GREAT ARTESIAN BASIN WELLFIELDS REPORT 1 JULY 2009 - 30 JUNE 2010 Report No. ODENV 046
Uranium
Olympic Dam
Olympic Dam BHP Billiton Limited Uranium ABN 99 007 835 761
A member of the BHP Billiton Olympic Dam Corporation Pty Ltd, which is headquartered in Australia Registered Office: Rialto Towers Level 29, 525 Collins St, Melbourne, Victoria 3000, Australia ABN 49 004 028 077
OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT 1 JULY 2009 - 30 JUNE 2010 The Hon. Paul Holloway MLC Minister for Mineral Resources Development 9th Floor – Terrace Towers 178 North Terrace ADELAIDE SA 5000
EXTERNAL DISTRIBUTION
Department of Primary Industries Chief Inspector of Mines 1 CD copy and Resources (SA)
Department For Environment And CE Dept for Environment and 1 CD copy Natural Resources (SA) Natural Resources Principle Scientific Officer – 1 CD copy Pastoral Program
Environment Protection Authority CE Environment Protection 1 CD copy (SA) Authority EPA Licence Coordinator 1 CD copy Manager Mining & Environment 1 CD copy Group Radiation Protection Branch
Department For Water (SA) CE Dept for Water 1 CD copy Senior Hydrogeologist 1 CD copy
Great Artesian Basin Coordinating The Chair 1 CD copy Committee
South Australian Arid Lands Natural The Chair 1 CD copy Resources Management Board
INTERNAL DISTRIBUTION
BHP Billiton Adelaide President Uranium 1 CD copy Vice President – External Affairs 1 CD copy Corporate Lawyer 1 CD copy Sustainability Manager 1 CD copy
BHP Billiton Olympic Dam Asset President Olympic Dam 1 CD copy General Manager Mine 1 CD copy General Manager Surface 1 CD copy General Manager Services 1 CD copy Head of HSEC 1 CD copy Manager Environment and Radiation 1 CD copy Environmental Section Library 2 hard copies 2 CD copies Records Centre 2 hard copies 1 CD copy
1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table of Contents
1 EXECUTIVE SUMMARY...... 6 2 INTRODUCTION ...... 7 2.1 Scope ...... 7 2.2 Background ...... 7 2.3 Legal Criteria ...... 11 3 MONITORING PROGRAM...... 12 3.1 Monitoring Sites and Schedules...... 12 3.2 Parameters and Measurements ...... 14 4 ABSTRACTION ...... 16 4.1 Development History ...... 16 4.2 Olympic Dam Abstraction during the Current Review Period...... 16 4.3 Pastoral Abstraction ...... 16 4.4 Total Abstraction...... 17 5 WELLFIELD A AREA AQUIFER RESPONSE ...... 23 5.1 Monitoring Program Requirements...... 23 5.2 Wellfield A Sub-Basin...... 23 5.3 North east Sub-Basin ...... 31 5.4 Hermit Hill...... 31 5.5 Boundary of Wellfield A Designated Area ...... 31 6 WELLFIELD B AREA AQUIFER RESPONSE ...... 36 6.1 Monitoring Program Requirements...... 36 6.2 Overall Response and Boundary of Wellfield B Designated Area...... 37 6.3 Northern Observation Bores...... 43 6.4 South east Observation Bores...... 43 6.5 Eastern Springs Zone...... 43 6.6 Crows Nest Area ...... 50 6.7 Key Pastoral Bores...... 50 6.8 Drawdown Impacts on Pastoral Bore Operation ...... 53 7 GAB SPRING FLOW ...... 55 7.1 Monitoring Program Requirements...... 55 7.2 Results...... 55 8 GROUNDWATER CHEMISTRY ...... 57 8.1 Monitoring Program Requirements...... 57 8.2 Results...... 57 9 GAB WATER USE EFFICIENCY...... 60 9.1 Monitoring Program Requirements...... 60 9.2 Results...... 60
EXECUTIVE SUMMARY PAGE 1 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT 10 RESOURCE SUSTAINABILITY AND MANAGEMENT ...... 61 10.1 Historical Perspective ...... 61 10.2 Further Exploration and Development ...... 61 10.3 Future Perspective...... 61 11 WELLFIELDS INVESTIGATIONS AND TECHNICAL WORKS PROGRAM ...... 62 11.1 Installation of Four New Monitoring Bores...... 63 11.2 Increased Monitoring of Jackboot Bore and the New Monitoring Bores...... 64 11.3 Undertake a Review of Existing Structural Geology and Seismic Information...... 66 11.4 Conduct New Seismic Work (if required)...... 67 11.5 Enhance the Existing Hydrogeological Model ...... 67 11.6 Review the Reference Pressures for all Compliance Monitoring Wells...... 67 11.7 Identify alternative monitoring point(s) for Wellfield A and B or recommend new drawdown action triggers for existing monitoring points ...... 71 11.8 Develop a proposal for ongoing sustainable management of BHP Billiton’s extractions from the GAB...... 71 11.9 Discussion ...... 71 11.10 Summary and Conclusions...... 72 12 RECOMMENDATIONS...... 73 13 REFERENCES ...... 74 14 APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10.. 76 15 APPENDIX 2: CALIBRATION CERTIFICATES FOR DRUCK PRESSURE TRANSDUCERS...... 84 16 APPENDIX 3: SUMMARY OF SPRING FLOW DATA FY10 ...... 86 17 APPENDIX 4: HISTORICAL SPRING FLOW RATES ...... 88 18 APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10 ...... 103 19 APPENDIX 6: CONDUCTIVITY TREND DATA ...... 110 20 APPENDIX 6: TEN YEAR FORWARD SCHEDULE FOR GAB ABSTRACTION...... 118 21 APPENDIX 7: NOMENCLATURE AND CODING FOR GAB SPRINGS...... 119 21.1 Spring Nomenclature and Coding...... 119 21.2 Monitored Springs...... 119 22 APPENDIX 8: MINISTER’S PROGRAM OF TECHNICAL WORKS ... 121
PAGE 2 EXECUTIVE SUMMARY 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
List of Figures
Figure 2-1: Wellfield A location map...... 8 Figure 2-2: Wellfield B location map...... 9 Figure 2-3: Monitored spring groups showing hydrogeological domains ...... 10 Figure 4-1: Historical abstraction from Wellfields A and B – 3 month moving average...... 22 Figure 4-2: Total abstraction from the Wellfields area – 3 month moving average...... 22 Figure 5-1: Wellfield A total drawdown contours for FY10, contour interval 2m...... 27 Figure 5-2: Wellfield A Sub-basin – groundwater head...... 29 Figure 5-3: Wellfield A and North-east Sub-basin – spring flow rates...... 30 Figure 5-4: Wellfield A Compliance Bores – GAB8/HH2...... 32 Figure 5-5: Wellfield A Compliance Bores - Jackboot...... 32 Figure 5-6: Wellfield A North-east Sub-basin – groundwater head ...... 33 Figure 5-7: Hermit Hill area – groundwater head and spring flow rates ...... 34 Figure 5-8: Wellfield A – SWL boundary aquifer pressure ...... 35 Figure 6-1: Wellfield B total drawdown contours for FY10, contour interval 2m...... 41 Figure 6-2: Wellfield B Compliance Bores – D2 and S3...... 44 Figure 6-3: Wellfield B Compliance Bores – S1 and Tarkanina #2 ...... 44 Figure 6-4: Wellfield B northern monitoring bore pressures...... 46 Figure 6-5: Wellfield B southern monitoring bore pressures ...... 47 Figure 6-6: Wellfield B area spring flow rates...... 48 Figure 6-7: Wellfield B Crows Nest area monitoring bore pressures ...... 51 Figure 6-8: Wellfield B pastoral bore pressure...... 52 Figure 6-9: Monitoring trends, Mundowdna Station pressurised bores...... 54 Figure 6-10: Monitoring trends, Mundowdna Station sub-artesian bores and springs ...... 54 Figure 8-1: Frequency distribution of conductivity trends for the wellfields area...... 59 Figure 11-1: Recommended Bores for the Delineation of Drawdown ...... 69 Figure 17-1: Spring flow rate - CBC001 ...... 88 Figure 17-2: Spring flow rate - CBC002 ...... 88 Figure 17-3: Spring flow rate - CBC013 ...... 89 Figure 17-4: Spring flow rate – HBO004 ...... 89 Figure 17-5: Spring flow rate - HBO007...... 89 Figure 17-6: Spring flow rate - HBO011...... 90 Figure 17-7: Spring flow rate - HBS004 ...... 90 Figure 17-8: Spring flow rate - HDB004 ...... 90 Figure 17-9: Spring flow rate - HDB005 ...... 91 Figure 17-10: Spring flow rate – HHS028 ...... 91 Figure 17-11: Spring flow rate – HHS035 ...... 91 Figure 17-12: Spring flow rate – HHS101 ...... 92 Figure 17-13: Spring flow rate – HHS125 ...... 92
EXECUTIVE SUMMARY PAGE 3 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Figure 17-14: Spring flow rate – HHS137...... 92 Figure 17-15: Spring flow rate – HHS170...... 93 Figure 17-16: Spring flow rate – HOF004...... 93 Figure 17-17: Spring flow rate – HOF033...... 93 Figure 17-18: Spring flow rate – HOF081...... 94 Figure 17-19: Spring flow rate – HOF094...... 94 Figure 17-20: Spring flow rate – HOF096...... 94 Figure 17-21: Spring flow rate – HOW009 ...... 95 Figure 17-22: Spring flow rate – HOW015 ...... 95 Figure 17-23: Spring flow rate – HOW025 ...... 95 Figure 17-24: Spring flow rate – HSS011...... 96 Figure 17-25: Spring flow rate – HSS012...... 96 Figure 17-26: Spring flow rate – HSS024...... 96 Figure 17-27: Spring flow rate – HWF003 ...... 97 Figure 17-28: Spring flow rate – HWF048 ...... 97 Figure 17-29: Spring flow rate – LES001 ...... 97 Figure 17-30: Spring flow rate – LFE001...... 98 Figure 17-31: Spring flow rate – LFE006...... 98 Figure 17-32: Spring flow rate – LGS002 ...... 98 Figure 17-33: Spring flow rate – LGS004 ...... 99 Figure 17-34: Spring flow rate – LMS004B ...... 99 Figure 17-35: Spring flow rate – WDS001...... 99 Figure 17-36: Spring flow rate – WDS042...... 100 Figure 17-37: Spring flow rate – WDS052...... 100 Figure 17-38: Spring flow rate – WWS001 ...... 100 Figure 17-39: Spring flow rate – WWS002 ...... 101 Figure 17-40: Spring flow rate – WWS004 ...... 101 Figure 17-41: Spring flow rate – WWS013 ...... 101 Figure 19-1: Conductivity trend for Bopeechee HBO007 ...... 110 Figure 19-2: Conductivity trend for Clayton Dam ...... 111 Figure 19-3: Conductivity trend for GAB8...... 111 Figure 19-4: Conductivity trend for GAB10...... 112 Figure 19-5: Conductivity trend for GAB15...... 112 Figure 19-6: Conductivity trend for GAB15A ...... 113 Figure 19-7: Conductivity trend for Kopperamanna...... 113 Figure 19-8: Conductivity trend for New Years Gift ...... 114 Figure 19-9: Conductivity trend for Old Finniss HOF033...... 114 Figure 19-10: Conductivity trend for Old Finniss HOF094...... 115 Figure 19-11: Conductivity trend for Old Woman HOW015 ...... 115 Figure 19-12: Conductivity trend for Sulphuric HSS012...... 116 Figure 19-13: Conductivity trend for West Finniss HWF048 ...... 116 Figure 19-14: Conductivity trend for Wirringinna MWI001...... 117
PAGE 4 EXECUTIVE SUMMARY 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
List of Tables
Table 3-1: Wellfield A – summary of key monitoring sites ...... 13 Table 3-2: Wellfield B – summary of key monitoring sites ...... 14 Table 4-1: Wellfields average annual daily abstraction rate...... 18 Table 4-2: Monthly average abstraction rate (ML/d), FY10...... 19 Table 4-3: Abstraction rates measured and estimated at pastoral bores in the wellfields area, June 2010 ...... 21 Table 5-1: Wellfield A – summary of drawdown and recovery ...... 25 Table 6-1: Wellfield B – summary of drawdown to June 2010 ...... 39 Table 6-2: Drawdown at selected pastoral bores in the wellfields area to June 2010...... 40 Table 11-1: BHP Billiton Reports Relevant to the Technical Works Program...... 63 Table 20-1: Monitored springs in the vicinity of Lake Eyre South ...... 120
EXECUTIVE SUMMARY PAGE 5 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
1 EXECUTIVE SUMMARY
The Wellfields Report is prepared annually in accordance with the conditions of the Roxby Downs (Indenture Ratification) Act 1982, and the Olympic Dam and Stuart Shelf Indenture (the Indenture) ratified by that Act. This report presents data that relates to the operation of the BHP Billiton Olympic Dam Great Artesian Basin water supply wellfields for the period 1 July 2009 to 30 June 2010. Abstraction rates during FY10 were significantly lower than previous years due to the failure of the Clark Shaft in October 2009. The overall average was 21.9ML/d comprising 2.3ML/d from Wellfield A and 19.6ML/d from Wellfield B (Table 4-2, Figure 4-1 and Figure 4-2), representing a decrease of 50% for Wellfield A and 30% for Wellfield B over the previous period averages. Total estimated pastoral abstraction from bores in the immediate wellfield area at the end of June 2010 was 14.8ML/d, compared to 18.4ML/d for the same period in 2009. In the Wellfield A area, environmental flow rates at GAB springs remain relatively consistent and in line with historical averages. Overall drawdown values decreased over the period – thought to be due in part to the reduction in abstraction from Wellfield A and also to the absence of elevation corrections in previous data. Spring flow rates for Wellfield B were stable throughout the reporting period and show no new trends. Maximum average drawdown at a corner of the Wellfield B designated area was 3.6m (35.2kPa) at D2. Average drawdown at Jackboot Bore decreased by 1.6m (15.2kPa) to reach a total of 2.5m based on the 641kPa Wellfield B reference pressure. The major decrease in apparent drawdown at Jackboot is the result of a reduction, and eventual elimination of antecedent pastoral flow following BHP Billiton’s purchase of the Lake Eyre pastoral lease in June 2009. For pastoral bores the maximum wellhead pressure loss of 106kPa was at Lake Harry. Maximum pressure loss as a percentage of baseline pressure was 34% at Marion, again as in the last reporting period. In general drawdown and percentage pressure loss at pastoral bores remains less than the predicted long-term impact as presented in the Environmental Impact Statement (EIS, Kinhill Engineers, 1997). Additional monitoring of drawdown impacts in the Mundowdna area to the south east of Wellfield B continued. Interpreted drawdown contours for Wellfield B show the drawdown pattern generally conforms to that presented in the EIS. Drawdown to the south west of Wellfield B remains substantially less than EIS predictions, whilst drawdown remains greater than predicted on the south east boundary of the designated area, with a strong drawdown gradient existing near the southern corner (S3) where the aquifer is known to be discontinuous. Analysis of spring and bore conductivity data indicated no major conclusions or changes to previously identified trends. In FY10 BHP Billiton completed four new monitoring bores (MB5 – 8) to enhance the existing groundwater monitoring infrastructure associated with groundwater abstraction from Wellfield B in the GAB: • MB5 replaced the dysfunctional MB4 monitoring bore. • MB6 is to monitor head near the western GAB springs. • MB7 and MB8 are to monitor drawdown from Wellfield B. All four bores have already provided new information on the structure and hydraulic characteristics of the GAB aquifer. Measurements in the new bores have improved groundwater monitoring and better defined the drawdown pattern to the west of Wellfield B.
PAGE 6 EXECUTIVE SUMMARY 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
2 INTRODUCTION
2.1 Scope This report presents data relating to the operation of the BHP Billiton Olympic Dam Great Artesian Basin water supply wellfields for the period 1 July 2009 to 30 June 2010. Report objectives are to: • Document the results of the monitoring program. • Evaluate drawdown response of the aquifer to BHP Billiton Olympic Dam abstraction, particularly within the designated area of both wellfields. • Assess the impacts of abstraction on groundwater chemistry. • Compare actual impacts to predictions in the Environmental Impact Statement (EIS) (Kinhill Engineers, 1997). • Meet the requirements of Clause 13 of the Olympic Dam and Stuart Shelf Indenture (the Indenture).
2.2 Background Water used at BHP Billiton Olympic Dam and Roxby Downs Township is pumped from two wellfields located within the Great Artesian Basin (GAB) (Error! Reference source not found. and Figure 2-2). Wellfield A is located 100km north of the operation at the south west margin of the GAB. Wellfield B is located an additional 80km to the north east of Wellfield A, further into the basin. The GAB is one of the world’s largest groundwater reservoirs, covering a total area in excess of 1.7 million km2, of which approximately 350,000km2 lies in South Australia. Aquifers are recharged by rainfall and stream flow in outcrop areas on the western flanks of the Great Dividing Range (Qld and NSW) and to a lesser extent on the north west basin margin (Qld and NT). During 2000 the Bureau of Rural Sciences published a revised numerical assessment of the groundwater flow characteristics of the GAB (Welsh, 2000). The steady-state water balance was calculated at 3.21GL/d. This balance is in close agreement with the results of the previous major basin-wide groundwater flow model that indicated a recharge rate of 3.02GL/d (Habermehl, 1980). The basin-wide water balance calculations have indicated that GAB inflow into South Australia is about 450ML/d (ABARE et al., 1996). Major components of discharge are estimated to include pastoral artesian bores (30%) and GAB springs (15%), with about 50% discharged through confining layers by diffuse upward leakage to shallow saline aquifers and the atmosphere (ABARE et al., 1996). Average BHP Billiton Olympic Dam abstraction over the past five years represents approximately 7% of the estimated total GAB inflow into South Australia. GAB springs in South Australia have particular cultural and ecological significance and several GAB springs are located in the region of the BHP Billiton Olympic Dam wellfields (Figure 2-3). BHP Billiton Olympic Dam has planned and managed the abstraction of groundwater to minimise impacts on GAB springs. The local hydrogeology has been previously described by WMC during investigations for the establishment of Wellfield B (WMC, 1995). Wellfield A is located at the margin of the GAB, where there is relatively complicated basin architecture and strong influence of aquifer boundary effects. Separate hydrogeological domains with distinctively different responses to the Wellfield A abstraction occur. The zonation is strongly influenced by the depositional distribution of the aquifer sediments and fault offsetting of the aquifer over subsequent geological history. Wellfield B is located further into the basin where aquifer zonation is less marked. The aquifer at Wellfield B is more radially
INTRODUCTION PAGE 7 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT symmetrical and thicker, meaning fault offsets have less impact on aquifer response to abstraction.
Figure 2-1: Wellfield A location map
PAGE 8 INTRODUCTION 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Figure 2-2: Wellfield B location map
INTRODUCTION PAGE 9 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Figure 2-3: Monitored spring groups showing hydrogeological domains Detailed description of the physical environment of the wellfields is contained in the Draft EIS (Kinhill-Stearns Roger, 1982) and the Survey and Assessment Report (Kinhill Engineers, 1995). Wellfield construction details are contained in ‘Wellfield A Construction’ (AGC, 1987) and ‘Borefield B Development’ (WMC, 1997) and related documents.
PAGE 10 INTRODUCTION 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Place names and particularly spelling for some pastoral bores in the wellfields area can vary between publications. Place names and spellings used in this report are taken from the online Gazetteer of Australia (Geoscience Australia, 2007).
2.3 Legal Criteria This report is produced in accordance with the conditions of the Roxby Downs (Indenture Ratification) Act 1982, and the Olympic Dam and Stuart Shelf Indenture (the Indenture) ratified by that Act. The Special Water Licences (SWL) for each wellfield are granted under the Indenture. The SWL – Wellfield A was granted in May 1986. The SWL – Wellfield B was granted in November 1995. The Indenture requires a monitoring system covering the following items: • Total abstraction and individual well abstraction on a monthly basis. • Water pressure and levels in monitoring and production wells and at the boundary of designated areas. • Water quality at monitoring and production wells on a quarterly basis. The Indenture states that an annual hydrogeological report shall be prepared to define the following: • Aquifer response to wellfields operation. • Ability of the resource to maintain the supply. • Strategy for future abstraction and management. • Requirements for further exploration or development.
INTRODUCTION PAGE 11 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
3 MONITORING PROGRAM
A full and detailed description of monitoring sites, frequency, priorities and methodologies is maintained in the Monitoring Program – Great Artesian Basin (GAB) FY10 (BHP Billiton, 2009a).
3.1 Monitoring Sites and Schedules A summary of the key wellfield monitoring sites is provided in Table 3-1 and Table 3-2, with sites shown in Error! Reference source not found., Figure 2-2 and Figure 2-3. For Wellfield A, sites are classified into zones that represent separate hydrogeological domains with different aquifer responses. The frequency of pressure readings at Wellfield A monitoring bores was reduced from monthly to quarterly from February 1999, in accordance with the government approved monitoring program (BHP Billiton, 2008a). The reduced frequency was justified by the relatively gradual changes in pressure that now occur in the area, following the period of rapid recovery after reduced abstraction from late 1996. Monthly environmental flow monitoring of GAB springs was reduced to biannual measurement during 2002, as remote sensing techniques are now used to generate wetland area data in support of spring flow measurements. Details of this technique can be found in the Monitoring Program – Flora FY10 (BHP Billiton, 2009b). For an explanation of spring codes see Appendix 7. For Wellfield B, zones are spatial groupings not necessarily reflecting distinctly different hydrogeological domains. Monthly monitoring commenced in 1983 at WCB1 and WCB2 and annually at selected pastoral bores. These results were not reported before abstraction from Wellfield B commenced. In mid-1994 and mid-1995 monthly monitoring was expanded for the planned construction of Wellfield B. Seven observation bores (S1–S5, D2 and D3) were constructed between July and November 1996 and were monitored monthly until 2001, at which time monitoring was reduced to quarterly. Data referred to but not specifically or comprehensively covered by this report include: • Production bore pressure (of operational relevance only). • Distant, annually monitored pastoral bores where shut-in pressure is not obtained. • Biannual spring monitoring results, reported separately (Land Use Consultants 2009, 2010).
PAGE 12 MONITORING PROGRAM 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table 3-1: Wellfield A – summary of key monitoring sites
Zone Observation bores Environmental flow monitoring Regional Local Wellfield Sub-basin GAB1 GAB6A New Years Gift Bore GAB2 GAB12A Venables Bore GAB5 GAB14A Beatrice Bore GAB5A GAB15A Fred Spring LFE001 GAB13 GAB16A GAB17 GAB18A GAB21 GAB22 GAB23 MB2 North-east Sub-basin GAB7 McLachlan Spring LMS004 GAB8 Bopeechee Bore GAB10 Bopeechee Spring HBO004 GAB11 Gosse Spring LGS004 GAB19 HH2 MB1 Hermit Hill HH1 Hermit Hill Spring HHS170 HH3 Old Finniss Spring HOF096 HH4 Old Finniss Spring HOF081 Wellfield Extension GAB33 GAB30A Emerald Spring LES001 GAB31A GAB24 Northern Boundary Jackboot
MONITORING PROGRAM PAGE 13 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table 3-2: Wellfield B – summary of key monitoring sites
Zone Observation bores Environmental flow monitoring Monitoring Pastoral Northern D2 Jackboot D3 Tarkanina S5 Georgia Clayton 2 Yarra Hill Southern S1 Callanna Welcome Spring WWS002 S2 Charles Angus Welcome Spring WWS004 S3A Highway S4 Maynards WCB1 Morris Creek Peters Crows Nest OB1 OB3 OB6 WCB2
3.2 Parameters and Measurements Field monitoring (other than for environmental flow monitoring of springs) is undertaken by the BHP Billiton Olympic Dam Environment Section. Abstraction data are provided by engineering staff as summaries for the calendar month. Monitoring parameters are classified by site as follows: • Observation bores – quarterly pressure and field water quality. • Production bores – observation bore parameters plus monthly abstraction. • Environmental flow monitoring sites – biannual flow rate and field water quality. • Pastoral bores – quarterly or annual field water quality plus flow rate, flow pressure and shut-in pressure, as appropriate to particular sites. 3.2.1 Pressure Measurement Pressure measurements are taken with Druck digital read-out pressure transducers. Calibration checks have shown the gauges remain within the manufacturer’s specification of +/–5.0kPa. Both units in regular use were calibrated during the reporting period, giving a maximum reading error of 0.9kPa. Tests were conducted in accordance with Australian Standards (see Appendix 2). Pressure reduction (drawdown) is calculated from reference pressures mostly defined at the time of granting of the Special Water Licences, although subsequent variations have occurred. For shallow bores in the Wellfield A area where aquifer depths are less than 200m, pressures are reported in units of metres head above Australian Height Datum (AHD, 0m AHD approximates mean sea level). Values are obtained by converting gauge pressure to metres (kPa x 0.1023) and adding to the gauge elevation, this being an accurate approximation of true hydraulic (potentiometric) head.
PAGE 14 MONITORING PROGRAM 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
For deeper bores, significant temperature and pressure induced variations of water density exist between the aquifer and measurement point. This means that estimating true hydraulic head is more complicated (WMC, 1998) and, as a result, deep bore pressures are reported as kPa above the reference point at each site. Drawdown (reduction in hydraulic head), expressed as metres head of water, can then be calculated from the reduction in wellhead gauge pressure at all sites, using the conversion factor 0.1023. Pressure measurement of shut-in pressure (SIP) at pastoral bores and observation bores used for pastoral supplies is affected by local aquifer drawdown and water temperature and density variations. For these bores a practical reference pressure (PRP) is defined which relates to standard usage and shut-in procedures. The PRP can be related to SIPs which are not affected by local bore flow, particularly the cold reference pressure (CRP). CRP can be measured after long-term cooling and local pressure recovery at the bore (WMC, 1998). Maximum measured pressure (MMP) applies to pressure measurements using an experimentally derived procedure of optimum flow (heating) phase followed by a set recovery period. 3.2.2 Abstraction and Flow Measurement Abstraction from Wellfield A bores is monitored by individual meter readings of impeller type meters at the wellhead. Abstraction at Wellfield B is metered ultrasonically and transmitted to site via telemetry. There is a monthly reconciliation between volumes pumped from individual bores and the total received at Olympic Dam. Pastoral bore flow rates are measured with a portable ultrasonic meter or a bucket and stopwatch where possible. Environmental bore and GAB spring flow rates are measured by standard weirs, fluorometric dye injection or bucket and stopwatch. 3.2.3 Water Chemistry Field water quality parameters include temperature, pH and electrical conductivity (EC), measured using standard calibrated instruments.
MONITORING PROGRAM PAGE 15 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
4 ABSTRACTION
4.1 Development History Long-term abstraction trends (Table 4-1, Figure 4-1 and Figure 4-2) can be summarised as follows: • Abstraction from Wellfield A commenced in July 1983 and remained uniform at 1.3ML/d until December 1986. • Through 1987 and 1988 there was a gradual increase to around 10.0ML/d, associated with construction and increase of mill production to 45,000t/yr copper. • Abstraction continued at around 10.0ML/d from 1989 until 1992. • From 1992 to 1995 abstraction was about 12.0ML/d following the first optimisation at Olympic Dam and an increase in production to 66,000t/yr copper. • From 1995 to September 1996 Wellfield A abstraction was typically 14.0–16.0ML/d, following a second optimisation which saw production rise to 85,000t/yr copper. • Wellfield B came on line in October 1996, and since this time abstraction from Wellfield A has typically been at about 5.0ML/d. • Wellfield B abstraction rose continuously from 4.0ML/d in October 1996 to 12.0ML/d in June 1997, with total abstraction remaining at about 16.0ML/d. • From July 1997 to November 1998 Wellfield B abstraction was fairly stable at 11.0−14.0ML/d, with a slight overall rise in total abstraction from typical rates of 16.0ML/d to 18.0ML/d over this period. • From December 1998 to October 1999 total abstraction rose to 30.0ML/d as copper production was ramped up to the full capacity of the mine and processing plant. • For financial years 2000 to 2009 a relatively stable abstraction pattern developed. Average total abstraction over the 9 year period was 32.3ML/d, comprising 27.0ML/d from Wellfield B and 5.3ML/d from Wellfield A. Rates varied seasonally between 27–37.0ML/d, with typical rates of 3.0–6.0ML/d from Wellfield A and 22.0– 32.0ML/d from Wellfield B. Higher abstraction rates generally occur during summer months.
4.2 Olympic Dam Abstraction during the Current Review Period Abstraction rates during FY10 were affected by the failure of the main ore haulage shaft (Clark Shaft) in October 2009. The subsequent reduction in processing in the hydrometallurgical plant substantially reduced the demand for water. Recommissioning of the shaft at the end of the period saw abstraction rates return to within normal operating ranges. The overall average was 21.9ML/d comprising 2.3ML/d from Wellfield A and 19.6ML/d from Wellfield B (Table 4-2, Figure 4-1 and Figure 4-2), representing a decrease of 50% for Wellfield A and 30% for Wellfield B over the previous period averages. Monthly abstraction rates were extremely variable, ranging from 11.4–32.6ML/d, with highest total abstraction in August 2009 and the lowest in January 2010.
4.3 Pastoral Abstraction Flow rate measurement by BHP Billiton Olympic Dam (OD) and the Department for Water (DfW; previously Department of Water, Land and Biodiversity Conservation) over a number of years has shown that most pastoral bores are operated at relatively consistent flow rates. Many bores support extensive pipeline reticulation networks that require high wellhead pressures (low flow rates).
PAGE 16 ABSTRACTION 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Flow rate from 32 significant pastoral bores in the wellfields area, where variation in flow rate could produce short-term impacts on regional monitoring, is estimated or measured at the end of the review period (Table 4-3). Note that pastoral flow rates are taken from direct flow rate measurements as well as flow rate/flow pressure relationships. This data is reviewed and revised annually in the light of most recent data, resulting in changes to the summarised history of pastoral abstraction (Figure 4-2). Flow rates were measured in 24 pastoral bores and estimated in 9 in June 2010 (Table 4-3). Some variations to flow rates compared to results presented last year are noted, in particular for Kopperamanna bore where the bore drain was turned off in November 2009. Other bores on Etadunna station, including Boolcaltaninna, Cannuwaukaninna and Georgia also had a reduction in flow following the purchase of the station by BHP Billiton saving approximately 4.1ML/d. Total estimated pastoral abstraction from bores in the immediate wellfield area at the end of June 2010 was 14.8ML/d, compared to 18.4ML/d for the same period in 2009. The peak pastoral flow since the commencement of monitoring was 38.1ML/d in mid-1997. Boredrain closure is the major contributor to the reduction in pastoral flow. Approximately 34% of the total flow from pastoral bores in the wellfields region is from five bores with flows of 1.0ML/d or greater.
4.4 Total Abstraction Total abstraction from the wellfields area, including OD sources and the 32 pastoral bores rose from about 40.0ML/d in 1995 to 60.0–70.0ML/d in 2000–01 and has subsequently declined to between 45.0–50.0ML/d in 2006–09 (Figure 4-2). Total abstraction from the wellfields area in FY10 was 36.7ML/d, due to a reduced demand for water following the failure of the Clark Shaft and a reduction in pastoral abstraction over the period.
ABSTRACTION PAGE 17 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table 4-1: Wellfields average annual daily abstraction rate
Year Ended Wellfield A Wellfield B Total 30-Jun-1986 1.3 0.0 1.3 30-Jun-1987 2.2 0.0 2.2 30-Jun-1988 4.4 0.0 4.4 30-Jun-1989 8.9 0.0 8.9 30-Jun-1990 10.0 0.0 10.0 30-Jun-1991 10.6 0.0 10.6 30-Jun-1992 11.6 0.0 11.6 30-Jun-1993 12.6 0.0 12.6 30-Jun-1994 12.1 0.0 12.1 30-Jun-1995 13.5 0.0 13.5 30-Jun-1996 15.1 0.0 15.1 30-Jun-1997 8.2 7.4 15.6 30-Jun-1998 5.3 12.3 17.6 30-Jun-1999 4.9 17.3 22.1 30-Jun-2000 5.2 26.2 31.4 30-Jun-2001 6.1 25.5 31.5 30-Jun-2002 6.0 24.7 30.7 30-Jun-2003 6.1 25.3 31.4 30-Jun-2004 5.4 26.0 31.4 30-Jun-2005 5.9 28.1 34.0 30-Jun-2006 4.9 29.4 34.3 30-Jun-2007 4.5 27.9 32.5 30-Jun-2008 4.3 29.1 33.5 30-Jun-2009 4.6 27.8 32.4 30-Jun-2010 2.3 19.6 21.9 Note: • Sum of individual rows may not exactly match totals due to rounding.
PAGE 18 ABSTRACTION BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT Table 4-2: Monthly average abstraction rate (ML/d), FY10
Wellfield A Wellfield B Wellfields GAB06 GAB12 GAB14 GAB15 GAB16 GAB18 Total GAB51 GAB52 GAB53 Total Total Jul-09 0.5 0.9 0.0 0.6 1.1 0.4 3.5 7.1 6.4 8.2 21.7 25.2 Aug-09 0.5 0.6 0.0 1.2 1.3 0.0 3.6 10.3 8.1 10.7 29.0 32.6 Sep-09 0.5 1.5 0.0 0.0 0.0 0.0 2.0 10.6 8.3 10.9 29.8 31.8 Oct-09 0.5 1.4 0.0 0.0 0.0 0.0 1.9 6.0 4.4 6.6 17.0 18.9 Nov-09 0.5 1.3 0.0 0.0 0.0 0.0 1.9 4.1 3.8 4.9 12.9 14.7 Dec-09 0.2 0.6 0.0 0.0 0.0 0.0 0.9 4.9 4.4 5.6 14.9 15.7 Jan-10 0.2 0.2 0.0 0.0 0.0 0.0 0.4 3.8 3.6 3.7 11.1 11.4 Feb-10 0.2 0.2 0.0 0.0 0.0 0.0 0.4 4.0 3.7 3.9 11.6 12.0 Mar-10 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.3 4.2 5.0 14.5 14.5 Apr-10 0.7 0.5 0.0 0.7 0.8 0.0 2.7 7.1 5.6 8.0 20.8 23.5 May-10 1.1 1.4 0.0 0.7 2.0 0.0 5.2 8.7 6.7 9.5 24.9 30.1 Jun-10 0.6 1.7 0.0 0.5 2.2 0.0 5.0 9.5 7.2 10.2 26.8 31.9 Average 0.5 0.9 0.0 0.3 0.6 0.0 2.3 6.8 5.5 7.3 19.6 21.9 Total ML 169.0 317.0 0.0 112.4 227.5 13.1 839.0 2476.2 2024.3 2657.0 7157.5 7996.5 Note: • Sum of individual rows may not exactly match totals due to rounding.
PAGE 19 ABSTRACTION
1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table 4-3: Abstraction rates measured and estimated at pastoral bores in the wellfields area, June 2010
(ML/d) Measured (M) / Estimated (E) Big Bore 0.3 E Boocaltaninna 0.2 M Cannuwaukaninna 0.3 M Chapalanna 0.3 M Charles Angus 0.1 M Clayton 1 0.4 M Clayton 2 0.8 M Clayton Dam 0.3 M Cooranna <0.1 E Cooryaninna 0.2 M Crows Nest 0.0 M Dulkaninna 1.0 M Frome Creek 0.0 M Georgia 0.2 M Highway (Brolga) 0.0 M Jackboot 0.0 M Jewellery Creek 1.3 M Kopperamanna 0.1 M Lake Harry 0.2 M Marion <0.1 E Maynards 0.0 M Morphetts 0.2 M Morris Creek 0.2 M Mulka 0.5 E Muloorina 2.2 M Mungeranie 1.0 E Peachawarinna 0.5 M Peters <0.1 E Poonarunna 3.4 E Prices 0.2 E Sinclair <0.1 E Tarkanina 0.1 M Yarra Hill 1.0 M Total 14.8
• Sum of individual rows may not exactly match totals due to rounding. • Abstraction rates for some bores is shown as both measured and estimated, where some component of the flow is directly measurable and the remainder is not. • Jackboot switched off in January 2010. • Boolcaltaninna, Cannuwaukaninna, and Kopperamanna reduced incrementally over the September 2009 – November 2009 period to current levels. • Bores measured in June 2010
ABSTRACTION PAGE 21 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
40
35
30 d) L/
M 25 ( e t a
n r 20 o i t c a r
t 15 s b A 10
5
0 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- u u u u u u u u u u u u u u u u u u u u u u u u u u u J J J J J J J J J J J J J J J J J J J J J J J J J J J
Wellfield A Wellfield B Figure 4-1: Historical abstraction from Wellfields A and B – 3 month moving average
80
70
60 d) L/
M 50 ( e t a
n r 40 o i ct a
r 30 st b A 20
10
0 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- u u u u u u u u u u u u u u u J J J J J J J J J J J J J J J
Wellfield A Wellfield B Pastoral Figure 4-2: Total abstraction from the Wellfields area – 3 month moving average
PAGE 22 ABSTRACTION BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
5 WELLFIELD A AREA AQUIFER RESPONSE
Wellfield A drawdown is measured in relation to reference heads established in May 1986. It is noted that these heads incorporate some localised drawdown due to the prior operation of production bore GAB6. A summary of reference heads and the change in drawdown between June 2009 and June 2010 is shown in Table 5-1. Drawdown contours as at June 2010 are presented in Figure 5-1. The contour map for Wellfield A has been updated to better reflect the influence of the geological structures surrounding the Wellfield sub-basin.
5.1 Monitoring Program Requirements 5.1.1 Purpose • Quantify by routine and appropriate methods water pressures and water levels in all monitoring and production wells, and at the boundary of the designated areas, as agreed with the State. • Measure or infer the magnitude of the drawdown within the designated area of Wellfield A. 5.1.2 Action Triggers • A drawdown trend at the Designated Area boundary for Wellfield A that is expected to exceed 4m at the point between GAB8 and HH2 (measured as the average drawdown at the two bores) and 5m at Jackboot bore. • Continued abstraction of water is identified to be detrimental to the water resource or there is a reasonable possibility of a complete or partial failure of the water supply. • A continuing drawdown trend at pastoral bores that may exceed the predictions of the Environmental Impact Statement (Kinhill Engineers, 1997). • Failure or anticipated failure of pastoral water supplies which can be attributed to drawdown caused by abstraction from Wellfield A.
5.2 Wellfield A Sub-Basin 5.2.1 Groundwater Head In general, groundwater heads within the sub-basin remain within a narrow range, as they have since 1998 (Table 5-1, Figure 5-2). Several bores have continued to experience a reduction in drawdown whilst the remainder appear stable. Pressure measurements were not taken in December 2009 and March 2010 as it was identified that the large concrete caissons on the bores posed a safety risk. This was rectified by replacing existing caissons with smaller steel covers and monitoring resumed in June 2010. Groundwater head within the sub-basin increased over the reporting period – thought to be due in part to the reduction in abstraction from Wellfield A and also to the absence of elevation corrections in previous data. During the process of surveying new reference levels it was identified that no corrections had been applied in the past to account for the change in gauge elevation associated with the existing large concrete caissons. This would have resulted in a groundwater head decrease at the time of the caissons installation in the late 1990’s and, as is now apparent, a groundwater head increase caused by a reduction in gauge elevation. As monitoring was restricted over the period when Wellfield A abstraction was reduced it is difficult to determine exactly what proportion of the apparent increase in groundwater head is associated with the absence of elevation corrections and what is
PAGE 23 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT associated with regional recovery. Changes in gauge elevation associated with the large concrete caissons would vary between bore but it is estimated that it would equate to a negative error of 0.5 – 1.0m during the time the caissons were installed (late 1990s – 2009). During this time reported groundwater head would have been erroneously low and thus the step change to the June 2010 reading (which has the correct elevation correction applied) appears greater than in reality. Change in drawdown for bores within the Wellfield sub-basin range from 0.4m at GAB21 to -2.4m at GAB13A. Whilst the extent would vary slightly between bores it is estimated that approximately 0.5 – 1.0m of the change in drawdown would be due to the absence of elevation corrections in past data and the remainder due to regional groundwater head recovery. Every effort will be made to rectify gauge elevation corrections for subsequent reports. 5.2.2 GAB Spring and Bore Flow Rates Flow rates at all of the monitored vents are within the range of historical observations (Figure 5-3; see also Appendix 3). Within the Wellfield sub-basin there was a trend of increasing flow rate at LES001 and LMS004B, further supporting a regional groundwater head increase associated with reduced abstraction from Wellfield A. Further details are given in Section 7.2.
PAGE 24 WELLFIELD A AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table 5-1: Wellfield A – summary of drawdown and recovery
Mean Mean Reference Change in Area Bore Drawdown Drawdown drawdown elevation FY09 FY10 (m AHD) (m) (m) (m) Wellfield GAB1 22.4 8.1 7.0 -1.1 Sub-basin GAB2 22.8 7.4 7.3 -0.2 GAB5A 27.7 6.5 5.4 -1.1 GAB13A 30.4 14.6 12.2 -2.4 GAB17 28.4 15.4 - - GAB21 25.4 10.2 10.6 0.4 GAB22 24.7 13.0 10.8 -2.2 GAB23 27.7 16.3 - - New Years Gift 22.6 8.9 7.5 -1.4 MB2 22.2 5.8 5.2 -0.6 North east GAB7 16.0 2.9 2.5 -0.4 Sub-basin GAB8 11.7 2.1 1.8 -0.2 GAB10 19.0 2.8 2.4 -0.4 GAB11 20.7 2.5 2.1 -0.4 GAB19 15.1 2.8 2.3 -0.5 HH2 8.2 1.1 1.0 -0.2 Hermit Hill HH1 11.1 0.0 -0.1 -0.1 HH3 9.3 -0.1 -0.1 0.0 HH4 14.0 0.1 0.0 -0.1 Extension GAB24 39.2 6.4 5.0 -1.4
Mean Mean Reference Change in Area Bore Drawdown Drawdown pressure drawdown FY09 FY10 (kPa) (kPa) (kPa) (kPa) Northern Jackboot 645 39.4 24.2 -15.2 Notes: • No readings for GAB17 and GAB23 in FY10 due to bore flowing. • Jackboot reference pressure is 645kPa for Wellfield A.
WELLFIELD A AREA AQUIFER RESPONSE PAGE 25
BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Note: • Negative drawdown at HH1 and HH3 have been reported here as 0.0m. Figure 5-1: Wellfield A total drawdown contours for FY10, contour interval 2m.
PAGE 27 WELLFIELD A AREA AQUIFER RESPONSE
1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
20 15 d / 10
ML 5 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
Wellfield A 3 month average ) D
H 40 A
m 30 ( d
a 20 he
r 10 e t
a 0 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 87 88 89 90 91 92 93 94 95 96 97 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- oundw Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju r G GAB2 GAB5A GAB13A ) D
H 40 A
m 30 ( d
a 20 he
r 10 e t
a 0 8 9 0 1 2 3 4 5 6 7 8 9 0 4 5 6 7 8 9 0 1 2 3 4 5 6 7 9 9 0 0 0 0 0 0 0 0 0 0 1 8 8 8 8 8 8 9 9 9 9 9 9 9 9 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- oundw Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju r G GAB24 GAB33A
Figure 5-2: Wellfield A Sub-basin – groundwater head
WELLFIELD A AREA AQUIFER RESPONSE PAGE 29 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
20
d 15 / 10
ML 5 0 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
Wellfield A 3 month average 4.0 ) s
/ 3.0 L (
e
t 2.0 a r 1.0 ow
Fl 0.0 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 87 88 89 90 91 92 93 94 95 96 97 un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J J J J J J J J J J J J J J J J
Emerald LES001 McLachlan LMS004B Beatrice Bore HBS004 )
s 3.0 / L (
e
t 2.0 a r 1.0 ow Fl 0.0 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 87 88 89 90 91 92 93 94 95 96 97 un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J J J J J J J J J J J J J J J J
Fred LFE001 Gosse LGS004 Bopeechee HBO004
Figure 5-3: Wellfield A and North-east Sub-basin – spring flow rates
PAGE 30 WELLFIELD A AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
5.3 North east Sub-Basin 5.3.1 Groundwater Head Groundwater head throughout the North east sub-basin (NESB) increased throughout the reporting period (Table 5-1, Figure 5-6). Similar to the Wellfield sub-basin, it is expected that this is in part due to the absence of gauge elevation corrections prior to September 2009. Change in drawdown for bores within the NESB ranged from -0.2m to -0.5m during the reporting period. Groundwater head in the North east sub-basin would not be expected to respond to decreased abstraction from Wellfield A to the same extent as the Wellfield sub-basin due to the presence of structural faults. Therefore the majority of the apparent groundwater head increase is estimated to be due to the absence of gauge elevation corrections in past data. Every effort will be made to rectify gauge elevation corrections for subsequent reports. 5.3.2 GAB Spring and Bore Flow Rates Flow rates at all of the monitored vents continue to remain within the range of historical observations (Figure 5-3; see also Appendix 3). No new trends are evident in the data and flow rates have been fluctuating within a narrow range at each site for several years.
5.4 Hermit Hill 5.4.1 Groundwater Head Monitoring bores on the east side of Hermit Hill (HH1, HH3 and HH4) continued to show near full pressure recovery (Figure 5-7). Groundwater head is very stable and remains virtually static for the year. 5.4.2 GAB Spring Flow Rates The GAB spring flow rates in the area remained relatively stable during the reporting period, and remain consistent with historical averages (Figure 5-7).
5.5 Boundary of Wellfield A Designated Area 5.5.1 Compliance Bores The designated area boundary runs between bores GAB8 and HH2, with reference pressures of 11.7m and 8.2m AHD respectively. Boundary drawdown is determined as the average drawdown at these two sites. At the end of the reporting period average boundary drawdown was 1.4m, compared to 1.6m in FY09 (Figure 5-4 and Figure 5-8). Twelve month average drawdown at Jackboot Bore (Figure 5-5 and Figure 5-8) decreased by 1.6m over the period, giving a total drawdown at this bore of 2.9m, based on the 645kPa Wellfield A reference pressure. The overall trend is that apparent pressure at Jackboot is increasing following BHP Billiton’s purchase of the Lake Eyre pastoral lease in June 2009 and the subsequent reduction in pastoral flow, suggesting a more accurate reflection of the true drawdown at that point. The apparent drawdown at Jackboot Bore now better reflects the drawdown predicted by the ODEX6 model. A significant amount of work has been carried out, and commitment made, over the last 12 months to investigate and address the apparent drawdown at Jackboot. To improve the monitoring capacity around Jackboot, and more generally in the western portion of the Wellfield B designated area, a program of works was committed to. A summary of the progress to date can be found in Section 11.
WELLFIELD A AREA AQUIFER RESPONSE PAGE 31 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
-2.0
-1.0
0.0 ) m
( 1.0 n w do w
a 2.0 Dr
3.0
4.0
5.0 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 ------c c c c c c c c c c c c c c c c c c c c c c c c c c c De De De De De De De De De De De De De De De De De De De De De De De De De De De
GAB8 / HH2 Avg. 12MMA Figure 5-4: Wellfield A Compliance Bores – GAB8/HH2
-2.0
-1.0
0.0
1.0
2.0
3.0 )
m 4.0 n ( 5.0 dow w
a -2.0 r D -1.0
0.0
1.0
2.0
3.0
4.0
5.0 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 ------c c c c c c c c c c c c c c c c c c c c c c c c c De De De De De De De De De De De De De De De De De De De De De De De De De
Wellfield A (645kPa) Wellfield B (641kPa) 12MMA Figure 5-5: Wellfield A Compliance Bores - Jackboot
PAGE 32 WELLFIELD A AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
20 15 d / 10
ML 5 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Wellfield A 3 month average 22
20
) 18 D H A
m 16 ( d a e h
14 r e t a
dw 12 oun r
G 10
8 GAB20 injection
6 8 9 0 1 2 3 4 5 6 7 8 9 0 4 5 6 7 8 9 0 1 2 3 4 5 6 7 9 9 0 0 0 0 0 0 0 0 0 0 1 8 8 8 8 8 8 9 9 9 9 9 9 9 9 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
GAB8 GAB10 GAB11 GAB20 GAB19 HH2
Figure 5-6: Wellfield A North-east Sub-basin – groundwater head
WELLFIELD A AREA AQUIFER RESPONSE PAGE 33 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
20
d 15 / 10
ML 5 0 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
Wellfield A 3 month average )
D 16 H
A 14 m (
d 12 a
he 10 r e t
a 8 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 87 88 89 90 91 92 93 94 95 96 97 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- undw o r Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju G HH1 HH3 HH4 )
s 0.8 / L (
e 0.6 t a r 0.4 w o l
f 0.2 nt e 0.0 ng v 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 87 88 89 90 91 92 93 94 95 96 97 i n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Spr Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
Hermit Hill HHS170 Old Finniss HOF081 Old Finniss HOF096
Figure 5-7: Hermit Hill area – groundwater head and spring flow rates
PAGE 34 WELLFIELD A AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
20 15 d / 10
ML 5 0 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 4 5 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J J J J J J J J J J J J J J J J
Wellfield A 3 month average )
a 680 P k
( 660 e r 640 620 essu r
p 600 r e f 580 ui q 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 87 88 89 90 91 92 93 94 95 96 97 A Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
Jackboot Jackboot 12MMA ) D
H 12 A m 8 ad (
he 4 er
at 0 w d 98 99 00 01 02 03 04 05 06 07 08 09 10 84 85 86 87 88 89 90 91 92 93 94 95 96 97 n u n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- u u u u u u u u u u u u u u u u u u u u u u u u u u u o r J J J J J J J J J J J J J J J J J J J J J J J J J J J G GAB8 / HH2 Avg. GAB8 / HH2 12MMA
Figure 5-8: Wellfield A – SWL boundary aquifer pressure
WELLFIELD A AREA AQUIFER RESPONSE PAGE 35 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
6 WELLFIELD B AREA AQUIFER RESPONSE
Drawdown is measured as pressure loss from reference pressures established for each of the bores monitored. A summary of reference pressures and average drawdown to June 2010 for both Wellfield B and pastoral bores is shown in Table 6-1 and Table 6-2. Average drawdowns for the reporting period are presented in Table 6-1 and Figure 6-1. Averages have not been used in Table 6-2 since for the majority of these bores SIP is only measured annually, or not at all. Discussion of drawdown in the following sections refers to yearly averages. In FY10 BHP Billiton completed four new monitoring bores (MB5 – 8) to enhance the existing groundwater monitoring infrastructure associated with groundwater abstraction from Wellfield B in the GAB (Figure 6-1). • MB5 replaced the dysfunctional MB4 monitoring bore. • MB6 is to monitor head near the western GAB springs. • MB7 and MB8 are to monitor drawdown from Wellfield B. The bores range between 250 and 722m deep and are equipped with vibrating wire and temperature sensors to monitor pore pressure and temperature at six different depths each. Early measurements from the new bores have improved groundwater monitoring and better defined the drawdown pattern to the west of Wellfield B. More information can be found in Section 11. Interpreted total drawdown contours, averaged over the reporting period, are shown in Figure 6-1. Total drawdown contours are a combination of the impacts of both Wellfields A and B as well as that of third parties. Further investigations to assess these different components of drawdown are being conducted. In reviewing the drawdown trends described below it should be noted that the response time of Wellfield B monitoring bores to changes in abstraction rate varies considerably, according to distance from the production wells, aquifer thickness and continuity between the two points. In the centre and north (S5, D2, D3), the response time is about 1–3 months, increasing to 4–5 months at S4, S3A and Crows Nest, and more than 12 months at S1, S2 and Wellfield A. 6.1 Monitoring Program Requirements 6.1.1 Purpose • Quantify by routine and appropriate methods water pressures and water levels in all monitoring and production wells, and at the boundary of the designated areas, as agreed with the State Government. • Measure or infer the magnitude of the drawdown within the designated area of Wellfield B. 6.1.2 Action Triggers • A drawdown trend that may exceed 5m at the corners of the designated area boundary of Wellfield B. • Continued abstraction of water is identified to be detrimental to the water resource or there is a reasonable possibility of a complete or partial failure of the water supply. • A continuing drawdown trend at pastoral bores that may exceed the predictions of the Environmental Impact Statement (Kinhill Engineers, 1997).
PAGE 36 WELLFIELD B AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
• Failure or anticipated failure of pastoral water supplies which can be attributed to drawdown caused by abstraction from Wellfield B.
6.2 Overall Response and Boundary of Wellfield B Designated Area A summary of drawdown at key monitoring and pastoral bores is shown in Table 6-1 and Table 6-2, with interpreted drawdown contours across the Wellfield B region shown in Figure 6-1. The aquifer thickness and controlling structural and palaeogeographic boundaries shown in Figure 6-1 are from seismic, gravity and drilling data collected across the region. The drawdown cone shows marked asymmetry, reflecting structural and palaeogeographical control over drawdown impacts. The production wells are situated in a north to north west oriented wide basin trough, which contains a thicker, more transmissive aquifer sequence. The trough is flanked by up-lying and structurally disrupted zones, which limit the transmission of drawdown to the east and west (WMC, 1995). There was a tightening in the drawdown contours over the reporting period most likely caused by the reduction in abstraction from Wellfield B following the failure of the Clark Shaft. The tightening is apparent close to the wellfield and along the basin trough with a drawdown reduction in the order of one metre measured at Muloorina, S5, Lake Harry and Marion. It should be noted that Figure 6-1 presents total drawdown, and the impact of the closure of Crows Nest bore in FY08 is an indication that some drawdown may be caused by pastoral wells. The separation of Olympic Dam and drawdown caused by pastoral and other bores, however, is not straightforward especially for sites with small drawdown. The maximum twelve month moving average drawdown at a corner point for the review period was 3.6m at the north east corner near D2.
WELLFIELD B AREA AQUIFER RESPONSE PAGE 37
BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT Table 6-1: Wellfield B – summary of drawdown to June 2010
Zone Bore CRP PRP Mean Mean (kPa) (kPa) Drawdown Drawdown Change in Mean FY09 (kPa) FY10 (kPa) Drawdown (kPa) Northern D2 728 807 32.6 35.2 2.6 D3 531 555 72.9 69.0 -3.9 S5 731 767 124.3 111.1 -13.2 Southern S1 325 325 5.5 5.6 0.1 S2 70 70 0.5 -1.5 -2.0 S3 363 363 8.8 6.9 -1.9 S3A 454 454 82.9 84.7 1.8 S4 413 413 84.8 85.3 0.5 WCB1 – 190 -6.9 -14.5 -7.6 Crows Nest OB1 780 780 27.5 33.6 6.1 OB3 807 807 46.1 40.5 -5.6 OB6 735 734 77.8 75.1 -2.7 WCB2 617 617 57.9 57.7 -0.2 Pastoral Georgia – 926 82.4 80.1 -2.3 Jackboot – 641 39.4 24.2 -15.2 Tarkanina #2 – 242 *22.8 30.7 7.9 Peters – 294 15.9 16.9 1.0 Notes: • Jackboot reference pressure is 641kPa for Wellfield B. • Change in Mean Drawdown (kPa) is calculated as the difference between Mean Drawdown for FY09 and FY10. • No measurements were taken at Tarkanina #2 in FY09, value given is for FY08.
PAGE 39 WELLFIELD B AREA AQUIFER RESPONSE BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table 6-2: Drawdown at selected pastoral bores in the wellfields area to June 2010
Baseline EIS Drawdown Measured or Drawdown Wellhead Predicted (kPa) Estimated (%) Pressure(kPa) Drawdown (%) Charles Angus 444 -18 M -4 6 Clayton 2 352 77 E 22 27 Cooranna 222 -171 M -77 16 Crows Nest 662 39 E 6 13 Dulkaninna 617 30 M 5 10 Lake Harry 453 106 M 23 32 Marion 268 90 M 34 48 Muloorina 779 88 M 11 18 Peachawarrina 779 104 E 13 15 Peters 294 16 M 5 35 Notes: • EIS (Kinhill Engineers, 1997) predicted drawdown is for the period 1996–2016. • Cooranna baseline pressure is given in the EIS as 61kPa. This is an incorrect value for the bore and represents a flow pressure rather than a shut-in pressure. • Crows Nest is difficult to estimate accurately due to steep drawdown gradients and structural influences in the region.
PAGE 40 WELLFIELD B AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Note: • Negative drawdown at Charles Angus, S2 and WCB1 have been reported here as 0.0m. Figure 6-1: Wellfield B total drawdown contours for FY10, contour interval 2m.
WELLFIELD B AREA AQUIFER RESPONSE PAGE 41
1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
6.3 Northern Observation Bores Drawdown at D2 for FY10 was 35.2kPa (3.6m). Drawdown at D2 remained stable over the reporting period, with none of the characteristic short-term fluctuations being observed (Figure 6-2). A revised practical reference pressure (PRP) of 807kPa was approved by the Government in June 2010. More details can be found in Section 11. Drawdown at D3 decreased by 3.9kPa (0.4m) during this reporting period to finish at 69.0kPa (7.1m) compared with 72.9kPa (7.5m) for FY09 . Drawdown at S5 decreased by 13.2kPa (1.3m) for the period (Figure 6-4). Both D3 and S5 appear to have responded to the decrease in abstraction from Wellfield B.
6.4 South east Observation Bores Drawdown in the south east zone (Figure 6-5) remained relatively stable throughout FY10. Drawdown increased at S3A by 1.8kPa and S4 by 0.5kPa while S3 finished the period 1.9kPa lower (Figure 6-2). Overall drawdown is 0.7m at S3 and 8.7m at the nearby S3A, highlighting the extreme drawdown gradient in this area.
6.5 Eastern Springs Zone Drawdown at S1 increased by 0.1kPa (Figure 6-3), S2 decreased by 2.0kPa and at WCB1 drawdown decreased by 7.6kPa over the 12 month period. Overall drawdown in this area remains very low to neutral, or has recovered from historical reference values in the case of WCB1 and S2, and is very stable. Note that the early portion of the hydrograph for WCB1 presented in Figure 6-5 has been corrected for higher flows that occurred from the bore before 2000. A slight leak at WCB1 prior to 2000 caused lower measured SIP values due to the antecedent flow, with average SIP over this period being 190.0kPa. From January 1999 the leak increased and recorded values in the period from May 1999 to May 2000 have been discarded from the hydrograph in Figure 6-5. Since August 2000, after the leak was repaired, the average SIP has been 198.0kPa, a difference of 8.0kPa above that recorded for the period prior to January 1999. In order not to mask any potential effects of drawdown from Wellfield B, and to account for the lower measured SIP readings, recorded values in the period before January 1999 have been corrected upward by 8.0kPa. Key GAB spring flow rate monitoring includes three vents at Welcome and Davenport Springs (Figure 6-6). Flow rates at all three vents are stable and are consistent with historical values.
WELLFIELD B AREA AQUIFER RESPONSE PAGE 43
-2.0
-1.0
0.0 ) m
( 1.0 n w o d w
a 2.0 Dr
3.0
4.0
5.0 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 ------c c c c c c c c c c c c c c c De De De De De De De De De De De De De De De
D2 S3 12MMA Figure 6-2: Wellfield B Compliance Bores – D2 and S3
-2.0
-1.0
0.0 )
m 1.0 n ( dow w
a 2.0 r D
3.0
4.0
5.0 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 ------c c c c c c c c c c c c c c c De De De De De De De De De De De De De De De
S1 Tarkanina #2 12MMA Figure 6-3: Wellfield B Compliance Bores – S1 and Tarkanina #2
PAGE 44 WE
BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
30 d / 20
ML 10 0 98 99 00 01 02 03 04 05 06 07 08 09 10 96 97 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
Wellfield B 3 month average
) 790 Pa k
( 750 e r u
s 710 s e 670 Pr 630 04 05 06 07 08 09 10 96 97 98 99 00 01 02 03 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
D2 S5 12MMA 560 )
a 540 P k 520 re (
su 500 es r 480 P 460 04 05 06 07 08 09 10 96 97 98 99 00 01 02 03 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
D3 12MMA
Figure 6-4: Wellfield B northern monitoring bore pressures
PAGE 46 WELLFIELD B AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
30 d / 20
ML 10 0 10 98 99 00 01 02 03 04 05 06 07 08 09 96 97 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
Wellfield B 3 month average 460 440
Pa) 420 k (
400 e r 380 u
s 360 es 340
Pr 320 300 4 5 6 7 8 9 0 6 7 8 9 0 1 2 3 0 0 0 0 0 0 1 9 9 9 9 0 0 0 0 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
S1 S3 S3A S4 12MMA 220 200
Pa) 180 k (
160 e r 140 u
s 120 es 100
Pr 80 60 4 5 6 7 8 9 0 6 7 8 9 0 1 2 3 0 0 0 0 0 0 1 9 9 9 9 0 0 0 0 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
S2 WCB1 (Corrected) 12MMA
Figure 6-5: Wellfield B southern monitoring bore pressures
WELLFIELD B AREA AQUIFER RESPONSE PAGE 47 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
30 d / 20 L
M 10 0 10 96 97 98 99 00 01 02 03 04 05 06 07 08 09 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
Wellfield B 3 month average 1.2
) 1.0 s /
L 0.8 ( e t 0.6 a r 0.4 ow
Fl 0.2 0.0 04 05 06 07 08 09 10 96 97 98 99 00 01 02 03 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
Davenport WDS001 1.2
) 1.0 s /
L 0.8 ( e t
a 0.6 r 0.4 ow
Fl 0.2 0.0 04 05 06 07 08 09 10 96 97 98 99 00 01 02 03 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
Welcome WWS 002 Welcome WWS 004
Figure 6-6: Wellfield B area spring flow rates
PAGE 48 WELLFIELD B AREA AQUIFER RESPONSE
BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
6.6 Crows Nest Area The drawdown trend at bores in the Crows Nest Area varies. At OB3, OB6 and WCB2 drawdown remained relatively stable throughout the reporting period. Drawdown at OB1 increased, most likely due to a leak at Crows Nest bore which has developed over the last 18 months. Drawdown at OB1 increased by 6.1kPa (0.6m), whilst OB3 drawdown decreased by 5.6kPa (0.6m). OB6 also decreased by 2.7kPa (0.3m). Drawdown at WCB2 decreased 0.2kPa and has remained relatively stable throughout the period (Figure 6-7).
6.7 Key Pastoral Bores Key pastoral bores (Figure 6-8) are those that can provide reliable shut-in data in areas far from OD monitoring bores. Currently these include Georgia, Tarkanina and Peters bores. The Jackboot hydrograph is shown in Figure 5-5, Figure 5-8 and discussed in Section 5.5.1. The twelve month moving average drawdown for Jackboot Bore decreased by 15.2kPa (1.6m), finishing the period at 24.2kPa (2.5m), based on the 641kPa Wellfield B reference pressure. Apparent drawdown at Jackboot is decreasing following BHP Billiton’s purchase of the Lake Eyre pastoral lease in June 2009 and the subsequent reduction in pastoral flow. The current 2.5m now better reflects the drawdown predicted by the ODEX6 model. Drawdown appears to be a more accurate reflection of the true drawdown than those influenced by antecedent pastoral flows and reported since 2004. At Georgia bore, total drawdown finished the period at 80.1kPa (8.2m), a decrease of 2.3kPa (0.2m) from FY09. Pastoral abstraction from the bore remained steady over the reporting period following a reduction to current levels at the end of FY09. Average drawdown at Peters increased by 1.0kPa for the period, finishing at 16.9kPa (1.7m). Table 6-1 lists average drawdown for Peters while Table 6-2 lists instantaneous drawdown as of June 2010 The large fluctuations in pressure have been eliminated by repairs to the headworks and also permitted monitoring to resume from September 2006. Drawdown recovered slightly over the reporting period, most likely due to the decrease in abstraction from Wellfield B. A new reference level for the bore has yet to be surveyed. Marion bore pressure decreased by 12.0kPa (1.2m) over the reporting period. SIP at Tarkanina #2 is sensitive to antecedent flow rates and a correction based on antecedent flow pressure has been developed (WMC, 2004). Total drawdown finished the period at 30.7kPa (3.1m) (Figure 6-3). No measurements were taken at Tarkanina #2 between December 2007 and March 2010 due to restrictions on access by the pastoralist so this is a decrease of 7.9kPa (0.8m) from the FY08 average.
PAGE 50 WELLFIELD B AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
30 d / 20
ML 10 0 98 99 00 01 02 03 04 05 06 07 08 09 10 96 97 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
Wellfield B 3 month average
800
750 )
a 700 P k ( e r
su 650 es r P 600
550
500 04 05 06 07 08 09 10 96 97 98 99 00 01 02 03 n- n- n- n- n- n- n- n- n- n- n- n- n- n- n- Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju Ju
OB1 OB3 OB 6 WCB2 12MMA
Figure 6-7: Wellfield B Crows Nest area monitoring bore pressures
WELLFIELD B AREA AQUIFER RESPONSE PAGE 51 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
30 d / 20
ML 10 0 10 98 99 00 01 02 03 04 05 06 07 08 09 96 97 un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J J J J
Wellfield B 3 month average 330 320 310 300 290 )
a 280 P k 270 e ( r u 260 ess r 250 P 240 230 220 210 200 04 05 06 07 08 09 10 96 97 98 99 00 01 02 03 un- un- un- un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J J J J
Peters Tarkanina #2 12MMA
Figure 6-8: Wellfield B pastoral bore pressure
PAGE 52 WELLFIELD B AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
6.8 Drawdown Impacts on Pastoral Bore Operation Total drawdown at pastoral bore sites can be assessed from Figure 6-1, which shows drawdown contours in the Wellfield B area due to all groundwater abstractions. A summary of measured or inferred (estimated from Figure 6-1 if SIP was not measured) drawdown is shown in Table 6-2. Note that baseline pressure values shown in Table 6-2 are mostly those reported by Golder Associates (1997), based on a single measurement taken in 1995–96. For some of the key pastoral bores (Jackboot, Peters, Marion and Muloorina bores; BHP Billiton, 2006), however, the baseline pressures are slightly different, based on a review of more comprehensive monitoring data. There are also slight differences from those in the EIS (Kinhill Engineers, 1997), which in some cases are based on considerably earlier measurements. These slight differences have little effect on the percentage pressure loss, which is the primary basis for assessment of the impact of drawdown on a pastoral bore function. Maximum wellhead pressure loss of 106kPa was at Lake Harry whilst maximum pressure loss as a percentage of baseline pressure was 34% at Marion, again as in the last reporting period. The large discrepancy in drawdown at Cooranna compared to the predictions of the EIS come about as a result of the change to a closed pipe system. In general drawdown and percentage pressure loss at pastoral bores remains less than the predicted long-term impact as presented in the EIS (Kinhill Engineers, 1997). To the south east of Wellfield B and beyond the SWL in the Mundowdna area drawdown is about 20% greater than early model predictions, due to the thin and discontinuous nature of the aquifer. Localised variations result in large changes in drawdown over short distances, such as between S3 and nearby S3A. These factors and the hydraulic connection to the wellfield make it particularly difficult to predict the pattern of drawdown in the area. To better understand and predict the drawdown in this area, additional bores (Two Mile, Lake Billy #2, Tent Hill, Well Creek and Wirringina Spring) on Mundowdna Station were equipped with necessary monitoring equipment during FY05 and quarterly monitoring commenced. The limited number of readings available and variations in the method of operation of bores (notably Lake Billy #2) means that any significant interpretation or analysis has not yet been possible. However, apparent trends since monitoring commenced in August 2005 are shown in Figure 6-9 and Figure 6-10. The pressure values in Figure 6-9 are plotted relative to the first reading. Well Creek #2 is generally stable, with the apparent recovery of this bore in FY07 due to being changed from continual flow to a pipe and trough system. There was a ~10 kPa pressure drop at Tent Hill #2 at the end of FY08 but this has recovered to within past ranges. Tent Hill #2 intersects a very poor part of the aquifer and is unable to sustain flow, thus measurement errors can be significant. The significant fluctuations at Lake Billy #2, as a result of changes in operation of the bore have disappeared since September 2008. In similar fashion, trends for Two Mile #2 and Wirringina Spring are plotted relative to the first reading but being sub-artesian are plotted as depth to water on the Y axis. Wirringina Spring appears to show a very small downward trend notwithstanding that there is an inherent difficulty in analysing trends that are smaller than measurement / interpretative errors. Monitoring at this spring should continue. Water levels at Two Mile continue to decline. The extent to which this is affected by localised pumping of the bore is unknown but there appears to be a relatively consistent downward trend.
WELLFIELD B AREA AQUIFER RESPONSE PAGE 53 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
60.0
50.0
40.0 ) a
P 30.0 k ( e r u
ess 20.0 r ve p i t a l
e 10.0 R
0.0
-10.0
-20.0 5 6 7 8 9 0 5 6 7 8 9 0 0 0 0 0 1 0 0 0 0 0 - - - - - c c c c c Jun- Jun- Jun- Jun- Jun- Jun- De De De De De
Lake Billy #2 Tent Hill 2 Well Creek #2 Figure 6-9: Monitoring trends, Mundowdna Station pressurised bores
-0.1
0.0
0.1 ) m
r ( 0.2 e t a w o
h t 0.3 pt de e v i t
a 0.4 l e R
0.5
0.6
0.7 5 6 7 8 9 0 5 6 7 8 9 0 0 0 0 0 1 0 0 0 0 0 - - - - - c c c c c Jun- Jun- Jun- Jun- Jun- Jun- De De De De De Two Mile #2 Wirringinna Spring MWI001
Figure 6-10: Monitoring trends, Mundowdna Station sub-artesian bores and springs
PAGE 54 WELLFIELD B AREA AQUIFER RESPONSE 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
7 GAB SPRING FLOW
Water abstraction from the GAB has the potential to reduce the flow of water from springs in the vicinity of a wellfield, in turn reducing the area of habitat that is available to organisms or increasing the rate of spring extinctions. A core group of 41 GAB springs in the vicinity of the wellfields are monitored every six months (Land Use Consultants, 2009 and 2010). During this monitoring, flow rates and chemistry field data are recorded (pH, conductivity, temperature).
7.1 Monitoring Program Requirements 7.1.1 Purpose Determine the extent of flow change at GAB springs within each hydrogeological zone of impact that may be attributed to water abstraction from Wellfields A and B. 7.1.2 Action Triggers Evidence that flow reductions at GAB springs may exceed the predictions made in the Environmental Impact Statements of 1982 and 1997.
7.2 Results Hydrographs from GAB springs can be difficult to interpret as long-term trends may be masked by fluctuations at a range of frequencies (Appendix 3, Figure 17-1 to Figure 17-41) and Appendix 4. The majority of springs monitored in April 2010 had measured flows within previously recorded ranges, and many were near to their average flow rate. Monitoring at HWF048 (Figure 17-28) changed during the period. In October 2009 the flow from an additional West Finniss spring; HWF086 was merging with the main tail of HWF048 above the weir point. In April 2010 another adjacent spring, HWF036 was flowing into the main tail of HWF048 and was measured to facilitate the accurate determination of flow. Despite this, recorded flow rates remained within previously recorded ranges. HHS170 (Figure 17-15) and WWS013 (Figure 17-41) were severely affected by water movement following rain events in the later half of FY10. HHS 170 is situated in the bed of Finniss Creek immediately adjacent to the main channel. Large volumes of silt had collected in spring vegetation, especially on the eastern side, completely blocking the tail on this side of the spring. WWS 013 is also within a creek bed and has little vegetation. This spring had been almost completely ‘washed’ of any sediment covering the hard substrate of the vent and tail areas. Despite this, both recorded flow rates were within historical ranges. In the past flow from WWS002 (Figure 17-39) has come solely from a horizontal PVC pipe placed in the vent area but during the reporting period a new vent has formed and flow from the PVC pipe has ceased. Despite the changes to spring morphology, the flow rate remained consistent with past recordings. HWF048 (Figure 17-28), LFE006 (Figure 17-31), and LMS004B (Figure 17-34) recorded higher flow rates during the reporting period however these where all within previously recorded ranges. Flow at WDS052 (Figure 17-37) also increased whilst flow decreased at WDS042 (Figure 17-36). Both springs recorded values within previously recorded ranges. For the thirteenth consecutive period a zero flow rate was recorded at HHS101 (Figure 17-12). There was no evidence of recent flow and observed moisture was due to flow from an adjacent spring. HOF033 (Figure 17-17) recorded zero flow in April 2009
GAB SPRING FLOW PAGE 55 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT however flow has since resumed. This low flow spring has recorded zero flows on three occasions in the past and subsequently recovered. The recorded flow rate at WWS001 (Figure 17-38) reduced significantly over the period and was the lowest recorded flow rate since April 2000. Field observation of this spring was congruent with the reduced flow. The reduced flow appears to be vent specific as none of the adjacent vents (WWS002, WWS004 and WWS013) indicate decreasing flows (Figure 17-39, Figure 17-40 & Figure 17-41). Beatrice (HBS004, Figure 17-7) was previously monitored annually as part of the Wellfield A bore monitoring program. Flow rate was measured by recording the time required to fill a 10L bucket. The bore was drilled into the spring and water delivered via a standpipe to the surface. In recent years the bore has become completely overgrown and inaccessible, and the standpipe is assumed to have collapsed, with the last measurement of flow rate being taken in June 2000. In order to obtain a flow rate measurement, in 2006 the spring was added to the list of springs to be monitored bi- annually by Land Use Consultants using weir gauging methods. Due at least in part to changes in the flow measurement method and the morphology of the spring, the recorded flow rate at HBS004 since monitoring resumed is significantly less than that previously recorded. However in April 2010, recorded flow was greater than that measured in April and October 2009. This result is a departure from the overall waning trend exhibited by this spring since 1985.
PAGE 56 GAB SPRING FLOW 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
8 GROUNDWATER CHEMISTRY
Assessment of spatial variation of groundwater chemistry throughout the wellfield and monitored area has been discussed previously by AGC (1982) and Habermehl (1983) and is not included in this report. In general, spatial variations in chemistry of the main GAB aquifer occur on a very broad scale. A review of groundwater chemistry data collected in the vicinity of the OD Wellfields has been provided in a previous wellfields report (WMC, 2002). Shallow aquifers containing saline water (20,000–50,000mg/L) occur in the vicinity of Wellfields A and B. A reduction in aquifer pressures caused by abstraction could conceivably change flow paths and potentially affect water quality in the main GAB aquifer. Salinity (or Electrical Conductivity – EC) measurement is the simplest, most robust diagnostic monitoring parameter and is the focus of the monitoring system.
8.1 Monitoring Program Requirements 8.1.1 Purpose • Quantify by routine and appropriate methods, water qualities in all monitoring and production bores on a quarterly basis, as stated in the Indenture. • Identify any changes in EC at bores and springs in the region of either Wellfield A or Wellfield B that may be attributed to abstraction. 8.1.2 Action Triggers • Evidence of water quality change (measured as pH or EC) at GAB springs that can be attributed to water abstraction from Wellfield A or Wellfield B. • Evidence of water quality change (measured as pH or EC) at pastoral or monitor bores that could be attributed to water abstraction from Wellfield A or Wellfield B.
8.2 Results A summary of EC and pH variations during FY10 and the previous reporting period (1 July 2008 to 30 June 2009) is provided in Appendix 5. Large variations in average field water quality can occur at many springs and at some bores from year to year. Such fluctuations, however, generally remained within or close to the historical ranges. As in previous years, statistically significant linear regression coefficients (different from zero at the 95% confidence level) were identified (Figure 8-1). Sites identified by this method, that had a regression coefficient (the slope of a regression line fitted to the dataset) outside the range of -0.1 to 0.1 were then plotted for further analysis. Of the 121 sites, 10 were identified as having such regression coefficients, with all but one indicating increasing salinity. Individual trend graphs for the 11 identified locations are provided in Appendix 6. Data shown in Appendix 5 also include the 5th and 95th percentile values for the historical range of values, and identify where the FY09 average is above the 95th percentile. This method identified a further four locations, also presented in Appendix 6. The majority of identified sites are within the Wellfield A region. This is consistent with the general linear rise in salinity for Wellfield A, discussed in a previous wellfield report (BHP Billiton, 2005) and also reported separately (Snowden Mining Industry Consultants, 2005). It should be noted from the graphs however that correlations for the identified sites, in particular springs, are generally poor.
GROUNDWATER CHEMISTRY PAGE 57 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Clayton Dam (Figure 19-2) has in the past exhibited a strong rising trend particularly influenced by high values in recent years. Other bores in the immediate area exhibit no such trend, suggesting that this is a localised effect, and possibly as a result of bore integrity. Monitoring resumed at the bore in March 2010 following restriction of access by the pastoralist and the trend will continue to be monitored. Indicated salinity increase at GAB15 and GAB15A (Figure 19-5 and Figure 19-6) is believed to be related to abstraction from Wellfield A and has been described and discussed in previous monitoring reports and a consultant report (Woodward-Clyde, 1992). Production from GAB15 was reinstated in late 2001 and has been operated at low rates until June 2005 in an attempt to clear the saline water. Very little salinity data exist beyond that time however, GAB15A shows a similar increasing trend up to December 2007. No data has been collected since this time due to headwork damage at the monitoring bore. Bopeechee HBO007 (Figure 19-1) shows a gradual but inconclusive rising trend that is within the bounds of normal fluctuation. Old Finniss HOF094 (Figure 19-10), West Finniss HWF048 (Figure 19-13) and Old Woman HOW015 (Figure 19-11) also display a gradual rising trend that is highly influenced by seasonal variation and has shown greater data dispersal in recent years. HOW015 in particular displays a high degree of data point scatter and correlation is poor. New Years Gift (Figure 19-8) displays a steady rise with mostly tight grouping of values. A trend of decreasing salinity has been observed at Old Finniss HOF033 (Figure 19-9) however there is a high level of data scatter. Monitoring will continue to observe this trend in FY11. Of the remainder, Wirringina MWI001 (Figure 19-14) is an open pool surrounded by a rock fence on Mundowdna station. Conductivity here can only be measured by placing the probe in the pool and not at the vent, and as such the measurement is heavily influenced by seasonal factors such as rainfall and runoff during wet periods or high evaporation rate during summer months. A rising trend is to be expected given that evaporation is the primary contributing factor. Nevertheless there does appear to be a consistent rising trend for this spring. Of the four sites identified as having an average EC value for FY09 above the 95th percentile of all data available for that site, all four could be considered as showing no distinct trend (GAB8, GAB10, Kopperamanna and Sulphuric HSS012).
PAGE 58 GROUNDWATER CHEMISTRY 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
120
Trend of decreasing conductivity Trend of increasing conductivity
100
80 s e t si f 94 , 0 o 1 5 0 60 F 1 0 er O I 0 b W H W s m O s M 8 u H 4 na n N nni i n a i F0 m W ng d F o 40 i r r H i Ol W s d s l i W , n n 033 5A O007, ft, O 1 Fi F i B t B O s G H e m s
20 H r a W s GA a hee s i c n D 15, Ye nn o i B t w pee A e F o ay d l N G l B C 0 O 0 0 0 0 0 0 0 5 0 0 0 0 0 5 1 3 5 7 9 1 3 9 7 5 3 1 0 ...... 4 0. 0. 0. 0. 0. 1. 1. -0 -0 -0 -0 -0 >1 <-1 Linear regression coefficient of least squares best fit line (value for m where y=mx+b)
Figure 8-1: Frequency distribution of conductivity trends for the wellfields area
GROUNDWATER CHEMISTRY PAGE 59 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
9 GAB WATER USE EFFICIENCY
The efficiency of water use is a significant driver in minimising the impacts of water abstraction from the GAB. Efficient water use practice at the operation and at Roxby Downs is promoted through education and engineering controls. Targets and key performance indicators are developed to promote continuous improvement in water use efficiency. An efficiency rate of 1.24kL/t of ore milled, for a production rate of 200,000 tonnes per annum was anticipated in the 1997 EIS (Kinhill Engineers, 1997). The EIS approval required Olympic Dam to improve efficiency of water use and supply practices.
9.1 Monitoring Program Requirements 9.1.1 Purpose • Measure the water use efficiency within the Process Plant and Roxby Downs town. • Quantify by routine and appropriate methods total water quantities withdrawn from any wellfield on both an individual well and wellfield basis with abstraction added to the record on a monthly basis, as stated in the Indenture. • Provide a 10-year forward schedule for abstraction of groundwater from the Great Artesian Basin. 9.1.2 Deliverable(s) • Collation of domestic and industrial water use efficiency data to assess continuous improvement targets. • 10-year water use schedule to be submitted to the Minister of Water Resources by 1 January annually.
9.2 Results For the FY10 period, the use of high quality water from the GAB averaged 1.39kL/tonne material treated, above the target of 1.12kL/tonne. The variance to target was driven by the substantial impact to ore production, and subsequently hydrometallurgical processing, due to the failure of the Clark Shaft in October 2009. Domestic water use during FY10 averaged 2.35ML/d, down from 2.50ML/d in FY09. The 10-year water use schedule is presented in APPENDIX 7.
PAGE 60 GAB WATER USE EFFICIENCY 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
10 RESOURCE SUSTAINABILITY AND MANAGEMENT
10.1 Historical Perspective In the Wellfield A area spring flow rates have now been approximately stable for about ten years. Abstraction rates from Wellfield A have declined since 1996 (subsequent to the start-up of Wellfield B) and remained stable at around 6ML/day between 2001 and 2003. Rates have been declining steadily since 2005 and have been stable over the last few years at approximately 4.5ML/d (Table 4-1). In October 2009 the failure of the Clark Shaft reduced the demand for water and the average abstraction was 2.3ML/d. For Wellfield B, the average annual abstraction rate was also affected by the failure of the Clark Shaft. With the exception of FY10 rates have remained relatively stable over the last five years and it is expected that this will resume in the future. Drawdown at the corners of the Wellfield B SWL designated area remains less than 5m, with maximum drawdown being 3.6m at the north-east corner near D2. Interpreted drawdown contours for Wellfield B show the drawdown pattern generally conforms to drawdown as presented in the EIS. Drawdown is higher toward the south- east corner of the wellfield area, whilst in general drawdown to the south west of Wellfield B toward the springs zones remains substantially less than predictions presented in the expansion EIS. Management of the impacts of Wellfield B cannot be in isolation of other users and during the past year OD has continued involvement with local and regional GAB stakeholder groups, including the Great Artesian Basin Coordinating Committee and the South Australian Arid Lands Natural Resource Management Board.
10.2 Further Exploration and Development At present there is no further requirement for wellfield exploration or development to supply additional capacity to the operation, as the preferred option for additional water supply to support expanded mining and mineral processing is a coastal desalination plant.
10.3 Future Perspective The 10-year forecast (APPENDIX 7) predicts wellfield abstraction to rise incrementally to 37.4ML/day by 2013 and remain at that level into the future. Abstraction rates for Wellfield A are expected to remain stable at an annual average of 6.0ML/d from 2013 and 31.4ML/d for Wellfield B.
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11 WELLFIELDS INVESTIGATIONS AND TECHNICAL WORKS PROGRAM
Minister Weatherill’s letter of 10/07/2009 (Appendix 8) refers to a Technical Works Program for BHP Billiton. The program requires BHP Billiton to enhance its existing hydrogeological understanding, monitoring and model by means of review and improvement as required. This section briefly summarises progress to date and highlights the challenges ahead. Individual tasks have been addressed by various BHP Billiton reports, as detailed in Table 11-1, with those addressing tasks 2 to 7 currently being reviewed by CSIRO on behalf of the Minister.
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Table 11-1: BHP Billiton Reports Relevant to the Technical Works Program
No. Task Report 1 Installation of four new Golder Associates, July 2010. GAB Monitoring Bore monitoring bores Project, Drilling Completion Report, July 2010. 2 Increased monitoring of GABTWG December 2009. A Review of Reference Jackboot Bore and new Pressures and Monitoring of the Olympic Dam Wellfields. monitoring bores Draft Report.
GABTWG March 2010. Jackboot Bore–Additional Information. Draft Report.
Golder Associates, July 2010. GAB Monitoring Bore Project, Drilling Completion Report, July 2010. 3 Undertake a review of GABTWG March 2010. Hydrostratigraphy of the South- existing structural geology West Great Artesian Basin. Draft Report. and seismic information GABTWG December 2009. Recommendation to Remove the Wellfield A Action Trigger at Jackboot Bore. Draft Report.
GABTWG April 2010. History of Technical Improvement, Olympic Dam Wellfields. Draft Report. 4 Conduct new seismic work N/A (if required) 5 Enhance existing GABTWG April 2010. History of Technical Improvement, hydrogeological model Olympic Dam Wellfields. Draft Report.
GABTWG May 2010. Revised conceptual model of the Olympic Dam Wellfields - ODEX6. Draft Report. 6 Review reference GABTWG December 2009. A Review of Reference pressures for all Pressures and Monitoring of the Olympic Dam Wellfields. compliance monitoring Draft Report. wells 7 Identify alternative Work in progress. monitoring point(s) for Wellfield A and B or recommend new drawdown action triggers for existing monitoring points 8 Develop a proposal for Work in progress. ongoing sustainable management of BHP Billiton’s extractions from the GAB Notes: • GABTWG = GAB Technical Working Group, BHP Billiton
11.1 Installation of Four New Monitoring Bores In FY10 BHP Billiton completed four new monitoring bores (MB5 – 8) to enhance the existing groundwater monitoring infrastructure associated with groundwater abstraction from Wellfield B in the GAB (Figure 11-1):
WELLFIELDS INVESTIGATIONS AND TECHNICAL WORKS PROGRAM PAGE 63 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
• MB5 replaced the dysfunctional MB4 monitoring bore. • MB6 is to monitor head near the western GAB springs. • MB7 and MB8 are to monitor drawdown from Wellfield B. All four bores have already provided new information on the structure and hydraulic characteristics of the GAB aquifer. The bores range between 250 and 722m deep and are equipped with vibrating wire and temperature sensors to monitor pore pressure and temperature at six different depths each.
11.2 Increased Monitoring of Jackboot Bore and the New Monitoring Bores 11.2.1 Concurrent Monitoring of Jackboot Bore and the New Wells BHP Billiton summarised the results of monitoring the Jackboot Bore in a draft report1 currently reviewed by CSIRO on behalf of the Minister. There are several issues or suspected issues with Jackboot Bore, including construction and maintenance, partial penetration of the aquifer, reliability of pressure measurements, uncertainty in the drawdown estimation, hydraulic response of the bore vs. aquifer, recovery and the integrity of the bore vs. data. The draft report highlighted the influence of antecedent pastoral flows on the measured pressure and a short summary is presented below. Up to mid-2009 it was believed that antecedent pastoral flow (between 2 – 3.3L/s) did not have a significant influence on the measured shut-in pressures at Jackboot Bore. Since May 2009 the antecedent pastoral flow was reduced; and in December 2009 eliminated at Jackboot. Shut-in pressures (SIP) corresponding to the reduced pastoral flows since May 2009 have significantly increased (by some 20kPa or 2m) with a corresponding decline in drawdown. Prior to December 2009, the bore was shut in for 30 minutes every time before SIP was measured. In BHP Billiton’s interpretation, the SIP has increased during the 30 minute period, but has not fully recovered from the effects of pastoral flow. Measured pressures and temperature-inclusive groundwater heads for ‘cold’ measurements (shut-in and no antecedent flow), available for the new bores MB5 to MB8 in the corresponding FY10 period, indicate remarkably stable groundwater heads. These data, in particular from MB7 and MB8, (situated between Wellfield B and Jackboot Bore), suggest that groundwater heads west of Wellfield B have remained stable throughout FY10. The significant changes measured at Jackboot are therefore most likely to have been caused by antecedent pastoral flow. Since pastoral flow was eliminated, the pressure has increased and the drawdown has decreased to ~ 2.5m (from the 3.9m drawdown reported in the FY09 GAB Wellfield Report). It also appears that this 2.5m drawdown, (without the antecedent pastoral flow) corresponds to the drawdown predicted by the ODEX6 model. It is anticipated that the head at Jackboot Bore will stabilise in the remaining six-month period (of the 12 months concurrent monitoring specified by the Minister) and will show similar trends to those from MB5 to MB8.
1 GABTWG March 2010. Jackboot Bore–Additional Information. Draft Report.
PAGE 64 WELLFIELDS INVESTIGATIONS AND TECHNICAL WORKS PROGRAM 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT 11.2.2 The Monitoring of the New Bores to Determine the Extent of Regional Drawdown Groundwater heads for artesian bores are the sum of the elevation of the well-head and groundwater pressure. Groundwater head is subtracted from a ‘Practical Reference Pressure’ or PRP to estimate drawdown due to groundwater abstraction from Wellfield B. For bores that were drilled in FY10, long after the 1996 commissioning of Wellfield B, the PRPs and subsequently drawdown may be estimated the as the difference between estimated heads in 1996 and 2010. The recommended preliminary Practical Reference Heads (PRHs) for MB5 to MB8 are listed in Table 12-2. PRHs were used instead of PRPs because groundwater heads in MB5-8 are based on ‘cold’ (shut-in wellhead, no antecedent flow) pressures and consequently temperature-inclusive groundwater heads were calculated. It must be emphasised that the preliminary PRHs represent the best understanding of reference heads for MB5-8 in 2010; and as such they may not be perfect and may need further reviews and improvements. In particular, PRHs for MB5-8 may change once more initial head data become available.
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Table 12-2: Groundwater Head in MB5-8 and Preliminary PRHs
Site Date Estimated Head Calculated Head, Preliminary PRH, ~1996, m AHD, A 2010, m AHD, B m AHD MB5 18/12/2009 75-76 76.6 76 MB5 8/02/2010 75.7 MB5 8/02/2010 75.9 MB5 11/03/2010 76.0 MB5 28/04/2010 76.2 MB5 26/05/2010 75.9 MB5 23/06/2010 76.1 MB6 18/12/2009 76-77 75.5 76 MB6 8/02/2010 75.5 MB6 8/02/2010 75.4 MB6 11/03/2010 75.9 MB6 28/04/2010 76.1 MB6 26/05/2010 76.0 MB6 23/06/2010 76.1 MB7 27/01/2010 87 80.0 87 MB7 27/01/2010 81.6 MB7 11/03/2010 82.0 MB7 28/04/2010 82.1 MB7 26/05/2010 81.9 MB7 23/06/2010 82.5 MB8 27/01/2010 88 78.0 88 MB8 27/01/2010 79.2 MB8 11/03/2010 80.3 MB8 28/04/2010 80.2 MB8 26/05/2010 80.3 MB8 23/06/2010 80.9
11.3 Undertake a Review of Existing Structural Geology and Seismic Information The objective of the review was to create representative, correct and documented surfaces for the main hydrostratigraphic units of the GAB: the land surface, the Bulldog Shale, the main GAB aquifer, and the hydraulic basement. These surfaces are based on both drillhole and geophysical data and may be used for subsequent numerical modelling. Drillhole data were obtained between longitudes 134.5 and 142.5 and latitudes -23.5 to -31.0. This area extends beyond the boundaries of South Australia (SA) to the Northern Territory (NT) and Queensland (QLD). Drillhole data and hydrostratigraphic information were obtained, processed and interpreted from various sources, including BHP Billiton’s own data, state government agencies and GAB hydrogeological publications.
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The paucity of drillhole data in some areas provided significant challenges to accurately defining surfaces. Therefore all available information, that may improve spatial resolution, has been incorporated. Geophysical data, in particular seismic, filled-in large gaps in drilling data in some parts of the GAB. BHP Billiton engaged a consultant to interpret seismic data. The interpretation of seismic reflectors was based on the established relationship between the top of the GAB Aquifer (C Horizon) and the hydraulic basement (Z Horizon). This relationship has already been successfully used to delineate fine structures near Wellfield A and in the Cooper Basin. The combined hydrostratigraphy- seismic data were processed and documented using ArcGIS. Data from MB5 and MB6 suggest the existence of a structural discontinuity between Jackboot Bore and MB5. Such structure is probably the reason why Jackboot Bore has not significantly been affected by Wellfield A abstractions; conversely such structure may restrict the propagation of drawdown from Wellfield B to the west. Groundwater head/drawdown evidence also supports the structural and hydraulic isolation of Jackboot Bore from Wellfield A2. Jackboot Bore is in the hydraulic ‘shadow’ of the Hermit Fault and basement structure that separates the North-East Sub-Basin from the open GAB (where Wellfield B is situated).
11.4 Conduct New Seismic Work (if required) Because of the adequate results obtained from the review of existing structural geology and seismic information (Section 11.3) this task was considered unnecessary.
11.5 Enhance the Existing Hydrogeological Model Considerable work has been done to enhance the existing hydrogeological model. The model was extended to the west of Wellfield B to cover the western springs area (Figure 11-1; west of the new monitoring bores MB5 and MB6). The model grid between the new area and Jackboot Bore was refined. Western Springs were inserted and spring flows were calibrated. Western drain cells (Layer Two) were inserted and drain elevations were imported from a Digital Terrain Model. Monitoring and groundwater abstraction data were all updated and findings of the recent hydrostratigraphic and geophysics work (Section 11.3) were included in the extended western area. Considerable documentation of the model was also completed. The immediate challenges include calibration near MB5 and improving the understanding of the role the Cadna-owie Formation plays in Layer Three.
11.6 Review the Reference Pressures for all Compliance Monitoring Wells Following a discussion about revising the PRP for Jackboot Bore, DWLBC suggested a review of all PRPs for Wellfield B, not just the compliance points. This recommendation was supported and implemented by BHP Billiton and most have not actually been reviewed since being established in 1996. Accordingly, a review of two compliance sites for Wellfield A (GAB8 and HH2) and all sites for Wellfield B has been completed and documented. The existing PRPs were established prior to Wellfield B production in 1996. In some cases the original PRPs were based on a few, or even on a single pressure measurement. In the review, periods post 1996, with more and better quality measurements, were also used if
2 GABTWG December 2009. Recommendation to Remove the Wellfield A Action Trigger at Jackboot Bore. Draft Report
WELLFIELDS INVESTIGATIONS AND TECHNICAL WORKS PROGRAM PAGE 67 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT drawdown from Wellfield B was not evident. As a consequence, different time periods may have been used for different bores to delineate the best PRP. For bores situated closer to Wellfield B measurements prior or close to the time of commissioning were used. For sites further from Wellfield B, however, data from even the early 2000s were used if not affected by abstraction from Wellfield B. A total eight out of reviewed 21 PRPs bores for Wellfield B were recommended to be changed. Of the eight recommendations, five were to increase the PRPs that will cause higher calculated drawdowns. The largest changes were recommended at Charles Angus, Peters and OB1 (29, 18 and 15 kPa, respectively). PRPs were recommended to be decreased at D3, D2 and Jackboot (-23, -10 and -6 kPa, respectively). The changes, if implemented, would provide a more comprehensive drawdown map and eliminate the reported negative drawdowns. Data from Morris Creek, Brolga (Highway), MB1, Sinclair, Peters and Boocaltaninna bores were recommended to be added to the existing bores for the estimation of drawdown from Wellfield B. A further investigation was recommended for Callanna 2, Cooranna and Maynards to determine appropriate PRPs. Three bores (HH1, HH3 and HH4), used for the calculation of drawdown from Wellfield A, were also recommended to be used for Wellfield B. With the proposed new monitoring bores MB5, MB6, MB7 and MB8 the total number of bores, to be used to create a drawdown map for Wellfield B, could be 37; a 76% increase on the 21 bores used for the current drawdown map (Figure 6-1). The improved set of monitoring bores to be used for the calculation of drawdown would provide an extensive network of monitoring sites for a more reliable estimation of drawdown in ecologically significant areas: to the west and south of Wellfield B. In particular, the arc of sites used for drawdown mapping, from MB6 via MB5, MB1, HH1, HH2, HH4 to Brolga (Highway) bore (Figure 11-1) would add more certainty to BHP Billiton’s monitoring program.
PAGE 68 WELLFIELDS INVESTIGATIONS AND TECHNICAL WORKS PROGRAM 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Figure 11-1: Recommended Bores for the Delineation of Drawdown
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1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
11.7 Identify alternative monitoring point(s) for Wellfield A and B or recommend new drawdown action triggers for existing monitoring points This is work in progress.
11.8 Develop a proposal for ongoing sustainable management of BHP Billiton’s extractions from the GAB This is work in progress.
11.9 Discussion BHP Billiton has undertaken a complete review of monitoring near Wellfield B and identified several ways to improve monitoring: 1. By increasing the number of sites. The draft report entitled “A Review of Reference Pressures and Monitoring of the Olympic Dam Wellfields” identified and recommended an extensive network of monitoring sites for a more reliable estimation of drawdown in ecologically significant areas: to the west and south of Wellfield B. In particular, the arc of sites, to be used to create a drawdown map for Wellfield B, from MB6 via MB5, MB1, HH1, HH2, HH4 to Brolga (Highway) bore (Figure 11-1) would add more certainty to BHP Billiton’s monitoring program. The draft report recommends using a total of 37 bores for the calculation of drawdown; a 76% increase on the 21 bores used for the 2010 drawdown map. 2. By improving the quality of drawdown calculation. The draft report entitled “A Review of Reference Pressures and Monitoring of the Olympic Dam Wellfields” recommended a total of eight (out of 21) practical reference pressures (PRPs) for Wellfield B to be changed. The changes, if implemented, would provide a more comprehensive drawdown map and eliminate the reported negative drawdowns. 3. By collecting new types of data to improve the hydrogeological understanding. The new monitoring bores MB5 – 8 will provide pore pressure (groundwater head) and temperature data from various depths. This data, not available from ordinary monitoring bores or pastoral wells, will enhance the understanding of vertical groundwater movements and diffuse discharge; both being crucial to the understanding of GAB groundwater budgets and spring flows. The temperature data have already provided vital information on the temperature distribution with depth – these in turn were used to calculate temperature- inclusive groundwater heads and can improve drawdown estimates. 4. By recognising emerging issues. Temperature and antecedent-flow induced changes in groundwater head may pose a complex problem that will need to be solved to ensure that drawdowns calculated at different sites are fully comparable. BHP Billiton’s future aim is to change as many bores as possible to the “cold shut-in” process (measure gauge pressure on arrival) and measure the temperature of the water at the wellhead to improve the calculation of groundwater heads and drawdown. This is an emerging issue and unique to the GAB as groundwater temperatures in most artesian basins do not significantly alter groundwater heads. It is the combination of high temperatures (> 60 ºC) and the depth of the aquifer (north of Wellfield B > 700 m) that makes the calculations of GAB groundwater heads and drawdown challenging.
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11.10 Summary and Conclusions Four new monitoring bores have been completed and the new data from these bores have already provided new information on the structure and hydraulic characteristics of the GAB aquifer. The bores, between 250 and 722 m deep, are also equipped with vibrating wire and temperature sensors to monitor pore pressure and temperature at six different depths each. BHP Billiton has undertaken a complete review of monitoring near Wellfield B and identified several ways to improve monitoring. Monitoring procedures and the quantity and quality of pressure measurements and drawdown estimation have continuously been improved. The focus of monitoring has also changed from wellfield performance through drawdown to one of aquifer sustainability. BHP Billiton engaged a consultant to interpret seismic data near Wellfield B and completed an in-house review of all hydrostratigraphic (drillhole) data between longitudes 134.5 and 142.5 and latitudes -23.5 to -31.0. This area extends beyond the boundaries of South Australia (SA) to the Northern Territory (NT) and Queensland (QLD). Drillhole data and hydrostratigraphic information were obtained, processed and interpreted from various sources, including BHP Billiton’s own data, state government agencies and GAB hydrogeological publications. The combined hydrostratigraphy- seismic data were processed and documented using ArcGIS. The existing flow model was extended to the west of Wellfield B to cover the western springs area west of the new monitoring bores MB5 and MB6. The model grid between the new area and Jackboot Bore was refined. Western Springs were inserted and spring flows were calibrated. Western drain cells (Layer Two) were inserted and elevations imported from a Digital Terrain Model. A review of groundwater monitoring, including Practical Reference Pressures (PRPs) for two compliance sites for Wellfield A and all sites for Wellfield B has been completed and documented. A total eight out of 21 PRPs for monitoring bores for Wellfield B were recommended to be changed. Data from seven bores were recommended to be added to the existing network of bores for the estimation of drawdown from Wellfield B. A further investigation was recommended for three bores to determine appropriate PRPs. Three further bores, used for the calculation of drawdown from Wellfield A, were also recommended to be used for Wellfield B. The improved set of monitoring bores to be used for the calculation of drawdown would provide an extensive network of monitoring sites for a more reliable estimation of drawdown to the ecologically significant areas: to the west and south of Wellfield B. As a result of approximately 30 years of investigations and monitoring, the hydrogeology of the south-west GAB is probably the best understood in the entire GAB. BHP Billiton also leads the way in identifying issues specifically related to the GAB, including conceptual hydrogeology in the south-west GAB, methodology for groundwater monitoring, temperature effects on drawdown, understanding the quality and uncertainty relating to pressure measurements, and addressing sustainability.
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12 RECOMMENDATIONS
• The annualised average abstraction rate from Wellfield A should continue to be maintained at or below 6.0ML/d. • Continue improvements for drawdown estimation around wellfield B by converting selected bores to cold shut in measurements.
RECOMMENDATIONS PAGE 73 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
13 REFERENCES
ABARE, AGSO and BRS 1996, ‘Lake Eyre Basin: An Economic and Resource Profile of the South Australian Portion’, ABARE Research Report 96.1, Canberra. AGC 1982, ‘Olympic Dam Project, Groundwater Supply Investigations’, unpublished report. AGC 1987, ‘Olympic Dam Water Supply, Wellfield A Construction’, unpublished report. BHP Billiton 2005, ‘Interim Great Artesian Basin Wellfields Report 1 July 2004 – 30 June 2005’, BHP Billiton Report ODENV029 BHP Billiton 2006, ‘Great Artesian Basin Wellfields Report 1 July 2005 – 30 June 2006’, BHP Billiton Report ODENV033. BHP Billiton 2009a, ‘Monitoring Program – Great Artesian Basin (GAB) FY10’, Olympic Dam Document No. 2789. BHP Billiton 2009b, ‘Monitoring Program – Flora FY10’, Olympic Dam Document No. 2664. Geoscience Australia 2009, Place name search, http://www.ga.gov.au/map/names, accessed 03/09/2009. Golder Associates 1997, ‘Great Artesian Basin Groundwater Use Survey for Wellfield B’, Golder Associates Pty Ltd, Perth. Habermehl, MA 1980, ‘The Great Artesian Basin, Australia’, BMR Journal of Australian Geology and Geophysics, 5. Habermehl, MA 1982, ‘Springs in the Great Artesian Basin – their origin and nature’, Report 235, Bureau of Mineral Resources, Geology and Geophysics, Australian Government Publishing Service, Canberra. Habermehl, MA 1983, ‘Hydrogeology and Hydrochemistry of the Great Artesian Basin, Australia’, Proc. Int. Conf. on Groundwater and Man, Sydney. Kinhill Engineers 1995, ‘Olympic Dam Operations Survey and Assessment Report Supplementary Environmental Studies Borefield B Development’, Kinhill Engineers Pty Ltd, Parkside, SA. Kinhill Engineers 1997, ‘Olympic Dam Expansion Project, Environmental Impact Statement’, Kinhill Engineers Pty Ltd, Adelaide. Kinhill Stearns 1984, ‘Olympic Dam Project Supplementary Environmental Studies Mound Springs’, Kinhill Stearns, Adelaide. Kinhill-Stearns Roger 1982, ‘Olympic Dam Project, Draft Environmental Impact Statement’, Kinhill-Stearns Roger, Adelaide. Land Use Consultants 2009, ‘Mound Spring Monitoring of the Lake Eyre South Region October 2009’, Land Use Consultants, Clare. Land Use Consultants 2010, ‘Mound Spring Monitoring of the Lake Eyre South Region April 2010’, Land Use Consultants, Clare. Roxby Downs (Indenture Ratification) Act 1982 Snowden Mining Industry Consultants 2005, ‘WMC Resources Ltd Olympic Dam Great Artesian Basin Wellfield A – Analysis of Salinity Trends February 2005 Project Number 4965’, Snowden Mining Industry Consultants (Pty) Ltd, Perth.
PAGE 74 REFERENCES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
Welsh 2000, ‘GABFLOW: A Steady State Groundwater Flow Model of the Great Artesian Basin’, Bureau of Rural Sciences, Canberra. WMC 1995, ‘Hydrogeological Investigation and Numerical Modelling, Lake Eyre Region, Great Artesian Basin’, unpublished WMC Report HYD T044. WMC 1997, ‘Olympic Dam Operation, Borefield B Development, Bore Completion Report’, unpublished WMC Report HYD T065. WMC 1998, ‘Olympic Dam Operations – Water Supply Borefields – Reference Pressures for Monitor Bores’, WMC Report HYD T103. WMC 2002, ‘Great Artesian Basin Wellfields: Abstraction history and aquifer response for the period March 2001 to February 2002’, WMC Report HYD T219. WMC 2004, ‘Great Artesian Basin Wellfields Report 1 January 2003 – 31 December 2003’, WMC Report ODCENV018. Woodward-Clyde 1992, ‘Assessment of mechanisms causing a salinity increase at GAB 15’, Woodward-Clyde, Hackney.
REFERENCES PAGE 75 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
14 APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10
SIP/SWL Flow Pressure Flow Rate Quality Category Comments Site Required Actual Required Actual Required Actual Required Actual Beatrice Bore HBS004 LUC 2 2 2 2 Boocaltaninna PA 1 1 1 1 1 1 1 1 Bopeechee HBO004 LUC 2 2 2 2 Bopeechee HBO007 LUC 2 2 2 2 Bopeechee HBO011 LUC 2 2 2 2 Bopeechee Bore HBO013 PA 1 4 1 4 1 4 Callanna PA 1 1 1 - 1 1 1 1 Insufficient pressure for FP Cannuwaukaninna PA 1 - 1 1 1 1 1 1 Could not shut in Chapalana PA 1 1 1 1 1 1 1 1 Charles Angus PA 1 1 1 - 1 1 1 1 Insufficient pressure for FP Clayton #1 PA 1 1 1 1 1 1 Clayton #2 PA 1 1 1 1 1 1 Clayton Dam PA 1 2 1 2 1 2 1 2 Closed system. FP and FR Cooranna PQ 4 4 4 - 4 - 4 4 not relevant. Cooryaninna PA 1 1 1 1 1 1 1 1 Coward CBC001 LUC 2 2 2 2 Coward CBC002 LUC 2 2 2 2 Coward CBC013 LUC 2 2 2 2 D2 MQ 4 6 4 5 4 5 Constant flow rate D3 MQ 4 5 4 5 4 5 Constant flow rate Davenport WDS001 LUC 2 2 2 2
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SIP/SWL Flow Pressure Flow Rate Quality Category Comments Site Required Actual Required Actual Required Actual Required Actual Davenport WDS042 LUC 2 2 2 2 Davenport WDS052 LUC 2 2 2 2 Dead Boy HDB004 LUC 2 2 2 2 Dead Boy HDB005 LUC 2 2 2 2 Dulkaninna PA 1 1 1 1 1 1 1 1 Emerald LES001 LUC 2 2 2 2 Fred LFE001 LUC 2 2 2 2 Fred LFE006 LUC 2 2 2 2 Frome Creek PA 1 - 1 1 Bore not flowing Access was not permitted due to safety risk – this has GAB1 MQ 4 2 4 2 now been addressed and monitoring has resumed GAB2 SubQ 4 - Bore flowing GAB5 MQ 4 - 4 - Bore damaged GAB5A MQ 4 1 4 1 See GAB1 comment Production bore – can only GAB6 ProdAQ Continuous 4 2 measure quality when bore is turned on GAB6A MQ 4 2 4 2 See GAB1 comment GAB7 MQ 4 2 4 2 See GAB1 comment GAB8 MQ 4 2 4 2 See GAB1 comment GAB10 MQ 4 2 4 2 See GAB1 comment GAB11 MQ 4 2 4 2 See GAB1 comment GAB12 ProdAQ Continuous 4 2 See GAB6 comment
APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10 PAGE 77 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SIP/SWL Flow Pressure Flow Rate Quality Category Comments Site Required Actual Required Actual Required Actual Required Actual GAB12A MQ 4 2 4 2 See GAB1 comment GAB13A SubQ 4 2 See GAB1 comment Production bore – can only GAB14 ProdAQ Continuous 4 - measure quality when bore is turned on GAB14A MQ 4 2 See GAB1 comment Production bore – can only GAB15 ProdAQ Continuous 4 - measure quality when bore is turned on GAB15A MQ 4 - 4 - Bore damaged Production bore – can only GAB16 ProdAQ Continuous 4 2 measure quality when bore is turned on GAB16A MQ 4 2 4 2 See GAB1 comment GAB17 SubQ 4 - Bore flowing Production bore – can only GAB18 ProdAQ Continuous 4 - measure quality when bore is turned on GAB18A SubQ 4 2 See GAB1 comment GAB19 MQ 4 2 4 2 See GAB1 comment GAB21 SubQ 4 2 See GAB1 comment GAB22 SubQ 4 2 See GAB1 comment GAB23 SubQ 4 - Bore flowing GAB24 MQ 4 2 4 2 See GAB1 comment GAB30A MQ 4 2 4 2 See GAB1 comment GAB31A MQ 4 2 4 2 See GAB1 comment
PAGE 78 APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SIP/SWL Flow Pressure Flow Rate Quality Category Comments Site Required Actual Required Actual Required Actual Required Actual GAB33A MQ 4 1 4 1 See GAB1 comment GAB51 ProdBQ 4 4 Continuous 4 4 Production bore GAB52 ProdBQ 4 4 Continuous 4 4 Production bore GAB53 ProdBQ 4 4 Continuous 4 4 Production bore FR only measured annually PQ 4 4 4 4 1 4 4 Georgia as no change during year. Gosse LGS002 LUC 2 2 2 2 Gosse LGS004 LUC 2 2 2 2 Hermit Hill HHS028 LUC 2 2 2 2 Hermit Hill HHS035 LUC 2 2 2 2 Hermit Hill HHS101 LUC 2 2 2 - Zero flow Hermit Hill HHS125A LUC 2 2 2 2 Hermit Hill HHS137 LUC 2 2 2 2 Hermit Hill HHS170 LUC 2 2 2 2 HH1 MQ 4 2 4 2 HH2 MQ 4 2 4 2 HH3 SubQ 4 2 HH4 MQ 4 2 4 2 Highway PA 1 1 1 1 Bore no longer flowing so FP PQ 4 10 4 4 4 2 4 10 Jackboot and FR not required. Jewellery Creek PA 1 1 1 1 1 1 1 1 Kopperamanna PA 1 1 1 1 1 1 Lake Billy #2 PQ 4 4 4 4 4 4
APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10 PAGE 79 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SIP/SWL Flow Pressure Flow Rate Quality Category Comments Site Required Actual Required Actual Required Actual Required Actual Lake Harry PA 1 1 1 1 1 1 1 1 Marion PA 1 1 1 1 1 - 1 1 Assumed unchanged Closed system. FP and FR Maynards PA 1 1 1 - 1 - 1 1 not relevant. MB1 MQ 4 4 4 4 MB2 SubQ 4 4 McLachlan LMS004B LUC 2 2 2 2 Morphetts PA 1 1 1 1 1 1 1 1 Morris Creek PA 1 1 1 - 1 1 1 1 Insufficient pressure for FP Muloorina PA 1 1 1 1 1 1 1 1 New Years Gift PQ 4 2 4 2 See GAB1 comment OB1 MQ 4 4 4 4 OB3 MQ 4 4 4 4 OB6 MQ 4 4 4 4 Old Finniss HOF004 LUC 2 2 2 2 Old Finniss HOF033 LUC 2 2 2 2 Old Finniss HOF081 LUC 2 2 2 2 Old Finniss HOF094 LUC 2 2 2 2 Old Finniss HOF096 LUC 2 2 2 2 Old Woman HOW009 LUC 2 2 2 2 Old Woman HOW015 LUC 2 2 2 2 Old Woman HOW025 LUC 2 2 2 2 Peachawarrina PA 1 1 1 1 1 1 Peters PQ 4 4 4 4 4 4 Closed system FP and FR
PAGE 80 APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SIP/SWL Flow Pressure Flow Rate Quality Category Comments Site Required Actual Required Actual Required Actual Required Actual not relevant. S1 MQ 4 4 4 4 S2 MQ 4 4 4 4 S3 MQ 4 4 S3A MQ 4 4 4 4 S4 MQ 4 4 4 4 4 - 4 4 Constant flow rate Closed system FP and FR S5 MQ 4 4 4 4 4 4 not relevant. Sinclair PA 1 1 1 1 1 1 1 1 Sulphuric HSS011 LUC 2 2 2 2 Sulphuric HSS012 LUC 2 2 2 2 Sulphuric HSS024 LUC 2 2 2 2 No access permitted prior to Tarkanina #2 PQ 4 2 4 2 4 2 4 2 March 2010 Tent Hill 2 PQ 4 4 Two Mile #2 PQ 4 4 Venables SubQ 4 - 4 Bore flowing No access in September WCB1 MQ 4 3 4 2009 WCB2 MQ 4 4 4 4 Welcome WWS001 LUC 2 2 2 2 Welcome WWS002 LUC 2 2 2 2 Welcome WWS004 LUC 2 2 2 2 Welcome WWS013 LUC 2 2 2 2 Well Creek #2 PQ 4 4 4 4
APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10 PAGE 81 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SIP/SWL Flow Pressure Flow Rate Quality Category Comments Site Required Actual Required Actual Required Actual Required Actual West Finniss HWF002 LUC 2 2 West Finniss HWF003 LUC 2 2 2 2 West Finniss HWF048 LUC 2 2 2 2 Wirringinna Spring MWI001 PQ 4 4 4 4 Yarra Hill PA 1 2 1 2 1 1 2 Notes: • Categories are defined in BHP Billiton 2009a.
PAGE 82 APPENDIX 1: SUMMARY OF MONITORING RECORDS FOR FY10
BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
15 APPENDIX 2: CALIBRATION CERTIFICATES FOR DRUCK PRESSURE TRANSDUCERS
PAGE 84 APPENDIX 2: CALIBRATION CERTIFICATES FOR DRUCK PRESSURE TRANSDUCERS 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
APPENDIX 2: CALIBRATION CERTIFICATES FOR DRUCK PRESSURE TRANSDUCERS PAGE 85 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
16 APPENDIX 3: SUMMARY OF SPRING FLOW DATA FY10
FY10 FY09 Historical range No. of Site average average records 5th 95th (L/s) (L/s) percentile percentile Beatrice Bore HBS004 2 0.1060 0.0700 0.2224 0.7400 Bopeechee HBO004 2 0.4090 0.4500 0.2332 0.6500 Bopeechee HBO007 2 0.0105 0.0117 0.0054 0.0136 Bopeechee HBO011 2 0.0230 0.0216 0.0180 0.1625 Coward CBC001 2 0.3245 0.3053 0.2368 0.6548 Coward CBC002 2 1.9740 2.0262 1.7562 2.2072 Coward CBC013 2 10.6415 9.6252 4.8753 14.0209 Davenport WDS001 2 0.7160 0.7160 0.5360 0.9398 Davenport WDS042 2 0.0320 0.0383 0.0180 0.0518 Davenport WDS052 2 0.0030 0.0037 0.0020 0.0085 Dead Boy HDB004 2 0.0655 0.0693 0.0333 0.0825 Dead Boy HDB005 2 0.0790 0.1009 0.0193 0.1066 Emerald LES001 2 1.4935 1.3525 1.1390 2.2615 Fred LFE001 2 0.1090 0.0970 0.0270 0.1760 Fred LFE006 2 0.0335 0.0302 0.0261 0.0784 Gosse LGS002 2 0.2275 0.2195 0.1596 0.3660 Gosse LGS004 2 1.5480 1.4970 1.1390 1.9401 Hermit Hill HHS028 2 0.0495 0.0360 0.0173 0.0733 Hermit Hill HHS035 2 0.0145 0.0132 0.0100 0.0215 Hermit Hill HHS101 2 0.0000 0.0000 0.0000 0.0020 Hermit Hill HHS125A 2 0.0075 0.0125 0.0045 0.0191 Hermit Hill HHS137 2 0.2265 0.2342 0.1732 0.2927 Hermit Hill HHS170 2 0.3905 0.4185 0.2275 0.6469 McLachlan LMS004B 2 0.8705 0.7135 0.6876 1.2920 Old Finniss HOF004 2 0.0115 0.0105 0.0053 0.0135 Old Finniss HOF033 2 0.0015 0.0010 0.0000 0.0055 Old Finniss HOF081 2 0.0770 0.0670 0.0031 0.0811 Old Finniss HOF094 2 0.0260 0.0172 0.0101 0.0579 Old Finniss HOF096 2 0.2125 0.2150 0.1370 0.1835 Old Woman HOW009 2 0.1075 0.0855 0.0860 0.2345 Old Woman HOW015 2 0.0200 0.0167 0.0149 0.1734 Old Woman HOW025 2 0.0565 0.0472 0.0090 0.0600 Sulphuric HSS011 2 0.2405 0.2543 0.1983 0.3254 Sulphuric HSS012 2 0.0570 0.0575 0.0274 0.0644 Sulphuric HSS024 2 0.0540 0.0466 0.0400 0.0595 Welcome WWS001 2 0.0480 0.0671 0.0386 0.0938
PAGE 86 APPENDIX 3: SUMMARY OF SPRING FLOW DATA FY10 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
FY10 FY09 Historical range No. of Site average average records 5th 95th (L/s) (L/s) percentile percentile Welcome WWS002 2 0.5410 0.5555 0.5243 0.7562 Welcome WWS004 2 0.8945 0.8425 0.6810 0.9980 Welcome WWS013 2 0.0125 0.0105 0.0110 0.0286 West Finniss HWF003 2 0.0730 0.0438 0.0136 0.0679 West Finniss HWF048 2 0.4525 0.4076 0.2706 1.3894
APPENDIX 3: SUMMARY OF SPRING FLOW DATA FY10 PAGE 87 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
17 APPENDIX 4: HISTORICAL SPRING FLOW RATES
SPRING NUMBER : CBC001 fluorometric
0.8 ) 0.7 ond c
e 0.6 s
r 0.5 pe s e
r 0.4 t i l
( 0.3 e t a
R 0.2 w
o 0.1 Fl 0.0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-1: Spring flow rate - CBC001
SPRING NUMBER : CBC002 weir-gauging 3.0
nd) 2.5 o c e s
r 2.0 pe
s
e 1.5 r t i l (
e 1.0 t a 0.5 ow R l F 0.0 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-2: Spring flow rate - CBC002
PAGE 88 APPENDIX 4: HISTORICAL SPRING FLOW RATES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : CBC013 fluorometric
20 )
d 18 n o
c 16 e
s 14 r
pe 12
s e
r 10 t i l
( 8 e t
a 6
R 4 dye-gauging weir-gauging dye-gauging 2 Flow 0 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-3: Spring flow rate - CBC013
SPRING NUMBER : HBO004 weir-gauging
0.8 )
d 0.7 n 0.6 seco
r
e 0.5 s p
e 0.4 r t i l
( 0.3 e t
a 0.2 R
w 0.1 o l F 0.0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-4: Spring flow rate – HBO004
SPRING NUMBER : HBO007 weir-gauging 0.016
) 0.014 d n 0.012 seco
r 0.010 e 0.008 es p r t i
l 0.006 ( e t 0.004 a R
w 0.002 o l
F 0.000 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-5: Spring flow rate - HBO007
APPENDIX 4: HISTORICAL SPRING FLOW RATES PAGE 89 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HBO011 weir-gauging 0.25 nd)
o 0.20 c e s
r 0.15 pe s e r t i
l 0.10 ( e t a
R 0.05 ow l F 0.00 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 198 198 198 198 198 198 198 198 199 199 199 199 199 199 199 199 199 199 200 200 200 200 200 200 200 200 200 200 201 201
Monitoring Period (years)
Figure 17-6: Spring flow rate - HBO011
SPRING NUMBER : HBS004 weir-gauging 0.80 0.70 ond)
c 0.60 e s
r 0.50
pe weir- unknown volumetric s
e 0.40 gauging r t i l
( 0.30 e t
a 0.20 R
ow 0.10 Fl 0.00 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-7: Spring flow rate - HBS004
SPRING NUMBER : HDB004 fluorometric
0.10 ) 0.09 nd
o 0.08 c e
s 0.07 r 0.06 pe s e
r 0.05 t i l 1st injection
( 0.04 e t
a 0.03 R 0.02 2nd injection ow 0.01 Fl 0.00 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-8: Spring flow rate - HDB004
PAGE 90 APPENDIX 4: HISTORICAL SPRING FLOW RATES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HDB005 fluorometric
0.35 ) d
n 0.30 co
se 0.25
r e p 0.20 s e r t i l 0.15 ( e t
a 0.10 R w
o 0.05 l F 0.00 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2
Monitoring Period (years)
Figure 17-9: Spring flow rate - HDB005
SPRING NUMBER : HHS028 weir-gauging 0.10 ) d
n 0.08 seco
r
e 0.06 es p r t i
l 0.04 (
e t a
R 0.02 w o l F 0.00 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2
Monitoring Period (years)
Figure 17-10: Spring flow rate – HHS028
SPRING NUMBER : HHS035 weir-gauging 0.030 ) 0.025 ond c e s
0.020 r pe
s 0.015 e r t i l
( 0.010 e t a
R 0.005 w o
Fl 0.000 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 198 198 198 198 198 198 198 198 199 199 199 199 199 199 199 199 199 199 200 200 200 200 200 200 200 200 200 200 201 201
Monitoring Period (years)
Figure 17-11: Spring flow rate – HHS035
APPENDIX 4: HISTORICAL SPRING FLOW RATES PAGE 91 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HHS101 weir-gauging 0.004 ) ond
c 0.003 e s
r pe
s 0.002 e r t i l ( e t
a 0.001 R ow
Fl 0.000 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-12: Spring flow rate – HHS101
SPRING NUMBER : HHS125 weir-gauging 0.025
0.020 ond) c e s r 0.015 pe s e r t i
l 0.010 ( e t a R
0.005 ow
Fl 0.000 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2
Monitoring Period (years)
Figure 17-13: Spring flow rate – HHS125
SPRING NUMBER : HHS137 weir-gauging 0.6
0.5 ond) c e s 0.4 r pe
s 0.3 e r t i l (
e 0.2 t a
R 0.1 w o Fl 0.0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-14: Spring flow rate – HHS137
PAGE 92 APPENDIX 4: HISTORICAL SPRING FLOW RATES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HHS170 weir-gauging 0.8 )
d 0.7 weir-gauging
n dye-gauging 0.6 seco r
e 0.5 p
s 0.4 e r t i l
( 0.3 e t
a 0.2 R w
o 0.1 l F 0.0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-15: Spring flow rate – HHS170
SPRING NUMBER : HOF004 weir-gauging 0.020 0.018 0.016 dye-gauging weir-gauging ond) c
e 0.014 s r 0.012 pe
s 0.010 e r t
i 0.008 l 2nd injection (
e 0.006 t a
R 0.004 1st injection
ow 0.002 Fl 0.000 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-16: Spring flow rate – HOF004
SPRING NUMBER : HOF033 weir-gauging
0.008 0.007 ond)
c 0.006 e s r 0.005 pe
s 0.004 e r t i l 0.003 ( e t
a 0.002 R
0.001 ow
Fl 0.000 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-17: Spring flow rate – HOF033
APPENDIX 4: HISTORICAL SPRING FLOW RATES PAGE 93 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HOF081 weir-gauging 0.40 )
d 0.35 n 0.30 eco s
r 0.25 e
s p 0.20 e r t i l
( 0.15
e t
a 0.10 R
w 0.05 o l F 0.00 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-18: Spring flow rate – HOF081
SPRING NUMBER : HOF094 weir-gauging
0.12 ) d
n 0.10 seco 0.08 r e 0.06 es p r t i l (
e 0.04 t a
R 0.02 w o l F 0.00 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-19: Spring flow rate – HOF094
SPRING NUMBER : HOF096 weir-gauging
) 0.30 d n 0.25 seco r
e 0.20 es p
r 0.15 t i l ( e t 0.10 weir-gauging
a volumetric R
w 0.05 o l F 0.00 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-20: Spring flow rate – HOF096
PAGE 94 APPENDIX 4: HISTORICAL SPRING FLOW RATES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HOW009 fluorometric
0.4 nd) o c
e 0.3 s
r pe s e
r 0.2 t i l ( e t a
R 0.1 ow l F 0.0 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-21: Spring flow rate – HOW009
SPRING NUMBER : HOW015 fluorometric
0.30
ond) 0.25 c e s
r 0.20 pe s e
r 0.15 t i l ( e
t 0.10 a R 0.05 ow Fl 0.00 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-22: Spring flow rate – HOW015
SPRING NUMBER : HOW025 weir-gauging 0.080
) 0.070 ond
c 0.060 e s
r 0.050 e p
s 0.040 e r t i l
( 0.030
e t
a 0.020 R 0.010 ow
Fl 0.000 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-23: Spring flow rate – HOW025
APPENDIX 4: HISTORICAL SPRING FLOW RATES PAGE 95 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HSS011 weir-gauging 0.5 ) d n 0.4 eco s
r
e 0.3 es p r t i
l 0.2 ( e t a 0.1 R w o l
F 0.0 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-24: Spring flow rate – HSS011
SPRING NUMBER : HSS012 weir-gauging 0.08 0.07 ond)
c 0.06 e s r 0.05 pe
s 0.04 e r t i l 0.03 ( e t
a 0.02 R 0.01 ow
Fl 0.00 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-25: Spring flow rate – HSS012
SPRING NUMBER : HSS024 weir-gauging
0.08 ) 0.07 nd o c
e 0.06 s r 0.05 pe
s
e 0.04 r t i l 0.03 ( e t
a 0.02 R
w 0.01 o
Fl 0.00 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2
Monitoring Period (years)
Figure 17-26: Spring flow rate – HSS024
PAGE 96 APPENDIX 4: HISTORICAL SPRING FLOW RATES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : HWF003 fluorometric
0.12 ) d n 0.10 seco
r 0.08 e es p
r 0.06 t i l (
e
t 0.04 a R
w 0.02 o l F 0.00 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-27: Spring flow rate – HWF003
SPRING NUMBER : HWF048 weir-gauging 2.50
) 2.25
ond 2.00 c
e weir-gauging 1.75 dye-gauging s r 1.50 pe
s 1.25 e r t i
l 1.00 (
e 2nd injection t 0.75 a
R 0.50 w
o 0.25 1st injection Fl 0.00 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-28: Spring flow rate – HWF048
SPRING NUMBER : LES001 weir-gauging 3.0 ) d
n 2.5 seco
r 2.0 e
es p 1.5 r t i l (
e 1.0 t a R 0.5 w o l F 0.0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-29: Spring flow rate – LES001
APPENDIX 4: HISTORICAL SPRING FLOW RATES PAGE 97 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : LFE001 weir-gauging
0.30 d)
on 0.25 c e s
r 0.20 e p
s
e 0.15 r t i l (
e 0.10 t a
R 0.05 ow
Fl 0.00 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2
Monitoring Period (years)
Figure 17-30: Spring flow rate – LFE001
SPRING NUMBER : LFE006 weir-gauging
0.12
0.10 ond) c e s
r 0.08 e p
s 0.06 e r t i l
( 0.04 e t a
R 0.02 ow
Fl 0.00 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-31: Spring flow rate – LFE006
SPRING NUMBER : LGS002 weir-gauging 1.2
1.0 ond) c e s
0.8 r pe
s 0.6 e r t i l
( 0.4 e t a R 0.2 ow
Fl 0.0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-32: Spring flow rate – LGS002
PAGE 98 APPENDIX 4: HISTORICAL SPRING FLOW RATES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : LGS004 weir-gauging 2.5 ) d n 2.0 eco s
r
e 1.5 es p r t i
l 1.0 ( e t a
R 0.5 w o l F 0.0 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 9 9 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 19 19 19 19 19 1 1 1 1 1 1 1 1 1 1 19 1 1 2 2 20 2 2 2 2 20 2 2 2 2
Monitoring Period (years)
Figure 17-33: Spring flow rate – LGS004
SPRING NUMBER : LMS004B weir-gauging
1.6 1.4 ond)
c 1.2 e s r 1.0 pe
s 0.8 e r t i l 0.6 ( e t
a 0.4 R
0.2 ow
Fl 0.0 2 1 8 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 0 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-34: Spring flow rate – LMS004B
SPRING NUMBER : WDS001 weir-gauging
1.2 ) d
n 1.0 co se
r 0.8 e
es p 0.6 r t i l (
e 0.4 t a R 0.2 w o l F 0.0 1 4 0 0 0 0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2 2002 2003 2 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-35: Spring flow rate – WDS001
APPENDIX 4: HISTORICAL SPRING FLOW RATES PAGE 99 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : WDS042 weir-gauging
0.10 )
d 0.09 n
o 0.08 c
se 0.07
r e 0.06 p s
e 0.05 r t i l 0.04 ( e
t 0.03 a
R 0.02 w o
l 0.01 F 0.00 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 8 8 8 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 1 1 9 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 198 198 198 198 1 1 1 198 1 1 1 1 199 1 1 1 1 199 2 2 2 2 2 2 200 200 2 2 2 2
Monitoring Period (years)
Figure 17-36: Spring flow rate – WDS042
SPRING NUMBER : WDS052 weir-gauging
0.012
0.010 ond) c e s
r 0.008 pe s
e 0.006 r t i l (
e 0.004 t a R 0.002 ow Fl 0.000 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-37: Spring flow rate – WDS052
SPRING NUMBER : WWS001 weir-gauging 0.14
d) 0.12 on c
e 0.10 s r e
p 0.08
s e r t
i 0.06 l ( e t 0.04 a R 0.02 ow
Fl 0.00 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 9 9 9 9 9 9 198 198 198 198 198 198 198 198 199 199 199 1 1 199 1 199 199 199 200 200 200 200 200 200 200 200 200 200 201 201
Monitoring Period (years)
Figure 17-38: Spring flow rate – WWS001
PAGE 100 APPENDIX 4: HISTORICAL SPRING FLOW RATES 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
SPRING NUMBER : WWS002 weir-gauging 1.0 ) d
n 0.8 eco s
r
e 0.6 es p r t i
l 0.4 ( e t a
R 0.2 w o l F 0.0 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 000 001 002 003 004 005 006 007 008 009 010 011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2
Monitoring Period (years)
Figure 17-39: Spring flow rate – WWS002
SPRING NUMBER : WWS004 weir-gauging 1.2 ) d
n 1.0 o c e s
0.8 r pe
s 0.6 e r t i l
( 0.4 e t a R 0.2 ow
Fl 0.0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Monitoring Period (years)
Figure 17-40: Spring flow rate – WWS004
SPRING NUMBER : WWS013 weir-gauging
0.05
ond) 0.04 c e s r 0.03 pe
s e r t i l 0.02 ( e t a
R 0.01 ow Fl 0.00 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20
Monitoring Period (years)
Figure 17-41: Spring flow rate – WWS013
APPENDIX 4: HISTORICAL SPRING FLOW RATES PAGE 101
1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
18 APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10
FY10 FY09 Historical range FY10 average average average Site No. EC25 pH EC25 pH 5th 95th Above Comments of (µS/cm) (µS/cm) percentile percentile 95th records percentile Beatrice Bore HBS004 2 2950 8.25 2950 7.90 3255 4220 Boocaltaninna 1 1584 6.64 1629 6.49 1240 1780 Bopeechee HBO004 2 3275 7.60 3525 7.35 3500 4660 Bopeechee HBO007 2 5150 7.95 5150 7.55 3588 5755 Bopeechee HBO011 2 3495 7.88 5065 7.43 3502 5364 Bopeechee Bore HBO013 4 4205 7.29 3973 7.12 3454 4284 Callanna 1 3320 7.71 1629 8.01 2780 3476 Cannuwaukaninna 1 2026 6.79 2031 6.95 1738 2172 Chapalana 1 1884 7.39 1893 7.51 1733 2108 Charles Angus 1 2910 7.41 2875 7.15 2784 3143 Clayton #1 1 1964 7.31 1985 7.42 1768 2283 Clayton #2 1 1910 7.32 1984 7.45 1681 2164 Clayton Dam 2 4560 7.58 2779 6950 No access permitted in FY09 Cooranna 4 2345 8.00 2352 8.03 2184 2618 Cooryaninna 1 1735 7.08 1719 7.20 1501 1906 Coward CBC001 2 7150 7.55 7350 7.35 5790 7800 Coward CBC002 2 3385 7.24 4015 6.76 3168 5530 Coward CBC013 2 5400 7.35 5550 7.00 4711 5795 D2 5 1918 6.76 1934 6.56 1714 2093 D3 5 2019 6.48 2146 7.08 1921 2500 Davenport WDS001 2 3800 7.90 3750 7.70 3014 4180
APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10 PAGE 103 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
FY10 FY09 Historical range FY10 average average average Site No. EC25 pH EC25 pH 5th 95th Above Comments of (µS/cm) (µS/cm) percentile percentile 95th records percentile Davenport WDS042 2 4250 8.60 4100 7.90 3020 4350 Davenport WDS052 2 2750 8.05 3750 7.80 2357 5530 Dead Boy HDB004 2 3800 7.85 4200 7.55 2862 4536 Dead Boy HDB005 2 4450 7.95 6350 8.30 2885 5172 Dulkaninna 1 1411 6.81 1798 7.16 1564 2001 Emerald LES001 2 4200 8.65 4550 8.90 2911 4693 Fred LFE001 2 3000 7.50 3900 9.70 2822 4475 Fred LFE006 2 3150 7.85 2450 8.00 2385 4230 Frome Creek 1 2870 7.86 2660 7.23 2452 2936 GAB1 2 5215 7.58 5273 7.92 4430 5667 GAB2 0 0 Sub-artesian GAB5 2731 3361 Bore damaged GAB5A 1 2990 8.99 2963 8.79 2704 3253 GAB6 2 3775 7.14 3520 6.93 3142 3881 GAB6A 2 3710 7.19 3540 7.01 3160 3770 GAB7 2 3350 7.23 3218 7.06 3025 3606 GAB8 2 3935 8.32 3740 7.97 2864 3881 Yes GAB10 2 3315 8.42 2993 7.25 2586 3300 Yes GAB11 2 3480 7.43 3285 7.04 2931 3640 GAB12 2 3705 7.02 3570 7.02 3384 3862 GAB12A 2 3690 7.15 3498 7.10 3425 3814 GAB13A 0 0 Sub-artesian GAB14 3135 3757 Production bore - Switched off
PAGE 104 APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
FY10 FY09 Historical range FY10 average average average Site No. EC25 pH EC25 pH 5th 95th Above Comments of (µS/cm) (µS/cm) percentile percentile 95th records percentile FY09 & FY10 GAB14A 0 0 Sub-artesian Production Bore - Switched off GAB15 16000 7.42 3885 14533 FY10 GAB15A 3637 16582 Bore damaged GAB16 2 3890 7.26 3623 7.10 3100 3897 GAB16A 2 3725 7.16 3565 7.11 3462 3947 GAB17 0 0 Sub-artesian Production Bore – Switched off GAB18 4155 7.16 3440 4159 FY10 GAB18A 0 0 Sub-artesian GAB19 2 3415 8.76 3060 7.23 2900 3433 GAB21 2 3905 7.27 3590 6.92 3302 4001 GAB22 2 3720 7.66 3510 7.52 3236 3810 GAB23 0 0 Sub-artesian GAB24 2 3745 7.06 3275 6.95 2763 3859 GAB30A 2 3610 7.13 3410 7.09 3031 3696 GAB31A 2 3385 7.11 3325 7.02 3029 3601 GAB33A 1 4080 7.35 3935 7.23 3606 4259 GAB51 4 2748 7.13 2773 7.08 2610 3128 GAB52 4 2665 7.00 2763 6.05 2342 3046 GAB53 4 2650 6.99 2720 6.87 2493 3060 Georgia 4 2312 6.70 2608 6.68 2197 2915 Gosse LGS002 2 2750 7.45 2950 7.00 2677 3202
APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10 PAGE 105 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
FY10 FY09 Historical range FY10 average average average Site No. EC25 pH EC25 pH 5th 95th Above Comments of (µS/cm) (µS/cm) percentile percentile 95th records percentile Gosse LGS004 2 2800 7.60 3100 7.40 2522 3119 Hermit Hill HHS028 2 3215 8.03 4355 7.59 2960 5513 Hermit Hill HHS035 2 3380 8.79 5840 8.70 2906 7215 Hermit Hill HHS101 3480 9050 No flow Hermit Hill HHS125A 2 3100 7.78 3000 7.34 2161 3798 Hermit Hill HHS137 2 3700 8.35 4000 8.45 2691 4906 Hermit Hill HHS170 2 2850 8.35 3300 8.65 2599 3630 HH1 2 3105 7.49 2997 7.31 2806 3328 HH2 2 3515 7.44 3340 7.35 2849 3574 HH3 0 0 Sub-artesian HH4 2 3175 7.54 2987 7.35 2730 3569 Highway 1 3590 7.65 3450 7.42 3110 3780 Jackboot 10 4263 7.20 4362 7.04 4110 4730 Jewellery Creek 1 1674 6.97 1693 7.09 1529 1838 Kopperamanna 1 3950 6.62 1891 6.89 1672 2645 Yes Lake Billy #2 4 5850 7.22 5783 7.30 4860 6000 Lake Harry 1 2285 7.35 2330 7.49 2302 2590 Marion 1 2353 7.31 2310 7.54 2192 2596 Maynards 1 3450 7.58 3310 7.75 3160 3733 MB1 4 2735 7.46 2804 7.29 2319 3041 MB2 0 0 Sub-artesian MB4 3841 4546 Bore failed McLachlan LMS004B 2 2950 8.80 3600 8.35 2646 3649
PAGE 106 APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
FY10 FY09 Historical range FY10 average average average Site No. EC25 pH EC25 pH 5th 95th Above Comments of (µS/cm) (µS/cm) percentile percentile 95th records percentile Morphetts 1 3980 7.68 3815 7.69 3629 4097 Morris Creek 1 3010 7.25 2895 6.98 2829 3195 Muloorina 1 2620 7.06 2600 7.41 2402 2880 New Years Gift 2 5105 7.57 4887 7.63 3761 5060 Yes OB1 4 2527 7.58 2533 7.60 2472 2780 OB3 4 2730 7.49 2703 7.59 2630 3048 OB6 4 2635 7.37 2687 7.43 2507 2954 Old Finniss HOF004 2 4650 9.00 4100 8.25 2276 4652 Old Finniss HOF033 2 4900 7.95 8100 8.90 4200 13050 Old Finniss HOF081 2 3750 8.05 4200 7.75 2998 4942 Old Finniss HOF094 2 3050 8.80 6600 8.60 3137 8160 Old Finniss HOF096 2 3000 7.85 3350 7.80 2950 3500 Old Woman HOW009 2 9800 8.05 9600 7.50 7911 10802 Old Woman HOW015 2 5150 8.25 7300 8.50 3982 8380 Old Woman HOW025 2 3200 7.90 4000 7.70 2701 4881 Peachawarrina 1 2820 6.81 2770 7.08 2508 3000 Peters 4 2125 7.65 2210 7.76 2085 2493 S1 4 2597 7.66 2743 7.66 2562 3029 S2 4 3553 7.95 3468 8.03 3080 3816 S3 0 0 Insufficient flow S3A 4 2295 7.93 2261 7.71 2159 2454 S4 4 2608 7.42 2607 7.59 2377 2840 S5 4 2054 7.41 2743 7.32 2009 2500
APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10 PAGE 107 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
FY10 FY09 Historical range FY10 average average average Site No. EC25 pH EC25 pH 5th 95th Above Comments of (µS/cm) (µS/cm) percentile percentile 95th records percentile Sinclair 1 1938 7.23 1939 7.38 1816 2188 Sulphuric HSS011 2 3850 7.35 3600 7.30 3242 4006 Sulphuric HSS012 2 5100 8.10 6815 9.15 3096 5070 Yes Sulphuric HSS024 2 3350 8.45 3850 8.50 2480 4500 Tarkanina #2 2 1953 7.79 1922 2257 No access permitted in FY09 Tent Hill 0 0 Insufficient flow Two Mile #2 2746 3762 Sub-artesian Venables 4 5763 7.37 5480 7.42 5397 6993 Cannot measure quality due to WCB1 2380 8.15 2618 3083 rocks being ejected from bore WCB2 4 2257 7.70 2132 7.80 2154 2560 Welcome WWS001 2 7300 8.15 6600 7.75 3724 7850 Welcome WWS002 2 7500 8.15 7600 7.80 6155 8105 Welcome WWS004 2 3750 8.20 3250 7.90 3580 4212 Welcome WWS013 2 5550 7.95 6000 7.95 2600 6632 Well Creek #2 4 2524 7.97 2490 8.02 2169 2669 West Finniss HWF002 2 3250 8.20 4350 8.15 3375 5225 West Finniss HWF003 2 2950 8.50 4900 8.50 3144 6340 West Finniss HWF048 2 3450 7.95 4100 8.00 2778 5520 Wirringinna Spring 4 9245 9.51 8575 9.63 4356 9850 MWI001 Yarra Hill 2 1974 7.73 1689 2214 No access permitted in FY09
PAGE 108 APPENDIX 5: SUMMARY OF FIELD CHEMISTRY DATA FY10
BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
19 APPENDIX 6: CONDUCTIVITY TREND DATA
Conductivity trend graphs are provided here for: • Bores and springs that have a regression coefficient that statistically differs from zero, at the 95% confidence level and is greater than 0.10 or less than -0.10. • Bores and springs that have an average conductivity for FY10 that is greater than the 95th percentile for that bore or spring (see Appendix 5) Refer to section 8 for discussion of these data. The following statistics are provided for each graph in this section: n The number of data points used in the regression calculation. F Overall F test value for null hypothesis H0:m=0 versus the alternative Ha:m≠0, where m is the slope of the line (regression coefficient) in the equation y=mx+b. p The associated significance value for the F test at the 95% confidence level. r2 R squared.
8000
) 6000 m c S/
µ 4000 ( 5 2
EC 2000
0 98 99 00 01 02 03 04 05 06 07 08 09 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 30, F = 9.396, p = 0.005, r2 = 0.251 Figure 19-1: Conductivity trend for Bopeechee HBO007
PAGE 110 APPENDIX 6: CONDUCTIVITY TREND DATA 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
8000
) 6000 m c S/
µ 4000 ( 5 2
EC 2000
0 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 18, F = 5.998, p = 0.026, r2 = 0.273 Figure 19-2: Conductivity trend for Clayton Dam
6000 ) 4000 cm / S µ
25 ( 2000 C E
0 86 88 90 92 94 96 98 00 02 04 06 08 10 un- un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J J
• n = 67, F = 5.803, p = 0.019, r2 = 0.082 Figure 19-3: Conductivity trend for GAB8
APPENDIX 6: CONDUCTIVITY TREND DATA PAGE 111 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
4000 ) m c S/
µ 2000 ( 5 2 EC
0 86 88 90 92 94 96 98 00 02 04 06 08 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 69, F = 0.122, p = 0.728, r2 = 0.002 Figure 19-4: Conductivity trend for GAB10
20000
16000 ) cm / 12000 S µ 8000 25 ( C E 4000
0 86 88 90 92 94 96 98 00 02 04 06 08 10 un- un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J J
• n = 79, F = 520.245, p = 5.43x10-36, r2 = 0.871 Figure 19-5: Conductivity trend for GAB15
PAGE 112 APPENDIX 6: CONDUCTIVITY TREND DATA 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
25000
20000 ) m c 15000 S/ µ (
5 10000 2
EC 5000
0 86 88 90 92 94 96 98 00 02 04 06 08 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 79, F = 391.518, p = 7.81x10-31, r2 = 0.845 Figure 19-6: Conductivity trend for GAB15A
4000
) 3000 m c S/
µ 2000 ( 5 2
EC 1000
0 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 15, F = 1.953, p = 0.186, r2 = 0.131 Figure 19-7: Conductivity trend for Kopperamanna
APPENDIX 6: CONDUCTIVITY TREND DATA PAGE 113 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
8000
) 6000 m c S/
µ 4000 ( 5 2
EC 2000
0 84 86 88 90 92 94 96 98 00 02 04 06 08 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 68, F = 193.879, p = 2.57x10-21, r2 = 0.746 Figure 19-8: Conductivity trend for New Years Gift
16000
) 12000 cm / S
µ 8000 25 ( C
E 4000
0 88 90 92 94 96 98 00 02 04 06 08 10 un- un- un- un- un- un- un- un- un- un- un- un- J J J J J J J J J J J J
• n = 26, F = 6.636, p = 0.017, r2 = 0.217 Figure 19-9: Conductivity trend for Old Finniss HOF033
PAGE 114 APPENDIX 6: CONDUCTIVITY TREND DATA 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
10000
8000 ) m c 6000 S/ µ (
5 4000 2
EC 2000
0 84 86 88 90 92 94 96 98 00 02 04 06 08 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 58, F = 13.863, p = 4.58x10-4, r2 = 0.198 Figure 19-10: Conductivity trend for Old Finniss HOF094
10000
8000 ) m c 6000 S/ µ (
5 4000 2
EC 2000
0 86 88 90 92 94 96 98 00 02 04 06 08 10 Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun- Jun-
• n = 72, F = 7.861, p = 0.007, r2 = 0.101 Figure 19-11: Conductivity trend for Old Woman HOW015
APPENDIX 6: CONDUCTIVITY TREND DATA PAGE 115 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
10000
8000
6000
4000
EC25 (µS/cm) EC25 2000
0 Jun-86 Jun-88 Jun-90 Jun-92 Jun-94 Jun-96 Jun-98 Jun-00 Jun-02 Jun-04 Jun-06 Jun-08 Jun-10
2 • n = 77, F = 9.340, p = 0.003, rP P = 0.111 Figure 19-12: Conductivity trend for Sulphuric HSS012
8000
6000
4000
EC25 (µS/cm) 2000
0 Jun-94 Jun-95 Jun-96 Jun-97 Jun-98 Jun-99 Jun-00 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10
2 • n = 50, F = 4.511, p = 0.039, rP P = 0.086 Figure 19-13: Conductivity trend for West Finniss HWF048
PAGE 116 APPENDIX 6: CONDUCTIVITY TREND DATA 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
12000 10000 8000 6000 4000 EC25 (µS/cm) EC25 2000 0 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Dec-05 Dec-06 Dec-07 Dec-08 Dec-09
-4 2 • n = 20, F = 19.039, p = 3.75x10P ,P rP P = 0.514 Figure 19-14: Conductivity trend for Wirringinna MWI001
APPENDIX 6: CONDUCTIVITY TREND DATA PAGE 117 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT 20 APPENDIX 7: TEN YEAR FORWARD SCHEDULE FOR GAB ABSTRACTION
OLYMPIC DAM Year Potable Potable Non- Total Water Source of Source of Water Water potable Requirement Water Water Township Plant & Water ML/day GAB GAB ML/day Mine Plant & Borefield A Borefield B ML/day Mine ML/day ML/day ML/day
2010 2.4 7.3 20.0 29.7 4.5 25.2 2011 3.0 8.3 23.2 34.5 5.0 29.5 2012 3.2 8.5 24.1 35.8 5.0 30.8 2013 3.2 8.7 25.4 37.4 6.0 31.4 2014 3.2 8.7 25.4 37.4 6.0 31.4 2015 3.2 8.7 25.4 37.4 6.0 31.4 2016 3.2 8.7 25.4 37.4 6.0 31.4 2017 3.2 8.7 25.4 37.4 6.0 31.4 2018 3.2 8.7 25.4 37.4 6.0 31.4 2019 3.2 8.7 25.4 37.4 6.0 31.4 2020 3.2 8.7 25.4 37.4 6.0 31.4
Notes: • The schedule does not include water for a potential major expansion which would require approval of the EIS as well as other approvals.
PAGE 118 APPENDIX 7: TEN YEAR FORWARD SCHEDULE FOR GAB ABSTRACTION 1 JULY 2009 - 30 JUNE 2010 BHP BILLITON OLYMPIC DAM GREAT ARTESIAN BASIN WELLFIELDS REPORT
21 APPENDIX 8: NOMENCLATURE AND CODING FOR GAB SPRINGS
21.1 Spring Nomenclature and Coding Spring monitoring and discussion of results refers to springs at a number of levels (Kinhill Stearns, 1984): • Individual springs • Spring groups • Spring complexes Individual springs Each individual outlet or vent where artesian water naturally discharges is considered as a spring. The spring is the basic unit for flow measurement and water chemistry analysis. Spring groups Many springs occur in groups associated with the same fault or fracture system, and are in close proximity. Spring complexes A larger aggregation of springs or spring groups is termed a spring complex, and consists of a series of spring groups in close proximity, of similar type and generally within the same hydrological catchment. Spring complexes in turn fit into the larger spring super groupings for the Great Artesian Basin (GAB) defined by Habermehl (1982). Spring numbering system The spring numbering system in use was devised by Roxby Management Services (RMS) to reflect the three levels of spring occurrences. In this alpha-numeric code, the first letter indicates the spring complex, the next two letters indicate the spring group, and the final three numbers indicate an individual spring within that group.
21.2 Monitored Springs A number of springs are monitored regularly for water flow, either by weir gauging or dye gauging. A summary of the numbering system as it applies to those springs is given in Table 21-1. All springs fall within the Lake Eyre super group as defined by Habermehl (1982).
APPENDIX 8: NOMENCLATURE AND CODING FOR GAB SPRINGS Page 119 BHP BILLITON OLYMPIC DAM 1 JULY 2009 - 30 JUNE 2010 GREAT ARTESIAN BASIN WELLFIELDS REPORT
Table 21-1: Monitored springs in the vicinity of Lake Eyre South
Complex code Group code Spring complex Spring group Spring Comments 1 C BC P P Coward Blanche Cup CBC001 Blanche Cup CBC002 CBC013 The Bubbler H BO Hermit Hill Bopeechee HBO004 HBO007 HBO011 H BS Hermit Hill Beatrice HBS004 H DB Hermit Hill Dead Boy HDB004 HDB005 H HS Hermit Hill Hermit HHS028 HHS035 HHS101 HHS125a HHS137 HHS170 H OF Hermit Hill Old Finniss HOF004 HOF033 HOF081 HOF094 HOF096 H OW Hermit Hill Old Woman HOW009 HOW015 HOW025 H SS Hermit Hill Sulphuric HSS011 HSS012 HSS024 H WF Hermit Hill West Finniss HWF003 HWF048 2 L ES P P Lake Eyre Emerald LES001 Emerald Spring L FE Lake Eyre Fred LFE001 LFE006 L GS Lake Eyre Gosse LGS002 LGS004 L MS Lake Eyre McLachlan LMS004 W WS Wangianna Welcome WWS001 WWS002 WWS004 WWS013 W DS Wangianna Davenport WDS001 3 WDS042 WDSKE1 P P 3 WDS052 WDSKE2 P P Notes: 1 • P SpringsP in the Blanche Cup group have been given the group code BS at various times since the original Kinhill Stearns (1984) report. 2 • P SpringsP in the Emerald group were given the group code EM in the original report. 3 • P SpringsP WDSKE1 and WDSKE2 were not included in the original report. The numbers subsequently assigned did not conform with the adopted spring numbering system, but were corrected in 2005 to WDS042 and WDS052 respectively.
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