Environmental Management and Monitoring Report 1 July

Transcription

OLYMPIC DAM
Environmental Management
and Monitoring Report
1 July 2010 – 30 June 2011
Report No. ODENV 050
1 JULY 2010 - 30 JUNE 2011
BHP BILLITON OLYMPIC DAM
ENVIRONMENTAL MANAGEMENT AND MONITORING REPORT
OLYMPIC DAM
1 JULY 2010 - 30 JUNE 2011
The Hon. Tom Koutsantonis MP
Minister for Mineral Resources Development
PO Box 2832
ADELAIDE SA 5001
DISTRIBUTION
Department of Primary Industries
and Resources South Australia
(PIRSA)
Chief Inspector of Mines
1 CD copy
Department of Environment and
Natural Resources (SA)
CE Dept of Environment and Natural
Resources
1 CD copy
Senior Scientific Officer – Pastoral Land
Management – Land and Biodiversity
Services
Principal Scientific Officer – Pastoral
Program
1 CD copy
1 CD copy
CE Environment Protection Authority
1 CD copy
EPA Licence Coordinator
Manager Mining and Environment
Group Radiation Protection Branch
1 CD copy
1 CD copy
Department For Water (SA)
CE Dept For Water
Senior Hydrogeologist
1 CD copy
1 CD copy
Great Artesian Basin
Coordinating Committee
The Chair
1 CD copy
South Australian Arid Lands
Natural Resources Management
Board
The Chair
1 CD copy
Environment Protection
Authority (SA)
EXECUTIVE SUMMARY
Page i
1 JULY 2009 – 30 JUNE 2010
INTERNAL DISTRIBUTION
BHP Billiton Adelaide
BHP Billiton Olympic Dam
President Uranium
Vice President External Affairs
Corporate Lawyer
Vice President HSEC (Health,
Environment and Community)
Manager Sustainability
Manager Radiation Services
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1 CD copy
Asset President
Head of Production
General Manager Mine
General Manager Surface
General Manager Services
Head of HSEC
Manager Environment and Radiation
Superintendent Environment
Superintendent Radiation & Occupational
Hygiene
Environment Section Library
Records Centre
Page ii
Safety,
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2 hard copies
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2 hard copies
1 CD copy
EXECUTIVE SUMMARY
1 JULY 2010 - 30 JUNE 2011
Table of Contents
1 EXECUTIVE SUMMARY .......................................................................... 2 1.1 1.2 1.3 1.4 Overview.............................................................................................................. 2 Major Achievements ............................................................................................ 2 Monitoring Summary ........................................................................................... 2 Future Challenges ............................................................................................... 4 2 ENVIRONMENTAL MANAGEMENT PROGRAM (EMP)
IMPLEMENTATION ................................................................................. 5 2.1 2.2 2.3 2.4 2.5 2.6 2.7 ID 01 Use of Resources – Water ....................................................................... 10 ID 01 Use of Resources - Land ......................................................................... 11 ID 02 Operation of Industrial Systems – Airborne Emissions ............................ 18 ID 02 Operation of Industrial Systems – Hazardous Materials Spillage ............ 22 ID 03 Generation of Wastes – Tailings Storage System (TRS)......................... 25 ID 03 Generation of Wastes – General and Industrial Waste............................ 26 Conclusion ......................................................................................................... 28 3 GROUNDWATER MONITORING PROGRAM ....................................... 31 3.1 3.2 3.3 3.4 3.5 Groundwater Abstraction and Mine Water Balance .......................................... 31 Groundwater Levels .......................................................................................... 37 Groundwater Quality.......................................................................................... 44 Use of Mine Water for Dust Suppression .......................................................... 46 Conclusion ......................................................................................................... 48 4 GREAT ARTESIAN BASIN (GAB) WATER MONITORING
PROGRAM ............................................................................................. 49 5 FAUNA MONITORING PROGRAM ....................................................... 50 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Avifauna............................................................................................................. 50 Small Mammals and Reptiles ............................................................................ 52 Amphibians ........................................................................................................ 53 Feral and Abundant Species ............................................................................. 54 At-risk Species – Category 1a ........................................................................... 58 At-risk Species – Category 1b and 2 ................................................................. 60 Fauna Losses .................................................................................................... 62 Conclusion ......................................................................................................... 66 6 FLORA MONITORING PROGRAM ....................................................... 68 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Emission Impacts to Vegetation ........................................................................ 68 Long Term Changes to Perennial Vegetation ................................................... 71 Land Disturbance .............................................................................................. 74 Pest Plants ........................................................................................................ 77 GAB Spring Vegetated Wetland Area ............................................................... 87 At-risk Species – Category 1 ............................................................................. 88 At-risk Species – Categories 1b and 2 .............................................................. 91 Conclusion ......................................................................................................... 92 7 AIRBORNE EMISSIONS MONITORING PROGRAM ............................ 93 EXECUTIVE SUMMARY
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1 JULY 2009 – 30 JUNE 2010
7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 Smelter 2 Emissions .......................................................................................... 93 Calciner Emissions ............................................................................................ 95 Slimes Treatment Plant Emissions .................................................................... 96 Ambient Sulphur Dioxide (SO2) ......................................................................... 97 Fugitive Particulate .......................................................................................... 101 Results/Discussion .......................................................................................... 102 Raise Bore Ventilation Shaft Emissions .......................................................... 108 Conclusion ....................................................................................................... 110 8 ENERGY USE AND GREENHOUSE GAS EMISSIONS ..................... 111 8.1 8.2 8.3 Energy Use ...................................................................................................... 111 Greenhouse Gas Emissions ............................................................................ 112 Conclusion ....................................................................................................... 113 9 RADIATION DOSE TO MEMBERS OF THE PUBLIC
MONITORING PROGRAM .................................................................. 114 9.1 9.2 Dose to Members of the Public........................................................................ 114 Conclusion ....................................................................................................... 122 10 WASTE MONITORING PROGRAM .................................................... 123 10.1 10.2 10.3 10.4 10.5 10.6 10.7 Tailings Storage Facility (TSF) ........................................................................ 123 Evaporation Ponds (EPs) ................................................................................ 136 Mine Water Disposal Pond (MWDP) ............................................................... 141 Site and Olympic Village Sewage Ponds......................................................... 142 Waste Management Centre ............................................................................. 143 Miscellaneous Hazardous Wastes ................................................................... 144 Conclusions ..................................................................................................... 145 11 REFERENCES .................................................................................... 146 12 GLOSSARY OF TERMS ..................................................................... 149 13 APPENDIX 1: SUMMARY OF EXTERNALLY REPORTABLE
SPILLS ................................................................................................ 152 14 APPENDIX 2: METEOROLOGICAL DATA ....................................... 153 15 APPENDIX 4: CONSULTANTS UTILISED BETWEEN 1 July
2010 – 30 June 2011 ........................................................................... 156 Page iv
EXECUTIVE SUMMARY
1 JULY 2010 - 30 JUNE 2011
List of Figures
Figure 2-1: Figure 2-2: Figure 2-3: Figure 2-4: Figure 2-5: Figure 2-6: Figure 2-7: Figure 2-8: Figure 2-9: Figure 2-10: Figure 2-11: Figure 2-12: Figure 2-13: Figure 3-1: Figure 3-2: Figure 3-3: Figure 3-4: Figure 3-5: Figure 3-6: Figure 3-7: Figure 3-8: Figure 3-9: Figure 3-10: Figure 3-11: Figure 3-12: Figure 3-13: Figure 5-1: Figure 5-2: Figure 5-3: Figure 5-4: Figure 5-5: Rehabilitation of a road to the TSF5 soil stockpile ................................. 13 Contours are created in northern TSF5 soil stockpile to reduce
erosion and to help promote native vegetation growth .......................... 14 BEFORE – regenerated Athel Pines along Eagle way .......................... 15 AFTER – regenerating stumps were uprooted and left in situ ............... 15 Example of signage at Myall Grove drain outlet .................................... 16 June 2011 dashboard ............................................................................ 17 Total notifiable emissions trend ............................................................. 19 Salt damage to surrounding vegetation ................................................. 20 Site immediately after initial remediation works ..................................... 21 Vegetation recovering approx 12mths after initial remediation
work ....................................................................................................... 21 Number of radioactive process material spill events recorded in
each area FY07 to FY11. ....................................................................... 24 Area of liquor stored on TSF Cells 1 – 4 during FY11 ........................... 27 Olympic Dam site layout ........................................................................ 29 Olympic Dam regional bore locations .................................................... 32 Olympic Dam site area bore locations ................................................... 33 Simplified Olympic Dam hydrogeological cross-section ........................ 35 Site groundwater abstraction ................................................................. 36 Mine water balance summary FY11 (ML/d) ........................................... 37 TSF area groundwater levels (mAHD) - Andamooka Limestone
aquifer .................................................................................................... 39 Change in groundwater elevation along an east-west crosssection from LT19 to LT18, through the centre of the TSF .................... 40 Groundwater levels for Andamooka Limestone bores in the
vicinity of the TSF .................................................................................. 40 Groundwater levels for Andamooka Limestone bores in the
vicinity of Roxby Downs (LR) and the Mine Water Pond (LM) ............... 41 Groundwater levels for exploration drill holes in the vicinity of the
underground mine .................................................................................. 42 Mine area groundwater levels (mAHD) - Arcoona Quartzite
aquifer .................................................................................................... 43 Mine water sample 238U levels and upper limit, FY11 ............................ 47 Mine water sample 226Ra levels and upper limit, FY11 .......................... 48 Abundance of Crested Bellbirds (CBB) in each of the monitoring
zones (± 1 standard error). .................................................................... 51 Abundance of insectivorous feeding flock (IFF) species in each of
the monitoring zones (± 1 standard error).............................................. 51 Impact footprint of the bioindicator bird species during FY10 and
FY11 periods.......................................................................................... 52 Impact footprint of reptiles and small mammals during FY10 and
FY11 periods.......................................................................................... 53 Three sampling sessions moving average (per km2) for rabbit
abundance at three transects in the Olympic Dam region ..................... 56 EXECUTIVE SUMMARY
Page v
Figure 5-6: Figure 5-7: Figure 5-8: Figure 5-9: Figure 5-10: Figure 5-11: Figure 5-12: Figure 6-1: Figure 6-2:
Figure 6-3: Figure 6-4: Figure 6-5: Figure 6-6: Figure 6-7: Figure 6-8: Figure 6-9: Figure 6-10: Figure 6-11: Figure 6-12: Figure 6-13: Figure 7-1: Figure 7-2: Figure 7-3: Figure 7-4: Page vi
1 JULY 2009 – 30 JUNE 2010
Three sampling sessions moving average (per km2) for cat
abundance at three transects in the Olympic Dam region ..................... 57 Three sampling sessions moving average (per km2) for fox
abundance at three transects in the Olympic Dam region ..................... 57 Three sampling sessions moving average (per km2) for kangaroo
abundance at three transects in the Olympic Dam region ..................... 58 Monthly summary of weekly monitoring results for FY11, showing
total number of animals (birds, mammals and reptiles) recorded
within the TRS ........................................................................................ 63 Quarterly summary of all weekly monitoring results, showing total
number of animals (birds, mammals and reptiles) recorded within
the TRS .................................................................................................. 64 Monthly summary of opportunistic observation results for FY11,
showing total number of animals (birds, mammals and reptiles)
recorded within the TRS......................................................................... 64 Monthly summary of number of water birds recorded at local nontoxic water bodies in comparison to TRS during FY11 .......................... 65 Location of radial sample sites and front sites monitored in FY11 ......... 70 Modelled distribution of symptoms in FY11 in and about the
operation ................................................................................................ 71
Modelled surface of Simpson’s index. The contours represent the
modelled level of dominance based on the values from the
sample sites (red dots) ........................................................................... 74 Disturbance on the SML between June 2010 and July 2011 ................. 76 Athel Pine control efforts continued on the SML during FY11.
Seven regenerating Athel Pine plants were controlled along
Eagle Way. Photo taken 5 weeks after control efforts undertaken ........ 79 Control efforts of Innocent Weed within the Myall Grove reserve
during summer FY11. Example of ‘Noxious Weed’ signage
installed at earth drains in Roxby Downs, where Innocent Weed
infestations are known to occur.............................................................. 79 Distribution of Extreme and High risk weed species on the SML in
FY11....................................................................................................... 80 Distribution of weed species at Olympic Dam Village (within the
Municipal Lease) in FY11 ....................................................................... 81 Distribution of weed species in the Roxby Downs urban area (in
the Municipal Lease) in FY11................................................................. 82 Distribution of weed species in the Arid Recovery reserve in FY11 ....... 83 Distribution of weed species on Andamooka Station (including
Andamooka township) in FY11 .............................................................. 84 Distribution of weed species on Roxby Downs Station and Purple
Downs Station in FY11........................................................................... 85 Distribution of weed species on Stuarts Creek Station in FY11 ............. 86 Calciner particulate emissions sample run averages ............................. 96 Modelled maximum 1-hour average ground level SO2
concentration, FY11 ............................................................................... 98 Modelled maximum 24-hour average ground level SO2
concentration, FY11 ............................................................................... 99 Modelled average annual ground level SO2 concentration, FY11........ 100 EXECUTIVE SUMMARY
1 JULY 2010 - 30 JUNE 2011
Figure 7-5: Figure 7-6: Passive dust monitoring site locations ................................................. 103 Annual passive dust deposition rates measured at monitoring
sites, FY11 ........................................................................................... 104 Figure 7-7: Dust deposition rate by month at sites south of Olympic Dam ............ 105 Figure 7-8: Annual dust deposition rate for sites south of Olympic Dam ............... 105 Figure 7-9: Annual 238U deposition rates measured at monitoring sites, FY11 ...... 106 Figure 7-10: Annual 238U deposition rate by site ...................................................... 107 Figure 7-11: Modelled distribution of limestone dust deposition in FY11 ................. 108 Figure 7-12: Monthly average of daily salt deposition rate, at monitoring sites
100m from raise bore ........................................................................... 109 Figure 9-1: Environmental Radiation Monitoring Sites ........................................... 115 Figure 9-2: FY11 radon decay product monthly averages, including five-year
trends ................................................................................................... 117 Figure 9-3: 238U concentration for the previous 5 years (in TSP and PM10) ........... 118 Figure 9-4: 230Th concentration for the previous 5 years (in TSP and PM10) .......... 119 Figure 9-5: 226Ra concentration for the previous 5 years (in TSP and PM10) ......... 119 Figure 9-6: 210Pb concentration for the previous 5 years (in TSP and PM10) ......... 120 Figure 9-7: 210Po concentration for the previous 5 years (in TSP and PM10) ......... 120 Figure 9-8: Total TSP and PM10 concentration for the previous 5 years ................ 121 Figure 9-9: Total effective dose .............................................................................. 122 Figure 10-1: TSF Supernatant Pond areas .............................................................. 124 Figure 10-2: TRS aerial photograph – July 2011 ..................................................... 126 Figure 10-3: Tailings Solids, Liquor and Tailings Density as % Solids ..................... 127 Figure 10-4: TSF Cell 4 Underdrainage Pumping Rate ........................................... 128 Figure 10-5: Elevation of tailings in TSF cells .......................................................... 129 Figure 10-6: TSF Cells 1 – 4 Liquor Balance – Inputs, FY11 ................................... 130 Figure 10-7: TSF Cells 1 – 4 Liquor Balance – Outputs, FY11 ................................ 130 Figure 10-8: Location of perimeter features monitored regularly ............................. 132 Figure 10-9: Photo of location 3 in August 2011 showing buttress .......................... 133 Figure 10-10: Schematic cross section through south side of TSF Cell 1 – June
2011 ..................................................................................................... 133 Figure 10-11: TSF Cell 1 South Wall Piezometer Hydrographs ................................. 134 Figure 10-12: TSF Cell 3 daily seepage liquor flow.................................................... 134 Figure 10-13: TSF Cell 3 liquor analyses ................................................................... 135 Figure 10-14: Photograph of Location 13B looking North in July 2011 ...................... 136 Figure 10-15: EP1 and EP2 Liquor Balance – cumulative apparent evaporation
trends ................................................................................................... 138 Figure 10-16: EP3 Liquor Balance – cumulative apparent evaporation trend ............ 139 Figure 10-17: EP4 Liquor Balance – cumulative apparent evaporation trend ............ 139 Figure 10-18: EP5 Liquor Balance – cumulative apparent evaporation trend ............ 140 Figure 10-19: All EP Liquor Balance – cumulative apparent evaporation .................. 140 Figure 10-20: Evaporation pond capacity................................................................... 141 Figure 14-1: Annual rainfall FY11............................................................................. 153 Figure 14-2: Wind rose, FY11 .................................................................................. 154 Figure 14-3: Corrected Wind rose, FY10 ................................................................. 155 EXECUTIVE SUMMARY
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1 JULY 2009 – 30 JUNE 2010
List of Tables
Table 2-1: Table 2-2: Table 3-1: Table 3-2: Table 3-3: Table 5-1: Table 5-2: Table 5-3: Table 6-1: Table 6-2: Table 6-3: Table 6-4: Table 6-5: Table 6-6: Table 6-7: Table 7-1: Table 7-2: Table 7-3 Table 7-4: Table 8-1: Table 8-2: Table 10-1: Page viii
FY11 EMP Implementation Summary ...................................................... 6 Olympic Dam Progressive Rehabilitation conducted prior to FY11 ....... 12 Groundwater chemistry data for bores located in the vicinity of
Olympic Dam.......................................................................................... 45 Upper limits for radionuclide content in dust suppression water ............ 46 Radionuclide analysis for dust suppression water ................................. 47 Summary of rabbit, cat, fox and kangaroo numbers (per square
kilometre), showing historical abundance, FY10 and FY11 ................... 56 Cat stomach analysis results ................................................................. 58 Category 1b &2 species recorded in the Olympic Dam and
wellfields region for FY11 ....................................................................... 61 Areas of modelled impact for symptoms since FY07 and change
between FY10 and FY11 (areas modelled to the nearest 50ha) ........... 70 Changes in quadrat species counts FY10-11, for sites sampled in
both years (n=44 sites) .......................................................................... 73 Changes in the total number of plants FY07-11, for sites sampled
in over those years ................................................................................. 73 Areas of disturbance on the SML from June 2010 to July 2011 ............ 75 Pest plant species that pose an extreme or high risk ............................. 78 Changes in Eriocaulon carsonii abundance, FY10 – FY11
(n=131) ................................................................................................... 89 Changes in Eriocaulon carsonii abundance, baseline – FY11
(n=103) ................................................................................................... 90 Smelter 2 Stack Sampling Results June 2011 ....................................... 94 Measured particulate concentrations in Calciner Emissions
(mg/Nm3) ................................................................................................ 95 Classification of limestone dust deposition on ground surfaces ........... 101 Modelled impact footprint for limestone dust deposition and
change FY10-FY11 (areas modelled to the nearest 50 ha) ................. 107 Actual results of Energy Efficiency for June 2011 ................................ 111 Actual results of Carbon Equivalent Intensity for June 2011................ 113 List of perimeter features including their location, discovery date
and status............................................................................................. 131 EXECUTIVE SUMMARY
1 JULY 2009 – 30 JUNE 2010
1 EXECUTIVE SUMMARY
1.1 Overview
This report represents the first annual report under the approved three year FY11-FY13
Environmental Protection and Management Program (EPMP).
Considerable progress against actions and improvement targets in the FY11 EMP was
made during the reporting period, with 75 percent of actions completed. Actions not
completed during the reporting period will be progressed as a priority during FY12.
1.2 Major Achievements
Following is a list of major achievements for the reporting period:
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Reducing flow of water from pastoral bores by 4ML/d from the FY08 baseline;
Maintaining an industrial water efficiency of 1.12kL/t at an annual production rate of
10Mt;
Updating the existing hydrogeological model to include additional spring groups
and information from new monitoring bores;
The establishment of Energy and Water reduction cost curves to evaluate
abatement opportunities;
The establishment of Energy and Water Steering committees, with representatives
from all departments, to ensure a coordinated approach to energy and water
management across site;
Reviewing our Environment and Indigenous Heritage Clearance Permit procedure
to include the Native Vegetation Management Plan and Significant Environmental
Benefit requirements;
Update and submission to Government of the 2011 Closure and Rehabilitation
Plan;
Rehabilitation of TSF5 construction support areas; and,
Significant improvements in streamlining data collection of measurements of
energy and greenhouse gas emission data.
1.3 Monitoring Summary
During the reporting period, ongoing environmental monitoring activities were
undertaken. The following are points of interest:
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Peak groundwater level beneath the TSF for this reporting period was
approximately 67mAHD. Levels are not expected to exceed the limit of 80mAHD
(20m below the ground) within the next 12 months;
Slightly elevated concentrations of uranium continue to be detected in the
groundwater beneath the mine water disposal pond and old mine water disposal
pond. Measured values do not pose a health hazard due to the low concentrations
and the salinity of the water, which restrict its use for human or animal
consumption;
Radiation activity levels for dust suppression water were found to be consistent with
those measured in FY10 and were all below the upper limit values;
Avifauna indicators show that the operation appears to have measurable impacts in
close proximity to the operation. The extent appears similar to the previous year;
Gecko gravidity, reptile and small mammal indicators show that the operation
appears to have observed impacts when in close proximity to the operation. High
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EXECUTIVE SUMMARY
1 JULY 2010 - 30 JUNE 2011
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numbers of the introduced House Mouse influenced scores from small mammal
and reptile monitoring;
Kangaroo, rabbit and fox numbers were lower than the long term mean on all
transects;
Several Category 2 listed species were recorded in the Olympic Dam SML area
and the wellfields region. Three of the species recorded were within the TRS
system and several other waterbird species have the potential to visit this area;
There were 348 fauna mortalities recorded during weekly monitoring at the TRS in
FY11, which compares to 148 for the previous reporting period. This increase was
largely due to introduced house mice (over 100 recorded). The TRS Fauna project
continued in FY11;
The total area of detectable symptoms on vegetation for FY11 was 2,500ha. This is
100ha larger than that identified in FY10. Where areas were affected, there were
likely to be slightly fewer plant symptoms than in FY10;
The estimated total area of disturbance that occurred between June 2010 and July
2011 was 423.8ha;
Above average rainfall in the year preceding and during FY11 resulted in a high
number of pest plant infestations within the control area. Known infestation areas
were monitored and controlled with a focus on Extreme risk species;
Whilst there were some changes in Eriocaulon carsonii cover for individual spring
units between FY10 and FY11, the changes were not significant at the spring group
or impact zone level;
Isokinetic sampling of the Main Smelter Stack and Acid Plant Tail Gas Stack
indicated continued compliance with the requirements of EPA Licence 1301 and
the Environment Protection (Air Quality) Policy 1994;
The results of sampling indicate that emissions from Calciner A and B met the
requirements of the Environment Protection (Air Quality) Policy 1994;
No exceedance of the NEPM for ambient air quality for SO2 occurred over Olympic
Dam Village or Roxby Downs Township during the reporting period;
Dust and 238U deposition rates recorded during the reporting period were overall
lower than those measured in previous periods due to above average rainfall
throughout the year;
Salt deposition rates for RB10, RB16 and RB19 are comparable to previous
reporting periods. Deposition around RB21 increased during the first half of FY11,
but as a result of improvement works emissions have been significantly reduced for
the remainder of the year;
The site wide performance for GHG emissions in FY11 was 0.60GJ/t material
milled and 86kg CO2e/t material milled;
The dose to members of the public due to operation-related radon progeny at both
RDS and ODV were below the detection limit of 0.040mSv;
The dose to members of the public due to operation-related radionuclides in dust at
both RDS and ODV were below the detection limit of 0.008mSv;
An effective dose to members of the public of less than the detection limit of
0.048mSv/year was calculated when background dose calculations were
subtracted from measured doses. This value was less than 5% of the legislative
limit of 1mSv/year;
The region continued to experience above average rainfall during FY11 which has
resulted in the recording of some of the lowest PM10 and radionuclide
concentrations in recent history.
EXECUTIVE SUMMARY
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1 JULY 2009 – 30 JUNE 2010
Rainfall for the reporting period was 88% higher than the long term median annual
rainfall. As a result of the high rainfall and significantly higher tailings deposition,
the proportion of decant to evaporation ponds and liquor retained in tailings was
significantly higher than the previous reporting period;
The combined area of the supernatant ponds on TSF Cells 1–3 varied between
7.6ha and 25.0ha over the reporting period with an average of 15.6ha, an increase
of 84% from the previous years average of 8.5ha;
The supernatant pond area on TSF Cell 4 varied between 22.6ha and 42.5ha over
the reporting period with an average of 30.5ha, an increase of 68% from the
previous years average of 18.2ha;
A number of dark areas with increased moisture were identified previously around
the perimeter of the TSF and four additional areas have been identified in the
current reporting period;
A filter blanket was constructed over Location 3 on the South Wall of TSF Cell 1 to
minimise the risk of piping;
The results of the water balance indicate that the TSF has the capacity to dispose
of excess liquor by evaporation although the unaccounted liquor may also include
seepage from beach areas. Seepage from supernatant liquor ponds was estimated
at 3% of liquor output;
Evaporation Pond 2 was recommissioned in November 2010, following problems
with the wave barriers in the previous reporting period;
It is estimated that approximately 35,922m3 (loose fill) of general waste was
transported to the Waste Management Centre in FY11;
Approximately 787m3 of paper and cardboard waste was collected for recycling in
FY11; and,
It is estimated that approximately 7,917 tonnes of hazardous waste was disposed
of within the SML in FY11.
1.4 Future Challenges
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Continuing implementation of water use conservation and recycling initiatives,
including the substitution of saline water for high quality water use;
Continuing implementation of energy efficiency projects;
Continuing to develop the Smelter Environmental Improvement Plan with aims
to reduce the total smelter emission events;
Continuing investigations into management methods relating to interactions
between the TRS and fauna species;
Continuing to develop, update and implement a strategy towards minimising
radioactive waste produced from the mining and processing of ore;
Identifying further opportunities for improvement of general and industrial waste
management practices on site;
Integration of DEIS/SEIS approval conditions to the EPMP documents for next
Ministerial and Commonwealth Submission;
Preparation for a carbon price; and,
Streamlining data capture and reporting processes through the implementation
of a central environmental data management system (EDMS).
EXECUTIVE SUMMARY
1 JULY 2010 - 30 JUNE 2011
2 ENVIRONMENTAL MANAGEMENT PROGRAM (EMP)
IMPLEMENTATION
This section includes a summary of actions and improvement targets (Table 2-1)
identified for the financial year 2011 (FY11), from 1 July 2010 to 30 June 2011 under
the approved three years FY11-FY13 Environmental Management Program (EMP) for
Olympic Dam. Details of progress against these actions and improvement targets are
provided in Table 2-1.
The following progress indicators have been used to assist the reader in being able to
quickly assess progress that has occurred during the reporting period:
=
Activity or target achieved
=
Significant progress towards achieving the activity or target
=
Activity or target not achieved.
The approved FY11 EMP contained 68 actions with improvement targets to be
achieved during the year.
The performance against these commitments was:
= 75%
= 9%
= 16%
A plan showing the areas of the Olympic Dam site discussed in this report is provided
in Figure 2-13.
ENVIRONMENTAL MANAGEMENT PROGRAM (EMP) IMPLEMENTATION
Page 5
Table 2-1:
1 JULY 2009 – 30 JUNE 2010
FY11 EMP Implementation Summary
ID 01 Use of Resources - Water
ID 1.1 Great Artesian Basin (GAB) Pressure Reductions
Targets FY11:
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Reduce Etadunna and Muloorina West pastoral flows by 4ML/day from the FY08 baseline
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Maintain an industrial water efficiency of 1.12kL/t at an annual production rate of 10Mt.
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Maintain a domestic water use target of 2.6ML/day.
Action Plan FY11:
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Remove Jackboot Bore as an assessment criteria monitoring point.
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Update the existing GAB hydrogeology model based on new information and review of
existing technical information.
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Continue implementation of water use conservation and recycling initiatives.
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Continue substitution of saline water for high quality water use.
ID 01 Use of Resources – Land
ID 1.2 Land Disturbance and Rehabilitation
Targets FY11:
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Review EIHCP procedure to include requirements of the SEB NVMP.
Action Plan FY11:
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Identify and prioritise projects to clarify high risk assumptions identified in Olympic Dam
Rehabilitation and Closure Plan.
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Continue EIHCP awareness sessions with influencing personnel and contractors as
required.
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Continue to implement the site rehabilitation strategy.
ID 1.3 Spread of Pest Plants
Targets FY11:
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Eradicate Athel Pines along Eagle Way on the SML through mechanical removal where past
control efforts are deemed unsuccessful.
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Install signage at drain culverts where declared pest species are found.
Action Plan FY11:
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Continue to monitor and control all known Innocent Weed infestation. Address any new
infestations of Innocent Weed as required.
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Continue to progress control of Buffel Grass within the SML and Municipal Lease.
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Continue to progress control of Athel Pines within the SML and at the Olympic Dam
Aerodrome.
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Continue to improve community knowledge of local pest plant species.
ID 01 Use of Resources – Energy and Greenhouse Gas Emissions
ID 1.4 Climate Change
Targets FY11:
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To be developed by the Energy Excellence Program during FY10 and reported through the
Olympic Dam Dashboard.
Action Plan FY11:
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Continue implementation of the energy efficiency projects.
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Improve energy and greenhouse gas emission data collection and measurement.
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Continue to establish and embed sound energy excellence procedures and systems.
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1 JULY 2010 - 30 JUNE 2011
ID 02 Operation of Industrial Systems – Airborne Emissions
ID 2.1 Sulphur Dioxide Emissions
Targets FY11:

Reduce unplanned Acid Plant bypass events by 5% of the FY10 target (to less than or equal
to 14 events).

Maintain Acid Plant Tails Gas Stack exceedances at the FY10 target (to less than or equal
to 16 events).

Reduce the total unplanned emission events by 5% of the FY10 target (less than or equal to
78 events).
Action Plan FY11:

Implement the Smelter/Refinery Environmental Improvement Plan.

Identify reductions to SO2 emissions after the Smelter maintenance shutdown.
ID 2.2 Particulate Emissions
Targets FY11:

Maintain annual average operational contributed PM10 concentration at sensitive receptors
at equal or below the assessment criteria (ID2.2 – 7).
Action Plan FY11:

Continue with the annual Processing Environmental Improvement Plan process.

Continue with the annual Mining Environment Improvement Plan process.
ID 2.3 Saline Aerosol Emissions
Targets FY11:

Reduction in the deposition of salt (NaCl) from saline aerosol emissions at RB21 salt jars by
25% from the 2009 annual average (less than 1,066mg/m2/day).
Action Plan FY11:

Remediate areas of saline contamination around RB21

Develop criteria for saline emission controls at raise bores and ensure future changes to
controls meet the criteria

Install and repair fencing barricades to high priority raise bores according to the action plan
developed in Q3 FY10.
ID 2.4 Radioactive Emissions
Targets FY11:

Annual operational component of radiation doses to members of the public remain below 0.3
mSv.
Action Plan FY11:

Continue with Monitoring Program Airborne Emissions FY11-13 and Radiation Dose to
Members of the Public FY11-13.
ID 02 Operation of Industrial Systems – Hazardous Materials Spillage
ID 2.5 Chemicals/Hydrocarbon Spills
Targets FY11:

Concentrator – recordable spills of chemicals and hydrocarbons less than or equal to 4.

Hydromet – recordable spills of chemicals and hydrocarbons less than or equal to 3.

Smelter – recordable spills of chemicals and hydrocarbons less than or equal to 5.

Refinery – No recordable spills of chemicals and hydrocarbons.

Infrastructure – recordable spills of chemicals and hydrocarbons less than or equal to 3.

Mine – recordable spills of chemicals and hydrocarbons less than or equal to 14.

Supply – recordable spills of chemicals and hydrocarbons less than or equal to 1.
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1 JULY 2009 – 30 JUNE 2010
Action Plan FY11:

Undertake annual site chemical/hydrocarbon audit and implement actions from this audit
with regards to bunding criteria and implementation.
ID 2.6 Radioactive Process Material Spills
Targets FY11:

Concentrator – reduce recordable spills of radioactive process material by 10% of the FY10
target (to less than or equal to 14 spills).

Hydromet – maintain recordable spills of radioactive process material at the FY10 target (to
less than or equal to 18 spills).

Smelter – reduce recordable spills of radioactive process material by 10% of the FY10 target
(to less than or equal to 11 spills).

Refinery – maintain recordable spills of radioactive process material at the FY10 target (to
less than or equal to 6 spills).

Infrastructure – maintain recordable spills of radioactive process material at the FY10 target
(less than or equal to 4 spills).

Mine – maintain recordable spills of radioactive process material at the FY10 target (less
than or equal to 5 spills).
Action Plan FY11:

Continue with the annual Processing Environmental Improvement Plan process.

Continue with the annual Smelter/Refinery Environmental Improvement Plan process.

Continue with the annual Mining Environmental Improvement Plan process.

Develop an annual Infrastructure Environmental Improvement Plan.
ID 03 Generation of Wastes – Tailing Storage System (TRS)
ID 3.1 Embankment Stability
Targets FY11:

Review the slope stability around the perimeter of TSF Cells 1-4 using actual measured pore
pressure distributions and confirm the factors of safety for embankment stability.

Install a buttress and filter at the toe of the western embankment of TSF Cell 3 and the
adjacent eastern section of the northern embankment of TSF Cell.
Action Plan FY11:

Prepare a report on the embankment stability of TSF Cells 1 to 4 using actual pore pressure
monitoring data.

Complete the detailed design and construction of a buttress and filter at the toe of the
western embankment of TSF Cell 3 and adjacent eastern section of the northern
embankment of TSF Cell 4.

Install de-watering bore in spine of cells 3/4 to try to intercept liquor.
ID 3.2 Seepage
Targets FY11:

The groundwater level in the Andamooka Limestone aquifer outside the perimeter of TSF
Cells 1 to 4 shall not rise above 80 metres AHD.
Action Plan FY11:

Identify and install additional liquor interception systems if required.
ID 3.3 Fauna Interaction
Targets FY11:

Initiate assessment of the potential for Sound ID as an on demand deterrent system.

Initiate assessment of the durability of the HDPE balls and netting within the TRS.
Action Plan FY11:

Continue trials of Sound ID acoustic recognition systems.
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1 JULY 2010 - 30 JUNE 2011

Continue trials of HDPE netting and balls within the TRS.
ID 03 Generation of Wastes – General and Industrial Waste
ID 3.4 Solid Waste (Non Hazardous and Hazardous)
Action Plan FY11:

Improve data availability and integrity for tracking of wastes from source to disposal.

Set targets for waste recycling based on collected data.
ID 3.5 Radioactive Waste
Targets FY11:

Maintain the area of liquor stored in the TRS below or equal to 22ha as a monthly average.
Action Plan FY11:

Continue to develop, update and implement a strategy towards minimising radioactive waste
produced from the mining and processing of ore.
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2.1 ID 01 Use of Resources – Water
2.1.1 ID 1.1 Great Artesian Basin (GAB) Pressure Reductions
Targets FY11:

Reduce Etadunna and Muloorina West pastoral flows by 4ML/day from
the FY08 baseline.
Following the purchase of Etadunna and Muloorina West in 2009, pastoral flow rates
have been reduced in an effort to conserve water. Flow rates from pastoral bores on
these leases equalled 5.42ML/day in FY08. Flow rates measured during FY11 equalled
1.30ML/day – a reduction of 4.12ML/day over the period.

Maintain an industrial water efficiency of 1.12kL/t at an annual
production rate of 10Mt.
The GAB Industrial Water Efficiency of the operation in FY11 was 1.07kL/t. Production
for the year (total material milled) was 10.5Mt.
The achievement of 1.07kL/t equalled FY09 as the most water efficient year on record
for the operation.

Maintain a domestic water use target of 2.6ML/day.
Domestic water consumption for FY11 averaged 2.11ML/day, which achieved the
target.
Action Plan FY11:

Remove Jackboot Bore as an assessment criteria monitoring point.
Jackboot bore was removed as an assessment criteria monitoring point for Wellfield A
for the FY12 reporting period, however it still applies to Wellfield B. Discussions are
continuing regarding a proposal for the Ongoing Sustainable Management for the GAB
and part of this includes identifying alternative monitoring points.

Update the existing GAB hydrogeology model based on new
information and review of existing technical information.
Numerical models have been used for more than 15 years to simulate groundwater
flow in the south-west Great Artesian Basin (GAB) and the influence of the wellfields
supplying water to Olympic Dam and Roxby Township. Several groundwater models
have been created, from the initial GAB95 model, through successive improvements
and more and better data to the ODEX model families.
The following improvements were completed during the reporting period:

ODEX6 was created to distinguish the new model from the previous version
(ODEX5).

The ODEX6 model domain was extended to include the western springs, from
Anna to Strangways; and to place new information from the new monitoring
bores MB5 and MB6 into better hydrogeological context.
•
The ODEX6 model was reviewed and enhanced between Jackboot Bore and
the western springs to improve drawdown predictions. New bore data and the
results of recent hydrostratigraphic and geophysical work were included to the
west of Jackboot Bore.
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1 JULY 2010 - 30 JUNE 2011

•
Monitoring (drawdown data) and abstractions, including pastorals and Moomba,
were updated to June 2011.
•
The time periods ODEX6 uses were improved to better reflect the changes in
wellfield abstractions related to the Clark Shaft outage.
Continue implementation of water use conservation and recycling
initiatives
Implementation of the following water conservation and recycling initiatives began in
FY11 and are expected to reduce water use in FY12:



Increasing the equipment capacity for recycling of tailings liquor to the
metallurgical plant
Covering an open water storage at the desalination plant to reduce evaporative
losses
Continue substitution of saline water for high quality water use.
Saline water continues to be used in lieu of high quality water where feasible, including
use in CAF, road watering and construction.
Saline water is not being used to augment the process water stream as this results in
an unacceptable increase in chloride in the system, which effects plant performance.
Research is continuing into overcoming the technical barriers of high chloride in the
system and its negative impact.
Implementation began on a project which will use saline water as a substitute for high
quality water at the Mine vehicle wheelwash.
2.2 ID 01 Use of Resources - Land
2.2.1 ID 1.2 Land Disturbance and Rehabilitation
Targets FY11:

Review EIHCP procedure to include requirements of the SEB NVMP
The Environmental and Indigenous Heritage Clearance Permit (EIHCP) procedure was
reviewed to improve the efficiency of the process and to include requirements of the
Significant Environmental Benefit (SEB) Native Vegetation Management Plan (NVMP)
in FY11. Key outcomes from the review have resulted in:




Identification of areas subject to a SEB offset;
The addition of a SEB ratio attribute to the EIHCP spatial database;
Identification of process improvements to automate SEB offset accounting; and,
Identification of the requirement for a robust process and field guide for
assessing SEB ratios.
Continuous improvement will continue in FY12 to further improve the SEB accounting
process by developing an assessment field guide and by further integrating SEB
accounting requirements into the EIHCP and reporting procedure.
Action Plan FY11:

Identify and prioritise projects to clarify high risk assumptions
identified in Olympic Dam Rehabilitation and Closure Plan.
As part of updating Olympic Dam’s Closure and Rehabilitation Plan, the Life of Asset
(LOA) Plan has been used to derive key assumptions in calculating the provision for
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1 JULY 2009 – 30 JUNE 2010
closure costs. Some of the assumptions applied in the Closure Plan were derived from
the LOA Plan, namely:





The estimated life of the mine;
The useful life of the site plant and equipment as suggested in the LOA Plan;
Closure measures area referenced in the FY11 LOA Plan and defined in the
Olympic Dam Closure Plan 2007. The FY12 Life of Asset Plan will reference
closure measures as defined in the Olympic Dam Closure and Rehabilitation
Plan 2011 – Submitted to Government (PIRSA) in August 2011;
Rehabilitation activities conducted in FY11 will be reported in the FY12 Life of
Asset Plan; and,
Table 2-2 was provided by the Environment and Radiation Section for the
Progressive Rehabilitation Plan document in May 2011.
Table 2-2:
Olympic Dam Progressive Rehabilitation conducted prior to FY11
Facility
Description
Area Rehabilitated
Borefield Facilities
Disturbance from the construction of
the GAB water pipeline
365.6ha
Exploration
Borrow pits, Drill pads, turkey nest
14.0ha
Metallurgical Facilities
Unsealed road and mullock pile
6.4ha
Tailings Facilities
Unsealed road
0.5ha
Miscellaneous Facilities
Borrow pits, unsealed roads and other
disturbances
28.0ha
Town Facilities
Unsealed roads, Olympic Dam Camp 1
and Camp E
26.1ha
TOTAL

440.6ha
Note: Additional rehabilitation was undertaken of TSF5 stockpile areas and other areas no longer
required. Rehabilitation of these areas took place following the submission of the Closure and
Rehabilitation Plan and are not included in the table above.
The FY11 Annual Closure and Rehabilitation Plan review included a Closure Planning
Workshop in March 2011 and Risk Assessment Workshop in June 2011. These
workshops were held with the relevant internal stakeholders.
The following changes were considered to update the Closure Economic Evaluation
and associated Closure Risk Register:

The mine closure date was decreased from 2084 to 2082;

No changes to Life of Asset tailings cells were required; and,

The FY12 Life of Asset Plan will update any changes.
The Annual Closure Summary Report was completed by the Olympic Dam Resources
Planning and Development and Finance Departments and sent to BHP Billiton
Corporate.

Continue EIHCP awareness sessions with influencing personnel and
contractors as required.
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1 JULY 2010 - 30 JUNE 2011
EIHCP awareness sessions, with current information, were undertaken with key
personnel and contractors. This included presentations to influencing personnel from
the TSF5 construction crew, mine projects, services, exploration and drilling, and
backfill. Sessions will continue throughout FY12.

Continue to implement the site rehabilitation strategy.
With the underground nature of the operation and awareness of a possible future
expansion, large scale rehabilitation works were not undertaken during FY11. EIHCP
conditions require temporary disturbances to be rehabilitated where possible. This is
the case for excavation works to lay cable or fix burst pipes where topsoil is respread
and the earth lightly ripped to promote natural revegetation.
All areas cleared for the construction of TSF5 that are no longer required for ongoing
operation have been rehabilitated. This includes adding bunds into long term stockpiles
to prevent erosion and ripping up compacted laydown areas (Figure 2-1 to Figure 2-2).
Figure 2-1:
Rehabilitation of a road to the TSF5 soil stockpile
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Figure 2-2:
1 JULY 2009 – 30 JUNE 2010
Contours are created in northern TSF5 soil stockpile to reduce
erosion and to help promote native vegetation growth
2.2.2 ID 1.3 Spread of Pest Plants
Targets FY11:

Eradicate Athel Pines along Eagle Way on the SML through
mechanical removal where past control efforts are deemed
unsuccessful.
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1 JULY 2010 - 30 JUNE 2011
Seven regenerating Athel Pine trees were up-rooted along Eagle Way during FY11.
Past cut and swab control efforts were unsuccessful, so mechanical removal was
instigated and no regeneration has been noted since. Trees ranged from 1m to 3m in
height and were removed from the ground using a small excavator. Figure 2-3 and
Figure 2-4 show before and after photos of Athel Pine removal efforts.
Figure 2-3:
BEFORE – regenerated Athel Pines along Eagle way
Figure 2-4:
AFTER – regenerating stumps were uprooted and left in situ

Install signage at drain culverts where declared pest species are
found.
Signage displaying information regarding the presence of noxious weeds were installed
at four earth drain heads within Roxby Downs, in consultation with the Roxby Downs
Municipal Council. Signs were installed where infestations of Innocent Weed were
known to occur and there was a risk of contaminated soil being removed for
maintenance requirements (Figure 2-5).
Page 15
Figure 2-5:
1 JULY 2009 – 30 JUNE 2010
Example of signage at Myall Grove drain outlet
Action Plan FY11:

Continue to monitor and control all known Innocent Weed infestations.
Address any new infestation of Innocent Weed as required.
Innocent weed was present at known infestation locations during the summer of FY11.
Extensive physical and chemical control was undertaken on numerous occasions.
Despite flooding of several drainage areas where Innocent Weed occurs during FY10
and the substantial rainfall throughout FY11, the Myall Grove infestation area appeared
to be smaller and less dense than in previous years. Infestations found in earth drains
that run into the larger Myall Grove reserve area continue to be actively controlled as a
priority.

Continue to progress control of Buffel Grass within the SML and
Municipal Lease.
During FY11 Buffel Grass was monitored and controlled, using a combination of spot
spraying and hand-pulling. The distribution of this weed has in the past been largely
limited to the northern sections of Roxby Downs, particularly around the town water
supply and light industrial area. During FY11, infestations of significant size were
controlled along B97 Highway (Woomera to Olympic Dam). Individual infestations
continue to be controlled on the Special Mining Lease and appear to be decreasing in
density. Opportunistic monitoring, especially following rain, will continue in FY12.

Continue to progress control of Athel Pines within the SML and at the
Olympic Dam Aerodrome.
Progress of Athel Pine control is detailed in the ‘Targets FY11’ section of ID 1.3, above.

Continue to improve community knowledge of local pest plant species.
During FY11, articles on ‘Pest Plants’ and the use of ‘native species’ for landscaping
were submitted and published in local newspapers. Internal BHP Billiton notifications
were also sent in relation to common weed species following the substantial rainfall
events throughout FY11. Two Weed Management Group meetings were held during
FY11, attended by regional stakeholders and government representatives.
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2.2.3 ID 01 Use of Resources – Energy & Greenhouse Gas Emissions
2.2.4 ID 1.4 Climate Change
Targets FY11:

To be developed by the Energy Excellence Program during FY10 and
reported through the Olympic Dam Dashboard.
Targets for energy efficiency and greenhouse gas emissions (carbon equivalent
intensity) were set for each month and reported through the Olympic Dam dashboard.
Figure 2-6 shows the June 2011 results as an example. It gives the June actuals and
targets and the year to date (YTD – i.e. overall result for 2011) actuals and targets.
Figure 2-6 shows that overall site was close to target for energy efficiency and carbon
equivalent intensity. Some of the individual plant areas achieved target and some were
over target.
Figure 2-6:
June 2011 dashboard
The reason targets were not met was more related to the quality of targets, rather than
a reflection of performance. FY11 was the first year targets were set in this way, since
then the understanding of the drivers of energy use and greenhouse gas emissions has
improved. These learnings will be applied when setting future targets.
Action Plan FY11:

Continue implementation of the energy efficiency projects.
Progress was made on projects that had an energy benefit in FY11. This was
documented as part of the requirements of the federal government’s Energy Efficiency
Opportunities (EEO) legislation.

Improve energy and greenhouse gas emission data collection and
measurement.
Significant improvements in streamlining data collection and measurements were made
in FY11. This has reduced the time for the collation of routine monthly reports from a
full day to several hours. Changes have also resulted in improved accuracy of
departmental energy use and greenhouse gas emissions and for site as a whole. This
in turn has facilitated a better understanding of the drivers of variation in energy use
and greenhouse gas emissions.

Continue to establish and embed sound energy excellence procedures
and systems.
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1 JULY 2009 – 30 JUNE 2010
Existing procedures covering the monitoring of energy use and greenhouse gas
emissions, and the energy and greenhouse gas management plan were reviewed and
updated.
An Energy Steering Committee was formed and imbedded in FY11, which brings
together key personnel from across site to coordinate improvement actions and drive
accountability for energy performance. The committee is chaired by the Manager –
Environment and Radiation.
2.3 ID 02 Operation of Industrial Systems – Airborne Emissions
2.3.1 ID 2.1 Sulphur Dioxide Emissions
Targets FY11:

Reduce unplanned Acid Plant bypass events by 5% of the FY10 target
(to less than or equal to 14 events).
In FY11 a change was made to the way emission events were tracked and reported.
This change was made in order to shift the focus on reducing overall notifiable
emission events. This was done by reviewing the internal definition around planned
and unplanned events and tracking our total notifiable events rather than unplanned
events. As a result of this change a target for total notifiable Acid Plant bypass events
was determined.
The FY11 target for Acid Plant bypass events was 23. This represents both unplanned
and planned events. Actual number of Acid Plant bypass events in FY11 was 46. This
represents a 100% increase in the target number.

Maintain Acid Plant Tails Stack exceedances at the FY10 target (to less
than or equal to 16 events).
Acid Plant Tails Stack exceedances were 119% above target, with 35 events recorded.

Reduce the total unplanned emission events by 5% of the FY10 target
(less than or equal to 78 events).
In FY11 a change was made to the way emission events were tracked and reported.
This change was made in order to shift the focus on reducing overall notifiable
emission events. This was done by reviewing the internal definition around planned
and unplanned events and tracking our total notifiable events rather than unplanned
events. As a result of this change a target for total notifiable emission events was
determined based on a 5% reduction of the FY04-09 average.
The FY11 target for total notifiable emission events was 196. The actual result for FY11
was 194 total notifiable emission events, which is under target. (Figure 2-7). When
compared with the total emissions from FY09, this is a 25% reduction in the total
number of emissions notifiable to Government. Because FY10 does not represent a full
production year, the data has been compared with the FY09 period.
Page 18
1 JULY 2010 - 30 JUNE 2011
Number of emission events
300
250
200
150
100
50
0
FY06
FY07
Total Notifiable Emission Events
Figure 2-7:
FY08
FY09
Acid Plant Tails Stack Exceedances
FY10
FY11
Acid Plant Bypass Events
Total notifiable emissions trend
Action Plan FY11:

Implement the Smelter/Refinery Environmental Improvement Plan.
An action plan was developed and implemented throughout FY11. This was reviewed
periodically and most actions deemed relevant were completed during FY11. The few
outstanding actions will be considered in the FY12 EIP process. A significant focus was
put in by the operations area in the EIP to reduce bypass events associated with the
anode furnace off gas area. As a result a large reduction in emissions was observed
during FY11 from this area.

Identify reductions to SO2 emissions after the Smelter maintenance
shutdown.
As a result of the Smelter maintenance shutdown that occurred in FY10 a decrease in
emissions was not observed. Due to equipment being offline for an extended period of
time, emission events increased due to a failure with the variable speed drive on the
anode furnace four off-gas fan.
2.3.2 ID 2.2 Particulate Emissions
Targets FY11:

Maintain annual average operational contributed PM10 concentration
at sensitive receptors at equal or below the assessment criteria (ID2.2
– 7).
Annual average PM10 concentrations at Olympic Dam Village (ODV) and Roxby
Downs (RDS) for FY11 were below 30µg/m3. PM10 concentrations peaked in
September 2010 at ODV and RDS, at 18µg/m3 and 25µg/m3, respectively. Annual
average concentrations for ODV and RDS were 10.5µg/m3 and 11.1µg/m3,
respectively.
Action Plan FY11:

Continue with the annual Processing Environmental Improvement Plan
process.
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1 JULY 2009 – 30 JUNE 2010
outstanding actions will be considered in the FY12 EIP process.

Continue with the annual Mining Environment Improvement Plan
process.
An EIP for the mine has been initiated, focusing on saline aerosol emissions from raise
bores and improving controls as well as hydrocarbon management. Outstanding
actions will be considered in the FY12 EIP process.
2.3.3 ID 2.3 Saline Aerosol Emissions
Targets FY11:

Reduction in the deposition of salt (NaCl) from saline aerosol
emissions at RB21 salt jars by 25% from the 2009 annual average (less
than 1,066mg/m2/day).
The RB21 mist eliminators were repaired in January 2010, which substantially reduced
salt emissions. The FY11 annual average RB21 salt deposition result was
358mg/m2/day. RB21 salt deposition peaked in February 2011 at 1,220mg/m2/day.
Action Plan FY11:

Remediate areas of saline contamination around RB21.
During FY11 contaminated soil was removed from the eastern area surrounding RB21.
Following substantial rainfall throughout the reporting period, annual and some
perennial vegetation has re-established in areas previously impacted from salt
deposition, see Figure 2-8, Figure 2-9 and Figure 2-10 below.
Figure 2-8:
Page 20
Salt damage to surrounding vegetation
1 JULY 2010 - 30 JUNE 2011
Figure 2-9:
Site immediately after initial remediation works
Figure 2-10: Vegetation recovering approx 12mths after initial remediation work

Develop criteria for saline emission controls at raise bores and ensure
future changes to controls meet the criteria.
Saline emission controls at raise bores have been identified and are currently being
tested. Suggested controls are the installation of mist eliminators and cement wall
fencing around barricades. An investigation is currently underway with a contract
company to upgrade the mist eliminators and increase the raisebore fan performance,
therefore reducing the need for strenuous maintenance caused by the current
maintenance regime. Further investigation will also focus on the possibility of using
shade cloth as an extra emission prevention device by extending it from the top of the
concrete barriers to the top of the fan outlet.

Install and repair fencing barricades to high priority raise bores
according to action plan developed in Q3 FY10.
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1 JULY 2009 – 30 JUNE 2010
The installation of cement barricades to high priority raise bores are tracking well within
the set timeframes, with no major problems.
2.3.4 ID 2.4 Radioactive Emissions
Targets FY11:

Annual operational component of radiation doses to members of the
public remain below 0.3mSv.
Operational component of radiation doses to members of the public at Olympic Dam
and Roxby Downs remained below the detection limit of 0.048mSv/year.
Action Plan FY11:

Continue with Monitoring Program Airborne Emissions FY11-13 2788
and Radiation Dose to Members of the Public FY11-13 2790.
Monitoring programs continue to be executed without any changes.
2.4 ID 02 Operation of Industrial Systems – Hazardous Materials
Spillage
2.4.1 ID 2.5 Chemicals/Hydrocarbon Spills
Targets FY11:

Concentrator – recordable spills of chemicals and hydrocarbons less
than or equal to 4.
Recordable spills of chemicals and hydrocarbons in the Concentrator were 25% above
target with 5 events recorded in FY11.

Hydromet – recordable spills of chemicals and hydrocarbons less than
or equal to 3.
Recordable spills of chemicals and hydrocarbons in the Hydromet were 100% below
target with no events recorded in FY11.

Smelter – recordable spills of chemicals and hydrocarbons less than
or equal to 5.
Recordable spills of chemicals and hydrocarbons in the Smelter were 20% below target
with 4 events recorded in FY11.

Refinery – no recordable spills of chemicals and hydrocarbons.
Recordable spills of chemicals and hydrocarbons in the Refinery were above target
with 2 events recorded in FY11.

Infrastructure – recordable spills of chemicals and hydrocarbons less
than or equal to 3.
Recordable spills of chemicals and hydrocarbons in Services were above target with 4
events recorded in FY11.

Mine – recordable spills of chemicals and hydrocarbons less than or
equal to 14.
Recordable spills of chemicals and hydrocarbons at the Mine were below target with 5
events recorded.
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1 JULY 2010 - 30 JUNE 2011

Supply – recordable spills of chemicals and hydrocarbons less than or
equal to 1.
Recordable spills of chemicals and hydrocarbons in Supply were above target with 2
events recorded in FY11.
Action Plan FY11:

Undertake annual site chemical/hydrocarbon audit and implement
actions from this audit with regards to bunding criteria and
implementation.
The annual site Hydrocarbon Audit was conducted and an action plan developed for
each area.
The main recommendations related to specific hydrocarbon management in some
areas within the surface Mine workshops and the underground mine fuel bay, including
provision of spills kits and improving storage areas and bunds to avoid and capture any
spillages. The main recommendation for Processing and Smelter was to improve
bunds in storage areas through correct use and provision of appropriate/additional
facilities. The standard of housekeeping could also be improved within each area with
emphasis on increasing ownership and education.
2.4.2 ID 2.6 Radioactive Process Material Spills
Targets FY11:
All spills of radioactive process material during the reporting period occurred within the
plant and TRS areas and did not result in harm to the environment or radiation risk to
personnel.

Concentrator – reduce recordable spills of radioactive process
material by 10% of the FY10 target (to less than or equal to 14 spills).
Recordable spills of radioactive process materials in the Concentrator were 21% above
target with 17 events recorded in FY11. Figure 2-11 shows the number of recordable
spills of radioactive process material in FY11.

Hydromet – maintain recordable spills of radioactive process material
at the FY10 target (to less than or equal to 18 spills).
Recordable spills of radioactive process materials in the Hydromet were 22% above
target with 22 events recorded. Figure 2-11 shows the number of recordable spills of
radioactive process material in FY11.

Smelter – reduce recordable spills of radioactive process material by
10% of the FY10 target (to less than or equal to 11 spills).
Recordable spills of radioactive process materials in the Smelter were 18% below

Refinery – maintain recordable spills of radioactive process material at
the FY10 target (to less than or equal to 6 spills).
Recordable spills of radioactive process materials in the Refinery were 67% below
Page 23

1 JULY 2009 – 30 JUNE 2010
Infrastructure – maintain recordable spills of radioactive process
material at the FY10 target (less than or equal to 4 spills).
Recordable spills of radioactive process materials within Infrastructure were above
45
40
Number of spill events
35
30
25
20
15
10
5
0
Concentrator
Hydromet
Smelter
FY07
FY08
Refinery
FY09
FY10
Mine
Infrastructure
FY11
Figure 2-11: Number of radioactive process material spill events recorded in
each area FY07 to FY11.

Mine – maintain recordable spills of radioactive process material at the
FY10 target (less than or equal to 5 spills).
Recordable spills of radioactive process materials at the Mine were below target with 3
events recorded. Figure 2-11 shows the number of recordable spills of radioactive
process material in FY11.
Action Plan FY11:

Continue with the annual Processing Environmental Improvement Plan
process.

Continue with the annual
Improvement Plan process.
Smelter
/
Refinery
Environmental

Continue with the annual Mining Environmental Improvement Plan
process.
Page 24
1 JULY 2010 - 30 JUNE 2011
An EIP for the mine was developed and implemented throughout FY11. Outstanding
actions will be considered in the FY12 EIP process.

Develop an annual Infrastructure Environmental Improvement Plan.
The FY11 Infrastructure EIP was developed during the reporting period with actions
entered and tracked within First Priority (FPe), an internal system for HSE
management.
2.5 ID 03 Generation of Wastes – Tailings Storage System (TRS)
2.5.1 ID 3.1 Embankment Stability
Targets FY11:

Review the slope stability around the perimeter of TSF Cells 1-4 using
actual measured pore pressure distributions and confirm the factors
of safety for embankment stability.
Geotechnical drilling and testing was undertaken around the perimeter of TSF Cells 1-3
during FY11. A review of the stability of TSF Cells 1-3 was undertaken using this
information, as well as actual pore pressure measurements.

Install a buttress and filter at the toe of the western embankment of
TSF Cell 3 and the adjacent eastern section of the northern
embankment of TSF Cell 4.
The buttress was installed during FY10 as planned. Refer to Section 10 – Waste for
more detail.
Action Plan FY11:

Prepare a report on the embankment stability of TSF Cells 1 to 4 using
actual pore pressure monitoring data.
A report was prepared on the stability of TSF Cells 1-3 during FY11 based on results
from geotechnical investigations.

Complete the detailed design and construction of a buttress and filter
at the toe of the western embankment of TSF Cell 3 and adjacent
eastern section of the northern embankment of TSF Cell 4.
The buttress was installed during FY10 as planned.

Install de-watering bore in spine of cells 3/4 to try to intercept liquor.
A de-watering bore was installed during the reporting period into the mullock spine
separating TSF Cell 3 and TSF Cell 4. This was successfully commissioned and has
reduced seepage reporting to the Cell 3/4 Buttress by over 95%. Refer to Section 10 –
Waste for more detail.
2.5.2 ID 3.2 Seepage
Targets FY11:

The groundwater level in the Andamooka Limestone aquifer outside the
perimeter of TSF Cells 1 to 4 shall not rise above 80 metres AHD.
The groundwater level in the Andamooka Limestone aquifer outside the perimeter of
TSF Cells 1-4 did not rise above 80m AHD during the reporting period. The maximum
level during FY11 was 67.26m AHD.
Page 25
1 JULY 2009 – 30 JUNE 2010
Action Plan FY11:

Identify and install additional liquor interception systems if required.
A liquor interception system is planned to be installed at Location 13A/B during FY12
as a precautionary measure. No other locations requiring liquor interception systems
were identified during FY11.
2.5.3 ID 3.3 Fauna Interaction
Targets FY11:

Initiate assessment of the potential for Sound ID as an on demand
deterrent system.
Completed, refer to comments under action plan FY11.

Initiate assessment of the durability of the HDPE balls and netting
within the TRS.
Completed, refer to comments under action plan FY11.
Action Plan FY11:

Continue trials of Sound ID acoustic recognition systems
Trials of sound identification software continued, to determine its efficacy at identifying
waterbird species and its potential use as part of an on demand deterrent system. At
this stage the SoundID system will be investigated, plans for the Marine Radar have
been put on hold pending the outcomes of the SoundID trial. Assessments suggest that
SoundID has the potential to be equally or more effective than a marine radar system.

Continue trials of HDPE netting and balls within the TRS
HDPE netting and balls remained in place and were monitored throughout the reporting
period. Trials are planned to continue to determine longer term durability of the
materials.
2.6 ID 03 Generation of Wastes – General and Industrial Waste
2.6.1 ID 3.4 Solid Waste (Non Hazardous and Hazardous)
Action Plan FY11:

Improve data availability and integrity for tracking of wastes from
source to disposal.
Several aspects of data availability and integrity were improved during FY11. The main
improvement was in the recording of waste disposed to landfill. Historically recyclable
material diverted from landfill wasn’t recorded, leading to an overestimation in waste
disposed to landfill. Data management has been improved so that these values can be
recorded and a more accurate figure calculated. Volumes of material reused around
site are also captured, leading to improved data availability and integrity.
Data availability has also been improved by the addition of a monthly summary for
major inputs and outputs from the Resource Recovery Centre. Percentages of material
to landfill, material recovered from landfill and material delivered to recycling point are
reported on monthly.

Set targets for waste recycling based on collected data.
Based on the improved data availability and integrity, targets have been set for FY12.
Page 26
1 JULY 2010 - 30 JUNE 2011
2.6.2 ID 3.5 Radioactive Waste
Targets FY11:

Maintain the area of liquor stored in the TRS below or equal to 22ha as
a monthly average.
The area of liquor stored in the TRS averaged 45.1ha over the reporting period with a
June 2011 value of 53.5ha (Figure 2-12). Liquor area remained over target during the
year due to ongoing issues with above average rainfall of 278mm, low tailings densities
and reduced evaporation pond capacity.
60
50
Hectares
40
30
20
10
Target
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
Actual
Figure 2-12: Area of liquor stored on TSF Cells 1 – 4 during FY11
Action Plan FY11:

Continue to develop, update and implement a strategy towards
minimising radioactive waste produced from the mining and
processing of ore.
Whilst no strategy document has been produced, current work on reducing radioactive
waste is around disposal of redundant contaminated plant items. Minimisation of ore
tailings material is generally limited to improvements in processing recoveries and
efficiencies (i.e. reducing water and reagent input to limit overall volume of tails
produced) and use of tailings sands as mine backfill material.
A project is underway to replace the defective uranium solvent extraction crud
centrifuge. Without the centrifuge operating waste volume is greater as process liquids
are entrained in the crud. The centrifuge separates the crud into solids, aqueous liquor
and organic solvent. This allows for the aqueous and organic to be recycled reducing
water and solvent input and minimising the volume of material sent to the TSF.
There are a number of demolition projects scheduled for the upcoming financial year to
remove redundant plant. The Environment and Radiation section are assisting project
planners assess the radioactive contamination levels in order to minimise the volume of
material that will be classified as radioactive waste. Projects currently scheduled
include the pilot plant and the pregnant leach solution sand filters. Scoping projects
may also commence for demolition of smelter 1 and the old extraction plant.
Investigation has also commenced on alternative storage options for redundant
contaminated plant classified as low level radioactive waste (LLRW). LLRW is currently
Page 27
1 JULY 2009 – 30 JUNE 2010
disposed into the TSF and there is a quantity stored at the Resource Recovery Centre.
The investigation will look at the feasibility of alternative sites which may be able to be
made into compliant storage facilities, e.g. the old mine water disposal pond and the
quarry.
2.7 Conclusion
FY11 saw 75% of our targets and actions achieved; an increase of 6% from the
previous reporting period. Significant progress was made on 9% of our actions and
targets whilst 16% were not met.
Targets met include:


Reducing flow of water from pastoral bores by 4ML/d from the FY08 baseline;
Maintaining and industrial water efficiency of 1.12kL/t at an annual production rate
of 10Mt;
 Updating the existing hydrogeological model to include additional spring groups
and information from new monitoring bores;
 Reviewing our Environment and Indigenous Heritage Clearance Permit procedure
to include the Native Vegetation Management Plan and Significant Environmental
Benefit requirements;
 Updating the Closure and Rehabilitation Plan;
 Rehabilitation of TSF5 construction support areas;
 The groundwater level in the Andamooka Limestone aquifer outside the perimeter
of TSF Cells 1-4 did not rise above 80m AHD during the reporting period. The
maximum level during FY11 was 67.26m AHD;
 Significant improvements in streamlining data collection of measurements of
energy and greenhouse gas emission data;
 Remediation of saline contamination areas around RB21; and,
 Installation of a buttress and filter on the northwest corner of TSF Cell 3.
Targets not met included:





Three targets relating to the reduction of SO2 emissions;
Four targets relating to the number of spills of chemicals and hydrocarbons;
Three targets relating to the number of spills of radioactive process material; and,
One target relating to area of liquor stored on the TSF due to above average rainfall
and reduced capacity of evaporation ponds contributing to increased area of liquor
on TSF;
Continuation of trials of the SoundID acoustic recognition system for potential use
as an on-demand deterrent at the TRS
Page 28
1 JULY 2010 - 30 JUNE 2011
Figure 2-13: Olympic Dam site layout
Page 29
1 JULY 2010 - 30 JUNE 2011
3 GROUNDWATER MONITORING PROGRAM
3.1 Groundwater Abstraction and Mine Water Balance
3.1.1 Background
Olympic Dam abstracts groundwater from both aquifer systems within the Special
Mining Lease. The shallow Andamooka Limestone is completely dewatered in the mine
area with inflows into the mine only from the deeper quartzite aquifer. In the TSF area
and around the process plant there is considerable saturated thickness in the limestone
due to seepage induced mounding. Local groundwater is used primarily for dust
suppression, construction work, underground mining operations and in the Backfill
Plant. Water supply facilities include:

Saline Wellfield, comprising several bores which intersect the Arcoona
Quartzite aquifer (Figure 3-2);

Production bore LP02, located on the north side of the TSF producing from the
TSF seepage mound in the Andamooka Limestone aquifer (Figure 3-2).
3.1.2 Purpose



Monitor abstraction rates from the TSF mound and saltwater wellfield and analyse
patterns of saltwater use.
Maintain an understanding of the mine water balance through measurement,
derivation or estimation of key parameters.
Estimate groundwater discharge to the mine workings.
3.1.3 Deliverable(s)



Review abstraction rates and trends and assess with respect to groundwater levels.
Define and map the mine water balance.
Estimate the degree of groundwater discharge to the mine.
3.1.4 Method
Average daily production from production bore LP02 and the saltwater wellfield is
monitored and recorded as the monthly average abstraction in ML/d.
The mine water balance is calculated annually from a combination of measured,
derived and estimated data.
GROUNDWATER MONITORING PROGRAM
Page 31
Figure 3-1:
Page 32
1 JULY 2010 - 30 JUNE 2011
Olympic Dam regional bore locations
1 JULY 2010 - 30 JUNE 2011
Figure 3-2:
Olympic Dam site area bore locations
Page 33
1 JULY 2010 - 30 JUNE 2011
Figure 3-3:
Simplified Olympic Dam hydrogeological cross-section
3.1.5 Results/Discussion
LP02 – TSF Mound
Abstraction from the Andamooka Limestone aquifer using production bore LP02
averaged 0.14ML/d (Figure 3-4) from July 2010 to June 2011, compared to 0.17ML/d
over the previous reporting period.
In previous reporting periods, water from LP02 has not been included in the mine water
balance. However, this water source has been integrated with the surface and mine
saline water network, and can no longer be considered a separate water source.
Saline Wellfield
Saline water was abstracted from the Arcoona Quartzite throughout FY11 from the
Saline Wellfield, located south of the Whenen Shaft.
Some of this water from the Saline Wellfield was used in construction projects
throughout the operations, whilst the remainder was discharged to the mine water
disposal pond for evaporation. An average of 2.59ML/d was abstracted over the period,
compared to 1.33ML/d during the previous reporting period.
Page 35
4.0
3.5
Water abstraction (ML/d)
3.0
2.5
2.0
1.5
1.0
0.5
TSF (LP02) Supply
Figure 3-4:
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0.0
Saline Wellfield
Site groundwater abstraction
Groundwater Discharge to the Mine
Groundwater inflow to the mine occurs at several intersections with the underground
operations. Total natural inflow is estimated to be approximately 3.00ML/d, the majority
entering via upcast raise bores. Additional natural inflow comes into the mine via other
entry points, including downcast raise bores, exploration drill holes and shafts (Figure
3-5). The majority of the total inflow to the mine is exhausted to the surface as saline
aerosols or moisture-laden air via upcast raise bores, estimated at around 2.50ML/d.
Mine Water Balance
The mine water balance is a summary of the volume of water going into and out of the
underground mine. It includes saline water abstracted from local bores that is added to
surface storages and used around site. The balance presented in Figure 3-5 is
generated from a combination of measured, derived and estimated data.
Page 36
1 JULY 2010 - 30 JUNE 2011
FY11 Yr Mine Water Balance Summary (ML/d)
0.8
1.1
Disposal/Losses
Evaporation/Misc Losses
Mine Water Disposal Pond
Supply Sources
0.0 Misc Supply
0.0 Surface Recycled Potable
2.6 Saline Borefield
0.1 Andamooka Limestone Aquifer
Surface
1.9
2.7
.
1.6
Construction Use
Total Use Underground
4.3 Saline Droppers
0.8 CAF Bleed
5.1
5.9
Natural Inflow
3.0
Underground Recycled
Potable
0.3
Dewatering Risers
1.6
0.9
Underground
Raisebore Aerosols
Ore Moisture
2.5
Estimated
Calculated or derived with some assumptions applied
Measured value

Note: sum of individual items may not exactly match totals due to rounding.
Figure 3-5:
Mine water balance summary FY11 (ML/d)
3.2 Groundwater Levels
3.2.1 Background
Mine dewatering and seepage from surface facilities has resulted in altered
groundwater levels in both the Andamooka Limestone and Arcoona Quartzite aquifers.
Standing water levels differ between the aquifers from between 1m and 15m, with the
potentiometric surface being approximately 50m below the surface when unaffected by
Olympic Dam’s activities.
In the centre of the mine area, groundwater is constantly being depleted in both
aquifers creating a cone of depression which extends for a distance of approximately
5km in the Arcoona Quartzite aquifer and approximately the same distance to the
north, south and east in the Andamooka Limestone aquifer.
To the west, seepage from the TSF and old mine water pond area have created a
groundwater mound which has risen to a maximum height of approximately 30m below
the ground surface. The low transmissivity in the limestone aquifer, limited
hydrogeological interconnection to the Arcoona Quartzite aquifer and the limited
number of man-made interconnections (exploration drill holes, ventilation shafts etc.)
result in the mound changing very little over extended periods of time, i.e. years.
Abstraction from production bore LP02 from January 2000 has reduced the
groundwater mound. Commissioning approval for TSF Cell 4 requires BHP Billiton
Olympic Dam to ensure that ground water levels do not rise above 80mAHD. A
contingency plan nominates remedial action that can be undertaken.
The groundwater has no natural surface expression in the vicinity of the Olympic Dam
Mine, and is at sufficient depth as to not adversely affect the native vegetation.
3.2.2 Purpose


Define the extent of groundwater level changes that have resulted from Olympic
Dam’s activities.
Maintain groundwater levels in the tailings retention area to below a level at which
native vegetation could be affected.
Page 37
3.2.3 Action Trigger
A trending increase in the groundwater level that indicates that 80mAHD may be
exceeded within 12 months.
3.2.4 Method
Groundwater levels are monitored utilising a network of exploration and groundwater
monitoring bores in both the Andamooka Limestone and Arcoona Quartzite aquifers.
If for some reason a groundwater level cannot be obtained (e.g. blocked bore), the
nearest suitable bore will be located and monitored if appropriate. Olympic Dam will
maintain sufficient monitoring bores to satisfy the requirements of the ground water
model and approval MPNR98/0034 Reg 98/2639 98/2885, 6/1/99, Condition 3.
Andamooka Limestone Aquifer Groundwater Levels
Water levels in the limestone aquifer beneath the TSF (Figure 3-6) remain stable. The
extent of the area with a groundwater level above 65mAHD reduced slightly from
previous years. The drawdown cone on the north side of the TSF corresponding to
LP02 has reduced further as a result of reduced pumping volumes from this bore (see
Section 3.1.5). Groundwater levels beneath the TSF between June 2010 and June
2011 confirm these changes (Figure 3-7 and Figure 3-8). Water levels have decreased
around the Quarry, where inflow into the A North Decline has resulted in localised
drawdown. The maximum groundwater level recorded below the TSF for the current
reporting period was 67.26mAHD at LT50 in March 2011, 0.52m higher than the
maximum during the FY10 reporting period. However this measurement is
uncharacteristic of the general trend of falling water levels at LT50. Trends indicate that
water levels are not expected to exceed the agreed limit (TSF Cell 4) of 20m below the
ground (80mAHD) within the next 12 months.
Monitoring of bore LM25, located near the Olympic Dam Desalination Plant,
commenced in June 2005 and following a gradual decline has remained stable over
recent years. Monitoring bore LR07, located in the Roxby Downs Township, continues
to report stable groundwater levels. A slight level increase is evident at LR03, near the
town water storage dams. Trends at this bore will be monitored.
Water levels at LM46 (Figure 3-9), located near the mine water disposal pond to the
northeast of the mine area, finished the reporting period at 61.77mAHD. This is an
increase from 60.64mAHD last year. Water levels increased rapidly from September
2008, due to the increase in water volume discharged into the pond from the trial mine
dewatering project. Water level has been relatively stable since but recent increases in
discharge appear to be resulting in a gradual water level rise. Nearby LM43 has shown
near identical water level changes.
Page 38
1 JULY 2010 - 30 JUNE 2011
June 2006
June 2010
Groundwater level (mAHD)
June 2011
70
65
60
55
50
35
Datum: GDA94
Projection: MGA94
Zone: 53
Figure 3-6:
TSF area groundwater levels (mAHD) - Andamooka Limestone
aquifer
Page 39
75
Groundwater level (m AHD)
70
65
60
55
45
-4000 West
-3000
-2000
-1000
0
1000
LT18
LT17
LT16
LT09
LT51
LT50
LT45
LT52
LT35
LT19
50
2000 East
Distance from centre of tailings (m from LT05)
Jun-06
Jun-10
Jun-11
Note

Monitoring bore locations shown in Figure 3-2
Figure 3-7:
Change in groundwater elevation along an east-west cross-section
from LT19 to LT18, through the centre of the TSF
75
LT06 replaced by LT45
70
65
60
55
50
LT05
LT06
LT07
LT16
LT18
LT19
LT36
LT45
LT50
LT51
Jun-11
Dec-10
Jun-10
Dec-09
Jun-09
Dec-08
Jun-08
Dec-07
Jun-07
Dec-06
Jun-06
Dec-05
Jun-05
Dec-04
Jun-04
Dec-03
Jun-03
Dec-02
Jun-02
Dec-01
Jun-01
45
LT52
Note

Figure 3-8:
Page 40
Groundwater levels for Andamooka Limestone bores in the vicinity
of the TSF
1 JULY 2010 - 30 JUNE 2011
75
70
Town storage liner replaced
65
60
55
50
LR03
LR07
LM25
LM43
Jun-11
Dec-10
Jun-10
Dec-09
Jun-09
Dec-08
Jun-08
Dec-07
Jun-07
Dec-06
Jun-06
Dec-05
Jun-05
Dec-04
Jun-04
Dec-03
Jun-03
Dec-02
Jun-02
Dec-01
Jun-01
45
LM46
Note

Monitoring bore locations shown in Figure 3-1 and Figure 3-2
Figure 3-9:
Groundwater levels for Andamooka Limestone bores in the vicinity
of Roxby Downs (LR) and the Mine Water Pond (LM)
Arcoona Quartzite Aquifer Groundwater Levels
An aquifer drawdown pattern is apparent in the Arcoona Quartzite due to the
dewatering around the mine workings. Over previous years the gradual drawdown
trend that has remained more or less constant (Figure 3-10 and Figure 3-11). During
the reporting period levels have continued to drop although bores closer to the current
mine workings (RD115) remain stable.
RD364 was destroyed as a result of mining activities during FY06 and removed from
the monitoring program. RD169, located west of RD364, exhibits a similar drawdown
curve and has been shown in Figure 3-10 as a replacement, with RD364 left for
comparison. RD479 was destroyed in FY09 as a result of mining activities. During the
reporting period a reading was not able to be determined for RD194 due to bore
integrity. RD66, located west of RD194, has been shown here as a replacement. Water
level at RD115 remains stable due to its proximity to the mine and consistent
drawdown patterns in that area.
Page 41
60
40
20
0
-20
-40
-60
RD66
RD115
RD169
RD172
RD194
RD364
Jun-11
Jun-10
Jun-09
Jun-08
Jun-07
Jun-06
Jun-05
Jun-04
Jun-03
Jun-02
Jun-01
Jun-00
Jun-99
Jun-98
Jun-97
Jun-96
Jun-95
Jun-94
Jun-93
Jun-92
Jun-91
Jun-90
-80
RD479
Note

Figure 3-10: Groundwater levels for exploration drill holes in the vicinity of the
underground mine
Page 42
1 JULY 2010 - 30 JUNE 2011
June 2006
June 2010
Groundwater level (mAHD)
June 2011
60
40
20
0
-20
-40
-60
-80
Datum: GDA94
Projection: MGA94
Zone: 53
Figure 3-11: Mine area groundwater levels (mAHD) - Arcoona Quartzite aquifer
Page 43
3.3 Groundwater Quality
3.3.1 Background
Groundwater in the vicinity of the operation contains water of poor quality and, as
defined by ANZECC (2000), is not suitable for supporting the environmental value
categories (aquatic ecosystems; recreation and aesthetics; drinking supply; primary
industry). Local groundwater is also unsuitable for ore processing at Olympic Dam.
3.3.2 Purpose

Monitor groundwater quality in the vicinity of the operations.

Quantify any possible impacts of seepage.
Review trends and make comparisons to ANZECC criteria.
3.3.4 Method
Aquifer specific monitoring bores are pumped or bailed in order to obtain a
representative groundwater sample for quality analysis. The samples are analysed for
the following analytes:

TDS, pH, calcium, chloride, copper, iron, manganese, sulphate and uranium.

In addition, samples will be analysed for the following radionuclides:

238
U, 226Ra, 230Th, 210Pb and 210Po
If for some reason a groundwater sample cannot be obtained (e.g. blocked bore), the
nearest suitable bore will be located and sampled if appropriate.
Groundwater samples were collected and subsequent analytical chemistry data was
obtained for 17 groundwater monitoring bore locations in May 2011. Groundwater
summary data is shown in Table 3-1. Monitoring bores sampled in May 2011 varied
slightly from those detailed in BHP Billiton Olympic Dam (2010c) due to access
restrictions or loss/abandonment of bores. These variations are summarised below:

Bore LR6 was sampled instead of LR7 due to issues with high silt levels;

Bore LT21 was sampled instead of LT29 to provide a more even spacing in
sampling locations;

Bore LT25 was included in the 2011 sampling event and is located in close
proximity to the southwest corner of Evaporation Pond 2;

Bore LT26 was abandoned and backfilled during the Evaporation Pond 1 wall
raise;

Bore LT51 was not sampled as the PVC casing in the bore has been damaged
likely by construction activities in the area; and,

Bore LT61 was sampled instead of LT60 due to assess restrictions.
In the majority of bores, the salinity has remained relatively stable and within the range
that could be expected for natural variation within the aquifer. The exceptions were
bore LT17, which has risen from 34,000mg/L in the previous reporting period to
54,000mg/L; and, bore LM46 which has fallen from 65,000mg/L to 49,000mg/L in the
current reporting period.
In the majority of bores, uranium concentrations have remained relatively stable since
the previous reporting period. The highest uranium concentration in the 2011
monitoring event was from bore LM46, located adjacent to the mine water pond,
Page 44
1 JULY 2010 - 30 JUNE 2011
northeast of the mine (0.53mg/L), and is slightly higher than when sampled in 2010
(0.37mg/L). The uranium concentration recorded in 2011 remains less than that
recorded in 2009 (0.71mg/L).
Uranium concentrations of 0.48mg/L were recorded from bore LT25 in 2011. This bore
is located at the southwest corner of Evaporation Pond 2. Bore LT25 was sampled for
the first time in 2011 and will be included in future monitoring to confirm the elevated
uranium concentration. The reported uranium concentrations in 2011 are lower than
the adopted ANZECC (2000) guidelines for livestock consumption of 0.2 mg/L except
at LM46 (0.53mg/L), LT25 (0.48mg/L and LT15 (0.48mg/L). The depth (approximately
40m – 50m below ground level) and the high salinity (>19,000mg/L TDS) of the local
groundwater will restrict the likelihood that it would be consumed in any significant
quantities, thus not posing a health hazard to people or fauna.
The groundwater monitoring program continues to define the impacts of seepage in a
clear and repeatable manner. The soil cover and underlying limestone rock mass
continues to effectively attenuate elements present in seepage from the TSF.
All analytical results are shown in Table 3-1 below.
Table 3-1:
Groundwater chemistry data for bores located in the vicinity of
Olympic Dam
pH
Cu
U
Mn
Chloride
SO4
Ca
Fe
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
2.00
0.02
0.50
N/A
500
N/A
N/A
N/A
N/A
0.50
0.20
N/A
N/A
1000
N/A
N/A
N/A
5000
LM43
May 2011 <0.005
0.063
1.1
21000
2000
1300
1.6
6.9
39000
LM46
May 2011 <0.005
0.532
<0.025
28000
2100
1300
<0.25
7.3
49000
LR6
May 2011 <0.005
0.016
2.0
12000
1500
980
0.60
7.2
26000
LR8
May 2011 <0.005
0.020
0.47
15000
1500
1100
1.8
7.4
31000
LR9
May 2011 <0.005
0.031
2.3
14000
1900
1100
4.6
6.8
28000
LT1
May 2011 <0.005
0.106
0.58
12000
1600
880
2.2
6.9
24000
LT2
May 2011 <0.005
0.047
1.5
12000
1600
1000
7.5
6.5
26000
LT15
May 2011 <0.005
0.479
<0.025
11000
1900
1100
<0.25
6.8
34000
LT17
May 2011
0.009
0.069
<0.025
23000
1900
1300
<0.25
7.6
37000
LT19
May 2011 <0.005
0.025
0.54
11000
1600
960
1.2
7.2
24000
LT21
May 2011 <0.005
0.138
0.31
12000
1800
950
0.07
6.8
26000
LT22
May 2011 <0.005
0.072
<0.025
4500
1500
730
<0.25
7.4
19000
LT25
May 2011 <0.005
0.484
7.9
12000
2200
850
34
6.4
27000
LT34
May 2011 <0.005
0.045
0.72
13000
1900
980
1.6
6.9
26000
LT35
May 2011 <0.005
0.046
0.75
11000
1800
990
2.0
6.8
24000
LT39
May 2011 <0.005
0.033
0.86
14000
1700
1000
3.0
7.1
26000
LT61
May 2011 <0.005
0.017
0.53
13000
1700
1000
2.3
7.2
27000
Analyte
Drinking Limit
(ADWG 2004)
Livestock (Sheep)
Limit
TDS
(mg/L)
(ANZECC, 2000)
Bore
Date
Page 45
3.4 Use of Mine Water for Dust Suppression
3.4.1 Background
Water obtained from the mine as a result of mine dewatering or collected from vent fan
outflow is used around site for watering of roads for the purpose of dust suppression.
Local groundwater is of very low quality and is unsuitable for other industrial or
environmental uses. Radiation levels in mine water used for road watering are
monitored annually to ensure they remain within acceptable levels.
Table 3-2:
Upper limits for radionuclide content in dust suppression water
Radionuclide
238
Upper Limit Value
(Bq/L)
U
50
Ra
5
226
3.4.2 Purpose
Monitor sources of mine water used for road watering.
Ensure negligible long term effects of the release of mine water.


Ensure water used for dust suppression is within acceptable radiation levels as
defined in Table 3-2.
Review results and provide for increased monitoring frequency where readings
approach the action trigger level.


A radiation level obtained from sampled mine water that approaches the upper
limits of the acceptable radiation level.
A trend indicating that the radiation level upper limit will be exceeded within a
period of 12 months.
3.4.5 Method
Sources of mine water, including raise bore ponds and storage dams, are sampled at
least once per year and checked for radiation levels. Where readings for a source are
near to or above the action trigger, additional monitoring will be conducted on a more
frequent basis. Use of mine water from a source found to exceed the limit will cease
until the radiation level has been found to have dropped below that limit.
Samples from water used for dust suppression were collected during May 2011 and
results are shown in Table 3-3, Figure 3-12 and Figure 3-13.
238
U and 226Ra activity levels for all samples were well below the respective upper limits
and are consistent with previously recorded values.
Page 46
1 JULY 2010 - 30 JUNE 2011
Table 3-3:
Radionuclide analysis for dust suppression water
238
Radionuclide
230
U
Th
(Bq/L)
(Bq/L)
226
Ra
(Bq/L)
210
Pb
(Bq/L)
210
Po
(Bq/L)
Sample ID
Date
DESAL PLANT
May 2011
0.08
0.010
2.10
0.002
0.008
A-BLOCK
May 2011
0.63
0.120
2.20
0.000
0.021
D-BLOCK
May 2011
10.70
0.060
1.00
0.122
0.110
F-BLOCK
May 2011
15.70
0.013
1.10
0.007
0.017
TURKEY NEST
May 2011
0.82
0.000
0.59
0.000
0.000
50
Upper limit
30
Activity level
238
U (Bq/L)
40
20
10
0
Desal Dam
A Block
D Block
F Block
Sample site
Figure 3-12: Mine water sample 238U levels and upper limit, FY11
Page 47
5.0
Upper limit
3.0
Activity level
226
Ra (Bq/L)
4.0
2.0
1.0
0.0
Desal Dam
A Block
D Block
F Block
Sample site
Figure 3-13: Mine water sample 226Ra levels and upper limit, FY11
3.5 Conclusion





Average abstraction rates from the TSF mound (LP02) and Saline Wellfield were
0.14ML/d and 2.59ML/d respectively.
Peak groundwater level beneath the TSF for this reporting period was
approximately 67mAHD. Levels are not expected to exceed the limit of 80mAHD
(20m below the ground) within the next 12 months.
The drawdown cone in the Arcoona Quartzite aquifer has changed slightly although
water level in bores closer to the current mine workings remain stable.
Slightly elevated concentrations of uranium continue to be detected in the
groundwater beneath the mine water disposal pond and old mine water disposal
pond. Measured values do not pose a health hazard due to the low concentrations
and the salinity of the water, which restrict its use for human or animal
consumption.
Radiation activity levels for dust suppression water were found to be consistent with
those measured in FY10 and were all below the upper limit values.
Page 48
1 JULY 2010 - 30 JUNE 2011
4 GREAT ARTESIAN BASIN (GAB) WATER
MONITORING PROGRAM
Water used at Olympic Dam and the Roxby Downs township is pumped from two
wellfields located within the GAB. A summary and interpretation of data related to the
impact of Olympic Dam on the GAB is the subject of a separate annual GAB Wellfields
Report (BHP Billiton Olympic Dam 2011a), produced in accordance with the
requirements of the Roxby Downs (Indenture Ratification) Act 1982. The Wellfields
Report 1 July 2010 – 30 June 2011 is attached to this document and the content is not
repeated in this section. The requirements of Olympic Dam in regard to management of
GAB groundwater supply issues are outlined in the Monitoring Program – Great
Artesian Basin (GAB) FY11 (BHP Billiton Olympic Dam 2010d).
GREAT ARTESIAN BASIN (GAB) WATER MONITORING PROGRAM
Page 49
5 FAUNA MONITORING PROGRAM
5.1 Avifauna
5.1.1 Background
Previous monitoring and research has indicated that several species or species groups
of birds may be used as indicators of impacts associated with the mine and processing
operation. It has been demonstrated that Crested Bellbirds and mixed feeding flocks of
insectivorous birds decrease in abundance in close proximity to the operation (Read et
al. 2000, Read et al. 2005). Past research has also determined a group of bird species
that have been seen to benefit from the presence of operations, known as ‘disturbance’
species. The presence/absence of these bioindicators and species richness of ‘nondisturbance’ bird species at different site types are surveyed.
5.1.2 Purpose
Utilise avifauna as an indicator of environmental change.
Map the impact footprint of Olympic Dam’s activities on abundance of Crested Bellbirds
and mixed feeding flocks of insectivorous birds, and species richness of ‘nondisturbance’ species, for the Environmental Management and Monitoring Report.
5.1.4 Method
A total of 48 sites are surveyed in April, July and October for all bird species present.
Sites are separated into three main areas defined by potential impact: mine (within
500m of mine and process); intermediate (1km from mine and process); and control (>
4km from mine and process) (Figure 8-1). Each site is located on a dune containing a
patch of mulga woodland and other shrub species. Each site covers an area 200m by
200m.
During each survey period all sites are surveyed for a period of 10 minutes. During this
time all birds, seen and heard, are recorded. Surveys are conducted in the morning,
within four hours of sunrise, allowing approximately six sites to be surveyed each day.
Avifauna survey data are used to determine the presence/absence of bioindicator
species and the species richness of ‘non-disturbance’ bird species at different site
types.
The overall abundance of Crested Bellbirds and mixed feeding flocks within mine,
intermediate and control zones remained similar to previous years (Figure 5-1 and
Figure 5-2). There was a significant difference in abundance of Crested Bellbirds
recorded at mine, intermediate and control sites (Kruskal-Wallis non-parametric test, 2
= 20.34 and P = <0.001). Numbers of Crested Bellbirds were higher at intermediate
sites than mine sites and higher at control sites than intermediate sites (Figure 5-1).
This trend is consistent with previous reporting periods.
No significant difference was detected between abundances of insectivorous mixed
feeding flocks at sites distant from the operations and those within the immediate
vicinity of the operations (Kruskal-Wallis non-parametric test, 2 = 4.01 and P = 0.135),
however graphically the trend shows a lower number closer to operations (Figure 5-2).
Page 50
FAUNA MONITORING PROGRAM
1 JULY 2010 - 30 JUNE 2011
3.5
Mean number of CBB (+SE)
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Mine (n=15)
FY00
Figure 5-1:
FY01
Intermediate (n=17)
FY02
FY03
FY04
FY05
FY06
Control (n=17)
FY07
FY08
FY09
FY10
FY11
Abundance of Crested Bellbirds (CBB) in each of the monitoring
zones (± 1 standard error).
8.0
7.0
Mean number of IFF (+SE)
6.0
5.0
4.0
3.0
2.0
1.0
0.0
Mine (n=15)
FY00
Figure 5-2:
FY01
Intermediate (n=17)
FY02
FY03
FY04
FY05
FY06
Control (n=17)
FY07
FY08
FY09
FY10
FY11
Abundance of insectivorous feeding flock (IFF) species in each of
the monitoring zones (± 1 standard error).
An impact footprint of the bioindicators, Crested Bellbirds (CBB), insectivorous feeding
flocks (IFF) and the species richness of ‘non-disturbance’ bird species, suggests that
the impacts of the operations on avifauna are limited to the immediate vicinity of the
mine and processing plant and surrounding areas within the Special Mining Lease
(Figure 5-3). The impact footprint for the current reporting period appears slightly larger
than the FY10 mapped impact footprint (Figure 5-3).
Page 51
Figure 5-3:
Impact footprint of the bioindicator bird species during FY10 and
FY11 periods
5.2 Small Mammals and Reptiles
5.2.1 Background
Small mammals and reptiles are used as biological indicators of the condition of the
environment, both adjacent to, and at a distance from, the mine and processing plant.
These studies allow examination of the nature and extent of impacts.
Geckos, due to their sensitivity to air pollution, are the most suitable local reptiles for
use as bioindicators (Read 1998). Geckos have large eyes and soft skin, making them
susceptible to contaminants. Geckos are also ideal bioindicators as their fecundity is
readily measured, therefore any declines in fecundity as a result of operational
activities can be assessed.
Ctenotus skink captures generally exceed Ctenophorus dragon captures in unimpacted
sites (Read et al. 2005). Similarly, native rodent captures (Pseudomys sp., Leggadina
forresti, and Notomys alexis) generally exceed captures of House Mice (Mus
domesticus) in unimpacted sites (Read et al. 2005).
5.2.2 Purpose
Utilise small mammals and reptiles as an indicator of environmental change.
Map the impact footprint of Olympic Dam’s activities on the fecundity of geckos,
Ctenotus/Ctenophorus ratios and feral/native mouse ratios for the Environmental
Management and Monitoring Report.
5.2.4 Method
Reptile abundance, mammal abundance, and abundance, age, and fecundity of
geckos are recorded annually during a trapping session each December. A total of 14
sites are monitored with sites located in areas as defined by possible impacts. These
include sites located near the smelter and ventilation shafts, and also intermediate and
Page 52
1 JULY 2010 - 30 JUNE 2011
control sites. The regional locations of the fauna monitoring sites are shown in Figure
8-2.
Animals are captured using pitfall traps. Each trapping site consists of 13 pitfall traps
arranged in a cross formation. The pits are five metres apart and, when opened, are
linked by a fly mesh fence. Between the annual sampling periods the fence is removed
and pits are left in place covered with tightly fitting caps.
The FY11 results showed an increased impact footprint compared with the FY10 period
(Figure 5-4). Sites closest to the operation generally scored lower than those at
distance, which may indicate evidence of impacts from mining and processing
operations. However scores for FY11 were biased by the high number of introduced
house mice in the region following good conditions brought on by an extended period
of above average rainfall. This may explain the expanded impact footprint during FY11.
Gecko fecundity scores were variable, although sites within the raisebore saline
exhaust area all scored 0%. While fecundity at sites near the smelter were higher, very
few geckos were captured there. Captures at intermediate and control sites were
generally higher. Results suggest some impact from the operation may be present.
Figure 5-4:
Impact footprint of reptiles and small mammals during FY10 and
FY11 periods
5.3 Amphibians
5.3.1 Background
The Trilling Frog (Neobatrachus centralis) is a medium sized burrowing frog that is
common in the Olympic Dam region. Typically large numbers of this species emerge
en masse following rainfall events of greater than 50mm during the warmer months.
Levels of limb abnormalities in frogs are investigated from individuals captured close to
the mine and metallurgical plant and at control sites distant from Olympic Dam.
5.3.2 Purpose
Utilise amphibians as indicators of environmental change.
Page 53
Establish if there is a difference in the incidence of abnormality in the most recent
cohort of Trilling Frogs in areas close to, and distant from, operations.
5.3.4 Method
Adult frogs are opportunistically sampled from sites close to (within 1km), and distant
from (over 4km), the mine and processing plant. Frogs are collected from the road, or
from areas surrounding and within bodies of water immediately following significant
rainfall. Snout-vent length and sex is determined and recorded for all frogs captured.
Juvenile frog offspring resulting from the breeding event triggered by significant rainfall
are collected over following weeks as they emerge from ephemeral water bodies. Each
frog is also carefully scrutinised for deformities before being released. Detailed
methods are described in Read and Tyler (1990).
As reported in the FY10 EMMR, on the 9th of April 2010 over 80mm of rain was
received. Following the rainfall frogs emerged, however the moderate temperatures
during that period meant that the frogs did not emerge en masse. As a result of this,
ideal sample sizes of frogs were not able to be collected.
Adult frogs were collected directly following the rainfall event, with 100 being collected
from close proximity to the operation and 212 collected distant to the operation.
Several weeks after the rain 440 metamorphlings were collected close to the operation
and 192 were collected away from the operation.
Abnormalities were detected in both adult frogs and metamorphlings. Further testing is
required to determine if abnormalities were due to mutations or injury. This is a highly
specialised skill and there has been some difficulty contracting a suitably skilled person
to complete the work. Frogs with abnormalities are currently being examined and
results will be available in FY12.
5.4 Feral and Abundant Species
5.4.1 Background
Kangaroos are native and commonly recorded medium sized mammals of the region,
however due to artificial water bodies and the lack of domestic grazing on the SML
their abundance is often altered. Both kangaroo and rabbit numbers directly affect the
condition of the vegetation on the mine and municipal leases. These herbivores also
affect the success of rehabilitation measures and amenity plantings within the mine and
municipal leases. Similarly, cat and fox numbers have the potential to increase in
response to land management practices and impact on native vertebrate populations.
Therefore, these medium sized mammal species can potentially have an impact on the
ecology of the region. For this reason medium sized mammal numbers are monitored
regularly and controlled when necessary.
5.4.2 Purpose
Monitor and control feral and abundant species within the Special Mining and Municipal
Leases.

Provide a quantitative assessment of the abundance of specific feral and abundant
species in the operations area.

Identify if measures are required to control feral or abundant species in the
operations area.
Page 54
1 JULY 2010 - 30 JUNE 2011
5.4.4 Method
The abundance of kangaroos, rabbits, cats and foxes is determined every three
months along three spotlight transects of approximately 20km in length (Figure 8-3).
Fixed transects are located in the dune country north of the operation, south of the
operation around the town lease boundary, and east of the operation on Andamooka
Station. All transects are located inside the dog fence. Cattle grazing occurs on
Andamooka Station but on all other transects cattle have been removed for over 15
years. Kangaroo harvesting is undertaken on Andamooka Station. A permanent water
source is available on the north transect while water is available irregularly in other
transects. The south transect is located among closely spaced dunes, while the other
two transects are located in an area of widely spaced dunes. As a result of the varying
transect characteristics, the number of kangaroos in the north transect are often
observed to be at levels significantly higher than those recorded in the other transects.
Cat and fox control is conducted in and around the operations and on the more remote
areas of the SML on an opportunistic basis, through trapping and baiting. Stomach
content analysis is conducted and reported for all cats and foxes collected.
Populations of feral and abundant mammals (rabbits and kangaroos) are largely
dependent on climatic conditions and fluctuate accordingly. Furthermore, these
populations are largely independent of mining and processing operations. Control of
these groups is also considered impractical on a large scale. House mice are not
controlled. As the operation is located in a pastoral area, they are not considered to be
a significant pest species.
Summaries of monitoring results for rabbits, kangaroos, foxes and cats are shown in
Table 5-1.
As expected, following the above average rainfall during FY10 and FY11, local rabbit
populations have risen over the monitoring period, more than doubling along some
transects (Figure 5-5). However, rabbit densities for the FY11 reporting period
remained lower than the long-term mean on all transects.
The number of cats observed during FY11 was also above FY10 records. On the mine
transect, the average abundance of cats observed during FY11 is above the long term
mean. Other transects remain below the long term mean (Figure 5-6). The higher
number of cats is likely a result of an increase in food availability (small mammals and
reptiles) following the above average rainfall during previous years. No foxes were
observed during FY11 monitoring (Figure 5-7).
The average abundance of kangaroos was lower than that recorded during FY10 on all
transects (Figure 5-8). The same trend was noticed when compared to the long term
mean. This is likely due to the dispersal of kangaroos given the favourable conditions.
Page 55
Table 5-1:
Summary of rabbit, cat, fox and kangaroo numbers (per square
kilometre), showing historical abundance, FY10 and FY11
Long-term
min
Long-term
max
Long-term
mean
FY10
mean
FY11
mean
Town
0
220
49.76
22.26
43.11
Mine
0
586
81.39
11.14
32.37
4.10
83.92
31.23
8.67
24.02
Town
0
3.10
0.56
0
0.25
Mine
0
4.70
0.64
0
1.28
Andamooka
0
2.05
0.15
0
0
Town
0
3.60
0.35
0
0
Mine
0
3.90
0.32
0
0
Andamooka
0
0.76
0.06
0
0
Town
0
17.60
3.31
1.29
0.97
Mine
0
35.59
11.30
4.69
3.70
Andamooka
0
28.67
5.51
3.00
2.42
Species
Transect
Rabbits
Andamooka
Cats
Foxes
Kangaroos

Note: the Town and Mine transects were established in 1989 and the Andamooka transect was
established in 2002.
600
500
Rabbits per km²
400
300
200
100
Town
Figure 5-5:
Page 56
Mine
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
0
Andamooka
Three sampling sessions moving average (per km2) for rabbit
abundance at three transects in the Olympic Dam region
1 JULY 2010 - 30 JUNE 2011
4
Cats per km²
3
2
1
Town
Mine
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
0
Andamooka
Three sampling sessions moving average (per km2) for cat
Figure 5-6:
3
Foxes per km2
2
1
Town
Figure 5-7:
Mine
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
0
Andamooka
Three sampling sessions moving average (per km2) for fox
Page 57
35
30
Kangaroos per km²
25
20
15
10
5
Town
Mine
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
0
Andamooka
Three sampling sessions moving average (per km2) for kangaroo
Figure 5-8:
A total of 54 cats and 29 foxes were shot, trapped or tracked and caught within the
Olympic Dam region during FY11 and 66 stomachs were examined for items of prey.
Stomach analysis of these animals found that 190 individual items of prey were evident
(Table 5-2). A majority of the prey items were mammals with one species of bird also
identified. Five fauna species found in cat stomachs were identified, there were eight
rabbits, 43 house mice, 46 hopping mice, five Plains Rats and two Button Quails. Also
present were 85 unidentified small mammal specimens. The data recorded during
FY11 indicates that native fauna species continue to be preyed upon by feral cats and
foxes in the region.
Table 5-2:
Cat stomach analysis results
Prey groups
No. of stomachs
containing prey items
Total individuals
taken
1
1
Rabbit
House mouse
Hopping Mouse (Notomys alexis)
Plains Rat (Pseudomys australis).
8
19
24
3
8
43
46
5
Unidentified Small Mammal
34
85
2
2
Invertebrates
Mammals
Birds
Little Button Quail (Turnix velox)
Total Prey Items
190
5.5 At-risk Species – Category 1a
A number of at-risk species have been recorded or regularly occur within the project
area. At-risk species have been classified by BHP Billiton Olympic Dam into three main
Page 58
1 JULY 2010 - 30 JUNE 2011
categories – Category 1a, Category 1b and Category 2. Appendix 2 contains a flow
chart detailing how priority species are identified. All Category 1a species are
considered ‘at-risk’ as their population as a whole is largely restricted to the impact
area and therefore the species has a higher risk of being impacted. These species are
all formally listed species under state, national and international conservation listings.
The degree of at-risk species monitoring depends largely on the category under which
they fall. Monitoring of Category 1a is intensive in comparison to Category 1b and
Category 2 (Section 2.6), which reflects the species’ reliance on the potential impact
area. A list of all Category 1a fauna occurring in the impact zone is included in
Appendix 3. This includes invertebrates largely restricted to the GAB springs of the
Lake Eyre South region in the vicinity of the wellfields.
5.5.1 Background
A diverse endemic invertebrate fauna occurs in springs associated with the GAB in
South Australia and Queensland. As GAB springs are small aquatic habitats, widely
separated in an arid environment, it has been found that localised groups of GAB
springs support their own specific types of endemic invertebrates (Ponder 1986).
GAB springs in the Lake Eyre South region support at least six species of Hydrobiid in
two genera (Trochidrobia and Fonscochlea), a phreatoicid isopod (Phreatomerus
latipes), an ostracod (Ngarawa dirga) and an amphipod (Afrochiltonia sp.). All these
species are aquatic and are currently only known to occur in GAB springs between
Marree and Oodnadatta (the only known exception is a species of Hydrobiid recorded
in low abundance from Coward Springs Railway Bore) (Ponder et al. 1989). All species
of Hydrobiid present in these springs are currently recognised as internationally
significant (Baillie and Goombridge 1996).
The persistence of GAB spring aquatic invertebrates is intimately linked to the
availability of free flowing water at GAB springs. While the aquatic populations have
been exposed to natural spring processes of emergence and decline over considerable
time periods, it is likely that populations would be susceptible to any accelerated spring
decline over comparatively short time periods, which may be caused by excessive
drawdown.
5.5.2 Purpose
Qualify the level of population change that may be attributed to water extraction from
the wellfields.
Evidence that indicates unacceptable harm or detriment to at-risk species or ecological
communities which can be attributed to drawdown.
5.5.4 Method
Spring groups within the potential impact zones of the GAB are visited triennially and
sampled for the presence/absence of endemic invertebrate species. Sampling is
conducted in the middle year of the Environmental Management Manual (EMM)
triennium, with sorting analysis completed during the final year of the EMM triennium.
Previous research has shown that presence/absence data provides the same level of
information as measures of abundance (Tyre and Possingham 2001). Therefore a
large number of springs are visited and sampled for presence/absence, as opposed to
visiting a small number of springs and providing a quantitative analysis. This enables a
broader impression of current population status to be gained.
Substrate samples are taken at each of the designated springs using a standardised
scoop and tray, and analysed for presence/absence of key fauna species/groups.
Page 59
Time series data are summarised and inspected for long term trends. Baseline data
consists of samples collected during 1995/1996 with further additional sampling
conducted during 1999, 2000, 2002-2005. Monitoring sites are grouped in zones for
analysis based on predicted levels of impact listed in Appendix 5 of the Monitoring
Program – Great Artesian Basin (OLYMPIC DAM Document No: 2789).
Field surveys and sample collection were completed during FY09 with laboratory
analysis completed in FY10. Data analysis was not completed before the deadline for
this report and therefore will be reported on at a later date.
5.6 At-risk Species – Category 1b and 2
5.6.1 Background
Category 1b comprises species for which important populations may be critically reliant
on areas impacted by the operation. Category 1b species are those with local
sedentary populations that are exposed to impact from the operations and have limited
alternate habitat in the region. Also included are highly mobile species that travel in
large numbers and are attracted to hazardous areas within the operation.
Category 2 includes at-risk species whose population as a whole is not critically reliant
on the area of impact, i.e. only individuals of a species are likely to be impacted.
Category 2 species are those that are included under state, national and international
conservation listings and other species which have been recorded in the area that BHP
Billiton Olympic Dam are not legally required to manage but which may also be
adversely impacted by operations (includes some resident un-listed species) (Appendix
2). Species listed as migratory under the Environment Protection and Biodiversity
Conservation Act 1999 are only included under Category 2 if they both occur within the
impact zone and are also likely to be impacted by the operation.
they fall. Category 1b and Category 2 at-risk species are recorded in the region but are
not considered to be confined or dependent on this area. Consequently, there is no
specific management activity which applies to Category 1b and Category 2 at-risk
species, unless a risk-based assessment identifies action by BHP Billiton Olympic Dam
as necessary (i.e. Category 1b and Category 2 species affected by the TRS). If the
understanding of a species risk category changes, Category 1b or Category 2 species
may be elevated to Category 1a, with a subsequent increase in monitoring effort. Fortytwo species of bird, nine species of mammal and one reptile species have been
identified in the Olympic Dam and wellfields region under Categories 1b and 2
(Appendix 3).
5.6.2 Purpose
Determine if there is a requirement to implement any management activity for the
protection of Category 1b or Category 2 species in the vicinity of the operations.


Provide a qualitative assessment of the presence of Category 1b and 2 at-risk
species in the SML and wellfields region; and
Identify if management activity is required for Category 2 at-risk species through a
risk-based assessment (i.e. bird species on the TRS).
5.6.4 Method
Species lists are compiled monthly for all birds sighted in:

The SML;
Page 60
1 JULY 2010 - 30 JUNE 2011
 The surrounding pastoral stations; and,
 The wellfields region.
Category 1b and Category 2 at-risk species of mammals are observed through the
annual field sampling associated with the small mammal and reptile monitoring
(Section 2.2), regular surveys of local water bird populations (Section 2.6), avifauna
monitoring (Section 2.1) and through opportunistic sampling.
Twenty species of Category 1b and 2 birds and five species of mammal were recorded
in the Olympic Dam SML, wider region and the wellfields during the reporting period
(Table 5-3).
Twelve Plains Rats, one Banded Stilt and two Musk Ducks were recorded dead
following interactions with the Tailings Retention System (TRS) during the reporting
period. Management of deaths associated with the TRS is discussed in Section 5.7.
No management activities were required for Category 1b and 2 species during FY11.
Jun
May
Apr
Mar
Feb
Jan
Dec
Nov
Oct
Sep
Species
Aug
Category 1b &2 species recorded in the Olympic Dam and
wellfields region for FY11
Jul
Table 5-3:
Birds

Australasian Shoveler
Australian Bustard

Banded Stilt






Blue-billed Duck










Brolga

Caspian Tern

Cattle Egret

Common Greenshank

Common Sandpiper

Elegant Parrot

Flock Bronzewing


Fork-tailed Swift
Great-crested Grebe





Great Egret
Musk Duck










Peregrine Falcon
Plains Wanderer

Red-necked Stint

Sharp-tailed Sandpiper

Thick-billed Grasswren







Mammals
Burrowing Bettong












Greater Bilby












Greater Stick Nest Rat












Page 61
Jun
May
Apr
Mar
Feb
Jan
Dec
Nov
Oct
Sep
Aug
Species
Jul
Plains Rat












Western-barred
Bandicoot












5.7 Fauna Losses
5.7.1 Background
Priority species of water birds have been recorded in the Olympic Dam area.
Evaporation ponds and tailings storage facilities (which together comprise the Tailings
Retention System – TRS) are sometimes visited by fauna which can result in fauna
deaths (particularly birds and kangaroos). There is the potential for at-risk species of
birds to visit these waste liquor storages. Several engineering controls have been
designed and implemented to minimise these impacts.
5.7.2 Purpose
Assess the performance of control measures that aim to minimise the risk of Category
1b and Category 2 fauna species from entering waste process liquor ponds.


Provide an assessment of fauna activity and losses within the TRS; and,
Provide a quantitative assessment of the numbers of waterfowl using local nontoxic water bodies.
5.7.4 Method
Standardised monitoring of the Evaporation Ponds and Tailings Storage Facilities is
conducted on a weekly basis (each Wednesday) to detect the presence of any fauna
(dead or alive) within the system. This monitoring is conducted by trained staff
members and any fauna carcasses present are removed. This data is not a quantitative
number of fauna using or dying within the system, rather it is used to assess trends and
detect large changes in fauna activity and losses experienced at the TRS. Where
appropriate, data is correlated to changes in management practices or other factors.
Opportunistic observations of fauna using the TRS are also made by trained staff and
technicians.
Monthly bird surveys are conducted at large water bodies where water birds
congregate (i.e. desalination plant, sewerage ponds, and mine water ponds) and also
the TRS. This allows the local population of water birds (especially transient species) to
be determined and compared with those detected at the TRS.
Opportunistic observations of fauna within the TRS continued to be made by TRS
technicians during the FY11 reporting period. Opportunistic observations were also
made by Environment and other staff throughout this period. Standardised weekly
monitoring was undertaken throughout the reporting period.
During the FY11 period a total of 348 mortalities were recorded during standardised
weekly monitoring (Figure 5-9), compared with 148 recorded in FY10 (Figure 5-10).
This year was exceptional as small mammals comprised the majority of deaths (246)
as opposed to birds. A majority of the small mammals that could be retrieved and
identified were introduced house mice. Also observed were 12 Plains Rats and eight
Spinifex Hopping Mice. The increase in numbers of small mammals recorded dead at
the TRS is due to the massive increase in small mammal numbers in the region
following the favourable conditions induced by prolonged above average rainfall.
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1 JULY 2010 - 30 JUNE 2011
Although the Plains Rat is listed as vulnerable under state legislation the death of 12
individuals at the TRS is believed to be a reflection of the current high numbers in the
area. Of the birds, Silver Gulls were the most commonly recorded mortalities with 28
deaths, followed by the Whiskered Tern (12) and Hoary-headed Grebe (10). A small
number of reptiles were also recorded (two Sleepy Lizards, two dragon species, two
snake species, one Central Netted Dragon, one blind snake, one Broad-banded Sandswimmer and one Curl Snake). The numbers of live fauna observed was positively
skewed by Fairy Martins nesting in the area during the first half of FY11. No Fairy
Martins were found dead and they were not observed interacting with the liquor.
160
140
Number of animals
120
100
80
60
40
20
Weekly Monitoring - Alive
Figure 5-9:
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
Weekly Monitoring - Confirmed Dead
Monthly summary of weekly monitoring results for FY11, showing
total number of animals (birds, mammals and reptiles) recorded
within the TRS
Page 63
450
400
Number of animals
350
300
250
200
150
100
50
0
Q1
Q2
Q3
Q4
Q1
Q2
FY06
Q3
Q4
Q1
FY07
Q2
Q3
Q4
Q1
FY08
Q2
Q3
Q4
Q1
FY09
Q2
Q3
Q4
Q1
FY10
Q2
Q3
Q4
FY11
Financial year by quarter
Alive
Confirmed Dead
Figure 5-10: Quarterly summary of all weekly monitoring results, showing total
number of animals (birds, mammals and reptiles) recorded within
the TRS
All fauna observed opportunistically (i.e. outside formal monitoring sessions) during
FY11 are summarised in Figure 5-11. Opportunistic observations bias towards live
animals, especially large flocks, hence more live animals than dead animals are usually
observed.
60
Number of animals
50
40
30
20
10
Opportunistic Observations - Alive
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
Opportunistic Observations - Confirmed Dead
Figure 5-11: Monthly summary of opportunistic observation results for FY11,
showing total number of animals (birds, mammals and reptiles)
recorded within the TRS
Page 64
1 JULY 2010 - 30 JUNE 2011
The data presented indicate the number of fauna counted and do not represent total
numbers. They are presented as an index only. A number of factors must be
considered when interpreting these data and refining our monitoring and data analyses:

Birds may be seen and recorded as alive on one day and subsequently may be
observed as dead. The total includes both observations, leading to a possible
overestimate;
 Scavenging by birds of prey and corvids means that some carcasses may be
removed from the system prior to an observation being made;
 Carcasses floating in the liquor may sink and disappear before being recorded;
and,
 Some fauna species may leave the system and die elsewhere.
The numbers recorded as having been killed by their interactions with the TRS
represent a small proportion of those that visited. Preventing and deterring visitations
by large flocks of birds, particularly Banded Stilts, remains a focus of management
efforts at the TRS.
The large numbers of birds recorded at local non-toxic water bodies continue to
demonstrate the limited number of birds from local and nomadic bird populations that
utilise the TRS (Figure 5-12).
700
600
Number of Birds .
500
400
300
200
100
Local Water Bodies

Jul-11
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
TRS
Note: Observed TRS bird numbers for several months were very low (<3) and may not be visible at
the scale of this graph.
Figure 5-12: Monthly summary of number of water birds recorded at local nontoxic water bodies in comparison to TRS during FY11
An increase in the usage and associated deaths of fauna at the TRS was noted during
2004. This increase was reflected in much higher water bird numbers in regional clean
water bodies and is thought to be largely due to increased bird traffic associated with
seasonal flooding of the Lake Eyre Basin. A public disclosure about this matter was
made by Olympic Dam in January 2005. The increase in observed fauna interactions
prompted the commencement of a research project aimed at investigating risks to
fauna resulting from interaction with the TRS. This project commenced in July 2004
and continued throughout the FY11 reporting period.
Page 65
Activities undertaken during FY11 as part of the project include:

The full time, Scientist Environment (TRS Fauna) role was maintained over the
reporting period;
 Assessment of the effectiveness of current and alternative control measures
(including deterrent systems) continued;
 Trials of sound identification software continued, to determine its efficacy at
identifying waterbird species and its potential use as part of an on demand
deterrent system. The SoundID option is currently being progressed with the option
to develop a Marine Radar system at a later date. Assessments suggest that
SoundID has the potential to be equally or more effective than a marine radar
system;
 Regular meetings of the TRS fauna working group continued;
 Collaborative research between BHP Billiton Olympic Dam and Deakin University
continued. This is an approximately $5 million dollar project conducted over four
years. The research is focusing on two particular areas:
 Using captive birds to determine the most effective light wavelengths and flicker
rates for aversive stimuli in an effort to develop a more effective deterrent. The
critical flicker fusion rate has been determined for a number of wavelengths for
a number of species as has their spectral sensitivities; and,
 Better understanding bird movements between regional water bodies and what
effects these movements e.g. night time light levels and weather patterns in
different regions. In depth movement data has been gathered from 38 Pacific
Black Ducks using satellite transmitters. This has revealed useful patterns of
day/night movement and movement in response to rain etc. The project is now
seeking approval to begin tracking and gathering data from Black Swans.
 Trials designed to determine the durability of HDPE netting and bird balls at the
TRS continued. This will help determine their suitability for use in future tailings
storage facilities.
Future planned activities include:





Ongoing projects assessing water efficiency onsite, to reduce volume of liquor on
the Tailings Storage Facility (TSF);
Continued collaboration with Olympic Dam Projects section regarding future
infrastructure as part of the expansion project;
A trial of netting materials;
Development of the SoundID system; and,
Consideration of the use of offsets for the current impacts at the TRS.
5.8 Conclusion



Avifauna indicators show that the operation appears to have measurable impacts in
close proximity to the operation. The extent appears similar to the previous year.
Gecko gravidity, reptile and small mammal indicators show that the operation
appears to have observed impacts when in close proximity to the operation. High
numbers of the introduced House Mouse influenced scores from small mammal
and reptile monitoring.
Kangaroo, rabbit and fox numbers were lower than the long term mean on all
transects. Cat numbers rose above the long term mean on the mine transect.
Rabbit numbers were nearly double the previous reporting period due to above
average rainfall over FY10 and FY11.
Page 66
1 JULY 2010 - 30 JUNE 2011



GAB spring invertebrate data analysis has not yet been completed and will be
reported on at a later date.
Several Category 2 listed species were recorded in the Olympic Dam SML area
and the wellfields region. Three of the species recorded were within the TRS
system and several other waterbird species have the potential to visit this area.
There were 348 fauna mortalities recorded during weekly monitoring at the TRS in
FY11, which compares to 148 for the previous reporting period. This increase was
largely due to introduced house mice. The TRS Fauna project continued in FY11.
Page 67
6 FLORA MONITORING PROGRAM
6.1 Emission Impacts to Vegetation
6.1.1 Background
Atmospheric emissions from the Olympic Dam mine and processing operation include:

dust from quarrying, mining and milling operations, and vehicle use of tracks.

saline aerosols from raise bore ventilation shaft exhausts, and mist with solvents
from the tailings residue dams and evaporation ponds,the tailings retention
system (TRS).

gaseous and acidic emissions, primarily sulphur dioxide (SO2), other sulphur
oxide gasses, hydrogen fluoride, and heavy metal compounds from the smelter
and sulphur and sulphuric acid production plants.
The largest volume of dust is generated from the Backfill Quarry northwest of the mine
operation and from vehicles conveying quarried material to and from the Backfill plant
and stockpiles. Dust is readily dispersed by wind.
The mine ventilation shafts (raise bores), used for circulating fresh air underground,
intercept two saline aquifers. The water from these aquifers flows into the shafts and is
carried to the surface by the upcast ventilation (upcast raise bores) in the form of a
saline aerosol. The aerosol is released into the environment where it accumulates on
vegetation and in the soil.
Parts of the copper smelting process (flash furnace and anode furnaces) result in the
generation of SO2 and other compounds including copper compounds. The emission of
SO2 from the process plant is controlled through the collection of SO2 rich off-gases for
conversion to sulphuric acid at the Acid Plant. During normal operation, the residual
emissions are vented to the atmosphere via the Acid Plant Tails Stack. Fugitive
emissions captured by the hygiene ventilation system are vented via the Main Smelter
Stack. These low level emissions are continuous. High concentration SO2 emissions
can occur if the off-take gas cleaning system fails. The management of SO2 is
regulated according to the Olympic Dam EPA Licence 1301.
These emissions have the potential to damage vegetation in the areas surrounding the
operation. However, many control measures have been employed to reduce emissions
and hence the impact of the operations. These strategies include improved
environmental engineering and process control.
Research to date (Griffin and Dunlop, 2007 and 2007a) suggests that indicator species
sensitive to atmospheric emissions are Acacia ligulata and Dodonaea viscosa. The
symptoms displayed by these species are used as indicators of Olympic Dam’s impact.
The symptoms may reflect a number of cumulative impacts from aerosols and from
solutes in the soils and systemically in the plants. Sampling has demonstrated a
correlation between the number of symptoms present on both species at a site and the
levels of copper (Cu) and sodium (Na) combined in the foliage of these plants. These
two contaminants each reflect different sources of emissions (the Main Smelter Stack
for Cu, and raise bores for Na) and their different spatial distributions. The two plant
species, A. ligulata and D. viscosa, each respond differently to the contaminant levels.
The combined symptom count provides a simple and robust measure that is
demonstrably linked to emissions levels.
Page 68
FLORA MONITORING PROGRAM
1 JULY 2010 - 30 JUNE 2011
6.1.2 Purpose
To define the impact footprint of BHP Billiton Olympic Dam’s activities, if any, on
vegetation and in particular the indicator species (Acacia ligulata and Dodonaea
viscosa).
Map the impact footprint of BHP Billiton Olympic Dam activities for the Environmental
Management and Monitoring Report.
6.1.4 Method
Monitoring of symptoms occurs within, and surrounding, the Special Mining Lease
surrounding the Olympic Dam operation. Monitoring is centred on the main sources of
emissions: the main smelter stack (as the source of copper (Cu) and SO2), the raise
bores (as the source of saline aerosols) and the Backfill Quarry (as the source of dust).
Sampling is undertaken in two stages:

sample sites are located on a radial grid pattern with the distance between sample
points increasing exponentially out from the centre of the grid (the centre being
near the Main Smelter Stack) to a maximum distance of 25 km to locate the
approximate extent (front) of each of the emissions impacts.
 sampling on a dense though irregular pattern in and around the ‘fronts’ (detected
during the radial sampling) for each of the symptoms to be modelled.
At each location on the radial grid and the ‘front’ sampling, five individuals of each of
the two indicator species, A. ligulata and D. viscosa, are selected to identify the
presence or absence of each of the following 13 symptoms listed below:

necrotic spots, leaf tip necrosis, apical chlorosis, marginal chlorosis, dorsiventral
colour contrasts, deformations, stagging, dead twigs retaining leaves, excessive
leaf abscission, leaf dulling, major new growth, salt crystals and death.
A symptom is recorded as present if evident to any extent and the symptom count is
derived from the percentage of foliage affected. The five individuals are those nearest
the sampling point and within a radius of 50 m of the point. If one or both species are
not present within 50 m of the point, no sample is recorded for the absent species.
In FY11, 24 new sites were added to the sampling grid. Sites sampled in FY11 are
shown in Figure 6-1. During the FY11 monitoring period, sites EV916 and EV928 were
inaccessible due to operational activities. The modelled footprint of detectable emission
levels in plants for FY11 covered 2,500ha. This included a high impact area centred on
the Olympic Dam operation (Figure 6-2). Ignoring two outliers, individual sites with a
‘detectable’ impact were recorded up to 4.5km from the Main Smelter Stack, and sites
with a ‘high’ impact up to 2km from the Main Smelter Stack.
Whilst most sites with symptoms were centred on, and relatively close to, the main
Olympic Dam operation, there were records of dead A. ligulata or D. viscosa at one site
each, 25-26km east or south-east of the operation. As no symptoms were observed on
the sites intervening between these sites and the Olympic Dam operation, these
symptoms at the two outliers were interpreted to be the result of other factors, not the
operation (Griffin and Dunlop, 2010a)
Page 69
Figure 6-1:
Location of radial sample sites and front sites monitored in FY11
The total area modelled as having a ‘detectable’ and ‘high’ impact has remained
reasonably constant since this form of monitoring was introduced, varying between
2,300ha (FY08) and 2,650ha (FY07) (Table 6-1; Figure 6-2). The FY11 figure, 2,500ha,
lies in the middle of this range. This is 100ha larger than that identified in FY10. Where
areas were affected, there were likely to be slightly fewer plant symptoms than in FY10:
the area covered by a ‘high’ impact had decreased whereas that associated with a
‘detectable’ impact had increased.
In FY10 it was suggested that the decreased area in FY10 compared with FY09 may
have partly reflected the higher rainfall in the 12 months preceding the FY10 sampling,
compared with rainfall preceding the FY09 sampling (Griffin and Dunlop, 2009). In
contrast, rainfall prior to the FY11 sampling was even higher than in FY10, yet the
detectable impact had increased slightly rather than decreased. It may be that without
the relatively high rainfall, there would have been a larger increase in detectable
impact. FY11 rainfall data can be found in Appendix 2 (Figure 14-1) of this report. FY10
rainfall data can be viewed in the FY10 EMMR (BHP Billiton 2010e).
Table 6-1:
Areas of modelled impact for symptoms since FY07 and change
between FY10 and FY11 (areas modelled to the nearest 50ha)
Impact category
Change
FY10-FY11
FY07
FY08
FY09
FY10
FY11
Total footprint
2,650
2,300
2,600
2,400
2,500
100
Detectable
2,350
1,600
1,650
1,800
2,000
200
High
350
700
950
550
500
-50
Extreme
0
0
0
0
0
0
Page 70
1 JULY 2010 - 30 JUNE 2011
Figure 6-2:
Modelled distribution of symptoms in FY11 in and about the
operation
6.2 Long Term Changes to Perennial Vegetation
6.2.1 Background
Changes in the composition and structure of vegetation surrounding the Olympic Dam
operation have occurred as a result of emission impacts (Fatchen Environmental,
2005). Fatchen reported that in areas that continue to be affected by emissions,
recovery, either from regrowth of damaged individuals, or recruitment of new plants,
may be depressed or even inhibited.
Whilst the impact to individual plants is currently monitored (Section 6.1), no data is
collected on the long term effect of these emissions, if any, on plant communities,
Page 71
specifically perennial plant communities. Perennial species are persistent and are an
ideal indicator group as they are not likely to change in abundance in response to
season or to most short mesic or xeric periods. Recruitment is likely to be aperiodic
and in response to unusually high rainfall periods (Griffin and Dunlop, 2006).
By collecting annual data at different proximities from the emission sources and using
simple assessment methods, changes in perennial plant communities as a result of
emissions can be monitored.
6.2.2 Purpose
To determine what impact, if any, Olympic Dam Operations has on perennial plant
communities surrounding the operation.
6.2.3 Deliverables


Report on the annual changes in perennial communities surrounding the Special
Mining Lease and surrounds in the Environmental Management and Monitoring
Report.
Provide a comparative assessment on perennial species existing at different
proximities from the main stack.
6.2.4 Method
A total of 46 long term vegetation monitoring sample sites are located in a radial grid
(centred on the Main Smelter Stack) surrounding the Olympic Dam operations. Sites
are located up to 25 km from the centre (Griffin and Dunlop, 2006).The exact locations
of these sites can be seen in Figure 6-1 of this report. Note: EV939, EV929, EV925,
EV911, EV910 and EV940 are not sampled as they do not fit the criteria required for
this sampling.
At each of the sites on the radial grid, a sample quadrat 100m  25m is assessed for
perennial vegetation species. Within the quadrat the frequency of occurrence is
recorded for all perennials. Annual monitoring of these sites and vegetation
composition is undertaken to detect if emission impacts continue and, if so, their effects
on plant communities.
During FY11, 24 new sites were added to the sampling grid. Comparisons with
previous years at these sites was therefore not possible, however the data will be
utilised in future reporting. During FY11 monitoring sites EV916 and EV928 were
inaccessible due to operational activities.
Changes in monitored vegetation
Conditions in FY11 were relatively wet in comparison to previous years, which is the
likely cause for the recruitment of many small A. ligulata growing at most sites (even
ones with no other A. ligulata). Heavy herbage cover prevented an accurate count of
these seedlings. In addition, it was expected that most of these plants would not
survive to FY12. For this reason, it was decided to exclude small A. ligulata from the
count if they were still showing juvenile pinnate foliage. In FY12, a review of which of
these small plants did survive will be undertaken, and the FY11 data adjusted
accordingly, so that only cases of genuine recruitment are included.
Between FY10 and FY11, species composition changed at 42 of the 44 sites where
comparison was possible. Summed over each species and site, the counts of plant
numbers per site changed by 227 plants in FY11 compared to FY10 (in some cases
representing recruitment and in others plant deaths) (Figure 6-2). This was slightly
lower than the change between FY09 and FY10 for the same 44 sites (244 plants).
However, over FY09-10, net plant deaths far outweighed net recruitment, with a net
loss of 114 plants (65 new plants less 179 plant deaths). In contrast, net deaths and
Page 72
1 JULY 2010 - 30 JUNE 2011
recruitments were relatively equal over FY10-11, with a net loss of only nine plants
(Table 6-3).
Table 6-2:
Changes in quadrat species counts FY10-11, for sites sampled in
both years (n=44 sites)
Species
Acacia aneura
No. plants in
FY11
Total
changes
Net
recruited
Net died
17
2
2
0
*
Acacia ligulata
730
104
21
Acacia ramulosa
72
2
1
1
Alectryon oleifolius
81
3
1
2
Dodonaea viscosa
771
50
28
22
Eremophila longifolia
42
8
8
0
Gunniopsis quadrifida
70
39
39
0
Pimelea microcephala
1
1
1
0
Santalum lanceolatum
3
1
0
1
187
17
8
9
1,974
227
109
118
Senna artemisioides
Total (for these species)
83
Note:

Only includes those species whose count per quadrat differed for at least one quadrat between FY10
and FY11. The ‘total changes’ are the sums of net gains (in some quadrats) and net losses (in other
quadrats). Gains and losses within an individual quadrat are not shown; instead the net effect, the
total number of plants, was recorded.

*Note that this figure may be revised upwards, once genuine recruitment can be assessed.
Table 6-3:

Changes in the total number of plants FY07-11, for sites sampled in
over those years
Year
Total no. plants
(28 sites)
Net change from
previous year
Total no. plants
(44 sites)
Net change from
previous year
FY07
1,542
N/A
N/A
N/A
FY08
1,509
-33
N/A
N/A
FY09
1,398
-111
2,150
N/A
FY10
1,327
-71
2,036
-114
FY11
1,348
21
2,027
-9
Note. The numbers of plants reported in Table 6-3 are calculated for sites which were sampled in
FY07-11 (first set of plant numbers), and for the larger set of sites which were sampled in FY10-11
(second set of plant numbers). ‘Net change’ equals net gains minus net losses.
Plant diversity
Simpson’s index is a measure of the extent to which sites were dominated by one or a
few species. Modelled dominance was generally highest near the operation and lowest
distant from the operation (Figure 6-3). Indeed, areas close to the centre of the
operation were modelled with the maximum dominance (1.0, i.e. only one species
present, in this case, A. ligulata). Areas at the perimeter were modelled with greatest
plant diversity at the scale of the model (<0.1). There was, however, a high degree of
variation amongst the more distant sites. The plot of Simpson’s index was very similar
to that in FY10 (cf. Griffin and Dunlop, 2010b).
Page 73
Figure 6-3:
Modelled surface of Simpson’s index. The contours represent the
modelled level of dominance based on the values from the sample
sites (red dots)
6.3 Land Disturbance
6.3.1 Background
Various resource drilling, mine, process and development related activities involve the
clearance of vegetation and ground surface for access tracks, drill pads, drilling sumps,
lay down areas, quarries, surface soil stockpiles, general excavation and waste
management areas. The results of all development activities include:

clearance of topsoil and vegetation (for the construction of drill pads and access
tracks, extraction of sand from dunes and rock quarrying, etc.); and,
 the alteration of surface soils and surface water flows.
All activities that result in land clearance are subject to the Environmental/Indigenous
Heritage Clearance Permit (EIHCP) procedure.
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1 JULY 2010 - 30 JUNE 2011
The extent of land disturbance and the impact of drilling activity are controlled through
site procedures developed with earthworks contractors and drilling crews.
Waste management and infrastructure expansion is subject to the approval of the
appropriate authorities and is regulated through discussions with planning personnel
and site procedures developed with earthworks contractors.
6.3.2 Purpose

Define the disturbance impact footprint of infrastructure, development, resource
drilling and associated waste management activities.

Ensure all disturbance activities have been undertaken in compliance with the
EIHCP system.
Define and map the disturbance impact footprint of Olympic Dam’s activities for the
Environmental Management and Monitoring Report
6.3.4 Method
The extent of physical land disturbance is measured using GIS technology. Georeferenced aerial photographs of the Special Mining Lease and Municipal Lease are
analysed for physical disturbance during the period prior to the photographs being
taken. Evidence of disturbance will be cross-referenced against the EIHCP system
records for the same period. For land disturbance occurring following the capture of
aerial photography through until the end of the reporting period, the area will be
calculated from the EIHCP database.
Spatial analysis techniques were utilised on geo-referenced orthoimagery for the period
June 2010 to July 2011. During this reporting period, satellite imagery of the vast
majority of the SML was captured on a quarterly basis, offering a more accurate
account of the timing of land disturbance. Satellite imagery (captured in July 2010,
October 2010, December 2010 and June 2011) was used in conjunction with aerial
photography of the whole SML (captured in June 2010 and June 2011) to identify new
areas of land disturbance. Disturbances identified as occurring between these dates
were digitised and are represented in Figure 6-4. The total area of disturbance that
occurred between June 2010 and July 2011 is 423.8ha (Table 6-4).
The majority of disturbance in FY11 is attributed to the construction of TSF5 (399.2ha).
Other disturbance areas include the construction of the Tailings Disposal Unit pipe
trace and the expansion of the quarry.
All activities that resulted in land clearance during the reporting period were undertaken
in accordance with the EIHCP process.
Table 6-4:
Areas of disturbance on the SML from June 2010 to July 2011
Facility
Mine Facilities
16.9
Miscellaneous Facilities
Tailings Facilities
1.8
399.2
Exploration
5.9
Total

Area (hectares)
423.8
Note: Disturbance on the SML has been allocated to certain facilities such as mine or tailings etc.
depending upon where they are situated or their purpose. For example, drill pads in the Olympic Dam
Expansion exploration area have been allocated to mine facilities.
Page 75
Figure 6-4:
Page 76
Disturbance on the SML between June 2010 and July 2011
1 JULY 2010 - 30 JUNE 2011
6.4 Pest Plants
6.4.1 Background
Weeds within the Olympic Dam region are managed through the Weed Management
Strategy (BHP Billiton Olympic Dam, 2010a), a collaborative effort driven by BHP
Billiton Olympic Dam, in conjunction with Arid Recovery, the Roxby Downs Municipal
Council and the Andamooka Progress and Opal Miners Association. The Weed
Management Strategy (2010a) takes significant direction from other over-arching
National and Regional Pest Strategies, especially the South Australian Arid Lands
(SAAL) Natural Resource Management (NRM) Pest Management Strategy.
The Weed Management Strategy (BHP Billiton Olympic Dam, 2010a) includes a risk
assessment of weed species that are currently found within the Olympic Dam region or
which may become a problem in future. In the Weed Management Strategy (BHP
Billiton Olympic Dam, 2010a), weeds risk is assessed according to two different habitat
types: Developed and Rangeland. A detailed description of the two habitat types can
be found in the Weed Management Strategy (BHP Billiton Olympic Dam, 2010a),
Section 3.1. Weeds have been ranked, taking into consideration their invasiveness
potential and feasibility to control. Weeds that have an extreme risk or high risk status
are species which Olympic Dam will monitor and control.
6.4.2 Purpose
Determine the extent of weed infestations of extreme risk and high risk weed species
within the Olympic Dam region and Special Mining Lease.
6.4.3
Action Triggers
All infestations of species declared under the Natural Resources Management Act
2004 must be controlled in accordance with the act. Species declared under the Act (as
of Jan 2010) that are knowingly present within the Olympic Dam region are; Prickly
Pear, Innocent Weed, Bathurst Burr, Caltrop, Salvation Jane, Onion Weed and Athel
Pine. African Boxthorn and Horehound are also found within BHP Billiton’s HV
Powerline corridor from Pt Augusta and Olympic Dam. If any declared species are
found on BHP Billiton leased land, control and any government notification
requirements are to be initiated in accordance with the relevant provisions under the
Act.
Define and map the current distribution of extreme risk and high risk weed species
within the Olympic Dam region and Special Mining Lease.
6.4.5 Method
The current distribution of extreme risk and high risk weed species is determined
during scheduled weed monitoring. Comprehensive biennial monitoring is conducted
every 18 months, thereby alternating between a summer survey period and a winter
survey period. Routine and opportunistic monitoring is still conducted in high risk
habitats and previous control locations. Areas surveyed include the Special Mining
Lease, the Municipal Lease, pastoral leases and the Arid Recovery reserve. The next
scheduled biennial monitoring will be undertaken in August 2011.
Routine and opportunistic observations were undertaken throughout the reporting
period as per the Weed Management Strategy. Significantly higher rainfall throughout
the reporting period led to an abundance of various pest plant species growing in
previously unknown areas. A total of 85 plant species have been recorded and
identified as weeds, of which three species have been identified as Extreme risk and
16 identified as High risk ( In many cases a single GPS location may reference a large
Page 77
infestation area, distribution of weeds such as Ruby Dock, Salvation Jane, Caltrop and
Blackberry nightshade may be more extensive than appears on the map below.
In the developed habitat, three species of Extreme risk and 11 species of High risk
were identified; and in rangeland habitat, one species of Extreme risk and seven
species of High risk were identified. Control efforts for these species were undertaken
throughout FY11.
Existing infestations of all known Extreme risk species in a developed habitat were
subject to significant control efforts. Removal of Athel Pine trees continued during FY11
(Figure 6-5) as per EMP targets and action plans. Innocent Weed was continually
monitored and controlled over the summer months (Figure 6-6). It is worth noting that
despite flooding of the infestation areas over FY10-11, the infestation density appears
to be declining at some locations. Noxious Weed information signage was erected at
four earth drains within Roxby Downs to reduce the potential of soil movement where
Innocent Weed (Cenchrus incertus) is present. New infestations of Buffel Grass were
identified and physical and chemical control techniques were implemented. There
appeared to be an increase in the occurrence of infestations along roadsides (main
roads) and this will be closely monitored in the future.
Significant rainfall throughout FY10 and FY11 provided ideal conditions for many weed
species. Extensive infestations of (in particular) Ruby Dock, Salvation Jane and Buffel
Grass emerged. Control of these species was undertaken at several locations on the
SML and ML. It is anticipated that the high rainfall will have had an impact on the
spread of declared plants over future monitoring seasons. The FY11 distribution of
Extreme and High risk species is shown in Figure 6-7 to Figure 6-13. In many cases a
single GPS location may reference a large infestation area, distribution of weeds such
as Ruby Dock, Salvation Jane, Caltrop and Blackberry nightshade may be more
extensive than appears on the map below.
Table 6-5:
Pest plant species that pose an extreme or high risk
Risk
Developed habitat
Rangeland habitat
Page 78
Extreme
High
Buffel Grass
Innocent Weed
Prickly Pear
Athel Pine
Caltrop
Onion Weed
Potato Weed
Salvation Jane
White Cedar
Blackberry Nightshade
Fountain Grass
Paddy Melon
Ruby Dock
Three-Corner Jack
Prickly Pear
Bathurst Burr
Caltrop
Saffron Thistle
Wards Weed
Buffel Grass
Horehound
Salvation Jane
1 JULY 2010 - 30 JUNE 2011
Figure 6-5:
Athel Pine control efforts continued on the SML during FY11.
Seven regenerating Athel Pine plants were controlled along Eagle
Way. Photo taken 5 weeks after control efforts undertaken
Figure 6-6:
Control efforts of Innocent Weed within the Myall Grove reserve
during summer FY11. Example of ‘Noxious Weed’ signage installed
at earth drains in Roxby Downs, where Innocent Weed infestations
are known to occur
Page 79
Figure 6-7:
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1 JULY 2010 - 30 JUNE 2011
Distribution of Extreme and High risk weed species on the SML in FY11
1 JULY 2010 - 30 JUNE 2011
Figure 6-8:
Distribution of weed species at Olympic Dam Village (within the Municipal Lease) in FY11
Page 81
Figure 6-9:
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1 JULY 2010 - 30 JUNE 2011
Distribution of weed species in the Roxby Downs urban area (in the Municipal Lease) in FY11
1 JULY 2010 - 30 JUNE 2011
Figure 6-10: Distribution of weed species in the Arid Recovery reserve in FY11
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Figure 6-11: Distribution of weed species on Andamooka Station (including Andamooka township) in FY11
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1 JULY 2010 - 30 JUNE 2011
Figure 6-12: Distribution of weed species on Roxby Downs Station and Purple Downs Station in FY11
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1 JULY 2010 - 30 JUNE 2011
Figure 6-13: Distribution of weed species on Stuarts Creek Station in FY11
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1 JULY 2010 - 30 JUNE 2011
6.5 GAB Spring Vegetated Wetland Area
6.5.1 Background
The rate of artesian flow from a GAB spring is directly correlated with the area of
vegetated wetland and are also a valuable proxy for the assessment of GAB spring flow
(Williams and Holmes 1978). Changes in the area of vegetated wetland may influence
populations of threatened flora and endemic invertebrates. Changes in wetland area may
be used to assess the extent of aquifer drawdown resulting from water extraction.
Research has proven that GIS techniques can be used to determine the size of vegetated
wetland (Niejalke and Lamb 2002). This method involves less field time and is deemed
more accurate than field assessments.
6.5.2 Purpose
Quantify the change in GAB spring vegetated wetland area that may be attributed to water
extraction from the wellfields.
6.5.3 Action trigger(s)
Evidence that flow reductions (measured as a reduction in wetland area data) at GAB
springs may exceed the predictions made in the Environmental Impact Statement (Kinhill
Engineers 1997) and Kinhill Stearns 1984 (refer to Appendix 5 in the Monitoring Program Great Artesian Basin - OLYMPIC DAM Document No: 2789).
6.5.4 Method
The area of GAB spring wetland is calculated triennially using geo-referenced aerial
photography (Niejalke and Lamb 2002). Imagery is captured in the first year of the
Environmental Management Manual (EMM) triennium, with area reported in the second
year of the EMM triennium. Additional monitoring currently undertaken on the springs,
spring flow rate (biannually) and aquifer pressure (monthly/quarterly), will be used to
identify any gross change and may trigger a field assessment between photography
capture.
The aerial photography of the vegetated wetlands of GAB springs is classified using ER
Mapper software and the classified area is calculated using ArcGIS software. This
technique is not appropriate for some springs due to their small size, or for the small
number of wetlands that do not support wetland vegetation. Therefore, these springs are
assessed using field techniques. To simplify analysis, spring groups are allocated to
predicted impact zones that reflect the anticipated level of hydrological influence caused
by water extraction from the wellfields (see Figure 8.3, Monitoring Program - Great
Artesian Basin - OLYMPIC DAM Document No: 2789). These impact zones are used in
analysis to determine the impact of water extraction from the wellfields. Wetlands may
also be grouped into categories depending on their biological complexity and the elevation
of the spring vent.
GAB spring groups to be analysed using the GIS technique should include those listed in
Appendix 5 of the Monitoring Program - Great Artesian Basin - OLYMPIC DAM Document
No: 2789. Wetland size is compared with the previous reported measurement to
determine the impact, if any, of drawdown. Springs that show a significant difference in
measurement are visited to determine possible causes.
Mound spring imagery was acquired on 20 May 2011, and analysis of this data is currently
being undertaken. Wetland vegetated areas will be reported in FY12 in line with the
triennial reporting process.
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1 JULY 2010 - 30 JUNE 2011
6.6 At-risk Species – Category 1
A number of at-risk flora species have been recorded within the project area. At-risk
species are those where isolated populations or the species population as a whole have
the potential to be adversely impacted by the operations. Species include formally listed
species under state or national conservation listings and other significant species defined
by BHP Billiton Olympic Dam. At-risk species have been classified by BHP Billiton into
three main categories, Category 1a, Category 1b and Category 2.
Category 1a includes those at-risk species whose population distribution as a whole is
largely restricted to the impact area and therefore the species has a higher risk of being
impacted by the operations. This includes flora species restricted to the GAB springs of
the Lake Eyre South region in the vicinity of the wellfields.
they fall. Monitoring of Category 1a species is intensive in comparison to Category 1b and
Category 2 species (Section 2.7), which reflects the species’ reliance on the potential
impact area. A list of all at-risk flora occurring in the impact zone is included in Section 9.
Section 10 contains a flow chart detailing how at-risk species are identified.
6.6.1 Background
A diverse and rare group of flora is found within mound springs of the Great Artesian
Basin in South Australia and Queensland. These landforms occupy an extremely small
percentage of semi-arid Australia, and are probably the rarest landform on the continent
(DEH 2006). Eriocaulon carsonii is a distinctive plant restricted to the active mound
springs of the GAB, where it is reliant on a constant supply of flowing water. The largest
single population exists at the Hermit Hill spring complex near Wellfield A. Eriocaulon
carsonii is listed as endangered by state and national legislation. BHP Billiton Olympic
Dam has the potential to alter the flow of mound spring water within the GAB, which may
have an adverse effect on E. carsonii populations.
6.6.2 Purpose
Determine if the distribution and abundance of E. carsonii is affected by water extraction
from the wellfields.
6.6.3 Action Trigger(s)
Evidence that indicates unacceptable harm or detriment to rare or threatened species or
ecological communities that can be attributed to drawdown caused by extraction from
Wellfields A or B.
6.6.4 Methods
The relative abundance of E .carsonii is estimated using the Domin cover-abundance
scale (Kershaw and Looney 1985). Changes in the cover abundance and the proportion of
GAB springs supporting E. carsonii are used to assess the dynamics of the population. To
simplify analysis, spring groups are allocated to predicted impact zones that reflect the
anticipated level of hydrological influence caused by water extraction from the wellfields
(see Figure 8.3, Monitoring Program - Great Artesian Basin - OLYMPIC DAM Document
No: 2789).
Within the region studied, populations of E. carsonii were restricted to 19 spring units in
the Hermit Hill and Lake Eyre springs complexes in FY11. It occurred on the Hermit (12
units), North West (1), Gosse (3), Sulphuric (1), Old Finniss (1) and West Finniss (1)
spring groups. Eriocaulon carsonii was uncommon and limited in abundance where it did
occur. It ranged in cover class on any one spring unit from 1 (< 0.1% cover) to 6 (26-33%
Page 88
1 JULY 2010 - 30 JUNE 2011
cover), with a median cover of 0.1-< 1%. Eriocaulon carsonii occurred on spring
mounds/springs and spring tails.
Eriocaulon carsonii appeared on ten new spring units between the baseline years and
FY11 (in addition to being transplanted to the spring HSS012). It disappeared from 15
spring units between the baseline years and FY11. Some problems with the historical data
are discussed below, meaning some records of apparent local extinction or re-colonisation
of E. carsonii should be interpreted with caution. Table 6-6 and Table 6-7 include only
those spring groups where E. carsonii has been recorded at some time during or between
1983/4 and FY11.
Between the baseline year and FY11, the distribution of cover classes has shifted. The
higher cover classes of 1983/4 had declined by FY10 and FY11. There have been
significant declines in the Hermit spring group (Table 6-7).
Whilst there were some changes in E. carsonii cover for individual spring units between
FY10 and FY11, the changes were not significant at the spring group or impact zone level
(Table 6-6).
Table 6-6:
Changes in Eriocaulon carsonii abundance, FY10 – FY11 (n=131)
Chi-square
t-test
n
0
1
10
27
1
0
NA
NS
39
Old Finniss
0
0
1
18
0
0
NA
NA
19
North West
0
0
1
33
0
0
NA
NA
34
Gosse
0
0
3
3
0
0
NA
NA
6
Zone total
0
1
15
81
1
0
NA
NS
98
Decreased
Disappeared
Appeared
Showed no change - absent
Hermit
Spring group
Increased
Showed no change - present
Sampling units where Eriocaulon carsonii:
Hermit Hill impact zone
Northern Sub-basin (Lower) impact zone
West Finniss
0
0
1
23
0
0
NA
NA
24
Sulphuric (transplants)
0
0
1
8
0
0
NA
NA
9
Zone total
0
0
2
31
0
0
NA
NA
33

Significance: NS = not significant; NA = not applicable (insufficient data to test)

Note: The chi-square is testing changes in the presence or absence of E. carsonii between the
comparison years (in this case, FY10 and FY11). The t-test tests the change in abundance of E. carsonii
within a spring group.
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1 JULY 2010 - 30 JUNE 2011
Table 6-7:
Changes in Eriocaulon carsonii abundance, baseline – FY11 (n=103)
n
t-test
Chi-square
Appeared
Increased
Decreased
Disappeared
Spring group
Showed no change - absent
Showed no change - present
Sampling units where Eriocaulon carsonii:
Hermit
12
6
0
15
0
5
NS
***
38
Old Finniss
0
0
0
18
0
1
NS
NA
19
North West
0
0
0
6
0
1
NS
NA
7
Gosse
0
0
0
3
0
3
NS
NA
6
Zone total
12
6
0
42
0
10
Sub-total for Hermit and
Old Finniss spring groups
12
6
0
33
0
6
NS
70
***
57
West Finniss
3
1
0
20
0
0
NS
NS
24
Sulphuric (transplants)
0
0
0
8
0
1
NS
NA
9
Zone total
3
1
0
28
0
1
NS
NS
33

Significance: NS = not significant (p≥0.05); NA = not applicable (insufficient data to test), *** p<0.001.

Note. For all spring groups reported in the above table except North West, the baseline year was 1983/4.
The baseline year for the North West spring groups reported here was 1988 (Of the 34 monitored springs
in the North West spring group, the baseline year was variously 1988 (28 spring units), FY06 (4) and
FY07 (2). 1988 E. carsonii data are missing for 21 of the sites with this year as baseline year). As there is
some doubt about the 1983/4 Gosse results, the statistical tests for the Hermit Hill impact zone combined
data have been applied only to the two spring groups with reliable 1983/4 baseline year data.
Between FY10 and FY11, E. carsonii did not change in cover on 15 spring units,
increased in cover on one spring unit, and decreased in cover on one.
Between 1983/4 and FY11, E. carsonii increased in cover (was recorded for the first time)
on nine spring units and decreased in cover on six spring units. However, there is some
doubt as to the accuracy of the 1983/4 records for three of these spring units (reporting
the appearance of E. carsonii at the Gosse spring group). It disappeared from 12 spring
units over this period. The change in cover for the impact zone for this time period was
significant. For those spring units with a 1988 baseline year (from the North West spring
group), E. carsonii was recorded for the first time on one spring unit between 1988 and
FY11.
Between FY10 and FY11, E. carsonii cover was constant on two spring units. E. carsonii
declined in cover on one spring unit and disappeared from three spring units between
1983/4 and FY11. The only other change represents plants transplanted in the intervening
years. The changes in occurrence were not significant at the impact zone level.
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1 JULY 2010 - 30 JUNE 2011
6.7 At-risk Species – Categories 1b and 2
Category 1b includes at-risk species that have an important population (where there are
few other populations within the region or interstate) that may be critically reliant on the
area of impact and the population has the potential to be impacted. Currently there are no
at-risk flora species that fall into category.
Category 2 includes at-risk species whose population as a whole is not critically reliant on
the potential area of impact i.e. only individual species are likely to be impacted. This
includes species which have a wider distribution within the state, interstate or overseas
and are not considered to be dependant upon existing populations within the impact area.
The degree of at-risk monitoring depends largely on the category under which they fall.
Monitoring of Category 1 species (Section 0) is intensive in comparison to Category 2.
6.7.1 Background
There have been 26 at-risk species recorded within the Olympic Dam Special Mining
Lease, Municipal Lease, Pastoral Leases, Transmission Line and the Wellfields area. All
species, with the exception of Eriocaulon carsonni (Section 6.6.1), were found to be nondependent on the populations which exist within the impact area and have been classified
as Category 2. This includes species that are not listed as threatened, but are considered
to be regionally/locally significant. No specific monitoring programs apply to individual
Category 2 species however all at-risk species are protected where possible under the
Environmental Indigenous Heritage Clearance Permit procedure implemented for all
disturbance works related to BHP Billiton activities. This includes species that are not
legally required to be protected but have the potential to be adversely impacted by
operations. If a Category 1b or 2 species is elevated to Category 1a, then a more
intensive monitoring/protection program will be implemented.
6.7.2 Purpose
Determine if there is a requirement to implement any management activity for the
protection of Category 1b and 2 species in the vicinity of the operations.
Identify if additional management activity is required for Category1b and 2 at-risk species
through risk-based assessments.
6.7.4 Method
Locations will be collected opportunistically for annual and or ephemeral at-risk species
after periods of substantial rain and added to the Environmental and Indigenous Heritage
Clearance Permit spatial database for future reference. Locations of these species and
perennial Category 1b and 2 species will be considered when Environmental and
Indigenous Heritage Clearances are undertaken
Category 2 at-risk species are identified during EIHCP assessments and other
environmental surveys. Wherever possible these species are avoided or protected to limit
the impact from operations and associated disturbances. No Category 2 species listed
under state or national legislation have been knowingly disturbed in FY11.
Category 2 flora species impacted by disturbance activities during FY11 are listed in Table
6-8. Acacia aneura and Alectyron oleifolius are common trees species prevalent on the
SML, Municipal Lease and pastoral leases. These species are included in the Category 2
species list as they are long-lived and slow growing species with limited recruitment
opportunities. Efforts are made to avoid these species where possible. During FY11 a
significant area was cleared of vegetation for the construction of Tailings Storage Facility
(TSF) 5, these species were impacted by this disturbance.
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1 JULY 2010 - 30 JUNE 2011
One new population of Orobanche cernua var australiana, a Category 2 species listed as
rare under the National Parks and Wildlife (SA) Act 1972, was identified within the
Wellfield area during the reporting period.
Table 6-8:
Category 2 species identified in areas subject to land disturbance
Species
Impacted by land
disturbance in FY11
New location identified
FY11 (s = seedling) (a =
adult)
Acacia aneura

-
Alectyron oleifolius

-
Orobanche cernua var australiana

6.8 Conclusion






The total area of detectable impact for FY11 was 2,500ha. This is 100ha larger than
that identified in FY10. Where areas were affected, there were likely to be slightly
fewer plant symptoms than in FY10: The area covered by a ‘high’ impact had
decreased whereas that associated with a ‘detectable’ impact had increased.
Twenty four new sites were added to the radial sampling grid in FY11. These sites
enabled baseline data to be collected at more sites at a distance from the existing
operations which should benefit data analysis for the Long Term Vegetation
Monitoring Program when comparisons can be made next year.
The estimated total area of disturbance that occurred between June 2010 and July
2011 was 423.8ha.
Above average rainfall in the year preceding and during FY11 resulted in a high
number of pest plant infestations within the control area. Known infestation areas were
monitored and controlled with a focus on Extreme risk species.
Whilst there were some changes in Eriocaulon carsonii cover for individual spring units
between FY10 and FY11, the changes were not significant at the spring group or
impact zone level.
Two common, locally significant Category 2 species were impacted upon during FY10.
This was the result from continued vegetation clearance associated with the
construction of TSF5 where it was not possible to avoid individual species.
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7 AIRBORNE EMISSIONS MONITORING PROGRAM
7.1 Smelter 2 Emissions
7.1.1 Background
Smelter 2 is one of the major sources of airborne emissions at Olympic Dam and
comprises a Flash Furnace, Electric Slag Reduction Furnace, two Anode Furnaces and
an Acid Plant.
Off-gas from the Flash Furnace is directed to the Electrostatic Precipitator, which removes
particulate matter for recycling to the furnace before being directed to the Acid Plant. Here
the sulphur dioxide (SO2) is converted and absorbed to produce sulphuric acid for use in
the metallurgical plant. Unconverted SO2 is directed to the Acid Plant Tails Gas Stack and
discharged to atmosphere.
Electric Furnace off-gas is directed to a quench tower and venturi scrubber gas cleaning
system before release to the atmosphere via the Main Smelter Stack.
Anode Furnace off-gas is treated in gas cleaning systems similar to that of the Electric
Furnace with the exception of sulphur dioxide rich oxidation gases that are directed to the
Acid Plant for conversion to sulphuric acid.
All furnaces have gas cleaning system bypass stacks in addition to the Main Smelter
Stack and the Acid Plant Tails Gas Stack, for use in abnormal or emergency situations. In
addition, the Acid Plant also has a bypass stack for use in abnormal or emergency
situations in the Acid Plant or during planned maintenance activities.
7.1.2 Purpose
To monitor air emissions from Smelter 2.



Calibration of and record retention for SO2 analysers on the Main Smelter Stack and
Acid Plant Tail Gas Stack.
Compliance with the emission limits, monitoring and reporting requirements of EPA
Licence 1301, EPA Exemption 3014 and the Environment Protection (Air Quality)
Policy 1994.
SO2 recovery of greater than 99%.
7.1.4 Method
The impact of specific emissions on air quality is assessed through monitoring operational
compliance against the requirements and emission limits specified in EPA Licence 1301,
EPA Exemption 3014 and the Environment Protection (Air Quality) Policy 1994.
Olympic Dam maintains systems to report bypass and exceedance emission events in
accordance with statutory and other obligations. If either of the Anode Furnaces, Electric
Furnace, Flash Furnace or the Acid Plant Bypass stacks have been operated for a period
of greater than 10 minutes duration, a report is automatically generated by the process
control system.
Similarly, at the completion of every 12-hour shift (at 0600 and 1800) a report is
automatically generated by the process control system detailing the 30-minute average
SO2 concentrations for the Main Smelter Stack and the Acid Plant Tails Gas Stack for the
duration of the shift. If at any time, SO2 emissions from the Main Smelter Stack or Acid
Plant Tails Gas Stack exceed 2400mg/Nm3 (except during conditions specified in the EPA
Exemption 3014), Olympic Dam is required to notify EPA Regulation and Compliance
within one working day of the event.
AIRBORNE EMISSIONS MONITORING PROGRAM
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1 JULY 2010 - 30 JUNE 2011
All emission events likely to result in an exceedance of the National Environment
Protection (Ambient Air Quality) Measure (NEPM) limits for ground level concentrations of
SO2 are modelled using the CALPUFF Emission Dispersion Model (see Section 2.4). In
the event of an exceedance of the NEPM limits, Olympic Dam is required to notify EPA
Regulation and Compliance within one working day of the event.
All information on bypass and exceedance emission events is compiled monthly to form
the Notification of Emission Events report. This report is submitted to EPA Regulation and
Compliance within ten working days from the completion of the month. All other relevant
information is available to EPA Regulation and Compliance on request.
Isokinetic stack sampling is performed in accordance with condition (305-137) of EPA
Licence 1301. Sampling of Smelter stack emissions and intermediate process gases are
undertaken as necessary to ensure gas cleaning systems are operating optimally and in
compliance with prescribed limits based on process control data obtained from the
process control system. This sampling typically includes analysis for SO2, sulphur trioxide
(SO3), particulates, heavy metals and other chemical compounds. Results from this
sampling are used to update the emission profiles used in the generation of emission
dispersion maps and to validate the continuous emission monitoring (CEM) results.
The SO2 analyser in the Main Smelter Stack which was installed in FY10 had no major
outages during the reporting period. From January to May however readings from the
analyser started to drift. This was caused by an issue with build-up on the internal lens,
combined with contamination of the nitrogen span calibration gas due to the incorrect gas
being supplied. This was rectified by a manufacturer service technician in May. For the
remainder of the period it was maintained in accordance with site procedures and
manufacturers recommendations. A new SO2 analyser was installed in the Acid Plant Tail
Gas Stack in July 2010. For the remainder of the reporting period it was maintained in
accordance with site procedures and manufacturer’s recommendations.
Isokinetic sampling of the Main Smelter Stack and Acid Plant Tail Gas Stack was
undertaken in June 2011. The results indicate continued compliance with the
requirements of EPA Licence 1301 and the Environment Protection (Air Quality) Policy
1994 (Table 7-1). The results have decreased when compared to FY10, however they
remain consistent with measurements from previous monitoring periods.
Table 7-1:
Smelter 2 Stack Sampling Results June 2011
Sampling Point
Total acid gas
emissions*
(mg/Nm3)
Sulphur trioxide
and acid mist
emissions*
3
Particulate
emissions
(mg/Nm3)
(mg/Nm )
3000
100
100
Main Smelter Stack
78
3
16
Acid Plant Tail Gas
Stack
766
3
0.8
Regulatory Limit

* Expressed as sulphur trioxide equivalent
The average SO2 recovery percentage for the reporting period was 97.88%. This recovery
result has decreased from the previous reporting period (99.28%). Notifiable emission
events have increased from 176 events in FY10 to 194 events during FY11, representing
a 10% increase. Considering the Smelter and Acid Plant were both shutdown for
approximately four months in FY10, this reporting period does not represent a full
production year. When comparing FY11 notifiable emission events with FY09 the number
of events has decreased by 25%.
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7.2 Calciner Emissions
7.2.1 Background
The precipitation area of the Hydromet includes two calciners (Calciners A and B), each
with its own off-gas cleaning system and gas discharge stack. Ammonium Diuranate
(ADU) enters the calciners after the completion of the solvent extraction and precipitation
stages of the uranium recovery process. The ADU is calcined to uranium oxide
concentrate (UOC), which is subsequently packed and prepared for shipping. The off-gas
from the individual calciners passes through venturi scrubbers, droplet separators and
mist eliminators to remove particulates prior to release to atmosphere.
7.2.2 Purpose
To monitor emissions of particulates from the calciners.
Compliance with emission limits specified in Environment Protection (Air Quality) Policy
1994.
7.2.4 Method
The impact of specific emissions on air quality is assessed through monitoring the
compliance of processes against emission limits specified in the Environment Protection
(Air Quality) Policy 1994.
Particulate emissions from Calciners A and B are measured on a quarterly basis by
isokinetic sampling, where possible, depending upon process reliability and plant
availability. Any measurement above 250mg/Nm3 is investigated and reported to EPA
Regulation and Compliance within one working day. The isokinetic stack-sampling filters
used to capture particulates are also analysed for Uranium-238 (238U) activity. Results
from this, together with data obtained from the process control system, are used to
estimate total uranium discharged from the stacks, which is subsequently reported in the
LM1 Radiation Annual Report.
Scheduled sampling of the calciner gas cleaning systems occurred in September 2010,
November 2010, May 2011 and June 2011. Scheduled sampling was not undertaken in
February 2011 due to a Processing Plant planned shutdown followed by the unplanned
bogging of Calciner A. Stack testing of Calciner B in May 2011 had to be rescheduled to
June 2011 due to the unplanned outage of the calciner in May when the testing was
planned. Figure 7-1 shows the sampling results for both calciners since FY06.
The results of the sampling (Table 7-2) indicate that emissions from Calciners A and B
met the requirements of the Environment Protection (Air Quality) Policy 1994 during the
reporting period. Particulate emission concentrations measured in samples collected from
Calciner A decreased from an average of 74mg/Nm3 during FY10 to 64mg/Nm3 during this
reporting period. Particulate emissions from Calciner B decreased from an average of
107mg/Nm3 during FY10 to 83mg/Nm3 during this reporting period.
Table 7-2:

Measured particulate concentrations in Calciner Emissions (mg/Nm3)
Calciner A (after mixing)
Calciner B
September 2010
58
136
November 2010
47
49
May 2011
86
Not conducted
June 2011
Not conducted
64
3
Note: Environment Protection (Air Quality) Policy Limit is 250mg/Nm
Page 95
1 JULY 2010 - 30 JUNE 2011
Figure 7-1:
Calciner particulate emissions sample run averages
7.3 Slimes Treatment Plant Emissions
7.3.1 Background
The Slimes Treatment Plant, also referred to as the Gold Room, treats slimes generated
during the electro-refining of copper anodes to produce ingots of gold and silver. This
occurs inside a secure building with fume and emissions extraction provided by one of
three systems; either the roaster scrubber system, the nitrogen oxides (NOx) scrubber
system or general building ventilation.
The roaster scrubber principally treats off-gas from the various roaster and gold and silver
furnaces via a high pressure impaction scrubbing system with subsequent emission to
atmosphere. The NOx gas cleaning system treats fume from the electroplating and aciding
processes via sodium sulphide (Na2S) treatment, followed by scrubbing and emission to
atmosphere. The general building ventilation uses positive pressure created through
constant air-conditioning to remove fume via louvres.
7.3.2 Purpose
To monitor emissions of particulates from Slimes Treatment Plant.
Compliance with the emission limits and requirements of EPA Licence 1301 and the
Environment Protection (Air Quality) Policy 1994.
7.3.4 Method
The impact of specific emissions on air quality is assessed through monitoring the
compliance of processes with the emission limits specified in the Environment Protection
(Air Quality) Policy 1994.
Particulate emissions from the Slimes Treatment Plant are measured on a biannual basis
by isokinetic sampling, where possible, depending upon process reliability and plant
availability. Any measurement above 100mg/Nm3 is investigated and reported to EPA
Regulation and Compliance within one working day.
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1 JULY 2010 - 30 JUNE 2011
Particulate sampling of the Roaster scrubber off-gas was undertaken in December 2011.
The final results for particulates were 127mg/Nm3, which is above the 100mg/m3 licence
condition under EPA Licence 1301. This was due to the fan being operated in manual
mode which decreased the scrubber efficiency. Further stack testing which was
conducted in February 2011 returned particulate results of 54mg/Nm3, which is below the
100mg/m3 licence condition under EPA Licence 1301.
7.4 Ambient Sulphur Dioxide (SO2)
7.4.1 Background
The principal point sources of SO2 at Olympic Dam are Smelter 2 and the Acid Plant.
Small quantities of SO2 are also emitted from diffuse sources (e.g. process vessels). In
accordance with EPA Licence 1301 Conditions (305-139), (305-140) and (305-141),
Olympic Dam conducts an ongoing assessment of SO2 generation, dispersion and
ambient concentration.
7.4.2 Purpose
To monitor the impact of SO2 emissions on ambient air quality.
Compliance with the ground level SO2 concentration requirements of the Ambient Air
Quality NEPM at Olympic Dam Village and Roxby Downs Township.
7.4.4 Method
Modelling of the annual average SO2 ground level concentration, 24-hour maximum and
one-hour maximum SO2 ground level concentrations are completed using a South
Australian EPA-approved computer dispersion model. Modelling is undertaken following
any emission event likely to result in an exceedance of the NEPM limits and on a monthly
and annual basis. A modelled exceedance of the NEPM will be reported to EPA
Regulation and Compliance within one working day of the event. Results of the dispersion
modelling are presented in the monthly Notification of Emission Events report submitted to
EPA Regulation and Compliance within ten working days from the completion of the
month.
The results of the dispersion modelling for the reporting period indicate that no
exceedance of the NEPM for ambient air quality for SO2 occurred over Olympic Dam
Village or Roxby Downs Township (Figure 7-2, Figure 7-3 and Figure 7-4).
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1 JULY 2010 - 30 JUNE 2011
6645
6640
1.00
6635
0.80
Smelter
6630
0.60
6625
Olympic Dam Village
0.081ppm
0.40
6620
Roxby Downs
0.20
0.023ppm
6615
0.00
6610
670
675
680
685
690
695
Note

NEPM Limit 0.2ppm over Olympic Dam Village and Roxby Downs Township.
Figure 7-2:
Page 98
Modelled maximum 1-hour average ground level SO2 concentration,
FY11
1 JULY 2010 - 30 JUNE 2011
6645
6640
0.120
6635
0.100
Smelter
6630
0.080
6625
Olympic Dam Village
0.007ppm
0.060
0.040
6620
Roxby Downs
0.020
0.002ppm
6615
0.000
6610
670
675
680
685
690
695
Note

Figure 7-3:
Modelled maximum 24-hour average ground level SO2 concentration,
FY11
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1 JULY 2010 - 30 JUNE 2011
6645
6640
0.0045
0.0040
6635
0.0035
Smelter
6630
0.0030
0.0025
6625
Olympic Dam Village
<0.001ppm
0.0020
0.0015
6620
0.0010
Roxby Downs
<0.001ppm
0.0005
6615
0.0000
6610
670
675
680
685
690
695
Note

Figure 7-4:
Page 100
Modelled average annual ground level SO2 concentration, FY11
1 JULY 2010 - 30 JUNE 2011
7.5 Fugitive Particulate
7.5.1 Background
Many activities undertaken at Olympic Dam generate some level of fugitive particulate
emission, despite efforts to minimise these emissions. Particulate emissions are
monitored using a passive dust sampling network to determine dust deposition rates and
concentrations of Uranium-238 (238U) contained within the dust.
7.5.2 Purpose
To monitor dust deposition rates and concentration of
dust.
238
U contained within deposited


Characterise the annual dispersion and deposition of particulates.
Characterise the annual dispersion and deposition of 238U contained within deposited
particulates.
7.5.4 Method
Particulate and 238U deposition rate dispersion profiles are generated and analysed to
assess the impact of airborne particulate on ambient air quality.
Fourteen passive dust deposition monitoring sites have been established radiating out
from the operation and at background locations. Samples are collected every month and
analysed for the total quantity of particulates. Six monthly composite samples are
analysed for 238U activity. From these values, dust and 238U deposition rates are calculated
and compared annually to previous monitoring results to assess trends.
During annual flora monitoring a visual inspection of limestone dust deposition is also
assessed at specific monitoring sites. The coverage of limestone on the soil surface is
scored based on six rankings from no dust deposition evident to between 81% and 100%
of the surface covered with limestone dust. These scores represent 4 categories of dust
deposition; undetectable, detectable, high or extreme (Table 7-3). These categories are
then modelled to provide a distribution of dust deposition surrounding the operations.
Refer to Figure 6-1 for the sampling sites.
Table 7-3
Classification of limestone dust deposition on ground surfaces
Rank score
of symptom
Symptoms
Symptom
classification
category
0
No dust deposition evident
1
Between 1 and 20% of surface covered with limestone dust
2
Between 21% and 40% of surface covered with limestone dust
3
4
High
5
Extreme
Undetectable
Detectable
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7.6 Results/Discussion
A map detailing the passive dust monitoring site locations and numbers is shown in Figure
7-5. The average dust dispersion and deposition map for FY11 was developed as
specified and is shown in Figure 7-6.
Dust deposition rates at increasing distances south from site towards Roxby Downs are
shown monthly in Figure 7-7. This supports the previous suggestion that there is distinct
seasonal variation in dust deposition rates throughout the year. Samples were not
collected in January, due to excessive rain and poor road conditions.
Figure 7-8 shows historic dust deposition rates south of the operation on an annual basis.
The results for FY11 are significantly lower when compared with dust deposition rates
from the last reporting period due to the dust storms that occurred in FY10. Dust
deposition results for PD13 however, are slightly higher when compared to previous
year’s results at these locations. With the exception of PD13, the results indicate similar
dust deposition rates to previous reporting periods, excluding FY10.
Figure 7-9 shows the 238U deposition rate at all sites for FY11.
Figure 7-10 indicates that 238U deposition at most sites recorded lower results than
previous reporting periods in line with the reduced dust deposition rates. PD13 and PD14
sample points closest to the townships, returned 238U results below the detection limit. The
only site recording a significant increase in 238U deposition was PD8, however the
increase was not observed at the nearby PD7 site and the result is suspected to be
sample contamination.
Limestone dust deposition was detectable in the area immediately around the backfill and
quarry again in FY11 (Figure 7-11). The modelled area of detectable dust has decreased
however when compared to FY10 and did not encompass areas with a ‘high’ or ‘extreme’
impact (Table 7-4). The distribution is very similar to that observed in FY10 with an overall
slight decrease, which is attributed to the substantial rainfall that occurred in 2010.
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1 JULY 2010 - 30 JUNE 2011
Figure 7-5:
Passive dust monitoring site locations
Page 103
1 JULY 2010 - 30 JUNE 2011
Figure 7-6:
Page 104
Annual passive dust deposition rates measured at monitoring sites,
FY11
1 JULY 2010 - 30 JUNE 2011
400
Dust deposition (mg/m2/day)
350
300
250
200
150
100
50
0
Jul
Aug
Sep
Oct
Nov
PD10
Figure 7-7:
Dec
PD11
Jan
PD12
Feb
PD13
Mar
Apr
May
Jun
PD14
Dust deposition rate by month at sites south of Olympic Dam
900
800
Dust deposition (mg/m2/day)
700
600
500
400
300
200
100
0
FY02
FY03
FY04
FY05
PD10
Figure 7-8:
FY06
PD11
FY07
PD12
PD13
FY08
FY09
FY10
FY11
PD14
Annual dust deposition rate for sites south of Olympic Dam
Page 105
1 JULY 2010 - 30 JUNE 2011
Figure 7-9:
Page 106
Annual 238U deposition rates measured at monitoring sites, FY11
1 JULY 2010 - 30 JUNE 2011
100
90
238
U deposition (mBq/m2/day)
80
70
60
50
40
30
20
10
0
FY01
FY02
FY03
FY04
FY05
PD10
PD11
FY06
PD12
FY07
PD13
FY08
FY09
FY10
FY11
PD14
Figure 7-10: Annual 238U deposition rate by site
Table 7-4:
Modelled impact footprint for limestone dust deposition and change
FY10-FY11 (areas modelled to the nearest 50 ha)
Surface area modelled (ha)
Soil
deposition
category
FY08
FY09
FY10
FY11
Undertaken in
September
Undertaken in
August
Undertaken in
September
Undertaken in
October
Change
FY10FY11
Total footprint
1,050
1,050
800
200
-600
Detectable
1,050
1,050
800
200
-600
High
0
0
0
0
0
Extreme
0
0
0
0
0
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Borefield Road
6638000
6636000
Special Mining Lease
6634000
North
6632000
6630000
6628000
6626000
6624000
672000
676000
680000
684000
688000
East
Legend
Datum: GDA94
Dust deposition class
Projection: MGA94
Undetectable
Detectable
Zone: 53
Operation site feat ure, roads
and boundaries
High
Extreme
Figure 7-11: Modelled distribution of limestone dust deposition in FY11
7.7 Raise Bore Ventilation Shaft Emissions
7.7.1 Introduction
Raise bores are required to ventilate the underground mine. Emissions can be produced
from the raise bores, as the ventilation shafts pass through two aquifers (Arcoona
Quartzite and Andamooka Limestone). Groundwater flows passively into the unlined raise
bores during normal operation, where it may be collected by the updraft of air and
subsequently emitted at the surface as saline aerosols.
7.7.2 Purpose
Monitor emissions of saline aerosols from the raise bores.
Characterise the dispersion and deposition of saline aerosol emissions around the raise
bores.
7.7.4 Method
A system of 26 salt deposition monitoring jars are located within the vicinity of the northern
upcast raise bores, extending 3 km to the north. Salt jars are collected monthly and
analysed for sodium chloride (NaCl), from which a deposition rate is derived. Comparison
with historic data enables broad trending of emission capture efficiency.
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1 JULY 2010 - 30 JUNE 2011
The results of monitoring undertaken during the reporting period are presented in Figure
7-12. Deposition rates for RB10, RB16 and RB19 have maintained historically low levels
during the reporting period. Note that in January 2011, there was no data collected due to
high rainfall. Salt deposition data for February 2011 is a composite of the two months.
Deposition rates for RB21 increased in FY08 due to the deterioration of the mist eliminator
panels. Replacement panels for this raise bore were installed at the end of FY08, leading
to a decrease in emissions in FY09. Emissions for RB21 increased slightly in Q4 of FY09
due to the degradation of mist eliminator panels, which continued during the first half of
FY10. The mist eliminators were replaced in January 2010 which significantly reduced
aerosol emissions in February 2010. Concrete fencing was installed around the raise bore
to intercept aerosol emissions, and repairs were made to five bore pumps to remove the
saline groundwater before it entered the ventilation fan. These improvements have
continued to keep saline aerosol emissions at a low level throughout FY11.
14000.0
12000.0
Salt deposition rate (mg/m2/day)
10000.0
8000.0
6000.0
4000.0
2000.0
RB16
RB19
RB21
RB10
RB29
May-11
Mar-11
Jan-11
Nov-10
Sep-10
Jul-10
May-10
Mar-10
Jan-10
Nov-09
Sep-09
Jul-09
May-09
Mar-09
Jan-09
Nov-08
Sep-08
Jul-08
May-08
Mar-08
Jan-08
Nov-07
Sep-07
Jul-07
0.0
RB30
Figure 7-12: Monthly average of daily salt deposition rate, at monitoring sites 100m
from raise bore
Page 109
1 JULY 2010 - 30 JUNE 2011
7.8





Conclusion
Isokinetic sampling of the Main Smelter Stack and Acid Plant Tail Gas stack indicated
continued compliance with the requirements of EPA Licence 1301 and the
Environment Protection (Air Quality) Policy 1994.
The results of sampling indicate that emissions from Calciner A and B met the
requirements of the Environment Protection (Air Quality) Policy 1994.
No exceedance of the NEPM for ambient air quality for SO2 occurred over Olympic
Dam Village or Roxby Downs Township during the reporting period.
Dust and 238U deposition rates recorded during the reporting period were overall lower
than those measured in previous periods due to above average rainfall throughout the
year.
Salt deposition rates for RB10, RB16 and RB19 are comparable to previous reporting
periods. Deposition around RB21 increased during the first half of FY11, but as a
result of improvement works emissions have been significantly reduced for the
remainder of the year.
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8 ENERGY USE AND GREENHOUSE GAS EMISSIONS
8.1 Energy Use
8.1.1 Background
The main energy sources at Olympic Dam are purchased electricity, diesel and LPG.
Other sources include coke, fuel oil, soda ash, kerosene, oil, grease, sulphur, anode paste
and petrol. The largest consumers of energy at Olympic Dam are the Smelter, Mine and
Mill.
8.1.2 Purpose
The purpose is to monitor and report the energy efficiency of the Olympic Dam operation
overall and that of each area. Reporting of this to the workforce will help drive behaviours
toward energy efficiency opportunities.
The following energy efficiencies will be calculated and made available to site personnel
through Olympic Dam’s Dashboard each month.
Site wide
Energy Efficiency (GJ/t material milled)
Mine
Energy Efficiency (GJ/t hoisted)
Processing
Smelter/Refinery
Energy Efficiency (GJ/t concentrate smelted)
Other
8.1.4 Method
Energy data is obtained primarily from invoices and purchasing records. Sources are
traceable in accordance with the audit requirements of the National Greenhouse and
Energy Reporting Act 2007 (the NGER Act).
Energy from liquid, solid and gaseous fuel use was calculated each month based on data
provided by the Olympic Dam Supply department (sourced from invoices). Energy from
electricity use was calculated based on measurements from onsite metering.
Calculations were performed in accordance with NGER requirements.
Energy efficiency for each plant area and overall for site was calculated monthly and
made available to site personnel through Olympic Dam’s Dashboard. An example of the
information shown each month is given in Error! Reference source not found.. It shows
the actual results for June 2011 and the year to date result (which in this case is also the
overall result for FY11).
Table 8-1:
Actual results of Energy Efficiency for June 2011
Area
Units
June 2011
result
June 2011 Year to Date
(Overall FY11 result)
Site wide
GJ/t material milled
0.62
0.60
Mine
GJ/t hoisted
0.15
0.14
Processing
0.12
0.12
Smelter/Refinery
GJ/t concentrate
smelted
6.79
6.66
ENERGY USE AND GREENHOUSE GAS EMISSIONS
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1 JULY 2010 - 30 JUNE 2011
Area
Other
Units
June 2011
result
0.04
0.05
8.2 Greenhouse Gas Emissions
8.2.1 Background
The main GHG emissions produced due to the Olympic Dam operation are the Scope 2
emissions from electricity generated and supplied to site. The major GHG emitting areas
are the Smelter, Mill and the Mine.
8.2.2 Purpose
To monitor and report GHG emissions of the Olympic Dam operation overall and that of
each area. Reporting of this to the workforce will help drive behaviours toward reducing
GHG emissions.
The following GHG emission intensities will be calculated and made available to site
personnel through Olympic Dam’s Dashboard.
Sitewide
Carbon Equivalent Intensity (kg CO2e/ t milled)
Mine
Carbon Equivalent Intensity (kg CO2e/ t hoisted)
Processing
Smelter/Refinery
Carbon Equivalent Intensity (kg CO2e/ t concentrate
smelted)
Other
8.2.4 Method
Calculation of GHG emissions takes into account all six groups of direct GHG listed in the
Annex A of the Kyoto Protocol (United Nations, 1998) as well as in the National
Greenhouse Gas and Energy Reporting Regulations 2008. Emissions of each type are
weighted according to their Global Warming Potential (GWP) to give a carbon dioxide
equivalent emission value in units of metric tonnes of carbon dioxide equivalent, t CO2e.
The other five direct GHGs listed in the Regulations are:

Methane

Nitrous Oxide

Hydrofluorocarbons (specified)

Perfluorocarbons (specified)

Sulphur hexafluoride
Emissions of Nitrous Oxide (N2O) are unlikely from Olympic Dam’s operations.
Hydrofluorocarbons (CHF2FCF3) are negligible and perfluorocarbons (CF4 and C2F6) apply
mainly to aluminium smelters and thus do not apply to Olympic Dam. Sulphur
hexafluorides (SF6) are also negligible.
Various indirect GHGs are also recorded in Olympic Dam’s reporting process, such as
carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulphur (SOx), and Nonmethane Volatile Organic Compounds (NMVOCs), but since these have no GWP
associated with them, they are not used in the calculation of carbon dioxide equivalent
emissions.
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1 JULY 2010 - 30 JUNE 2011
All calculations and data sources are traceable in accordance with the audit requirements
of the National Greenhouse Gas and Energy Reporting Act 2007. All emission factors are
aligned with NGER guidelines.
Greenhouse gas emissions from energy (liquid, solid and gaseous fuel use) was
calculated each month based on data provided by the Olympic Dam Supply department
(sourced from invoices). Greenhouse gas emissions from electricity use were calculated
based on measurements from onsite metering.
Calculations were performed in accordance with NGER requirements.
Greenhouse gas emission intensities (carbon equivalent intensities) for each plant area
and overall for site were calculated monthly and made available to site personnel through
Olympic Dam’s Dashboard. The FY11 year to date was also given. An example of the
information shown each month is given in Table 8-2. It shows the actual results for June
2011 and the year to date result (which in this case is also the overall result for FY11).
Table 8-2:
Actual results of Carbon Equivalent Intensity for June 2011
Area
Units
June 2011
result
Site wide
kg CO2e/ t material
milled
89
86
Mine
kg CO2e/ t hoisted
20
21
Processing
kg CO2e/ t material
milled
26
26
Smelter/Refinery
kg CO2e/ t
concentrate smelted
817
630
Other
kg CO2e/ t material
milled
5
6
8.3 Conclusion






Site energy use and greenhouse gas emissions (carbon equivalent intensities) were
calculated monthly during FY11. The monthly and year to date results were
communicated to site personnel through Olympic Dam’s dashboard.
The site wide performance for FY11 was 0.60 GJ/t material milled and 86 kg CO2e/t
material milled
The Mine area performance for FY11 was 0.14 GJ/t material hoisted and 21 kg CO2e/t
material hoisted
The Processing area performance for FY11 was 0.12 GJ/t material milled and 26 kg
CO2e/t material milled
The Smelter/Refinery area performance for FY11 was 6.66 GJ/t concentrate smelted
and 630 kg CO2e/t concentrate smelted
The performance for the remainder of the operation for FY11 was 0.05 GJ/t material
milled and 6 kg CO2e/t material milled
Page 113
1 JULY 2010 - 30 JUNE 2011
9 RADIATION DOSE TO MEMBERS OF THE PUBLIC
MONITORING PROGRAM
9.1 Dose to Members of the Public
9.1.1 Background
The primary emission source of environmental radiation exposure from Olympic Dam is
radon, with ingrowth of radon decay products. Radon is emitted from both point and
fugitive sources. Point sources include ventilation shafts (raise bores) and some process
stacks. Fugitive releases of radon may occur from mineral processing and materials
handling activities as well as from ore stockpiles and the tailings storage facility. Airborne
dust containing radionuclides is emitted from the operation.
Olympic Dam has consistently operated in a manner that limits annual radiation dose to
members of the public from operational activities to less than a small fraction of the
1mSv/y limit.
9.1.2 Purpose
To conduct radon decay product monitoring and Radionuclides in Suspended Particulate
Matter for the purpose of calculating radiation dose to members of the public.


Calculation and assessment of annual radiation doses to the critical group i.e.
members of the public with full time occupancy in Olympic Dam Village and members
of the public with full time occupancy in Roxby Downs.
Reporting of results in the annual Environmental Management and Monitoring Report
(EMMR) and the Radiation Protection Annual Report - Licence Number LM1.
9.1.4 Method
The effective dose attributable to radon decay products (EDERn) and radionuclides in dust
(EDED) are calculated and summed to produce the total effective dose (i.e. the annual
radiation dose to members of the public).
Radon Decay Products
Radon decay product concentrations are measured and recorded on a ten minute basis at
powered monitoring stations located at Roxby Downs (RDS) and Olympic Dam Village
(ODV) (Figure 8-1). Meteorological data is acquired from the Bureau of Meteorology
weather station equipped with wind speed and direction sensors. This is located in the
vicinity of the ODV monitoring station at the Olympic Dam Airport and is representative of
meteorological conditions in the operational area.
The radon decay product concentration measurements are captured by data loggers and
are regularly downloaded to the computer network for storage in a database.
The natural background concentrations of radon decay products at ODV and RDS and the
concentrations attributable to the operation are calculated using wind direction to
differentiate the location of the sources. The concentration of radon decay products
measured at ODV and RDS when the wind is blowing from within their respective
operational sectors (i.e. comes from the vicinity of the operation) (Figure 1-1) is deemed to
be comprised of background plus operationally-related radon decay products. Alternately,
when the wind is blowing from directions other than the operational sectors, it is
designated as coming from the background sectors, and the measured concentration of
radon decay products is deemed to be entirely due to natural background sources.
Page 114
RADIATION DOSE TO MEMBERS OF THE PUBLIC MONITORING PROGRAM
1 JULY 2010 - 30 JUNE 2011
Figure 9-1:
Environmental Radiation Monitoring Sites
Page 115
1 JULY 2010 - 30 JUNE 2011
The annual radon decay product concentration attributable to the operation is calculated
at ODV and RDS by:

Subtracting the monitoring site’s mean background sector concentration from the site’s
mean operational sector concentration and then;
 Multiplying the residual by the fraction of time that wind direction was within the
monitoring site’s operational sector.
A threshold wind speed (1m/s) is used to exclude data from the above calculation
because concentrations measured at RDS and ODV below this wind speed are unlikely to
be influenced by radon decay products originating from the operation, and the wind
direction sensor nears the limit of its ability to accurately determine direction at wind
speeds below this value.
BHP Billiton Olympic Dam estimates the effective dose from radon decay products EDERn
(in mSv/y) using the following equation:
EDERn = R x t x DCF
where R is the residual radon decay product concentration (mJ/m3), t is the total number
of hours per year (h/y) and DCF is the dose conversion factor applicable for non-working
residents living at home and is equivalent to 1.1mSv per mJ.h.m-3 (ICRP 1996a).
Radionuclides in Suspended Particulate Matter
The suspended particulate matter monitoring program (using high volume samplers fitted
with PM10 size-selective inlets) yields fortnightly PM10 samples from ambient air for each
monitoring site. The PM10 size-selective inlet is used to ensure only dust of the inhalable
size fraction is sampled.
Background radionuclide concentrations have been measured by a high volume air
sampler fitted with PM10 size-selective inlet at the Roxby Downs Homestead (RDH)
located on Roxby Downs Station, approximately 30 kilometres SSW of the operation.
Analysis of long-lived radionuclide concentrations in dust is undertaken on samples
collected from each of the three sites. The calculation of dose to members of the public
related to the operation involves subtracting the derived background concentrations
measured at RDH from the measured RDS and ODV results.
The dose estimation methods used are provided in ICRP 71, and the DCFs used for each
uranium series radionuclide are specified in ICRP 72.
The mean concentration of radionuclides in dust attributable to the operation is multiplied
by the number of hours of exposure per year, the standard persons breathing rate, and a
dose conversion factor (DCF) that converts the concentration of inhaled radionuclide in
dust into effective dose for that radionuclide (EDR). The formula used is:
EDR = C x h x B x DCF
where C is the mean annual concentration (Bq/m3), h is the number of hours of exposure
per year, B is the breathing rate (m3/h) and DCF is the dose conversion factor (in mSv/Bq)
for the specific radionuclide.
The effective dose from dust (EDD) is then the sum of the effective dose for each of the
long lived radionuclides.
EDD = Σ EDR
Total Effective Dose Equivalent
By summing the two effective dose equivalents, one due to radon decay products (EDERn)
and the other due to radionuclides in dust (EDED), the total effective dose equivalent ED
(in units of mSv/y) for RDS and ODV is obtained.
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1 JULY 2010 - 30 JUNE 2011
Radon Decay Products
Monthly radon decay product averages for the reporting period are shown in Figure 9-2,
together with the five year rolling average.
50
45
Radon concentration (nJ/m3)
40
35
30
25
20
15
10
5
RDS Monthly Average
Figure 9-2:
ODV Monthly Average
RDS 5 Year Rolling Average
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
ODV 5 Year Rolling Average
FY11 radon decay product monthly averages, including five-year
trends
The total doses to members of the public at RDS and ODV due to radon progeny
(including background) were 0.166mSv/yr and 0.134mSv/yr respectively. Both results
were lower compared to previous reporting periods. The major source of error in these
estimates arises from the natural variation of the background radon decay product
concentration. The standard errors associated with these measurements for the reporting
period were 0.002mSv/yr and 0.001mSv/yr respectively. A unit of measurement error was
found in the standard error calculation process and has been corrected for this report.
When background concentrations were subtracted using the method outlined in Section
9.1.4, the mean calculated doses to members of the public attributable to the operation
were 0.009mSv/yr at RDS and 0.006mSv/yr at ODV.
Error analysis conducted on 11 years of monitoring data (Crouch et al. 2003) indicates
that the radon progeny component of the dose calculation methodology is subject to a
minimum detection level of approximately 0.040mSv. That is, it can only determine dose
due to radon progeny from the operation above that value. A result below this detection
level represents a dose less than 4% of the legislated exposure limit of 1mSv/yr.
The dose to members of the public due to operation-related radon progeny at both RDS
and ODV were found to be close to or below the detection level (0.040 mSv). Historic
monitoring data suggests that there is little operation-related radon progeny concentration
at these monitoring sites. Calibration of the radon prism monitors was undertaken in
August 2010 and March 2011. There were a number of periods throughout the year where
the radon prisms were unavailable for sampling due to technical problems or in transport
to and from the calibration facility.
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1 JULY 2010 - 30 JUNE 2011
Radionuclides in Dust
Monthly concentrations of the long-lived radionuclides, 238U, 230Th, 226Ra, 210Pb and 210Po
for the previous five years, are shown in Figure 9-3, Figure 9-4, Figure 9-5, Figure 9-6 and
Figure 9-7. The monthly dust (TSP/PM10) concentration is shown in Figure 9-8. It is
important to note that from FY08 onwards, data is from High Volume Air Samplers (HVAS)
using PM10 size selective heads, which sample only the respirable dust fraction. Previous
years’ data is from TSP sampling heads. The data from FY08 onwards is therefore not
directly comparable with previous years, although comparative analysis of the TSP and
PM10 data during an eight month overlap period indicated that:



Approximately 40-50% of the dust present at RDS and ODV reports as PM10, so
results obtained using the PM10 sampler are expected to be approximately half of the
results using the TSP samplers;
238
U, 230Th and 226Ra radionuclides are distributed fairly equally between sub 10µm
and larger dust particles, so results obtained using the PM10 sampler are expected to
be approximately half of the results using the TSP samplers;
Effectively all 210Pb and 210Po are present in the PM10 dust fraction. TSP and PM10
data would therefore be fairly comparable for these isotopes.
20
Activity (uBq/m3)
15
10
5
RDS
Figure 9-3:
Page 118
Apr-11
Jan-11
Oct-10
Jul-10
Apr-10
Jan-10
Oct-09
Jul-09
Apr-09
Jan-09
Oct-08
Jul-08
Apr-08
Jan-08
Oct-07
Jul-07
Apr-07
Jan-07
Oct-06
Jul-06
0
ODV
238
U concentration for the previous 5 years (in TSP and PM10)
1 JULY 2010 - 30 JUNE 2011
20
18
16
Activity (uBq/m3)
14
12
10
8
6
4
2
RDS
Figure 9-4:
Apr-11
Jan-11
Oct-10
Jul-10
Apr-10
Jan-10
Oct-09
Jul-09
Apr-09
Jan-09
Oct-08
Jul-08
Apr-08
Jan-08
Oct-07
Jul-07
Apr-07
Jan-07
Oct-06
Jul-06
0
ODV
230
Th concentration for the previous 5 years (in TSP and PM10)
35
30
Activity (uBq/m3)
25
20
15
10
5
RDS
Figure 9-5:
Apr-11
Jan-11
Oct-10
Jul-10
Apr-10
Jan-10
Oct-09
Jul-09
Apr-09
Jan-09
Oct-08
Jul-08
Apr-08
Jan-08
Oct-07
Jul-07
Apr-07
Jan-07
Oct-06
Jul-06
0
ODV
226
Ra concentration for the previous 5 years (in TSP and PM10)
Page 119
1 JULY 2010 - 30 JUNE 2011
700
600
Activity (uBq/m3)
500
400
300
200
100
RDS
Figure 9-6:
Apr-11
Jan-11
Oct-10
Jul-10
Apr-10
Jan-10
Oct-09
Jul-09
Apr-09
Jan-09
Oct-08
Jul-08
Apr-08
Jan-08
Oct-07
Jul-07
Apr-07
Jan-07
Oct-06
Jul-06
0
ODV
210
Pb concentration for the previous 5 years (in TSP and PM10)
180
160
Activity (uBq/m3)
140
120
100
80
60
40
20
RDS
Figure 9-7:
Page 120
Apr-11
Jan-11
Oct-10
Jul-10
Apr-10
Jan-10
Oct-09
Jul-09
Apr-09
Jan-09
Oct-08
Jul-08
Apr-08
Jan-08
Oct-07
Jul-07
Apr-07
Jan-07
Oct-06
Jul-06
0
ODV
210
Po concentration for the previous 5 years (in TSP and PM10)
1 JULY 2010 - 30 JUNE 2011
300
Dust Concentration (ug/m3)
250
200
150
100
50
RDS
Figure 9-8:
Apr-11
Jan-11
Oct-10
Jul-10
Apr-10
Jan-10
Oct-09
Jul-09
Apr-09
Jan-09
Oct-08
Jul-08
Apr-08
Jan-08
Oct-07
Jul-07
Apr-07
Jan-07
Oct-06
Jul-06
0
ODV
Total TSP and PM10 concentration for the previous 5 years
The region continued to experience above average rainfall during FY11 which has
resulted in the recording of some of the lowest PM10 and radionuclide concentrations in
recent history. The PM10 results did however follow a seasonal trend throughout the
warmer months. Analysis error estimates have also been presented in Figure 9-3 through
to Figure 9-7 for data from January 2009 to be consistent with recent quarterly
environment reports. Several of the radionuclide activity concentrations were below
analysis error during FY11.
The estimated doses to members of the public at RDS and ODV, due to radionuclides in
dust, including background, were 0.0025mSv/yr and 0.0027mSv/yr respectively.
When background is subtracted from the above figures, the mean doses to members of
the public at RDS and ODV, due to radionuclides in dust and attributable to the operation,
were 0.0003mSv/yr and 0.0001mSv/yr respectively. The operational contribution to dose
was lower than in previous years as some radionuclide activities were below the activities
recorded at the background site. This was due to the above average rainfall causing a
reduction in PM10 and radionuclide concentrations. Error analysis previously conducted on
four years of data indicates that the dose calculation methodology is subject to a minimum
detection level of approximately 0.0080mSv (>0.01%). That is, it can only determine dose
due to radionuclides in dust from the operation above that value.
Thus, the dose to members of the public due to radionuclides in dust at RDS and ODV are
both below the detection limit (0.0080mSv).
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1 JULY 2010 - 30 JUNE 2011
Total Dose to Members of the Public
The total estimated doses to members of the public at RDS and ODV contributed by the
operation were 0.009mSv/yr and 0.006 Sv/yr respectively.
The estimated mean dose to members of the public at RDS and ODV attributable to
operations at Olympic Dam are sufficiently masked by the natural background variations
to be below the detection limits. Thus, the maximum effective dose at both RDS and ODV
is below the detection limit of 0.048mSv/yr for the combined dose from radionuclides in
dust and radon decay products. This effective dose to members of the public is less than
5% of the legislative limit of 1mSv/yr and less than 10% of the operations internal working
limit of 0.5mSv/yr (Figure 9-9).
1.10
1.00
0.90
Dose equivalent (mSv/yr)
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 FY05 FY06 FY07 FY08 FY09 FY10 FY11
RDS
Figure 9-9:
ODV
Detection Limit
Legislative Limit
Total effective dose
9.2 Conclusion



The dose to members of the public due to operation-related radon progeny at both
RDS and ODV were below the detection level of 0.040mSv.
The dose to members of the public due to operation-related radionuclides in dust at
both RDS and ODV were below the detection limit of 0.008mSv.
An effective dose to members of the public of less than the detection limit of
0.048mSv/year was calculated when background dose calculations were subtracted
from measured doses. This value was less than 5% of the legislative limit of
1mSv/year.
Page 122
1 JULY 2010 - 30 JUNE 2011
10 WASTE MONITORING PROGRAM
10.1 Tailings Storage Facility (TSF)
10.1.1 Background
Tailings generated from the hydrometallurgical plant are pumped as slurry from the
tailings disposal surge tanks to the TSF. The tailings are discharged onto the TSF cells via
spigot off-takes from the tailings distribution pipework located at the crest of the perimeter
embankments of each cell of the TSF. Other miscellaneous hazardous or low level
radioactive wastes are also delivered to the TSF as a solid, slurry or liquid.
External perimeter embankments of the TSF are constructed using clayey soil, sand,
crushed rock and tailings. The outer face is covered with rock armouring for erosion
protection and the crest is covered with a crushed road base material to provide a
trafficable surface. Design, construction and operation ensure stability under static and
seismic loading minimises seepage of liquor as far as practicable and minimises erosion
on the outer face.
10.1.2 Purpose
Monitor the operation and performance of the Tailings Storage Facility to identify potential
for adverse environmental impact on soil and groundwater quality.
10.1.3 Deliverables





Monitor the size and location of the supernatant liquor ponds in each TSF cell.
Monitor the rate of rise of tailings in each TSF cell.
Review the water balance on an annual basis.
Monitor the pore pressures within tailings adjacent to the external walls of the TSF.
Fulfil requirements of the Groundwater Monitoring Program.
10.1.4 Method
The monitoring of tailings deposition is conducted in accordance with the Tailings
Retention System Technician Daily Routine (BHP Billiton Olympic Dam 2010f) and the
Tailings Management Plan (BHP Billiton Olympic Dam 2010g). The Tailings Management
Plan incorporates:
 Detailed description of the Tailings Retention System (TRS)
 5 year rolling production plan
 50 year tailings storage plan
 50 year tailings storage financial plan
 Operating plan
 Monitoring plan
 Licensing plan
 Decommissioning and closure plan
Assessment of the size and location of the supernatant ponds is conducted weekly by
visual inspection (BHP Billiton Olympic Dam 2010f). A more detailed estimate of the
location and area of the supernatant liquor pond in each TSF cell are carried out monthly
and reported to regulatory agencies quarterly. Periodic capture of satellite photography
provides accurate size and pond location. Annual overhead aerial photography allows the
accurate calculation of pond area. Oblique aerial photography is performed at a nominal
monthly interval subject to weather and aircraft availability.
WASTE MONITORING PROGRAM
Page 123
1 JULY 2010 - 30 JUNE 2011
The rate of rise of tailings is determined using tailings deposition records and surveys of
the tailings beach at the perimeter of each TSF Cell prior to each tailings embankment
raise.
An annual water balance is calculated from monthly data for the TSF to assess the
ongoing liquor disposal requirements. Data used includes estimates of tailings production
and average tailings slurry density, daily volumes of supernatant liquor decanted to the
EPs, daily records of rainfall and pan evaporation, flows into and within the EPs and daily
liquor levels in the EPs.
An annual operational audit is performed for the TSF by an external tailings consultant.
The annual audit includes a geotechnical assessment of the facility and a water balance.
Standpipe and vibrating wire piezometers are monitored on a regular basis to assess the
pore pressures within the tailings adjacent to the embankments of the TSF. Piezometers
used include standpipe, pneumatic and vibrating wire piezometers. Additional or
replacement piezometers are installed from time to time as required.
Management of Supernatant Ponds
The combined area of the supernatant ponds was within target pond area of 3.0ha per cell
for TSF Cells 1, 2, and 3 during July 2010 and December 2010 but was above for the
remainder of FY11. The area of the supernatant ponds was above target of 13.0ha for
Cell 4 for the entire reporting period (Figure 10-1).
50
45
40
35
Area (ha)
30
25
20
15
10
5
TSF 1-3 Target
TSF 1-3
TSF 4 Target
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
Jun-10
May-10
Apr-10
Mar-10
Feb-10
Jan-10
Dec-09
Nov-09
Oct-09
Sep-09
Aug-09
Jul-09
0
TSF 4
Figure 10-1: TSF Supernatant Pond areas
The combined area of the supernatant ponds on TSF Cells 1–3 varied between 7.6ha and
25.0ha over the reporting period with an average of 15.6ha, an increase of 84% from the
previous year’s average of 8.5ha.
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1 JULY 2010 - 30 JUNE 2011
The supernatant pond area on TSF Cell 4 varied between 22.6ha and 42.5ha over the
reporting period with an average of 30.5ha, an increase of 68% from the previous year’s
average of 18.2ha.
The increase in supernatant pond area over the reporting period was mainly due to
significant rainfall, however low tailings densities and EP2, EP3A and EP3B being out of
service and not available for tailings liquor also contributed.
A satellite photograph of the TRS, taken in early July 2011 is shown in Figure 10-2.
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1 JULY 2010 - 30 JUNE 2011
Figure 10-2: TRS aerial photograph – July 2011
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1 JULY 2010 - 30 JUNE 2011
Tailings Density
The return to full production following an incident at the Clark Shaft in October 2009 can
be seen in the net tailings density (tailings density after allowance for liquor return) shown
in Figure 10-3, which shows a significant decline in net tailings density until it was
recommissioned in May 2010. During FY11, the net tailings density rose steadily from
47.64% in July 2010 to 50.89% in June 2011, with the average over the reporting period
being 49.16%. The average pumped density over the reporting period was 46.72%. The
net tailings density is the adjusted tailings density after liquor returned to the plant is
subtracted from liquor contained in pumped tailings and is a measure of the liquor in the
tailings stream that needs to be stored or evaporated.
100
900,000
90
800,000
80
700,000
70
600,000
60
500,000
50
400,000
40
300,000
30
200,000
Slurry Density (% Solids)
Solids (Tonnes),
Liquor (Kilolitres)
1,000,000
20
No solids to TSF
during Jan 2010
100,000
10
Solids
Liquor
Net Tailings Slurry Density
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Oct-10
Nov-10
Sep-10
Aug-10
Jul-10
Jun-10
May-10
Apr-10
Mar-10
Jan-10
Feb-10
Dec-09
Nov-09
Oct-09
Sep-09
Aug-09
0
Jul-09
0
Tailings Slurry Density
Figure 10-3: Tailings Solids, Liquor and Tailings Density as % Solids
The TSF Cell 4 underdrainage system pumped a total of 51,003kL over the reporting
period. The average pumping rate on days that the pump was operating was 174kL/day
and at the end of the reporting period the average daily pumping rate was approximately
150kL/day. The corresponding average daily pumping rate at the end of the previous
reporting period was 200kL/day. Figure 10-4 shows the pumping rate over the last two
years.
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1 JULY 2010 - 30 JUNE 2011
1000
900
800
700
kL/d
600
500
400
300
200
100
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
Jun-10
May-10
Apr-10
Mar-10
Feb-10
Jan-10
Nov-09
Dec-09
Oct-09
Sep-09
Aug-09
Jul-09
0
Figure 10-4: TSF Cell 4 Underdrainage Pumping Rate
Cycling of Active Tailings Discharge Locations
The location of supernatant ponds is managed such that ponding of supernatant against
perimeter embankments is minimised by practices such as rotation of spigot (deposition)
points.
Tailings deposition is managed to ensure cycling of tailings deposition around each
tailings cell. The locations of tailings deposition in each cell are monitored daily.
Notable operational changes during the reporting period include:



Tailings deposition at 9.25Mt/yr, an increase of 108% compared to the FY10 reporting
period, due to the return to full production rates following recommissioning of the Clark
Shaft.
Continued raising of the walls of TSF Cells 1–3 in 1 metre lifts as follows:
 Fifteenth lift of TSF Cell 2 was completed to RL 128.5mAHD in September 2010
 Fifteenth lift of TSF Cell 3 was completed to RL 128.5mAHD in December 2010
 Sixteenth lift of TSF Cell 1 was completed to a height of RL129.5mAHD in March
2011
 Sixteenth lift of TSF Cell 2 was completed to a height of RL 129.5mAHD in May
2011
Continued raising of the walls of TSF Cell 4 in 1 metre lifts as follows:
 Fourteenth lift of the TSF Cell 4 south wall was completed to RL 122.0mAHD in
December 2010
 Fourteenth lift of the TSF Cell 4 west wall was completed to RL 122.0mAHD in
January 2011
 Fourteenth lift of the TSF Cell 4 north wall was completed to RL 122.0mAHD in
February 2011
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1 JULY 2010 - 30 JUNE 2011
Rate of Rise of Tailings
The rate of rise of tailings has been limited to 2m/annum or less for all cells to ensure
consolidation of tailings material. During the reporting period, tailings were distributed to
TSF Cells 1–4 with an average rate of rise of the perimeter tailings beach of 1.6m/annum.
Tailings delivery to TSF Cell 4 prior to 2003 was biased towards the internal east wall as
the availability of this wall for tailings deposition was largely unaffected by wall-raising
activities, resulting in a higher beach level when compared to the external wall. A plan was
initiated in 2003 to address this issue and bias the tailings delivery to TSF Cell 4 external
walls. Good progress has been achieved during the current reporting period with the
difference in elevation (between the east wall and other walls) decreasing by 0.31m.
No significant impacts have resulted from the difference in height between the internal
east wall and external walls of TSF Cell 4. This issue will continue to be addressed by the
program of reduced deposition to the east wall, gradually bringing it in line with other
walls.
The elevation of tailings in the cells illustrated on Figure 10-5 gives an indication of the
rate of rise of the perimeter tailings beaches. The rate of rise in TSF Cells 1, 2, 3 and 4
were all less than or equal to the target of 2m/annum. The rates of rise for TSF Cells 1, 2
and 3 were 2.0, 1.7 and 1.4m/annum respectively, and for TSF Cell 4 the average rate of
rise was 1.6m/annum for external walls and 1.4m/annum overall.
130
128
126
124
Tailings Beach Level
(m AHD)
122
120
118
116
114
112
110
108
106
104
102
TSF1
TSF2
TSF3
TSF4
Jun-11
Jun-10
Jun-09
Jun-08
Jun-07
Jun-06
Jun-05
Jun-04
Jun-03
Jun-02
Jun-01
Jun-00
Jun-99
Jun-98
Jun-97
Jun-96
Jun-95
100
TSF4 East Wall
Figure 10-5: Elevation of tailings in TSF cells
TSF Water Balance
The water balance for TSF Cells 1–4 indicates that the calculated evaporation factor to
dispose of unaccounted liquor is 51% of the Class A pan evaporation rate (56% for TSF
Cells 1–3 and 46% for TSF Cell 4). The results indicate that during the reporting period
the TSF had the capacity to dispose of excess liquor by evaporation. It is noted that the
unaccounted liquor also includes seepage from beach areas.
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1 JULY 2010 - 30 JUNE 2011
Unaccounted liquor includes input liquor shown in Figure 10-6 (tailings liquor, rainfall,
flushing liquor, and the decrease in supernatant pond inventory) minus liquor retained in
tailings (moisture content assumed of 30% by weight), liquor decanted to evaporation
ponds, and estimated seepage from (supernatant liquor) ponds.
Output liquor is equal to input liquor and is shown in Figure 10-7.
Seepage from pond areas has been calculated based on the average supernatant pond
areas for TSF Cells 1-4 (26.7ha) and an assumed tailings permeability (2x10-8 m/s). Liquor
retained in tailings was assumed to be 30% of the weight of tailings solids deposited
based on previous testing of in-situ tailings.
Note, flushing liquor is liquor pumped out of the evaporation ponds to the TSF for the
purpose of flushing lines or to enhance evaporation.
The water balance shows 9% of liquor input due to rainfall compared to 14% in the
previous reporting period. Rainfall measured for the reporting period was 278.4mm
compared to the previous reporting period of 251.4mm and a median rainfall of 136.2mm.
The increased volume of rainfall input, with the majority falling in February 2011,
combined with increased tailings deposition resulted in a significant increase in the
proportion of liquor decanted to evaporation ponds and an increase in the proportion of
liquor retained in tailings.
Decrease in TSF Pond
Inventory
1%
Flushing Liquor
0%
Rainfall
9%
Evaporation
44%
Liquor with Tailings
90%
Decant to EP's
27%
Retained in Tails
26%
Seepage from Ponds
3%
Liquor Inputs [ TOTAL 10788.324 ML]
Increase in TSF Pond
Inventory
0%
Liquor Outputs [ TOTAL 10788.324 ML]
Figure 10-6: TSF Cells 1 – 4 Liquor
Balance – Inputs, FY11
Figure 10-7: TSF Cells 1 – 4 Liquor
Balance – Outputs, FY11
Pore Pressures
The perimeter of the TSF is monitored on a regular basis to identify any additional
features which develop and to record changes to existing features. Most of the features
observed are minor and the increased moisture is likely to be the result of a localised area
of increased permeability and higher phreatic surface as the height of the TSF increases
over time. A network of piezometers has been installed to monitor pore pressure
distributions within and adjacent to perimeter embankments of the TSF to ensure that
adequate factors of safety are maintained for the stability of embankments.
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1 JULY 2010 - 30 JUNE 2011
A number of areas of increased moisture have been observed around the perimeter of the
TSF. Four new areas (locations 13A, 13B, 15 and 16) have been identified over the
reporting period. All other areas have been reported previously. The areas are shown on
Figure 10-8 and are listed below in Table 10-1.
Table 10-1:
Location
List of perimeter features including their location, discovery date and
status
Location
Discovery
Number
Summary of Status
Date
1
East wall of TSF Cell 1 at the
toe
2008
Damp, no change from previous
reporting period
2
East wall of TSF Cell 1 at the
toe and pipe corridor
2008
Liquor intercepted in trench, no
change in dampness from previous
reporting period. There has been an
increase in the average daily flow
rate from 4 to 6m3/day over the
reporting period.
3
South wall of TSF Cell 1 on
the embankment face
Feb 2008
Becoming drier, no seepage flow
present. Filter Blanket now installed
over area. Quality of seepage
encountered during construction was
found to be neutral.
4
Adjacent to the south wall of
TSF Cell 4
2006
Slightly damp, no change
previous reporting period
from
5
Southwest Corner of TSF Cell
4 on the embankment face
2008
from
West wall of TSF Cell 4 on
the embankment face
2008
from
7
Intersection of TSF Cell 3 and
TSF Cell 4 at toe
Apr 2008
Beneath Cell 3-4 buttress, no change
from previous reporting period
8
Intersection of TSF Cell 3 and
TSF Cell 4 on embankment
face
Apr 2008
Beneath Cell 3-4 buttress, no change
9
Toe of the west wall of TSF
Cell 3
Apr 2008
Beneath Cell 3-4 Buttress, no change
10
West wall of TSF Cell 4 on
the embankment face
2008
Dry, no change from reporting period
11
South wall of TSF Cell 4
adjacent to the toe of the
dune – east of decant pipe
2008
from
12
Cell 2 crest
embankment
starter
2009
from
13,
13A
and 13B
Cell 1 crest of starter
embankment and at toe
2009
13A and 13B growing in size. Liquor
present at surface, but no flow is
present.
14
West wall of TSF Cell 4 at the
embankment toe
2009
15
South wall of TSF Cell 4
(East of Location 11)
Jul 2010
Slightly damp
16
Northeast corner of Cell 3
(North of Location 12)
Dec 2010
Slightly damp
6A
6B
and
of
from
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1 JULY 2010 - 30 JUNE 2011
Figure 10-8: Location of perimeter features monitored regularly
A brief description of selected locations and commentary on any significant changes over
the reporting period is provided below.
Location 3 – Cell 1 South Side – Face of Embankment
An area of increased moisture content was identified in February 2008 and is shown in
Figure 10-9. Investigations indicate the area is adjacent to an old causeway. A network of
18 standpipe piezometers and 7 trial vibrating wire piezometers have been installed to
monitor the area. A schematic cross section for 10 of the piezometers and the 7 vibrating
wire piezometers is shown in Figure 10-10 for the south side of TSF Cell 1. Hydrographs
for the piezometers are shown in Figure 10-11. A steady trend with upper level
piezometers shows an increasing water level in response to increased tailings deposition
rates since the Clark shaft incident in October 2009. Ponded water on the surface has
been tested and is neutral and low in copper and uranium indicating it could be
neutralised tailings liquor or stormwater. The vibrating wire piezometers are currently out
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1 JULY 2010 - 30 JUNE 2011
of service due to problems with the instrument that reads the piezometers. A buttress was
constructed over Location 3 during May and June 2011 to minimise the potential for piping
(internal erosion through the embankment). During construction, seepage quality was
tested and the results showed that the seepage was neutral.
Figure 10-9: Photo of location 3 in August 2011 showing buttress
VWP11
VWP12
VWP13
130
125
TP50
TP48
TP51
TP49
Elevation (mAHD)
120
TP45
TP47
TP44
TP46
VWP7
VWP8
VWP9
VWP10
Hydrostatic
Pressure
Line
TP56
115
110
TP39
105
100
200 740
200 760
200 780
200 800
200 820
200 840
200 860
200 880
Northing (m)
Figure 10-10: Schematic cross section through south side of TSF Cell 1 – June 2011
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130
125
Water Level mAHD
120
115
110
105
100
TP39
TP46
TP53
VWP10
TP41
TP48
TP55
VWP12
TP42
TP49
TP56
VWP13
TP43
TP50
VWP7
Jun-11
Apr-11
May-11
Mar-11
Jan-11
TP44
TP51
VWP8
Feb-11
Dec-10
Oct-10
Nov-10
Sep-10
Jul-10
Aug-10
Jun-10
Apr-10
May-10
Mar-10
Jan-10
Feb-10
Dec-09
Oct-09
Nov-09
Sep-09
Jul-09
TP40
TP47
TP54
VWP11
Aug-09
Jun-09
Apr-09
May-09
Mar-09
Jan-09
Feb-09
Dec-08
Oct-08
Nov-08
Sep-08
Jul-08
Aug-08
Jun-08
95
TP45
TP52
VWP9
Figure 10-11: TSF Cell 1 South Wall Piezometer Hydrographs
Locations 7, 8 and 9 – TSF Cell 3 west /TSF Cell 4 north
Liquor was observed at the toe of the west wall of TSF Cell 3 in April 2008. Installation of
a permanent engineered liquor interception system was completed in March 2009 and an
engineered filter and buttress was installed in June 2010.
A dewatering bore was installed into the mullock starter embankment of TSF Cell 3 which
has reduced the seepage rate to approximately 3kL/d (Figure 10-12).
150
Dewatering bore
commissioned
13 May 2010
140
130
120
110
Flow (kL per Day)
100
90
80
70
60
Seepage flow
reduced from
105 kL/d to
3 kL/d
50
40
30
20
10
Total Flow
14 per. Mov. Avg. (Total Flow)
01-Jun-11
01-Apr-11
01-May-11
01-Mar-11
01-Feb-11
01-Jan-11
01-Dec-10
01-Nov-10
01-Oct-10
01-Sep-10
01-Aug-10
01-Jul-10
01-Jun-10
01-May-10
01-Apr-10
01-Mar-10
01-Feb-10
01-Jan-10
01-Nov-09
01-Dec-09
01-Oct-09
01-Sep-09
01-Aug-09
01-Jul-09
01-Jun-09
01-May-09
01-Apr-09
01-Mar-09
01-Jan-09
01-Feb-09
01-Dec-08
01-Oct-08
01-Nov-08
01-Sep-08
01-Jul-08
01-Aug-08
01-Jun-08
01-May-08
0
91 per. Mov. Avg. (Total Flow)
Figure 10-12: TSF Cell 3 daily seepage liquor flow
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U308
91 per. Mov. Avg. (U308)
PH
14 per. Mov. Avg. (PH)
pH
01-Jun-11
01-Apr-11
01-May-11
01-Jan-11
01-Feb-11
01-Mar-11
01-Dec-10
0.0
01-Oct-10
0
01-Nov-10
0.5
01-Sep-10
25
01-Jul-10
1.0
01-Aug-10
50
01-Jun-10
1.5
01-Apr-10
75
01-May-10
2.0
01-Jan-10
100
01-Feb-10
01-Mar-10
2.5
01-Dec-09
125
01-Oct-09
3.0
01-Nov-09
150
01-Sep-09
3.5
01-Jul-09
175
01-Aug-09
4.0
01-Jun-09
200
01-Apr-09
4.5
01-May-09
225
01-Jan-09
5.0
01-Feb-09
01-Mar-09
250
01-Dec-08
5.5
01-Oct-08
6.0
275
01-Nov-08
300
01-Sep-08
6.5
01-Jul-08
325
01-Aug-08
7.0
01-Jun-08
350
01-May-08
U308 mg/L
Chemical analysis of the liquor is also recorded on a regular basis and is shown in Figure
10-13. During the reporting period, the concentration of U3O8 had reduced to near
background levels, and the pH had increased to near neutral. However, the 14 day
moving average U3O8 concentration has increased to a peak of 85 mg/l and then reducing
to 40mg/l, and the pH has decreased to 4.9. Investigations into the cause of the change
are currently being undertaken but it appears to be associated with an increase in flow
rate following significant rainfall in February 2011.
14 per. Mov. Avg. (U308)
91 per. Mov. Avg. (PH)
Figure 10-13: TSF Cell 3 liquor analyses
Location 13A & 13B – TSF Cell 1/2 East
Two areas of increased surface moisture were identified in July 2010 during regular
embankment inspections. These are located within the pipe trace adjacent to Lower Valve
Station 2, on the east side of TSF Cell 1/2. The moist areas were initially very small,
however, they have steadily grown over the reporting period (Figure 10-14). There is
liquor present at the surface, however no seepage flow is present. Piezometer TP88,
located at 13A is dry. However, TP176 which is located within Cell 2, east of Location
13B, shows a head of approximated 10m above the natural surface (RL110 mAHD). This
could indicate a potential flow path through an existing sand dune within the dam, which
then connects to the mullock starter which forms the east wall of Cell 2. It is planned to
install a seepage trench similar in design to Location 2 as a precautionary measure.
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Figure 10-14: Photograph of Location 13B looking North in July 2011
Project Progress
Progress highlights of current projects are provided below:




Raising EP Embankments
 2 metre wall raise to EP1
 Commissioned successfully in July 2010
Stability Review
 A further 9 Standpipe piezometers were installed
 Stability assessment undertaken to investigate TSF Cells 1-3 potential height
increase from 30m to 34m.
 Design and installation of a buttress on South Wall TSF Cell 1.
TSF Cell 5
 Continued construction of TSF Cell 5
 Commissioning planned to commence in FY12
Tailings Disposal Upgrade
 Construction of a staged upgrade commenced with commissioning of the first
stage to coincide with commissioning of TSF Cell 5 East.
10.2 Evaporation Ponds (EPs)
10.2.1 Background
Olympic Dam operates five EPs. The principal function is the storage and evaporation of
surplus tailings liquor decanted from the TSF.
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The crests of the EPs are profiled such that there is a uniform cross fall from the outer
edge to the inner edge and a constant level is maintained around the perimeter of each
cell. A bund is included on the outer edge as a contingency to contain any liquor that
overtops the ponds due to wind and wave action.
Liquor evaporates and concentrates in the evaporation cells, resulting in precipitation of
solids, principally iron sulphate. A programme has been developed to minimise the
precipitation of solids and is currently being implemented.
10.2.2 Purpose


Monitor the operation and performance of the EPs to identify potential for adverse
environmental impact on soil and groundwater quality.
Monitor the liquor inventory in the EPs to assess the evaporation capacity of the ponds
in relation to the volume of surplus liquor reporting from the TSF and assist in the
liquor management within the TRS.
10.2.3 Deliverables




Monitor the liquor level in each cell of the EPs to maintain adequate freeboard to
prevent overtopping of the embankment crest.
Monitor the overall (solids and liquor) inventory in the EPs.
Conduct a liquor balance of each evaporation cell to highlight potential significant
leaks.
10.2.4 Method
EP levels are measured using a combination of laser, radar and manual measurements
depending on the level of solids build-up in the cell and access provisions in each cell (eg
stilling wells or jetty). EPs are inspected and liquor levels are recorded on a daily basis
(BHP Billiton Olympic Dam 2010f). Stored volume (liquor and solids) is calculated from
daily liquor level measurements to enable freeboard and overall EP (solids and liquor)
inventory to be determined.
A liquor balance is performed to highlight cells with potential significant leaks by
comparison of the apparent evaporation from each cell of each EP. The comparison is
carried out on a monthly basis and presented to regulatory agencies in a quarterly report.
Tailings Retention System Seepage (ID 3.2) within the Environmental Management
Program (BHP Billiton Olympic Dam 2010b) describes a number of management controls
in place to control environmental impacts. Monitoring is conducted to assess the
performance of the controls.
Detection of Seepage
Seepage from the ponds is identified by piezometers in and around the ponds and liquor
balance calculations. The former is addressed in detail in Section 3. Figure 10-15 shows
the cumulative evaporation trends for EP1 and EP2. Figure 10-16, Figure 10-17 and
Figure 10-18 show the cumulative apparent evaporation trends for Evaporation Ponds 3, 4
and 5 respectively. Figure 10-19 shows the comparison of cumulative evaporation for all
cells. The upper and lower bounds have been calculated using the average evaporation
rate from all operational cells and applying an estimated error or variation (plus or minus)
to the average value. The performance of each of the evaporation ponds is discussed in
further detail below.
Evaporation cells occasionally ‘dry out’ when all free liquor is evaporated, exposing the
surface of the solids sludge built up in the cell. During these periods a liquor level is not
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1 JULY 2010 - 30 JUNE 2011
able to be measured and therefore the cumulative evaporation trends level out and the
water balance method is no longer effective in confirming cell integrity. However, as the
cell is ‘dry’ there is little if any free liquor available and therefore very little potential for
significant seepage from the ‘dry’ cells.
EP2 was out of service at the start of the reporting period after movement of some of the
wave barriers, and was returned to service during November 2010.
EP3A was out of service due to high level of precipitated solids for the entirety of the
reporting period. The trend in EP3B was consistent with other fully operational cells as
shown in Figure 10-19. EP3B dried out in May 2010, and is currently out of service due
liner damage identified in September 2010.
The trends in EP4A and EP4B were consistent with each other as shown in Figure 10-17
and with other operational cells as shown in Figure 10-19.
The trends in EP5A and EP5B were consistent with each other as shown in Figure 10-18
and with other operational cells as shown in Figure 10-19.
Figure 10-19 shows the comparison of cumulative evaporation for all evaporation cells.
The upper and lower bounds have been calculated using the average evaporation rate
from the ‘non-dry’ cells that have been fully operational during the period.
2400
2200
2000
1800
Evaporation (mm)
1600
1400
1200
1000
800
600
EP2 Recommissioned
400
200
EP1
EP2
Upper Bound
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
Lower Bound
Figure 10-15: EP1 and EP2 Liquor Balance – cumulative apparent evaporation
trends
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2400
2200
2000
EP3B Dry
1800
Evaporation (mm)
1600
1400
1200
1000
800
EP3A Dry
600
400
200
CELL 3A
CELL 3B
Upper Bound
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
Lower Bound
Figure 10-16: EP3 Liquor Balance – cumulative apparent evaporation trend
2400
2200
2000
1800
Evaporation (mm)
1600
1400
1200
1000
800
600
400
200
CELL 4A
CELL 4B
Upper Bound
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
Lower Bound
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1 JULY 2010 - 30 JUNE 2011
2400
2200
2000
1800
Evaporation (mm)
1600
1400
1200
1000
800
600
400
200
CELL 5A
CELL 5B
Upper Bound
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Jul-10
Aug-10
0
Lower Bound
2400
2200
2000
1800
Evaporation (mm)
1600
1400
1200
1000
800
EP3A Dry
600
EP2 Recommissioned
400
200
CELL 1A
CELL 2C
CELL 5A
CELL 1B
CELL 2D
CELL 5B
CELL 1C
CELL 3A
Upper Bound
CELL 1D
CELL 3B
Lower Bound
CELL 2A
CELL 4A
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
CELL 2B
CELL 4B
Figure 10-19: All EP Liquor Balance – cumulative apparent evaporation
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1 JULY 2010 - 30 JUNE 2011
Freeboard
Figure 10-20 shows the evaporation pond capacity in relation to the normal maximum
operational storage capacity. Additional capacity is provided as a contingency for extreme
rainfall events and allowance for waves.
At the end of the previous reporting period, evaporation pond capacity had been modified
by the addition of a 2 metre embankment raise to EP1. During the current reporting period
the evaporation pond capacity was revised to reflect the recommissioning of EP2 storage
capacity and the removal of EP3B storage capacity from service in September 2010.
Reported liquor inventory in the evaporation ponds as a proportion of storage capacity
was 109% of the normal maximum operational level (NMOL) at June 2011.
EP3B out of
service
EP2
recommissioning
5500
5000
4500
4000
Volume (ML)
3500
3000
2500
2000
1500
1000
500
Contingency
EP Volume
Normal Max. Ops Level
Jun-11
May-11
Apr-11
Mar-11
Feb-11
Jan-11
Dec-10
Nov-10
Oct-10
Sep-10
Aug-10
Jul-10
0
Emergency Limit
Note:

Normal operation and contingency limits revised to reflect the removal of EP3B storage capacity from
service and the addition of recommissioned EP2 storage capacity.
Figure 10-20: Evaporation pond capacity
10.3 Mine Water Disposal Pond (MWDP)
10.3.1 Background
Water pumped from the Olympic Dam underground workings originates predominantly
from the Arcoona Quartzite geological unit. The Arcoona Quartzite geological unit is
fractured in its lower sections and yields water into the mine ventilation shafts, decline,
haulage shafts and drill holes. The orebody and its host rocks generate little or no
groundwater flows into the workings.
Water collected from the mine is pumped to the surface storage (settling) ponds to allow
for the slimes and fine particles to settle and “clean” water to be collected and re-used on
site for dust suppression, soil conditioning during construction or underground mining
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1 JULY 2010 - 30 JUNE 2011
activities or is discharged to the MWDP for subsequent evaporation and recharging of the
Andamooka Limestone aquifer (BHP Billiton Olympic Dam, 2009).
Operational improvements have maximised the reuse of mine water and therefore
minimised the disposal of saline water to the MWDP. As a result the MWDP is used on an
intermittent occasional basis and therefore the risk of overtopping is minimal.
10.3.2 Purpose
To monitor the operation and performance of the MWDP to identify potential for adverse
environmental impact on soil and groundwater quality.
10.3.3 Deliverables(s)
Maintain freeboard levels to within the maximum operational capacity.
10.3.4 Method
There are no current operational methods for monitoring Mine Water Disposal Pond
levels. Quantities disposed of into the pond are captured in the Mine Water Balance.
Water levels of the mine water settling ponds are monitored via Citect. Settled sludge is
removed and disposed to the TSF.
Water was discharged to the MWDP during FY11. Daily inspections were undertaken in
accordance with the document (BHP Billiton Olympic Dam 2011b).
Monitoring requirements of the Groundwater Monitoring Program (BHP Billiton Olympic
Dam 2010c) were fulfilled and are discussed in Section 4.
10.4 Site and Olympic Village Sewage Ponds
10.4.1 Background
Olympic Dam operates two onsite anaerobic sewage ponds and four anaerobic sewage
ponds located at Olympic Dam Village. Their principal function is to contain and facilitate
the anaerobic treatment of sewage from the metallurgical plant, mine and Olympic Dam
Village.
10.4.2 Purpose
Monitor the operation of the Sewage Ponds to minimise impact on soil and groundwater
quality.
Monitor sewage ponds to identify potential for adverse environmental impact.
Fulfil requirements of EPA Licence 3054.
10.4.4 Method
Sewage Ponds are inspected on a daily basis to identify potential for adverse
environmental impact.
The sewage ponds at Olympic Dam Village (ODV) were monitored in accordance with the
document (BHP Billiton Olympic Dam 2011b). Daily visual inspections were undertaken of
the sewage ponds on site, and water quality monitoring was undertaken monthly.
The requirements of EPA Licence 3054 were fulfilled.
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10.5 Waste Management Centre
10.5.1 Background
Most of the industrial and general waste materials generated at Olympic Dam are
managed through the Waste Management Centre, which is located north-west of the
Smelter and south of the quarry.
An ongoing program has been established to minimise waste disposed to landfill through
increased reuse and recycling. Recovered scrap material is cleaned and undergoes a
formal radiation clearance procedure prior to leaving the site. The Waste Management
Centre incorporates various categorised lay-down areas for the temporary storage of
materials nominated for reuse or recycling.
Material which cannot be reused or recycled is disposed of to the landfill facility, which is
also located within the Waste Management Centre. At the landfill face, waste materials
are deposited in thin layers and covered with clean fill material to facilitate containment of
waste. Miscellaneous low level radioactive contaminated waste is disposed in the landfill.
The Waste Management Centre is enclosed on all sides by either a two-metre high mesh
fence topped with strands of barbed wire or a bund of height at least 1.5m. This is
designed to restrict unauthorised access and function as a secondary litter containment
control.
10.5.2 Purpose
Monitor the disposal and recovery of industrial and general wastes to identify opportunities
to minimise resource use intensity.


Record quantities of general and industrial waste disposed of to landfill.
Record quantities of material recovered for reuse and recycling.
10.5.4 Method
Waste materials generated across site are collected by the waste management contractor
in a dedicated waste collection vehicle for recovery or disposal. At the time of collection,
the operator of the vehicle records the quantity of the material and collection location
where appropriate. In cases where material is delivered to the Waste Management Centre
by operations personnel, the quantity, type and source of the material is recorded at the
Waste Management Centre office prior to being placed in storage for subsequent recovery
or disposal to landfill.
The waste management contractor is responsible for processes associated with the
reception, disposal, storage and recovery of waste materials and the control and operation
of the Waste Management Centre facilities.
Olympic Dam maintains systems to record quantities of industrial and general waste
generated and subsequently disposed of or recovered for reuse or recycling. The waste
management contractor is responsible for maintaining such records, which is entered into
an electronic register. These include:

Cardboard collected.

General waste collected.

Waste disposed of in the TSF.

Materials sent off site for recycling.
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From waste collection records, including waste delivered to the Waste Management
Centre, it is estimated that approximately 35,922m3 (loose fill) was transported to the
Waste Management Centre in FY11. This is a decrease of 3% on the volume of waste
delivered to the Waste Management Centre in FY10.
Bin records also show that approximately 787m3 of paper and cardboard waste was
collected for recycling in FY11, a decrease of 10.5% of the volume collected in FY10.
10.6 Miscellaneous Hazardous Wastes
10.6.1 Background
Miscellaneous hazardous wastes such as laboratory chemicals, process chemicals and
process waste materials are generated on an ongoing basis at Olympic Dam and require
appropriate disposal.
Olympic Dam maintains systems and processes to control and administer the disposal of
hazardous waste. Designated HSE personnel provide advice on the disposal of
hazardous waste and authorise waste disposal within the Special Mining Lease (SML)
primarily to the Tailings Storage Facility or Waste Management Centre. Low level
radioactive waste is disposed in the TSF. Hazardous waste unsuitable for disposal within
the SML is transported off site to an appropriate waste depot for further treatment,
recycling or disposal. Off site disposal of hazardous waste categorised as listed waste
(within the meaning of the Environment Protection Act 1993) is transported by an EPA
licensed transporter to an EPA licensed waste depot and is undertaken in accordance
with EPA guidelines for waste transport and tracking.
10.6.2 Purpose
Manage miscellaneous hazardous wastes in an appropriate manner.


Record categories, quantities, and location of hazardous waste materials disposed
of within the SML.
Comply with the requirements pertaining to listed waste in EPA Licence 1301.
10.6.4 Method
The disposal of hazardous waste is managed by the waste management contractor
through the Waste Management Centre. Each material requiring disposal is assessed and
the most appropriate disposal option is chosen.
Olympic Dam maintains systems to record categories, quantities and location of
hazardous waste materials disposed of within the SML. The waste management
contractor is responsible for maintaining such records.
The transport of hazardous waste off site is documented through the EPA waste transport
and tracking system as required to provide assurance to regulators that wastes are
managed appropriately.
Hazardous waste disposal data (for wastes disposed of within the SML) are entered into
an electronic register.
Some low level radioactive waste (e.g. long lived low level radioactive sample waste) is
disposed in the TSF. The location, type and quantity of low level radioactive waste
disposed to the TSF are recorded.
Page 144
1 JULY 2010 - 30 JUNE 2011
Records of the hazardous materials disposed of within the SML were maintained by the
waste management contractor during FY11. Data collected included the type of waste,
quantity and disposal location. From these records it is estimated that approximately
7,917 tonnes of hazardous waste was disposed of within the SML in FY11.
The requirements of EPA Licence 1301 pertaining to listed waste (67-578) were complied
with in FY11.
10.7 Conclusions












Rainfall for the reporting period was 88% higher than the long term median annual
rainfall. As a result of the high rainfall and significantly higher tailings deposition, the
proportion of decant to evaporation ponds and liquor retained in tailings was
significantly higher than the previous reporting period.
The combined area of the supernatant ponds on TSF Cells 1–3 varied between 7.6ha
and 25.0ha over the reporting period with an average of 15.6ha, an increase of 84%
from the previous years average of 8.5ha.
The supernatant pond area on TSF Cell 4 varied between 22.6ha and 42.5ha over the
reporting period with an average of 30.5ha, an increase of 68% from the previous
years average of 18.2ha.
A plan to bias tailings delivery to external walls of TSF Cell 4 achieved the target of
0.3m over the reporting period.
A number of dark areas with increased moisture were identified previously around the
perimeter of the TSF and four additional areas have been identified in the current
reporting period.
A filter blanket was constructed over Location 3 on the South Wall of TSF Cell 1 to
minimise the risk of piping.
The results of the water balance indicate that the TSF has the capacity to dispose of
excess liquor by evaporation although the unaccounted liquor may also include
seepage from beach areas. Seepage from supernatant liquor ponds was estimated at
3% of liquor output.
Evaporation Pond 2 was recommissioned in November 2010, following problems with
the wave barriers in the previous reporting period.
The sewage ponds at Olympic Dam Village were managed according to the document
‘Desalination Plant Reticulation Technician Task Guide’ and EPA licence 3054.
It is estimated that approximately 35,922m3 (loose fill) of general waste was
transported to the Waste Management Centre in FY11.
Approximately 787m3 of paper and cardboard waste was collected for recycling in
FY11.
It is estimated that approximately 7,917 tonnes of hazardous waste was disposed of
within the SML in FY11.
Page 145
1 JULY 2010 - 30 JUNE 2011
11 REFERENCES
ANZECC 2000, ‘Australian and New Zealand Guidelines for Fresh and Marine Water
Quality’, Australian and New Zealand Environment and Conservation Council and
Agriculture and Resource Management Council of Australia and New Zealand, Paper
No. 4, Volumes 1-3 (Chapters 1-9).
Baillie, J and Goombridge B 1996, ‘1996 IUCN Red List of Threatened Animals’. IUCN,
Gland, Switzerland.
BHP Billiton Olympic Dam 2009, ‘Site Water Control Management Plan’, Olympic Dam
Document No. 19245.
BHP Billiton Olympic Dam 2010a, ‘Weed Management Strategy – Roxby Downs and
Andamooka Region’, unpublished BHP Billiton Olympic Dam.
BHP Billiton Olympic Dam 2010b, ‘Environmental Management Program FY11 – FY13’,
Olympic Dam Document No. 49329.
BHP Billiton Olympic Dam 2010c, ‘Monitoring Program – Groundwater FY11’, Olympic
Dam Document No. 2791.
BHP Billiton Olympic Dam 2010d, ‘Monitoring Program – Great Artesian Basin (GAB)
FY11, Olympic Dam Document No. 2789.
BHP Billiton Olympic Dam 2010e, ‘Environmental management and monitoring report, 1
July 2009 to 30 June 2010’, unpublished report for BHP Billiton Olympic Dam, report
no..ODENV041.
BHP Billiton Olympic Dam 2010f, ‘Tailings Retention System Technician Daily Routine’,
Olympic Dam Document No. 4280.
BHP Billiton Olympic Dam 2010g, ‘Tailings Management Plan’, Olympic Dam Quality
Document No. 80791.
BHP Billiton Olympic Dam 2011a, ‘BHP Billiton Olympic Dam - Great Artesian Basin
Wellfields Report 1 July 2010 to 30 June 2011’, unpublished BHP Billiton Olympic
Dam Report No. ODENV049.
BHP Billiton Olympic Dam 2011b, ‘Desalination Plant Reticulation Technician Task
Guide’, Olympic Dam Document No. 77985.
Crouch, P, Green, S and Worby, M 2003, ‘Radiation doses to members of the public
from the Olympic Dam Operation’, Presented at the Annual Conference of the
Australian Radiation Protection Society, October 2003, Hobart.
DEH, 2006, ‘Threatened species and ecological
Environment and Heritage, South Australia.
communities’,
Department
of
Environment Protection (Air Quality) Policy, 1994.
Fatchen Environmental. 2005. An assessment of WMC (Olympic Dam Corporation)
emissions impact on the flora of the special mining lease and surrounds [2004]. Report
for WMC (Olympic Dam Corporation) Pty Ltd. Mt Barker, SA: Fatchen Environmental
Pty Ltd.
Griffin, G.F. and Dunlop, S.R. 2006, ‘Impact of Emissions from the Olympic Dam Mine
Operation on the Flora and Soil of the Special Mining Lease.’, unpublished report to
BHP Billiton, Datasticians, Pillar Valley, NSW.
Page 146
REFERENCES
1 JULY 2010 - 30 JUNE 2011
Griffin, G.F. and Dunlop, S.R. 2007a, ‘Emissions dispersal patterns and impacts on soils
and vegetation in the Olympic Dam operation area.’, unpublished report to BHP
Billiton, Datasticians, Pillar Valley, NSW.
Griffin, G.F. and Dunlop, S.R. 2010a, ‘Impact of Emissions from the Olympic Dam Mine
Griffin, G.F. and Dunlop, S.R. 2010b, ‘Long-term changes in the composition of
perennial vegetation in response to emissions from the Olympic Dam operation’,
unpublished report to BHP Billiton, Datasticians, Pillar Valley, NSW.
Kershaw, KA and Looney, JHH 1985, ‘Quantitative and Dynamic Plant Ecology (3rd
Ed)’, Edward Arnold, London.
Kinhill Engineers 1997, ‘Olympic Dam Expansion Project: Environmental Impact
Statement’, Kinhill Engineers Pty Ltd, Adelaide.
National Greenhouse and Energy Reporting Act 2007.
National Greenhouse Gas and Energy Reporting Regulations 2008.
National Parks and Wildlife (SA) Act 1972.
Natural Resources Management Act 2004.
Niejalke, DP and Lamb, K 2002, ‘Can remote sensing monitor GAB spring impacts? A
progress update’, conference paper presented to the Mound Spring Researchers
Forum, Toowoomba, March 2002.
Ponder, WF 1986, ‘Mound spring snails of the Great Artesian Basin’, in Limnology in
Australia, Eds DeDecker P and Williams WD, CSIRO Australia, Melbourne.
Ponder, WF, Hershler, R, and Jenkins, B 1989, ‘An endemic radiation of Hydrobiid
Snails from artesian springs in northern South Australia: their taxonomy, physiology,
distribution and anatomy’, Malacologia 31(1): 1-140.
Read, JL 1998, ‘Are geckos useful bioindicators of air pollution?’, Oecologia 114: 180187.
Read, JL, Kovac, K and Fatchen, TJ 2005, ‘Biohyets: a holistic method of demonstrating
the extent and severity of environmental impacts’, Journal of Environmental
Management 77: 157-164.
Read, JL, Reid, N and Venables, WN 2000, ‘Which bird species are useful indicators of
mining and grazing impacts in arid South Australia?’, Environmental Management
26(2): 215-232.
Read, JL and Tyler MJ 1990, ‘The nature and incidence of post-axial, skeletal
abnormalities in the frog Neobatrachus centralis Parker at Olympic Dam, South
Australia’, Transactions of the Royal Society of South Australia 114(4): 213-217.
Roxby Downs (Indenture Ratification) Act 1982.
REFERENCES
Page 147
1 JULY 2010 - 30 JUNE 2011
Tyre, AJ and Possingham, HP 2001, ‘Risk management for ecologically sustainable
development: predicting extinction and recolonisation in the mound springs of SA –
Final Report’, unpublished report for Olympic Dam and the University of Queensland.
United Nations. 1998. Kyoto Protocol to the United Nation Framework Convention on
Climate Change. Kyoto, United Nations.
Williams, AF and Holmes, JW 1978, ‘A novel method of estimating the discharge of
water from mound springs of the Great Artesian Basin, Australia’, Journal of Hydrology
38: 263-272.
Page 148
REFERENCES
1 JULY 2010 - 30 JUNE 2011
12 GLOSSARY OF TERMS
ADU
Ammonium diuranate, commonly referred to as Yellowcake.
AHD
Australian Height Datum, a measure of elevation referenced from
approximate sea level.
Aquifer
Porous water bearing formation of permeable rock, sand, or
gravel capable of yielding significant quantities of water.
Bq
Bequerel, a unit of radioactive decay.
CEM
Continuous emissions monitoring.
Ca
Calcium.
CAF
Cemented aggregate fill.
Closure
Permanent cessation of operations at a mine or mineral
processing site after completion of the decommissioning process,
signified by tenement relinquishment.
Cu
Copper.
DCF
Dose conversion factor.
Decommissioning
Activities carried out prior to closure of the site (as operating
costs) which include flushing of lines, depressurisation of systems
and vessels and removal of hazardous materials (excluding oils
and greases) and radioactive sources unless noted otherwise in
the site closure plan.
Domestic Water
Use
Water used in the town of Roxby Downs or Olympic Dam Village.
EC
Electrical conductivity.
EDE
Effective dose equivalents.
EIHCP
Environmental / Indigenous Heritage Clearance Permit.
EPMP
Environmental Protection and Management Program. Describes
the environmental management and monitoring activities
undertaken by BHP Billiton Olympic Dam for the purpose of
quantifying any change in the extent or significance of its impacts,
assessing the performance of control measures employed to limit
impacts, and/or to meet legal and other obligations.
EMS
Environmental Management System. The part of an
organisation’s management system used to develop and
implement its environmental policy and manage its environmental
aspects (Standards Australia / Standards New Zealand 2004).
Note: A management system is a set of interrelated elements
used to establish policy and objectives and to achieve those
objectives. A management system includes organisational
structure,
planning
activities,
responsibilities,
practices,
procedures, processes and resources.
Environmental
Aspect
GLOSSARY OF TERMS
An element of the organisation’s activities or products or services
that can interact with the environment (Standards Australia /
Standards New Zealand 2004).
Page 149
1 JULY 2010 - 30 JUNE 2011
Environmental
Impact
Any change to the environment, whether adverse or beneficial
wholly or partially resulting from an organisation’s environmental
aspects (Standards Australia / Standards New Zealand 2004).
EPA
Environment Protection Authority.
Evaporation Pond
A containment pond to hold liquid wastes to assist with disposal of
liquor via evaporation.
Fe
Iron.
GAB
Great Artesian Basin.
HDPE
High density polyethylene.
HVAS
High Volume Air Sampler(s)
ICRP
International Commission on Radiological Protection.
Industrial
use
Water Water used in mining or mineral processing operations and
excluding domestic water use.
Mn
Manganese.
MP
Monitoring Program. A document which describes the
environmental monitoring activities undertaken by BHP Billiton
Olympic Dam for the purpose of quantifying any change in the
extent or significance of its impacts, assessing the performance of
the control measures employed to limit its impacts, and/or to meet
its legal and other obligations.
NaCI
Sodium chloride (salt).
Na2S
Sodium sulfide.
NEPM
National Environment Protection Measure.
3
Nm
Normal metres cubed, referring to volume at a standard
temperature and pressure.
NOx
Oxides of nitrogen.
OD
Olympic Dam.
ODV
Olympic Dam Village monitoring site.
PAH
Poly aromatic hydrocarbons.
Pb
Lead.
210
An isotope of lead, having mass number 82 and half-life 22.3
years.
pH
A measure of acidity and alkalinity.
PM10
Particulate matter with an diameter less than or equal to 10 µm
Pb
Po
Polonium.
210
An isotope of polonium, having mass number 84 and half-life
138.38 days.
Ra
Radium.
226
An isotope of radium, having mass number 88 and half-life 1599
years.
Po
Ra
Page 150
GLOSSARY OF TERMS
1 JULY 2010 - 30 JUNE 2011
Radon
Chemically inert radioactive gaseous element formed from the
decay of uranium.
RDS
Roxby Downs Township monitoring site.
Rehabilitation
The reclamation or repair, as far as practicable, of a facility to an
appropriate or agreed state as required by law, or company selfregulation.
Rn
Radon.
222
An isotope of radon, having mass number of 86 and half-life
3.8235 days.
Significant aspect
An environmental aspect that has or can have a significant
environmental impact. Significance is determined by risk
assessment.
SML
Special Mining Lease.
SOx
Oxides of sulphur.
SO2
Sulphur dioxide.
SO3
Sulphur trioxide.
SO4
Sulphate.
SWL
Standing water level.
TDS
Total dissolved solids.
Th
Thorium.
230
An isotope of thorium, having mass number 90 and half-life 7.54 ×
104 years.
Total Industrial
Water Use
Total water used including high quality (GAB) water and water
recovered from other sources including abstraction of local saline
water.
TRS
Tailings Retention System. Incorporates all elements of the
tailings delivery, deposition and storage system and elements
associated with the collection and disposal or return of tailings
liquor. The TRS includes the Tailings Storage Facility (TSF),
Evaporation Ponds and Pipe Corridors including tailings delivery
pipelines and liquor pipelines.
TSF
Tailings Storage Facility. Incorporates the tailings deposition and
storage system, which currently comprises four storage cells.
TSP
Total Suspended Particulates (dust)
U
Uranium.
Rn
Th
238
The most common isotope of uranium, having mass number 238
and half-life 4.46 × 109 years.
UOC
Uranium oxide concentrate, final uranium product at BHP Billiton
Olympic Dam, consisting of 99% U3O8.
VOC
Volatile organic compound.
U
GLOSSARY OF TERMS
Page 151
1 JULY 2010 - 30 JUNE 2011
13 APPENDIX 1: SUMMARY OF EXTERNALLY
REPORTABLE SPILLS
Event
Cause
Impact
01/09/10
Approx 86m3 of acidic
liquor was released into
the tailings pipeline
corridor along the east
side of TSF Cell 2/3.
Butt weld failure on a
Evaporation Pond Return
Liquor (EPRL) Line.
There was no occupational
health and safety or
environmental
impacts.
The spilt material was
recovered and disposed of
in the Tailings Storage
Facility.
13/02/11
Approx
5-10g
of
concentrated uranium;
ammonia
diuranate
(ADU) outside of bund
in the Precipitation area.
Small clumps of ADU
dislodged and deposited
outside of the bund during
maintenance
activities
which involved replacing
structural unsound steel
and cladding.
environmental
impacts.
Facility.
15/02/11
Approx 120 m3 of acidic
liquor was released into
the tailings pipeline
corridor west of Solvent
Extraction.
Butt weld failure on a
Evaporation Pond Return
Liquor (EPRL) Line.
environmental
impacts.
Facility.
01/05/11
Approx
180m3
of
radioactive
process
material was released
outside bund area at
Tailings Disposal.
Sleeve failure on valve
UV1309 line 2 resulted in
acidic tailings slurry being
released outside of bund
area.
environmental
impacts.
Facility.
Date
reported
Page 152
APPENDIX 1: SUMMARY OF EXTERNALLY REPORTABLE SPILLS
1 JULY 2010 - 30 JUNE 2011
14 APPENDIX 2: METEOROLOGICAL DATA
As shown in Figure 14-1, a total of 278.4mm of rainfall was measured for the reporting
period. This is well above the long-term (1931 – present) median annual rainfall of
136.3mm.
120
100
Rainfall (mm)
80
60
40
20
Rainfall
Jun-2011
May-2011
Apr-2011
Mar-2011
Feb-2011
Jan-2011
Dec-2010
Nov-2010
Oct-2010
Sep-2010
Aug-2010
Jul-2010
0
Long Term Monthly Median
Figure 14-1: Annual rainfall FY11
Figure 14-3 illustrates the annual wind rose for the reporting period. Wind speed and
direction data recorded from the BOM weather station has been used to indicate the wind
vector.
Due to the use of new Grapher software to compile the wind rose for FY10, incorrect
settings were used and as a result the wind rose produced was not accurate. This has
since been corrected and a new wind rose produced for FY10. Figure 14-3 illustrates the
annual wind rose for FY10. Wind speed and direction data recorded from the BOM
weather station has been used to indicate the wind vector.
APPENDIX 2: METEOROLOGICAL DATA
Page 153
1 JULY 2010 - 30 JUNE 2011
North
0
315
45
90
270
0%
4%
8%
12%
16%
225
135
180

20%
Wind Speed (knots)
<=5
>5 - 10
>10 - 15
>15
Note: wind direction indicated is from the outside of the circle toward the centre.
Figure 14-2: Wind rose, FY11
Page 154
1 JULY 2010 - 30 JUNE 2011
North
0
315
45
90
270
0%
4%
8%
12%
16%
225
135
180

20%
Wind Speed (knots)
<=5
>5 - 10
>10 - 15
>15
Note: wind direction indicated is from the outside of the circle toward the centre.
Figure 14-3: Corrected Wind rose, FY10
Page 155
1 JULY 2010 - 30 JUNE 2011
15 APPENDIX 4: CONSULTANTS UTILISED
BETWEEN 1 July 2010 – 30 June 2011
Air Emissions Sampling

Axiom Air (Adelaide, SA)
Aerial Photography

Fugro Spatial Solutions (Eight Mile Plains, QLD)
EMS

SGS Australia Pty Ltd, Systems and Services Certification (Adelaide, SA)
Energy and Greenhouse Gas Reporting


GHD Consulting (Sydney, NSW)
Balance Energy (Adelaide, SA)
Flora

Datasticians (Pillar Valley, NSW)
GAB


Land Use Consultants (Clare, SA)
Australia Water Environments
Tailings Management





Knight Piesold (Sydney, NSW)
Coffey Geosciences Pty Ltd
GHD Consulting (Sydney, NSW)
Sinclair Knight Merz (SKM) (Melbourne, VIC)
Exact Mining Services (Wayville, SA)
Page 156
APPENDIX 4: CONSULTANTS UTILISED BETWEEN 1 July 2010 – 30 June 2011

Environmental Management and Monitoring Report 1 July

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