- Municipality of Meaford

Transcription

MUNICIPALITY OF MEAFORD
REPORT ON
SANITARY SEWER COLLECTION SYSTEM
MODEL UPDATE
MUNICPALITY OF MEAFORD
REPORT ON
SEWERCAD MODEL
2010 UPDATE
Ainley & Associates Limited
Consulting Engineers and Planners
280 Pretty River Parkway
Collingwood, Ontario
L9Y 4J5
Tel:
Fax:
(705) 445-3451
(705) 445-0968
File No. 109119
February 2013
MUNICPALITY OF MEAFORD
REPORT ON
SEWERCAD MODEL
2010 UPDATE
1.0
INTRODUCTION ............................................................................................. 1
1.1
2.0
AUTHORIZATION............................................................................................. 1
SUMMARY ........................................................................................................ 1
2.1
2.2
2.3
2.4
2.5
3.0
TERMS OF REFERENCE ................................................................................ 1
STUDY AREA ................................................................................................... 1
REVIEW OF PREVIOUS REPORT ................................................................... 2
SOILS AND GEOLOGY .................................................................................... 2
SEWER USE BY-LAW ...................................................................................... 2
EXISTING SANITARY SEWAGE COLLECTION SYSTEM ........... 3
3.1
3.2
3.3
GENERAL......................................................................................................... 3
SANITARY SEWERS ....................................................................................... 3
SEWAGE PUMPING STATIONS ...................................................................... 3
3.3.1
3.3.2
3.3.3
3.3.4
3.3.5
4.0
SEWAGE PUMPING STATION NO. 1 (BIGHEAD RIVER) ...................................... 3
SEWAGE PUMPING STATION NO. 2 ...................................................................... 4
ASSESSMENT OF SEWERAGE SYSTEM.......................................... 5
4.1
4.2
4.3
FLOW ANALYSIS ............................................................................................. 5
FIELD INVESTIGATION ................................................................................... 5
HYDRAULIC ANALYSIS ................................................................................... 5
4.3.1
4.3.2
4.3.3
2004 MODEL ............................................................................................................. 6
2010 MODEL ............................................................................................................. 6
2030 MODEL ............................................................................................................. 7
5.0
REHABILITATION ALTERNATIVES...................................................... 7
6.0
APPROVALS ................................................................................................... 7
6.1
6.2
ENVIRONMENTAL ASSESSMENT .................................................................. 7
MOE CERTIFICATE OF APPROVAL ............................................................... 7
7.0
PROPOSED FUTURE DEVELOPMENT ............................................... 8
8.0
CONCLUSIONS AND RECOMMENDATIONS ................................... 9
8.1
SEWER MAINTENANCE PROGRAMME ......................................................... 9
8.2
PRIORITIZATION OF REHABILITATION ......................................................... 9
8.3
JUSTIFICATION ............................................................................................... 9
8.4
CATCHBASINS ................................................................................................ 9
8.5
STORM SEWER CONNECTIONS .................................................................. 10
8.6
MAINTENANCE HOLES ................................................................................. 10
8.7
FLOW MONITORING ..................................................................................... 10
8.8
SEWAGE TREATMENT PLANT UPGRADES ................................................ 10
8.9
SEWER SYSTEM (AS MODELLED IN 2004) ................................................. 10
8.10
EXISTING SYSTEM (2010) ............................................................................ 11
8.11
ULTIMATE
SYSTEM
(2030)…………………………………………………………………11
9.0
9.1
9.2
9.3
9.4
9.5
CAPITAL COST ESTIMATE (20 YEAR PHASING)
...................... 13
IMMEDIATE UPGRADES ............................................................................... 13
2015 UPGRADES ........................................................................................... 13
2020 UPGRADES ........................................................................................... 14
2025 UPGRADES ........................................................................................... 14
2030 UPGRADES ........................................................................................... 15
APPENDICES
APPENDIX A:
SEWER USE BY-LAW
APPENDIX B1: SANITARY SEWER ELEMENTS
APPENDIX B2: UPGRADES & ADDITIONAL DEVELOPMENT
BETWEEN 2004 TO 2010
APPENDIX C:
FLOW ANALYSIS
APPENDIX D:
2004 FIELD INVESTIGATION
APPENDIX E:
FUTURE DEVELOPMENT
Municipality of Meaford
Update
1.0
INTRODUCTION
1.1
AUTHORIZATION
Sanitary Sewer Collection System
SewerCAD Computer Model 2010
On August 11, 2009, Ainley and Associates Limited was retained by the Municipality of Meaford
to update the 2004 SewerCAD model for the Meaford urban area (former Town of Meaford).
The purpose of the update is to identify specific hydraulic capacity deficiencies within the
existing sanitary sewage collection system. In addition, future hydraulic capacity deficiencies
resulting from proposed developments and the new official Plan are to be identified.
2.0
SUMMARY
In 2004, Ainley Group completed a computer hydraulic model of the Meaford sanitary sewer
collection system using SewerCAD, a computer software program developed by Haestad
Methods. The SewerCAD model identified several hydraulic capacity issues within the existing
sanitary sewage collection system. However, the majority of recommended works were related
to the replacement of aging infrastructure that had exceeded its useful service life. Furthermore,
known anticipated sanitary sewage flows from proposed developments and potential growth
identified in the municipality’s Official Plan were input into the SewerCAD model to identify
hydraulic deficiencies and needs to accommodate this growth. The growth period examined was
to 2023.
This SewerCAD sanitary sewage collection system model builds upon the 2004 model. It
incorporates system improvements and development from 2004 to 2010 to represent the
existing 2010 condition. Inputting the latest Official Plan and Zoning By-law development
potential and, where available, specific proposed development plans modelled future (2030)
conditions.
The modelling results indicate that the existing sanitary sewage collection system has sufficient
hydraulic capacity to accommodate the proposed growth with the planning horizon of 2023
indicated in the municipality’s Official Plan.
2.1
TERMS OF REFERENCE
The terms of reference for this report are summarized as follows:
•
Collect data for existing sewer system inventory from Municipality of Meaford.
•
Collect Operating reports including Meaford Sewage Pumping Stations Flow Data from
2006 to 2010 from Municipality of Meaford.
•
Compile an up-to-date system inventory based on all above data.
•
Identify existing system deficiencies.
•
Update the existing 2004 SewerCAD computer model (using SewerCAD software as
supplied by Haestad Methods of Waterbury Connecticut) to prepare a 2010 existing
conditions model and a 2030 SewerCAD future growth model.
•
Prepare a model update report.
2.2
STUDY AREA
The area considered in this study is that shown overleaf in Figure 1.
March 2011
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Update
2.3
REVIEW OF PREVIOUS REPORT
A review of the previous report on Meaford’s sanitary sewer collection system model prepared
by Ainley Group in October 2004 provided valuable background information.
The areas of structurally deficient sanitary sewers and many point sources of extraneous flows
were identified through a Sewer Needs Study conducted by Ontario Ministry of the Environment
prior to 2004. Following that, a list of the deficiencies and a proposed schedule for their
correction were presented in Ainley’s 2004 report.
Correction of these deficiencies resulted in a reduction in average flow. In turn, this has allowed
for continued growth in the area during the design, approval and completion of Meaford’s
Sewage treatment plant expansion.
2.4
SOILS AND GEOLOGY
The underlying bedrock of the Meaford area is classified as grey shale, with limestone interbeds
of the Georgian Bay Formation, formed during the Upper Ordination period (Ontario Division of
Mines Map 2254 “Paleozoic Geology of Southern Ontario”).
Two soil groups predominate the study area, the grey brown podzolic soils, Brighton series and
the brown forest grey brown podzolic intergrade soils, Kemble series (Agriculture Canada map
entitled “Soils of Grey County, North Sheet, Ontario, Soil Survey Report No. 17).
The Brighton series soil is found south of Meaford Creek and west of the remnant shoreline of
postglacial Lake Algonquin. This soil series is typically well-sorted, sandy outwash, with sandy
surface texture. The typical profile consists of 75 mm dark grey sandy loam over 25-35 mm
yellow brown sand over 50-75 mm reddish brown sandy loam over grey calcareous sand. The
area has a gently sloping topography and an essentially stone free surface. The drainage
characteristics are good. The newer subdivisions and the hospital are generally located on this
soil series.
The Kemble series soil is generally bounded by the Brighton series soil to the west and by
Georgian Bay to the east. This soil series is typically fine-textured and derived from limestone
till with a silty clay surface texture. The typical profile is 130-150 mm of very dark grey clay loam
over 75-100 mm yellow-brown clay loam over yellow calcareous till. The area has a smooth
gently sloping topography and a moderately stony surface. The drainage characteristics are
imperfect. The downtown and older areas of Meaford are generally located on this soil series.
2.5
SEWER USE BY-LAW
By-Law No. 54-78, passed on January 2, 1979, regulates the use of the sanitary sewage
collection system.
The by-law provides for the control of sanitary sewage quality, permits and fees for service
connections and specifications for materials and construction of service connections.
The by-law prohibits the discharge of “storm water, water from drainage of roofs or land, or from
a watercourse, of uncontaminated water; except that which may be discharged into a combined
sewer;” into the sanitary sewage collection system. A copy of By-Law No. 54-78 can be found
in Appendix A. This by-law is significantly out of date. It is recommended that the Municipality
review the By-Law and update as necessary.
March 2011
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Update
3.0
EXISTING SANITARY SEWAGE COLLECTION SYSTEM
3.1
GENERAL
The majority of Meaford urban area is serviced by a municipal sanitary sewer system consisting
of a network of gravity sewers and five sanitary sewage pumping stations. A major portion of
the flows, approximately 80 percent, is directed to a centrally located main pumping station
(SPS No. 1), known as the Bighead River sewage Pumping Station on the south side of the
Bighead River.
A small, more recently developed area in the northeast section of Meaford is serviced by a local
pump station (SPS No. 3). However, all the flow generated from the north side of the Bighead
River, including the flows from SPS No. 3, pass through an inverted siphon located at the corner
of Berry Street and Bayfield Street into SPS No. 1.
The southeast section of Meaford is serviced by a pump station located at the Water Pollution
Control Plant site (SPS No. 2).
Two small pump stations (SPS No. 4 and SPS No. 5) service limited collection areas. SPS No.
4, located at the east end of Boucher Street services Stanley Knights Limited and a few homes.
While SPS No. 5 located on St. Vincent Street services the Canadian Coast Guard and Harbour
Masters Offices as well as some washrooms located at the Marina.
An overall plan of the sanitary sewer collection system and pump station locations is included in
the set of drawings with this report.
3.2
SANITARY SEWERS
An inventory of the sanitary sewer system structures was compiled as part of this study in order
to construct the SewerCAD model of the system. Two spreadsheets, one of the gravity pipe
sections and another of the maintenance holes are included in Appendix B1. The spreadsheets
list all of the as-built information that was collected from the available record drawings.
One new spreadsheet detailing new gravity pipe sections and new maintenance holes from the
sanitary sewer system additions and upgrades is included in Appendix B2. This spreadsheet
lists all of the as-built information that was collected from the recent available record drawings.
This overall system comprises approximately 35,080 m of gravity sewer pipe and approximately
2,140 m of forcemain.
3.3
SEWAGE PUMPING STATIONS
3.3.1
SEWAGE PUMPING STATION NO. 1 (BIGHEAD RIVER)
Sewage Pumping Station No. 1, also known as the Bighead River Pumping Station is located
east of Sykes Street and South of the Bighead River. A double barrel inverted siphon connects
the area north of the Bighead River to the pump station.
This station was reconstructed in 1991 (Ministry of the Environment Certificate of Approval No
3-0388-89-006) and consists of a reinforced concrete wet well divided into two compartments by
a common wall. It is equipped with two submersible pumps with fixed speed and two
submersible pumps with variable speed capabilities, for a total firm capacity of 181 L/s against a
total dynamic head (TDH) of 51 m with any three pumps operating in parallel. The pumps are
Flygt model CP3300 and are 88 HP each.
The station also includes a below grade reinforced concrete control building structure housing a
standby diesel generator, fuel supply, flow meter, all associated piping, heating, ventilation,
electrical and control system.
March 2011
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Update
There is a 600 mm diameter overflow pipe with provision for installing chlorination equipment to
disinfect any raw sewage overflows to Bighead River.
A 300 mm diameter forcemain connects the Bighead River pumping station to the WPCP
located on Grant Avenue in the south west end of Meaford.
3.3.2
SEWAGE PUMPING STATION NO. 2
Sewage Pumping Station No. 2 was constructed at the Water Pollution Control Plant site in
1978 to service the southeast area of Meaford. The station is a wet well/dry well facility
equipped with two variable speed 50 hp pumps (Fairbanks Morse model 5414). The pumps are
rated at 148 L/s at a TDH of 18.8 m. The wet well has a storage capacity of approximately 22
m³.
Stand-by power is provided by a Harper Detroit 6 cylinder diesel unit with a Brown Boveri
generator rated at 150 kVA at 1800 rpm for a 3 phase/60 Hz/144 Amp/347 V/600 V supply. The
diesel generator is capable of running one of the sewage pumps as well as one of the plant
process aerators, the digester aerator and both clarifier mechanisms for the Water Pollution
Control Plant.
Flow monitoring at the station is done using a Fisher and Porter magnetic flow meter and a
seven day circular chart recorder.
Overflow from SPS No. 2 is directed to the maintenance hole at the shore of Georgian Bay at
the end of Aiken Street. Overflow will only occur following the surcharging of the sewer system
and requires manual operation of a valve located on a 450 mm diameter cross line to the
existing 600 mm plant outfall line.
3.3.3
Sewage Pumping Station No. 3 was constructed in 1995 (Ministry of the Environment Certificate
of Approval No 3-1592-94-956). It is located on the east side of Sykes Street directly north of
Pete’s Creek, approximately 150 m southeast of Grand View Drive.
The pump station consists of a control building approximately 6.4 m x 5.6 m and a 10.5 m³
capacity wet well, equipped with two submersible sewage pumps (one as standby) each have a
capacity of 72.5 L/s @ 9.5 m TDH.
Standby emergency power is provided by a 25 kW natural gas generator set.
3.3.4
Sewage Pumping Station No. 4 is located at the east end of Boucher Street and services the
Stanley Knight complex and a small number of houses in the area.
The pump station is equipped with two Myers WGL20 pumps, each having a rated capacity of
1.7 L/s with 2 hp motors.
This station is essentially a small lift station which transfers flow into an adjacent gravity sanitary
sewer.
3.3.5
Sewage Pumping Station No. 5 is located at the north end of St. Vincent Street and provides
seasonal service to the harbour.
The pump station is equipped with two Myers WG30 pumps, each having a rated capacity of 5
L/s with a 3 hp motor.
March 2011
Page 4
Update
This station is essentially a small lift station which transfers flow into an adjacent gravity sanitary
sewer.
4.0
ASSESSMENT OF SEWERAGE SYSTEM
4.1
FLOW ANALYSIS
A flow-monitoring programme was not undertaken for this sewer model update. The data and
extraneous flow to domestic flow relationship established in the 2004 flow monitoring
programme of various system drainage areas is assumed to remain constant, except for those
areas in which infrastructure improvements have taken place. Pumping station service areas
and key maintenance hole service areas established in the 2004 study have been used to
define system drainage areas. The sewage flow was broken down into three primary
components as follows:
1)
Domestic Flow
2)
Inflow
3)
Infiltration
Through the flow analysis of data collected over the course of the 3-month flow-monitoring
programme in 2004, approximately 20 % of the total sewage flow was found to be extraneous
during dry weather conditions and approximately 70 % during wet weather conditions. Further
flow analysis of pumping stations and key maintenance hole service areas had shown that the
most significant extraneous flow was generated from the following areas:
1)
Nelson Street at Cook Street sewer shed
2)
Nelson Street at the Fire Station sewer shed
It appeared that approximately 100 % of the dry weather and 90 % of the wet weather
extraneous flows occurred in the SPS No. 1 sewer shed, while the remaining 10 % of the wet
weather extraneous flows occurred in the SPS No. 2 sewer shed.
The methodology and detailed results of the original flow analysis are available in the original
report`
To remain consistent with the assumptions in the 2004 computer model, flows from recent
developments and projected flows from proposed developments were based on 1985 MoE
Design Guidelines, which are consistent with the 2008 Guidelines but also provide specific
values. Similarly, a persons/unit factor of 2.4 has been used.
4.2
FIELD INVESTIGATION
No additional field investigation was undertaken for the purpose of this Study.
4.3
HYDRAULIC ANALYSIS
A computer generated hydraulic model of the sewer collection system has been produced using
a software product known as SewerCAD (version 5.6) as supplied by Haestad Methods of
Waterbury Connecticut. Record Drawings and information provided by the Municipality were
used as the basis for the model.
Three base scenarios have been set up in the model including:
•
Theoretical Domestic Sewage Flow
•
Dry Weather Flow
•
Wet Weather Flow
March 2011
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Update
Both the dry and wet weather conditions include the theoretical domestic sewage flow as well as
the extraneous flows measured during dry and wet weather conditions during the 2004 3-month
flow-monitoring program.
Theoretical domestic flows were compared to measured flows at all of the sewage pump
stations and the sewage treatment plant as well as at the five flow monitoring locations to
determine the extraneous flows for dry and wet weather conditions. Further discussion is
included in Appendix C.
4.3.1
2004 Model
For the 2004 investigation, when comparing theoretical (from the model) and measured (at the
pumping stations and the treatment plant as provided by OWCA) flows, it was found that the
flow meter at SPS No. 2 may have required recalibration. The total flow at the sewage treatment
plant should be approximately equal to the sum of the flows at SPS No. 1 and SPS No. 2. In the
model, these numbers added up, however, the data from the flow meters appeared to vary by
approximately 164 m³/d. When calculating the dry weather infiltration by subtracting the
theoretical flows from the measured OCWA data, the result was a negative value of –163.7
m³/d. This would suggest that the flow meter at SPS No. 2 was incorrect and that the dry
weather infiltration for the SPS No. 2 sewershed was negligible.
A comparison of the dry weather flows at each of the five monitoring locations was made. Peak
flows that differed from the average day hydrograph were compared to days of known
precipitation to find a correlation. Storm hydrographs were derived from the rainfall data that
was collected during the 3-month flow-monitoring period from the rain gauge that was installed
temporarily on the roof of Town Hall.
Two storm events that occurred during the monitoring period were analysed. The first storm
occurred between May 1, 2004 and May 2, 2004 and lasted approximately 18 hours. This storm
event, when compared to historical rainfall data for Owen Sound, represented approximately
60% of a 2-year storm for any 12-hour period within the storm event. It can be concluded that
this storm represents an annual event.
The second storm occurred between May 23, 2004 and May 24, 2004 and lasted approximately
16 hours. This storm event, when compared to historical data for Owen Sound, exceeded a
two-year rainfall event for a 30-minute storm duration. The storm also exceeded a ten-year
event for 1 hour, 2 hour and 6 hour storm durations and exceeded a 100-year storm for 12 hour
and 24 hour durations.
The effects of the rainfall events on the sewage flow are further discussed in Appendix C.
4.3.2
2010 Model
All new flow data from new service connections in the newly serviced areas have been
calculated based on an originally adopted occupancy factor of 2.4, average flow of 450 L
/cap/day per resident and standard allowance of 402.5 L /cap/day under wet weather conditions
for inflow & infiltration.
When comparing theoretical (from the updated model) and recently measured flows (as
provided by OCWA) at the pumping stations, it was found that theoretical flows at SPS No. 1
are considerably less than its measured flows. Therefore, in the 2010 model, all flows at the
source in sewer shed No. 1 were recalibrated in order to bridge the gap between theoretical and
measured flows for SPS No. 1.
OCWA rainfall data from 2006 to 2009 has been reviewed. No significant change in rainfall /
storm patterns is found as compared to the previous studies.
March 2011
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Update
4.3.3
2030 Model
Similar methodology has been adopted to update the original 2023 sewer collection system
model. However, as the 2004 model was updated to the 2010 model, the 2023 model was
updated to the 2030 model.
When comparing theoretical (from the updated 2023 model i.e. 2030 model) and recently
measured flows (as provided by OCWA) at the pumping stations, it was found that theoretical
flows at SPS No. 1 are less than its measured flows, but theoretical flows at SPS No. 2 are
much higher than its currently measured flows. The higher flow at SPS No. 2 is obviously due to
the future flows from future developments to the south of the existing municipal sewer collection
system between Meaford’s Corporation Limit at the south side and 12/13 Side Road (Refer to
Drawing 109119-Fig. 2). Therefore, no recalibration or correction is made in the 2030 model as
the flows at the SPSs are anticipated to increase with development.
It is recommended that future model updates include a review of rainfall data and corresponding
recorded sanitary flow data to identify any change in their relationship. If a change is noted, the
base extraneous flow model input data should be adjusted accordingly. This is especially
relevant in areas where the Municipality has undertaken extraneous flow mitigation.
Note: The calibrated and updated hydraulic SewerCAD model can be used to identify sewers
that have the potential to surcharge. The results of the hydraulic analysis are presented in
Appendix C. Using 80% of the pipe capacity as the allowable flow in the system there are no
components in the existing system that appear to be hydraulically overloaded under the current
operating conditions.
5.0
REHABILITATION ALTERNATIVES
Sanitary sewers, service connections and maintenance holes that have been identified as
infiltrating or as being structurally deficient do not necessarily have to be replaced to correct the
problem. Several best practice management systems of pipeline and maintenance hole
rehabilitation have been developed as alternatives to excavation and replacement. These
rehabilitative systems can be less costly than excavation and replacement and often take much
less time to complete. In addition, since most rehabilitative systems require little or no
excavation, this results in far less disruption than excavation and replacement.
6.0
APPROVALS
6.1
ENVIRONMENTAL ASSESSMENT
The Environmental Assessment Act applies to all sewage works. Repairs to, and rehabilitation
of existing sewers are classified as Schedule ‘A’ in the Class Environmental Assessment
process. Schedule ‘A’ works are exempt from the EA process and may proceed at the Town’s
convenience.
6.2
MOE CERTIFICATE OF APPROVAL
A Ministry of the Environment Certificate of Approval is required for all new sewage works and
must be obtained prior to commencing work. Currently, an MOE Certificate of Approval is not
required for the rehabilitation of sewers and maintenance holes unless there is a change in the
hydraulic capacity.
7.0
PROPOSED FUTURE DEVELOPMENT
Consultation with and direction from The Municipality of Meaford Planning Department was
used to develop long-term future growth projections for the Municipality. This is based on an
allotment for development in areas where there is potential for future growth based on zoning
March 2011
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Update
and planned servicing. The projected development potential is based on 10 equivalent
residential units per hectare, per the Municipality. An allowance was also made for the following
areas:
•
Infill in Special Policy Area 3
•
A hotel/convention centre; culinary school, wellness centre/spa; sports complex located on
the 3rd line, south of Highway 26 (Lots 9 & 10 Concession 2). Between 760 and 845
residential units are proposed for this area. The proposal is at the pre-consultation stage.
The Municipality advised that they would expect the sewer main extension would occur
along Hwy 26.
Non-residential growth potential is included in the following areas:
•
The highway commercial land on the east of St. Vincent and north of Hwy 26 (Valumart and
vacant adj. lands). Demands in this area are based on 25% non-residential coverage, per
the Development Charges Background Study dated July 2010 prepared by Hemson
Consulting Ltd. Sewage flows in this area are based on the area, per MOE Design
Guidelines
•
Special Policy Area 4. Sewage flows in this area are based on the area, per MOE Design
Guidelines
The locations of the projected developments are shown on the map found overleaf.
Assumptions were also made regarding where developments would be connected to the
existing distribution system. Full build-out details should be added to the model as they become
available.
The SewerCAD model that has been constructed as part of this study will be a useful tool for the
Municipality of Meaford in planning future development and infilling and tracking ongoing
maintenance and inspection work.
The 2005 Official Plan anticipates that the population of the Municipality of Meaford will grow
between 2,000 and 4,000 over the next 20 years. It is also projects that many of the new
residents will be retirees , however, Meaford is also poised to attract growth from the expanding
recreational / service industry in the wider areas.
The Official Plan identifies an area to the south of the existing developed area (referred to as
Pressure Zone 2C in the Water Supply and Distribution Computer Modeling and Analysis report
prepared by the Ainley Group in the year 2004) as the primary location for future urban growth.
This area is shown in Figure of that report. To be conservative in terms of computer modelling,
we have assumed the maximum projected growth (4,000 persons).
Though not specifically noted in the Town’s draft Official Plan or Zoning By-law, Town staff
wished to include a trunk sewer along Millar Street from Owen Street heading West to the Grey
Road 22 (Seventh Line) to service the development that would occur in the north east quadrant
of Grey Road 12 and Grey Road 22 (Seventh Line) (referred to as Pressure Zone 2A in the
Water Supply and Distribution Computer Modeling and Analysis report prepared by the Ainley
Group in 2004). This area is shown in Figure 3. Because growth projections are not available
for these areas, the projected population density in the south area was also used here. A
population growth of 1,430 was assumed for the 20-year (ultimate) condition.
As per the 2004 model, the design flows for the future sewer capacity are based on the water
average day flow of 450 L/cap/day. The future sewer lines were designed to handle peak
domestic flow plus peak infiltration and inflow. The peak infiltration and inflow was based on a
March 2011
Page 8
Produced by the Municipality of Meaford (KS) Source: MNR
Date: October 26, 2010
Update
per capita allowance of 402.5 L/cap/d for extraneous flow as per the 1985 MOE Design
Guidelines.
In order to determine the depths of the future sewer pipes, Ontario Base Maps (OBM) were
used to identify the contour elevations in the areas of proposed development.
Due to the dramatic variations in elevation in the southern part of Meaford the area cannot be
serviced entirely by gravity sewers. A pumping station, to be named as pumping station no. 6,
will be required to lift the majority of the flows from the southern development area.
8.0
CONCLUSIONS AND RECOMMENDATIONS
8.1
SEWER MAINTENANCE PROGRAMME
Since the report on the Sanitary Sewer Needs Study Ontario Ministry of The Environment
Lifelines Project No. 24-0034-01 was issued in January 1990, many of the maintenance
problems identified in that report have been addressed and corrected.
The Town’s Works Department currently undertakes periodic flushing of known areas of
sediment deposition and removes roots as problems arise. Following the recommendation from
the 2004 report, the Works Department considered a maintenance program that includes the
following:
1)
Flushing of the entire sanitary sewer system on an annual basis,
2)
Inspecting all maintenance holes on an annual basis in conjunction with the flushing
programme,
3)
Annual CCTV inspection of approximately 10 % of the sanitary sewer system, such that
every sewer is inspected every 10 years, and
4)
CCTV inspections of new sewers at the developer’s expense to ensure proper
construction prior to assumption by the Municipality.
Priority has been given to immediate correction of maintenance problems identified during these
inspections.
8.2
PRIORITIZATION OF REHABILITATION
The Municipality has embarked on a multi-year programme of replacing the identified aging
infrastructure, as budget constraints allow. Removal of inflow sources continues to be a high
priority item, which will significantly reduce the peaking factors and maximum day flows for
many drainage areas. It is recommended that roof drains from downtown buildings which are
connected to the sanitary sewer line shall be disconnected when the local sanitary sewers are
reconstructed therein.
8.3
JUSTIFICATION
The justification and benefit for the majority of the rehabilitation work is straightforward. The
following issues are discussed further to reinforce their importance:
8.4
CATCH BASINS
Most catchasins previously identified as being connected to the sanitary sewers have been
disconnected. Some catch basins may still be connected to the sanitary sewer system and may
account for a substantial amount of inflow from rainfall events and runoff from spring snow melt
to enter the sanitary sewer system. This volume of extraneous flow must then be treated at the
sewage treatment plant when it should be directed into the storm sewer system. It is
March 2011
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Update
recommended that the Operations staff continue to be aware of this and to identify any
remaining connected catchbasins.
8.5
STORM SEWER CONNECTIONS
According to municipal records, there are two remaining storm sewer connection points that
allow storm water runoff to enter the sanitary sewer system directly. Catch basins on Edwin
Street near the Henry Street intersection have since been connected to a new storm sewer. The
roof drain leaders from the commercial properties fronting on Sykes Street between Nelson
Street and Trowbridge Street are still connected and continue to contribute a significant volume
of storm water runoff to the overall flows in the sanitary sewer system. The smoke testing
undertaken in earlier years found several other roof drains and eves troughs that were directly
connected to the sanitary sewer system. It is our understanding that these have been redirected
from the sanitary sewers.
8.6
MAINTENANCE HOLES
During video inspections undertaken in earlier years, a buried maintenance hole was discovered
on Albery Court between MH 33500 and MH 33600 approximately 36.8 m from MH 33500. This
maintenance hole was not identified in the 2004 Report.
This maintenance hole is connecting Georgian Court Condominium’s new sewer line to the
existing sewer line on Albery Court and it has been labelled as MH 33550 in the updated model.
8.7
FLOW MONITORING
Flow monitoring is a proven tool that can be used to determine whether or not flows at a specific
sewer shed are similar to the theoretical flows that are expected at that location. The Town now
has the necessary Flo-totes and computer software to collect sewer flow data and can do so to
study areas that are suspected of having infiltration or inflow problems. Short studies can be
undertaken at relatively low cost to determine whether or not sections of sewer require
rehabilitation or replacement.
8.8
SEWAGE TREATMENT PLANT UPGRADES
The correction of the identified deficiencies in the Town’s sewage collection system will
temporarily recover some capacity at the sewage treatment plant and allow for continued growth
of the Town. However, with the constant growth that is occurring in Meaford this capacity will be
used up quickly.
The existing sewage treatment plant in Meaford is a high-rate activated sludge plant, with a
rated capacity for an average daily flow of 3909 m3/day. This plant has been last upgraded in
2005- 2006.
Since then, these upgrades improved effluent quality. However, it is important to maintain and
upgrade the collection system in order and continuously limit the extraneous flows collected by
the system such that the sewage treatment plant operates efficiently and operating costs and
possible future capital cost upgrades are kept to a minimum.
8.9
SEWER SYSTEM (AS MODELLED IN 2004)
The sanitary sewer collection system as modeled in the year 2004 had the necessary hydraulic
capacity for the population of Meaford (former Township of Meaford). However, sections of
sewer pipe needed to be repaired or replaced due to their physical condition as a result of age.
These pipes have been identified in previous studies (by others) and have not been reiterated in
the 2004 model.
March 2011
Page 10
Update
8.10
EXISTING SEWER SYSTEM (2010)
The existing sanitary sewer collection system, with recent sewer additions and upgrades,
appears to have sufficient hydraulic capacity for the existing population of the Municipality.
However, a few sections of sewer pipe may still need to be repaired or replaced due to their
physical condition as a result of age. The sewer line additions and upgrades carried out
between 2004 and 2010 include:
•
•
Sewer collection system additions for approved developments as per 2005 Official Plan:
o
Gates of Kent sewer system (82 new connections)
o
Golfview Sewer System (28 new connections)
o
Pinehurst Sewer System (27 new connections)
Sewer Collection system upgrades as in accordance with other approved plans, for the
following areas:
o
Coleman Street (25 new connections)
o
Birchwood village (1 new connection)
o
Union Street and Grace Avenue intersection (5 remaining out of total 11 connections)
o
Brookside Phase 2 (18 new connections)
o
Ridge Creek Drive (1 remaining out of total 14 connections)
o
Golf Course Villas (13 remaining out of total 20 connections)
o
St. Andrews (16 remaining out of total 34 connections)
o
Memorial Park (a new sewer collection network with 9 nos. manholes, to connect trailer
park and campground)
o
Georgian Court Condominium (12 new connections)
o
Susan Street and Stewart Street intersection (upgrades only, no new connection)
o
Sykes Street and Albert Street intersection (upgrades only, no new connection)
o
Sykes Street/Hwy 26 sewer line addition (upgrades only, no new connection)
o
Edwin Street and Henry Street intersection (upgrades only, no new connection)
o
Maple Meadow Homes (31 new connections)
o
Boucher Street and St. Vincent Street intersection (upgrades only, no new connection)
o
Siljohn Investment (upgrades only, no new connection)
Modelling input of the above sewer collection system additions and upgrades are presented in
the Appendix B2.
8.11
ULTIMATE SEWER SYSTEM (2030)
Several sanitary sewer collection system improvements were identified during updating the
computer model to accommodate the projected population growth over the next 20 years.
These improvements include:
•
Addressing the locations of known inflow into the sanitary sewer collection system
o
These areas are described above and in detail in Appendix D.
March 2011
Page 11
Update
•
Clay sewer pipe on St. Vincent Street.
o
•
•
The grade is negative in the 250 mm sewer pipe on St Vincent Street between Bridge
Street and Boucher Street (approximately 132.5 m). It is recommended that this be
monitored on a regular basis for potential maintenance problems.
Old Sewage Pumping Station No. 1
o
•
Flooding of the pipe downstream of the siphon under the Big Head River and before the
existing Sewage Pumping Station occurs during peak storm flows. The elimination of the
inflow sources should solve this issue, however, further investigation and modeling of
the piping around the old sewage pumping station and the siphon may be required.
Development Area 2C - Future pumping station and trunk sewers to the south
o
Install a new pumping station (to be designated as Sewage Pumping Station #6) on
Coleman Street South of the existing Meaford Corporate Limit. The pumps are to have a
capacity of approximately 35 L/s at a minimum TDH of 5m.
o
Install a 100 mm forcemain (approximately 215 m) between the new sewage pumping
station and a new maintenance hole just south of the end of McKibbon Drive.
o
Install a 200 mm diameter trunk sewer (approximately 668 m) on St. Vincent Street from
the 12/13 Side Road to the existing Meaford Corporate Limit. Connect this sewer to the
existing maintenance hole 20590 with a 300 mm diameter trunk sewer (approximately
14m) at the grades and with maintenance holes as shown on the Profile 1.
o
Install a 200 mm diameter trunk sewer (approximately 575 m) on Coleman Street from
the new pumping station to the 12/13 Side Road at the grades and with maintenance
holes as shown on the Profile 2.
o
Install a 300 mm diameter trunk sewer (approximately 95 m) between the new
maintenance hole just south of the end of McKibbon Drive heading east to St Vincent
Street as shown on Profile 3.
o
Install a 200 mm diameter trunk sewer (approximately 570 m) on Union Street from the
12/13 Side Road north connected to a 250 mm (approximately 210 m) which then
connects in to a 300 mm diameter trunk sewer (approximately 205 m) west from Union
Street to the new pumping station on Coleman Street at the grades and with
maintenance holes as shown on the Profile 3.
o
Install a 200 mm diameter trunk sewer (approximately 686 m) on Centre Street from the
12/13 Side Road north to the existing Meaford Corporate Limit at the grades and with
maintenance holes as shown on the Profile 4.
o
Install a 200 mm diameter trunk sewer (approximately 222 m) connected to a 250 mm
diameter trunk sewer (approximately 111 m) east from Centre Street to Union Street at
the grades and with maintenance holes as shown on the Profile 4.
o
Install a 250 mm diameter trunk sewer (approximately 94 m) on Union Street at the
grades and with maintenance holes as shown on the Profile 4.
o
Install 200 mm diameter trunk sewer (approximately 1131 m) along the Georgian Trail
from Hwy. 26 to connect at Montgomery Street.
Development Area 2D - Future trunk sewers to the west:
o
Install 200 m diameter trunk sewer (approximately 1818 m) on Miller Street from the
Seventh Line to connect at Owen Street.
March 2011
Page 12
Update
It is to be noted that these system expansions are based on growth as outlined in the
Municipality of Meaford Official Plan and the Municipality of Meaford Development Charges
Study Background Report. These expansions are preliminary trunk sewer designs only and do
not include detailed pipe layout to subdivisions.
9.0
CAPITAL COST ESTIMATE (20 YEAR PHASING)
Where possible, the sewer upgrades/extension works have been synchronized with the
waterworks upgrades/extensions.
9.1
IMMEDIATE UPGRADES
Many of the original downtown buildings have the roof drains draining to the sanitary sewer. It
has been concluded in earlier studies and during this study that disconnection of these roof
drains should be considered when the local sanitary sewers are reconstructed and/or when
major renovations to the individual buildings are undertaken.
QUANTITY UNIT UNIT PRICE
ITEM
Disconnect various eavestrough downspouts from sanitary sewer
200 mm dia. trunk sewer on St. Vincent Street from the 12/13 Side
Road to existing maintenance hole 20590
9.2
TOTAL
8
ea
$500
$4,000
668
m
$300
$200,400
Sub-Total
$204,400
Engineering & Contingencies @ 20%
$40,900
TOTAL
$245,300
SAY
$245,000
2015 UPGRADES
ITEM
200 mm dia. trunk sewer along the Georgian Trail from Hwy. 26 to
1131
ea
$300
Montgomery Street.
Sub-Total
March 2011
TOTAL
$339,300
$339,300
$67,680
TOTAL
$407,160
SAY
$407,000
Page 13
Update
9.3
2020 UPGRADES
ITEM
New pumping station on Coleman Street South of the former Meaford
Corporate Limit. Pumps duty point of approximately 35 L/s at 5m
1
ea
$1,800,000
TDH
.
100 mm forcemain between the new sewage pumping station and a
new maintenance hole just south of the end of MiKibbon Drive.
215
m
$295
200 mm diameter trunk sewer on Coleman Street from the new
pumping station to the 12/13 Side Road
300 mm diameter trunk sewer between the new MH just south of the
end of McKibbon Drive east to St Vincent Street
200 mm diameter trunk sewer on Centre Street from the 12/13 Side
Road north to the former Meaford Corporate Limit
250mm diameter trunk sewer from Union Street to Coleman Street
200 mm diameter trunk sewer (approximately 222 m) connected to a
250 mm diameter trunk sewer (approximately 111 m) east from
Centre Street to Union Street
250 mm diameter trunk sewer on Union Street
200mm diameter trunk sewer on Union Street from 12/13 sideroad to
proposed 250mm diameter trunk sewer
9.4
TOTAL
$1,800,000
$63,400
575
m
$443
$254,700
95
m
$494
$46,900
686
m
$470
$322,400
415
m
$480
$199,200
333
m
$482
$160,500
94
m
$483
$45,400
570
m
$470
$267,900
Sub-Total
$3,160,400
$632,080
TOTAL
$3,792,480
SAY
$3,792,000
2025 UPGRADES
No upgrades or extensions are anticipated for 2025.
9.5
2030 UPGRADES
ITEM
200 m dia. trunk sewer on Miller Street from the Seventh Line to
1818
ea
$300
connect at Owen Street.
Sub-Total
TOTAL
$545,400
$545,400
$109,080
TOTAL
$654,480
SAY
$655,000
S:\109119\109119\Reports\FINAL June 10 sanitary sewer model report final-2013-01-09-nes-MWA-NES REVISIONS.doc
March 2011
Page 14
Update
APPENDIX A: SEWER USE BY-LAW
Update
APPENDIX B1: SANITARY SEWER ELEMENTS
Update
APPENDIX B2: UPGRADES & ADDITIONAL DEVELOPMENT
BETWEEN 2004 TO 2010
APPENDIX - B2
MUNICIPALITY OF MEAFORD
Computer Modeling and Analysis - Upgrades & Additional Development between 2004 to 2010
Drawing #
Description
Length (m)
Pipe Size (mm)
Upstream MH
Upstream
Ground Level
Upstream MH
INV. Level
Downstream MH
Downstream
Ground Level
Downstream MH
INV. Level
Grade (%)
1
106096-RC1
Edwin Street Part 1
22.50
200
10719
500
S.E.187.55
10718
189.29
W. 187.42
0.56
2
106096-RC1
Edwin Street Part 1
96.10
200
10718
189.29
S.E. 187.46
10717
189.63
Serial #
Remarks
Edwin St./Henry St.
W. 186.93
0.56
3
4
106096-RC2
106096-RC7
Edwin Street Part 2
Across Edwin Street
26.30
5.20
200
150
10717
Stub 1
189.63
189.50
E. 186.92
N. 187.51
10710
10710
189.65
189.65
W. 186.91
S. 186.81
0.56
13.46
5
106096-RC7
Henry Street
15.50
200
10710
189.65
N. 186.68
10825
189.22
S.186.49
1.21
6
106096-RC7/RC6
Henry Street
110.80
200
10825
189.22
N. 186.47
10830
187.31
S.185.37
0.99
7
106096-RC6/RC5
Henry Street
66.60
200
10830
187.31
N.185.35
10835
186.79
S.E.184.72
0.95
8
106096-RC5
Henry Street
76.20
200
10835
186.79
N.W.184.64
10840
186.05
S.183.30
0.50
183-2737-111
183-2737-103
183-2737-108
183-2737-103
183-2737-108
183-2737-103
183-2737-108
183-2737-103
Union Street
Main Road
Third Lane
Main Road
Second Lane
Main Road
First Lane
Main Road
98.70
96.70
80.40
66.20
80.40
66.10
80.40
87.50
200
200
200
200
200
200
200
200
17610
17620
17630
17640
17650
17660
17670
17680
213.25
214.67
213.99
214.52
213.83
214.23
213.55
214.70
N. 208.97
E. 209.53
S. 211.14
E. 209.89
S. 210.98
E. 210.25
S. 210.75
E. 211.89
17600
17610
17620
17620
17640
17640
17660
17660
212.28
213.25
214.67
214.67
214.52
214.52
214.23
214.23
S. 208.48
W. 209.05
N. 219.34
W. 209.56
N. 210.18
W. 209.92
N. 210.33
W. 210.28
0.50
0.50
1.00
0.50
1.00
0.50
0.50
1.80
102022-OP1-RD
107065-SS1-RD
107065-SS1-RD
107065-SS1-RD
107065-SS1-RD
102022-OP1-RD
102022-OP1-RD
102022-OP1-RD
102022-OP1-RD
Memorial Park Main
Gravel Road
Gravel Road
Gravel Road
Gravel Road
Memorial Park Main
Memorial Park Main
Memorial Park Main
Memorial Park Main
51.00
17.00
34.00
24.00
47.00
53.00
60.00
120.00
120.00
200
150
150
200
200
200
200
200
200
20385
20384.7
20384.6
20384.3
20384.1
20384
20383
20382
20381
187.30
190.77
190.79
189.73
188.70
186.75
186.00
185.00
183.85
W. 185.76
W. 188.34
N. 188.12
N. 187.41
N. 186.50
W. 184.84
W. 184.28
W. 183.32
W. 182.21
20384
20384.6
20384.3
20384.1
20384
20383
20382
20381
20380
186.75
190.79
189.73
188.70
186.75
186.00
185.00
183.85
183.52
E. 184.89
E. 188.17
S. 187.46
S. 186.57
S. 184.95
E. 184.31
E. 183.35
E. 182.24
E. 181.61
1.70
1.00
2.00
3.50
3.50
1.00
0.90
0.90
0.50
Across Albery Court
Along Sykes Street
Along Sykes Street
84.00
77.00
19.30
200
200
200
33570
33580
33590
187.98
187.42
186.47
E. 185.60
E. 185.16
S.E. 184.75
33580
33590
33600
187.42
186.47
185.69
W. 185.18
W. 184.77
N.W. 184.65
0.50
0.50
0.50
102178
102178
102178
102178
Maple Lane
Pine Street
Pine Street
Pine Street
29.00
46.00
41.00
82.00
200
200
200
200
20465
20439
20436
20433
500
500
500
500
S. 190.88
N. 189.00
E. 187.50
E. 186.50
20460
20436
20433
20430
500
500
500
500
N. 190.71
S. 187.55
W. 186.55
W. 186.00
0.50
3.15
2.32
0.61
107048-Drg1
107048-Drg1
107048-Drg1
107048-Drg1
107048-Drg1
Iron Wood Drive
Iron Wood Drive
Iron Wood Drive
Iron Wood Drive
Iron Wood Drive
71.00
48.50
66.00
96.00
72.00
200
200
200
200
200
12825
12830
12835
12840.1
12845
205.65
205.08
204.75
204.28
203.79
N. 202.62
N. 202.24
E. 201.99
E. 201.70
E. 201.29
12830
12835
12840.1
12845
12860
205.08
204.75
204.28
203.79
203.51
S. 202.26
S. 202.04
W. 201.72
W. 201.31
200.95
0.50
0.40
0.42
0.40
0.50
MH 12860 is the existing manhole
Thompson St./Collingwood
Thompson Street
Thompson Street
Parker St/Thompson St.
78.00
49.00
111.00
72.70
200
200
200
200
12154
11840
11830
11850
186.38
186.25
186.41
187.28
S. 183.84
N. 184.64
N. 184.29
E. 185.32
12152
11830
11820
11830
186.32
186.41
186.08
186.41
N. 183.45
S. 184.33
S. 183.81
W. 184.33
1.00
0.60
0.40
1.40
MH 10830 is located across Margaret St.
Gates of Kent Area
1
2
3
4
5
6
7
8
Memorial Park
1
2a
2b
2c
2d
3
4
5
6
Pinehurst Estate
1
2
3
106118-Drg.3
106118-Drg.3
106118-Drg.3
Maple Meadow Homes
1
2
3
4
Golf View Estates
1
2
3
4
5
Thompson St. / Nelson St.
1
2
3
4
102178-RC2
102178-RC3
102178-RC4
102178-RC6
Georgian Court Condominiums
1
2
3
104211
104211
104211
Across Albery Court
Across Albery Court
Across Albery Court
48.50
54.00
36.20
200
200
200
33520
33530
33540
500
500
500
S. 186.43
E. 186.18
S. 185.88
33530
33540
33550
500
500
500
N. 186.23
W. 185.96
N. 185.70
0.40
0.40
0.50
Parallel to Ridge Road
Parallel to Ridge Road
Parallel to Sykes Street
Ridge Road
Across Ridge Road
16.50
47.20
65.70
52.40
20.20
200
200
200
200
200
33000
Stub 30
33100
36500
36400
190.78
190.93
191.29
194.81
194.62
189.42
189.31
189.06
S.192.39
W.192.08
33100
33100
33200
36400
36300
191.29
191.29
189.57
194.62
194.59
N189.14
S189.07
W.186.95
N.192.13
E. 191.95
1.00
1.00
3.26
0.50
0.50
MH 33550 is placed between existing MH
33500 and 33600
Albery Court/Ridge Road
1
2
3
4
5
102139-SS1-RD
102139-SS1-RD
102139-SS1-RD
190185-S2
190185-S2
towards Albery Court through Vacant Land
Sykes St./Albert St.
1
1
101153-SW2RD
101153-SW1RD
Albert Street
Sykes Street
10.00
94.50
200
450
11780
11620
180.49
180.45
E. 179.30
S. 178.00
11620
11610
180.45
180.80
W. 178.60
N. 177.75
6.00
0.30
3
4
5
6
7
101153-SW2RD
101153-SW3RD
101153-SW4RD
101153-SW4RD
101153-SW4RD
Sykes Street
Sykes Street
Sykes Street
Sykes Street
Sykes Street
69.50
63.60
63.50
55.50
12.50
375
375
375
375
375
11631
11630
11650
11660
11670
181.16
181.53
181.76
181.55
181.45
S. 178.36
S. 178.65
S. 178.95
S. 179.24
S. 179.30
11620
11631
11640
11650
11660
180.49
181.16
181.53
181.76
181.55
N. 178.14
N. 178.40
N. 178.75
N. 179.03
N. 179.26
0.30
0.30
0.40
0.55
0.60
101172
101172
101172
101172
101172
101172
101172
Ridge Road
St. Andrew's Drive
St. Andrew's Drive
St. Andrew's Drive
St. Andrew's Drive
St. Andrew's Drive
St. Andrew's Drive
Victoria Street
82.30
40.00
35.00
78.00
85.00
85.00
85.00
41.00
200
200
200
200
200
200
200
200
12914
12913
12912
12911
12910.1
12909
12908
12907
197.60
194.00
190.19
189.95
190.29
189.89
188.65
188.05
N.W. 194.50
E. 191.68
E. 189.90
S.E. 188.49
E. 187.96
E. 187.20
E. 186.24
N. 185.34
12913
12912
12911
12910.1
12909
12908
12907
12901
194.00
190.19
189.95
190.29
189.89
188.65
188.05
187.71
S.E. 191.68
W. 190.00
W. 188.55
N.W. 188.02
W. 187.24
W. 186.27
W. 185.39
S. 185.13
3.45
3.90
4.00
0.60
0.89
1.10
1.00
0.50
S-1328-Drg.3
S-1328-Drg.3
S-1328-Drg.3
Glen Abbey Court
Glen Abbey Court
Glen Abbey Court
25.00
83.00
51.00
200
200
200
12917
12916
12915
200.81
200.45
198.60
N.W.197.85
N. 197.32
N. 195.33
12916
12915
12914
200.45
198.60
197.60
E. 197.37
S. 195.35
S.W. 194.60
1.00
2.34
1.29
Susan Street
Susan Street
Stewart Street
Susan Street
Susan Street
Stewart Street
100.00
88.00
120.00
75.00
69.00
106.50
200
200
200
200
200
200
32850
32810
36501
32770
32730
36550
194.00
191.48
190.18
189.78
189.70
190.35
N.E. 190.80
E. 188.14
S. 187.95
E. 187.34
E. 186.96
N 187.77
32810
32770
32770
32730
32690
36600
191.48
189.78
189.78
189.70
189.20
190.38
S.W. 188.19
W. 187.39
N. 187.41
W. 187.00
W. 185.82
S. 187.18
2.60
0.85
0.45
0.45
0.16
0.55
Sykes Street
Sykes Street
Sykes Street
Sykes Street
Sykes Street
Sykes Street
Sykes Street
Sykes Street
Sykes Street
Sykes Street
26.50
37.20
79.20
116.20
104.70
80.00
97.50
100.00
100.00
74.30
200
200
200
200
200
200
200
200
200
200
10760
10770
10780
10781
10783
10785
20551
20552
20553
20554
205.20
206.08
208.00
210.35
212.15
213.25
215.24
216.40
217.09
217.10
W. 202.75
W. 203.60
W. 205.39
W. 207.70
W. 209.33
W. 210.18
W. 210.29
W. 211.29
W. 212.29
W. 213.03
10750
10760
10770
10780
10781
10783
20550
20551
20552
20553
204.57
205.20
206.08
208.00
210.35
212.15
213.97
215.24
216.40
217.09
E. 202.70
E. 202.80
E. 203.65
E. 205.44
E. 207.75
E. 209.38
E. 209.32
E. 210.30
E. 211.30
E. 212.30
2.00
2.20
2.20
1.95
1.50
1.00
1.00
1.00
1.00
1.00
Boucher Street
Boucher Street
66.50
64.00
375
375
11030
11045
181.40
182.51
W. 179.22
E. 179.01
11045
11150
182.51
182.41
E. 179.14
W. 178.90
0.12
0.19
Gordon Crescent South
27.00
85.00
40.00
70.00
55.00
200
200
200
200
200
12806
12805
12804
12803
12802
212.48
212.40
211.19
207.49
211.08
W. 209.60
N. W. 209.28
N.W. 208.68
E. 208.40
E. 208.09
12805
12804
12803
12802
12800
212.40
211.19
207.49
211.08
211.90
E. 209.33
S.E. 208.73
S.E. 208.50
W. 208.11
207.90
1.00
0.65
0.45
0.42
0.42
Existing MH 12800 is on Coleman Street
Sykes Street South
Sykes Street South
58.00
13.00
200
300
Stub 3
11295
500
181.25
179.85
179.54
11295
11290
181.25
181.48
179.62
177.67
0.40
14.39
Siljohn is at the intersection of Boucher St.
and Sykes St.
St. Andrew's Drive
1
101172
2
3
4
5
6
7
8
MH 11610 is at the intersection of Sykes St.
and Bayfield St.
MH 11640 is at the intersection of Sykes St.
and William St.
MH 11660 is at the intersection of Sykes and
Cook St.
MH 12913 is at the intersection of William
St. and Victoria St.
Golf Course Villas
1
2
3
Susan Street / Stewart Street
1
2
3
4
5
6
105151-SW1RD
105151-SW1RD
105151-SW2RD
105151-SW1RD
105151-SW1RD
105151-SW2RD
MH 32770 is at the intersection of Sykes St
and Ivan St.
Sykes Street (Hwy 26)
1
2
3
4
5
6
7
8
9
10
102114-RC1-RD
102114-RC1-RD
102114-RC1-RD
102114-RC2-RD
102114-RC3-RD
102114-RC4-RD
102114-RC5-RD
102114-RC6-RD
102114-RC7-RD
102114-RC8-RD
MH 20550 is the existing manhole at the
intersection of Sykes St. and St. Vincent St.
Boucher Street / St. Vincent Street
1
2
106174-RC2-RD
106174-RC1-RD
Coleman Subdivision
1
2
3
4
5
S-1387-DWG1
S-1387-DWG1
S-1387-DWG1
S-1387-DWG1
S-1387-DWG1
Siljon Investments Inc.
1
2
303005-02
303005-02
Update
APPENDIX C: FLOW ANALYSIS
Report On
Sanitary Sewer Collection System Model
Appendix ‘C’ Flow Analysis
The following sections are reproduced from the original 2004 investigation.
2004 INVESTIGATION
Introduction
A flow analysis of various system drainage areas was undertaken to determine sections
with significant extraneous flows. Pumping station sewersheds and key maintenance
hole sewersheds within the Town were used to defined system drainage areas. A
method was established by which the sewage flow could be broken down into three
primary components as follows:
1)
2)
3)
Domestic Flow
Inflow
Infiltration
It is understood that some inflow/infiltration is inherent in any sewage collection system.
A reasonable allowable quantity of inflow/infiltration had to be determined, while
ensuring that the calculated amount does not hide the magnitude of these flow
components.
Sewage Treatment Plant and Pumping Stations
The sewage flow data from the sewage treatment plant (2000-2003) and the five sewage
pumping stations (2003) was provided by the operator and the calculated theoretical
base flow were used to determine the wet weather and dry weather extraneous flows.
Large Contributors
The water records for the sixteen largest water users were obtained from the Meaford
Public Utilities Division. This water consumption was subtracted from the total Town
consumption for the purpose of determining the average domestic consumption. The
sewage flow for each of the sixteen “large users” was assumed to be 90% of the water
consumption from September to May and 70 % of the water consumption from June to
August. This Sewage flow was then input into the model at the specific nodal location of
each large user.
Domestic Flow
Domestic sewage flow was calculated on a per lot basis. Using the average water
demands with the sixteen large users and other known losses due to fire, flushing leaks
etc. excluded, 90% of the water consumption for September to May and 70% of the
water consumption for June to August was assumed to be equal to the total domestic
sewage flow. The total sewage flow was divided by the total number of lots that,
Appendix ‘C’
Flow Analysis
Page 1
according to Town records, have a water service connection. Each lot was then
assigned to a sewage sewershed and the total number of contributing lots for each
sewershed was assigned to a node in the model.
Allowable Inflow/Infiltration
Allowable inflow and infiltration was determined by using the Ontario Provincial Standard
Specifications calculation of extraneous flow allowances for new sewers recommended
in the MOE Guidelines for the Design of Sanitary Sewage Works. “Division 410 of the
Ontario Provincial Standard Specifications lists an allowable extraneous flow/leakage
(infiltration/exfiltration) of 0.075 Litres/millimetre diameter per 100 metres of sewer per
hour”. The Specification also states that based on a typical plan of subdivision, the
value for extraneous flow/leakage can be determined using either 22 L/cap*d or 0.01
L/ha*s.
A value of 0.022 m³/cap*day (22 L/cap*day) was used to calculate the allowable
inflow/infiltration. The total allowable extraneous flow based on the approximate
population of Meaford of 4,800 is approximately 105.6 m³/d. The actual dry weather
infiltration is approximately three times as much, 310.7 m³/d.
Infiltration
The Town of Meaford has a limited number of large water users. It can be assumed that
the large users and the Town’s general population are relatively inactive during the night.
Therefore, it can be assumed that the lowest recorded flow in a month is representative
of the base infiltration. The lowest recorded flow was found to occur typically between
the hours of 1:00 am and 3:00 am.
Dry and wet weather infiltration was determined for the Water Pollution Control Plant
(WPCP) and the five sewage pumping stations by comparing the theoretical domestic
sewage flow with the recorded flows for August (dry) and March (wet). From the
calculations it was determined that approximately 100 % of the dry weather infiltration
and 90 % of the wet weather infiltration occurs in the SPS No. 1 sewershed with the
remaining 10 % of the wet weather infiltration occurring in the SPS. No. 2 sewershed.
Approximately 10 % of wet weather infiltration that occurs in the SPS No. 1 sewershed
can be attributed to the SPS No. 3 sewershed.
The data collected at the six Flo-Tote locations was used to further specify the locations
of the infiltration. The dry weather flow data was inconclusive, however, the wet weather
data was used to narrow down were the majority of the wet weather infiltration is being
generated. Calculations for determining dry and wet weather infiltration for the different
sewersheds is included at the end of this appendix.
A calculated value of infiltration was assigned to each sewer shed on a per meter basis
as outline in Table 1.
Appendix ‘C’
Flow Analysis
Page 2
Table 1 – Infiltration Per Meter of Sanitary Sewer
Sewershed
SPS No. 1
SPS No. 2
SPS No. 3
Nelson Street and Cook Street
Nelson Street at Fire Station
Dry Weather Infiltration
(m³/d/m of sewer)
Wet Weather Infiltration
(m³/d/m of sewer)
0.017
0
0.017
0.017
0.017
0.103
0.044
0.059
0.027
0.907
Inflow
Following the smoke testing of several sections of sanitary sewer in Meaford it was
discovered that several roof drains and eves troughs were connected to the sanitary
sewer system. For the purposes of the computer simulation we have allowed for a per
connection inflow from a 100 m² impermeable area to enter the sanitary sewer for each
connection during a storm event. This is the approximate roof area of a 2,000 ft² house.
The May 1-2, 2004 storm event represents an “annual” rainfall event. This type of event
results in a total of 2.87 m³ of water entering the sanitary sewer at each connection in
the Meaford sanitary sewer collection system. The inflow for the major storm event that
occurred on May 23-24, 2004 will be 18.57 m³ for each connection.
The smoke testing also revealed two areas with several storm catchbasins connected to
the sanitary sewer. These locations are on Cook Street between Nelson Street and
Collingwood Street and on Trowbridge Street between Cook Street and Sykes Street.
As well, several catchbasins on Edwin Street are connected to the sanitary sewer. The
Town is aware of this. These three locations are estimated to contribute a total inflow to
the sanitary sewer system of 157.1 m³, 157.3 m³ and 881.7 m³ respectively during an
annual storm event and 631.3 m³, 631.3 m³ and 3,539 m³ respectively during a major
storm event. Hydrographs are used to input the two storm events into the model with
varying intensities throughout the duration of the events.
It should be noted that inflow would occur at other locations throughout the sewer
system; however, further investigation is required to determine the extent of the inflow
prior to being able to include it in the computer model. For the three areas where more
detailed information is available the inflow was input into the model at a maintenance
hole immediately downstream of the area of known inflow.
Sewage Treatment Plant
A total theoretical daily domestic sewage flow rate was calculated to be 1,317.3 m³/d
and compared to the recorded value for dry weather flow (1,628 m³/d) and wet weather
flow (4,336 m³/d) at the sewage treatment plant. The flows entering the sewage
treatment plant are from two forcemains (SPS No. 1 and SPS No. 2). As such it is
expected that the total flow from SPS No. 1 and SPS No. 2 should equal the total flow
recorded at the sewage treatment plant.
Appendix ‘C’
Flow Analysis
Page 3
The flows in the SewerCAD model, which represents the theoretical flows, add up
correctly. However, the recorded flows at the pump stations and the sewage treatment
plant do not add up. In fact the recorded flows for SPS No.1 and SPS No. 2 are
approximately 164 m³/d less than the recorded flow at the sewage treatment plant for dry
weather flow and 78 m³/d less for wet weather flow. This suggests that there may be a
problem with the flow meters.
Sewage Pumping Stations
The domestic flow rates calculated on a per lot basis, as described above, were applied
to the various sub-drainage areas. The sub-drainage areas are defined as the pump
station service areas. The flow generated by the large users was added to the
calculated domestic flow component. This established an estimated theoretical sewage
flow. By comparing the theoretical sewage flows to the actual recorded sewage flows,
the quantity of extraneous flow can be determined. Recorded dry weather flows were
taken in the month of August while recorded wet weather flows were taken in the month
of March. When compared to the theoretical flows, the dry and wet weather flows will
show approximations of the low and high limits of extraneous flow during the year.
Sewage Pumping Station No. 1 – Bighead River
The Bighead River Sewage Pumping Station services approximately 1,311 lots and 12
large users including one public school, hospital, community centre, retirement home
and several small commercial establishments.
Flow records for the Bighead River Sewage Pumping Station were provided by the
operator. Theoretical and recorded flows are compared in Table 2.
Table 2 – SPS No. 1 Theoretical vs. Recorded Flows
Condition
Dry Weather
Wet Weather
Theoretical Flow
(m³/d)
Recorded Flow
(m³/d)
Extraneous Flow
(m³/d)
1,019.5
1,019.5
1,330
3,704
310.4
2,685.4
The sewershed for SPS No. 1 is large and includes more than 75% of the total sewer
service connections. The extraneous flow during dry weather is relatively low
considering the size of the sewershed and the approximations made in the model,
however it should be noted that almost 100% of the dry weather extraneous flow
appears to occur in the SPS No. 1 sewershed.
Elevated extraneous flows occur under wet weather conditions. This suggests that
increased infiltration occurs with an elevated water table and that inflow may be a
significant contributor to overall sewage flows during wet weather storm events. Of the
total wet weather extraneous flow approximately 90% occurs within the SPS No. 1
sewershed.
Sewage Pumping Station No. 2
Sewage Pumping Station No. 2 services approximately 364 lots and 2 big users
including Georgian Bay Secondary School
Appendix ‘C’
Flow Analysis
Page 4
Flow records for SPS No. 2 were provided by the operator. Theoretical and recorded
flows are compared in Table 3.
Condition
Theoretical
(m³/d)
Dry Weather
Wet Weather
297.7
297.7
Flow Recorded
(m³/d)
Flow Extraneous
(m³/d)
134
554
Flow
- 163.7
256.3
The sewershed for SPS No. 2 includes approximately 20% of the total sewer service
connections. The extraneous flow during dry weather, after comparing theoretical and
recorded flows, result in a negative number. As noted above in the Sewage Treatment
Plant Section, the total recorded flow from SPS No. 1 and SPS No. 2 is 160 m³/d less
than the recorded flow at the sewage treatment plant, approximately the same value as
the negative extraneous flow for dry weather conditions. This further suggests that there
is a problem with the flow meters and that it is at SPS No. 2.
Assuming that the flow meter at SPS No. 2 in fact requires calibration it can be
concluded that negligible dry weather extraneous flow occurs in the SPS No. 2
sewershed.
The extraneous flow under wet weather conditions almost doubles the expected
theoretical flow. Still, this only accounts for approximately 10% of the total wet weather
extraneous flow. This suggests that infiltration is a problem when the water table is high
and that inflow may be occurring during storm events.
Sewage Pumping Station No. 3 services approximately 187 lots and 2 large users
including the water treatment plant.
Flow records for SPS No. 3 were provided by the operator. Theoretical and recorded
flows are compared in Table 4.
Condition
Dry Weather
Wet Weather
Theoretical Flow
(m³/d)
Recorded Flow
(m³/d)
Extraneous Flow
(m³/d)
137.2
137.2
129
437
- 8.2
299.8
The sewershed for SPS No. 3 includes approximately 10% of the total sewer service
connections. The extraneous flow during dry weather after comparing theoretical and
recorded flows result in a negative number. However, this number is relatively low (less
than 9 m³/d) and may be attributed to approximations in the model. It does suggest that
the extraneous flow in the SPS No. 3 sewershed is negligible.
The extraneous flow under wet weather conditions is more than three times the
expected theoretical flow. This suggests that infiltration is a problem when water table
Appendix ‘C’
Flow Analysis
Page 5
are high and that inflow may be occurring during storm events. The wet weather
extraneous flow in the SPS No. 3 sewershed accounts for approximately 10% of the
extraneous flow attributed to the SPS No. 1 sewershed or approximately 9% of the
overall extraneous flow.
Sewage Pumping Station No. 4 services only 1 lot and the former Globe Mills Site.
Because of its low flows and small service area this sewershed was not considered
further in this study.
Sewage Pumping Station No. 5 services only 3 lots and the Meaford harbour, which
includes the Harbour Masters Office and the Canadian Coast Guard. It should be noted
that a sewage pump-out for boats exists at the marina and contributes sewage flow to
the collection system that is not accounted for through domestic flow calculations. This
is a seasonal flow that occurs in the summer months and is relatively small.
Because of its low flows and small service area this sewershed was not considered
further in this study.
Flow Monitoring
Temporary sewage flow monitoring stations were established at several specific
locations where the Town felt that extraneous flows may be originating from. The Ainley
Group provided five flow monitors known as Flo-totes and the Town provided two. Six
Flo-totes were installed with the seventh Flo-tote being used as a spare. The flow
monitoring began on April 2, 2004 and was completed on July 5, 2004, allowing for data
collection during both wet and dry seasons and the Victoria Day Holiday and Canada
Day long weekends. Several significant rainfalls occurred during the monitoring period,
providing evidence of extraneous flows. The Flo-totes were programmed to take
measurements for one minute every five minutes. The Town downloaded the data from
the Flo-totes approximately once a week for the duration of the study. This allowed for
the data to be checked and the Flo-tote to be adjusted, if required.
Estimated average day flows were calculated for the Flo-tote drainage areas based on
the per lot domestic flow rates established from the water consumption records. The
flows generated by the large users were added to estimated average day flows. The
quantity of actual extraneous flow in these areas was determined by comparing the
theoretical and recorded flows.
It was anticipated that the Flo-tote sewersheds could be used to further narrow down the
areas of high extraneous flow. However the data for dry weather conditions was
inconclusive. It was determined that the Nelson Street and Cook Street and the Nelson
Street and Fire Station Flo-totes could be used to further narrow down the source of the
majority of the extraneous flow in the SPS No. 1 sewershed. The other Flo-tote
sewersheds were found to be too specific and thus too susceptible to dramatic extremes
in flow.
Appendix ‘C’
Flow Analysis
Page 6
The velocity, level and flow data were plotted for each Flo-tote site. Rainfall data was
also collected during the study period from a rain gauge that was established on the roof
of Town Hall. The data was then plotted inversely on the same graph as the Flo-tote
data. This will show the correlation between rainfall events and increases in sewage
flows. The graphs for each site are included at the end of this appendix and are
discussed further in the following sections.
Grant Avenue
The sewershed of the Flo-tote on Grant Avenue includes the sewage flow from Memorial
Park and the campground. The theoretical sewage flow was based on a per-lot
domestic flow and does not allow for the flow generated at Memorial Park. Memorial
Park includes 144 campsites. The MOE guidelines for sewage flow from campsites
suggests between 275 and 375 litres per site per day. This results in an expected
sewage flow of between 39.6 and 54 m³/d.
The average sewage flow recorded by the Grant Avenue Flo-tote between April 4, 2004
and July 5, 2004 was only 23.3 m³/d. This is well below even the low end of the MOE
guidelines.
A dry weather base flow was calculated by averaging the record flow between June 16,
2004 and July 4, 2004. This resulted in a dry weather base flow of 15.9 m³/d, which was
input at maintenance hole 20380 in the SewerCAD model.
The graph of the Flo-tote and rainfall data for Grant Avenue site confirms what was
expected for this site. During spring snowmelt and run off the flows are higher,
suggesting that there may be some points of infiltration as the ground water table is high.
This pattern is again evident during the rainfall events that occurred throughout the study
period. The impact of rainfall is seen almost immediately which suggests that there may
be significant inflow.
The flows at this location subside following the spring snowmelt and run off, but then
increase in the summer months as the campgrounds are populated with summer guests.
It appears that this area is subject to dramatic seasonal flows.
Henry Street and Margaret Street Intersection
The graph of the Flo-tote and rainfall data for the Henry Street and Margaret Street site
shows some interesting trends. During spring snowmelt and runoff the flows are higher
than average, suggesting some infiltration may be occurring during periods when the
water table is high. As well this section of sewer connects to Edwin Street where several
catch basins are tied into the sanitary sewer collection system. This is obvious by the
drastic and immediate increase in flows that occurred during the major rainfall event on
the Victoria Day Holiday long weekend.
During the period from approximately May 5th to May 11th some elevated flow and level
readings were recorded, however there was no significant rainfall event during this time.
These elevated flows and levels have been attributed to some debris that collected
around the sensor. This debris was removed and the Flo-tote was replaced on May 11th.
Appendix ‘C’
Flow Analysis
Page 7
On several occasions during the data collection period small amounts of silt were
observed to have collected around the sensor. These may have entered the system
through the catch basins at Edwin Street.
Nelson Street and Cook Street Intersection
The graph of the Flo-tote and rainfall data for the Nelson Street and Cook Street site
shows a very clear diurnal curve. The flow is elevated during the spring snowmelt and
runoff which suggests that there may be significant infiltration when the groundwater
table is elevated. This is further demonstrated by the elevated flows that occur following
rainfall events. The impact of rainfall events is not immediate as at the Henry Street and
Margaret Street Site, rather it is delayed further reinforcing the suspision that infiltration
occurs when the groundwater table is elevated.
Gravel and sediment build up was observed by Town staff each time the sensor was
checked. On one occasion a large brick and some stone debris had collected behind
the sensor. This may be related to a cracked or broken pipe in the system, which would
allow groundwater and sediment into the pipe.
Further analysis of the theoretical flow and the recorded average wet weather flow
indicates that the Nelson Street and Cook Street site sewershed accounts for
approximately 2.5% of the extraneous flow within the SPS No.1 sewershed, almost 59
m³/d.
Nelson Street at the Fire Station
The Nelson Street at the Fire Station site encompasses the largest sewershed of all the
Flo-tote sites and, as such, consistently had the highest flows. Due to the higher
contributing population evidence of the effects of spring snowmelt and runoff are less
obvious. Velocity and level of flow in the pipe is more consistent than the other sites.
Surcharging occurred between May 6th and 11th. This is evident by the sudden drop in
velocity and flow and the sudden increase in level. It was determined that the
surcharging was due to blockage at the inverted siphon at the Big Head River sewage
pumping station caused by a large piece of concrete. Town staff had discovered several
other maintenance holes in the area that had surcharged. They removed the plug at the
siphon on May 25 and no further evidence of surcharging was apparent during the flow
monitoring period.
At several times during the data collection period the sensor was malfunctioning. It is
suspaceted that debris in the pipe impacted the senor affecting the data collection.
Further analysis of the theoretical flow and the recorded average wet-weather-flow it
appears that the Nelson Street at the Fire Station site sewershed accounts for more than
30% of the extraneous flow within the SPS No. 1 sewershed, approximately 818 m³/d.
This sewershed includes the Nelson Street and Cook Street site and the Nelson Street
and Noble Street site.
Appendix ‘C’
Flow Analysis
Page 8
Nelson Street and Noble Street Intersection
The Nelson Street and Noble Street site was the smallest sewershed of all the Flo-tote
sites. During spring snowmelt and runoff the flows were significantly higher than during
dry weather. Flow and level also increased dramatically following rainfall events. The
effects of rainfall did appear to be delayed, suggesting that the added flow can be
attributed to infiltration rather than inflow. During dry weather, the flows generated within
the sewershed were negligible
At several times during the data collection period the sensor was malfunctioning. It is
suspected that debris in the pipe impacted the senor affecting the data collection.
Susan Street and Sykes Street Intersection
The graph of Flo-tote data for the Susan Street and Sykes Street site showed similar
flow, level and velocity characteristics during both dry and wet weather. At times, flow
was so negligible that the sensor could not measure it. This sewershed was small and
infiltration appears to be minimal.
Flows increased dramatically during rainfall events.
experiences inflow as a direct result of rainfall events.
This suggests that this area
Computer Model (SewerCAD)
The entire sanitary sewer collection system was modelled using Heastad Methods’
SewerCAD modelling software. The model was constructed based on available record
drawing information. In some instances, either where data was unavailable or where the
modelling software’s capabilities could not accommodate certain system elements,
modifications had to be made to the model in order to allow it to function correctly. The
following paragraphs outline issues that arose during the construction of the model.
Syphon
The existing syphon, which passes under the Big Head River and leads to Sewage
Pumping Station No. 1 consists of two ductile iron pipes, one 150 mm and one 200 mm
in diameter. For the purpose of the computer model these pipes had to be modelled as
a single pipe. A 250 mm diameter ductile iron pipe was used as an equivalent since it
provides the same cross-sectional area as the existing two-pipe syphon.
Junction Chambers
SewerCAD does not allow for stubs to be modeled as part of the system. This limitation
in the software has been reported to Haestad Methods, the maker of SewerCAD. To
avoid the possible confusion that may occur by placing additional maintenance holes at
the end of every stub, we have used a “junction chamber” to designate a stub which has
been capped for possible future connection.
Appendix ‘C’
Flow Analysis
Page 9
Breaking Loops
SewerCAD does not allow for looped connections to be modeled as part of the sewer
system. Regardless of the elevations assigned to pipe inverts which would prevent
sewage flow to loop through the system without severe surcharging and backup in the
pipes, the model will not run correctly if a looped connection exists. Haestad Methods is
aware of this limitation and is working to correct it for future versions its software. In
order to overcome this limitation in the software, any existing “loops” where broken at
their perceived high point and, if required, an additional maintenance hole was inserted.
Breaks were required at three locations within the Meaford sewer collection system.
These locations are listed in Table 5:
Table 5 – Loop Breaks in Sanitary Sewer System
Location
Intersection of Meadow Lane and Fairway
Avenue – Maintenance Hole No. 35300
Intersection of St. Vincent Street and Bridge
Street – Maintenance Holes No. 11240 and
18400
Intersection of Union Street and Paul Street –
Maintenance Holes No. 11390 and 11400
Adjustment To Model
Break inserted into pipe and additional
maintenance hole added on Meadow Lane
Pipe removed from between Maintenance
Holes No. 11240 and 18400
Pipe removed from between Maintenance
Holes No. 11390 and 11400
Disconnected Maintenance Hole
According to Record Drawings a maintenance hole exists at the intersection of Owen
Street and Berry Street (Maintenance Hole No. 12830). This Maintenance Hole does
not appear to have been connected to the rest of the sewer collection system. We
recommend that it be checked in the field to confirm that indeed there is no flow passing
through it. For the purposes of the model Maintenance Hole No. 12830 was removed
from the system.
Unknown Rim Elevations
Where Record Drawing data was unavailable for existing maintenance hole rim
elevations, an elevation of 500 m was assigned. Rim elevation data is not required for
the model and has no effect on the results. However, as information becomes available
via future surveys it should be added to the SewerCAD model and the MS Access
record information database.
Drop Structures
An allowance for drop structures was made in the model at locations where Record
Drawings indicated that a drop structure exists. A note was also added to the
maintenance hole dialogue box.
Appendix ‘C’
Flow Analysis
Page 10
Slope and Pipe Invert Assumed Elevations
Where Record Drawing data was unavailable, pipe inverts and maintenance hole sump
elevations were assumed. Calculations were undertaken to determine approximate
elevations based on MOE minimum required slopes and surrounding elements for which
Record Drawing information was available.
Pipe Length and Diameter Assumed Values
Where Record Drawing data was unavailable, pipe lengths and diameters were
assumed. Pipe diameters where assumed based on the information available on the
overall Sanitary Sewer System drawing generated from the Original Base Map drawing
prepared by Gamsby and Mannerow Limited.
The modeling software was used to assign unknown pipe lengths and these lengths
were scaled off the model. It should be noted that the Original Base Map, which the pipe
layout in the model is based on, was generated from an uncontrolled mosaic based on
1989 assessment information. Following a comparison to record Drawings, it was
determined that the drawing scale was skewed and that information from the drawing
should only be used as a schematic representation of the sewer pipe network. As
further information is collected from future surveys the model and the MS Access
database should be updated.
The above sections represent a comprehensive flow analysis of the various
system drainage areas undertaken in 2004 to determine sections with significant
extraneous flows. More recent flow records were used to update the computer
model.
The recent flows were also compared with those from the 2004
investigation to determine if there were significant changes.
2010 UPDATE
Sewage Pumping Stations
The 2006 to 2009 sewage flow records for the five sewage pumping stations were
provided by the operator. This flow data is provided at the end of this appendix.
Dry and Wet Weather Flows
As per the 2004 investigation, dry and wet weather infiltration was determined for the
five sewage pumping stations by comparing the theoretical domestic sewage flow with
the recorded flows for August (dry) and March (wet).
Appendix ‘C’
Flow Analysis
Page 11
Sewersheds
The sewersheds represent the sub-drainage (service) areas for each pumping station.
Sewage Pumping Stations No. 1 – Bighead River:
In Table 1, recorded dry weather (August) and wet weather (March) flows for 2007 –
2009 are compared with the previous flow analysis.
Table 1 – SPS No. 1 Recorded Flows
Condition
Dry Weather
Wet Weather
2003
Recorded
Flow (m3/d)
1,330
3,704
2007
Recorded
Flow (m3/d)
1,459
3,748
2008
Recorded
Flow (m3/d)
1,616
3,072
2009
Recorded
Flow (m3/d)
1,336
3,709
Note that separation of several catchbasins from the sanitary sewage system was
undertaken on Edwin Street since the previous investigation.
Sewage Pumping Station No. 2:
Condition
Dry Weather
Wet Weather
2003
Recorded
Flow (m3/d)
134
554
2007
Recorded
Flow (m3/d)
123
514
2008
Recorded
Flow (m3/d)
175
416
2009
Recorded
Flow (m3/d)
261
601
Condition
Dry Weather
Wet Weather
2003
Recorded
Flow (m3/d)
129
437
2007
Recorded
Flow (m3/d)
126
433
2008
Recorded
Flow (m3/d)
-----
2009
Recorded
Flow (m3/d)
173
280
Sewage Pumping Station No. 4 services only one lot and the former Globe Mills site and
is not large enough to provide a valid comparative year-to-year data base.
Appendix ‘C’
Flow Analysis
Page 12
Sewage Pumping Station No. 4 services only three lots and the Meaford harbour, which
includes the Harbour Masters Office and the Canadian Coast Guard. This sewershed is
not large enough to provide a valid comparative year-to-year data base.
Summary Analysis:
Taking into account normal year-to-year variations and growth, the 2007 – 2009 dry and
wet weather flows are generally consistent with the flows recorded for the previous
investigation. The higher recorded flows from Sewage Pumping Station No. 2 may also
reflect recalibration of the flow meter, which was already allowed for in the 2004
computer model input data.
The flow records confirm that much of the corrective work identified in the 2004 field
investigation remains to be completed. Therefore, the majority of the input data
remained unchanged in the updated computer model. One significant reduction in the
model input value, however, was to the wet weather flows on Edwin Street where
separation of several catchbasins from the sanitary system was undertaken since the
previous investigation.
In the computer model, services connected between 2004 and 2010 and all future
service connections have been calculated based on the same parameters established in
the 2004 analysis, i.e. an occupancy factor of 2.4 and a flow of 450 L/cap/day multiplied
by the Harmon Peaking Factor plus standard allowance of 402.5 L/cap/day for inflow
and infiltration under wet weather conditions.
Appendix ‘C’
Flow Analysis
Page 13
Update
APPENDIX D: 2004 FIELD INVESTIGATION
Appendix ‘D’ Field Investigation
Report On
Sanitary Sewer Collection System Model
Appendix ‘D’ Field Investigation
Introduction
Areas of specific concern and interest to the Town were identified to be investigated
further in the field using the following techniques:
1)
2)
CCTV Inspection
Smoke Testing
These investigation techniques identified specific extraneous flow sources and sewer
components that were structurally deficient.
Pipe Vision prepared two CCTV reports, one for Susan Street and Helen Street and one
for Albert Street and William Street. These reports correspond to Tape #1 and Tape #2
respectively and summarise the findings of the CCTV inspection. Pipe Vision also
prepared a report summarizing the results of the smoke testing. All three reports and
the two videotapes are included as part of this report.
CCTV Inspection
Closed circuit television (CCTV) inspection is a widely used method of investigating
sanitary sewers. It can be used to identify structural problems in the pipe, including,
cracks, corrosion, collapses, etc., maintenance problems and reduced capacity due to
alignment, sediment deposition, mineral or grease deposits, roots, etc. and points of
infiltration.
The CCTV inspection involves sending a self-contained closed circuit television camera
along the sewer pipe between maintenance holes. The camera is driven through the
pipe by remote control. The video feed is sent to a truck, which follows the camera along
the surface. An operator in the truck can direct the camera to reverse and turn to better
view specific problem areas as required.
Pipe Vision carried out the CCTV inspections of various sewers as shown on drawing
103162-Video. Approximately 1,550 m or 5 % of the Town’s sanitary sewers were
CCTV inspected.
The CCTV inspection reports have been reviewed. There were several locations where
light encrustation or elevated water levels were observed. The Major problems identified
through these inspections have been summarized in the Table 1.
Table 1 – CCTV Inspection Results
Appendix ‘D’
Field Investigation
Page 1
Location
Problem
Albery Court
From MH 33200 to MH 33300 6.0 m
Albery Court
From MH 33300 to MH 33400 52.1 m
Albery Court
From MH 33400 to MH 33500 52.9 m
Albery Court
From MH 33500 to Buried MH 64.3 m
Albery Court
Between MH 33500 MH 33600 64.3 m
William Street
From MH 12901 to MH 12902 1.5 m
William Street
From MH 12901 to MH 12902 2.0
William Street
From MH 12890 MH 12900 10.4
William Street
From MH 12890 MH 11730 23.4 m
William Street
From MH 11730 MH 11720 13.9 m
Susan Street
From MH 32650 MH 32690 15.4 m
Susan Street
From MH 32650 MH 32690 1.6 m
Susan Street
From MH 32650 MH 32690 5.4 m
Susan Street
From MH 32650 MH 32690 17.2 m
Susan Street
From MH 32650 MH 32690 21.2 m
Susan Street
From MH 32650 MH 32690 46.7 m
Susan Street
From MH 32650 MH 32690 49.4 m
Susan Street
From MH 32650 MH 32690 49.4 m
Susan Street
From MH 32650 MH 32640 50.4 m
Susan Street
From MH 32640 MH 32650 7.5 m
Susan Street
From MH 32640 MH 32650 8.2 m
Susan Street
From MH 32640 MH 32630
Susan Street
From MH 32640 MH 32630
Susan Street
From MH 32640 MH 32630
Susan Street
From MH 32630 MH 32640
Susan Street
From MH 32630 MH 32640
Appendix ‘D’
Field Investigation
25.6 m
Longitudinal Crack
@ 9 o’clock
Stick blocking pipe at service
Severity
High
High
Debris (not grease or silt) collected in
pipe
Inspection was abandoned due to
debris filling 50% of pipe cross section.
Buried MH with major debris
Low
Pipe out of round
Medium
debris in the pipe
Debris collected at mouth of pipe
High
Medium
Broken pipe
High
debris filling more than 20% of the pipe
debris and high water level in the pipe
Displaced joint (large)
High
Displaced joint (medium)
Medium
Medium
Displaced joints continue throughout
Medium
Debris in pipe (not grease or silt)
Medium
Medium
debris filling more than 25% of the pipe
debris in the pipe
Heavy encrustation in bottom half of
pipe.
heavy encrustation in the bottom of the
pipe
pipe.
Infiltration dripping from top of pipe
High
High
High
High
High
Medium
Medium
High
Medium
High
25.6 m
26.3 m
pipe
High
Medium
Medium
1.5 m
8.7 m
Page 2
Location
Susan Street
From MH 32630 MH 32640
Susan Street
From MH 32630 MH 32621
Susan Street
From MH 32630 MH 32621
Susan Street
From MH 32630 MH 32621
Susan Street
From MH 32621 MH 32630
Susan Street
From MH 32621 MH 32630
Susan Street
From MH 32621 MH 32630
Susan Street
From MH 32621 MH 32630
Susan Street
From MH 32621 MH 32630
Susan Street
From MH 32660 MH 32620
Helen Street
From MH 34200 MH 34100
Helen Street
From MH 33800 MH 33900
Helen Street
From MH 33800 MH 33900
Problem
9.2 m
Severity
debris filling more than 40 % of the pipe
Stick in pipe from connection
High
pipe.
pipe
Defective connection, intruding into pipe
at 1 o’clock in pipe
Medium
Medium
35.5 m
49.9 m
50.2 m
2.1 m
High
High
Medium
2.7 m
3.0 m
debris in the pipe
High
Medium
4.1 m
18.5 m
Stick in pipe connection
High
Medium
Medium
High
High
4.7 m
72.4 m
59.9 m
59.9 m
The original CCTV inspection reports, complete with VHS videotapes, are included with
this report. It should be noted that although the reports for the CCTV inspection list the
linear measurements in feet that these measurements are actually in metres.
Smoke Testing
Smoke testing is a relatively quick and inexpensive method of sewer investigation. It is
used to detect sources of inflow such as connected storm water catch basins, roof
drains, driveway drains, abandoned or faulty service connections, and untrapped footing
drains. Smoke testing will not, however, identify connected drains if they are trapped or
if they are located below the water table.
A non-toxic and non-staining smoke is blown into an isolated section of sewer under low
pressure. Any smoke observed to be leaking from the system is indicative of a point of
inflow. These sources are investigated, photographed and recorded.
Pipe Vision carried out the smoke testing of various sewers as shown on drawing
103162-Smoke. Approximately 12,531 m or 40 % of the Town’s sanitary sewers were
smoke tested. There were many locations where smoke could not be seen exiting the
vent stack or the vent stack of the building. This is an indication that the service
connection between the main sewer line and the building may be blocked. This problem
is not of immediate concern but should be noted for future investigations.
Appendix ‘D’
Field Investigation
Page 3
Several major problems were identified during the smoke testing. These problems are
outlined in Table 2 and photos taken at the location of each problem are included in the
report prepared by Pipe Vision.
Table 2 – Major Problems Identified During Smoke Testing
Location
Helen Street
Between MH 33700 and 32880
Victoria Street
Trailer Park
113 Collingwood Street
Collingwood Street
St. Vincent Church
Between MH12020 and 12011
Cook and Collingwood Int.
West Corner
128 Cook Street
133 Cook Street
Cook and Nelson Intersection
East and west corners
128 Cook Street
112 Trowbridge Street
76 Trowbridge Street
66 Cook Street
43 Cook Street
189 Parker Street
49 Parker Street
3 Nelson Street
North side of road at church
North side of road at Dixie Lee
43 Collingwood Street
Overflow pipe to bay off Bayfield
Street
Garage roof on Parker Street
Appendix ‘D’
Field Investigation
Observation
Possible Problem
Main appears backed up
Blockage in sewer
Smoke emanating from ground
Break in pipe at two locations
Smoke emanating from vent
stack by window
Smoke emanating from roof
drain
Plumbing code violation
Smoke emanating from
catchbasin
Catchbasin connected to
sanitary sewer
catchbasin
catchbasin
catchbasins (2)
sanitary sewer
sanitary sewer
Catchbasins (2) connected to
sanitary sewer
catchbasin in yard
Smoke emanating from eves
trough
drain
Smoke emanating from pipe at
ground level
ground level
trough
trough
trough
catchbasin
catchbasin
trough
Smoke emanating from overflow
pipe outlet
sanitary sewer
Eves trough connected to
sanitary sewer
Roof drain connected to
sanitary sewer
Pipe at ground level
connected to sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
Tideflex Valve required at
overflow
drain
sanitary sewer
sanitary sewer
Page 4
Location
23 Parker Street
29 Parker Street
Auto Centre on Sykes Street
100 Sykes Street
98 Sykes Street
Royal Le Page on Sykes Street
94 Sykes Street
Noble Insurance on Sykes Street
Micro Trends on Sykes Street
88 Sykes Street
Crafters Gallery on Sykes Street
76 Sykes Street
Meaford Carpets on Sykes
Street
Observation
ground level
trough
Smoke emanating from vent
inside building
drain
drain
drain
drain
drain
drain
drain
drain
drain
drain
Possible Problem
sanitary sewer
Violation of the plumbing code
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
sanitary sewer
The actual Smoke Testing Report is included with this report.
Appendix ‘D’
Field Investigation
Page 5
Update
APPENDIX E: FUTURE DEVELOPMENT

- Municipality of Meaford

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