercourses in the
vicinity of the Damhead Creek 2 site (River Medway and Damhead Creek). No
substance or drainage will be discharged to surface water unless agreed with the EA
and in accordance with the relevant discharge consent. In addition, pollution
prevention measures such as compliance with PPG 10 and The Control of Pollution
(Oil Storage) (England) Regulations 2001, will be used on site to prevent any
contamination of the groundwater.
15.7.5
A temporary wheel washing facility will be installed to prevent transfer of soil onto
nearby public roads.
15.7.6
Excavation and foundation construction would be conducted in a manner that will
minimise the size and duration of the excavated area.
15.7.7
Dust suppression measures, such as dowsing stockpiles with water, will minimise
dust levels on the Damhead Creek 2 site and in the surrounding environment
(minimising the potential of inhalation of contaminants). Further details are provided
in Section 10 of this ES.
15.7.8
All manual workers will be required to wear appropriate PPE during the construction
phase and strict hygiene measures will be adopted. Unsupervised man entry into
excavations will not be permitted.
15.7.9
The contractor will provide a silt trap and/or oil interceptor(s) at a location(s) agreed
with the Environment Agency to allow solids or immiscible liquids to settle/separate
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CONTAMINATION
prior to discharge. The contractor will inspect, empty and maintain any silt traps /
interceptors which are installed. A registered waste carrier will remove all sludges or
residues collected during cleaning operations off site to a suitably licensed waste
disposal facility.
15.7.10
Any pumping of water from excavations will be undertaken at such a rate using an
appropriately sized pump in order to avoid unnecessary disturbance or erosion. The
location of dewatering pipework will be carefully positioned to minimise the risk of
damage to underlying geology. The contractor will regularly inspect all dewatering
pumps, pipe work and connections.
15.7.11
The British Standard Code of Practice for Earthworks (BS 6031:1981) contains
detailed methods that would be considered for the general control of drainage on
construction sites. Further advice is also available in the British Standard Code of
Practice for Foundations BS 8004:1986. These will also be taken into account.
15.7.12
The compaction of the soils will be minimised by restricting vehicle movements to
specified routes and construction areas by segregating construction areas from other
sites. In addition, a temporary site compound will be constructed for the parking of
construction vehicles and equipment, staff vehicles, and the storage of materials.
15.7.13
Storage of fuel would be limited and secure. Temporary diesel storage tanks will be
double skinned or contained with an impermeable bund, capable of holding 110 per
cent of the tank’s contents. Oil will be stored in accordance with The Control of
Pollution (Oil Storage) (England) Regulations (2001).
15.7.14
Construction machinery will be checked regularly to prevent oil leaks or other
emissions from faulty operation. Maintenance of construction machinery will not be
allowed on the Damhead Creek 2 site, which will help to prevent the accidental
leakage of lubricating and hydraulic fluids. Refuelling will be limited to a designated
area, on an impermeable surface, at a sufficient distance away from any drains or
watercourses (this distance may need to be discussed between the EA and
contractors). Spill kits, absorbent geotextiles and absorbent sands will be available
on the Damhead Creek 2 site at all times, in accordance with The Control of Pollution
(Oil Storage) (England) Regulations (2001) and PPG 10. Any spills will be cleaned up
as soon as possible, according to the spill response plan which will be prepared for
the site, with any contaminated sands bagged up and disposed of correctly.
15.7.15
Parking of staff vehicles and equipment will only be permitted in designated areas.
15.7.16
Throughout the works, the Waste Management "Duty of Care" and the Hazardous
Waste (England and Wales) Regulations 2005 (as amended) and all other relevant
waste legislation will be strictly adhered to, including the collation of all required
paperwork (such as waste transfer notes and consignment notes) and checking of
transport and disposal contractors.
15.7.17
Spoil generated on the Damhead Creek 2 site will be stockpiled, tested for waste
acceptance criteria and geotechnical composition if necessary and removed off the
Damhead Creek 2 site by a waste contractor by appropriate means or re-used on
Damhead Creek 2 site to fill excavations, if permitted. The excavated spoil will be
split into two categories for handling: ‘contaminated’ and ‘uncontaminated’. This
distinction will be determined from the results of samples taken from trial pits and
other prior investigations to show the quality and quantity of excavated material.
15.7.18
The physical division between the two categories of spoil will be made before it is
removed from the Damhead Creek 2 site. Hazardous Waste and excavated spoil and
materials that are classified as giving rise to an environmental hazard will be disposed
of at a suitably licensed waste disposal site. Vehicles carrying wastes would be
suitably licensed and sheeted / netted or appropriately covered to prevent the escape
of waste materials en route.
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CONTAMINATION
15.7.19
All works will be undertaken with reference to the Waste Management Duty of Care,
imposed by Section 34 of the Environmental Protection Act (1990) and the Hazardous
Waste (England and Wales) Regulations (2005).
15.7.20
Where spoil is not contaminated, the approach will be to adopt a disposal hierarchy,
with the first choice option being to re-use spoil on site as part of Damhead Creek 2
project wherever possible. The second choice would be to reuse spoil in other
developments taking place within the locality of the Damhead Creek 2 site, however,
it is unlikely that the majority of the spoil will be required as part of the construction
works on Damhead Creek 2 site. If these are not possible, the final choice will be for
removal of the waste spoil from the Damhead Creek 2 site for disposal by a suitably
licensed contractor.
Installation of Foundations
15.7.21
Piled foundations are likely to be necessary due to the poor soil conditions underlying
the Damhead Creek 2 site (i.e., areas of soft clay and underlying granular soils).
Further details of the recommended foundations for Damhead Creek 2 are given in
the Phase 2 site investigation report (Terra Tek ltd. 2007) which has been reproduced
in Appendix I of this ES.
Operation
15.7.22
No areas of the Damhead Creek 2 site will be accessible to the general public.
Therefore, members of the general public are not considered to be at any risk from
contaminants on the Damhead Creek 2 site and no further mitigation measures are
considered to be necessary.
15.7.23
A full Environmental Management Plan (EMP) with training will be delivered to the
operational staff of the plant to ensure that all potentially contaminating materials are
handled correctly and cleaned up effectively if any spillages take place.
15.7.24
Disposal of all waste materials will be via appropriately licensed disposal contractors.
15.8
Residual Impacts
15.8.1
All impacts on geology, hydrology and land contamination are either insignificant or
minor and temporary in nature due to the relatively uncontaminated nature of the
Development site and the mitigation measures proposed. As such the environmental
impact of the construction, operation and decommissioning of the plant will be
insignificant and there will be no residual impacts. This will be ensured by the EA
who will require as part of the plants EPR Permit that the site is returned to its
pervious or a better condition than present following decommissioning.
15.9
Cumulative Impacts
15.9.1
The environmental statements for both the Kingsnorth 5 and 6 and Kingsnorth
Business Park developments suggest that the land on which they are located are not
contaminated in any significant way. Similarly both ES documents detail means by
which contamination of the relevant sites would be controlled. Given the details
provided in these documents and the mitigation measures they propose cumulative
impacts when considered in conjunction with the Damhead Creek 2 Development are
considered likely to be minimal and insignificant.
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SECTION 16
16
16.1
Summary
16.1.1
Access to Damhead Creek 2 is afforded by a dedicated access road that leads
around the existing Kingsnorth Industrial Estate, immediately north west of the plant,
and connects with Stoke Road. Roper’s Lane connects Stoke Road to the A228
approximately 1.1 km north east of the junction for Hoo St. Werburgh and around
1.2 km south of High Halstow.
16.1.2
Should the entire of Damhead Creek 2 be built in one stage, where the construction
would take between 28 and 36 months, the construction workforce would peak at
around 1000 personnel per day. Should a two stage construction process be
undertaken, each phase would be over approximately 28 to 36 months and therefore
would increase the construction period by around three years. However, the peak onsite construction workforce would reduce to around 600 personnel per day and would
also reduce the associated traffic flows.
16.1.3
A Transport Management Plan would be agreed with the local highways officer prior
to the commencement of the construction phase to help mitigate the potential impact
of the proposed works to local and regional traffic and infrastructure. During
construction, the use of public transport and car sharing will be encouraged so as to
reduce the number of vehicles visiting site. ScottishPower would encourage its
construction contractors to provide a minibus service for construction staff.
16.1.4
In addition to staff transport movements, construction traffic will consist of civil works
traffic, mechanical works traffic and a small number of abnormal loads for
components such as the gas and steam turbine(s). Approximately 50 heavy
commercial vehicles per day will be expected on average with 100 per day at the
peak of the construction period. Vehicles bringing deliveries to site are likely to be
spread throughout the working day.
16.1.5
The exact number of abnormal loads would depend on the configuration of Damhead
Creek 2 which will only be finalised during the tendering process. However, this is
likely to be of the order of 10 to 15 over the full construction phase. The transport of
abnormal loads, which may lead to delays and cause inconvenience to other road
users, would be timed following consultation with the relevant authorities to minimise
disruption to the other road users.
16.1.6
Normal operation of the plant will give rise to traffic movements associated with the
50 personnel working at Damhead Creek 2. During outages for maintenance up to
200 temporary staff may visit the site for a period of about a month. Planned major
outages will occur annually.
16.2
Introduction
16.2.1
This Section presents the findings of a Transport Assessment, which investigated the
impact of Damhead Creek 2 on local traffic and infrastructure. Details of the
assessment methodology and significance criteria are provided, together with the
baseline conditions upon which the study and conclusions are based.
16.2.2
All significant potential impacts are discussed and proposed mitigation and
management methods are detailed, where appropriate.
16.2.3
Cumulative impacts of Damhead Creek 2 and other developments in the vicinity are
also considered.
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SECTION 16
16.3
16.3.1
T1
Manage and Invest
T2
Mobility Management
T4
Parking
T5
Travel Plans and Advice
T7
Rural Transport
T10
Ports and Short Sea Shipping
T12
Freight and Site Safeguarding
TP1
TP2
TP3
TP11
TP14
TP15
TP17
TP19
Integrated Transport Strategy
Assessment Criteria for Transport Proposals
Transport and the Location of Development
Facilities for Pedestrians and Cyclists
Safeguarding of Railway Land for Transport Purposes
Development Traffic and Heavy Goods Vehicles
Traffic and Management of Minor Roads
Vehicle Parking Standards
T1
T2
T3
T4
T10
T12
T13
T14
16.4
Impact of Development
Access to the Highways
Provision for Pedestrians
Cycle Facilities
Wharves
Traffic Management
Vehicle Parking Standards
Travel Plans
16.4.1
The transport assessment has been undertaken in accordance with the Department
for Transport’s (DfT) Guidance on Transport Assessment (March 2007).
16.4.2
Two potential construction scenarios are proposed for Damhead Creek 2, subject to
the connection offer from the National Grid Company (NGC). In order to provide a
comprehensive assessment of the impact of the proposed Development on the local
transport infrastructure it is important to consider both scenarios.
16.4.3
The current connection offer from NGC is such that Damhead Creek 2 could enter
operation in two phases, the first 500 MW in 2019 and the second in 2022. This
would mean that construction of Damhead Creek 2 would be similarly staggered with
the first construction phase commencing in 2016, and the second in 2019.
16.4.4
Each phase is expected to last for between 28 and 36 months with a peak on-site
staff resource in 2018 and 2021. Estimated staff resource profiles for the proposed
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SECTION 16
Development are presented in the Transport Assessment and based on data from the
construction of the existing Damhead Creek CCGT Power Station.
16.4.5
However, there is also the possibility of the connection offer being amended to allow
for connection of Damhead Creek 2 in one stage in 2016. If this were to occur,
construction of Damhead Creek 2 would commence in 2013, with a construction
period of between 30 and 36 months and a peak on-site staff resource in 2015.
16.4.6
Accordingly, the transport assessment has focused on 5 key years over the proposed
Development span. These are:
One Stage – Assuming Connection in 2016
2015 – the peak of construction;
2016 – the commencement of operation of Damhead Creek 2;
Two Stage – Assuming Connection in 2019 and 2022
2018 – the peak of construction for the first phase;
2021 – the peak of construction for the second phase, and including operational
traffic from the first phase; and
2022 – the commencement of operation of Damhead Creek 2.
16.4.7
Damhead Creek 2 will require approximately 50 staff to satisfy the daily operational
and maintenance requirements. Half of these staff will be on-site during normal office
hours, with the remainder operating under a five shift system with up to five on-site at
any one time.
16.4.8
Traffic associated with the full operation of the Development would be of the order of
40 vehicles per day, each making a return journey. A large proportion of these will be
due to staff movements and will, therefore, be predominantly local journeys.
16.4.9
A Capita Symonds study was undertaken, in June 2007, of the traffic volume,
composition and behaviour for the A228, south of Roper’s Lane roundabout, and
Stoke Road. The surveys were performed over three consecutive weekdays and the
results used to compile a ‘virtual day’ profile for each road that has been taken as the
baseline of these roads for the Transport Assessment.
16.4.10
For the purposes of this assessment, it has been assumed that the information for
Stoke Road is also indicative of the conditions experienced on Roper’s Lane.
16.4.11
The background traffic data for future years has been derived using the National
Road Traffic Forecasts 1997 (NRTF) growth factors for the relevant years to calculate
an estimated percentage traffic growth locally adjusted, using TEMPRO.
16.4.12
For the purpose of the environmental assessment peak hours, when considering the
available traffic data, have been defined as:
Monday to Friday 06:00 – 09:00
Monday to Friday 16:00 – 19:00
16.4.13
The definition is based on the fact that almost half of the average daily traffic flow is
generated during these times.
16.4.14
In order to understand the context and scale of the implications on local transport, the
baseline conditions have been determined through a desk study of current available
transport data and details of the local infrastructure.
16.4.15
Assessment of the impact on the local road network has been made using the
capacity of the roads affected by the traffic relating to the proposed Damhead Creek 2
as estimated using the Advice Note TA79/99 from the Design Manual for Roads and
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SECTION 16
Bridges and the ratio of flow to capacity (RFC). DfT guidelines suggest that the
threshold for satisfactory operation of a road is a RFC less that 85 per cent.
16.4.16
Assessment of the impact on the local road network has been made using the
capacity of the roads affected by the traffic relating to the proposed Damhead Creek 2
development as estimated using the Advice Note TA79/99 from the Design Manual
for Roads and Bridges and the ratio of flow to capacity (RFC). DfT guidelines suggest
that the threshold for satisfactory operation of a road is a RFC of less that 85 per cent.
16.4.17
The significance criteria of the impacts on the existing transport structure are defined
as:
Major:
High, lasting, disruption requiring extensive mitigation
Moderate:
RFC greater than 85 per cent AND/OR moderate disruption; requires
mitigation
Minor:
RFC less than 85 per cent AND low disruption; requires no mitigation
Insignificant:
RFC less than 85 per cent AND no perceived impact.
16.5
16.5.1
The local road network in the vicinity of the Damhead Creek 2 site is shown in
Figure 1.1. The M2 runs north west / south east approximately 11 km south-west of
the Damhead Creek 2 site, west of Strood. The major road link to the M2, from the
site, is the A289, Northern Relief Road, and then the A228, that passes to the
north west of the site, from the Isle of Grain.
16.5.2
Access to the existing Damhead Creek CCGT Power Station is provided by a
dedicated access road that leads around the Kingsnorth Industrial Estate,
immediately north west of the existing Damhead Creek CCGT Power Station, and
connects with Stoke Road.
Roper’s Lane connects Stoke Road to the A228
approximately 1.1 km north east of the junction for Hoo St. Werburgh and around
1.2 km south of High Halstow.
16.5.3
Using the Advice Note TA79/99 from the Design Manual for Roads and Bridges,
Roper’s Lane and Stoke Road are classified as Urban All Purpose roads under UAP3.
The capacity of these roads are therefore 1300 vehicles per hour in the busiest
direction. This figure assumes a 60:40 directional split ratio and therefore implies a
two-way capacity of 2167.
16.5.4
A major improvement scheme was undertaken to widen the A228. The conversion to
dual carriageway of the section from Four Elms Roundabout, north-east of Wainscott,
to the roundabout junction with Roper’s Lane was completed in 2005. Again, using
Advice Note TA79/99, the A228 is classed as a UAP2 dual carriageway with a busiest
direction capacity of 3200 vehicles per hour.
16.5.5
The A289 is a dual carriageway beginning at the start of the M2 and connecting with
the A228 at Four Elms Roundabout. The A289 is a type UAP1 dual carriageway with
a busiest direction capacity of 3600 vehicles per hour.
16.5.6
There are no bus stops serving the site. The nearest stops are on Main Road, Hoo St
Werburgh, on the A228 Ratcliffe Highway and in Stoke. The local rail line is for freight
only, the nearest passenger station being Gillingham Rail Station, over 6 km away.
16.5.7
Within the Hoo Peninsula access to public transport is generally poor. Less than
3 per cent of the working population use public transport to travel to work. The
consequence of the limited provision and use of the public transport system is that
private vehicle ownership is high. The Office of National Statistics states that
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approximately 45 per cent of households in the Hoo Peninsula have two or more cars
or vans. This is compared with 33 per cent for Medway and 29 per cent nationally.
16.5.8
The majority of people in the Peninsula travel to work by private transport
(85 per cent) over an average distance of approximately 15 km.
16.5.9
The Damhead Creek 2 site is remote in terms of neighbouring residential areas and,
as such, there is limited scope for walking or cycling to work. The cycle catchment
area encompasses Hoo St Werburgh, High Halstow and Stoke however these are
relatively small villages and unlikely to be home to significant numbers of
appropriately skilled construction or operational staff.
16.6
Potential Impacts
Construction
16.6.1
Construction of Damhead Creek 2 in two phases will result in two peak periods in
respect of construction traffic. The first peak will be around 2018 and the second
peak will be around 2021.
The peak construction workforce traffic will be
approximately 240 vehicles per day with an additional 60 HGVs per day.
16.6.2
It is anticipated that the HGV movements will be spread evenly over the course of the
working day at a rate of around 6 vehicles per hour between 08:00 and 18:00.
16.6.3
If Damhead Creek 2 is constructed in one phase, construction work is expected to
commence in 2013. The peak period in terms of on-site construction staff and
associated traffic will be around 2015 where 400 vehicles per day will travel to and
from the site. This construction scenario would also require approximately 100 HGVs
per day.
16.6.4
Construction work will be limited to:
Monday to Saturday
07:00 – 19:00 hours
16.6.5
Therefore, the bulk of the workforce traffic to and from, the site will occur between the
hours of 06:00 – 07:00 and 19:00 – 20:00.
16.6.6
The Transport Assessment identified the most sensitive part of the study area as
Roper’s Lane and Stoke Road where the road capacity is estimated at 1300 vehicles
per hour in the busiest direction. The A228 and A289 have substantially larger
capacities and will operate well within capacity for all the key assessment years. As
such, the discussions here concentrate on Roper’s Lane and Stoke Road.
16.6.7
Table 16.1 shows the background traffic and additional construction traffic for the two
peaks of construction should Damhead Creek 2 be built in two distinct phases.
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TABLE 16.1: CONSTRUCTION TRAFFIC FOR PEAKS OF TWO-PHASE
PROGRAMME
Hour
Ending
Background
(2018)
Damhead
Creek 2
(2018)
RFC(%)
Background
(2021)
Damhead
Creek 2
(2021)
RFC(%)
07:00
228
240
36
232
240
36
08:00
398
31
405
09:00
165
6
13
167
6
13
Mid-Peak
215
6
17
229
6
18
17:00
255
6
20
259
6
20
18:00
268
6
21
274
6
22
19:00
111
9
113
20:00
49
22
50
240
31
9
240
22
16.6.8
As can be seen, the construction traffic associated with Damhead Creek 2 will not
cause Roper’s Lane and Stoke Road to operate above the 85 per cent threshold for
satisfactory operation and therefore is unlikely to increase delays or congestion on
these roads.
16.6.9
Should Damhead Creek 2 be built in one phase the traffic generated by the
construction will increase as discussed earlier. Table 16.2 compares this construction
traffic to the anticipated background levels at the peak of construction, under this
scenario.
TABLE 16.2: CONSTRUCTION TRAFFIC FOR PEAK OF ONE-PHASE
PROGRAMME
Hour Ending
Background
(2018)
Damhead Creek 2
(2018)
RFC(%)
07:00
216
400
47
08:00
379
09:00
156
10
13
Mid-Peak
203
10
16
17:00
242
10
19
18:00
254
10
20
19:00
106
20:00
47
29
8
400
34
16.6.10
As before, the additional construction traffic associated with the one phase
construction of Damhead Creek 2 will not generate any exceedance of the guideline
85 per cent threshold for satisfactory operation of Roper’s Lane and Stoke Road.
16.6.11
For an initial assessment of the implications of the increased construction traffic
related to the construction of Damhead Creek 2, it is assumed that, without the use of
specific accident mitigation measures, accident frequency is directly proportional to
the volume of traffic on the road within the study area. Accident data was supplied by
Medway Council for the five year period 2002 – 2006.
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16.6.12
It is considered that the additional traffic associated with the construction of Damhead
Creek 2 may have the potential cause an additional 1 – 2 accidents throughout the
entire construction phase.
16.6.13
For either construction scenario, it is considered that the impact of the Damhead
Creek 2 construction traffic on the local road network will be insignificant.
16.6.14
The number of abnormal loads that would be required for the construction will be of
the order of 10 to 15 over the entire construction period. The exact number will
depend on the final configuration of the plant and will be defined upon completion of
the tendering process. The transport of abnormal loads can lead to disruption or
delays and is considered to be of moderate significance.
Operation
16.6.15
Damhead Creek 2 will require approximately 50 staff to satisfy the daily operational
and maintenance requirements. Half of these staff will be on-site during normal office
hours, with the remainder operating under a five shift system with up to five on-site at
any one time.
16.6.16
It is expected that a maximum of up to 25 vehicles would arrive or depart the site at
any one time, with the bulk of these representing staff arriving to site between 08:00 –
09:00 and departing between 17:00 – 18:00.
16.6.17
An example of a typical five shift system is shown in Table 16.3.
TABLE 16.3: CONTINUOUS FIVE SHIFT SYSTEM
Week
Monday
Tuesday
Wednesday
Thursday
1
M1
M1
N1
N1
2
A
A
A
3
N1
N1
4
M1
5
Friday
Saturday
Sunday
M1
M1
M2
M1
N1
N1
N2
A
A
A
M1 = Morning shift (8 hours)
M2 = Morning shift (12 hours)
N1 = Night shift ( 8 hours)
N2 = Night shift (12 hours) A = Afternoon shift
= day off
16.6.18
It is anticipated that the morning and afternoon shifts in the above example will
require five staff members to be on-site, reducing to four for the night shifts. As such
a maximum of five vehicles would arrive or depart before and after each shift change.
16.6.19
The total traffic associated with the operation of the plant will be of the order of
40 vehicles per day. A large proportion of these will be due to staff movements and
will, therefore, be predominantly local journeys. Damhead Creek 2 will also require
the intermittent delivery of various process chemicals.
16.6.20
The addition of 40 vehicles per day on the local road network will not be sufficient to
cause any roads included within the study area to operate above capacity and
therefore the impact is considered to be insignificant.
16.6.21
Damhead Creek 2 will be subject to a programme of annual schedule maintenance
outages. It is anticipated that during these outages, which will last for approximately
one month, around 200 temporary staff may visit the site and generate traffic
accordingly. This volume is significantly less than the anticipated construction traffic
for the Development.. Analysis of all roads within the study area shows that this
maintenance traffic will not cause any roads within the study area to operate above
capacity and therefore not increase delays or congestion on the local road network.
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16.7
Mitigation
Construction
16.7.1
It is anticipated that all deliveries will be brought to site via Junction 1 of the M2, the
A289 and the A228. The use of the A289 bypasses local town centres to eliminate
avoidable congestion. ScottishPower will encourage car sharing and the provision of
a minibus service by contractors so as to reduce the number of vehicles visiting the
construction site.
16.7.2
All vehicle movements associated with the construction of Damhead Creek 2 will
operate under a Transport Management Plan (TMP). The purpose of the TMP will be
to actively manage, in full consultation with the Highways Agency and Medway
Council, all potential issues resulting from the increased demand on the local
16.7.3
As part of the TMP review process, the Transport Manager will discuss all relevant
issues with all users of the Kingsnorth Business Park to establish the scope for the
provision of shared traffic management services. These discussions will also help to
identify any potentially significant cumulative impacts on the local transport
infrastructure and define appropriate mitigating measures that could be mutually
beneficial.
16.7.4
Construction contractors will be required to survey all routes to ensure that any
abnormal load can be transported to site by road with the least inconvenience to other
road users.
The contractors will be responsible for the cost of any route
strengthening requirements. Routes and timings of the transportation of abnormal
loads will be discussed with the relevant authorities in order to minimise disruption. A
police escort may also be used.
Operation
16.7.5
No perceivable impact is expected during the operation of the proposed Development
and no mitigation methods are deemed necessary.
16.8
Construction
16.8.1
Through the active management of the construction staff traffic and discussions with
the relevant authorities any negative effects, on the local transport network, will be
intermittent and temporary.
16.8.2
The local authorities will be notified, well in advance, of the transport of abnormal
loads. Full route surveys will be undertaken by the contractor to ensure the structural
suitability of any proposed route. All abnormal loads will be moved in accordance
with local authority instructions including use of a police escort, where necessary.
Full discussion of the potential issues reduces the significance of these movements
from moderate to minor.
16.8.3
Upon completion of Damhead Creek 2 all impacts will reduce to insignificant.
Operation
16.8.4
All operational impacts are insignificant.
16.9
16.9.1
The major, additional, consideration regarding the transport network and
infrastructure are the proposals for the construction of a new supercritical coal-fired
power station (Kingsnorth Units 5 and 6) on the area of land between the existing
Damhead Creek CCGT Power Station and the existing Kingsnorth Power Station, and
those for the Kingsnorth Business Park.
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16.9.2
The proposed date for the commencement of the construction of Kingsnorth Units 5
and 6 was originally identified as being March 2008 in the Kingsnorth ES. This start
date is now unlikely though site clearance has begun with construction at this stage
potentially starting in 2009. The peak additional traffic forecast, provided in the
associated Kingsnorth Units 5 and 6 ES, is almost 1000 cars and vans, plus 50 heavy
goods vehicles, per day. No details are given regarding the duration of this peak
construction period.
16.9.3
The ES for the Kingsnorth Units 5 and 6 development states that the arrivals to site of
heavy goods vehicles would be spread throughout the day at a rate of around 5 per
hour.
16.9.4
The Transport Assessment has assumed a cumulative likely worst case scenario by
applying the peak construction traffic figures for Kingsnorth Units 5 and 6 to all the
key assessment years of the Damhead Creek 2 development identified in
Section 16.4.
16.9.5
A planning application for Kingsnorth Business Park on land to the north and east of
the Damhead Creek 2 site has also been submitted on behalf of Goodman
Developments Limited. Included within the proposals are plans to widen and realign
Roper’s Lane and Stoke Road to improve accessibility for HGVs while increasing the
road capacity. Work on the roads was scheduled to commence in late 2008 and was
anticipated to last for around a year though this too has now been delayed with a start
in 2009 more likely. To mitigate any impact on traffic flow, including possible short
term road closures, the new road will be built off line of the existing one. If necessary,
closures are to be planned with, and consent obtained from, Medway Council.
16.9.6
Kingsnorth Business Park proposals include up to eight industrial units that are likely
to be constructed consecutively, depending upon market demands. Each unit will
give rise to additional traffic movements during construction and operation. The ES
supporting the Goodman Developments Limited project application stated that, at the
peak, up to 2250 HGVs per week may be required during the first phase of
construction. Assumptions of the construction working day, in the ES, equate this to
around 45 HGVs (90 trips) per hour.
16.9.7
Subsequent phases would require approximately 1500 HGVs per week (30 vehicles
per hour), at the peak of construction. However, the Transport Assessment has
assumed a likely worst case scenario of 45 HGVs per hour for all the key Damhead
Creek 2 assessment years.
16.9.8
No details are provided relating to anticipated construction workforce traffic or the
duration of the peak construction periods although construction of each unit is
anticipated to last for approximately one year with work on more than one unit at a
time unlikely.
16.9.9
Full operational traffic generation levels have also been estimated with 218 vehicles
(including 27 HGVs) arriving to site during the hour ending 09:00 and 338 vehicles
(including 20 HGVs) departing over the hour ending 18:00.
16.9.10
No details are provided, in the Goodman Developments Limited ES, regarding the
traffic generated by part-operation of the development. As a likely worst case, the
total operational traffic stated above has been applied in the assessment of all the key
years considered within the Transport Assessment.
16.9.11
The cumulative impact for these developments, in conjunction with Damhead Creek
2, is considered to be moderate during construction of Damhead Creek 2, in that
there is the potential for the combined developments to cause Stoke Road/Roper’s
Lane to operate above the threshold for satisfactory operation, significantly increasing
delays and congestion along this route for the hour of 06:00 – 07:00. However, active
management of the construction traffic through the Transport Management Plan of
Damhead Creek 2 could eliminate this.
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16.9.12
In addition, the road improvements proposed as part of the Goodman Developments
Limited Kingsnorth Business Park will increase the capacity of Roper’s Lane. Should
this development not go ahead, the combined traffic associated with Damhead Creek
2 and Kingsnorth Units 5 and 6 has the potential to cause Stoke Road/Roper’s Lane
to operate above the threshold for satisfactory operation, increasing delays and
congestion along this route for the hour of 06:00 – 07:00. Again, active management
of the construction traffic through the Transport Management Plan could eliminate
this.
16.9.13
Upon the commencement of operation of Damhead Creek 2, Roper’s Lane and Stoke
Road will operate well within capacity and therefore the impact will be insignificant.
16.9.14
There will be a requirement, due to the development of Kingsnorth Unit 5 and 6, for
the delivery of a number of abnormal loads, as with Damhead Creek 2. The transport
of abnormal loads can lead to disruption or delays, however this will only be of a
temporary nature and is considered to be of moderate significance. It will be
necessary to discuss and plan the movements of any abnormal loads, in advance,
with the relevant authorities. All discussions will, as a matter of course, take into
consideration the needs of both developments and ensure the least possible
cumulative impact on the local infrastructure.
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17
CULTURAL HERITAGE
17.1
Summary
17.1.1
A series of geoarchaeological investigations undertaken on and around the Damhead
Creek 2 site have suggested that a potential exists for palaeo-environmental material
to be present beneath the Damhead Creek 2 site. Borehole investigations indicated
the likely presence in the vicinity of Damhead Creek 2 of a palaeo-channel incised
into the London Clay bedrock, containing an important sequence of late-Pleistocene
deposits, including a complex sequence of clay silts containing organic material.
There is potential for early prehistoric archaeological material to be present amongst
the early Holocene alluvial silts underlying the Damhead Creek 2 site.
17.1.2
Evidence has been revealed by archaeological excavation also undertaken on and
around the Damhead Creek 2 site for multi-period activity from the Late Bronze Age
into the Early Iron Age, when the Damhead Creek 2 site became a part of the early
agricultural landscape of the Hoo Peninsula. Situated on low-lying land south west of
the main area of arable cultivation and settlement, the Damhead Creek 2 site was
used for grazing, and possibly seasonal salt-working.
17.1.3
During the 2nd and 3rd centuries AD, a Romano-British pottery production site was
established within the vicinity of the Damhead Creek 2 site, although its precise
location has not been revealed by previous archaeological and geophysical
investigations.
17.1.4
During the early medieval period the Damhead Creek 2 site once again became part
of the pastoral landscape of the Hoo Peninsula, whilst flooding during the medieval
period prompted the building of sea walls along the banks of the Damhead Creek and
the Damhead Fleet. These walls may have survived, albeit in a modified and
improved form into the 20th century.
17.1.5
From 1912, the Damhead Creek 2 site underwent its most intensive period of use,
when the RNAS Kingsnorth Naval Airship Station was established. The station was
of considerable significance in the history of British naval aviation, despite the fact
that it closed just eight years later. The majority of this activity was concentrated to
the north west of the site away from the development site.
17.1.6
Development of the Damhead Creek 2 site will not result in the loss of any listed
buildings, Conservation Areas or Scheduled Monuments; neither will it significantly
affect the setting of any such. Prior to mitigation, the construction of Damhead Creek
2 will have a slight-moderate adverse impact on palaeo-environmental and
archaeological remains.
17.1.7
It is proposed that an archaeological watching brief is employed during the
17.2
Introduction
17.2.1
This Section presents an impact assessment of Damhead Creek 2 on the potential
buried archaeological resource.
It includes discussion on: the assessment
methodology and significance criteria adopted in undertaking the assessment; the
baseline conditions on which the Development’s impact is assessed; the potential
(pre-mitigation) significant environmental impacts which the Development may have;
the mitigation measures to be adopted; and, the resultant residual (post-mitigation)
significant environmental impacts of the construction and operation of the
Development. Cumulative residual impacts are also considered within this Section.
17.2.2
Consultations undertaken as part of this archaeological impact assessment have
informed the assessment methodology and impact assessment, the key objectives
being:
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To describe the survival and extent of known or potential archaeological features
that may be affected by the proposal;
To provide an evaluation of their importance;
To assess the likely scale of impacts, both construction-related and operational,
arising from the proposal;
To assess the potential significance of the likely impacts;
To outline appropriate mitigation measures to avoid, reduce or remedy adverse
impacts; and
To provide an assessment of any residual impacts that may persist after
mitigation.
17.3
17.3.1
BE6
Management of the Historic Environment
QL7
Archaeological Sites
BNE20
Scheduled Ancient Monuments
BNE21
Archaeological Sites
17.4
17.4.1
This assessment has been conducted in accordance with the Institute of Field
Archaeologists (IFA) standards and guidance for archaeological desk-based
assessments (IFA, 1993).
17.4.2
The archaeological resource may be previously designated by registration, listing or
scheduling, or reported on national or local historic environment databases, including
the National Monuments Record (NMR) and the Kent Historic Environment Record
(HER). Previously unidentified resources are identified from specialist study of the
landscape and historical records (both documentary and cartographic).
17.4.3
The desk-based assessment of the resource has been carried out within an area
defined as 2 km around the Damhead Creek 2 site. This is referenced as the ‘study
area’ throughout this Section. The desk-based assessment was undertaken to
determine the likely nature, depth, extent, preservation and importance of any
archaeological remains that may be present within 2 km of proposed Development.
The Ordnance Survey Central National Grid Reference for the site is TQ 812 728.
17.4.4
A gazetteer of archaeological sites, findspots and Listed Buildings identified within the
study area is provided in Appendix J and is cross-referenced by a map reference
number in bold (e.g., Figure 17.1:1). All archaeological sites and finds are mapped on
Figure 17.1 and are described in the Archaeological Background. This is provided in
full in Appendix K.
17.4.5
Available geotechnical and land quality records (including palaeo-environmental
borehole surveys, logs and reports) and the results of earlier site-specific evaluations
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conducted during site investigations in advance of the development of the existing
Damhead Creek CCGT Power Station (archaeological evaluations, watching briefs
and limited excavations conducted between 1998 and 2001) have informed the geoarchaeological history of the site which is summarised below.
17.4.6
The North Kent Rapid Coastal Zone Assessment Survey of 2004 / 2005 was also
reviewed for relevant information relating to the River Medway.
17.4.7
To compliment the desk–based assessment, a site walkover was undertaken by a
qualified archaeologist from Pre-construct Archaeology to validate the desk-based
findings where possible.
Importance of the Receptor
17.4.8
Determination of the importance of receptors (site and features) has been based upon
existing designations, whilst professional judgements have been made in the case of
undesignated receptors in accordance with the criteria stipulated in Table 17.1.
TABLE 17.1: CRITERIA USED TO DETERMINE IMPORTANCE OF THE
ARCHAEOLOGICAL RECEPTOR
Importance
Description
International
Archaeological Sites or Monuments of International importance, including World Heritage
Sites.
National
Ancient Monuments scheduled under the Ancient Monuments and Archaeological Areas
Act 1979, or archaeological sites and remains of comparable quality, assessed with
reference to the Secretary of State’s non-statutory criteria (these are set out in PPG16,
Annex 4).
Regional
Archaeological sites and remains which, while not of national importance, fulfil several of
the Secretary of State’s criteria and are important remains in their regional context.
Local
Archaeological sites and remains that are of low potential or minor importance.
Negligible
Areas in which investigative techniques have produced negative or minimal evidence for
archaeological remains, or where previous large-scale disturbance or removal of
deposits can be demonstrated.
17.4.9
The determination of magnitude of impact is based upon an understanding of how
and to what extent the proposed development of Damhead Creek 2 would impact
upon the receptors. The criteria used are shown in Table 17.2.
TABLE 17.2: CRITERIA USED TO DETERMINE MAGNITUDE OF CHANGE
Magnitude
Description
High Adverse
Complete removal of an archaeological site. Severe transformation of the setting or
context of an archaeological monument or significant loss of key components in a
monument group. Complete removal or transformation (eg desiccation or contamination)
of palaeo-environmental deposits leading to complete loss of research knowledge.
Medium Adverse
Removal of a major part of an archaeological site’s area and loss of research potential.
Partial transformation of the setting or context of an archaeological site or partial loss of
key components in a monument group. Partial removal or transformation of palaeoenvironmental deposits leading to a loss of research knowledge. Introduction of
significant noise or vibration levels to an archaeological monument leading to changes to
amenity use or, accessibility or appreciation of an archaeological site. Diminished
capacity for understanding or appreciation (context) of an archaeological site.
Slight Adverse
Removal of an archaeological site where a minor part of its total area is removed but that
the site retains a significant research potential. Minor change to the setting of an
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archaeological monument. Minor removal of palaeo-environmental deposits that form
part of a wider surviving research resource.
Negligible
No physical impact or change. No observable change in setting or context. No impact
from changes in use, amenity or access.
Slight Beneficial
Decrease in visual or noise intrusion on the setting of an archaeological site or
monument. Improvement of the wider landscape setting of an archaeological site or
monument.
Medium
Beneficial
Significant reduction or removal of visual or noise intrusion on the setting of an
archaeological site or monument. Reduction or removal of significant vibration levels.
Improvement of the setting of an archaeological site or monument. Enhanced capacity
for understanding or appreciation (context) of an archaeological site or monument.
Improvement of the cultural heritage amenity, access or use of an archaeological site or
monument.
High Beneficial
Exceptional enhancement of an archaeological site, its cultural heritage amenity and
access or use.
Uncertain
The magnitude of the impact cannot be predicted.
Significance of Environmental Effects
17.4.10
The significance of the effects of the proposed Development on archaeological
remains is determined by:
The importance of the receptor; and
The magnitude of change.
17.4.11
Table 17.3 provides a matrix to demonstrate how the significance of effect has been
assessed.
TABLE 17.3: THE SIGNIFICANCE OF ENVIRONMENTAL EFFECTS
Adverse
Beneficial
Impact
High
Medium
Low
International
High
Moderate
Slight
Importance
Adverse
Adverse
Adverse
High
Moderate
Slight
Importance
Adverse
Adverse
Adverse
Regional
Moderate
Slight
Slight
Importance
Adverse
Adverse
Adverse
Slight
Slight
Importance
Adverse
Adverse
Negligible
Neutral
Neutral
Importance
National
Local
June 2009
Negligible
Neutral
Neutral
Neutral
Low
Medium
High
Slight
Moderate
High
Beneficial
Beneficial
Beneficial
Slight
Moderate
High
Beneficial
Beneficial
Beneficial
Slight
Moderate
Moderate
Beneficial
Beneficial
Beneficial
Slight
Slight
Beneficial
Beneficial
Neutral
Neutral
Neutral
Neutral
Neutral
Neutral
Neutral
Neutral
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17.5
Statutory Constraints
17.5.1
There are no Scheduled Monuments within the Damhead Creek 2 site, or within the
study are (2 km radius of the Damhead Creek 2 site).
17.5.2
There are no Listed Buildings within the Damhead Creek 2 site, however there are
three Listed Buildings situated within the wider study area. These include:
Cold Arbour Farm House (Grade II), approximately 1.5 km north of the
Damhead Creek 2 site;
Lancers Farm House (Grade II), approximately 1.1 km west of the Damhead
Creek 2; and
White Hall House (Grade II), approximately 1.1 km to the north of the Damhead
Creek 2 site.
17.5.3
There are no Conservation Areas within the Damhead Creek 2 site, or within the
wider study area. .
17.5.4
The Damhead Creek 2 site is located in an Archaeological Notification Area, a nonstatutory designation used by Kent County Council and Medway Council to indicate
areas of recognised archaeological potential. Medway Council will consult the County
Archaeologist regarding any applications for planning consent made in these areas
(Simon Mason, personal communication).
Site Location
17.5.5
The Damhead Creek 2 site is situated on the southern side of the Hoo Peninsula, and
on the northern side of the estuary of the River Medway within the historic parish of
Hoo St. Werburgh. The Damhead Creek 2 site is situated on an area of flat,
predominantly open ground, lying at heights of between 2.10 m AOD and 3.25 m
AOD. Damhead Creek is approximately 100 m south east of the Damhead Creek 2
site, whilst the Medway is approximately 800 m to the south.
Summary of the Geological and Palaeo-Environmental Background
17.5.6
The Geological Survey of Great Britain 1:50 000 scale map of the area (Sheet 272,
‘Chatham’) indicates that the Damhead Creek 2 site is underlain by a layer of
estuarine alluvium, which in turn overlies solid Eocene London Clay. The British
Geological Society (BGS) map indicates that towards the north-western corner of the
Damhead Creek 2 site the underlying drift deposits comprise Head Brickearth, which
overlies Quaternary River Terrace 1 Gravels, deposited during the Pleistocene period.
17.5.7
The marshes of the Medway estuary are rich in palaeo-environmental alluvial
deposits. These deposits can provide information about the environment of the area
during the prehistoric period. Holocene alluvial deposits have been identified on the
existing Damhead Creek CCGT Power Station site, the Damhead Creek 2 site and at
the adjacent Kingsnorth Units 5 and 6 site.
17.5.8
As part of the mitigation measures associated with the construction impact of the
existing Damhead Creek Power Station a series of investigations were undertaken to
gain an understanding of the deeply buried stratigraphic sequences that were to be
impacted upon during the construction process. Limited geotechnical fieldwork was
undertaken by Williamson and Pine in 1996, which produced a basic stratigraphic
framework for subsequent investigations. In 1997 Dr Martin Bates conducted a
geoarchaeological investigation using wire-line percussion drilling and a geophysical
survey in order to ascertain the nature and extent of palaeo-environmental
archaeology at the site (Bates, 1997). A final phase of investigation included drilling
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an additional borehole in 1999 in order to recover organic sequences, and assess the
samples recovered in order to ascertain their palaeo-environmental content.
17.5.9
As part of a pre-determination archaeological evaluation undertaken in order to
determine the archaeological impact of the proposed development of two 800 MW
supercritical coal fired generating units at the Kingsnorth Power Station (Kingsnorth
Units 5 and 6), a field investigation of the site which borders the southern boundary of
the Damhead Creek 2 site was undertaken in summer 2007. Four boreholes were
drilled under the supervision of Bates, in order to understand the nature of the deeply
buried sequences preserved in the vicinity of the proposed Kingsnorth Units 5 and 6
site, the history of formation, and consequently any archaeological relevance (Waters,
2007). Discussion of the findings of the borehole surveys can be found in
Appendix K.
17.5.10
The 1997 and 1999 investigations revealed that much of the proposed development
site is underlain by a complex sequence of deposits, probably spanning a period of at
least 100 000 years, representing part of the Pleistocene record previously little
understood in the lower Medway. The investigations also indicated the presence of a
possible palaeo-channel incised into the London Clay bedrock. The London Clay was
overlain by a major stratigraphic sequence of Pleistocene deposits comprising a basal
gravel layer overlain by a complex sequence of clay silts, which was sealed by flint
gravels. In turn the latter were overlain by Holocene alluvium.
17.5.11
Palaeo-environmental evidence was obtained from the clay silts complex and the
ostracod fauna contained within were analysed in order to reconstruct the palaeoenvironmental circumstances of deposition (Figure 17.1: 1). The deposit had been
laid down during temperate interglacial conditions during the Ipswichian interglacial
(c.125 000 before present (BP)). The discovery of a Pleistocene interglacial deposit
with archaeological potential is of considerable local and regional importance.
17.5.12
The presence of molluscan remains in these sediments suggests the likely presence
of foraminifera and ostracoda, the analysis of which may enable further palaeoenvironmental reconstruction. The presence of molluscan remains also indicate a
potential for dating the sediments, whilst the presence of sand in many of the deposits
indicates that direct dating using Optically Stimulated Luminescence dating should be
possible. The acquisition of absolute dating must be a key objective of any future
palaeo-environmental investigations in the area.
17.5.13
Although no palaeo-environmental material was recovered from the Holocene
alluvium, evidence of charcoal, burnt flint and possible ceramic material recovered
from Borehole 4 at Kingsnorth suggests that the Holocene alluvium at least
represents considerable potential for archaeological evidence of human activity during
the last 7000 years.
Archaeological and Historical Background
17.5.14
The full archaeological and historical background is included in Appendix K and
summarised below. Numbers in bold typing refer to the individual sites shown on
Figure 17.1.
Palaeolithic Period (500 000 – 10 000 BC)
17.5.15
The Palaeolithic period in Britain was characterised by alternating glaciations (Ice
Ages) and temperate interglacial periods. In the periglacial margins south of the icesheets and during the warmer interglacials high energy meltwater rivers deposited
huge spreads of gravel along their lower courses; and it is from these gravel terraces
that much of the evidence of Palaeolithic activity have been recovered. Substantial
quantities of Lower Palaeolithic Acheulian flint handaxes and smaller quantities of
Clactonian flake-based implements have been found in riverine gravel deposits in
northern Kent.
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17.5.16
The Ipswichian clay silt complex identified in the Damhead Creek palaeoenvironmental sequence is considered unlikely to produce any in-situ archaeology,
however it is possible that reworked artefacts may be present in the gravel units
deposited under periglacial conditions either side of this temperate interlude (Bates,
1997: 4).
17.5.17
Despite the comparatively rich Palaeolithic resource in north and west Kent, no finds
dated to the period have been identified in either the Damhead Creek 2 site or within
the wider study area.
Mesolithic Period (10,000 - 4,000 BC)
17.5.18
During the climatic amelioration at the end of the Devensian glaciation around
10 000 years BP, deciduous forests began to colonise the future south eastern corner
of Britain, whilst the proliferation of flora and fauna attracted nomadic groups of
human settlers. At the same time rising sea-levels created an environment
characterized by salt marshes, shallow tidal creeks and sand banks along the lowlying estuarine fringes and marshlands of north Kent, which offered abundant
opportunities for hunting, wildfowling and fishing.
17.5.19
Approximately 20 m to the east of the eastern boundary of the Damhead Creek 2 site,
a number of pieces of residual late Mesolithic / early Neolithic flints were recovered
during archaeological investigations within the existing Damhead Creek Power
Station mitigation land (to the east of Area 1). These finds included up to 20 hammerstruck flakes, blades and a core although no evidence was found of permanent or
transient settlement of any kind (Griffin, 2004: 79), suggesting that the low-lying
marshland environment and tidal creeks of the present Damhead Creek 2 site were
seasonally exploited by groups during the period (Figure 17.1: 9).
Neolithic Period (4000 - 2000 BC)
17.5.20
The earliest settled farming societies had emerged in the British Isles by circa 6000
BP. The early Neolithic period in Kent was characterised by the construction of large
numbers of substantial earthwork monuments, including causewayed enclosures and
earthen and stone long barrows.
17.5.21
A number of residual Neolithic finds in the area included a polished stone axe
fragment and a fragment of a leaf-shaped arrowhead recovered from a ditch,
suggesting that the area remained marginal, probably seasonally exploited estuarine
wetlands (Figure 17.1: 11). Other prehistoric finds that may indicate an ephemeral
presence near the Damhead Creek 2 site during the period include a couple of shards
of very coarse flint-tempered pottery accompanied by a large flint flake, found on the
Damhead Creek foreshore (Figure 17.1: 13).
17.5.22
Evidence of less transient middle or late Neolithic activity was discovered within the
study area on the Hoo Flats, some 1.7 km to the south west of the Damhead Creek 2
site (Figure 17.1: 10). As rising sea levels continued to inundate peripheral land
beside the Thames and the Medway, extensive areas of marshland formed, leading to
the creation of substantial peat deposits (examples of prehistoric peats in the study
area include Figures 17.1: 3 and 5). The Neolithic inhabitants of the Hoo area
established at least one trackway across these marshes, presumably to provide
access to and from the wet intertidal zone for activities such as grazing, fishing and
wildfowling, and either they or their later prehistoric descendents may have been
responsible for a number of other brushwood trackways revealed by the erosion of
the present foreshore (Figures 17.1: 4, 6 and 8).
17.5.23
No evidence of permanent Neolithic settlement has been found within the study area,
and it is probable that people chose to settle in the agricultural landscape of the
higher gravel terraces to the north-west of the Damhead Creek 2 site. Evidence of
agricultural land divisions, represented by a series of ditches and an alignment of six
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post-holes discovered in the mitigation land may be Neolithic in origin (Figure 17.1:
12)
Bronze Age (2000 – 700 BC)
17.5.24
During the Bronze Age the Thames Valley and Estuary achieved social and political
primacy in southern Britain, as new settlement and large-scale cultivation spread
along the river and its major tributaries.
17.5.25
The earliest phase of the Bronze Age was characterized by the emergence of
distinctive Beaker pottery forms, which may have represented status symbols
associated with the development of a newly stratified social order (Ashbee, 2005).
Two shards of Beaker pot were recovered in the vicinity of the Damhead Creek 2 site.
The location of these finds is indicated as Area 14 on Figure 17.3.
17.5.26
The Middle Bronze Age witnessed the start of an extended period of more intensive
land use on either side of the lower Medway. Archaeological investigations on the
gas pipeline route (for the existing Damhead Creek Power Station), which is shown as
Area 12 on Figure 17.3, revealed a number of ditches and pits, whilst a pit in Area 14
(shown on Figure 17.3) contained an articulated calf skeleton (Figure 17.1: 15), which
may represent evidence of contemporary ‘ritual’ activity.
17.5.27
Archaeological investigation at Damhead Creek also revealed evidence of Late
Bronze Age agricultural land division, and the Damhead Creek 2 site and its environs
may represent the earliest formal agricultural landscape on the Hoo peninsula (Griffin,
2004: 80). A number of NW-SE aligned ditches running parallel with modern field
boundaries between the marshland margin and the spinal ridge of the Hoo peninsula
included a pair of linear ditches that possibly represent a droveway (Figure 17.1: 14),
along which livestock were driven to the low-lying areas to graze on marsh pastures
during the summer months.
17.5.28
Permanent Late Bronze Age settlement is most likely to have been situated on the
higher ground to the north-west of the Damhead Creek 2 site, where settlementrelated activity has been found in the form of a number of founder’s hoards, including
one discovered at Roper’s Farm (Figure 17.1: 16; possible erroneous NGR on HER).
Iron Age (700 BC – 43 AD)
17.5.29
Until recently little was known about settlement in Kent during the Late Bronze Age /
Early Iron Age transition period. Archaeological investigations associated with the
existing Damhead Creek CCGT Power Station have provided some evidence about
this period in the lower Medway area.
17.5.30
Land divisions, agricultural and industrial practices established towards the end of the
Bronze Age persisted into the Iron Age. A roundhouse was identified in Area 14
(shown in Figure 17.3) in the vicinity of a dense scatter of post-holes and clay-lined
pits, which may have been associated with salt making (Figure 17.1: 17). The
discovery of briquetage fragments in Areas 12 and 14 (shown in Figure 17.3)
confirmed the proximity of the Damhead Creek 2 site to a salt-works.
17.5.31
Although no further occupation evidence was found, a cremation/ funeral pyre deposit
containing calcined bone was excavated in Area 12 (shown in Figure 17.3, and
Figure 17.1: 18). Other Early Iron Age features in the area included a number of
postholes parallel to modern field boundaries close to the Late Bronze Age droveway
(Johnson, 1999: 7) and a number of linear features, again probably associated with
agricultural boundaries (Figures 17.1: 19 and 20).
17.5.32
There was a significant gap in activity in the study area between the Early and Late
Iron Ages. The field system that emerged during the Late Iron Age shared the same
orientation and similar boundaries as its Early Iron Age predecessor (Figures 17.1: 21
and 22). Activity focused upon the site of the Early Iron Age roundhouse, and a
replacement was built within a small enclosure that may have been used as a pen for
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livestock. It appears that the Damhead Creek 2 site resumed its seasonal pastoral
function (Griffin, 2004: 81). Despite this functional continuity, a shift in activity to the
southern margins of the Damhead Creek 2 site was observed (Johnson, 1999: 26).
17.5.33
Although little evidence of Late Iron Age salt production has been identified at
Damhead Creek, elsewhere on the north Kent and Essex coasts the industry
continued into the 1st and 2nd centuries AD, leaving a distinctive signature in the form
of the ‘red hills’ made up of the burnt clay and briquetage debris left behind by the
process of extracting salt by boiling seawater (Rippon, 2000: 69-70). A Late Iron Age
/ early Roman salt making site was identified in the vicinity of the foreshore south of
Kingsnorth Power Station (Figure 17.1: 25).
17.5.34
During the Late Pre-Roman Iron Age (LPRIA; c. 150 BC – 43 AD) mints opened in
Canterbury and Rochester, and group of four LPRIA coins and a pre-Claudian
denarius were discovered by metal detection at Tudor Farm, near Stoke (Figure 17.1:
24 and 26).
17.5.35
Although a possible LPRIA site on the Hoo marshes to the south-west of Damhead
Creek 2 site may have continued to flourish into the 1st and even 2nd centuries
(Figure 17.1: 23), the absence of ‘Belgic’ pottery from Damhead Creek suggests that
activity may have ceased in the area of the proposed development by c. 50 BC
(Griffin, 2004: 81).
Roman Period (43 – 410 AD)
17.5.36
The Thameside and Medway marshes were centres of Romano-British industrial
activity until the 3rd century AD, with the latter area particularly associated with the
production of salt during the 1st and 2nd centuries, and the manufacture of fine
reduced wares on the Upchurch Marshes from the late 1st century (Pollard, 1988:
173). Up to four 1st and 2nd century salt extraction sites have been identified on
islets in the Medway estuary, and it is possible that a mound in Bishops Marsh may
have represented another of these sites (Figure 17.1: 44).
17.5.37
Saltern debris has also been recovered from the Hoo Saltings, where traces of
1st century occupation material have been identified (Figure 17.1: 29). Further
evidence of Romano-British domestic activity has been recovered from Stoke (Figure
17.1: 27), a short distance from a group of cremation burials discovered in the Stoke
Marshes north-east of Damhead Creek (Figure 17.1: 28), whilst a single shard of a
2nd century Roman flared bowl was found on the foreshore at Slede Ooze, southeast of the Damhead Creek 2 site (Figure 17.1: 34).
17.5.38
Salt working may have taken place on the estuarine marshes to the south and southeast of the Damhead Creek 2 site during the 1st and early 2nd centuries, and a
spread of Roman pottery with briquetage was identified during the construction of a
jetty at Kingsnorth Power Station in 1975 (Figure 17.1: 32).
17.5.39
During the mid-2nd century much of the Damhead Creek 2 site was turned over to
industrial use, indicated by a pottery production site that covered an area of at least
120 m by 50 m within and between Areas 3 and 11, shown on Figure 17.3. The bulk
of the pottery recovered consisted of North Kent White Slipped Ware (NKWS). A
deep cut feature in Area 14 (shown on Figure 17.3) was interpreted as a clay
extraction pit (Figure 17.1: 30). Further possible evidence of 2nd and 3rd century
Roman pottery production was identified in Area 12 (shown on Figure 17.3), where a
shallow pit filled with a burnt deposit was interpreted as the rake-out from a kiln
(Figure 17.1: 31).
17.5.40
No trace of the kilns themselves was discovered in either area during the existing
Damhead Creek Power Station Phase I archaeological investigation, and a recent
magnetic survey of the area immediately south of the Damhead Creek 2 site also
failed to reveal definitive evidence of intact kilns or industrial sites (GSB Prospection
Ltd, 2007).
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17.5.41
The discovery of a locally produced amphora with a coating of black resin on the rim
gave rise to the suggestion that the vessels may have been manufactured as
packaging for locally-produced commodities, such as salt, or possibly salted fish
and/or fish sauce (Griffin, 2004: 47, 82).
17.5.42
Romano-British industrial activity in the vicinity of the Damhead Creek 2 site, came to
an end in the 3rd century. A thin layer of grey clay that blanketed Area 11 (shown on
Figure 17.3) has been interpreted as evidence of a marine incursion that took place
during or after the 4th century (Johnson, 1999: 10).
Saxon / Early Medieval Period (410 - 1066 AD)
17.5.43
A nunnery dedicated to St Werburgh is known to have existed at Hoo by the end of
the 7th century, whilst the foundation of a Minster Church at Hoo has been dated to
the early or mid-8th century. This Minster church was one of 14 founded in the
diocese of Rochester, and would have been the ecclesiastical centre of the peninsula
during the pre-parochial Middle Saxon period, fulfilling the role of a mother church to
dependent churches at High Halstow, All Hallows and St Mary’s Hoo.
17.5.44
Both Hoo and Kingsnorth share a Saxon derivation, the former meaning ‘place at the
spur of land’, whilst ‘Cyning snad’ or ‘Cyninersnode’, which first appears in the
Cartularium Saxonicum of circa. 850 denotes ‘a detached piece of land belonging to
the king’ (Mills, 1991: 177).
17.5.45
A number of Middle Saxon pits and channels situated either side of an undated
trackway were revealed by excavation in Area 1, shown in Figure 17.3 (Johnson,
1999: 13, 14, 26). Subsequent analysis of environmental samples indicated that the
area was likely to have been grazed by livestock, although there were indications of
arable cultivation in the wider vicinity (Figure 17.1: 34).
Medieval Period (1066 – 1540 AD)
17.5.46
By the time of the Domesday survey Hoo had acquired manorial, hundredal and
parochial status. Both arable cultivation and livestock husbandry were practiced,
whilst the neighbouring manor of Stoke possessed a fishery, presumably based on
the Stoke Marshes. Archaeological traces of a medieval timber fishtrap have been
identified in Oakham Marsh, approximately 2 km south-east of the Damhead Creek 2
site (Williams & Martin, 2002: 20; Figure 17.1: 35).
17.5.47
Owing to the continued effects of post-glacial sea-level rises and land surface
subsidence in the south-east England by the 10th century high spring tides had begun
to overflow the lower parts of the land surface in the region (Brandon & Short, 1990:
75). Whilst sea defences in the Fenland and Romney Marsh had enabled the
inhabitants to reclaim and cultivate former marshland by the 11th century (a process
known as ‘inning’), it appears that the tidal wetlands along the north Kent coast
estuaries remained tidal salt marshes into the medieval period (Rippon, 2000: 70). By
the early 13th century the frequency of high spring tides and surges led to the
erection of sea and river walls in north Kent to exclude the rising tide.
17.5.48
There is some documentary and archaeological evidence for the construction of sea
walls on the Medway marshes between Hoo and Stoke in the 13th century. A sea
wall was erected during the 13th century to protect agricultural land north of the Hoo
Flats, permitting the construction of the 13th - 15th century moated site at Abbot’s
Court, approximately 2 km south-west of Damhead Creek 2 site (Figure 17.1: 36).
Indirect evidence of limited reclamation in the study area includes an environmental
sample taken from Area 1, shown in Figure 17.3, which revealed that at least part of
the Damhead Creek 2 site lay under arable cultivation in the medieval period,
although the majority of low-lying fields in the vicinity of the Damhead Creek 2 site
had reverted to permanent pasture before the mid-19th century (Griffin, 2004: 83;
Tithe Apportionment, 1841).
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17.5.49
A single medieval findspot was recorded within a 2 km radius of the Damhead Creek
2 site, consisting of a late 14th century bronze seal and die representing the Hundred
of Wouldham, discovered in a field on Barton Farm approximately 900 m north-west
of the Damhead Creek 2 site (Figure 17.1: 37).
Post-Medieval (1541 – 1900 AD)
17.5.50
The post-medieval rural settlement pattern of the manors of Hoo and Stoke,
comprised dispersed farmsteads. These farmstead cultivated arable land on the
higher ground to the north and west and grazed livestock on the low-lying ground to
the south and east. These farms were established during the medieval period. Most
of the major farms in the vicinity of the Damhead Creek 2 site are depicted in
Figure 17.4. Indeed, a number of present-day farms in the vicinity have medieval
origins including Malmaynes Farm (first mentioned in a document of 1240), Tudor
Farm (first mentioned in 1244) and White Hall Farm, first mentioned in 1436 (Entergy
Power Group, 1998: 7:8; Hasted, 1798: 253).
17.5.51
The Grade II listed 16th century White Hall House survives to the present,
approximately 1.1 km to the north of Damhead Creek 2 site (Figure 17.1: 108). Of
the other listed post-medieval buildings in the study area, Cold Arbour Farm House is
a Grade II timber-framed brick clad house a short distance to the north-west of White
Hall Farm, approximately 1.5 km north of the Damhead Creek 2 site (Figure 17.1:
106), whilst Lancers Farm House is a 17th century Grade II timber-framed and
weatherboarded structure, situated on Jacob’s Lane to the west of Kingsnorth
Industrial Estate, approximately 1.1 km west of Damhead Creek 2 site (Figure 17.1:
107).
17.5.52
The Tithe Apportionment map of 1841 (not illustrated) depicts a clear division in land
use between the arable fields north of Barton’s Farm, and the pasture and marsh
grazing to the south and east. Field names listed in the Apportionment provide a
clear indication of the formerly low-lying and occasionally waterlogged nature of land
in the southern and eastern extremities of the Damhead Creek 2 site. Field names
include Rushy Marsh, Twelve Acres and Upper and Lower Hooks, all of which were
designated as pasture. A narrow and sinuous unit of land along the west bank of
Damhead Creek was known as the Salt Ground (Tithe Apportionment, 1841).
17.5.53
An Admiralty chart of 1847 (Figure 17.5) illustrates the isolated situation of Teapot
Hall, a probable post-medieval structure surrounded by a four-sided enclosure at the
southernmost tip of Hoo Marshes (Figure 17.1: 38). This structure is also shown on
the First to Third Editions of the Ordnance Survey Maps, shown in Figures 17.6, 17.7
and 17.8 respectively.
17.5.54
There appears to have been little change in land use between the 1840s and 1870,
when the First Edition Ordnance Survey map was published (Figure 17.6). A number
of earthworks of uncertain date appear to have offered protection to the permanent
pastures from flooding from both Damhead Creek (Figure 17.1: 46), and from
Damhead Fleet (Figure 17.1: 48), albeit with varying degrees of success. Both the
latter wall and the south-east facing wall in Rushy Marsh appear to have been
overwhelmed by floodwaters from Damhead Fleet, which may have been dammed in
order to provide a lasting solution to the problem of flooding in the lower pastures.
17.5.55
A large sub-rectangular enclosure depicted on the First Edition Ordnance Survey Map
south of Damhead Creek in the vicinity of the later power station has been variously
interpreted as representing a post-medieval livestock enclosure, or a salt-panning site
of the same period (Figure 17.1: 56). Whatever its original purpose, by 1870 the
enclosure appears to have been used as a sheepfold. This is one of a number in the
area of rough marsh grazing in the south-eastern part of the study area, and the find
referenced in Figure 17.1: 47 almost certainly represents another nearby example.
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17.5.56
Although the area of Damhead Creek 2 site continued to be dominated by sheep
farming in 1870, a number of the isolated farmsteads and cottages cultivated
orchards within their immediate vicinities, including White Hall Farm, Slate House,
Burnt House Farm and Lancers and Ashcole (later Eschol) on Jacob’s Lane.
17.5.57
A number of marsh features that lay within the study area but outside the environs of
Damhead Creek 2 site were recorded on the First Edition Ordnance Survey Map,
including a hardway in Hoo Flats (Figure 17.1: 45), a hardway in Slede Ooze on
Oakham Marsh (Figure 17.1: 50) and a hillock and trackway in the Stoke Saltings
(Figure 17.1: 49).
17.5.58
Little change seems to have occurred in the vicinity of the Damhead Creek 2 site
between the publication of the First and Second Edition Ordnance Survey map of
1897, shown in Figure 17.7, although the progressive drying-out of the Damhead
Fleet appears to have resolved the drainage problem in the adjacent pastures, both of
which seem to have been largely reclaimed by the end of the century.
17.5.59
Both the Second and Third Edition 25” to 1 mile Ordnance Survey maps of 1897 and
1908 (neither illustrated) depicted small circular embanked features on the east bank
of Damhead Creek that may have represented redundant salterns (Figures 17.1: 51
and 52), however neither they, nor an enigmatic mound shown on the 25” Second
Edition in the vicinity of Slede Creek (Figure 17.1: 53) could be identified during the
foreshore survey in the North Kent Rapid Coastal Zone Assessment Survey 2004 /
2005. Similarly two circular embanked features depicted in the Oakham Marsh
saltings in the 25” Second Edition could not be identified during the recent coastal
survey (Figures 17.1: 54 and 55), although the surveyors did identify possible postmedieval sea defences (Figure 1.4: 39), elements of two possible post-medieval or
modern landing stages (Figures 17.1: 40 and 41) and a dump of modern roof tiles in
the Oakham Marsh area (Figure 17.1: 42).
17.5.60
A number of post-medieval wharves depicted on the Second Edition also appear to
have survived in varying states of repair along the western bank of Damhead Creek
and the Stoke Saltings foreshore (Figure 17.1: 58 – 62).
Modern (1901 AD - Present)
17.5.61
The first section of the South Eastern Railway line between Hoo Junction and Port
Victoria was opened in 1882. Although the railway was never a commercial success,
a station halt was added at Beluncle in 1906 (Figure 17.1: 67). Around the same time
the narrow-gauge Chattenden Naval Tramway was extended from the Lodge Hill
Magazine to Sharnal Street.
17.5.62
By the time the Third Edition Ordnance Survey was published in 1909, shown in
Figure 17.8, a number of significant changes had taken place in the study area. A
submerged telephone cable had been laid across the Medway, which headed inland
west of the Damhead Creek 2 site (Figure 17.1: 68), whilst the fields to the north-west
of Eschol Road had been largely turned over to orchards. Cutting through the
orchards, on a north-west to south-east alignment was an earthen embankment,
marked ‘Railway in course of construction’. The latter represented the eastwards
extension of the Chattenden Naval Tramway, and its construction represented the
start of the most intensive utilization of the Damhead Creek 2 site to date.
17.5.63
By 1909 the Admiralty had already purchased Kingsnorth Farm from a local farmer
named Walter Miskin, possibly with a view to establishing an aerodrome for fixedwing aircraft, perhaps similar to the experimental station at nearby Grain (Brooks,
1990: 60).
17.5.64
The decision to build a military airship station at Kingsnorth was made in 1912, and
construction of the first of two airship hangars began in 1913. It soon became
apparent to the Admiralty that additional land was required to permit the airships to
manoeuvre on the ground and a further 81½ acres of (predominantly marsh) land at
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Barton’s Farm were purchased for this purpose. A site plan of RNAS Kingnorth can
be seen in Figure 17.9, and shows the extent of the land acquired. In August 1914,
the Royal Naval Air Service (RNAS) took possession of the Damhead Creek 2 site,
shortly after which operations commenced with the RNAS’ first two (foreign-built)
airships (Figure 17.1: 69).
17.5.65
A complex of buildings soon spread north of the airship hangars. These additional
buildings are shown in Figure 17.10. The majority of technical buildings, including a
large hydrogen gas generating station with several gasholders, a depot for gas
cylinders and numerous workshops, machine rooms and stores developed to the
north-west of the airship sheds. These buildings can be seen in Figure 17.11. In
order to transport the heavy hydrogen generating plant to the site the Naval Tramway
was extended to the Medway, where it terminated at the newly built Abbott’s Court
Jetty.
17.5.66
RNAS Kingsnorth had four key wartime roles, including the design, development and
manufacture of airships, and until 1916 it was the lead training establishment for
airship crews (Smith, 1999: 4.2). The station’s role in research and development was
crucial to British military airship development, and several families of anti-submarine
patrol craft were designed and tested there. Following the transfer of the aircrew
training function to Cranwell, the station became the lead RNAS Experimental Station
and one of six Admiralty Airship Construction Stations (Smith, 1999: 5.1).
17.5.67
By early 1919 the Admiralty was confronted with the problem of disposing of a large
number of redundant wartime facilities. The decision to close RNAS Kingsnorth
appears to have been made in March of that year, and by the end of August the
Drawing Office had closed down. By 1920 the RNAS had vacated the station, which
was partially abandoned thereafter.
17.5.68
Archaeological investigation of the site of the former RNAS station in advance of the
construction of the existing Damhead Creek Power Station located a number of
structural remains associated with the southern shed, including a group of concentric
concrete arcs at the east end of this hangar in Area 1 (shown on Figure 17.3), and it
was possible to survey the overall layout of the concrete base and associated
foundations of the shed in Area 2 (shown on Figure 17.3) (Griffin, 2004: 15).
17.5.69
At some point during the 1920s the sheds and a number of the former technical
buildings were used for wood pulping (Smith, 1999: 5.1). A log flume was excavated
between the Medway and the west end of the southern shed, where a rectangular log
pond was built.
17.5.70
At the end of the 1920s Berry Wiggins established a small oil and petrol refinery on
and in the vicinity the Damhead Creek 2 site, making use of many of the former
RNAS buildings (Figure 17.1: 71). Berry Wiggins also reopened both the Kingsnorth
branch of the Naval Tramway and Abbott’s Court Jetty, although these were
supplanted by the Bee Ness Jetty (completed in 1937), which enabled oil to be
transferred between the refinery and tankers moored off Stoke Ooze (Figure 17.1:
72). The railway closed in 1940.
17.5.71
The 1938 Provisional Ordnance Survey map, shown in Figure 17.12, indicates the
extent to which Berry Wiggins retained the fabric of the old RNAS station, although
the superstructures of the airship sheds appear to have been demolished during the
1930s. The concrete foundations of these are still visible on the 1946 RAF vertical
aerial photograph of the Damhead Creek 2 site and the surrounding area, shown on
Figure 17.13. This photo also shows the early post-war scale of the oil tank facility.
17.5.72
During the Second World War a possible ‘military installation’ was established in the
vicinity of the present Kingsnorth Power Station (Figure 1.4: 70). The nature and
extent of this structure is presently unknown. The presence of large numbers of
concrete cylinders (of a form and dimensions reminiscent of Second World War anti-
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tank cylinders) around the Kingsnorth Industrial Estate may be an indication of the
reuse of former Second World War anti-invasion defences during the post-war period.
17.5.73
By the early 1960s the Kingsnorth area was becoming increasingly industrialized.
The Berry Wiggins oil refinery had expanded considerably since 1946, and work had
begun on the present Kingsnorth Power Station in 1963 (Figure 17.1: 73). The
Kingsnorth Power Station was built by the Central Electricity Generating Board
(CEGB) between 1963 and 1973, one of a group of ten 2000 MW Power Stations built
by the Board. Kingsnorth Power Station can be fired both by coal and oil, and two
jetties were built in the Medway to receive fuel from both colliers and tankers,
although coal was the sole fuel source after 1978. The station also possesses an
auxiliary back-up gas turbine plant.
17.5.74
The 1969 Ordnance Survey Map, shown in Figure 17.14, shows the construction of
the existing Kingsnorth Power Station Units 1 – 4 in progress. A group of hostel
buildings for workers employed during the construction of the station was built
immediately to the east of the former railway embankment, adjacent to the western
construction lay-down area, and their foundations are still visible on the recent aerial
photograph shown in Figure 17.15. Berry Wiggins erected a functional two-storey
office block in the western construction lay-down area, which still stands. To the
south of this area a large rectangular pond had been created, which appears to have
been fed by a linear drain that ran from the power station construction site across an
area of rough ground to the south. This may have served as a sedimentation basin,
designed to drain the site during the construction process. Rushes currently indicate
the area of the now-infilled pond. The area east of the office block seems to have
been largely cleared by this stage and little if anything of the fabric of the former
RNAS station is visible. To the north of the cleared area a number of oil refinery
structures, tanks and filter beds are visible.
17.5.75
The completed Kingsnorth Power Station was first depicted on the 1974 1:50 000
Ordnance Survey Map (not illustrated), protected to the south by new flood defences
on the banks of the Medway. Little change appears to have occurred in the vicinity
during the 20 years before the next Ordnance Survey Map of the site was published
in 1993. The 1993 Ordnance Survey Map can be seen in Figure 17.16. Since that
date major changes have taken place to the north of the original Kingsnorth Power
Station. These include the construction of the existing Damhead Creek Power Station
and areas of associated landscaping, in addition to the closure of the Berry Wiggins
Oil Refinery. The closure of the Oil Refinery is illustrated to have included the
demolition and clearance of large areas formerly occupied by oil tanks, such as the
group that stood within the boundary of the Damhead Creek 2 site shown on
Figure 17.16. Subsequently the Kingsnorth Industrial Estate was established on the
former Berry Wiggins site.
17.5.76
There is a substantial number of named and unidentified vessels in the creeks and
channels of the marshes and flats. All of these vessels appear to be post-medieval or
modern, and include the 1924 Medway steamer, the Medway Queen (Figure 17.1: 78)
and at least one (Figure 17.1: 84), and possibly three German First World War UBoats (Figure 17.1: 85). At least eight unidentified barges were identified from the
1946 RAF aerial photograph (Figure 17.1: 79), whilst a number have been spotted in
subsequent coastal surveys and from more recent aerial photographs (Figure 17.1:
86 – 91).
Sites of Uncertain Date
17.5.77
There are a number of potential archaeological sites within the vicinity of the
Damhead Creek 2 site that cannot be ascribed to any particular historic period, and
for which function or purpose is uncertain. Several of these sites have been identified
through the interpretation of aerial photographs, whilst others were identified during
the North Kent Rapid Coastal Zone Assessment Survey of 2004 / 2005.
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17.5.78
Situated south-east of Kingsnorth Power Station is the site of an undated enclosure
identified from the 1946 RAF aerial photograph (shown in Figure 17.13) and in the
vicinity of the possible livestock enclosure depicted on the First to Third Editions of
the Ordnance Survey (shown in Figures 17.6, 17.7 and 17.8 respectively)
(Figure 17.1: 92). No trace remains of a former landing stage identified from aerial
photographs immediately south of the Power Station (Figure 17.1: 93), or of an
unmapped ring ditch in the vicinity (Figure 17.1: 96).
17.5.79
A square enclosure identified from a 1946 aerial photograph (shown in Figure 17.13)
to the east of Kingsnorth Power Station has not been shown on any mapping, though
it may have represented a former salt-working site (Figure 17.1: 94). Another square
enclosure, between Damhead Creek and Slede Ooze remains unidentified, and the
inaccessibility of its location prevented closer assessment (Figure 17.1: 95).
17.5.80
No trace remained in 2004 of a circular embankment feature a short distance to the
west of Kingsnorth Power Station identified from aerial photographs (Figures 17.1: 97
and 100). A linear feature on the foreshore of Slede Creek proved to have been a
tangle of modern hawsers, iron tubing and other unidentified metalwork (Figure 17.1:
98), whilst a strandline of well-sorted and rounded flint pebbles and broken shell was
recorded on nearby Slede Ooze (Figure 17.1: 99).
17.5.81
Two parallel rows of abraded rounded wooden posts observed at the northern edge of
Hoo flats may represent an unidentified archaeological feature (Figure 17.1: 101),
whilst a group of three wooden stakes in the foreshore of Damhead Creek proved to
be inaccessible, preventing further investigation (Figure 17.1: 102).
17.5.82
A series of small enclosures, situated between the 30 m and 35 m counters near to
Tunbridge Hill approximately 1.7 km north-west of the site, remain unexplained
(Figure 17.1: 103).
17.5.83
Finally two undated foreshore features include a possible fish weir, observed on the
northern edge of Hoo Flats (Figure 17.1: 104) and a probable fish weir on the west
bank of Damhead Creek (Figure 17.1: 105).
17.6
Archaeological Potential of the Damhead Creek 2 Site
17.6.1
This assessment has identified a number of known sites of archaeological potential
on the Damhead Creek 2 site and within the wide 2 km radius study area. These
known sites mainly relate to the palaeo-environmental, late prehistoric, Roman, postmedieval and modern landscapes.
Palaeo-Environmental
17.6.2
Investigations conducted by Martin Bates on the existing Damhead Creek Power
Station site and on the site proposed for the development of the Kingsnorth
supercritical generating units have indicated a high potential for recovering palaeoenvironmental remains at the Damhead Creek 2 site. The Holocene alluvial deposits
laid down approximately 6000 years BP may contain preserved organic and palaeoenvironmental material, and a borehole at the Kingsnorth Supercritical site has
recently revealed the presence of material of archaeological potential at a depth of
circa. 0.7 m below surface level.
17.6.3
A well-defined Pleistocene palaeo-channel sequence, buried beneath Holocene
floodplain sediments, is of considerable local and regional importance within the
context of the lower Medway and landscape development during the later Pleistocene
in the south-east of England. Clay-silt deposits laid down during temperate conditions
during the Ipswichian interglacial (circa. 125 000 years BP) contain organic material
that offers the potential both for further palaeo-environmental reconstruction and for
dating the sediments directly using Optically Stimulated Luminescence (Waters,
2007). Palaeo-environmental deposits on the site would be of regional importance.
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Prehistoric
17.6.4
There is little evidence for Palaeolithic activity within the study area, although residual
artefacts may be present in the gravel units deposited in the palaeo-channel under
periglacial conditions. The earliest of these deposits were encountered at depths of
between approximately 5 m below surface level, whilst the later Devensian gravels
were encountered between 0.80 m and 2.15 m below surface level. The potential for
Palaeolithic archaeology is therefore low to moderate. Any Palaeolithic material
encountered would be of regional importance
17.6.5
Apart from some residual late Mesolithic/early Neolithic flints recovered a short
distance to the east of Damhead Creek 2 site, little evidence has been found in the
study area for Mesolithic activity. Environmental evidence indicates that Damhead
Creek 2 site was situated in a low-lying marshland environment, possibly seasonally
exploited by Mesolithic groups. The archaeological potential is therefore low. Any
Mesolithic material encountered would be of regional importance.
17.6.6
The area remained marginal during the Neolithic period, most likely used as
seasonally exploited wetlands. A number of possible Neolithic finds within the
Damhead Creek 2 site, and the presence of a Neolithic trackway across the marshes
of the Hoo Flats approximately 1.7 km to the south-west suggest that there is a
moderate potential that remains from this period may occur in the area of the
proposed development. Any Neolithic material encountered would be of regional
importance.
17.6.7
Archaeological evidence of Middle Bronze Age activity, in the form of land divisions
and a potential ritual deposit has mainly been identified on the higher ground northeast of Damhead Creek 2 site. The Late Bronze Age saw the beginning of more
intensive land-use in the study area, and the Damhead Creek 2 site became
incorporated into an early formal agricultural landscape. Evidence of seasonal
pastoralism has been identified with the discovery of a droveway, whilst seasonal
industrial activity, such as the extraction of salt from seawater took place in the wider
area. The potential for Late Bronze Age remains is therefore moderate to high. Any
Late Bronze Age material encountered would be of regional importance.
17.6.8
During the Late Bronze Age/Early Iron Age transition period a roundhouse was built in
the vicinity of a possible salt works a short distance to the east of the Damhead Creek
2 site. Agricultural boundaries of the period were also identified, and it is probable
that the Late Bronze Age patterns of seasonal pastoralism and salt-working persisted
into the period. Following a hiatus during the Middle Iron Age, it appears that a
similar pattern of activity resumed during the Late Iron Age, although no cultural
evidence was found of Late Pre-Roman Iron Age activity. The archaeological
potential for Iron Age activity is therefore moderate. Any Iron Age material
encountered would be of local importance.
Roman
17.6.9
Salt-making took place on the Medway marshes throughout the 1st and 2nd centuries
AD, although it is likely that the slightly higher ground of the Damhead Creek 2 site
precluded such activities in the immediate vicinity. During the 2nd and 3rd centuries
the site became a centre of pottery production manufacturing Upchurch-type wares.
Limited archaeological excavation and two phases of geophysical survey in the
vicinity (1999 and 2007) have failed to reveal the location of the kilns themselves,
which are considered likely to have been situated towards the southern boundary of
the Damhead Creek 2 site. The possibility that the vessels manufactured by these
kilns were filled on or nearby the Damhead Creek 2 site with locally produced
commodities would merit further archaeological investigation in the event that the
Development were to impact on areas of the Development site that had not previously
been the subject of physical investigation. The potential for Roman industrial
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archaeology is therefore high. Any Roman material encountered relating to pottery
production would be of regional importance.
Early Medieval / Saxon
17.6.10
A small number of Middle Saxon pits discovered on the site of the existing Damhead
Creek CCGT Power Station indicate that agricultural activity resumed in the vicinity by
the 8th or 9th centuries, although this probably consisted of seasonal grazing. Given
the proximity of these remains to Damhead Creek 2 site, the potential for archaeology
from the period is therefore moderate. Any Saxon material encountered would be of
local importance.
Medieval
17.6.11
It is likely that the Damhead Creek 2 site continued to be grazed during the medieval
period, although the effects of rising sea levels and increased storminess during the
13th century led to the construction of sea defences near Damhead Creek 2 site.
Although there is no evidence that formal marshland reclamation took place during
the medieval period in the vicinity, it is possible that the earthen sea walls west of
Damhead Creek (in the proposed eastern construction lay-down area) depicted on
the earliest Ordnance Survey maps may have had medieval antecedents. There is
therefore a moderate potential for Damhead Creek 2 site to contain features
associated with medieval sea defences. Any medieval material encountered would be
of local importance.
Post-Medieval and Modern
17.6.12
Cartographic evidence exists for the modification and improvement of existing
earthwork sea defences in the vicinity of both the Damhead Creek and the Damhead
Fleet during the post-medieval period.
17.6.13
Between 1912 and 1920, a section of the Damhead Creek 2 site was part of RNAS
Kingsnorth, which became the major centre for the design, development, manufacture
and trialling of military airships during the First World War (Smith, 1999). The majority
of the technical, industrial and regimental buildings were situated to the north of
RNAS Kingsnorth, and a number of these overlapped into the north-west of the
Damhead Creek 2 site. Indeed, the site of the west end of the northernmost of the
station’s two airship hangars falls within the Damhead Creek 2 site. The airship
sheds were of considerable importance, and elements of the southern hangar were
surveyed and excavated as part of the mitigation for the existing Damhead Creek
Power Station. Although the hangars were demolished during the 1930s, it appears
that this part of the area was not subsequently developed and it is possible that traces
of the foundations and of the tram tracks at the western end of the north hangar may
be identifiable in the archaeological record. However, RNAS Kingsnorth appears to
have made little use of the remainder of the Damhead Creek 2 site.
Further
(unidentified) tracks were observed in-situ in the northern construction lay-down area.
The potential for post-medieval archaeology across the Damhead Creek 2 site is
therefore moderate to high, whilst that for modern archaeology in the western and
eastern areas of the Damhead Creek 2 site is high. Any post-medieval or modern
material encountered would be of local importance.
Past Impacts on the Damhead Creek 2 Site
17.6.14
Potential impacts upon palaeo-environmental and archaeological remains caused by
previous land-use must also be considered as previous impact can affect the survival
of archaeological deposits. No major previous impacts that may have affected the
archaeological potential of the Damhead Creek 2 site have been identified from
historic maps of the area prior to the construction of the existing Damhead Creek
CCGT Power Station. As part of the mitigation for the existing Damhead Creek
CCGT Power Station, groundworks within the Damhead Creek 2 site, including the
‘receptor site’ in the south east corner, the ‘haul road’ for construction traffic and the
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sedimentation basin in the south west corner were subject to archaeological
monitoring. It is possible that groundworks associated with construction of the postwar surface oil tanks in the northern construction lay down areas may have had a
localised impact upon palaeo-environmental and archaeological remains within that
area.
17.6.15
In summary, previous ground investigation works (archaeological, geoarchaeological
and geotechnical) and the historic mapping resource suggest that the sequence of
deposits in the proposed development area have remained substantially intact.
Previous impacts on the site are low.
17.7
Potential Impacts
Construction
17.7.1
Initial groundworks in development schemes, such as the creation of general
‘formation levels’, the setting out and consolidation of access roads for plant and
machinery can impact to a greater or lesser degree upon buried archaeological
remains, depending upon the nature and extent of these works.
17.7.2
Due to the nature of the below-ground deposits, it is considered likely that most if not
all of the structures of Damhead Creek 2 will be constructed with piled foundations.
Piling and excavation are likely to affect the upper levels of the Holocene alluvial
deposits (where present), which may contain the remains of activity that has occurred
on site since the Bronze Age.
17.7.3
In addition, the cutting of service trenches and connections can cause significant
localized impacts upon buried palaeo-environmental and archaeological remains.
Remains elsewhere in the Damhead Creek 2 site have been noted from 0.80 m below
ground level to at least 5.00 m below ground level.
17.7.4
The impacts of the proposed Development will be high.
archaeological resource will be as follows:
The impacts on the
If remains survive on the site dating to the Palaeolithic, Mesolithic, Neolithic, late
Bronze Age and Roman periods, the construction impacts of the proposed
Development on this regionally significant resource will be moderate adverse
without mitigation; and
If remains survive on the site dating to the palaeo-environmental, Iron Age,
Saxon, medieval, post-medieval and modern periods, the construction impacts
on this locally significant resource will be slight adverse without mitigation.
Operation
17.7.5
No adverse impacts to the archaeological resource caused by the operation of
Damhead Creek 2 have been identified. Any palaeo-environmental deposits such as
peat and alluvium may be affected by de-watering associated with the use of piled
foundations. Should this type of deposit become de-watered, it may become
desiccated and lose its palaeo-environmental value. The palaeo-environmental
deposits should be monitored for a period after construction in order to ascertain if dewatering is taking place and appropriate action taken if this is found to be occurring.
17.8
Mitigation
Construction
17.8.1
The assessment has concluded that the impact of the proposed Development on
archaeological and palaeo-environmental remains will be slight-moderate adverse
without mitigation.
17.8.2
It is clear that the nature and survival of the archaeological resource on the Damhead
Creek 2 site is not fully understood at this stage. For this reason it is proposed that an
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archaeological watching brief is employed at the Damhead Creek 2 site during the
construction stage of the project. Furthermore it is recommended that once the impact
of the development of Damhead Creek 2 is finalised (but prior to construction),
archaeological trial trenching should be carried out within areas of construction
impact. Further sampling of the palaeo-environmental deposits may be required,
although some mitigation of this resource has already been carried out by previous
investigations on the Damhead Creek 2 site.
17.8.3
The extent of mitigation works would be agreed with Kent County Council once the
proposed development has been finalised and the extent of impact can be
ascertained. The results of the initial trenching work may lead to a requirement for
further mitigation works such as excavation.
Operation
17.8.4
A requirement for archaeological mitigation during the operational phase of Damhead
Creek 2 is not anticipated. De-watering of peat or alluvial deposits may occur after
construction and should be monitored with any necessary mitigation measures
agreed with the council.
17.9
Construction
17.9.1
Table 17.4 summarises the residual effects during construction.
TABLE 17.4: SUMMARY OF RESIDUAL EFFECTS DURING CONSTRUCTION
Baseline
Resource
Importance
and Potential
of Resource
Impact of
Proposed
Development
Magnitude of
Impact before
Mitigation
Proposed
Mitigation
Residual
Impact after
Mitigation
Local/High
Predicted high
Slight Adverse
Palaeoenvironmental
sampling
Neutral
Palaeolithic
Regional/Lowmoderate
Predicted high
Moderate
Adverse
Trial trenching
in the first
instance
Slight Adverse
Mesolithic
Regional/Low
Predicted high
Moderate
Adverse
Trial trenching
in the first
instance
Slight Adverse
Regional/
Moderate
Predicted high
Moderate
Adverse
Trial trenching
in the first
instance
Slight Adverse
Late Bronze
Age
Regional/
Moderate-High
Predicted high
Moderate
Adverse
Trial trenching
in the first
instance
Slight Adverse
Iron Age
Local/ Moderate
Predicted high
Slight Adverse
Trial trenching
in the first
instance
Neutral
Roman
Regional/High
Predicted high
Moderate
Adverse
Trial trenching
in the first
instance
Slight Adverse
Local/ Moderate
Predicted high
Slight Adverse
Trial trenching
in the first
instance
Neutral
Palaeoenvironmental
deposits
Neolithic
Early Medieval/
Saxon
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Baseline
Resource
Importance
and Potential
of Resource
Impact of
Proposed
Development
Magnitude of
Impact before
Mitigation
Proposed
Mitigation
Residual
Impact after
Mitigation
Medieval
Local/ Moderate
Predicted high
Slight Adverse
Trial trenching
in the first
instance
Neutral
Post-Medieval
Local/
Moderate-High
Predicted high
Slight Adverse
Trial trenching
in the first
instance
Neutral
Local/High
Predicted high
Slight Adverse
Trial trenching
in the first
instance
Neutral
Modern
Operation
17.9.2
No adverse impacts to the archaeological resource caused by the operation of
Damhead Creek 2 have been identified. There are therefore no significant residual
impacts.
17.10
17.10.1
Cumulative impacts associated with the various developments in the area would
relate to the visual impact of the projects to sites of historic interest rather than an
impact on paleo-environmental deposits. This is due to the site specific location of
such deposits. Therefore, there would be no additional physical impact caused by the
development of Kingsnorth Units 5 and 6 and the Kingsnorth Business Park with
regard to archaeology and cultural heritage contained within the Damhead Creek 2
site.
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SOCIO-ECONOMICS
18
SOCIO-ECONOMICS
18.1
Summary
18.1.1
During the peak of construction, the workforce would total approximately 1000 in the
event that Damhead Creek 2 was developed in one phase. In the event of two phase
development, the workforce would total approximately 600. It is hoped that much of
the workforce will be recruited locally. During operation, approximately 50 personnel
would be required.
18.1.2
Total investment in Damhead Creek 2 will be of the order of £600 million. In addition,
operational and maintenance costs will be of the order of £27 million per annum, a
significant proportion of which will benefit the local economy.
18.1.3
It is considered that the development of Damhead Creek 2 would have a positive
socio-economic impact on the surrounding area, providing additional jobs and
investment whilst also helping the wider UK economy through the development of a
highly cost effective means of electricity generation.
18.2
Introduction
18.2.1
This Section presents the findings of the assessment of the socio-economic impact of
Damhead Creek 2. Details of the assessment methodology and significant criteria
are provided, together with the baseline conditions upon which the study and
conclusions are based.
18.2.2
All significant potential impacts are discussed and proposed mitigation and
management methods are detailed, where appropriate.
18.2.3
Cumulative impacts of Damhead Creek 2 and other developments in the vicinity are
also considered.
18.3
18.3.1
SP1
SP4
CC7
RE1
RE2
RE3
RE4
RE6
KTG2
KTG3
Sub-regions in the South East
Regeneration and Social Inclusion
Infrastructure and Implementation
Contributing to the UK’s Long Term Competitiveness
Supporting Nationally and Regionally Important Sectors and
Clusters
Employment and Land Provision
Human Resource Development
Competitiveness and Addressing Structural Economic Weakness
Economic Growth and Employment
Employment Locations
SS1
SS4
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Spatial Priorities for Development and Investment in Kent and the
Role of the Settlement Hierarchy
Priority for Previously Developed Land and a Sequential Approach
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SOCIO-ECONOMICS
ME1
EP1
EP2
EP4
to the Location of Development
Medway
Land, Workforce, Education and Skills
Employment Land Provision
Locations of Strategic Importance for Business, Industrial or
Distribution Uses
S12
ED1
ED5
ED7
ED8
18.4
Kingsnorth
Existing Employment Areas
Proposed Employment Areas
Special Industrial Uses
Industrial Uses Not in a class
18.4.1
In order to fully assess the impact of Damhead Creek 2 it is necessary to fully
determine the baseline conditions of the affected areas of the socio-economy.
18.4.2
A desk study was undertaken to establish the existing situation for the region in line
with the defined significance criteria. The assessment focused on the Hoo Peninsula
and Medway as a whole. The likely impacts of Damhead Creek 2 proposal were then
considered within the context of these conditions and the appropriate local authority
objectives for social and economic development.
18.4.3
Comparisons were also made with the present positions of Kent, the south east, and
the rest of the country.
18.4.4
The significance criteria of the impacts on the socio-economy are defined as:
High:
Large, or long-term, change to the socio-economy (Affecting direct
and indirect employment and induced contributions to the local
economy; greater than 5 years)
Moderate:
Small, or short-term, change to the socio-economy (Affecting direct
and indirect employment; less than 5 years)
Insignificant:
No perceivable impact.
18.4.5
Impacts may also be classified as positive or negative.
18.5
18.5.1
The Damhead Creek 2 site is located on the Hoo Peninsula in Medway, North Kent.
The local population is approximately 13 000 with the population of Medway, as a
whole, standing at around 250 000. Strood, on the western border with Gravesham,
is the administrative centre of Medway.
18.5.2
According to the Kent and Medway Structure Plan 2006, Medway has the largest
labour force in Kent with a large number of residents commuting to London to work.
The average distance travelled to work by the economically active people of the
Peninsula is 15 km, compared with 13 km for Medway and 10 km for the south east.
18.5.3
Chatham Dockyard was once the centre of the traditional industries of shipbuilding,
defence and heavy engineering. The closure of the dockyard led to severe economic
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problems for the region. The local economy has gradually recovered, through
diversification, shifting emphasis towards transport and communication, finance and
education. The dock was divided up, after the closure, and the east basin now
operates as a commercial port.
18.5.4
Table 18.1, based on information from the Office of National Statistics, shows the
sector breakdown of the working population of Peninsula and Medway, compared
with regional and national details.
TABLE 18.1: EMPLOYEES IN EMPLOYMENT
Peninsula
(%)
Medway
(%)
South East
(%)
England
(%)
Agriculture and Fishing
1.9
0.8
1.5
1.5
Energy and Water
2.4
1.0
0.7
0.7
Manufacturing
13.3
13.3
12.3
15.0
Construction
12.5
10.1
7.1
6.8
Distributions, Hotels and
Restaurants
20.5
21.6
20.7
21.6
Transport and
Communications
9.6
8.2
8.1
7.1
Banking, Finance and
Insurance
14.6
17.4
20.7
18.0
Public Administration,
Education and Health
20.3
22.7
23.6
24.1
Other Services
4.9
4.9
5.3
5.2
18.5.5
The employment patterns in Medway are generally similar to that of the South East
and England as a whole. The manufacturing industry in Medway is in decline as a
major employer having seen its contribution to the employment landscape drop by
almost 50 per cent from 1996 to 2006.
In spite of this, specialist, hi-tech,
manufacturing still remains one of the area’s key employment sectors. Although the
impact has been more significant in Medway, similar trends in the manufacturing
industry can be observed both in the south east and nationally.
18.5.6
The trends in the unemployment rates for Medway and Kent follow the fluctuations
observed for Great Britain with Medway tending to be slightly higher. The Office of
National Statistics recorded an unemployment rate of 5.3 per cent for Great Britain
and Kent for the year ending September 2008. Medway was slightly higher with a
figure of 6.1 per cent. .
18.5.7
Of the unemployed population in Medway, the proportion of people with no, or an
unknown level of, qualifications is comparable with that of Great Britain, 40 per cent
and 38 per cent respectively. The level of those educated beyond A-Level standard is
just over half that of Great Britain, 8 per cent compared to 15 per cent.
18.6
Potential Impacts
Construction
18.6.1
During the peak of construction, assuming development of Damhead Creek 2 in one
phase, the workforce would total approximately 1000, of which up to 40 per cent could
be recruited from local residents. The construction period, again assuming one phase
development, will be approximately 36 months in duration and will provide a tangible
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amount of work for local contractors. Works machinery will be required for all aspects
of the Development and may be sourced from local plant hire companies.
18.6.2
The civil works that will constitute the initial stages of the construction will require a
small unskilled workforce. The subsequent mechanical and electrical works will utilise
a larger workforce with more specialised skills.
18.6.3
Workers from outside the area are likely to commute weekly to the Damhead Creek 2
site. The temporary accommodation requirements will be provided by local hotels
and guesthouses, or privately, generating more business in this sector of the local
economy, and increasing spending in the area. Construction staff typically comprises
a high proportion of single males who make relatively low demands on education,
health and recreational facilities. In the event that large numbers of the workforce are
recruited from outside the area, it is anticipated that no significant impact will be made
on such services.
18.6.4
The money invested into the local economy, in terms of construction staff wages and
project expenditure on local goods, services and contractors, will generate further
economic activity and indirect employment benefits.
The manufacturing and
construction industries form a significant part, almost 29 per cent, of the local
employment landscape. Throughout the construction of Damhead Creek 2, every
effort will be made to ensure that as much of the investment as is possible remains in
the region.
18.6.5
All construction activities will be carried out under the provisions of the Construction
(Design and Management) Regulations 2007.
Operation
18.6.6
Damhead Creek 2 will be designed to operate, predominantly, under automatic
control. Approximately 50 staff will be required for roles and tasks associated with the
daily operational and maintenance requirements of the new plant. These jobs will be
permanent and non-seasonal, and will exist for the operational lifetime of Damhead
Creek 2, expected to be approximately 35 years.
18.6.7
Skilled operators will make up approximately 95 per cent of the operational workforce.
The skilled operators will have a background appropriate to their discipline and will
receive additional training relating to power plant operation. The knowledge of the
manufacturer will be transferred to the operating staff during the commissioning
phase of the Development by ensuring full and active participation in the trials and
testing of the plant equipment. Staff at all levels will receive training on process and
emission control and will be able to benefit from the experience of the operators of the
existing Damhead Creek CCGT Power Station. Regular appraisals will be made of all
training requirements. Damhead Creek 2 will be operated in accordance with the
manufacturer instructions.
18.6.8
It is anticipated that around half of the operational staff will work on a five-shift
system, with four on duty at any one time. The remaining staff will work during normal
office hours.
18.6.9
As part of the plant operation and maintenance regime, permanent staff will be
responsible for the management of sub-contractors. Local companies may be
approached to provide mainly unskilled and semi-skilled services and it is estimated
that a further 25 jobs may be created, on the basis of the levels of permanent staff in
these local service industries. Typical requirements would include security, general
maintenance and catering.
18.6.10
The operational and maintenance costs of Damhead Creek 2 will be in region of
£27 million per annum. In addition to the use of local services, a significant proportion
of this will serve to benefit the local economy in terms of employee wages, which is
most likely to be spent on local purchases and local capital expenditure.
June 2009
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SOCIO-ECONOMICS
18.6.11
The Kent and Medway Structure Plan 2006 expresses concern regarding the
apparent disparity between development and the levels of investment in the
community and social infrastructure. In addition to the ongoing financial contribution
that Damhead Creek 2 would provide to the region, ScottishPower have an extensive
history of consulting with, and supporting, local communities and are committed to
maximising local benefits, wherever possible.
18.6.12
ScottishPower Learning was established in 1996 as a way of providing development
opportunities for young people and encouraging local economic development. The
scheme is focused on improving the employability of young people through the
teaching and development of a broad range of key employment skills. ScottishPower
Learning provides school-, community- and work-based training by sharing the
resources of ScottishPower and the skills of their employees.
18.6.13
By taking a long-term view regarding the communities in which they operate,
ScottishPower are able, via community programmes and sponsorships, to play an
important role in identifying and addressing key areas of local concern and provide
sustainable support to projects creating real and lasting benefits.
18.6.14
Section 12 presented the landscape and visual impact assessment for Damhead
Creek 2, and presented photomontages indicating that some parts of the
Development would be visible from all sides and from large stretches of the
surrounding area. However, Damhead Creek 2 will be viewed within the context of
the existing Damhead Creek CCGT Power Station and the neighbouring Kingsnorth
Power Station which is approximately 300 m to the south. Therefore, it is not
considered that Damhead Creek 2 will cause any impact on the view of the area and
it is concluded that it will be insignificant to the area’s income from tourism.
18.6.15
There will be no, unacceptable, risk to public safety in the vicinity of the plant or any
adverse effect on existing, or allocated, land uses in the area. Damhead Creek 2 will
not conflict with users of neighbouring land (see discussion in Section 5).
18.7
Mitigation
Construction
18.7.1
The construction of the proposed Development will provide jobs for the region and,
directly and indirectly, bring more money into the local economy.
18.7.2
No mitigation measures or monitoring programmes are considered to be necessary
due to the high positive socio-economic impact of Damhead Creek 2 during
construction.
Operation
18.7.3
The operation of Damhead Creek 2 will create permanent employment opportunities
and, wherever possible, establish strong local service links which would last for the
operating lifetime of Damhead Creek 2. There are no negative impacts expected on
any other aspect of the socio-economy of Medway.
18.7.4
due to the high positive socio-economic impact of Damhead Creek 2 during operation.
18.8
Construction
18.8.1
Local residents will, potentially, form a significant part of the construction workforce.
Where this is not possible, the typical contractor demographic based on previous
projects will mean that the demands made by workers from outside the area on local
public services such as health or education will be insignificant.
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SOCIO-ECONOMICS
18.8.2
There will be a moderate positive impact on local businesses. Wherever practical as
much of Damhead Creek 2 cost of £600 million will be invested within the region.
Typically up to 30% of the capital investment in a CCGT plant would be spent in the
local area and region more generally.
18.8.3
There will be a high positive socio-economic impact from the construction of
Damhead Creek 2.
Operation
18.8.4
Operation of Damhead Creek 2 will provide around 50 permanent non-seasonal jobs
for the area. The estimated operational and maintenance costs of Damhead Creek 2
will be of the order of £27 million per annum and will benefit the local economy in
terms of local capital and service expenditure, creating additional jobs amongst local
businesses.
18.8.5
The long term view to invest in community programmes and sponsorships, taken by
ScottishPower, will produce a high positive socio-economic impact helped by the
provision of development opportunities for young people, and the economy as a
whole.
18.9
18.9.1
There are two other major projects scheduled for construction in the vicinity of the
proposed Development, although at present it is likely that the construction schedules
would not overlap.
18.9.2
The construction of Kingsnorth Units 5 and 6 will represent a significant investment in
the area by E.ON helping to guarantee jobs in the power sector following the future
decommissioning of the existing Kingsnorth Power Station (Units 1 – 4). The
construction timetable is at this stage not known.
18.9.3
In addition, Goodman Developments Limited has applied for outline planning
permission for Kingsnorth Business Park, which would comprise up to 8 units of office
and warehouse space. The units would be developed over an area of 66 ha
north east of the Damhead Creek 2 site. Should the development go ahead, it is
likely to be phased dependent upon market conditions. At this time, Goodman
Developments Limited anticipate each unit taking a year to build and construction
work on more than one building unlikely.
18.9.4
These projects represent a significant investment that will serve to boost the economy
of the area and are considered to have an overall positive socio-economic effect.
June 2009
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SECTION 19
DAMHEAD CREEK 2 CARBON CAPTURE
READINESS
SECTION 19
READINESS
19
DAMHEAD CREEK 2 CARBON CAPTURE READINESS
19.1
Overview
19.1.1
ScottishPower commissioned a CCR Feasibility Study for the proposed Damhead
Creek 2 CCGT Power Station to determine its carbon capture readiness (CCR). The
CCR Feasibility Study (which accompanies this Section 36 Consent application)
concludes that the move from CCR to CCS is both technically and economically
feasible within the 35 year operating lifetime of Damhead Creek 2.
19.1.2
This Section of the ES presents a summary of the CCR Feasibility Study.
19.1.3
In addition to the above, ScottishPower has acquired a large parcel of land adjacent
to the proposed Damhead Creek 2 power station, to accommodate a Carbon Capture
facility. This is Area 3 on Figure 2.1.
19.2
Introduction
19.2.1
The European Union (EU) agreed the text of a new EU Directive on the Geological
Storage of Carbon Dioxide on 17 December 2008. This text was published as the
Directive on the Geological Storage of Carbon Dioxide (Directive 2009/31/EC) (the
"Directive") in the Official Journal of the European Union on 5 June 2009 and the
Directive will come into force on 25 June 2009. The Directive requires an amendment
to the LCPD such that Member States are to ensure that operators of all combustion
plants with an electrical capacity of 300 MW or more (and for which the construction /
operating licence was granted after the date of the Directive) have assessed whether:
Suitable storage sites for CO2 are available;
Transport facilities are technically and economically feasible; and
19.2.2
19.2.3
19.2.4
19.2.5
34
It is technically and economically feasible to retrofit for CO2 capture.
An Assessment of whether these conditions are met is then to be submitted to the
relevant competent authority. The competent authority shall then decide if the
conditions are met on the basis of the assessment and other available information.
If the conditions are met, the competent authority shall ensure that suitable space is
set aside for the equipment necessary to capture and compress CO2.
In the UK the relevant competent authority in respect of energy matters is the DECC,
and therefore they must ensure that the EU Directive is implemented. As such, in
June 2008, the UK Government published a consultation document “Towards Carbon
Capture and Storage” to seek views on the steps it could take to prepare for and
support both the development and deployment of carbon capture and storage
technologies.
A response to this consultation was published in April 2009, alongside draft Guidance
for applicants seeking Section 36 Consent for new combustion power stations at or
over 300 MWe34 (the Guidance). The Guidance aims to reflect the Governments new
CCR Policy, and is subject to an eight week consultation period ending on 22nd June
2009.
Guidance on Carbon Capture Readiness and Applications under Section 36 of the Electricity Act 1989 (DECC, 2009)
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READINESS
19.2.6
Under the new CCR Policy, and as part of a Section 36 Application, developers will
be required to submit a CCR Feasibility Study, which will include:
Demonstration that they have sufficient space on or near the site to
accommodate carbon capture equipment in the future;
An assessment into the technical and economic feasibility of retrofitting carbon
capture technology;
Proposals for a suitable area of deep geological storage offshore for the storage
of captured CO2;
An assessment into the technical and economic feasibility of transporting the
captured CO2 to their proposed storage area; and,
19.2.7
Discussion of the possible requirements for Hazardous Substance Consent
(HSC).
If granted Section 36 Consent, developers will be required to:
Retain the additional space on or near the site for the carbon capture equipment;
Retain their ability to build on that site in the future (if their application included
plans for some space needed for the capture and compression of CO2 to be
off site); and
19.2.8
Submit Status Reports to the Secretary of State for DECC on the effective
maintenance of the plant’s carbon capture readiness.
As discussed in Section 19.1 above, a separate stand-alone CCR Feasibility Study
has been prepared for Damhead Creek 2.
19.3
Carbon Capture Technology and Layout
19.3.1
There currently exist a number of carbon capture technologies and, at the time of
eventual installation, it is highly probable the number of technologies will have
increased.
19.3.2
However, in order to demonstrate immediate CCR, the CCR Feasibility Study for the
Development focused solely on the best currently available technology closest to
commercial deployment. For carbon capture from flue gases (post-combustion
capture), is chemical absorption using amine solvents. The amine solvents are
typically based on monoethanolamine (MEA), diamine or sterically hindered amine.
19.3.3
There are two main Options which are considered in the CCR Feasibility Study which
will influence the sizing of the carbon capture plant for Damhead Creek 2. In the
Study, these are referred to as Options A and B, and are related to the way steam is
generated for the carbon capture process. In brief:
Option A : Steam for the carbon capture process is taken from Damhead Creek
2.
19.3.4
Option B : Steam for the carbon capture process is generated from an auxiliary
boiler.
Modelling of Option A indicated a potential requirement for a carbon capture plant
capable of handling an approximate throughput of 7344 t/day, which converted to a
lifetime storage requirement of 70.4 Mt. Modelling of Option B indicated a potential
requirement for a carbon capture plant capable of handling a throughput of
8736 t/day, which converted to a lifetime storage requirement of 84.0 Mt. Further
details of these calculations are provided in the CCR Feasibility Study.
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READINESS
19.3.5
Based on the two Options, the CCR Feasibility Study has included two illustrative
layouts which illustrate how CCS equipment could eventually be installed on Area 3,
and how the CCS equipment could be incorporated with Damhead Creek 2.
19.3.6
As the eventual deployment of CCS will involve major infrastructure changes on site,
a separate application for Section 36 Consent will be required in the future. At this
time, a further EIA, and resulting ES, will be submitted. This will include a greater
level of detail regarding the eventual selected capture technology, transport and
storage arrangements, and will cover all the likely significant environmental impacts of
operational CCS for Damhead Creek 2. At present, these are expected to include
(amongst others) discussion of likely significant environmental impacts on:
Ecology, including those within the area set aside for the carbon capture plant
(Area 3), and in the areas surrounding the Development in terms of eventual
likely pipeline route;
Cultural Heritage, due to disturbance of ground during construction and operation
of the carbon capture plant.
Air quality, due to construction and operation of the carbon capture plant and the
reduction in emissions of carbon dioxide;
Landscape and visual, due to the construction and operation of the carbon
capture plant; and
Noise, due to the construction and operation of carbon capture plant.
19.4
Transport Corridors and Storage Areas
19.4.1
The two illustrative layouts shown in the CCR Feasibility Study each included
potential exits points for the captured CO2 from the site. In line with the Guidance,
these are shown to link to potential on shore pipeline transport corridors which
connect to potential off shore pipeline corridors. The off shore pipeline corridors
illustrate a potential route to two identified storage areas in the South North Sea
Basin.
19.4.2
The most likely identified option at present would be an on shore pipeline leaving from
the south of the carbon capture plant to a transition point on the coast. The off shore
pipeline would then potentially run along Damhead Creek into the River Medway
before turning north east past the site of the proposed Thames Array wind farm and
then turning north wards before connecting to the proposed storage sites.
19.4.3
The two identified potential storage areas in the CCR Feasibility Study are the Hewet
(L Bunter) gas field which has a capacity of 237 Mt CO2 and the Leman gas field
which has a capacity of 1203 Mt CO2.
19.4.4
Based on the potential storage requirements for Option A, 29.7 per cent of the
capacity of the Hewet (L Bunter) gas field would be required, or 5.9 per cent of the
capacity of the Leman gas field would be required.
19.4.5
Based on the potential storage requirements for Option B, 35.4 per cent of the
capacity of the Hewet (L Bunter) gas field would be required, or 7.0 per cent of the
capacity of the Leman gas field would be required.
19.4.6
Additional detailed discussion of the assessments undertaken is provided in the stand
alone CCR Feasibility Study.
19.4.7
Schedule 4 of the Electricity Works (Environmental Impact Assessment) (England and
Wales) Regulations 2000 makes clear that any technical deficiencies or lack of knowhow encountered by ScottishPower in compiling the required information should be
set out within the ES.
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READINESS
19.4.8
The lack of any currently commercially viable CCS plant of the scale that would be
required for Damhead Creek 2, as well as the uncertainty relating to the final
transportation route that would take the captured CO2 to a storage area, makes an
assessment of the likely significant environmental impacts of the plant difficult to
undertake. As such, a high level assessment has been made of the footprint of land
upon which it is estimated that CCS facility itself would be located. Where sensible
assumptions can be made as to the likely size, layout and composition of plant then
these have been made and assessed.
19.5
Assessment Summary
19.5.1
The CCR Feasibility Study presented the results of the required assessment listed
above, and demonstrated that it would be both technically and economically feasible
to retrofit CCS technology to Damhead Creek 2 within the 35 year operating lifetime.
19.6
Submission of Further Information
19.6.1
As the eventual deployment of CCS will involve major infrastructure changes on site,
a separate application for Section 36 Consent (or an equivalent consent under the
relevant legislation in force at the time) will be required upon the move from CCR to
CCS.
19.6.2
At this time, a further Environmental Impact Assessment, and resulting Environmental
Statement, will be submitted. This will cover all the likely significant environmental
impacts of operational CCS for the Development and will include a greater level of
detail regarding the eventual selected capture technology, transport and storage
arrangements.
June 2009
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SECTION 20
SUMMARY OF MITIGATION AND
MONITORING
SECTION 20
MONITORING
20
SUMMARY OF MITIGATION AND MONITORING
20.1
Summary
20.1.1
The mitigation and monitoring programmes proposed for Damhead Creek 2 are
summarised below.
20.2
Air Quality
Construction
20.2.1
Good site management practices during the construction works will help to prevent
the generation of airborne dust.
ScottishPower will require its construction
contractors to take sufficient precautionary measures to limit dust generation.
20.2.2
To ensure that atmospheric dust, contaminants or dust deposits generated by the
construction do not exceed levels which could constitute a health hazard or nuisance
to those persons working at the existing Damhead Creek CCGT Power Station, on
the Damhead Creek 2 site or living nearby a dust monitoring programme will be
carried out throughout the construction period. It is proposed that environmental
monitoring of dust be carried out at areas of excavation, the stockpiles, and various
additional locations across the Damhead Creek 2 site and at locations on the site
boundary. A trained and competent person will carry out monitoring on a weekly
basis. If dry windy weather prevails then the rate of monitoring will be increased. An
aerosol monitoring system will be used. The results will be checked against Table
20.1.
TABLE 20.1: MAXIMUM ALLOWABLE EXPOSURE LEVELS
Monitoring
location
Dust
Aerosol monitoring system
(directional, with
instantaneous read-out)
Level
Action
>1 and <5 mg/m3
Review PPE* level if >1 mg/m3
>5 mg/m3
continuously
Stop work in breathing zone
work
Review PPE level, go to level 2
respiratory protection
Monitor every 30 minutes
Site perimeter
0.2 mg/m3
Stop work
work
Site wide
Excessive dust or
odour
Further monitoring or control
measures as appropriate. All such
instances to be logged
Excavation areas
Stockpiles
Environmental Dust
Sampler (gravimetric over
fixed time period)
Visual and odour checks
*PPE - Personal protection equipment.
20.2.3
If the above values are exceeded then the rate of monitoring will be increased to four
times a day or to a level consistent with the results that have been logged and
additional remedial action as described below will be taken.
20.2.4
If a potential for dust emissions exists, for example on dry windy days, then the
following procedure will be followed:
Materials will be assessed for moisture content;
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MONITORING
If material is dry then water will be sprayed on to the working area to suppress
dust;
Excavation faces not being worked will, if required, be either sheeted or treated
with a chemical dust suppressant; and
All operatives working in areas of potential dust emission will be provided with
paper type face masks.
20.2.5
Materials deposited on stockpiles on the Damhead Creek 2 site will be closely
monitored for any possible emission of dust and if required they will be damped down,
covered or treated with a dust suppressant.
20.2.6
If finely ground materials are delivered, these should be in bag form or stockpiled in
specified locations where the material can be suitably covered.
20.2.7
All vehicles carrying bulk materials into or out of the Damhead Creek 2 site will be
covered to prevent dust emission. Minimum drop heights will be used during material
transfer.
20.2.8
Dust emission from moving construction plant and site transport will be mitigated by
the use of water bowsers, which will dampen all movement areas being utilized by
traffic.
20.2.9
A wheel washing facility will be provided adjacent to the Damhead Creek 2 site exit
and will be used by all heavy commercial vehicles leaving the Damhead Creek 2 site,
preventing the transmission of soil from the Damhead Creek 2 site to the public
highway.
20.2.10
Also a road sweeping vehicle will be employed when required during the construction
period to remove dust and dirt from all the public roads.
20.2.11
The above measures may only be necessary should the activities leading to the
greatest dust generation occur during a dry period.
20.2.12
If care is taken dust emissions will not impact on local air quality.
Operation
20.2.13
The following mitigating measures have been included in the design of Damhead
Creek 2:
The use of DLN Burners, which ensures NOx levels to be in accordance with
LCPD requirements;
The use of a fuel inherently low in sulphur; and
A stack of sufficient height and flue gases of sufficient temperature and velocity
to ensure good dispersion.
20.2.14
These measures, in combination, result in limited increases in background
concentrations of oxides of nitrogen, no emissions of particulates and negligible
emissions of sulphur dioxide, such that no further measures are deemed necessary.
20.2.15
ScottishPower will require a manufacturer’s guarantee in place to guarantee the
performance of the NOx abatement system. If NOx values are out with the guarantee
value the operation and calibration of the instrument will be checked and, if proved to
be accurate, Damhead Creek 2 will be examined and the fault corrected.
20.2.16
ScottishPower would if requested monitor ground level concentrations of NOx during
the first year of Damhead Creek 2's operation and one year beforehand. This monitor
should confirm the results of the atmospheric modelling and that the impacts of the
emissions from Damhead Creek 2 are in fact acceptable.
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MONITORING
20.2.17
Emissions will be controlled during operation in accordance with the manufacturer’s
recommendations and the limits and conditions specified in the EPR permit for the
process, taking account of the technical guidance available for this type of plant.
20.2.18
The stacks will be fitted with a continuous NOx and CO monitor. The measured value
will be recorded and displayed in the Control Room. Routine calibration checks will
be carried out as recommended by the manufacturer and as agreed with the EA. Any
other ad-hoc calibration checks required by the EA will be carried out. An oxygen
monitor will also be supplied and results from this will be used to correct the NO x
measured value to the format required by the EA. Either a moisture meter will be
provided or a mathematical correction factor based on combustion of natural gas will
be used to convert to the dry condition. The results from this stack monitoring will be
available to the public in the Public Register held by the EA.
20.2.19
Sampling points and safe access adjacent to the continuous monitoring points will be
installed.
20.2.20
Regular observation of chimney emissions will also be made.
20.3
Noise and Vibration
Construction
20.3.1
In order to keep noise impacts from the construction phase to a minimum, all
construction activities would be carried out in accordance with the recommendations
of BS 5228. In addition, the following mitigation measures would be implemented
through the Construction Environmental Management Plan (CEMP):
20.3.2
Core site working hours would be agreed with the Local Authority, and are specific to
the construction site. These are generally Monday to Saturday 07:00 to 19:00 hours.
It would be necessary to work outside these core hours for certain activities but this
would be with the prior agreement of the local authority.
20.3.3
Specific method statements and risk assessments would be required for night
working. In order to minimize the likelihood of noise complaints in such eventualities,
the contractor would inform and agree the works in advance with the Environmental
Health Officer, informing affected residents of the works to be carried out outside
normal hours. Furthermore, the residents would be provided with a point of contact
for any queries or complaints.
20.3.4
All vehicles and mechanical plant used for construction would be fitted with effective
exhaust silencers, and regularly maintained.
20.3.5
Inherently quiet plant would be used where appropriate. All major compressors would
be sound-reduced models fitted with properly lined and sealed acoustic covers which
would be kept closed whenever the machines are in use, and all ancillary pneumatic
percussive tools would be fitted with mufflers or silencers of the type recommended
by the manufacturers.
20.3.6
All ancillary plant such as generators, compressors and pumps would be positioned
so as to cause minimum noise disturbance. If necessary, temporary acoustic barriers
or enclosures would be provided.
20.3.7
ScottishPower will require its appointed contractor to minimize the impact of
construction activities through successful implementation of an agreed Construction
Environmental Management Plan (CEMP) and proper communication with local
residents.
Operation
20.3.8
While planning noise limits will be agreed with the local authority at the planning
consent stage, plant operators should aim to better these limits and reduce noise
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MONITORING
emissions as far as possible. The following measures would serve to continually
monitor and minimize the impact of noise from Damhead Creek 2:
A computer model of the proposed plant items should be produced at the
detailed design stage, to calculate the predicted noise levels at the NSR
locations, and ensure that planning limits are adhered to. Detailed design will
ensure that site noise is mitigated as far as possible, through site layout and
orientation of noisy plant items.
Since tonal or impulsive noises are considered more annoying than continuous
noise sources, plant items should be silenced or otherwise controlled through
regular maintenance to ensure no such emissions are audible at NSR locations.
A programme of continual noise monitoring, including a noise survey shortly
following the commissioning of the new plant, shall be agreed with the Local
Authority and implemented at regular intervals. The aim of these surveys shall
be to ensure that plant noise levels as measured at the agreed NSR locations do
not exceed the planning noise limits agreed with the local authority. Noise
monitoring shall be undertaken in accordance with BS 4142.
In the event of a complaint by a local resident relating to noise levels during the
operation of the Development, an investigation shall be carried out by the
operator, or a representative thereof, to determine the likely cause of the
complaint, and any available remedial measures. Where it is deemed necessary
by the Local Authority, a written report detailing these measures and their
effectiveness will be provided.
Inherently quiet plant items will be selected wherever practicable. In addition to
the noise control measures mentioned above high performance silencers should
be fitted to achieve maximum noise attenuation on plant including gas turbine
and HRSG inlets and ductwork. Acoustic lagging and low noise trims will be
fitted to all pipe-work and noise generating steam valves.
High performance acoustic enclosures should be considered for all plant items
where practicable, not overlooking smaller plant items such as compressors and
pumps.
Internal surfaces within the turbine hall should be treated to control internal
reverberant noise levels. An appropriate treatment would consist of dense
mineral wool panel behind perforated sheet steel, or a spray on cellulose fibre
treatment.
In the interest of maintaining neighbourly relations and residential amenity, the
company will give a reasonable period of notice to residents prior to any nonnormal operations that would lead to an increase in noise levels. These should
be carried out between 0900 and 1700 hours during the weekdays, wherever
possible.
When non-normal and emergency operations lead to noise levels in excess of
the agreed planning limits, the operator will inform the local authority and
residents of the reasons for these operations, and the anticipated emergency
period.
20.4
Construction
20.4.1
A Construction Environment Management Plan (CEMP) would be prepared in support
of Damhead Creek 2. The CEMP will address the following:
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MONITORING
Temporary storage of topsoil and any other material considered of value for
retention;
Temporary protection measures for vegetation and other features associated
with the site construction in accordance with current industry standards and
recognised best practice;
Design and layout of site construction areas including the location and type of
temporary security fencing and lighting;
Agreed site access routes and measures for the protection and, where
necessary, re-instatement of verges, vegetation and other landscape features on
routes used by construction traffic.
20.4.2
All areas affected by temporary site construction operations will be re-instated in
accordance with a restoration plan. The restoration plan would be agreed with
Medway Council as a condition of permission for the location of temporary site
construction areas. The restoration plan will address the following:
Method statements for the restoration of areas affected by construction to an
agreed after use and to an agreed timescale;
A Management Plan for reinstated areas to include any measures for the
vegetation establishment and planned long-term stewardship.
Operation
20.4.3
Damhead Creek CCGT Power Station and, as such, will appear as an extension to
the existing Damhead Creek CCGT Power Station.
20.4.4
A recessive colour scheme, identical to that used on the existing Damhead Creek
CCGT Power Station is to be used in order to break up the impact of the built
structures as shown on the photomontages.
20.4.5
to minimize light spread and glare off site.
20.4.6
There is existing landscape mitigation, principally on the northern perimeter of the
existing Damhead Creek CCGT Power Station. This mitigation combines shallow
mounding (up to 3 m in height) with areas of native planting. Whilst much of the
planting has established it has not achieved significant heights and has more the
character of areas of dense scrub. This mounding and planting would be effective in
screening low level plant and the security fencing in near views around the Damhead
Creek 2 site. The mounding is similar in scale and height to the flood protection bund
to the Medway estuary.
20.4.7
Landscape mitigation would be unlikely to achieve a significant reduction in the visual
impact of Damhead Creek 2. Extensive tree and shrub planting would also be out of
character with the local landscape of the Medway marshes.
20.4.8
Landscape planting can, however, be effective in reducing visual impact in near
views. It is, therefore, proposed to extend the mounding and planting associated with
the existing Damhead Creek CCGT Power Station to the northern edge of the
Damhead Creek 2 site. The extent of planting would take into account ecological
considerations and possible merging of planting with any landscape proposals
associated with the proposed Development by Goodman Developments Limited.
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20.4.9
A landscape management plan would also be prepared for all landscaped areas and
other areas of semi natural landscape associated with the Damhead Creek 2 site, in
order to ensure the successful establishment of new planting, the re-instatement of
areas disturbed during construction and habitat management and enhancement.
20.5
Ecology
20.5.1
Ecological mitigation measures that are required are often complementary to those
needed to reduce or offset impacts on other aspects of the environment. For
example, mitigation of landscape and visual impacts can often be combined with
ecological measures.
20.5.2
Within the context of the Ecological Impact Assessment, mitigation is one of a
hierarchy of measures that are undertaken to prevent or reduce adverse impacts.
Mitigation measures can include:
Avoidance / Prevention Measures
These are measures taken to avoid or prevent adverse impacts, and can include:
scheme layout or timing of site works.
Reduction / Mitigation Measures
These are measures taken to reduce adverse impacts and can include: retaining
walls and pollution interceptors.
Compensation / Offsetting Measures
These are measures taken to offset significant residual adverse impacts and are
for those measures that cannot be entirely avoided or mitigated to the point that
they become insignificant. They will include habitat creation and / or
enhancement.
20.5.3
In this Section, mitigation measures are proposed for all significant ecological impacts
on the habitats and species identified in the preceding Sections. Generic mitigation
measures include best practice methods and general principles that can be applied to
Damhead Creek 2 as a whole, and are relevant to all habitats and species. As
summarised in the opening paragraphs of this Section, prevention or avoidance of
these adverse impacts is the primary aim of ecological mitigation. If this is not
possible measures would be proposed to reduce the impact and if this is also not
possible then measures to offset the impact would be included in the mitigation
strategy.
20.5.4
It should be noted that a substantial level of mitigation has previously been
implemented by ScottishPower across a wide area and ScottishPower has
demonstrated its commitment to biodiversity through ongoing monitoring and
management of these areas for biodiversity gain with some notable successes
including the establishment of a reedbed supporting breeding marsh harrier.
20.5.5
corridor. In combination these areas effectively surround Area 3 of the Development
grassland.
20.5.6
Indeed the mitigation works undertaken and the mitigation land put aside for the
existing Damhead Creek CCGT Power Station were designed and agreed to offset
and compensate for the entire Damhead Creek Power Generation Development. In
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light of this, it is considered that the mitigation land already in existence will go some
way to offsetting impacts associated with Damhead Creek 2. Furthermore, it is
considered that opportunities for further enhancement and management of some
areas of the existing mitigation land would provide additional biodiversity gains; these
are discussed in further detail below.
20.5.7
However, it is recognised that due to the permanent loss of habitats that support
protected species it will be necessary to implement additional mitigation strategies to
offset potential impacts and ensure legal compliance. The detailed design of such
mitigation is not within the scope of this ES and will come forward in consultation with
the planning authority. However, a broad overview of the nature of such work is
provided.
Due to the legislative requirements for much of the ecological
mitigation/compensation work, detailed method statements and designs will be
required for securing protected species licences and it is at this stage the detailed
mitigation will be presented.
Generic Mitigation
20.5.8
The implementation of a Construction Environmental Management Plan (CEMP) by
the appointed contractor and the development of a Works Method Statement to
illustrate how impacts on ecology will be managed will be created. Good construction
site management will be implemented to avoid / minimise generation of excessive
litter, dust, noise and vibration. This will be controlled and monitored through the
CEMP. Measures will be implemented to avoid/minimise potential for problems such
as fuel and other chemical spills.
There will be no storage of potentially
contaminating materials in areas of hydrological sensitivity, such as in the vicinity of
the Estuary or the WCA. A Pollution Incident Response Plan will be included as part
of the CEMP to ensure that impacts from any potential accidental spills can be
reduced to a minimum.
20.5.9
In addition, the following measures to avoid impacts should be included in the CEMP:
Ensure that work compounds and access tracks etc are not located in, or
adjacent to, areas that maintain habitat value;
Establish site fencing to prevent access to areas outside working areas,
particularly in areas adjacent to features of interest/value;
Implement procedures to cover site safety issues, including storage of potentially
dangerous materials;
Provide briefings and instruction to contractors regarding the biodiversity issues
present on the site; and
Follow pollution prevention guidelines provided by the Environment Agency
(e.g., PPG 01, PPG 02, PPG 03, PPG 05 and PPG 06) to prevent pollution of
water courses from silt or chemicals.
20.5.10
To reduce construction impacts the following will be implemented:
Restrict workforce to working areas through the erection of fencing, to prevent
additional damage;
Best practice methods would be followed throughout; and
Establish protocols and contingency plans for dealing with incidents should they
arise.
20.5.11
It is considered that the establishment of the CEMP with the incorporation of the
above key principals will directly offset the construction impacts of Damhead Creek 2
in terms of disturbance and habitat degradation for a number of the VERs for which
significant environmental impacts have been identified.
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Specific Mitigation of Impacts to VERs
Medway Estuary and Marshes SPA/Ramsar/SSSI
20.5.12
The potential disturbance effects to the estuary can be reduced in a number of ways.
Wherever possible timing of works outside of the wintering period will effectively
reduce disturbance effects to a negligible level however it is unlikely to be realistic to
implement such a strategy over a three year construction schedule. As such the
works programme should consider the scheduling of the most disturbing activities
(subject to consultation) to coincide with periods of low waterbird activity.
20.5.13
To further reduce visual impacts throughout all periods of construction activity in
Area 3, a visual screen could be established. To some extent the estuary is already
screened from this area by an earth/spoil bank. However, it is considered that the
installation of a semi permanent soil (or similar) bank (which could also be developed
for additional species mitigation), would substantially reduce the likelihood of
disturbance (principally visual and noise) to a negligible magnitude and as such offset
the impacts identified for this VER during the construction stage.
Water Bodies
20.5.14
Aside from providing a valuable ecological feature, the water bodies within the
Damhead Creek 2 site provide an important hydrology function (as discussed in
Section 15). As such, some of the water bodies in Area 3 that will be permanently
lost during construction will be compensated for on at least a 1:1.25 ratio in terms of
volume of water and length of bank side habitat.
20.5.15
The specific design and location of these replacement water bodies will be subject to
a detailed mitigation strategy and method statement. However the broad features of
the design and development include,
Established at least 1 year in advance of other water bodies being removed;
Located in areas that will not be subject to further development and /or impacts
from nearby development operations (including the proposed development);
Connected with existing water bodies and habitats;
Appropriate bank side profiles and planting to provide optimal habitat for water
voles;
Translocation of some plants and species (principally invertebrates) from water
bodies subject to loss; and
Long term management prescriptions (as part of an overarching ecological
management plan) to maintain their ecological value.
20.5.16
It is considered that the establishment of these water bodies with the incorporation of
the above key principals will directly offset the construction impacts of Damhead
Creek 2in terms of permanent habitat loss for several VERs and result in impacts of
negligible magnitude and as such not significant.
Badger
20.5.17
By implementing the mitigation set out for prevention and avoidance of impacts
detailed in the generic mitigation section above, it is considered that the potential
disturbance effects to badgers during the construction period are offset to result in
any effects being not significant.
20.5.18
Risks of mortality to badgers can be offset by management of site traffic in terms of
speed limits and routes and by ensuring trenches and pits are covered or include a
crawl board at night when badgers would be active. It is considered that these
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measures would provide sufficient mitigation to reduce any impacts to badgers as not
significant.
Water Vole
20.5.19
Water voles and their habitat are protected under the Wildlife and Countryside Act
1981 (as amended). As such, without mitigation the impacts identified for this species
arising from the construction activities would potentially result in a legal offence being
committed.
20.5.20
In essence the legislation does not permit licences to be issued in relation to
development of land. Therefore it will be necessary to demonstrate that Damhead
Creek 2 has considered all options available in order to avoid the need for removal of
water vole habitat in Area 3 within the Damhead Creek 2 site.
20.5.21
Guidance from Natural England35 identifies that the capture of water voles for
translocation from a site is unlikely to be considered the "incidental result of other
activities" and so is not covered by the defence in the recently revised legislation.
However, if despite all reasonable efforts, properly authorised development will
adversely impact on water voles and there are no alternative habitats nearby, Natural
England may be able to issue a licence to trap and translocate water voles for the
purpose of conservation. In order to issue such a licence, Natural England would
need to be assured that there is no reasonable alternative to the development or
maintenance work and that there are no other practical solutions which would allow
water voles to be retained at the same location. Natural England will need to be
assured that the mitigation strategy and compensation will result in a positive
contribution to water vole conservation.
20.5.22
Accordingly, to ensure that potential impacts to water voles are avoided and to ensure
compliance with the legal requirements, in conjunction with the development of new
habitat (as outlined above), it will be necessary to undertake updated surveys
between 12 and 24 months prior to construction to fully assess the water vole status
within the affected areas (and within an appropriate zone of influence), devise a
detailed mitigation plan and method statement specific to this species documenting
the habitat compensation and a translocation methodology following the best practice
outlined in Strachen & Moorhouse (2007) 8. It is proposed that pre-construction
update surveys will be completed post consent.
20.5.23
By ensuring that the outline guidance presented above is implemented it is
considered that the identified significant impacts to water voles would be offset and
the construction activities would be legally compliant in regard to the protection
afforded to water voles.
Bats
20.5.24
Construction and operational lighting will, wherever possible, utilise low pressure
sodium lamps or high pressure sodium instead of mercury or metal halide lamps.
Lighting will be directed to where it is needed and light spillage avoided. This will be
achieved by the design of the luminaire and by using accessories such as hoods,
cowls, louvres and shields to direct the light to the intended area only.
20.5.25
With the additional water body compensation it is considered that the identified
potential negative effects to bats will be of negligible magnitude and not significant.
Birds
20.5.26
35
To comply with the legal protection afforded to breeding birds, the clearance of any
breeding habitat will need to be undertaken outside of the breeding season (March to
Water voles – the law in practice Guidance for Planners and Developers. Natural England 2008
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September). In the event this is not feasible, a nest check survey will be required to
identify the absence of breeding birds before habitat clearance can be implemented.
20.5.27
In line with other VERs as per below, the site wide mitigation measures will ensure
that optimal breeding habitat for the species assemblage is maintained across the
Damhead Creek 2 site. This will include nesting habitat, foraging habitat and
appropriate winter habitat. Given the relatively small areas of optimal breeding bird
habitat that will be lost it is considered that this mitigation is appropriate to offset the
potential negative effects to breeding birds.
Reptiles
20.5.28
A Mitigation Strategy for reptiles will be prepared that ensures potential impacts to the
species are minimised and that the construction activities comply with the legal
obligations required. The strategy will be developed to compliment mitigation for
great crested newts (as set out below).
20.5.29
It is considered that based on the existing condition and management of some areas
of the mitigation land, principally grassland areas, there is scope to provide
enhancement and increase the suitability of the habitats to support flora and fauna
through adaptation of the management plan and some additional activities.
20.5.30
Due to the permanent loss of reptile habitat, areas of sub optimal habitat within the
existing mitigation land (including some areas of the WCA) will be adapted/enhanced
to provide compensatory habitat for reptiles. Areas identified that could be enhanced
include sections of the WCA grassland areas, sheltered areas of the coastal corridor
(primarily to the south west) and some of the grassland areas on the north west
Exclusion area. In addition to the existing mitigation land there is scope to enhance
the bund between the WCA and Area 3 on the north eastern side. At present this
bank is of very limited conservation value and has the potential to be developed into
suitable habitat that will also be beneficial in increasing the width and functionality of
the corridor features that the mitigation area provides.
20.5.31
The ways in which the habitats can be further enhanced include appropriate earth and
vegetation management to provide optimal reptile conditions and the creation of
reptile hibernacula. For example by altering the current mowing regime and adopting
a multi-rotational cutting of the coastal grasslands would create a mosaic of different
sward heights that would provide both, basking, foraging and shelter habitats for
reptile species. Increased, managed, scrub development in the grassland areas
would also provide increased areas of shelter, and where flowering species are
concerned, increased invertebrate fauna for foraging reptiles.
Mitigation
enhancement will also consider opportunities for topographical alterations and
adapting banks and bunds to provide a physical increase in the total area of suitable
reptile habitat available thereby increasing the carrying capacity.
20.5.32
These activities will be undertaken to ensure continued connectivity across the
Damhead Creek 2 site and beyond.
20.5.33
reptiles would be of negligible magnitude and as such not significant.
Amphibians
20.5.34
A Mitigation Strategy for great crested newts will be prepared that ensures potential
impacts to the species are minimised and that the construction activities comply with
the legal obligations required.
20.5.35
Given the apparently limited distribution of great crested newts across the Damhead
Creek 2 site, it is considered that terrestrial habitat is not likely to be the limiting factor
on this population and that the WCA provides sufficient habitat for the existing
population and allowance for population growth.
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20.5.36
As the WCA was, in part, created for the specific purpose of great crested newt
habitat compensation for the Damhead Creek Power Generation Development and
will be retained under the development of Damhead Creek 2, it is considered that it
should be possible to exclude the WCA, and as such the great crested newts, from
the Damhead Creek 2 site under a permitted licence from Natural England without the
need for a translocation scheme. As a result of these actions it is considered that the
potential negative impacts to great crested newts would be of negligible magnitude
and as such not significant.
20.5.37
In line with the proposed habitat enhancement works to the existing mitigation land,
the enhancement provisions will be of benefit to terrestrial invertebrates, in part to
ensure a food source for herpetiles. Specific enhancement would be targeted to the
key species identified during the monitoring and survey work and is considered
appropriate to offset the impacts identified for terrestrial invertebrates.
20.5.38
The establishment of replacement water bodies to offset those being lost will largely
offset the negative impacts identified for aquatic invertebrates. Translocation of
aquatic invertebrates into the new water bodies will further ensure the long term
viability of this VER. As a result of these actions it is considered that the potential
negative impacts to aquatic invertebrates would be of negligible magnitude and as
such not significant.
20.6
Water Quality
Construction
20.6.1
The British Standard Code of Practice for Earthworks BS 6031:1981 contains detailed
methods that should be considered for the general control of drainage on construction
sites. Further advice is also available in the British Standard Code of Practice for
Foundations BS 8004: 1986. These will be taken into account in the design and
20.6.2
Mitigation measures during construction will include, as appropriate:
Any oil storage tanks to be located on an impervious base provided with bund
walls to give a containment capacity of at least 110 per cent of the tank volume.
All valves and couplings to be contained within the bunded area.
Any surface water contaminated by hydrocarbons, which are used during the
construction phase, to be passed through oil/grit interceptor(s) prior to discharge.
Measures will be taken to ensure that no leachate or any surface water that has
the potential to be contaminated is allowed to enter directly or indirectly into any
water course, underground strata or adjoining land.
Provisions to be made so that all existing drainage systems continue to operate.
Water inflows to excavated areas to be minimised by the use of lining materials,
good housekeeping techniques and by the control of drainage and construction
materials in order to prevent the contamination of ground water. Site personnel
to be made aware of the potential impact on ground and surface water
associated with certain aspects of the construction works to further reduce the
incidence of accidental impacts.
Refuelling of construction vehicles and equipment to be restricted to a
designated area with properly designed fuel tanks and bunds and proper
operating procedures.
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Operation
20.6.3
The Environment Agency (EA) will set limits on the quality of water that is discharged
from the Damhead Creek 2 site under the Environmental (EPR) Permit. Southern
Water will be consulted concerning any discharge to the sewer as this will require a
separate trade effluent discharge licence.
20.6.4
All aqueous process effluents will be discharged to the Damhead Creek via the
existing drainage system and will be in accordance with EA limits already in existence
for the existing Damhead Creek CCGT Power Station. The existing drainage system
already includes interceptors to ensure oily water does not escape from the site. No
further on-site treatment will be necessary as the aqueous process effluents are
effectively pure water. This represents the best practicable environmental option for
these effluents and is consistent with the approach suggested in Chapter 2 of the
EA’s PPC combustion Sector Guidance Note V2.03.
20.6.5
The water treatment plant effluent will be monitored for pH value. If the pH is out with
the limit of 6 to 9, or outside any limit permitted by the EA, the discharge will
automatically stop until the failure is corrected.
20.6.6
The use of de-icing substances will be minimised during the winter.
20.6.7
All oil and chemical storage tanks and areas where drums are stored will be
surrounded by an impermeable bund. Single tanks will be within bunds sized to
contain 110 per cent of capacity and multiple tanks or drums will be within bunds
sized to contain 110 per cent of the capacity of the largest tank. Permanently fixed
taps, filler pipes, pumping equipment, vents and sight glasses will also be located
within the bunded area. Taps and valves will be designed to discharge downwards
and will be shut and locked in that position. Manually started electrically operated
pumps will remove surface water collected within the bund and its composition will be
verified prior to disposal.
20.6.8
unlikely to be contaminated with oil due to their location and discharge the water to
the storm water drainage system. The majority of the surface water drainage will be
uncontaminated and typical of surface water run off from paved areas or roads. The
potential for contamination is minimal and associated with areas around storage
vessels which will be appropriately bunded.
20.6.9
An oily waste water drainage system will drain all areas where oil spillages could
occur. The design will incorporate oil interceptors and traps. These will discharge
with the other surface water discharge to the storm water discharge system. The
discharge from each oil interceptor will contain no visible oil or grease.
20.6.10
20.6.11
20.6.12
Damhead Creek 2 will be designed to take into account the flood risks associated with
the Damhead Creek 2 site. These are fully outlined in the Flood Risk Assessment
prepared for Damhead Creek 2, which is available in Appendix H. Mitigation
measures that would be incorporated in the design of the Damhead Creek 2 site will
include the bunding / elevation of equipment that could cause contamination to water
and all equipment at the Damhead Creek 2 site sensitive to water exposure.
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20.7
Geology Hydrology and Land Contamination
Construction
20.7.1
During construction, all spoil will be stockpiled away from surface water and freshly
excavated areas. A minimum distance of stockpiles from surface water will be agreed
with the EA and construction contractors. Data from Phase 2 Intrusive Site
Investigations (Terra Tek Ltd. 2007; PB Ltd. 2009) suggests that the sites are not
heavily contaminated. Therefore if there is any run-off from stockpiles this is likely to
be uncontaminated. However, to prevent suspended sediments entering surface
water, exposed areas of soil will be kept to a minimum and any exposed soil will not
be left uncovered for long periods of time. In addition, surface run-off will be pumped
or drained off the site via a silt trap, minimising any potential impacts.
20.7.2
In order to limit disturbance and mixing between soils, groundwater and surface water
during construction, the construction area will be delineated and no vehicle use will be
undertaken outside the working boundary, other than on hardstanding or access
roads. In order to further limit disturbance, any additional site access roads required
will be constructed prior to the commencement of any excavations on the Damhead
Creek 2 site.
20.7.3
Current access roads will be used for the Damhead Creek 2 site. These roads have
been constructed with an appropriate camber and drainage system so as to manage
heavy rainfall and associated run-off. If any new access roads are required, they will
be constructed to a similar standard, so as to manage any additional run-off which
occurs.
20.7.4
Precautions will be undertaken to ensure the protection of the watercourses in the
vicinity of the Damhead Creek 2 site (River Medway and Damhead Creek). No
substance or drainage will be discharged to surface water unless agreed with the EA
and in accordance with the relevant discharge consent. In addition, pollution
prevention measures such as compliance with PPG 10 and The Control of Pollution
(Oil Storage) (England) Regulations 2001, will be used on site to prevent any
contamination of the groundwater.
20.7.5
A temporary wheel washing facility will be installed to prevent transfer of soil onto
nearby public roads.
20.7.6
Excavation and foundation construction would be conducted in a manner that will
minimise the size and duration of the excavated area.
20.7.7
Dust suppression measures, such as dowsing stockpiles with water, will minimise
dust levels on the Damhead Creek 2 site and in the surrounding environment
(minimising the potential of inhalation of contaminants). Further details are provided
in Section 10 of this ES.
20.7.8
All manual workers will be required to wear appropriate PPE during the construction
phase and strict hygiene measures will be adopted. Unsupervised man entry into
excavations will not be permitted.
20.7.9
The contractor will provide a silt trap and/or oil interceptor(s) at a location(s) agreed
with the Environment Agency to allow solids or immiscible liquids to settle/separate
prior to discharge. The contractor will inspect, empty and maintain any silt traps /
interceptors which are installed. A registered waste carrier will remove all sludges or
residues collected during cleaning operations off site to a suitably licensed waste
disposal facility.
20.7.10
Any pumping of water from excavations will be undertaken at such a rate using an
appropriately sized pump in order to avoid unnecessary disturbance or erosion. The
location of dewatering pipework will be carefully positioned to minimise the risk of
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damage to underlying geology. The contractor will regularly inspect all dewatering
pumps, pipe work and connections.
20.7.11
The British Standard Code of Practice for Earthworks (BS 6031:1981) contains
detailed methods that would be considered for the general control of drainage on
construction sites. Further advice is also available in the British Standard Code of
Practice for Foundations BS 8004:1986. These will also be taken into account.
20.7.12
The compaction of the soils will be minimised by restricting vehicle movements to
specified routes and construction areas by segregating construction areas from other
sites. In addition, a temporary site compound will be constructed for the parking of
construction vehicles and equipment, staff vehicles, and the storage of materials.
20.7.13
Storage of fuel would be limited and secure. Temporary diesel storage tanks will be
double skinned or contained with an impermeable bund, capable of holding 110 per
cent of the tank’s contents. Oil will be stored in accordance with The Control of
Pollution (Oil Storage) (England) Regulations (2001).
20.7.14
Construction machinery will be checked regularly to prevent oil leaks or other
emissions from faulty operation. Maintenance of construction machinery will not be
allowed on the Damhead Creek 2 site, which will help to prevent the accidental
leakage of lubricating and hydraulic fluids. Refuelling will be limited to a designated
area, on an impermeable surface, at a sufficient distance away from any drains or
watercourses (this distance may need to be discussed between the EA and
contractors). Spill kits, absorbent geotextiles and absorbent sands will be available
on the Damhead Creek 2 site at all times, in accordance with The Control of Pollution
(Oil Storage) (England) Regulations (2001) and PPG 10. Any spills will be cleaned up
as soon as possible, according to the spill response plan which will be prepared for
the site, with any contaminated sands bagged up and disposed of correctly.
20.7.15
Parking of staff vehicles and equipment will only be permitted in designated areas.
20.7.16
Throughout the works, the Waste Management "Duty of Care" and the Hazardous
Waste (England and Wales) Regulations 2005 (as amended) and all other relevant
waste legislation will be strictly adhered to, including the collation of all required
paperwork (such as waste transfer notes and consignment notes) and checking of
transport and disposal contractors.
20.7.17
Spoil generated on the Damhead Creek 2 site will be stockpiled, tested for waste
acceptance criteria and geotechnical composition if necessary and removed off the
Damhead Creek 2 site by a waste contractor by appropriate means or re-used on
Damhead Creek 2 site to fill excavations, if permitted. The excavated spoil will be
split into two categories for handling: ‘contaminated’ and ‘uncontaminated’. This
distinction will be determined from the results of samples taken from trial pits and
other prior investigations to show the quality and quantity of excavated material.
20.7.18
The physical division between the two categories of spoil will be made before it is
removed from the Damhead Creek 2 site. Hazardous Waste and excavated spoil and
materials that are classified as giving rise to an environmental hazard will be disposed
of at a suitably licensed waste disposal site. Vehicles carrying wastes would be
suitably licensed and sheeted / netted or appropriately covered to prevent the escape
of waste materials en route.
20.7.19
All works will be undertaken with reference to the Waste Management Duty of Care,
imposed by Section 34 of the Environmental Protection Act (1990) and the Hazardous
Waste (England and Wales) Regulations (2005).
20.7.20
Where spoil is not contaminated, the approach will be to adopt a disposal hierarchy,
with the first choice option being to re-use spoil on site as part of Damhead Creek 2
project wherever possible. The second choice would be to reuse spoil in other
developments taking place within the locality of the Damhead Creek 2 site, however,
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it is unlikely that the majority of the spoil will be required as part of the construction
works on Damhead Creek 2 site. If these are not possible, the final choice will be for
removal of the waste spoil from the Damhead Creek 2 site for disposal by a suitably
licensed contractor.
Installation of Foundations
20.7.21
Piled foundations are likely to be necessary due to the poor soil conditions underlying
the Damhead Creek 2 site (i.e., areas of soft clay and underlying granular soils).
Further details of the recommended foundations for Damhead Creek 2 are given in
the Phase 2 site investigation report (Terra Tek ltd. 2007) which has been reproduced
in Appendix I of this ES.
Operation
20.7.22
No areas of the Damhead Creek 2 site will be accessible to the general public.
Therefore, members of the general public are not considered to be at any risk from
contaminants on the Damhead Creek 2 site and no further mitigation measures are
considered to be necessary.
20.7.23
A full Environmental Management Plan (EMP) with training will be delivered to the
operational staff of the plant to ensure that all potentially contaminating materials are
handled correctly and cleaned up effectively if any spillages take place.
20.7.24
Disposal of all waste materials will be via appropriately licensed disposal contractors.
20.8
Traffic and Infrastructure
Construction
20.8.1
It is anticipated that all deliveries will be brought to site via Junction 1 of the M2, the
A289 and the A228. The use of the A289 bypasses local town centres to eliminate
avoidable congestion. ScottishPower will encourage car sharing and the provision of
a minibus service by contractors so as to reduce the number of vehicles visiting the
construction site.
20.8.2
All vehicle movements associated with the construction of Damhead Creek 2 will
operate under a Transport Management Plan (TMP). The purpose of the TMP will be
to actively manage, in full consultation with the Highways Agency and Medway
Council, all potential issues resulting from the increased demand on the local
20.8.3
As part of the TMP review process, the Transport Manager will discuss all relevant
issues with all users of the Kingsnorth Business Park to establish the scope for the
provision of shared traffic management services. These discussions will also help to
identify any potentially significant cumulative impacts on the local transport
infrastructure and define appropriate mitigating measures that could be mutually
beneficial.
20.8.4
Construction contractors will be required to survey all routes to ensure that any
abnormal load can be transported to site by road with the least inconvenience to other
road users.
The contractors will be responsible for the cost of any route
strengthening requirements. Routes and timings of the transportation of abnormal
loads will be discussed with the relevant authorities in order to minimise disruption. A
police escort may also be used.
Operation
20.8.5
No perceivable impact is expected during the operation of the proposed Development
and no mitigation methods are deemed necessary.
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20.9
Cultural Heritage
Construction
20.9.1
The assessment has concluded that the impact of the proposed Development on
archaeological and palaeo-environmental remains will be slight-moderate adverse
without mitigation.
20.9.2
It is clear that the nature and survival of the archaeological resource on the Damhead
Creek 2 site is not fully understood at this stage. For this reason it is proposed that an
archaeological watching brief is employed at the Damhead Creek 2 site during the
construction stage of the project. Furthermore it is recommended that once the impact
of the development of Damhead Creek 2 is finalised, archaeological trial trenching
should be carried out within areas of construction impact. Further sampling of the
palaeo-environmental deposits may be required, although some mitigation of this
resource has already been carried out by previous investigations on the Damhead
Creek 2 site.
20.9.3
The extent of mitigation works would be agreed with Medway Council once the
proposed Development has been finalised and the extent of impact can be
ascertained. The results of the initial trenching work may lead to a requirement for
further mitigation works such as excavation.
Operation
20.9.4
A requirement for archaeological mitigation during the operational phase of Damhead
Creek 2 is not anticipated. De-watering of peat or alluvial deposits may occur after
construction and should be monitored.
20.10
Socio-Economics
Construction
20.10.1
The construction of the proposed Development will provide jobs for the region and,
directly and indirectly, bring more money into the local economy.
20.10.2
due to the high positive socio-economic impact of Damhead Creek 2 during
construction.
Operation
20.10.3
The operation of Damhead Creek 2 will create permanent employment opportunities
and, wherever possible, establish strong local service links which would last for the
operating lifetime of Damhead Creek 2. There are no negative impacts expected on
any other aspect of the socio-economy of Medway.
20.10.4
due to the high positive socio-economic impact of Damhead Creek 2 during operation.
June 2009
Page 334

damhead creek 2 environmental statement

Transcription

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