Brukunga Mine Site

Brukunga Mine Site Water Monitoring Report – 2010 EPA Licence 10577

Mine Completion Program

Minerals and Energy Resources Division Mining Regulation and Rehabilitation Branch

Department of Primary Industries and Resources (PIRSA)

Final Report

December 2011

BRUKUNGA MINE 2010 WATER QUALITY MONITORING REPORT

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ACKNOWLEDGEMENTS The Brukunga Mine Water Monitoring Report is a combined effort, drafted and edited by the following individuals:

PIRSA: Michael McLeary

PIRSA: Chris Henschke

AWQC: Darren Hicks (Macroinvertebrate section)

Staff and companies that have provided valuable services / and or assistance with the collection, analysis, collation, interpretation and presentation of data include:

Peter Grindley (PIRSA)

Mark Seifert (PIRSA)

Ross Stevens (PIRSA)

Australian Water Quality Centre (AWQC)

Water Data Services (WDS)


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EXECUTIVE SUMMARY

The Brukunga Mine operated between 1955 to 1972, quarrying iron sulphide (pyrite and pyrrhotite) from the site of two steep hills in an open pit. The concentrated ore was converted to sulphuric acid, and subsequently used in the manufacture of superphosphate fertiliser. The pyrite and pyrrhotite minerals that remain on site naturally oxidise in air to form acid and the resultant acid and metalliferous drainage (AMD) dissolves other minerals causing heavy metal contamination of the local watercourse.

The land is freehold title held by the Minister for Mineral Resources Development on behalf of the Crown and has been managed by the Department of Primary Industries and Resources - Minerals and Energy Resources Division since 1998.

The key work undertaken on site is the interception and treatment of acid seepage with lime to prevent acid and metals from entering and polluting the local watercourse. The AMD is neutralised in a plant to remove the soluble heavy metals before the cleaned water is released back to Dawesley Creek. The water monitoring program, undertaken in accordance with conditions of the Environment Protection Authority (EPA) site licence No.10577, provides a measure of the success of the interception and treatment program.

In 2003 a major improvement in water quality in the creek downstream of the mine site was achieved primarily due to the construction of a 1.7 km creek diversion drain. In 2005 upgrading of the lime treatment plant was completed, effectively doubling its capacity to treat AMD from the site. These two initiatives have resulted in a marked improvement in downstream water quality, compared to levels measured prior to 2003.

Key points relevant to 2010 include:

• There is consistency with 2010 results as compared to other years (post diversion) which are markedly improved over pre-diversion values.

• Rainfall measured in 2010 was approximately 17% above the long-term average. This resulted in a marked increase in the volume of water treated during 2010.

• Flushes of low pH and high metals are observed downstream of the mine following the drier summer months, but can also be observed to varying degrees sporadically in the wetter months.

• Water quality downstream of the mine generally improves (relative to analytes measured against ANZECC guidelines) with distance (from the mine) in terms of livestock standards. Exceeded trigger values generally relate to sulphate, aluminium and cadmium.

• Eight events were notified to EPA (largely resulting from overflows during or subsequent to periods of heavy rain)


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Table Of Contents ACKNOWLEDGEMENTS .................................................................................................................. II

EXECUTIVE SUMMARY .................................................................................................................. III

1 LICENCE INFORMATION ...................................................................................................... 1

2 INTRODUCTION .................................................................................................................. 2

2.1 Background .............................................................................................................. 2

2.2 Forward Program ..................................................................................................... 4

2.3 Hydrology .................................................................................................................. 5

3 MONITORING ..................................................................................................................... 8

3.1 Monitoring Objectives ............................................................................................. 8

3.2 Monitoring Plan ........................................................................................................ 8

3.2.1 Flow Monitoring and Composite Sampling ..................................................... 10

3.2.2 Biological Monitoring ...................................................................................... 11

3.2.3 Grab Sampling ............................................................................................... 11

3.3 Reporting Trigger Values and Thresholds .......................................................... 12

3.4 Analytical Methods and Limits of Reporting ....................................................... 12

3.5 Evaluation of Quality Control/Quality Assurance ............................................... 12

4 RESULTS & DISCUSSION .................................................................................................. 14

4.1 Flow Monitoring and Composite Sampling ......................................................... 14

4.1.1 Annual Flow Volumes ..................................................................................... 14

4.1.2 Annual Load ................................................................................................... 15

4.2 Biological Monitoring ............................................................................................ 18

4.3 Grab Sampling ........................................................................................................ 18

4.3.1 Spatial Variations for Key Analytes (Zone of Influence) ................................. 18

4.3.1.1 pH .............................................................................................................. 19

4.3.1.2 TDS ........................................................................................................... 19

4.3.1.3 Sulphate .................................................................................................... 20

4.3.1.4 Aluminium and Manganese ....................................................................... 21

4.3.1.5 Cadmium ................................................................................................... 22

4.3.1.6 Copper, Iron and Zinc ............................................................................... 22

4.3.1.7 Lead, Nickel, Chromium and Arsenic ........................................................ 23

4.3.2 Temporal Variations at Each Site (Monthly Pollutant Concentrations) .......... 23

4.3.2.1 Brukunga US (Peggy Buxton Road) ......................................................... 23

4.3.2.2 Brukunga DS ............................................................................................. 24

4.3.2.3 Melbourne Bridge ...................................................................................... 24

4.3.2.4 Downstream Nairne Junction .................................................................... 25

4.3.2.5 SE Freeway ............................................................................................... 26

4.3.2.6 Mt Barker Creek ........................................................................................ 26

4.3.2.7 Bremer River ............................................................................................. 26


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4.3.2.8 Nairne Creek (Control) .............................................................................. 27

4.4 Additional Monitoring ............................................................................................ 28

4.4.1 Rainfall ............................................................................................................ 28

4.4.2 Water Treatment Plant ................................................................................... 28

4.4.2.1 Water Quality ............................................................................................. 28

4.4.3 Tailings Storage Facility ................................................................................. 30

4.4.4 Plant Efficiency ............................................................................................... 34

5 NOTIFIED EVENTS ............................................................................................................ 36

6 CONCLUSION AND PROPOSED ACTIONS ........................................................................... 37

6.1 Conclusion .............................................................................................................. 37

6.2 Actions from 2010 .................................................................................................. 37

6.3 Proposed Actions for 2011 .................................................................................... 37

7 REFERENCES .................................................................................................................. 39

APPENDIX 1 GRAB SAMPLING .................................................................................................. 41

APPENDIX 2 ADDITIONAL MONITORING ....................................................................................... 49

APPENDIX 3 REPORTING REQUIREMENTS .................................................................................... 51

APPENDIX 4 MACRO-INVERTEBRATE REPORT ............................................................................. 52

1 INTRODUCTION ................................................................................................................ 52

2 METHODS ........................................................................................................................ 52

2.1 Sites ......................................................................................................................... 52

2.2 Macroinvertebrate Sampling and Water Quality Measurements ....................... 53

2.3 Macroinvertebrate Sample Processing ................................................................ 54

3.1 Interpretation of Macroinvertebrate Data ............................................................ 56

3.1.1 Species Richness ........................................................................................... 56

3.1.2 Statistical Analyses ........................................................................................ 56

3.1.3 AusRivAS Models ........................................................................................... 57

3.1.4 Missing Taxa .................................................................................................. 58

4 RESULTS ......................................................................................................................... 59

4.1 Macroinvertebrate Richness ................................................................................. 59

4.1.1 2010 Surveys ................................................................................................. 59

4.1.1.1 March 2010 ............................................................................................... 59

4.1.1.2 June 2010 .................................................................................................. 60

4.1.1.3 September 2010 ........................................................................................ 62

4.1.1.4 December 2010 ......................................................................................... 64

4.1.2 Mean taxon richness 1996-2010 .................................................................... 65

4.2 Temporal Changes at Each Site ........................................................................... 65

4.2.1 Peggy Buxton Road ....................................................................................... 66

4.2.2 Brukunga Mine ............................................................................................... 68

4.2.3 Upstream McIntyre Road ............................................................................... 70

4.2.4 Balyarta .......................................................................................................... 71


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4.2.5 Freeway .......................................................................................................... 73

4.2.6 Nairne Creek .................................................................................................. 74

4.3 Comparison of taxon richness and pH over all sites containing riffle habitat from 2006 to 2010 ............................................................................................................. 75

4.4 AusRivAS Outputs ................................................................................................. 76

4.5 Highly Predicted and Missing Taxa ...................................................................... 77

4.5.1 Riffle Habitats ................................................................................................. 77

4.5.2 Edge Habitats ................................................................................................. 79

4.6 Multivariate Analysis Results ............................................................................... 81

4.6.1 Cluster analysis 2001, 2009 ........................................................................... 81

4.6.2 Ordination 2001 and 2010 .............................................................................. 85

5 DISCUSSION AND CONCLUSIONS ...................................................................................... 87

6 THE FOLLOWING IS A SUMMARY OF KEY FINDINGS FROM 2010: .......................................... 91

7 RECOMMENDATIONS ........................................................................................................ 92

8 REFERENCES .................................................................................................................. 93

APPENDIX 1 ............................................................................................................................... 95

Temporal Changes at Each Site ...................................................................................... 95


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1 LICENCE INFORMATION Authorisation Number: 10577 Name of Licensed Facility: Brukunga Water Treatment Plant and Mine Address of Licensed Facility: Watts Rd Brukunga

Report Name and Year: Brukunga Remediation Program: Water Monitoring Report 2010 Reporting Period: January – December 2010

Report Primary Author: Michael McLeary (Program Manager-Mine Completion) Key Contacts:

Title Name Position Phone

EPA Licence Coordinator

Glenn Sorenson Senior Environmental Advisor (EPA)

08 8204 1024

Site Manager Peter Grindley Mine Site Supervisor (PIRSA)

08 8388 6527

Program Manager

Michael McLeary Program Manager – Mine Completion (PIRSA)

08 8204 1145


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2 INTRODUCTION

2.1 Background

The Brukunga Mine lies adjacent to the township of Brukunga in the Adelaide Hills. The site is located 4 km north of Nairne and 40 km east of Adelaide in the Mount Lofty Ranges of South Australia. The site operated between 1955 and 1972, quarrying iron sulphide (pyrite and pyrrhotite) from the side of two steep hills, in an open pit. The Mine was sited within a thickening of the geological formation hosting the pyrite. This formation continues to the north and south of Brukunga, extending some 40km in total. Mining activities did not remove all pyrite and pyrrhotite from the site.

The Mine supplied feedstock for sulphuric acid manufacture for use by the fertiliser industry in the production of superphosphate fertilisers. The development of the Mine was encouraged and sponsored by the State and Federal Governments to provide employment and ensure self-sufficiency in local agriculture. This was in-keeping with Government policy at the time, for the nation to become self-sufficient, increase the population and develop the country. In fact, the Federal Government paid a bounty for the mining of pyrite for sulphuric acid manufacture, under the Sulphuric Acid Bounty Act 1954 and the Pyrites Bounty Act 1960. In the late 1960s cheaper sources of sulphur became available and the Government withdrew the subsidy for pyrite. The Mine closed when the subsidy ended on 31 May 1972.

The Mine produced 5.5Mt of iron sulphide during its 17 years of operation. Approximately 8Mt of waste rock and 3.5Mt of tailings were produced during the operation of the Mine. Three waste rock dumps and a tailings storage facility (TSF) were constructed on the site. Two of the waste rock dumps (the north and south) remain, however the third (east) was largely removed to the tailings storage facility.

The major environmental concern associated with the Brukunga Mine site is the natural oxidation of iron sulphides in air and water, which results in acid and metalliferous drainage (AMD). AMD is widely recognised in the mining industry as the greatest environmental legacy of mining and minerals processing. ‘AMD is generally characterised as water of low pH containing dissolved metals, as is the case at Brukunga’ (TAG, 2008). The impacts of AMD from the site could be detected while the site was operational, downstream in the Mount Barker Creek, Bremer River and Lake Alexandrina and the water has not been suitable for stock consumption, irrigation, domestic or potable use.

During mining, some of the AMD water was controlled by onsite management including using it in the metallurgical plant. Following closure of the Mine in 1972, two caretakers were employed to collect and pump the AMD to a large evaporation lake on the TSF.


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The State Government accepted responsibility for management and remediation of the site in 1977. In 1980, the Government commissioned the acid neutralisation plant to treat acid water from the lake on the TSF. The Department of Engineering and Water Supply (which then became SA Water) was responsible for management of the plant and site from 1980 to 1997. In 1998 responsibility for the site was transferred to the Mineral Resources Division of the Department of Primary Industries and Resources (PIRSA). Within PIRSA the Mine Completion Program is tasked with management of the Brukunga site. Site based activities are largely focused on operation of the treatment plant and land management activities, such as fencing, pest control, fire management etc.

The Brukunga Mine site is listed as a prescribed activity of environmental significance under Schedule 1 of the Environment Protection Act 1993 (the EP Act).

‘4(1) Brukunga Mine Site – the management of the abandoned Brukunga Mine site and associated acid neutralisation plant situated adjacent to Dawesley Creek in the Mount Lofty Ranges.’

Section 36 of the Act requires that a ‘person must not undertake a prescribed activity of environmental significance except as authorised by an environmental authorisation in the form of a licence’.

The Minister for Mineral Resources Development holds an environmental licence (EPA10577) for the site.

In March 1999 the ministerially appointed Brukunga Mine Site Remediation Board (BMSRB) took on the role of managing stakeholder engagement in developing remediation solutions for the site. The BMSRB comprises representatives from the Dawesley Creek Catchment Landcare Group; District Council of Mount Barker; the community and PIRSA; and provides advice to the Minister, Mineral Resources Development on strategies for environmental improvement.

In June 2001, a 10 year rehabilitation programme comprising three stages was recommended and accepted by State Cabinet. The approved strategy has been progressively implemented, with the present state of progress as follows:

• Stage 1: Diversion of Dawesley Creek to reduce acid loads – completed in June 2003.

• Stage 2: Increase Water Treatment Plant Capacity to upgrade and improve efficiency of acid treatment and reduction of sludge – completed in May 2005.


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• Stage 3: Relocation and Rehabilitation of Waste Rock Dumps designed to reduce a source of acidity and metals – not yet commenced.

Prior to the installation of the diversion in 2003, less than 50% of AMD from the site was captured, however following the installation of the diversion the amount of AMD captured and treated increased to approx 90% of AMD produced by the site (in non flood conditions). Following construction of the diversion channel the second stage was implemented that being to increase the peak capacity of the acid neutralisation plant (to ensure that the majority of AMD emanating from the site is collected and treated prior to being released back into Dawesley Creek); this was completed in 2005. The third stage was to relocate the waste rock dumps back into the mine void area (not undertaken).

2.2 Forward Program

A review of the current mine management and remediation strategy was undertaken in 2007, resulting in the development of the Brukunga Mine ‘Forward Program’. The ‘Forward Program’ was designed to be implemented prior to the commitment of capital funding for Stage 3, to ensure that leading practice options would be considered and implemented thereby maximising benefits to the public and the environment.

The Forward Program comprises four key strategies:

• Reconsideration of the strategic goals for rehabilitation of Brukunga;

• Experimental trials of various treatments on Brukunga waste rock samples;

• Use of international experts as a Technical Advisory Group (TAG) to develop solutions; and

• Continued community engagement.

The Forward Program also comprises six operational Phases.

Phase 1 Remediation Option Development – included the establishment of the TAG. The TAG was tasked with recommending (to Government) the most effective technical remediation option(s) for the Brukunga Mine site, with the goal of developing a final remediation option for the site. A final remediation option (mine completion) would allow the return of the land to a use(s) suitable for release from government ownership, requiring no further intervention by, ongoing responsibility for or cost to government and / or the community (in terms of the impacts of AMD). This phase was completed in November 2008. Also during this phase the second strategy (Experimental trials of various treatments on Brukunga waste rock samples) was designed, implemented and monitored.


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Phase 2 Feasibility/Remediation Option Definition – involved the implementation of various studies to determine the feasibility of the preferred option (from Phase 1). It involved determining its likelihood of success, potential cost and future risk. This phase was completed October 2009

Phase 3 Detailed Planning and Design – will involve further detailed studies. A large component of this Phase will be Stakeholder Engagement, including with the community, Government Agencies and other interest groups. As at May 2011 a decision on whether to proceed to this Phase has yet to be made. This phase of works is anticipated to take 18 – 24 months to complete.

Phase 4 Implementation – Upon a final decision resulting from the conclusion of Phase 3 the fourth Phase may involve actual on-ground works, including extensive earthworks, land-forming and revegetation. The timeframe for this Phase will depend largely on community expectations of works scheduling and the availability of funds to undertake works.

Phase 5 Post-closure Monitoring – A Mining and Rehabilitation Program (MARP) will be developed to provide detail on control measures, development of measurable criteria to demonstrate achievement of the outcomes. A Post-Closure Monitoring Plan will be developed to monitor and demonstrate achievement of the closure outcomes stated in the MARP, as well as expectations of the Environment Protection Authority (EPA). The post-closure monitoring period will be agreed with EPA.

Phase 6 Validation – this Phase relates to the completion of the agreed post-closure monitoring and demonstration that the closure outcomes have been achieved. This will provide validation of the Forward Program, the remediation option and positive environmental outcomes for the South Australian community.

2.3 Hydrology

Dawesley Creek, located in the Lower Murray River catchment, can be described as an intermittent stream with small constant flows from autumn to spring, when rainfall predominantly occurs. Average annual rainfall is 575 mm. Periods of no flow occur mostly during the months of January and February.

Upstream of Brukunga, the Dawesley Creek catchment consists of over 2,000 ha of sparsely vegetated open pasture extending northwards roughly 5.5 km.

The Bird in Hand Wastewater Treatment Plant (WWTP) is located near the top of the catchment and discharges treated effluent to a tributary of Dawesley Creek. Historically, the Bird In Hand WWTP released treated effluent year round; however since 2007 effluent is no longer released during summer.


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Dawesley Creek flows from north to south through the Brukunga Mine site. The original creek alignment was partially covered by the South Waste Rock Dump during mining, causing it to be diverted to the east. Dawesley Creek followed this alignment, flowing immediately adjacent to the North and South Waste Rock Dumps. The Dawesley Creek diversion was commissioned in June 2003, isolating the old creek alignment through the Mine site with 1.7 km of bypass drain and open channel. The design capacity was for an annual average recurrence interval flood, with the un-diverted volume of larger floods passed over a gabion basket spillway into the old creek alignment. Sections of the old creek alignment adjacent to the Mine are used for AMD collection. In the event that the diversion overflows and the natural creek bed floods and overtops the downstream weir untreated AMD escapes the site, however it should be noted that this release would be greatly diluted given peak capacity must be reached within the diversion channel to cause the flooding.

Three small creeks (Days Creek, Shepherd’s North Creek and Shepherd’s South Creek) flow into the Mine site from the west, resulting in their flows becoming contaminated by the Mine. The combined “clean” catchment area for these creeks upstream of the Mine site is 152 ha. These creeks probably account for some 50% of mine site runoff.

The reach of Dawesley Creek that traverses through Brukunga south of the diversion channel is thought to be a losing reach in which a proportion of surface water is lost to groundwater via the fractured rock. The exact area and extent of this is not currently known.

Taylor’s Creek joins Dawesley Creek immediately downstream of the Mine. This stream has a catchment area of approximately 500 ha.

Figure 1 shows the drainage system of the Brukunga Mine and surrounds.


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Figure 1 Dawesley Creek Catchment (SKM 2009)

As a result of mining and disturbance of sulphidic materials on site, the Mine became a source of AMD that impacted a range of environmental values (including aquatic ecosystems, stock watering, irrigation, human consumption) downstream to Lake Alexandrina, some 70 km. Whilst substantial improvements were forthcoming with the implementation of the water treatment plant and construction of the diversion channel the effects of AMD are still readily measurable downstream. Contaminants of concern specifically associated with AMD from Brukunga are sulphate, aluminium, iron, manganese, cadmium, zinc and nickel.


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3 MONITORING

3.1 Monitoring Objectives

The impacts of AMD on downstream water quality triggered the inclusion of the Brukunga Mine site and acid neutralisation plant in the EP Act and the requirement to hold a licence under that Act and undertake an extensive surface water quality monitoring program to assess the impacts of the site. The program has been in place since 1996.

The water quality monitoring program was established to:

• Determine annual and seasonal loads of heavy metals entering the Dawesley Creek from the site, by measuring stream flow and metal concentration upstream and downstream of the Mine (composite sampling);

• Determine the extent of impact of the Mine (i.e. the zone of impact) on Dawesley Creek and the Bremer River by undertaking biological (macroinvertebrate) monitoring on a quarterly basis; and

• Determine the temporal and spatial variations of pH and heavy metals concentrations within the zone of impact by undertaking a monthly sampling program (grab sampling).

3.2 Monitoring Plan

The Monitoring Plan for the Brukunga Remediation Program was developed as part of an Environment Improvement Program established by negotiation between EPA and SA Water (which previously managed the site) in August 1996 and approved by EPA in the same year.

Figure 2 shows the monitoring locations and Table 1 lists the type of monitoring undertaken at the various sites.


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Figure 2 Monitoring Point Locations (PIRSA 2009)


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Table 1 Sampling Type and Location

Monitoring Undertaken

Site Grab Sampling

Composite Sampling

Macroinvertebrate Sampling

Brukunga upstream (Peggy Buxton Road) (ref. 4728)

Brukunga downstream (ref. 3158)

Melbourne Bridge (ref. 1951)

Nairne Creek (control) (ref. 1953

Downstream Nairne Creek Junction (ref. 1822)

South East Freeway (ref. 1952)

Mount Barker Creek (ref. 1807)

Bremer River (ref. 1824)

3.2.1 Flow Monitoring and Composite Sampling

Two hydrometric stations were established directly upstream and downstream of Brukunga by the Department of Engineering and Water Supply (E&WS) in 1993. They form part of a system of semi-automatic logging stations that record creek flows in the Adelaide Hills. The volume of flow in the Dawesley Creek is determined as it passes over concrete v-notch weirs.

In 2009 new loggers were installed to minimise data loss from logger failures and in 2010 further work was undertaken to provide real-time telemetry data and to improve the upstream flow rating by installing a Starflow ADCP flow meter in the diversion pipe immediately downstream of the debris trap.

Automatic water sampling facilities were installed at the Brukunga stations in 1998 and chemical analysis commenced on 3 February 1998. These facilities are presently maintained by Water Data Services Pty Ltd (WDS). WDS also collect the fortnightly composite samples and send these to AWQC for analysis.

The water monitoring program requires analysis of the composite water sample be undertaken for the following parameters:

Iron TDS Sulphate


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Manganese Aluminium Chromium

Nickel Cadmium Zinc

Copper Lead

All metals are measured as total metals (as opposed to soluble), in addition to pH and EC (µS/cm) also being recorded. Composite sampling and analysis allows for the conversion of a measured concentration of an analyte into a load of the contaminant for a given period of time, using the corresponding flow data.

Flow and assay data is supplied to the Department of Water by WDS, for storage in the Department’s water data archive.

3.2.2 Biological Monitoring

Biological monitoring, involving the collection and identification of macroinvertebrate species, is conducted quarterly (March, June, September, December) by biologists from the Australian Water Quality Centre (AWQC).

Biological monitoring commenced at six monitoring sites in the Dawesley – Bremer River system in September 1996. Monitoring of riffle sites was introduced in 2006 at the recommendation of AWQC. Sampling and analysis is undertaken in accordance with the Australian Rivers Assessment System (AusRivAS) guidelines.

3.2.3 Grab Sampling

Monthly grab sampling is undertaken at eight sites (refer to Figure 2) by either PIRSA or AWQC (during macroinvertebrate monitoring periods) staff. Unfiltered samples are analysed by AWQC.

The agreed suite of analytes is the same as for the composite samples, with the addition of analysis for acidity as calcium carbonate (to pH 9.5) for four locations, which was initiated in August 2003. The purpose of which was to provide additional information on these sites. On an adhoc basis the analytical suite is extended to cover other metals and parameters.


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3.3 Reporting Trigger Values and Thresholds

PIRSA is required to report against threshold values for livestock, irrigation and aquatic ecosystems within the ANZECC/ARMCANZ (2000) Australian Guidelines for Water Quality Monitoring and Reporting. When reporting results against the guidelines a 90% level of protection suitable for supporting aquatic ecosystems is used, this recognises that the upstream component of the catchment is moderately disturbed. Aquatic results are also adjusted for water hardness as per the guidelines.

3.4 Analytical Methods and Limits of Reporting

Table 2 sets out the analytical methods and level of reporting (LOR) for the various analytes. It should be noted that dependent on the actual equipment used (by AWQC) there may be some degree of variability with respect to LOR. These are applicable to both composite and grab samples.

Table 2 Analytical Methods and Limits of Reporting

Analyte Analytical Method Limit of Reporting

Aluminium Elemental Analysis – ICP Mass Spectrometry 0.001 mg/L Arsenic Elemental Analysis – ICP Mass Spectrometry 0.0003 mg/L Cadmium Elemental Analysis – ICP Mass Spectrometry 0.0001 mg/L Chromium Elemental Analysis – ICP Mass Spectrometry 0.0001 mg/L Copper Determination of Metals – ICP Spectrometry by ICP2 0.005 mg/L Iron Determination of Metals – ICP Spectrometry by ICP2 0.005 mg/L Lead Elemental Analysis – ICP Mass Spectrometry 0.0001 mg/L Manganese Determination of Metals – ICP Spectrometry by ICP2 0.001 mg/L Nickel Elemental Analysis – ICP Mass Spectrometry 0.0001 mg/L Sulphur Determination of Metals – ICP Spectrometry by ICP2 1.5 mg/L Zinc Elemental Analysis – ICP Mass Spectrometry 0.0003 mg/L

3.5 Evaluation of Quality Control/Quality Assurance

During 2010, all monitoring was carried out in accordance with EPA licence 10577 and the associated Water Quality Monitoring Plan.

The analysis of grab, composite and macroinvertebrate samples was undertaken by the Australian Water Quality Centre (AWQC), with NATA corporate accreditation number 1115 for chemical and biological testing. Australian Laboratory Services (ALS) was used for analysis of duplicates.

Flow monitoring, data logging and continuous water sample collection was undertaken by Water Data Services Pty Ltd (WDS), with NATA certification number 7642-2.


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Standard sampling protocols (at Brukunga) for grab samples include the collection of one blind sample per monthly collection round. Inter laboratory duplicates are also undertaken approximately twice per year. Duplicate sampling of composite samples for 2010 was undertaken once for the year.

The data was found to be complete for the monitoring period, with the analytical results supplied by the laboratory satisfying the quality control requirements specified by the EPA.


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4 RESULTS & DISCUSSION

4.1 Flow Monitoring and Composite Sampling

4.1.1 Annual Flow Volumes

Monthly recorded flow volumes measured at the upstream (U/S) and downstream (D/S) monitoring locations are presented in Table 3.

Table 3 Monthly Recorded Flow Volumes (2010)

Total flow U/S (ML) Peggy Buxton Rd

Total flow D/S (ML) ~50m South of Mine

Difference (ML) Mine Site & Surrounds

Jan 0 0 0 Feb 0 0 0 Mar 0 0.0742 0.0742 Apr 0 0.2872 0.2872 May 5.51 15.86 10.35 Jun 12.12 23.19 11.07 Jul 17.68 31.86 14.18 Aug 244.10 387.3 143.2 Sep 694.30 978.7 284.4 Oct 24.52 47.24 22.72 Nov 24.83 29.42 4.59 Dec 26.03 46.43 20.4

Total 1049.09 1560.36 511.27

Annual total flows for both sites are presented in Figure 3. It should be noted that the Bird in Hand Wastewater Treatment Plant (WWTP), located upstream of Brukunga, previously released treated effluent to the Dawesley Creek on a year-round basis. Since the summer of 2007, SA Water no longer release treated effluent to the Creek during the summer months, when there is a demand for the effluent for irrigation. This has resulted in a marked difference in the flow regime experienced by the Dawesley Creek particularly during the drier months.


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Figure 3 Total Annual Flow Volumes Upstream and Downstream of Brukunga Mine

In 2010 a total discharge of 1049ML was observed at the Peggy Buxton Station. During 2010 89% of the total flow occurred in the months of August and September. At the Dawesley Creek DS Brukunga Mine site a total discharge of 1560ML was captured for the year of 2010. This site also captured 88% of the total flow in the months of August and September.

The total flow for the year 2010 at the downstream station was 32.8% more than the upstream station. Water Data Services reported that “The percentage gain between the two sites varies from year to year depending upon the amount of rainfall, rainfall intensity and the state of the catchment. However, it is considered that the 20% increase provides a good average estimate [within a confidence interval] between -8% and + 10% of the true increase (say ± 10%)”.

4.1.2 Annual Load

Tables 4 and 5 detail concentrations of contaminants measured at the upstream and downstream sites during 2010. Measured values are compared with the trigger values for the various analytes listed in the ANZECC guidelines.

0

500

1000

1500

2000

2500

ML

US

DS


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Table 4 Contaminant Concentrations Measured at Upstream Hydrometric Station (Peggy Buxton Rd) in 2010

Table 5 Contaminant Concentrations Measured at Downstream Hydrometric Station in 2010


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The results show that for metal levels measured upstream of the Mine site ANZECC (2000) guideline trigger values for aquatic ecosystems were consistently exceeded for aluminium. Exceedences of irrigation trigger values for iron were also observed upstream. Water quality measured downstream of the Mine site exceeded aquatic trigger values for pH, aluminium, cadmium, copper, manganese, nickel and zinc for the majority of the time. With respect to irrigation guideline triggers, these were exceeded for pH, aluminium, cadmium, iron, manganese and zinc. Trigger values for livestock are noted for TDS, sulphate, aluminium and cadmium. Spikes in contaminant levels can generally be observed following extended periods of no or low flow.

The results indicate that Dawesley Creek water prior to any influence of the Mine exceeds some of the trigger values in order to achieve a 90% level of protection suitable for supporting aquatic ecosystems under the ANZECC (2000) guidelines. The results also indicate that Dawesley Creek water measured downstream of the Mine site consistently exceeds (on a number of analytes) trigger values suitable for supporting aquatic ecosystems. The same results also indicate potentially unsuitable levels of some analytes for the purposes of irrigation use all of the time and stock drinking most of the time.

It should be noted that, while water in Dawesley Creek appears to be suitable for livestock use downstream of the Mine site some of the time, analytes measured by PIRSA only relate to contaminants potentially contributed by the Mine.

Flow volumes and measured concentrations of contaminants were used to calculate the total pollutant load passing each hydrometric station. These annual contaminant loads are detailed in Table 6.

Table 6 Total Annual Contaminant Loads for 2010

Load (2010)

TDS (t)

S (t)

Al (t)

Cd (kg)

Cr (kg)

Cu (kg)

Fe (t)

Pb (kg)

Mn (kg)

Ni (kg)

Zn (kg)

U/S Station 895.7 52.7 3.1 0.1 4.7 6.0 3.3 1.7 85.8 4.3 32.5

D/S Station 2567.3 734.0 43.2 8.6 5.9 497.0 19.0 2.7 3655.5 80.6 2400.6

Average Annual

Contribution

1671.6 681.3 40.1 8.5 1.2 491.0 15.7 1.0 3569.6 76.4 2368.0

% Average Annual

Contribution

65.1% 92.8% 92.8% 98.6% 20.0% 98.8% 82.9% 37.5% 97.7% 94.7% 98.6%

Change from 2009

1258.6 260.3 30.8 -0.4 1.0 476.6 14.3 -2.4 2130.1 24.7 1213.4


18

While the treatment plant is effective in removing a large proportion of the contaminants, the Mine site still continues to contribute a significant contaminant load (particularly as a percentage of contaminants) to the Dawesley Creek catchment, predominantly sulphate, aluminium, cadmium, copper, iron, lead, manganese, nickel and zinc.

Composite sampling over the entire monitoring program has presented a trend where the first flush of the season causes a slug of water with high levels of sulphates and metals and low pH to be measured at the downstream location. This is likely a result of the concentration of sulphates and metals in residual surface and near surface (alluvial and colluvial) waters during the summer months, when there are no flows or reduced flows in Dawesley Creek.

The installation of the Dawesley Creek diversion drain caused a significant and immediate reduction in the load of contaminants contributed by the Mine to Dawesley Creek. However it is considered unlikely that continuing operations as they currently are will have any further marked reduction on the concentration or load of contaminants released to the Creek.

4.2 Biological Monitoring

The Biological monitoring report is presented in Appendix 4.

4.3 Grab Sampling

As discussed previously, monthly grab samples are taken at a total of eight sites (upstream and downstream of the mine). Each individual data point was assessed with respect to the ANZECC water quality guidelines for each of the sampling sites.

This sampling is undertaken to gain an understanding of the spatial and temporal variation of water quality along the length of the creek system and to ultimately determine the ‘zone of influence’ downstream of the mine.

4.3.1 Spatial Variations for Key Analytes (Zone of Influence)

The zone of influence is essentially the portion of the creek system which is affected by the Brukunga mine.

Each individual analyte and water quality attribute has a unique zone of influence depending on many variables such as quality and quantity of downstream inflows, molecular weight of contaminant, detection limit of contaminant etc. It is possible however, to use key analytes as indicators of the overall zone of influence of the Brukunga mine site.


19

4.3.1.1 pH

A key indicator of the ability of water to dissolve and transport heavy metals is pH. Monthly pH readings for most sites in 2010 ranged from 6.8 to 8.1. However, much lower readings occurred at both Brukunga Downstream and Melbourne Bridge in August, September and December, when values dropped to as low as 4.1. This could indicate the impact of overbank flooding around Brukunga mine.

Figure 4 shows the zone of influence for pH within Dawesley Creek catchment. It demonstrates the impact of the installation of the diversion drain on pH levels measured along the Creek.

Figure 4 Zone of Influence - pH

The graph indicates that the zone of impact (i.e. the downstream extent of impacts) of pH has not changed greatly with time and the installation of the diversion. Impacts on pH can still be measured as far downstream as the SE Freeway. The magnitude / scale of the impact has, however, decreased following the installation of the diversion. pHs range from 6 – 7.5 at monitoring locations downstream of the Mine to the SE Freeway, compared with measured ranges of 3.5 – 5.5 over the same distance prior to the installation of the Dawesley Creek diversion, (but inclusive of the water treatment plant).

4.3.1.2 TDS

The monthly Total Dissolved Solids (TDS) did not exceed trigger values at any site in 2010. TDS values commence at around 1000 mg/L in late autumn / early winter falling to around 500 mg/L in late winter / early spring and rising to

3

4

5

6

7

8

9

pH

Location

Pre-diversion

Post diversion

2010


20

around 1500 mg/L in late spring and early summer. Values are a little higher at the Brukunga Downstream (DS) site.

4.3.1.3 Sulphate

Figure 5 shows the average, maximum and minimum sulphate concentration in mg/L for each of the grab sampling sites along the river system in 2010. The graph shows that the sulphate concentration reduces with distance downstream of the mine. The impacts of sulphate can still be measured as far downstream as the SE Freeway.

Figure 5 Zone of Influence – sulphate concentration versus site

Figure 6 shows monthly variability in sulphate at each of the sites. Monthly sulphate readings in 2010 only exceeded trigger values at the Brukunga DS site. There were significant spikes (exceeding the livestock threshold) in June (1150 mg/L representing the early first flush of contaminants) and December (1630 mg/L). At Melbourne Bridge the maximum reading in December (720 mg/L) was less than half that of Brukunga DS and the early first flush was also a lot lower (580 mg/L in June). Further downstream, values continue to decrease to levels of less than 300 mg/L at Bremer River.

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

Max

Average

Min

C o n c e n t r a t i o n


21

Figure 6 Monthly variations in sulphate for each grab sample site

4.3.1.4 Aluminium and Manganese

Two other key contaminants are Aluminium and Manganese.

Aluminium levels exceeded trigger values at all sites for most of the time in 2010. At Brukunga Downstream a reading of 67.2 mg/L in August was the highest since 2004. Some relatively high values (>1 mg/L) occurred at Brukunga Upstream and Nairne Creek (Control) in August and September 2010. The highest individual site readings on record occurred in September 2010 at SE Freeway (5.6 mg/L), Mt Barker Creek (4.1 mg/L) and Bremer River (3.4 mg/L).

Elevated readings occurring well downstream of the mine may be caused by the disturbance of sediments by floodwaters resulting in remobilisation of stored contaminants. There is a particular anomaly in aluminium levels that is not seen for the other metals. One explanation is that aluminium has previously precipitated out along this section of the river system and the large flows in 2010 have now remobilised this particular metal.

0

200

400

600

800

1000

1200

1400

1600

1800 Co

ncen

trat

ion

mg/

L

2010 Water Quality - Sulphate

Upstream (Peggy Buxton Rd)

Downstream Mine

Dawesley Ck (Melbourne Bridge)

Dawesley Ck (Downstream Nairne)

Dawesley Ck (Freeway)

Mt Barker Ck

Bremer River

Nairne Ck (Control)

Livestock Threshold


22

Manganese levels exceeded trigger values for all or most months in 2010 at Brukunga Downstream, Melbourne Bridge, Downstream Nairne Creek Junction and SE Freeway. At other sites trigger values were only exceeded in November or December. The highest readings were 9.7 mg/L at Brukunga DS in December 2010 and 5.2 mg/L at Melbourne Bridge in August 2010. Progressive reductions in maximum readings occur at sites further downstream with a maximum value of only 0.3 mg/L at Bremer River.

4.3.1.5 Cadmium

In 2010, irrigation trigger values were exceeded at Brukunga Downstream and Melbourne Bridge, while aquatic ecosystem trigger values were exceeded at Downstream Nairne Creek Junction and SE Freeway. The highest reading was 0.0319 mg/L at the Brukunga Downstream site in August 2010, while at SE Freeway the highest reading was 0.0027 mg/L.

Figure 7 displays the zone of influence of cadmium within the Dawesley Creek catchment. Cadmium is similar to pH and other metals in that the zone of impact (i.e. the downstream extent of impacts) of cadmium has not changed with time and the installation of the diversion. Impacts on cadmium concentration can still be measured as far downstream as the SE Freeway. The magnitude / scale of the impact has, however, decreased following the installation of the diversion.

Figure 7 Zone of Influence - Cadmium

4.3.1.6 Copper, Iron and Zinc

Copper levels exceeded trigger values (only for aquatic ecosystems) on at least one occasion at a number of sites in 2010 except for Brukunga Upstream, Mt Barker Creek and Nairne Creek (Control). The highest reading was 0.0633 mg/L at Brukunga Downstream in August 2010.

0.0000 0.0050 0.0100 0.0150 0.0200 0.0250 0.0300 0.0350 0.0400 0.0450 0.0500

Cadm

ium

(mg/

l)

Location

Pre-diversion

Post diversion

2010


23

Iron levels exceed trigger values (only for irrigation and not aquatic ecosystems) at all sites for all readings in 2010. The highest reading (30.49 mg/L in August) occurred immediately below the mine. At all other sites the highest reading also occurred in August and were in the 2.5 – 3.0 mg/L range except for Melbourne Bridge which recorded a value of 5.19 mg/L.

Elevated concentrations for iron may be related to turbidity issues and hence tend to feature naturally in surface waters.

Zinc levels exceeded trigger values for all or most months in 2010 at Brukunga Downstream, Melbourne Bridge, Downstream Nairne Creek Junction and SE Freeway. At other sites trigger values were generally not exceeded during 2010. The highest reading was 2.6 mg/L at Brukunga Downstream in August 2010 and this exceeded the irrigation trigger value which had not occurred at this site since June 2004.

4.3.1.7 Lead, Nickel, Chromium and Arsenic

Lead, nickel, chromium and arsenic readings have not exceeded trigger values at any site during 2010 and there is no significant difference between sampling sites. Nickel readings at Brukunga Downstream and Melbourne Bridge (e.g. 0.02 mg/L) are an order of magnitude higher than the other sites.

In summary, the zone of impact of pH, sulphate, manganese and cadmium is the SE Freeway (some 13 km downstream of the mine). However aluminium and iron had elevated values across all of the monitored sites in the Dawesley Creek catchment in 2010 probably due to floodwaters stirring up sediments resulting in remobilization of stored metals.

4.3.2 Temporal Variations at Each Site (Monthly Pollutant Concentrations)

At each of the eight grab sample sites, annual averages are presented for pH and total analyte concentrations (mg/L). While averages can be misleading in small and highly variable datasets, they can be indicative of general trends over time. Not all of the analytes are listed in the tables, but only those that exceed trigger values most of the time (i.e. aluminium, iron, manganese and zinc).

4.3.2.1 Brukunga US (Peggy Buxton Road)

Year pH Aluminium Iron Manganese Zinc

2002 2004 2006 2008 2010

7.6 7.7 7.7 7.6 7.3

0.9 0.6 0.5 0.3 0.6

2.1 1.0 1.2 1.1 1.7

<0.1 0.1 0.1

<0.1 0.1

negligible


24

2010(composite) 7.6 0.8 1.6 <0.1

The 2010 grab sample datasets indicate that the average pH at this site has been remained relatively constant since 2002, with a slight fall in 2010. Concentrations of analytes have remained relatively constant since records commenced in 2002. An anomalous reading for manganese occurred in December 2010 (0.3 mg/L) and this was the highest reading on record at this site.

Comparison of average yearly grab sample data with average yearly composite data indicates pH and aluminium readings are a little higher in the composite data. TDS and sulphate levels are also elevated in the composite dataset.

4.3.2.2 Brukunga DS


2002 2004 2006 2008 2010

2010(composite)

5.5 6.1 7.2 7.0 6.2 5.8

57 12 6 3 12 19

8.7 1.9 4.9 1.8 6.3 5.6

6.4 2.0 2.4 0.7 2.2 2.3

3.8 1.1 0.5 0.2 0.6 2.4

In 2010 the average pH at this site has fallen back to 2004 levels. Low pH readings occurred in August (4.1) and December (4.7) and these were the lowest since June 2004 (4.0). The lowest pH recorded was 3.2 in March 2002.

Concentrations of a number of analytes showed significant increases in 2010. Aluminium and iron concentrations were the highest since pre-diversion levels. Cadmium also showed increased concentrations with the reading of 0.0319 in August 2010 being the highest since January 2002 (0.036). Similarly, August results for copper, iron and manganese were as high as or higher than 2002 readings for these metals.

Comparison of average yearly grab sample data with average yearly composite data indicates lower pH and iron readings but elevated aluminium and zinc levels in the composite data. TDS and sulphate levels are also elevated in the composite dataset.

4.3.2.3 Melbourne Bridge


2002 2004

3.8 6.2

44 0.7

1.9 1.8

6.6 1.8

4.1 0.3


25

2006 2008 2010

7.3 6.9 6.3

0.7 0.5 2.8

1.5 0.8 2.3

1.1 1.0 1.0

0.1 0.3 0.6

The annual average pH at this site has increased significantly from pre-diversion levels in 2002. However, there was a reduction in average pH in 2010. The lowest pH occurred in August (4.4) which was the lowest since February 2004 (4.2). The lowest pH recorded was 3.5 in 2002.

Average concentrations of analytes as indicated in the table showed increases in 2010 (apart from manganese) with iron being the highest on record. Significantly higher concentrations of aluminium occurred in August (9.7) and September 2010 (14.7). These were the highest readings since pre-diversion levels in 2002.

Cadmium levels again reached trigger values in 2010 with July and August results on par with 2002 levels. The average iron levels were the highest on record in 2010, even exceeding pre-diversion levels. Average annual manganese levels have remained relatively constant since 2004 while zinc levels were the highest since 2002.

4.3.2.4 Downstream Nairne Junction


2002 2004 2006 2008 2010

6.2 6.7 7.1 7.2 7.3

3.1 0.9 0.5 0.1 1.0

0.4 0.6 0.4 0.5 0.9

2.6 1.0 0.7 0.4 0.9

1.0 0.6 0.3 0.2 0.4

The average annual pH at this site has been steadily increasing since 2002. Average concentrations of analytes as indicated in the table showed slight increases in 2010 with iron being the highest on record. A relatively high aluminium level occurred in September 2010 (5.2), this being the highest monthly reading since August 2002.

Cadmium levels exceeded trigger values on a number of occasions in 2010 and were the highest since 2006. The average iron levels were the highest on record in 2010, even exceeding pre-diversion levels. Average annual manganese levels were the highest since 2004 with the highest monthly reading of 3.14 mg/L in December being the highest reading since 2002. Similarly, the highest monthly reading for zinc occurred in December and was the highest reading since July 2004.


26

4.3.2.5 SE Freeway


2002 2004 2006 2008 2010

5.1 6.5 6.9 7.1 7.2

2.3 0.2 0.1 0.2 1.2

1.4 0.3 0.1 0.3 1.1

3.5 1.2 0.5 0.2 0.6

1.4 0.6 0.2 0.2 0.2

The average pH at this site has been steadily increasing since 2002. Average yearly concentrations of analytes, (apart from zinc) showed increases in 2010.

4.3.2.6 Mt Barker Creek


2002 2004 2006 2008 2010

7.9 7.9 7.8 7.6 7.5

0.4 0.2 0.1 0.3 1.1

0.4 0.4 0.2 0.5 1.2

0.2 0.2 0.3 0.2 0.2

0.04 0.02 0.04 0.04 0.06

The average annual pH has decreased slightly since 2002. Average aluminium and iron concentrations both increased significantly at this site in 2010. For example, an aluminium level of 4.16 mg/L was recorded in September 2010 with the previous highest being 2.03 mg/L in 2002. This may be related to the remobilisation of stored contaminants from creek bed sediments in 2010.

Average zinc levels also increased to a new high in 2010. A record zinc reading (0.216 mg/L) occurred in December 2010 exceeding the previous high of 0.166 mg/L in 2002.

4.3.2.7 Bremer River


2002 2004 2006 2008 2010

7.9 7.8 7.9 7.5 7.5

0.3 0.4 0.5 0.4 1.2

0.3 0.4 0.5 0.5 1.2

0.3 0.2 0.2

0.09 0.1

0.02 0.05 0.02 0.03 0.03


27

The annual average pH at this site has decreased slightly since 2002. Average aluminium and iron concentrations both increased significantly at this site in 2010. Again this is possibly due to remobilisation of stored metals in sediments due to strong river flows.

4.3.2.8 Nairne Creek (Control)


2002 2004 2006 2008 2010

7.7 7.9 7.6 7.6 7.6

0.2 0.5

<0.1 0.1 0.9

0.2 0.8 0.2 0.3 1.0

negligible negligible

The average pH at this site has been remained relatively constant since 2002. Average concentrations of aluminium and iron have increased in 2010 to record highs with the highest reading on record for aluminium in September 2010 (3.8 mg/L) and the highest reading on record for iron in September 2010 (2.4 mg/L). Elevated concentrations for both iron and aluminium can be related to turbidity issues and so may not be a direct consequence of AMD. Trigger values were not exceeded for any other analytes in 2010 at this site.

In summary, flushes of low pH and high metals are observed downstream of the mine following the drier summer months, but can also be observed to varying degrees sporadically in the wetter months. In 2010, this was particularly evident in spring and early summer due to large rainfall events resulting in flooding along the river system.

Anomalous readings for aluminium and iron occurred outside of the zone of impact of the mine during 2010. Creek sediments can potentially store high metal loads derived from past pollutant discharges with metals precipitating out at various locations downstream. Remobilisation of these stored metals can then occur during flood events.

As with results obtained from composite sampling, the installation of the Dawesley Creek diversion drain has caused a significant and immediate reduction in the concentration of contaminants measured as part of the grab sampling program.

Further details of grab sampling results are available in Appendix 1.


28

4.4 Additional Monitoring

4.4.1 Rainfall

Average annual rainfall recorded since 1975 at Brukunga Mine is 572 mm, most of which falls between May and October, inclusive. Figure 8 compares the monthly rainfall for 2010 with the average long term rainfall for the site.

Figure 8 Monthly Rainfalls

Annual rainfall has a significant impact on the volume of AMD produced at the Mine site. This subsequently impacts plant operations with increased use of reagent and resultant sludge production. The timing of rainfall events determines the concentration of contaminants reporting to the treatment plant, with a first flush of highly concentrated salts, acid and metals after dry periods normally occurring each year.

Brukunga experienced 668.7mm of rain in 2010 which was the sixth highest recorded annual rainfall since recording commenced at site in 1975.

4.4.2 Water Treatment Plant

4.4.2.1 Water Quality

The environmental approval and associated water quality monitoring program focuses on the water quality upstream and downstream of the Mine site, however this does not include the quality of AMD contaminated water treated at the acid neutralisation plant, or the quality of treated water produced by the plant.

0

20

40

60

80

100

120

140

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tota

l Mon

thly

Rai

nfal

l (m

m)

Month

Brukunga Monthly Rainfall for 2010

2010 Monthly Rainfall

Average Monthly Rainfall 1975-2010


29

Appendix 2 provides tables detailing water quality measured at the seepage collection ponds (pre – treatment) and at the second clarifying pond (post treatment). Please note that monitoring of the clarifying pond only commenced in 2009.

When considering pH and sulphate levels there are marked differences between pre and post treated water as observed in Figure 9. Of note is that for both pH and sulphate ANZECC 2000 livestock trigger values are exceeded both pre and post treatment. Aluminium and cadmium results are also presented in Figure 10, aluminium still remains unsuitable when measured against livestock values, but cadmium is reduced often below detection limit.

Figure 9 Pre & Post Treatment pH

0

1

2

3

4

5

6

7

8

9

10

pH

post-treatment

pre-treatment

ANZECC Guideline - Suitable for Irrigation


30

Figure 10 Pre & Post Treatment Cadmium and Aluminium Values

4.4.3 Tailings Storage Facility

Concentration of ore following mining produced 3.5 Mt of waste in the form of finely ground sand tailings, which were deposited in a shallow farm valley. The tailings storage facility (TSF) has been progressively capped and revegetated since 1980. The vegetated cover provides erosion protection and reduces infiltration of rainfall. It also provides habitat for wildlife, however a recent preliminary survey suggests that this vegetation will not be sustainable in the long term, with evidence that the vegetation is significantly poorer than similar species within the Mine site.

Deep drainage through the TSF is monitored via:

• A network of 19 pore water monitoring bores, which have been monitored monthly since 2000, to assess the trend in pore water levels within the TSF;

• A v-notch weir, which measures the flow of seepage from the toe of the wall of the TSF.

Figure 11 demonstrates that, since the capping and revegetation of the TSF, there has been a steady decline in groundwater levels within the TSF. Bore

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Sulp

hate

mg/

l

post-treatment

ANZECC Guideline - Threshold for Agricultural use


31

KAN040 is located within the front, centre (western) portion of the TSF and therefore provides a good indication of groundwater level trends within the TSF. This bore has demonstrated an average annual drop in standing water level of 0.14 m/yr.

Figure 11 Average Depth to Water Table in the TSF (KAN040)

The volume of seepage reporting to the seepage ponds has reduced over time, as demonstrated by Figure 12. This indicates that the vegetation cover has been successful, at least in part, in minimising the infiltration of rainfall into the TSF. Anecdotal evidence indicates that there is a small fresh water spring located within the TSF; therefore it would be impossible for the pore water to drain down completely. It is possible, however that the rate of seepage from the toe of the TSF is approaching steady state. The same graph also shows some relationship to corresponding rainfalls particularly since 2006.

17000

17500

18000

18500

19000

19500

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Dep

th to

wat

er (m

m)

Average Depth to Water in Tailings Storage Facility

Annual Average


32

Figure 12 Annual Seepage from TSF vs. Rainfall

There has been no significant change in the concentration of contaminants reporting to the seepage ponds (and then the treatment plant) from the TSF over time, as shown in Table 7.

0

100

200

300

400

500

600

700

800

20000

21000

22000

23000

24000

25000

26000

27000

28000

29000

2002 2003 2004 2005 2006 2007 2008 2009 2010

Rai

nfal

l (m

m)

Vol

ume

(kL)

Average Annual Seepage kL

Rainfall (mm)


33

Table 7 Quality of Seepage from the Tailings Storage Facility


34

4.4.4 Plant Efficiency

Since May 2007, monthly grab samples have been taken of water from the acid seepage ponds at the base of the TSF (plant feed) and from January 2009 the clarifying ponds (treated water prior to release into diversion). Prior to that, quarterly samples were taken from the seepage ponds.

Figure 13 displays the volume of contaminated water treated daily during 2009.

-

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

Volu

me

(kL)

Month

Seepage Volume Treated in 2010

Volume (kL)

Figure 13 Volume of Water Treated

The acid treatment plant is designed to manage the largest possible volume of contaminated water; therefore it operates at partial capacity for much of the year. Plant utilisation is highest during the winter months, this correlates with high rainfall and increased seepage and contaminated run-off during these periods. During these periods of high demand the plant operates at 100 % capacity, running 24 hours per day, 7 days per week. Table 8 details the monthly percentage utilisation of the plant, i.e. the percentage of the total capacity of plant operation.


35

Table 8 Monthly Percentage Plant Utilisation

Month Plant Operation (% of total capacity)

January 25

February 13

March 26

April 27

May 32

June 87

July 72

August 100

September 96

October 100

November 65

December 95


36

5 NOTIFIED EVENTS During 2010 there were eight occasions where the site catchment system (including treatment plant) was unable to contain all contaminated run-off on site. In each instance overflow events occurred following large rainfall events, when the Dawesley Creek diversion and site catchment system are at capacity and the pump back system is unable to cope with such continual high flows. It should be noted that when any contaminants are released they are often diluted by clean flows through the site and capacity flows within Dawesley Creek.

• Overflow at bottom collection pond commenced 1st August 2010 control regained 2nd

• Overflow at bottom collection pond commenced 15

August 2010

th August 2010 control regained 16th

• Overflow at bottom collection pond commenced 24 August 2010

th August 2010 control regained 25th

• Overflow at top of town (Peggy Buxton Rd) and bottom collection pond commenced 26

August 2010

th August control regained 27th


August 2010

rd September 2010 control regained 7th

• Overflow at bottom collection pond commenced 10 September 2010

th September 2010 control regained 11th


September 2010

th September 2010 control regained 15th

• Overflow at bottom collection pond commenced 7 September 2010

th December 2010 control regained 8th

Overflows are managed in accordance with the draft Contingency Plan for the site. PH values are measured at downstream locations and reported to the Environment Protection Authority.

December 2010

Note: During 2007 and 2008 no events were recorded prompting notification to EPA. Prior to 2007 it is understand that it was not customary practice that overflow events be recorded and/or notified.


37

6 CONCLUSION AND PROPOSED ACTIONS

6.1 Conclusion

The results of the water quality monitoring program for 2010 demonstrate the following:

• There is consistency with 2010 results as compared to other years (post diversion) which are markedly improved over pre-diversion values.

• Rainfall measured in 2010 was approximately 17% above the long-term average. This resulted in a marked increase in the volume of water treated during 2010.

• Flushes of low pH and high metals are observed downstream of the mine following the drier summer months, but can also be observed to varying degrees sporadically in the wetter months.

• Water quality downstream of the mine generally improves (relative to analytes measured against ANZECC guidelines) with distance (from the mine) in terms of livestock standards. Exceeded trigger values generally relate to sulphate, aluminium and cadmium.

• Eight events were notified to EPA (largely resulting from overflows during or subsequent to periods of heavy rain)

6.2 Actions from 2010

The following two action items were proposed within the 2009 Monitoring Report (Finalised May 2010):

1. Install telemetry at both the upstream and downstream weirs

Completed.

2. Install a velocity meter within the diversion pipe in order to effectively gauge the upstream station. This information will also be used to back calculate data (post installation of the diversion) in order to verify calculated values.

Completed.

6.3 Proposed Actions for 2011

In addition to normal hydrological and biological monitoring it is also planned in 2011 to:


38

1. Undertake a review of the existing flow monitoring network and program. This is being completed in order to take account of the number of changes to the system since installation in the late 1980’s and provide confidence in the resultant quality of data.


39

7 REFERENCES

(ANZECC) Australian and New Zealand Environment and Conservation Council (2000) Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Environment Australia Publications.

Environment Protection Authority (2007) EPA Guidelines. Regulatory Monitoring and Testing. Reporting Requirements. August 2007


40

Appendices


41

Table 1. Brukunga Upstream (Peggy Buxton Road) (ref. 4728)

Appendix 1 Grab Sampling

DATE pH TDS by ECSULPHATE Al As Cd Cr Cu Fe Pb Mn Ni Znunits total mg/l total mg/l total mg/l total mg/L total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l

15-Jan-02 7.7 1,100 81.5 0.633 <0.0005 <0.003 0.003 1.03 0.001 0.053 0.0051 0.01412-Feb-02 7.7 1,100 66.3 <0.200 <0.0005 <0.003 0.004 1.33 0.0016 0.0447 0.0054 0.01513-Mar-02 7.7 1,300 92.2 4.79 <0.0005 <0.003 0.002 11.4 0.0006 0.0415 0.0073 0.05616-Apr-02 7.8 1,000 65.9 0.618 <0.0005 <0.003 0.008 1.05 0.0023 0.112 0.0044 0.05414-May-02 8.0 1,400 82.0 0.313 <0.0005 <0.003 0.003 0.418 0.0007 0.0256 0.0043 0.00812-Jun-02 7.6 970 72.9 0.807 <0.0005 <0.003 0.004 1.64 0.0009 0.0547 0.0040 0.01616-Jul-02 7.5 820 68.6 0.274 <0.0005 <0.003 0.004 0.578 <0.0005 0.0214 0.0038 0.015

15-Aug-02 7.6 830 69.1 0.216 <0.0005 0.004 0.003 0.519 <0.0005 0.0235 0.0063 0.00911-Sep-02 7.4 850 76.9 0.533 <0.0005 <0.003 0.002 2.21 0.0012 0.0839 0.0041 0.01215-Oct-02 7.7 940 58.7 0.291 <0.0005 <0.003 0.003 0.688 0.0006 0.02 0.0029 0.00912-Nov-02 7.6 960 61.4 0.275 <0.0005 <0.003 0.005 0.516 0.0013 0.035 0.0042 0.03912-Dec-02 7.6 1,000 67.7 1.73 <0.0005 0.004 0.004 3.730 0.0033 0.127 0.0063 0.02520-Jan-04 7.7 970 88.7 0.570 <0.0005 <0.003 0.002 0.921 0.0013 0.0423 0.007 0.00817-Feb-04 7.7 1,000 62.7 0.51 <0.0005 0.005 0.005 0.815 0.001 0.0706 0.0059 0.0110-Mar-04 7.7 1,100 64.2 0.338 <0.0005 <0.003 <0.001 0.727 0.0006 0.0605 0.0042 <0.00315-Apr-04 7.8 1,000 135.0 0.319 <0.0005 <0.003 0.001 0.446 <0.0005 0.0209 0.0036 0.00319-May-04 7.7 1,300 153.0 0.373 <0.0005 0.008 0.004 0.569 0.0006 0.0389 0.0049 0.01818-Jun-04 7.7 970 101.0 1.050 <0.0005 0.004 0.003 1.46 0.0007 0.0435 0.0049 0.01214-Jul-04 7.6 790 78.0 0.649 <0.0005 0.005 0.014 1.31 0.001 0.0385 0.0058 0.019

19-Aug-04 7.3 950 85.1 0.421 <0.0005 <0.003 0.004 1.11 0.0007 0.0874 0.0037 0.02415-Sep-04 7.5 940 81.7 0.440 <0.0005 <0.003 0.003 1.2 0.0009 0.0661 0.0059 0.01219-Oct-04 8.0 1,200 104.0 0.273 <0.0005 0.004 0.004 0.792 0.0007 0.1003 0.0052 0.01309-Nov-04 7.8 870 63.8 0.848 <0.0005 0.006 0.004 1.59 0.0011 0.0642 0.0045 0.01315-Dec-04 7.7 840 54.6 0.827 <0.0005 <0.003 0.002 1.010 <0.0005 0.033 0.004 0.00517-Apr-06 7.8 1,130 64.2 0.322 <0.0005 0.003 0.003 1.44 0.0008 0.1756 0.0063 0.01422-May-06 7.5 810 44.4 0.356 <0.0005 0.006 0.0026 0.594 <0.0005 0.0262 0.0035 0.00913-Jun-06 7.6 849 65.4 0.238 <0.0005 0.004 0.0016 0.519 <0.0005 0.0372 0.004 0.00717-Jul-06 7.5 980 59.7 0.149 <0.0005 0.004 0.0031 0.79 0.0005 0.2101 0.0043 0.01

15-Aug-06 7.4 1,100 81.9 0.341 <0.0005 0.004 0.0014 0.94 <0.0005 0.2892 0.0033 0.00512-Sep-06 7.7 850 43.2 0.327 <0.0005 0.004 0.0047 0.805 0.0094 0.0203 0.0032 0.01512-Oct-06 7.8 910 52.8 0.457 <0.0005 <0.003 0.0017 0.928 0.0006 0.0281 0.0028 0.00715-Nov-06 7.8 1,000 27.9 0.372 <0.0005 0.003 0.0026 1 0.0005 0.0681 0.003 0.00713-Dec-06 7.9 1,400 22.2 1.890 <0.0005 0.004 0.003 3.73 0.0017 0.1127 0.0039 0.01716-Jun-08 7.9 1,100 84.9 0.169 <0.0005 <0.003 0.0021 1.31 <0.0005 0.0364 0.0085 0.01215-Jul-08 7.4 970 91.8 0.280 <0.005 0.005 0.006 1.432 <0.010 0.042 0.011 0.0322-Jul-08 7.3 850 70.8 0.487 <0.005 0.001 <0.005 1.346 <0.010 0.044 0.008 0.032

28-Aug-08 7.5 920 91.2 0.401 <0.005 0.001 <0.005 1.26 <0.010 0.107 0.009 0.05815-Sep-08 7.4 910 105 0.241 0.004 <0.005 <0.001 <0.005 1.121 <0.010 0.093 0.01 0.03515-Oct-08 7.8 870 81.6 0.225 0.010 <0.005 0.001 <0.005 0.831 <0.010 0.053 0.009 0.01917-Nov-08 7.7 940 45.6 0.164 0.031 <0.005 <0.001 <0.005 0.591 <0.01 0.039 0.007 0.0117-May-10 7.7 1,100 70.8 0.352 0.0097 <0.0001 0.0011 0.005 2.517 0.0005 0.041 0.0105 0.0216-Jun-10 7.5 790 52.2 0.373 0.0066 <0.0001 0.0009 0.0019 1.094 0.0003 0.031 0.0053 0.01419-Jul-10 7.2 700 58.5 0.428 0.0037 0.0001 0.0001 0.0053 1.215 0.0003 0.098 0.0054 0.0245

16-Aug-10 6.9 510 39 1.147 0.0019 <0.0001 0.0018 0.005 1.367 0.0008 0.053 0.0049 0.022515-Sep-10 7.2 490 48.7 1.244 0.0021 <0.0001 0.0018 0.0038 1.844 0.0008 0.076 0.003 0.016218-Oct-10 7.6 970 94.8 0.440 0.0047 <0.0001 0.0011 0.0013 1.585 0.0002 0.125 0.0055 0.01415-Nov-10 7.3 920 98.4 0.394 0.0058 <0.0001 0.0014 0.0033 1.651 0.0006 0.124 0.0056 0.014616-Dec-10 7.2 1,000 105 0.934 0.0061 0.0001 0.0016 0.0023 2.37 0.0005 0.3 0.005 0.0144

For Aquatic Ecosystems 90% Protection Level. Adjusted for Hardness (Based on ~160mg/L as CaCo3, 150mg/L used for calculations of Cd, Cu, Pb, Ni, Zn) <6.5/>9.0 0.08 0.042 0.00168 0.00702 0.0456 2.5 0.0507 0.0585

Irrigation <6.0/>8.5 5 0.1 0.01 0.1 0.2 0.2 2 0.2 0.2 2.00x10Livestock 2000 1000 5 0.5 0.01 1 0.4 0.1 1 20.00x10


42

Table 2. Brukunga Downstream (ref. 3158)

DATE pH TDS by ECSULPHATEALUMINIUMARSENIC CADMIUMCHROMIUM COPPER IRON LEAD MANGANES NICKEL ZINCunits total mg/l total mg/l total mg/l total mg/L total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l

15-Jan-2002 3.4 1,700 1,420 112.000 0.036 0.004 0.061 5.340 0.0008 10.20 0.371 5.520013-Feb-2002 3.6 1,700 1,050 29.800 0.016 <0.003 0.025 3.590 0.0006 4.58 0.233 3.720013-Mar-2002 3.2 2,500 2,440 208.000 0.030 0.014 0.058 15.700 0.0012 16.80 0.538 10.100016-Apr-2002 3.4 1,700 1,250 69.300 0.011 <0.003 0.026 3.000 0.0006 9.72 0.416 5.040012-Jun-2002 4.4 1,300 602 13.100 0.012 <0.003 0.018 6.890 0.0005 2.96 0.14 2.000016-Jul-2002 4.2 1,200 840 33.300 0.018 0.005 0.025 9.080 <0.0005 3.40 0.148 2.540013-Aug-2002 4.4 1,100 730 26.800 0.007 <0.003 0.009 9.790 <0.0005 3.63 0.0562 1.686011-Sep-2002 4.5 1,000 545 29.000 0.016 <0.003 0.022 18.200 0.0012 3.30 0.1589 2.250015-Oct-2002 4.3 1,600 1,137 32.000 0.004 <0.003 0.006 14.300 0.0005 5.29 0.0491 2.731012-Nov-2002 3.8 1,300 817 27.500 0.009 <0.003 0.015 2.310 <0.0005 4.70 0.1766 2.872012-Dec-2002 3.4 1,500 1,120 56.900 0.012 <0.003 0.016 9.870 0.0007 6.40 0.2507 3.801020-Jan-2004 7 1100 277 1.230 0.002 <0.003 0.005 1.340 <0.0005 0.56 0.0327 0.133017-Feb-2004 6.9 1300 423 1.000 0.003 <0.003 0.005 2.060 <0.0005 1.20 0.0462 0.308010-Mar-2004 6.3 1800 774 1.240 0.002 <0.003 0.002 1.120 <0.0005 1.05 0.0288 0.154015-Apr-2004 7.2 1300 564 1.150 0.002 <0.003 0.003 0.969 <0.0005 0.70 0.024 0.110019-May-2004 6.2 2000 1930 2.250 0.005 0.006 0.003 2.540 <0.0005 1.83 0.0352 0.733018-Jun-2004 4 1300 1710 129.000 0.016 0.008 0.090 7.190 0.0022 8.63 0.3819 9.820014-Jul-2004 7 1300 806 2.500 0.003 <0.003 0.008 1.300 <0.0005 1.24 0.0415 0.209019-Aug-2004 6.4 1300 662 3.340 0.008 <0.003 0.011 1.960 <0.0005 3.57 0.0388 0.705015-Sep-2004 7 1300 574 5.210 0.004 <0.003 <0.001 2.010 <0.0005 0.86 0.0269 0.278019-Oct-2004 6.8 1600 956 2.910 0.008 <0.003 0.010 1.600 <0.0005 2.92 0.045 0.56609-Nov-2004 7.4 1200 535 1.250 0.002 0.004 0.007 0.680 <0.0005 1.60 0.0223 0.0970

15-Dec-2004 7.3 960 217 0.602 0.001 <0.003 0.006 0.485 <0.0005 0.49 0.0293 0.039011-Jan-2006 7 1210 342 1.550 0.007 <0.003 0.018 3.490 <0.0005 1.81 0.0616 0.333017-Apr-2006 7.5 1130 279 3.066 0.003 <0.003 0.007 3.740 0.0005 1.32 0.0243 0.237022-May-2006 7.4 844 97.5 28.900 0.009 0.006 0.012 20.500 0.0039 1.08 0.0212 1.350013-Jun-2006 7.4 899 125 3.456 0.001 0.004 0.003 2.300 <0.0005 0.39 0.0158 0.167017-Jul-2006 6.4 1300 747 9.890 0.007 0.004 0.013 9.810 0.0007 1.68 0.0492 0.875015-Aug-2006 7.4 1100 1550 4.060 0.009 <0.003 0.010 1.940 <0.0005 7.71 0.0573 1.250012-Sep-2006 7.4 1100 369 1.700 0.002 0.004 0.005 0.755 0.0176 1.91 0.0201 0.103012-Oct-2006 6.9 1800 1440 1.350 0.004 <0.003 0.003 0.937 <0.0005 <0.0005 0.0437 0.328015-Nov-2006 7 1500 804 1.270 0.002 <0.003 0.004 1.150 <0.0005 6.16 0.0358 0.199016-Jun-2008 7.1 1400 627 1.430 0.0013 <0.003 <0.0010 1.430 <0.0005 0.9023 0.0181 0.114021-Jul-2008 6.8 1100 546 5.174 <0.005 0.002 0.009 3.259 <0.01 0.648 0.025 0.315002-Sep-2008 6.6 1300 687 9.115 <0.005 0.001 0.009 3.007 <0.01 1.43 0.035 0.362015-Sep-2008 7 1200 573 1.874 <0.001 <0.005 <0.001 <0.005 1.202 <0.01 0.543 0.023 0.132015-Oct-2008 7.4 980 253 1.148 <0.001 <0.005 <0.001 0.014 1.245 <0.01 0.709 0.028 0.092017-Nov-2008 7.3 1000 146 0.490 <0.001 <0.005 <0.001 <0.005 1.084 <0.01 0.325 0.02 0.039017-May-2010 6.8 1500 561 4.188 0.0029 0.0015 0.000 0.0059 4.032 0.0003 0.702 0.028 0.280916-Jun-2010 6.9 1600 1150 1.341 0.0022 0.0016 0.001 0.0023 1.686 <0.0001 2.06 0.0219 0.146719-Jul-2010 7 1000 480 2.410 0.0027 0.0020 0.001 0.0046 1.262 0.0002 0.558 0.0195 0.160916-Aug-2010 4.1 930 654 67.250 0.002 0.0319 0.003 0.0633 30.490 0.0006 2.6 0.0707 2.631015-Sep-2010 6.2 630 244 11.070 0.0018 0.0043 0.002 0.0158 3.978 0.0007 0.653 0.0189 0.468518-Oct-2010 7.2 1200 522 2.527 0.0017 0.0026 0.000 0.0061 1.468 <0.0001 0.721 0.0201 0.176015-Nov-2010 7 1780 227 2.329 0.0020 0.0035 0.001 0.0092 1.162 0.0001 0.755 0.0263 0.178630-Dec-2010 4.7 1700 1630 10.780 0.0012 0.0110 0.000 0.0272 6.335 <0.0001 9.7 0.0388 1.1600




43

Table 3. Melbourne Bridge (ref. 1951)

DATE pH TDS by ECSULPHATEALUMINIUMARSENIC CADMIUMCHROMIUM COPPER IRON LEAD MANGANES NICKEL ZINCunits total mg/l total mg/l total mg/l total mg/L total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l

15-Jan-2002 4.1 1,400 837 30.00 0.0086 <0.003 0.0140 1.380 0.0011 5.0100 0.0968 2.920012-Feb-2002 3.8 1,900 864 27.30 0.0133 <0.003 0.0250 2.310 0.0021 5.6400 0.2930 3.770013-Mar-2002 3.8 2,400 1,710 76.20 0.0106 0.0080 0.0180 2.130 0.0016 11.1000 0.3410 14.600016-Apr-2002 3.5 2,200 1,830 104.00 0.0140 <0.030 0.0280 3.030 0.0033 11.9000 0.3460 5.920014-May-2002 3.5 2,400 1,920 99.40 0.0073 <0.003 0.0160 6.670 0.0022 11.9000 0.2940 3.710012-Jun-2002 3.7 1,600 1,160 51.00 0.0206 <0.003 0.0310 1.200 0.0015 6.6000 0.2800 3.730016-Jul-2002 3.8 1,400 1,068 41.90 0.0223 <0.003 0.0320 0.863 0.0011 4.3300 0.1840 3.350013-Aug-2002 4 1,200 844 29.20 0.0071 <0.003 0.0090 0.429 <0.0005 5.0600 0.0758 3.193011-Sep-2002 4 1,200 689 15.30 0.0142 <0.003 0.0150 0.421 0.0009 3.5900 0.1597 2.160015-Oct-2002 4 1,300 684 21.00 0.0062 <0.003 0.0070 0.500 0.0010 4.7000 0.0582 2.425012-Nov-2002 3.7 1,500 952 16.20 0.0105 <0.003 0.0110 1.780 0.0011 4.6260 0.1583 2.095012-Dec-2002 3.5 1,600 1,007 20.10 0.0059 <0.003 0.0070 2.430 0.0014 5.3970 0.1908 1.827020-Jan-2004 5.2 1,400 614 1.08 0.0010 <0.003 0.0030 4.740 <0.0005 2.1860 0.0344 0.157017-Feb-2004 4.2 1,900 896 2.01 0.0010 <0.003 0.0020 5.500 <0.0005 3.3730 0.0351 0.171015-Apr-2004 6.1 1500 710 0.139 0.0006 <0.003 <0.001 0.588 <0.0005 1.3840 0.0239 0.11119-May-2004 4.4 1,500 766 0.68 0.0011 0.0070 0.0020 0.537 <0.0005 1.9430 0.0412 0.370018-Jun-2004 6 1,400 822 0.30 0.0031 <0.003 0.0020 0.213 <0.0005 1.3930 0.0426 0.454014-Jul-2004 7.1 1,300 769 0.46 0.0016 <0.003 0.0090 0.518 <0.0005 1.6360 0.0374 0.132019-Aug-2004 6.9 1,100 508 1.53 0.0059 <0.003 0.0060 1.640 <0.0005 2.7240 0.0334 0.416019-Sep-2004 7.3 1,200 469 0.82 0.0019 <0.003 <0.001 1.150 <0.0005 1.0140 0.0299 0.125019-Oct-2004 6.2 1,600 854 0.22 0.0031 <0.003 0.0040 2.730 <0.0005 2.1590 0.0567 0.41609-Nov-2004 7.3 1,100 327 0.60 0.0009 0.0050 0.0050 1.430 <0.0005 0.8594 0.0238 0.0680

16-Dec-2004 7.2 1,200 544 0.45 0.0009 <0.003 0.0040 1.020 <0.0005 0.9207 0.0351 0.082011-Jan-06 7.3 1,240 417 0.23 <0.0005 <0.003 0.0025 3.760 <0.0005 2.2250 0.0193 0.096017-Apr-06 7.5 1,180 282 1.25 0.0021 <0.003 0.0056 4.310 <0.0005 1.0660 0.0178 0.130022-May-06 7.5 988 237 1.07 0.0013 0.0050 0.0034 2.230 <0.0005 0.6475 0.0185 0.124013-Jun-06 7.4 1,210 519 4.39 0.0013 0.0030 0.0026 1.440 <0.0005 1.1210 0.0227 0.138017-Jul-06 7.2 1,300 678 0.47 0.0035 0.0030 0.0044 1.080 <0.0005 1.9480 0.0425 0.278015-Aug-06 6.9 1,500 903 0.07 0.0042 0.0040 0.0031 0.371 <0.0005 2.5830 0.0445 0.429012-Sep-06 7.7 1,000 289 0.34 0.0005 <0.003 0.0041 0.753 <0.0005 0.3967 0.0178 0.050012-Oct-06 7.1 1,400 792 0.13 0.0008 <0.003 0.0016 0.580 <0.0005 0.8521 0.0136 0.056015-Nov-06 7.4 1,100 282 0.10 <0.0005 <0.003 0.0029 0.864 <0.0005 0.1960 0.0104 0.014013-Dec-06 7.5 1,500 537 0.05 <0.0005 <0.003 <0.0010 0.424 <0.0005 <0.0005 0.0101 0.015016-Jun-08 7.4 1400 525 1.20 0.0080 <0.003 0.0082 1.570 0.0007 1.7770 0.0270 0.390021-Jul-08 7.2 1200 552 1.177 0.0050 <0.001 0.0090 1.439 <0.010 1.0600 0.0280 0.37002-Sep-08 6.6 1400 795 0.164 0.0050 <0.001 0.0050 0.148 <0.01 1.1500 0.0320 0.442015-Sep-08 6.8 1500 1100 0.131 <0.001 0.0060 <0.001 <0.005 0.209 <0.010 1.3000 0.0370 0.561015-Oct-08 6.7 1500 217 0.506 <0.001 <0.005 0.0020 <0.005 0.705 <0.010 0.2460 <0.0005 0.029017-Nov-08 6.8 1200 435 0.051 0.0120 <0.005 <0.001 <0.005 0.688 <0.01 0.5790 0.0140 0.049016-Jun-10 7.1 1300 582 0.345 0.0008 0.0080 0.0002 0.0079 0.551 0.0002 0.4720 0.0280 0.493519-Jul-10 6.9 1000 492 0.931 0.0007 0.0100 0.0003 0.0102 0.666 0.0002 0.9860 0.0372 0.748016-Aug-10 4.5 800 296 9.727 0.0008 0.0130 0.0007 0.0175 5.193 0.0002 1.0100 0.0459 1.371015-Sep-10 4.4 610 250 14.780 0.0014 0.0095 0.0022 0.0236 4.883 0.0007 0.9050 0.0298 0.971218-Oct-10 7.4 1300 462 1.471 0.0011 0.0042 0.0004 0.0082 1.858 0.0003 0.8480 0.0287 0.315015-Nov-10 7.1 1200 405 0.692 0.0006 0.0038 0.0002 0.0080 1.058 0.0002 0.8660 0.0288 0.222216-Dec-10 6.8 1400 726 0.777 0.0009 0.0034 0.0003 0.0067 1.791 0.0002 1.8900 0.0285 0.2455




44

Table 4. Downstream Nairne Creek Junction (ref. 1822)

DATE pH TDS by ECSULPHATEALUMINIUMARSENIC CADMIUMCHROMIUMCOPPER IRON LEAD MANGANES NICKEL ZINCunits total mg/l total mg/l total mg/l total mg/L total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l

15-Jan-02 6.8 1,600 681 0.086 <0.0005 <0.003 0.001 0.439 <0.0005 2.484 0.0278 0.05712-Jun-02 7.5 1,000 239 0.199 0.0014 <0.003 0.007 0.307 0.0006 0.1320 0.0114 0.10316-Jul-02 4.4 1,400 799 15.00 0.0174 <0.003 0.025 0.246 <0.0005 3.99 0.1300 2.38

13-Aug-02 4.6 1,300 708 9.28 0.0076 <0.003 0.011 0.134 <0.0005 3.719 0.074 2.63711-Sep-02 6.6 1,200 588 0.292 0.0098 <0.003 0.006 0.065 <0.0005 3.315 0.0958 2.64515-Oct-02 6.8 1,300 525 0.248 0.0026 <0.003 0.004 0.138 <0.0005 2.677 0.0443 0.48312-Nov-02 6.4 1,500 670 0.242 <0.005 <0.003 0.001 1.290 <0.0005 3.403 0.0360 0.12412-Dec-02 6.8 1,300 511 0.084 <0.005 <0.003 0.001 0.505 <0.0005 0.902 0.0205 0.06018-Jun-04 7 790 266 1.73 0.0041 0.004 0.009 1.68 0.0017 0.3913 0.0168 0.25614-Jul-04 5.4 1,300 730 1.63 0.0222 <0.003 0.009 0.146 <0.0005 2.281 0.0843 1.889

19-Aug-04 6.1 1,100 368 2.01 0.0154 <0.003 0.017 0.492 <0.0005 1.713 0.0884 1.55419-Sep-04 7.4 1,300 394 0.289 0.0045 <0.003 <0.001 0.304 <0.0005 1.141 0.0379 0.36119-Oct-04 6.7 1,600 546 0.113 0.0024 <0.003 0.006 0.513 <0.0005 1.075 0.0353 0.29409-Nov-04 7.2 1,700 527 0.349 0.0018 0.005 0.006 0.672 <0.0005 0.6175 0.0226 0.11415-Dec-04 7 1,600 665 0.258 0.0014 <0.003 0.003 0.557 <0.0005 0.1818 0.0272 0.08717-Apr-06 7.5 1,430 444 0.041 0.0011 <0.003 0.004 0.143 <0.0005 0.2529 0.0097 0.05522-May-06 7 1,610 783 0.711 0.003 0.007 0.0033 1.18 0.0006 1.648 0.0259 0.28413-Jun-06 7.6 1,070 360 0.063 <0.0005 <0.003 0.0022 0.241 <0.0005 0.044 0.008 0.03417-Jul-06 5.4 1,100 474 2.12 0.0107 <0.003 0.0087 0.191 <0.0005 2.585 0.065 1.18

15-Aug-06 7.4 1,300 570 0.081 0.001 0.003 0.0025 0.241 <0.0005 0.6463 0.0169 0.07512-Sep-06 7.5 1,100 408 0.098 <0.0005 <0.003 0.0032 0.221 <0.0005 0.1097 0.0087 0.02512-Oct-06 7.2 1,300 507 0.224 0.0005 <0.003 0.0019 0.475 0.0008 <0.0005 0.0075 0.04416-Jun-08 7.4 770 179 0.079 0.0007 <0.003 0.0045 0.366 <0.0005 0.0669 0.0125 0.10421-Jul-08 7 1,200 525 0.29 <0.005 <0.001 0.008 0.469 <0.010 0.184 0.02 0.286

02-Sep-08 7.5 1,100 306 0.179 <0.005 <0.001 0.006 0.481 <0.01 0.045 0.011 0.12115-Sep-08 7.1 1,300 465 0.067 <0.001 <0.005 <0.001 <0.005 0.348 <0.01 0.062 0.013 0.12915-Oct-08 7.1 1,500 624 0.058 <0.001 <0.005 <0.001 <0.005 0.839 <0.01 1.5 0.018 0.18616-Jun-10 7.4 780 186 0.049 0.0006 0.0011 0.0001 0.0063 0.227 <0.0001 0.069 0.0084 0.096117-Jul-10 7.5 740 87 0.385 0.0028 0.0001 0.0008 0.0067 0.533 0.0005 0.013 0.0031 0.0133

16-Aug-10 6.8 950 378 0.784 0.0007 0.0050 0.0007 0.0053 0.755 0.0005 0.661 0.0274 0.443515-Sep-10 7.1 510 129 5.192 0.0014 0.0027 0.0023 0.0107 3.031 0.0009 0.428 0.016 0.240618-Oct-10 8.1 1,500 468 0.206 0.0014 0.0028 0.0004 0.0032 0.835 0.0005 0.923 0.0266 0.186915-Nov-10 7.1 1,800 744 0.062 0.0006 0.0012 0.0002 0.002 0.734 <0.0001 1.13 0.0221 0.093516-Dec-10 6.8 1,500 675 0.329 0.0006 0.0006 0.0075 0.0022 0.457 <0.0001 3.14 0.0624 1.653




45

Table 5. South East Freeway (ref. 1952)


15-Jan-2002 3.7 2,500 1040 5.15 0.0020 <0.003 0.010 8.030 0.001 5.900 0.066 1.27016-Jul-2002 4.6 1300 712 5.02 0.0177 <0.003 0.014 0.060 <0.0005 3.46 0.1060 2.25

13-Aug-2002 4.9 1200 598 2.61 0.0096 <0.003 0.009 0.056 <0.0005 3.306 0.074 2.36211-Sep-2002 5.6 1200 526 0.47 0.0077 <0.003 0.007 0.081 <0.0005 2.55 0.0678 1.0815-Oct-2002 5.8 1400 615 0.30 0.0054 <0.003 0.004 <0.030 <0.0005 2.355 0.0425 0.8312-Nov-2002 5.9 1,600 790 0.31 0.0016 <0.003 0.005 0.184 <0.0005 3.384 0.0418 0.54714-Jul-2004 6.5 1300 603 0.078 0.0175 <0.003 0.007 0.038 <0.0005 1.408 0.0794 1.108

19-Aug-2004 6.1 1000 352 0.689 0.0134 <0.003 0.003 0.249 <0.0005 1.522 0.0178 1.32719-Sep-2004 6.9 1300 439 0.216 0.007 <0.003 <0.001 0.175 <0.0005 1.768 0.0576 0.75919-Oct-2004 6.3 1500 543 0.068 0.0014 <0.003 0.005 0.326 <0.0005 1.383 0.0238 0.2229-Nov-2004 6.4 1700 584 0.269 0.0044 0.004 0.006 0.195 <0.0005 1.06 0.0291 0.319

15-Dec-2004 6.9 1400 506 0.185 0.0015 0.003 0.005 0.744 <0.0005 0.3632 0.0224 0.10722-May-2006 7 1330 456 0.051 0.001 0.005 0.0052 0.126 <0.0005 0.0264 0.0065 0.04913-Jun-2006 7.3 1240 531 0.189 0.001 <0.003 0.0047 0.368 <0.0005 0.0847 0.0082 0.07817-Jul-2006 6.1 980 441 0.387 0.0082 <0.003 0.0055 0.052 <0.0005 1.974 0.0521 0.94

15-Aug-2006 6.8 1200 534 0.037 0.0027 <0.003 0.0048 0.073 <0.0005 0.6577 0.0159 0.16912-Sep-2006 7.4 1200 453 0.064 0.0005 <0.003 0.0039 0.169 <0.0005 0.0709 0.0086 0.03212-Oct-2006 6.9 1200 450 0.025 0.0008 <0.003 0.0032 0.152 <0.0005 0.3395 0.0051 0.04716-Jun-2008 7.2 1300 504 0.662 0.0104 <0.003 0.0339 0.66 0.0005 0.396 0.0369 0.54421-Jul-2008 7 970 384 0.071 <0.005 <0.001 0.008 0.197 <0.01 0.035 0.012 0.167

02-Sep-2008 7.2 1300 534 0.044 <0.005 <0.001 0.006 0.188 <0.01 0.046 0.01 0.1215-Sep-2008 7.4 1400 612 0.043 <0.001 <0.005 <0.001 0.006 0.181 <0.01 0.067 0.011 0.13315-Oct-2008 6.9 1600 717 0.021 <0.001 <0.005 <0.001 0.01 0.422 <0.01 0.505 0.01 0.09619-Jul-2010 6.9 1000 414 0.322 0.0004 0.0025 0.0003 0.011 0.482 0.0002 0.073 0.0109 0.1324

16-Aug-2010 6.8 940 378 0.889 0.0006 0.004 0.0008 0.0091 0.972 0.0006 0.505 0.0256 0.333615-Sep-2010 7.4 520 128 5.602 0.0014 0.0025 0.0023 0.0108 3.319 0.001 0.423 0.015 0.222318-Oct-2010 7.4 1600 489 0.16 0.0011 0.0027 0.0003 0.0053 0.869 0.0001 0.917 0.022 0.149515-Nov-2010 7.2 1800 624 0.027 0.0005 0.001 0.0007 0.0052 0.33 <0.0001 1.04 0.0149 0.079716-Dec-2010 7.4 1400 471 0.066 0.0005 0.0003 <0.0001 0.004 0.828 <0.0001 0.667 0.009 0.0222For Aquatic Ecosystems 90% Protection Level. Adjusted for Hardness (Based on ~275mg/L as CaCo3, 210mg/L used for calculations of Cd, Cu, Pb, Ni, Zn)

<6.5/>9.0 0.08 0.042 0.00228 0.00936 0.0708 2.5 0.0676 0.104Irrigation <6.0/>8.5 5 0.1 0.01 0.1 0.2 0.2 2 0.2 0.2 2.00x10Livestock 2000 1000 5 0.5 0.01 1 0.4 0.1 1 20.00x10


46

Table 6. Mount Barker Creek (ref. 1807)


15-Jan-2002 7.9 1,500 225 0.292 <0.0005 <0.003 0.002 0.168 0.0006 0.3000 0.0038 0.01412-Feb-2002 8.5 8,800 484 0.264 <0.0005 <0.003 <0.001 0.246 <0.0005 0.0122 0.0025 <0.00313-Mar-2002 7.9 2,100 263 0.226 <0.0005 <0.003 0.002 0.191 0.0005 0.3060 0.0045 0.01516-Apr-2002 7.8 2,600 281 0.499 0.0007 <0.003 0.008 0.369 0.0019 0.3220 0.0043 0.02614-May-2002 8.1 2,900 283 2.030 0.0017 0.004 0.007 1.930 0.0054 0.7660 0.0106 0.16612-Jun-2002 7.8 1,600 172 0.141 0.0007 <0.003 0.004 0.186 0.0011 0.1200 0.0046 0.0716-Jul-2002 7.6 1,200 154 0.401 0.0011 <0.003 0.003 0.424 0.0013 0.1320 0.0092 0.113

13-Aug-2002 8.2 5,000 464 0.112 <0.0005 <0.003 0.003 0.513 <0.0005 0.0182 0.0021 <0.00311-Sep-2002 7.7 1,100 198 0.130 0.0006 <0.003 0.001 0.153 0.0006 0.1569 0.0089 0.04915-Oct-2002 8.2 5,400 459 0.126 <0.0005 <0.003 0.002 0.384 <0.0005 0.0239 0.0022 <0.00312-Nov-2002 7.7 1,700 143 0.392 <0.0005 <0.003 0.001 0.263 0.0011 0.4216 0.0065 0.02412-Dec-2002 7.8 1,300 282 0.276 <0.0005 <0.003 <0.001 0.373 0.0008 0.318 0.0062 0.01810-Mar-2004 7.8 2,100 190 0.096 <0.0005 <0.003 <0.001 0.177 <0.0005 0.4532 0.0061 <0.00318-Jun-2004 7.6 600 82 1.29 0.0006 0.004 0.004 1.44 0.0024 0.0775 0.0047 0.06514-Jul-2004 8.4 8,800 868 0.058 <0.0005 0.004 0.004 0.156 <0.0005 0.0227 0.0048 <0.003

19-Aug-2004 7.8 1,600 149 0.063 <0.0005 0.006 0.004 0.14 <0.0005 0.0062 0.0028 <0.00315-Sep-2004 7.6 1,200 264 0.116 0.0015 <0.003 0.004 0.175 <0.0005 0.2856 0.0152 0.10619-Oct-2004 8.1 3,900 325 0.063 <0.0005 0.004 0.005 0.426 <0.0005 0.0416 0.0052 0.00709-Nov-2004 8.1 4,500 390 <0.020 0.001 0.005 0.004 0.457 <0.0005 0.0398 0.005 0.00715-Dec-2004 7.7 1,300 275 0.163 0.0008 0.004 0.002 0.292 <0.0005 0.3755 0.0071 0.01414-Mar-2006 7.9 1,770 121 0.174 <0.0005 <0.003 <0.0010 0.176 <0.0005 0.5408 0.0041 0.00822-May-2006 7.5 1,010 309 0.182 0.0007 0.005 0.0035 0.249 <0.0005 0.0757 0.0048 0.03113-Jun-2006 7.7 1,230 274 0.088 <0.0005 0.003 <0.0010 0.191 <0.0005 0.0687 0.0033 0.01917-Jul-2006 7.7 1,400 218 0.143 <0.0005 <0.003 0.003 0.249 0.0006 0.141 0.007 0.083

15-Aug-2006 7.8 1,500 212 0.057 <0.0005 0.004 0.0021 0.141 <0.0005 0.0955 0.0032 0.0312-Sep-2006 7.8 1,000 197 0.091 <0.0005 <0.003 0.0018 0.12 0.0005 0.0492 0.0032 0.02212-Oct-2006 7.9 1,100 175 0.268 <0.0005 <0.003 0.0011 0.381 0.0008 0.261 0.0029 0.02113-Dec-2006 7.9 1,700 144 0.084 <0.0005 <0.003 <0.0010 0.18 <0.0005 0.5885 0.0034 0.08116-Apr-2008 7.8 1,700 141 0.089 <0.0005 <0.003 0.0021 0.412 0.0005 0.7776 0.0044 0.00816-Jun-2008 7.6 720 122 0.106 <0.0005 <0.003 <0.0010 0.456 <0.0005 0.0779 0.0046 0.0821-Jul-2008 7.3 630 117 1.207 <0.005 0.002 <0.005 1.231 <0.010 0.039 <0.005 0.069

02-Sep-2008 7.6 1,400 165 0.194 <0.005 <0.001 <0.005 0.419 <0.01 0.045 <0.005 0.0515-Sep-2008 7.8 1,300 167 0.079 <0.001 <0.005 <0.001 <0.005 0.259 <0.01 0.057 <0.005 0.04215-Oct-2008 7.6 1,500 198 0.058 <0.001 <0.005 <0.001 <0.005 0.382 <0.01 0.157 <0.005 0.02416-Jun-2010 7.6 980 89 0.066 0.001 0.0001 0.0002 0.001 0.567 0.0003 0.123 0.0029 0.019319-Jul-2010 7.2 870 137 0.831 0.001 0.0003 0.0012 0.0046 1.228 0.0015 0.112 0.0037 0.0382

16-Aug-2010 7.3 530 60 2.307 0.0013 0.0008 0.0017 0.0052 2.242 0.0046 0.078 0.0046 0.058615-Sep-2010 7 450 71 4.163 0.0014 0.0009 0.0023 0.006 2.648 0.002 0.198 0.0073 0.09718-Oct-2010 7.9 1,600 213 0.063 0.0014 0.0005 0.0003 0.0021 0.294 0.0005 0.11 0.0047 0.028615-Nov-2010 7.6 1,400 203 0.145 0.001 0.0001 0.0005 0.0023 0.456 0.0007 0.256 0.0039 0.015916-Dec-2010 7.9 1,100 191 0.382 0.0012 0.0005 0.0006 0.0025 0.766 0.001 0.367 0.0039 0.216For Aquatic Ecosystems 90% Protection Level. Adjusted for Hardness (Based on ~300mg/L as CaCo3, 210mg/L used for calculations of Cd, Cu, Pb, Ni, Zn)

<6.5/>9.0 0.08 0.042 0.00228 0.00936 0.0708 0.0676 0.104Irrigation <6.0/>8.5 5 0.1 0.01 0.1 0.2 0.2 2 0.2 0.2 2.00x10Livestock 2000 1000 5 0.5 0.01 1 0.4 0.1 1 20.00x10


47

Table 7. Bremer River (ref. 1824)


15-Jan-02 7.8 1,700 196 0.153 <0.0005 <0.003 0.001 0.227 <0.0005 0.435 0.0044 0.00812-Feb-02 8 2,100 217 0.361 <0.0005 <0.003 0.001 0.504 0.008 0.683 0.006 0.02213-Mar-02 8.1 2,400 257 0.528 0.0005 <0.003 0.002 0.623 0.0009 0.595 0.0051 0.02116-Apr-02 7.8 2,400 266 0.488 <0.0005 <0.003 0.004 0.545 0.001 0.434 0.005 0.02214-May-02 8.1 2,600 264 0.197 <0.0005 <0.003 0.002 0.24 <0.0005 0.202 0.0046 0.01212-Jun-02 7.8 1,500 206 0.208 0.0005 <0.003 0.002 0.187 <0.0005 0.168 0.0042 0.03416-Jul-02 7.6 1,100 142 0.675 0.0006 <0.003 0.002 0.569 0.0007 0.0732 0.0065 0.048

13-Aug-02 8.5 1,400 180 0.441 <0.0005 <0.003 0.057 0.335 0.0006 0.1441 0.0062 0.03311-Sep-02 8 1,200 159 0.261 <0.0005 <0.003 0.002 0.283 0.0006 0.1648 0.0061 0.02415-Oct-02 7.8 1,300 212 0.232 <0.0005 <0.003 0.001 0.191 <0.0005 0.0886 0.0038 0.00912-Nov-02 7.9 1,500 179 0.173 0.0006 <0.003 0.001 0.148 <0.0005 0.102 0.0033 0.0112-Dec-02 7.9 1,500 137 0.332 <0.0005 <0.003 0.002 0.39 0.0006 0.251 0.0062 0.01710-Mar-04 8 2,400 188 0.131 <0.0005 <0.003 <0.001 0.193 <0.0005 0.3195 0.0052 0.00918-Jun-04 7.5 570 78 1.540 <0.0005 0.005 0.004 1.73 0.0023 0.054 0.0048 0.04914-Jul-04 7.6 1,100 196 0.414 <0.0005 0.003 0.008 0.427 0.0006 0.065 0.0064 0.047

19-Aug-04 7.6 1,100 178 0.869 0.0024 <0.003 0.006 0.393 0.0009 0.3072 0.0183 0.25919-Sep-04 7.8 1,300 210 0.232 0.0008 <0.003 0.003 0.285 <0.0005 0.1735 0.0104 0.05219-Oct-04 8 1,700 229 0.100 <0.0005 <0.003 0.003 0.174 <0.0005 0.2855 0.0057 0.01709-Nov-04 7.9 1,500 160 0.030 0.0006 0.005 0.003 0.168 <0.0005 0.0836 0.0057 0.01515-Dec-04 7.8 1,200 114 0.257 0.0008 0.005 0.003 0.311 <0.0005 0.2663 0.0065 0.01414-Mar-06 8 2,400 152 0.142 <0.0005 <0.003 <0.0010 0.222 <0.0005 0.5902 0.0025 0.00622-May-06 7.5 844 117 2.271 0.0006 0.009 0.005 2.41 0.0025 0.406 0.0062 0.09413-Jun-06 7.6 1,270 300 0.186 <0.0005 <0.003 <0.0010 0.206 <0.0005 0.1324 0.0029 0.01117-Jul-06 7.4 1,500 235 0.183 <0.0005 0.005 0.0027 0.308 0.0006 0.1387 0.0058 0.046

15-Aug-06 8 1,500 205 0.093 <0.0005 0.004 0.0023 0.185 <0.0005 0.0942 0.003 0.01812-Sep-06 7.8 1,400 194 0.551 <0.0005 <0.003 0.0049 0.732 0.0012 0.084 0.004 0.03712-Oct-06 8.8 1,200 174 0.101 <0.0005 <0.003 0.0013 0.174 <0.0005 0.1485 0.0021 0.01113-Dec-06 8.1 2,100 148 0.042 <0.0005 0.003 <0.0010 0.101 <0.0005 0.1978 0.0018 0.00516-Jun-08 7.4 1,300 208 0.041 <0.0005 0.003 <0.0010 0.196 <0.0005 0.0341 0.0033 0.02921-Jul-08 7.1 610 124 1.303 <0.005 0.002 <0.005 1.25 <0.010 0.043 <0.005 0.043

02-Sep-08 7.6 1,600 235 0.145 <0.005 <0.001 <0.005 0.318 <0.01 0.032 <0.005 0.04515-Sep-08 7.9 1,600 225 0.175 <0.001 <0.005 <0.001 <0.005 0.357 <0.01 0.08 <0.005 0.02715-Oct-08 7.7 1,500 217 0.506 <0.001 <0.005 0.002 <0.005 0.705 <0.01 0.246 <0.005 0.02916-Jun-10 7.5 920 106 0.23 0.0009 0.0002 0.0003 0.0021 0.513 0.0003 0.109 0.0032 0.030219-Jul-10 7.2 690 79 1.27 0.0011 0.0002 0.0021 0.0094 1.741 0.0024 0.071 0.0041 0.0304

16-Aug-10 7.2 440 44 2.689 0.0016 0.0004 0.002 0.0054 2.385 0.0048 0.06 0.0042 0.051815-Sep-10 7.4 470 58 3.409 0.0014 0.0005 0.0022 0.0058 2.27 0.0018 0.121 0.0054 0.053318-Oct-10 7.9 1,600 270 0.135 0.0013 0.0003 0.0004 0.0023 0.326 0.0003 0.172 0.0042 0.019115-Nov-10 7.6 1,700 247 0.146 0.0009 0.0001 0.0004 0.0019 0.362 0.0003 0.328 0.0036 0.010716-Dec-10 7.7 1,300 152 0.429 0.0012 0.0001 0.0006 0.0033 0.73 0.0007 0.273 0.0031 0.0118

For Aquatic Ecosystems 90% Protection Level. Adjusted for Hardness (Based on ~275mg/L as CaCo3, 210mg/L used for calculations of Cd, Cu, Pb, Ni, Zn) <6.5/>9.0 0.08 0.042 0.00228 0.00936 0.0708 0.0676 0.104



48

Table 8. Nairne Creek (Control) (ref. 1953)


15-Jan-02 7.5 770 61 0.136 <0.0005 <0.003 0.005 0.131 <0.0005 0.0334 0.0045 0.00812-Feb-02 7.7 700 65 0.248 <0.0005 <0.003 0.004 0.227 0.0006 0.0225 0.0038 0.0113-Mar-02 7.7 730 55 0.344 <0.0005 <0.003 0.003 0.484 0.0006 0.0441 0.0036 0.0116-Apr-02 7.7 700 62 0.273 <0.0005 <0.003 0.004 0.302 0.0006 0.0195 0.003 0.01114-May-02 7.7 700 59 0.186 <0.0005 <0.003 0.004 0.243 <0.0005 0.0088 0.0024 0.00912-Jun-02 7.4 810 157 0.186 <0.0005 <0.003 0.005 0.14 <0.0005 0.0136 0.0021 0.01116-Jul-02 7.6 700 70 0.135 <0.0005 <0.003 0.003 0.271 <0.0005 0.0110 0.0021 0.00913-Aug-02 7.9 510 35 0.126 <0.0005 <0.003 0.002 0.251 <0.0005 0.0066 0.001 0.00711-Sep-02 7.9 730 47 0.144 <0.0005 <0.003 0.005 0.26 <0.0005 0.0116 0.0034 0.01315-Oct-02 7.9 780 54 0.131 <0.0005 <0.003 0.004 0.199 <0.0005 0.0052 0.0022 0.00812-Nov-02 7.5 840 63 0.157 <0.0005 <0.003 0.007 0.234 <0.0005 0.0143 0.0036 0.01412-Dec-02 7.8 840 57 0.119 <0.0005 <0.003 0.003 0.345 <0.0005 0.0246 0.0034 0.00620-Jan-04 7.6 710 118 0.090 <0.0005 <0.003 0.002 0.495 0.0007 0.0689 0.0052 0.00618-Jun-04 7.6 460 106 2.160 <0.0005 0.007 0.009 2.26 0.0029 0.0656 0.0073 0.06914-Jul-04 7.7 700 114 0.441 <0.0005 <0.003 0.007 0.637 <0.0005 0.0102 0.0077 0.04919-Aug-04 7.9 1,000 123 0.667 <0.0005 <0.003 0.007 1.02 0.0006 0.0531 0.0062 0.04615-Sep-04 7.9 1,100 138 0.150 <0.0005 <0.003 <0.001 0.54 <0.0005 0.0783 0.0069 0.02919-Oct-04 9 1,700 268 0.031 <0.0005 0.004 0.004 0.438 <0.0005 0.0861 0.0072 0.00809-Nov-04 8 1,000 117 0.234 <0.0005 0.005 0.004 0.554 <0.0005 0.0321 0.0058 0.01915-Dec-04 8 720 99 0.063 0.0006 <0.003 0.005 0.552 <0.0005 0.0249 0.006 0.01411-Jan-06 7.6 816 84 0.082 <0.0005 <0.003 0.0036 0.108 <0.0005 0.0343 0.0053 0.00614-Mar-06 8.2 594 81 0.125 <0.0005 <0.003 0.0034 0.206 <0.0005 0.003 0.0046 0.00817-Apr-06 7.9 572 61 0.055 <0.0005 <0.003 0.0029 0.17 <0.0005 0.005 0.0029 0.00722-May-06 7.5 567 64 0.180 <0.0005 0.006 0.0032 0.43 <0.0005 0.0174 0.0035 0.01213-Jun-06 7.8 572 46 0.028 <0.0005 0.003 0.0014 0.134 <0.0005 0.0062 0.0024 0.00617-Jul-06 7.5 760 70 0.137 <0.0005 <0.003 0.0038 0.409 0.0006 0.0242 0.0033 0.02315-Aug-06 7.6 720 66 0.079 <0.0005 0.005 0.0035 0.369 <0.0005 0.0133 0.0029 0.01412-Sep-06 7.9 570 46 0.041 <0.0005 <0.003 0.0025 0.183 <0.0005 0.0062 0.0023 0.00612-Oct-06 7.4 690 72 0.047 <0.0005 <0.003 0.0027 0.246 <0.0005 0.007 0.0033 0.0115-Nov-06 7.5 650 64 0.038 <0.0005 <0.003 0.0038 0.148 <0.0005 0.0045 0.0027 0.00713-Dec-06 7.5 780 67 0.032 <0.0005 <0.003 0.0017 0.231 <0.0005 0.0355 0.0042 0.00916-Apr-08 7.5 940 117 0.042 <0.0005 <0.003 0.0087 0.19 <0.0005 0.0087 0.004 0.01616-May-08 7.4 890 115 0.028 <0.0005 <0.003 0.0039 0.139 <0.0005 0.0056 0.0027 0.01216-Jun-08 7.5 690 80 <0.02 <0.0005 <0.003 <0.0010 <0.030 <0.0005 0.0033 0.0021 0.00821-Jul-08 7.3 550 56 0.159 <0.005 <0.001 <0.005 0.363 <0.010 0.006 <0.005 0.01602-Sep-08 7.8 680 66 0.283 <0.005 <0.001 <0.005 0.454 <0.01 0.008 <0.005 0.01415-Sep-08 8.1 630 63 0.254 <0.001 <0.005 <0.001 <0.005 0.848 <0.01 0.011 <0.005 0.01915-Oct-08 7.9 800 85 0.051 0.005 <0.005 <0.001 <0.005 0.222 <0.01 0.005 <0.005 0.09616-Jun-10 7.2 600 59 0.082 0.0046 <0.0001 0.0041 0.0046 0.318 0.0004 0.009 0.0051 0.018119-Jul-10 7.5 740 87 0.385 0.0028 0.0001 0.0008 0.0067 0.533 0.0005 0.013 0.0031 0.013316-Aug-10 7.7 400 25 1.969 0.0019 <0.0001 0.0018 0.0064 2.086 0.0017 0.025 0.0025 0.016815-Sep-10 7.4 380 35 3.801 0.0021 0.00001 0.0021 0.0067 2.437 0.0012 0.033 0.0034 0.026618-Oct-10 8 1,000 99 0.102 0.0035 <0.0001 0.0004 0.0024 0.575 0.0001 0.035 0.003 0.007615-Nov-10 7.8 1,200 105 0.031 0.0052 <0.0001 0.0002 0.0024 0.406 0.0001 0.071 0.0047 0.00616-Dec-10 7.9 780 69 0.181 0.0052 <0.0001 0.0004 0.0035 0.782 0.0003 0.05 0.0036 0.0075




49

APPENDIX 2 ADDITIONAL MONITORING

Table 1. Clarifying Pond Outlet

Table 2. Seepage Pond (Main Collection Point)


15-May-07 9 2,000 2,080 4.9 <0.0005 <0.003 <.0010 0.664 0.0008 0.9694 <0.0005 0.0316-May-08 6 2,600 3,030 0.604 0.0009 <0.003 <0.0010 2.77 <0.0005 29.2 0.0218 0.05616-Jun-08 9.6 1,900 1,630 1.52 <0.0005 <0.003 <0.001 0.691 <0.0005 0.0415 <0.0005 0.01621-Jul-08 9.1 1,900 2,260 3.473 <0.005 <0.001 <0.005 0.524 <0.010 0.114 <0.005 0.02302-Sep-08 7.6 2,100 2,620 1.127 <0.005 0.001 <0.005 0.856 <0.01 3.07 <0.005 0.03115-Sep-08 8.9 2,000 2,250 3.544 <0.001 <0.005 <0.001 <0.005 0.887 <0.01 0.266 <0.005 0.03618-May-09 5.7 2,100 2,360 0.279 <0.001 <0.005 0.002 <0.005 4.397 <0.010 18.1 0.016 0.05310-Jun-09 9.3 1,900 1,970 6.159 <0.001 <0.005 0.001 0.005 1.297 <0.01 0.819 <0.005 0.03620-Jul-09 9.3 1,800 2,020 8.666 0.0008 <0.005 0.002 0.007 2.89 <0.010 0.27 0.007 0.17117-Aug-09 9.2 1,700 1,480 6.801 0.0006 <0.005 <0.001 <0.005 1.267 <0.010 0.105 <0.005 0.06115-Sep-09 9.2 1,800 2,520 14.27 0.0007 0.0001 0.0003 <0.005 0.609 <0.0001 0.074 0.0016 0.022319-Oct-09 9.3 1,800 2,530 8.061 0.0005 0.0002 0.001 <0.005 0.5487 <0.0001 0.042 0.002 0.023316-Nov-09 9.1 1,900 1,620 6.56 0.0007 <0.005 <0.001 <0.005 0.226 <0.01 0.021 <0.005 0.0114-Dec-09 8.7 2,000 1,940 5.549 <0.0003 <0.0001 0.0003 <0.005 0.0213 <0.0001 0.218 0.0004 0.002816-Jun-10 7.6 2,400 2,440 1.322 0.0007 0.0007 0.0003 0.0011 1.363 <0.0001 5.95 0.0028 0.031119-Jul-10 9 1,900 1,910 5.415 0.0006 0.0001 0.0002 0.0031 0.508 <0.0001 0.203 0.0014 0.013816-Aug-10 9.2 1,700 2,100 8.965 0.0008 0.0005 0.0004 0.0059 1.863 <0.0001 0.23 0.0048 0.064815-Sep-10 8.4 2,060 10 0.001 0.0017 0.0016 0.0086 4.21 0.0002 1.19 0.0092 0.205418-Oct-10 9.2 1,800 1,870 7.284 0.0011 0.0006 0.0007 0.0027 1.286 <0.0001 0.288 0.0032 0.066116-Dec-10 8.2 2,400 2,740 2.135 0.0009 0.0018 0.0002 0.0018 0.169 <0.0001 19.7 0.0018 0.0075

For Aquatic Ecosystems 90% Protection Level. Adjusted for Hardness (Based on ~2950mg/L as CaCo3, 400mg/L used for calculations of Cd, Cu, Pb, Ni, Zn <6.5/>9.0 0.08 0.042 0.004 0.0162 0.1602 2.5 0.117 0.135


DATE pH TDS by ECULPHATALUMINIUMARSENIC CADMIUMCHROMIUMCOPPER IRON LEAD MANGANES NICKEL ZINCtotal mg/lotal mg/total mg/l total mg/L total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l total mg/l

13-Mar-02 2.7 6,800 14,000 886 0.111 0.728 0.4100 2,330 0.0014 141 1.739 37.612-Jun-02 2.8 4,600 8,240 333 0.0529 0.066 0.2110 1,950 0.0018 77.5 0.77 19.111-Sep-02 2.8 4,200 321 0.0566 0.11 0.1520 2,080 0.0054 76.7 0.7479 22.512-Dec-02 2.6 5,100 12,100 457 0.145 0.081 0.2950 2,280 0.001 111 1.079 25.610-Mar-04 2.6 5,600 10,200 406 0.0555 0.074 0.1850 2,180 0.0018 117 0.6194 23.618-Jun-04 2.9 2,900 5,470 464 0.357 0.055 0.3460 445 0.0069 42.4 1.222 4415-Sep-04 2.9 3,800 6,560 603 0.2739 0.079 0.4370 611 0.0074 40.75 1.288 34.9415-Dec-04 2.8 4,600 8,930 768 0.0941 0.012 0.0530 935 0.0021 76.36 0.2216 40.4914-Mar-06 2.9 6,170 13,800 1012 0.1074 0.137 0.3861 2,150 0.0013 <0.0005 2.002 42.613-Jun-06 3 4,800 9,510 779 0.0862 0.11 0.2196 1,250 0.0015 72.02 1.495 31.712-Sep-06 3 3,900 6,840 548 0.13 0.055 0.1892 791 0.0033 43.53 1.016 28.513-Dec-06 3 5,500 9,390 258 0.0371 0.029 0.0970 2,350 0.0008 <0.0005 0.5199 <0.00315-Jan-08 2.6 5,500 10,500 681 0.0866 0.042 0.1764 1,950 0.0007 88.4 0.9987 26.213-Feb-08 2.4 5,900 11,300 638 0.1049 0.042 0.2161 2,150 0.0013 218.2 0.9427 33.127-Mar-08 2.6 5,200 7,530 152 0.0156 0.012 0.0741 2,610 <0.0005 103.5 0.3096 8.0716-Apr-08 2.7 4,200 6,390 279 0.0397 0.01 0.4716 1,090 <0.0005 68.5 0.7485 17.116-May-08 2.6 5,000 7,050 300 0.0437 <0.003 0.0837 1,690 <0.0005 89.9 0.4556 11.416-Jun-08 3.1 4,300 7,770 599 0.23 0.095 0.3102 840 0.0017 56.9 1.664 36.421-Jul-08 2.7 3,800 7,500 565.8 0.213 0.215 0.6350 1,008 0.038 35.7 1.53 34.6

02-Sep-08 2.7 3,900 7,170 507.6 0.219 0.144 0.4420 1,051 <0.01 45.9 1.6 33.515-Sep-08 2.8 3,800 6,930 620.5 0.016 0.158 0.096 0.4170 759 0.023 47.8 1.51 3415-Oct-08 2.6 4,900 8,700 75.59 0.014 0.031 0.015 0.0070 2,688 0.102 107 0.156 5.6717-Nov-08 2.6 4,700 8,040 293.8 0.016 0.061 0.052 0.1750 1,646 0.066 82.3 0.711 16.717-May-10 2.7 5,100 8,910 227 0.005 0.014 0.02 0.0610 2,280 0.003 107 0.529 10.816-Jun-10 2.7 4,700 7,950 442 0.006 0.081 0.046 0.1730 1,580 <0.001 71.7 1.02 23.219-Jul-10 2.6 3,900 7,170 722 <0.003 0.017 0.01 0.0550 834 0.003 54.5 1.62 36.3

16-Aug-10 2.8 2,800 5,520 618 0.009 0.202 0.042 0.4970 475 0.013 32.7 1.4 32.115-Sep-10 2.8 3,300 6,390 N/A 0.019 0.164 0.143 0.6000 N/A 0.022 40.3 1.75 36.418-Oct-10 3 3,600 6,240 712 0.011 0.199 0.089 0.5870 485 0.008 40.8 1.81 37.515-Nov-10 2.8 3,700 6,390 608 0.008 0.168 0.036 0.4300 445 0.003 49.7 1.93 39.616-Dec-10 2.7 4,000 7,320 620 0.018 0.165 0.053 0.5330 748 0.007 46.9 1.99 38.4

For Aquatic Ecosystems 90% Protection Level. Adjusted for Hardness (Based on ~960mg/L as CaCo3, 400mg/L used for calculations of Cd, Cu, Pb, Ni, Zn <6.5/>9.0 0.08 0.042 0.004 0.0162 0.1602 2.5 0.117 0.135



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Figure 1. Annual Rainfall Figures (1975 - 2010)

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APPENDIX 3 REPORTING REQUIREMENTS Report section Requirements / Certification • Certification by authorisation holder that report is true and

accurate

Report identification

• EPA licence number • name and address of licensed site • period covered by report (eg October 2004–October 2005) • date of submission, version number • person responsible for the report

Monitoring objective

• monitoring objective stated in the authorisation • other monitoring requirements (eg assessment criteria) stated in the authorisation

Monitoring plan • statement on whether the approved monitoring plan was adhered to and details on any deviation from the approved monitoring plan or licence conditions and reasons for the deviation

Monitoring results—presentation

• summary of all current results in a graph or table that includes the assessment criteria and highlights results that do not comply with the assessment criteria • analytical methods and the limits of reporting (LoR) for each analyte reported • summary of previous results (sufficient to highlight trends) • calculation of pollutant load discharged into the environment (where required by condition of authorisation)

Monitoring results—quality assurance / quality control (QA/QC) evaluation

• discussion of data completeness • evaluation of QC information from the laboratory and the field data, ie data representativeness, precision and accuracy

Discussion and interpretation of results

• discussion of results where criteria was exceeded • review of trends when compared with previous monitoring data • discussion of results based on monitoring objective(s)

Conclusions and proposed actions

• conclusions on meeting monitoring objective, compliance with assessment criteria and impact on environment • major assumptions or uncertainties • conclusions about effectiveness of the monitoring plan and overview of any proposed changes to monitoring plan (if required) • proposed actions to address non-compliance


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APPENDIX 4 MACRO-INVERTEBRATE REPORT

The Brukunga Acid & Metalliferous Drainage Impact Monitoring Program - Macroinvertebrate Results 2010 1 INTRODUCTION

The Brukunga Acid & Metalliferous Drainage Impact Monitoring Program, initiated in the 1996–1997 financial year, includes monitoring macroinvertebrate and chemical parameters at sites on the Dawesley Creek – Bremer River system. The Australian Water Quality Centre (AWQC) has conducted biological monitoring for Primary Industries & Resources SA subject to an Environment Protection Authority (EPA) licence agreement for management of the disused Brukunga pyrites mine. The principal aim of the monitoring program is to investigate the impact of acid & metalliferous drainage (AMD) on Dawesley Creek including the downstream extent of the impact and subsequent to the construction of a diversion channel around the mine site to investigate the recovery of Dawesley Creek. This report provides a summary of macroinvertebrate results for 2010 and provides comparisons with data from 2001, a year of similar climatic conditions. Rainfall during 2010 was 20% higher than the long-term average for the region, producing high levels of flow in June and September just prior to the sampling event and moderate levels prior to the December sampling. Prior to June relatively little surface water was present. A recommendation from the 2005 survey was for some sites to have riffle habitats sampled, in the wetter months, to determine if the flowing water habitats and associated fauna of Dawesley Creek are recovering. Monitoring of riffles in the study area commenced in 2006. As there is no previous site-specific data for use in determining if these riffles are improving after the creek diversion, the 2006 and subsequent results have been used to represent the baseline condition.

2 METHODS

2.1 Sites

Six macroinvertebrate monitoring sites have been studied for this report (Table 1). The first five sites are in order of increasing distance down Dawesley Creek; Site 1 being an up-stream control and Sites 2-5 being the AMD affected sites. Site 6, at Nairne Creek, was selected as a second control site which flows into Dawesley Creek upstream of the Balyarta Ford site. A stream map (Figure 1) shows all sites that have been sampled during the project, including two sites (Davidson Ck and Bremer River upstream of Callington) that have not been used in this report.


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Table 1. Macroinvertebrate sites monitored quarterly since 1996 and period of entire data record.

Site Name Label Monitoring Duration AWQC Location Code

Dawesley Ck. at Peggy Buxton Rd Site 1 Sept. 1996 – Dec. 2010 4728

Dawesley Ck. D/S Brukunga Site 2 Sept. 1996 – Dec. 2010 3158

Dawesley Ck. at McIntyre Rd Site 3 Sept. 1996 – Dec. 2010 1951

Dawesley Ck. at Balyarta Ford Site 4 Sept. 1996 – Dec. 2010 1822

Dawesley Ck. at Freeway Site 5 Dec. 1996 – Dec. 2010 1952

Nairne Ck. at Djatadapeel Ford Site 6 Sept. 1996 – Dec. 2010 1953

2.2 Macroinvertebrate Sampling and Water Quality Measurements

All sites were visited quarterly during 2010 (in March, June, September and December) and macroinvertebrate sampling and measurement of spot pH, dissolved oxygen (DO) and temperature conducted at each site.

Macroinvertebrate sampling was conducted with sweep nets (250 µm mesh) and conformed to the Australian Rivers Assessment System (AusRivAS) standard protocol, whereby a 10 metre section of stream is sampled (Anon. 2001). Edge habitat was sampled at all sites and is the habitat chosen for comparisons of previous macroinvertebrate assemblages. Riffles were sampled during June from Dawesley Creek downstream of Brukunga Mine and Balyarta, and from Nairne Creek at Djatapeel; and during September from Dawesley Creek downstream of Brukunga Mine and Nairne Creek at Djatapeel. Dawesley Creek water levels were too high during September to collect a riffle at Balyarta. The structure of the stream bed at Peggy Buxton Road below the gauge where a riffle once formed has become slightly deeper and wider distributing flows more evenly past this point and though flowing, no riffle habitat was observed in 2009 and 2010. The spot pH values (reported in the results section), DO and temperature were measured on site with a calibrated multimeter from YSI incorporated (model YSI 556 MPS).


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2.3 Macroinvertebrate Sample Processing

The South Australian AusRivAS laboratory scoring protocol was used to process samples. The protocol involves counting all organisms in a randomly chosen 10% of the sample from a Marchant sub-sampler (Marchant 1989). Sub-sampling continued until a minimum of 200 animals had been identified; for the purposes of obtaining a representative sample. Identification was taken to the lowest practical level using the latest available keys and the AWQC voucher collection. Identification was carried out at family level or lower in all groups except Turbellaria, Nematoda and some Oligochaeta (where they were identified at the levels stated). Most Insecta and Mollusca were taken to species. The Dipteran family’s Ceratopogonidae, Tipulidae, Psychodidae, Stratiomyidae and Simuliidae were taken to species or morpho-species and the Culicidae were taken to genus. The Chironomidae were taken to genus where possible (and in some cases to species) and other Dipteran families were not identified below family.


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Figure 1. Location and site map for the Dawesley Creek System.


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3.1 Interpretation of Macroinvertebrate Data

Macroinvertebrate data were analysed by several techniques including simple indices (taxon richness, abundance); multivariate analyses (MVA), and AusRivAS predictive models.

3.1.1 Species Richness

Species richness, which reflects the number of different types of macroinvertebrates identified in a sample, can be used to estimate the health of a stream, as it reflects the differences between sites, habitats and conditions prior to the date of sampling. A higher number of taxa generally indicate a more natural site with less human-induced stress. It is also accepted that a more diverse community will recover more quickly from both natural and human-induced stresses compared to a community with low diversity. In this report, the term taxon richness is used - as not all the taxa that were counted are species. As detailed in the previous section, some taxa were only identified to family, some to genus and others to species. To ensure the greatest compatibility between data sets generated at different times by different operators, only the highest level taxonomic data were used for Oligochaeta, Collembola and aquatic mites. In order to ensure the most accurate representation of taxon richness, in cases where records of both adult and immature specimens of the same taxon were present in the sample, the data were combined. There are no simple rules for interpreting these complex data sets. Variation - due to factors such as extreme flow events, time of day, chance colonisation by rare taxa, and weather conditions - is always present, as is variation due to water quality, season, habitat variability, ambient temperature and plant productivity. Statements regarding abundance in this report refer to the estimated total abundance within each collection.

3.1.2 Statistical Analyses

MVA are statistical procedures that can detect similarities in biological community data (i.e. the taxa present and their abundance). They are a broad set of objective tools that can be used to seek and reveal structure within complex data sets - avoiding investigator subjectivity. Ordination and classification of macroinvertebrate community data provide an assessment of how similar or dissimilar samples are. Both spatial and temporal patterns can be detected, and such patterns may not be revealed by simple diversity indices and raw taxon richness and abundance figures. When two different MVA methods detect the same pattern, the degree of confidence in the validity of the pattern is increased. This is the approach that was followed, by comparing classification and ordination analyses. MVA were used to conduct a ‘before and after’ comparison of edge samples to investigate for indications of ecological change after several years of operation of the diversion channel. This was done by comparing yearly rainfall from Nairne weather


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station for the years 1996 to 2010 and the pattern and number of dry sites each year. From the six complete years of data available (1997-2002), the 2001 data were selected, as the hydrological conditions then most approximated those in 2010. The statistical package PCORD was used to carry out both classification (Group Average UPGMA) and ordination (NMS non-metric multidimensional scaling). Data were grouped at a range of levels, but were predominantly at the genus and species level. This gave an analysis matrix of 39 samples by 146 taxa. To equalise the relative importance for the analysis of taxa abundance and composition the dataset was transformed. This reduces the weighting any one relatively abundant taxon has on the grouping a site falls within the MVA. The optimum balance between the significance of the two parameters was achieved by performing the 0.3 power transformation. The Bray-Curtis association measure was used on transformed abundance data for both methods. Classification was run with the Groups\Cluster Analysis menu in PCORD. The classification was a hierarchical method run with the group average linkage method. To aid interpretation, seven groups were defined by the software. A five group level was also selected in an attempt to keep analysis standard to previous years however this created one super group containing 27 of the 39 samples. For this reason the seven groupings, initially defined by the software, has been used for analysis in this report. Ordination was run with the Ordination\NMS menu in PCORD. A three-dimensional solution was calculated using a maximum of 400 iterations, a random start and a stability criterion of 0.00001. The resulting stress value was 15.2 and the solution was stable after approximately 40 iterations. The stability criterion was chosen at the very low level of 0.00001 to guarantee the reliability of the ordination solution. The MVA ordination can be set to run an indefinite number of solutions until it finds the solution with the lowest stress (stress between 12 and 19 are considered acceptable) and meeting the stability criterion. In the case of the chosen 400 iterations, if the ordination had not found a solution after 400 attempts which met the stability criterion and with a stress less than 19, it would have reported that no solution had been found. In this case the ordination result is very reliable with the solution resolved with the set stability criterion after 40 attempts in a 3 dimensional plane with a stress of 15.2. If a stress of 20 or over is recorded it means the ordination result could have been arrived at by chance rather that consistent patterns in the data and the program states the results are unreliable.

3.1.3 AusRivAS Models

AusRivAs was the first national biological assessment of river health to be conducted on a continental scale. The condition of a river site is determined by comparing family-level macroinvertebrate data to that of a local reference site which is considered to be in a relatively undisturbed or unimpacted state. The model then produces a rating that is a guide to the level of impact influencing the health of site. Additionally the probability of each family occurring in any one sample is calculated. These outputs are useful to determine the effectiveness of the rehabilitation of the creek by comparing the fauna to reference sites.


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The AusRivAS models function by using chemical and physical variables to classify a sample and then predict the families that should be present in that sample if it were from a reference site based on the classification group probabilities. This predicted (or “Expected”) number of families is then compared with the number of families collected (or “Observed”) in the sample. The comparison is in the form of a ratio of the Observed: Expected number of families – or OE in AusRivAS. The models make frequent use of a 50% probability of taxon occurrence at a site. This is because those taxa with a > 50% chance of occurring are considered the most useful for detecting a real decline in the number of taxa (Coysh et al. 2000). The AusRivAS output used in this report is the OE50 which is the observed: expected ratio for families predicted at greater than 50% probability for a sample. The OE50 ratio can be simplified to a band. Band ratings are X (higher than expected observed number of taxa), A (equivalent to reference), B (reduced number of families and therefore significantly impaired), C (severely impaired) and D (extremely impaired). The probabilities which determine the boundaries between bands may be different for each model season, as they are based on percentiles. Six seasonal models used for this report and included the autumn edge and riffle model, spring edge and riffle model and the combined-season edge and riffle models. Sample data from June was run in the autumn edge model and the sample data from September and December was run in the spring edge model. The combined-season edge model data was produced by pooling the invertebrate families present in the June and September samples. The riffle samples from June were tested in the autumn riffle model and those from September were tested in the spring riffle model. The combined-season riffle model data was produced by pooling the invertebrate families present in the June and September samples.

3.1.4 Missing Taxa

A feature of the AusRivAS model is the Predicted Taxa output, in which the model generates a probability value (ranging between 0 and 1) of each family being present in a sample. This is not based on detailed information of the biology of the animals but on statistical relationships between the physical and chemical characteristics of streams and the distribution patterns of families across reference sites. The larger the percentage that a taxa is predicted at a site the more weighting it carries towards the Observed versus Predicted taxa output (OE50), which is the final probability determining the AusRivAS model output rating. Taxa which are considered to be missing from samples are those which are predicted to be at a site with a probability greater than 0.5, but were not collected. The missing animals of the most concern are those with the highest probability values, particularly if they are absent from a number of samples from a single site or catchment. It was recommended in the 2005 report that taxa highly predicted by the AusRivAS autumn and spring riffle models be identified and their presence at sites monitored into the future to see if the riffles are approaching reference site condition and thus improving in ecological health. As 2010 is now the fifth year riffles have been sampled, there is data from 2006, 2007, 2008 and 2009 with which to draw comparisons.


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4 RESULTS

4.1 Macroinvertebrate Richness

4.1.1 2010 Surveys

The primary results consist of a list of taxa recorded at each site and the abundance estimate of each taxon (Appendix 1). Below are graphical representations of this raw data per sampling event for 2010. Field pH has been added to indicate the major differences in water chemistry at different sites and times. It is referred to as spot pH. Even though a clear correlation between taxa and pH is evident, causality is not implied. There are many differences in the chemistry of low pH AMD and higher pH (neutral or alkaline) streams. Reduced diversity is not simply attributable to increased acidity.

4.1.1.1 March 2010

In previous surveys, it has been common for many Dawesley Creek sites to be dry in March. In 2010, surface water existed at the Brukunga Mine site where a total of 24 taxa were collected (Figure 2).

Figure 2. March 2010 taxon richness and pH - edge habitat.


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4.1.1.2 June 2010

All sites had flowing habitat in June 2010 with the exception of the Freeway which was dry. All sites had a spot pH value close to neutral. Peggy Buxton possessed the highest taxon richness count for the edge habitats with 28 taxa recorded. Nairne Ck had the second highest number of taxa with 27 recorded. Taxa richness was lower in comparison to the reference sites at Brukunga Mine, McIntyre Rd and Balyarta with 16, 16, and 14 taxa recorded respectively (Figure 3). Riffle habitats present in June were at Brukunga Mine, Balyarta and Nairne Ck (Figure 4) where taxa richness was lowest at Brukunga Mine and Balyarta with 8 and 9 taxa recorded respectively and higher at and Nairne Ck with 16 taxa recorded.

Figure 3. June 2010 taxon richness and pH - edge habitat.


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Figure 4. June 2010 taxon richness and pH - riffle habitat.

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4.1.1.3 September 2010

Flowing water was present at all sites in September and 12 days prior to sampling Dawesley Creek was in flood. Spot values of pH were slightly below neutral at Peggy Buxton, Brukunga Mine, McIntyre Rd and Nairne Ck with values of 6.8, 6.45, 4.93 and 6.59 respectively (Figure 5). Balyarta and the Freeway had values just above pH 7.21 (Figure 5). In edge samples, macroinvertebrate richness was highest at the Brukunga Mine site with 29 taxa, followed by McIntyre Rd with 27 taxa (Figure 5). In a continuing trend Nairne Ck did not have the highest taxa richness in September for edge habitats, as it had prior to 2007. Riffle habitats occurred at Brukunga Mine and Nairne Ck, with Brukunga Mine showing the highest taxon richness value of 7 different taxa (Figure 6).

Figure 5. September 2010 taxon richness and pH - edge habitat.


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Figure 6. September 2010 taxon richness and pH - riffle habitat.


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4.1.1.4 December 2010

All sites contained surface water in December. Flowing water was observed at all sites with surface water. The spot pH values ranged from 6.3 at Brukunga Mine to 7.4 at Balyarta (Figure 7). Peggy Buxton had the highest taxa richness with 47 taxa recorded followed by Brukunga Mine with 38 taxa recorded (Figure 7). No riffles were sampled in December.

Figure 7. December 2010 taxon richness and pH – edge habitat.

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4.1.2 Mean taxon richness 1996-2010

A comparison of the macroinvertebrate taxonomic richness prior to and since the operation of the diversion scheme is presented in Figure 8. Since March 2003, all sites on Dawesley Creek that have been exposed to AMD have on average supported more macroinvertebrate taxa (Figure 8). This trend of improved ecological health is most marked at Brukunga Mine and McIntyre Road (Figure 8) and, although the improvements are just shy of being statistically significant, additional data collection may further confirm this trend. The reference site at Nairne Ck is the only site where taxon richness has been shown to decrease during the period between 2003 and 2010; although not statistically significant (Figure 8).

Figure 8. Mean taxon richness at six sites: 1996 – 2002 and 2003 – 2010. Error bars show two standard deviations.

4.2 Temporal Changes at Each Site

At each of the six sites, edge-habitat sample data from March 2000 to December 2010 has been presented (Figures 9, 11, 13, 14, 16 & 17). This allows the 2010 data to be compared with the findings of earlier years. Due to difficulties fitting all collected data onto the graphs, data from 1996 to 1999 have been removed for the purposes of this report, but can be reviewed in appendix 2. The riffle sample data presented is from 2006 to 2010 (Figures 10, 12, 15, & 18) as only four years of data collection has occurred. In all the figures that follow, taxonomic richness for the different months is: yellow for March, blue for June, green for September and brown for December.


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4.2.1 Peggy Buxton Road

Flow levels were variable, and often ceased in autumn, but generally the pools remained and a macroinvertebrate community was always present. This trend was broken in March 2008 and 2009 when the site was observed to be dry. Spot pH fluctuated over the years from 6 to 8 until December 2006 when it peaked with a value approaching 9. In edge samples, taxon richness peaked in 2002 when 42 different taxa were recorded in December. December 2010 proved to be the highest month of diverse taxa with 47 present. The lowest numbers of edge taxa were recorded in September 2003 and September 2006 when 13 and 14 taxa were recorded respectively (Figure 9). Riffle habitat was present in June and September in 2006 and 2007; however none was present in 2008 and 2009 (Figure 10). The highest riffle taxon richness was recorded in 2007 with 24 different taxa having been observed. The pattern of taxon richness in 2008 and 2009 appears similar even though the rainfall differed greatly in these two years (Figure 9).

Figure 9. Taxon richness and pH from edge habitat at Peggy Buxton Road from

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Figure 10. Taxon richness and pH from riffle habitat at Peggy Buxton Road from 2006 to 2010.


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4.2.2 Brukunga Mine

The first recorded spot pH above 7 since the diversion became operational was in December 2003. Measurements in 2004 followed this trend, showing peaks in pH for March and June since 1996 (Figure 11). Similar conditions seem to have continued until 2008 with pH fluctuating between 4.3 and 7.5 units. The March 2010 spot pH of 4.26 is the lowest recorded post diversion. During 2008 and 2009 spot pH values have not dropped below 5.68. It is obvious since the diversion in 2003 that pH is now more variable with neutral or near neutral conditions being present on most visits. The site has been dry on four occasions, in December 2006 and 2007 and in March 2008 and 2009. Maximum taxon richness from edge samples was recorded in December 2008, 2009 and 2010 with 42, 33 and 38 different taxa recorded respectively. Riffle habitats were present in June and September for the last five years. Taxon richness peaked in September in 2008 with 15 different taxa recorded and reached its lowest in September 2009 with two different taxa recorded (Figure 12). In September 2010 the riffle-habitat taxon richness is back on the rise with 7 different taxa present.

Figure 11. Taxon richness and pH from edge habitat downstream of Brukunga Mine from 2000 to 2010.


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Figure 12. Taxon richness and pH from riffle habitat downstream of Brukunga Mine from 2006 to 2010.


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4.2.3 Upstream McIntyre Road

Post diversion, spot pH values tend to vary between 7.0 and 8.0 except in June of each year when values dropped to between 4.67 and 6.5 and September of 2010 with 4.9. There was an exception however in 2007 (Figure 13) when pH took a sharp downward turn from September to December. The site has had no surface water in March since 2005. There appears to be a trend for highest taxon richness in December 2006, December 2007, December 2008 and December 2009 where the highest recorded taxon richness at this site was 31 different taxa. Breaking this trend in 2010, September was the month with the highest recorded taxa. No riffle has been observed upstream of McIntyre Rd during the last four years.

Figure 13. Dawesley Creek: Taxon richness and pH from edge habitat at McIntyre Road from 2000 to 2010.


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4.2.4 Balyarta

The section of Dawesley Creek downstream of its confluence with Nairne Creek is usually dry in late summer and early autumn. The 1996/97 (no longer on graph) and 2004/05 summers were wetter, and drying of the stream was not observed (Figure 14). Spot pH has not dropped below 6 units at Balyarta since September 2004, with September of most years since then recording the highest spot pH values, with 2005 and 2009 recording over 8.3 (Figure 14). During 2009, taxon richness in edge samples showed highest richness in December, which matches the pattern seen at Balyarta in all years (except 2001) when there was surface water present in December (Figure 14). During 2010 the pH remained fairly constant at around 7.4 with the exception of March when the site was dry. September 2010 proved to have the highest taxon richness with 26 taxa present. The riffle habitat has been surveyed in June and September for the last four years with taxon richness peaking in June 2007 with 25 different taxa (Figure 15). June 2010, was the only month a riffle was present at Balyarta with a total of 9 different taxa present.

Figure 14. Taxon richness and pH from edge habitat at Balyarta from 2000 to 2010.


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Figure 15. Dawesley Creek: Taxon richness and pH from riffle habitat at Balyarta from 2000 to 2010.


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4.2.5 Freeway

The Freeway is an intermittently flowing site and taxa richness has been variable over the years of monitoring (Figure 16). During 2004-2009, the pH was alkaline to neutral (ranging from 6.9 to 8.1), suggesting the AMD influence was subdued or absent at these times. The highest values of taxa richness were recorded in December of 2004 and 2005. The last four years show a pattern of the creek being dry in March and December with taxa richness being higher in September. This trend was broken in 2010 where the site was dry in March and June. September presented 20 different taxa along with 22 taxa in December. No riffle habitat was observed at this site.

Figure 16. Taxon richness and pH from edge habitat at the Freeway from 2000 to 2010.


74

4.2.6 Nairne Creek

From 1996 to 2003 this local control site was slightly eutrophic but had a taxon richness and pH that was comparable to other Mount Lofty Ranges streams with reasonable water quality (Figure 17). It reflected the condition expected to prevail in Dawesley Creek if AMD and treated wastewater from the Bird-in-Hand WWTP were not present, with highest taxon richness in winter and spring. In December 2007 the site was dry and remained so in March 2008 and this pattern was repeated in December 2008 and March 2009. In contrast, during 2009, surface water persisted through to December - where the highest taxon richness of 26 was recorded for that year (Figure 17). In 2010 the site was dry only in March and for the rest of the year remained flowing. June had the highest taxon richness of 25 taxa. Since the beginning of the project, spot pH has remained relatively constant ranging from 6.7 to 8.5, with the exception of June 2004 when the pH dipped to 5.11. Since that decrease the pH has somewhat stabilised to around neutral with the occasional drop to 6.5. Apart from the dry periods, in general, pH and taxa diversity remained relatively consistent at this site until 2007 when the Creek was altered by a raised road crossing. Riffle habitat has been present in June for the last five years and September for the three years prior to 2009 with taxon richness peaking in September 2007 recording 34 different taxa (Figure 18). Riffle habitat taxon richness was noticeably lower in June and September 2008, June 2009 and then significantly lower in September 2010 with only 6 different taxa present.

Figure 17. Taxon richness and pH from edge habitat at Nairne Creek from 2000 to 2010.


75

Figure 18. Taxon richness and pH from riffle habitat at Nairne Creek from 2006 to 2010.

4.3 Comparison of taxon richness and pH over all sites containing riffle habitat from 2006 to 2010

Nairne Creek recorded the greatest decrease in riffle health, whilst Brukunga Mine remains fairly steady, although relatively low and Balyarta has had a slight decrease from 2006 to 2008 where health was greater (Figure 19). A riffle habitat has not been recorded at Peggy Buxton over the last three years. The lowest spot pH value over the three years occurred at Brukunga Mine in June 2007 with a value of 5.3. The highest spot pH occurred at Balyarta in September 2009 with a value of 8.3. Spot pH values tended to vary most greatly at Brukunga Mine and Nairne Creek (Figure 19).


76

Figure 19. A comparison of taxon richness and pH from riffle habitat at each site from 2006 to 2010.

4.4 AusRivAS Outputs

Results from the AusRivAS models for the 2010 data are shown in Table 2. Brukunga Mine was the only wet site in March 2010 and hence there are no AusRivAS results for the other sites for this sampling event. The edge model rated Peggy Buxton Road to be an ‘A’ (same as local reference site) for June, September and December. No riffles were observed at Peggy Buxton Road. The Brukunga Mine edge habitat rated an ‘A’ in March, September and December and a ‘B’ (slight impairment to ecological health) in June. The two riffles present at Brukunga Mine in June and September received a ‘C’ (significant impairment to ecological health) rating. Edge samples collected at McIntyre Rd received a ‘B’ rating for June and December and rated an ‘A’ in September. No riffles were sampled in Dawesley Creek upstream of McIntyre Rd throughout the survey. Balyarta received a ‘B’ rating from the edge model in June, September and December. Riffle habitat sampled at Balyarta in June received a ‘C’ rating. The Freeway edge samples received a ‘B’ rating in September and December; no surface water was present in March and June. The edge model rated Nairne Creek an ‘A’ in June and December and a ‘B’ in September. The two riffles present at Nairne Creek received a ‘B’ rating in June and a ‘D’ (severe impairment to ecological health) rating in September. The combined season edge model rated the Peggy Buxton and McIntyre Road sites as an ‘A’. Ratings of ‘B’ were allocated to Brukunga Mine, Balyarta and Nairne Creek. The combined-season riffle model rated the Brukunga Mine a ‘C” and Nairne Creek a ‘B’ (Table 2).

0

1

2

3

4

5

6

7

8

9

0

5

10

15

20

25

30

35

40

45

Jun-

06

Sep

-06

Jun-

07

Sep

-07

Jun-

06

Sep

-06

Jun-

07

Sep

-07

Jun-

08

Sep

-08

Jun-

09

Sep

-09

Jun-

10

Sep

-10

Jun-

06

Sep

-06

Jun-

07

Sep

-07

Jun-

08

Sep

-08

Jun-

09

Sep

-09

Jun-

10

Jun-

06

Sep

-06

Jun-

07

Sep

-07

Jun-

08

Sep

-08

Jun-

09

Jun-

10

Sep

-10

pH

TAXO

N RI

CHNE

SS

DATE

TAXON RICHNESS

pH

Peggy Buxton

Brukunga Mine

Balyarta Nairne


77

Table 2. AusRivAS results for sites sampled in 2010. A equal to reference sites, B slight impairment to ecological health, C significant impairment to ecological health, X above reference condition and D extreme impairment to ecological health.

4.5 Highly Predicted and Missing Taxa

4.5.1 Riffle Habitats

Table 3 outlines the taxa predicted to be in riffle habitat at the three sites that had riffles sampled in 2010. The light green in Table 3 represents collected taxa with a probability of 0.5 or above, and the dark green represents uncollected taxa that were predicted at a high probability (0.7 or above) at a site, during the autumn and spring seasons. Table 4 shows comparisons between years of high probability taxa not collected and taxa with 0.5 or above probability that were collected. There are some families of macroinvertebrates marked blue in Table 3 that are predicted at a high probability and missing at most AMD affected sites and now Nairne Creek also. The return of these macroinvertebrates should be monitored in future surveys to determine if recovery of riffle habitats is occurring. By observing the figures in Table 3 it is apparent that riffle habitat at Brukunga Mine, Balyarta and Nairne Creek received significantly impaired ecological health ratings due to the taxa predicted but not collected (‘missing taxa’) throughout the surveys. This amounted to 17, 14 and 17 highly predicted ‘missing taxa’ (≥70% likelihood of being collected) at each site respectively over the annual survey; and compares to 13, 9 and 4 highly predicted ‘missing taxa’ from the same sites in 2007 (Table 4). The number of taxa that had a high probability of being collected and were present at Brukunga Mine, Balyarta and Nairne Creek was 12, 14 and 11 taxa respectively. These figures are lower for Nairne Creek than the previous last two years, and then become especially pronounced at Nairne Creek if compared to 2006 and 2007 figures where the number of highly predicted taxa that were collected was 29 and 24 taxa respectively. The Brukunga Mine site has had an increase in predicted taxa collected having only 4 in 2009 to an increase of 12 in 2010. No riffle habitat was observed at Peggy Buxton Road from 2008 to 2010.

OE50 Band OE50 Band OE50 Band OE50 Band OE50 Band OE50 Band

March edge 0.84 Ariffle

June edge 0.85 A 0.76 B 0.76 B 0.68 B 0.82 Ariffle 0.43 C 0.42 C 0.51 B

Sept edge 0.84 A 0.96 A 0.9 A 0.7 B 0.61 B 0.65 Briffle 0.44 C 0.15 D

Dec edge 1.15 A 1.05 A 0.74 B 0.75 B 0.65 B 1.05 Ariffle

Combined edge 0.84 A 0.8 B 0.84 A 0.6 B 0.77 BJun/Sept riffle 0.45 C 0.49 B

2010Peggy Buxton Brukunga Mine McIntyre Rd Balyarta Nairne Creek

4728 3158 1951 1822 1952 1953Freeway

DRY DRY DRY DRY DRYRiffle not present

Riffle not present Riffle not present Riffle not present

Riffle not present Riffle not present

Riffle not present Riffle not present Riffle not present

DRY

Riffle not present

Riffle not presentRiffle not presentRiffle not present

Riffle not present Riffle not present Riffle not presentRiffle not presentDry in Autumn


78

Table 3. Macroinvertebrate families predicted by the autumn and spring riffle AusRivAS model for 2010 data. >> collected at the site, 0.7 to1.0 predicted at site >70 % and not collected, no colour predicted at a site at between 50 and 69 % and not collected. Note that taxa predicted between 50 and 69% which were not recorded from any site were deleted from the comparison. Cells coloured blue represent macroinvertebrates to look for in future surveys as evidence for improvement in ecological health.

Family Common name Balyarta Nairne Mine

Autumn Riffle

Nematoda Round worm »0.88 »0.88 0.84

Hydrobiidae Freshwater snail 0.91 0.93 0.81

Oligochaeta Freshwater worm »0.98 »0.98 0.96

Acarina Water mite »0.88 0.87 0.92

Ceinidae Scuds 0.81 0.82 0.73

Collembola Springtails »0.59 »0.60 »0.56

Tipulidae Crane fly 0.46 0.44 »0.59

Ceratopogonidae Biting midge larvae »0.82 0.82 0.84

Simuliidae Black fly larvae 0.95 »0.95 0.94

Empididae Dance fly larvae 0.59 »0.63 0.33

Tanypodinae Non-biting midge larvae 0.87 0.88 0.82

Orthocladiinae Non-biting midge larvae »0.98 »0.99 »0.91

Chironominae Non-biting midge larvae »0.98 »0.98 »0.98

Gripopterygidae Stonefly 0.86 »0.91 »0.66

Hydrobiosidae Clawed daddis fly 0.79 0.87 0.36

Hydroptilidae Micro caddis fly 0.76 0.79 0.57

Leptoceridae Stick caddis fly 0.55 »0.56 0.45

Spring Riffle

Nematoda Round worm

0.97 0.97

Hydrobiidae Freshwater snail

0.91 0.88

Oligochaeta Freshwater worm

»1.00 »1.00

Acarina Water mite

0.97 »0.95

Ceinidae Scuds

0.85 »0.92

Collembola Springtails

»0.48 »0.52

Scirtidae Marsh beetle

0.62 »0.57

Ceratopogonidae Biting midge larvae

0.88 0.86

Simuliidae Black fly larvae

0.96 0.96

Tanypodinae Non-biting midge larvae

0.92 0.91

Orthocladiinae Non-biting midge larvae

»1.00 1

Chironominae Non-biting midge larvae

0.98 »0.99

Leptophlebiidae Mayfly

0.79 0.72

Gripopterygidae Stonefly

0.55 »0.46

Hydrobiosidae Clawed caddis fly

0.81 0.72

Hydroptilidae Micro caddis fly

0.64 0.7


79

Table 4. A comparison of macroinvertebrate families predicted (at equal or greater than 70%) but not

collected, and families predicted (at equal or greater than 50%) and collected at four sites containing riffle habitat from 2006-2010. Balyarta has had its figure doubled as only one season present.

Balyarta Nairne Mine Peggy Buxton

Taxa highly predicted but not 2006 collected 9 3 17 11

(OE50 of 0.7-1.0) 2007 9 4 13 5

2008 12 16 9 NO FLOW

2009 17 14 19 NO FLOW

2010 14 17 17 NO RIFFLE

Taxa predicted & collected 2006 18 29 8 16

(OE50 of 0.5-1.0) 2007 18 24 12 20

2008 14 13 11 NO FLOW

2009 10 14 4 NO FLOW

2010 14 11 12 NO RIFFLE

4.5.2 Edge Habitats

In previous reports it has been recommended that the highly predicted taxa for edges be identified to determine if there are certain groups of macroinvertebrates that are missing in edge samples and which animals to look for into the future. The colour code and rationale of interpretation is the same as that just outlined for riffles and the AusRivAS predicted values for the December 2010 survey only are outlined in Table 5. Peggy Buxton, Brukunga Mine and Nairne Creek received ‘A’ band ratings in December 2010 with a high percentage of taxa predicted at > 50% collected at the time of sampling (Table 5). McIntyre Road, Balyarta and the Freeway received ‘B’ band ratings with a lower percentage of taxa predicted at > 50% collected at the time of sampling. There were some taxa highlighted in blue in Table 5 that were highly predicted and missing from many sites, they were a freshwater snail, scuds and biting midge larvae. The return of these macroinvertebrates should be monitored in future surveys to determine if further recovery of edge habitats is occurring. Water mites and stick caddis flies that were absent from most sites in December 2009 are now present at most sites in December 2010.


80

Table 5. Macroinvertebrate families predicted by the spring edge AusRivAS model for December 2010 data. >> collected at the site, 0.7 to1.0 predicted at site >70 % and not collected, no colour predicted at a site at between 50 and 69 % and not collected. Note that taxa predicted between 50 and 69% which were not recorded from any site were deleted from the comparison. Cells coloured blue represent macroinvertebrates to look for in future surveys as evidence for improvement in ecological health.

Family Common Name Peg Bux Mine McIntyre Balyarta Freeway Nairne

Nematoda Round Worm »0.79 »0.80 0.79 »0.80 0.79 »0.80

Hydrobiidae Freshwater snail 0.75 0.7 0.75 0.78 0.75 0.72

Physidae Freshwater snail »0.54 »0.51 0.54 »0.51 »0.55 »0.52

Oligochaeta Freshwater worm »0.96 »0.96 0.96 »0.96 »0.96 »0.96

Acarina Water mite »0.86 »0.86 »0.85 »0.85 0.85 »0.88

Ceinidae Scuds »0.91 0.92 0.9 »0.90 0.91 »0.92

Collembola Springtail 0.48 »0.47 »0.49 »0.50 »0.49 0.45

Dytiscidae Predacious Diving Beetle »0.78 »0.82 »0.77 0.72 »0.78 »0.83

Ceratopogonidae

Biting midge larvae »0.71 »0.76 0.71 0.7 0.71 0.75

Tanypodinae Non-biting midge larvae »0.91 »0.87 »0.91 »0.94 »0.91 »0.88

Orthocladiinae Non-biting midge larvae »0.91 »0.86 »0.91 »0.95 »0.91 »0.86

Chironominae Non-biting midge larvae »1.00 »1.00 »1.00 »1.00 »1.00 »1.00

Veliidae Small water strider »0.53 »0.43 »0.52 0.59 0.52 »0.47

Corixidae Water boatman »0.79 »0.76 »0.81 0.8 0.81 »0.74

Notonectidae Backswimmer »0.56 0.57 »0.57 »0.52 »0.58 »0.55

Leptoceridae Stick caddis fly »0.67 »0.52 »0.68 »0.78 »0.67 »0.55

AusRivAs predictors

Number of taxa expected > 0.5 probability 12.22 11.42 12.23 14.59 12.24 11.47

Number of taxa collected > 0.5 probability 14 12 9 11 8 12

OE 50 AusRivAS % 1.15 1.05 0.74 0.75 0.65 1.05

Band A A B B B A


81

4.6 Multivariate Analysis Results

4.6.1 Cluster analysis 2001, 2009

Results of the cluster analysis are presented in a dendrogram (Figure 20) which shows the grouping of samples with similar macroinvertebrate assemblages. For the purpose of interpretation, seven groups were identified from the dendrogram. These groups are labelled 1-7 in Figure 20 and the group membership is listed in Table 6. Table 7 states the relevant group statistics for taxa richness and abundance. Group 1 consisted of one sample from Brukunga Mine post-diversion that had high taxa richness and low abundance (Table 6 and 7). Group 2 consisted of five samples from Brukunga Mine and McIntyre Rd in 2001 (when exposed to AMD) and one from June 2010 which had low taxa richness and medium abundance (Tables 6 and 7). Group 3 comprised 33% of samples and included local reference sites and improved AMD exposed sites from December 2010 with high taxa richness and moderate abundance (Table 6 and 7). Group 4 comprised 28% of samples and included sites previously exposed to AMD and most 2010 September samples which have experienced high flows that were characterised by having moderate taxa richness and low abundance (Table 6 and 7). Group 5 consisted of three samples from local reference sites characterised by having moderate taxa richness and low abundance (Table 6 and 7). Group 6 consisted of three samples from AMD affected sites experiencing near neutral pH (6.26 to 6.62) characterised by having moderate taxa richness and low abundance (Table 6 and 7). Group 7 consisted of 2 samples from AMD sites post-diversion characterised by having low taxa richness and low abundance (Table 6 and 7).


82

Table 6. Group membership of cluster analysis.

Group

Designation Sites Years Months

1 High acidity refuge pool High taxa richness and low abundance

Brukunga

2010

March

2 Sites receiving AMD in 2001 Sample with low taxa richness and very high abundance

Brukunga McIntyre Road

Both 2001

March, June and December(2001); June (2010) June and December

3 Local reference sites Some improved AMD- exposed sites, approximating reference sites High taxa richness and moderate abundance

Nairne Creek

Peggy Buxton

Brukunga

Balyarta

Freeway

Both

Both

2010

2010

2010

June, September and December (2001); June and December (2010).

June and December (2001); June, September and December (2010).

December

December

December

4 Sites receiving AMD in 2001 Sites influenced by recent high flows Moderate taxa richness and low abundance

Brukunga McIntyre Road Balyarta Freeway Nairne Creek

Both Both Both Both 2010

September

September

September and June (2001)

September and June (2001)

September

5 Local reference sites Samples with moderate taxa richness and low abundance

Peggy Buxton Nairne Creek

2001 2001

March and September March

6 Recovering AMD affected sites Moderate taxa richness and low abundance

McIntyre Road Balyarta Freeway

2010 2001 2001

December December December

7 Still impacted previously exposed AMD sites Low taxa richness and abundance

McIntyre Road Balyarta

2010 2010

June June


83

Table 7. Macroinvertebrate community statistics of cluster analysis groups.

Group Number of

Samples

Taxon Richness

Abundance

Min. Max. Mean Min. Max. Mean

1 1 24 24 24 801 801 801

2 6 5 16 12 852 46240 10113

3 13 22 47 31 348 11311 3987

4 11 20 32 25 116 1798 730

5 3 18 28 22 364 2484 1535

6 3 23 28 25 727 3054 1742

7 2 14 16 15 2020 3621 2821


Australian Water Quality Centre 84

Figure 20. Dendrogram of 2001 and 2010 edge samples. (First two letters designate site. PB = Peggy Buxton Road, BM = D/S Brukunga, MR = McIntyre Road, BA = Balyarta, FW = Freeway, NC = Nairne Creek. Third letter designates month, M = March, J = June, S = September and D = December. Digits indicate year of collection). Interpretation of Groups 1-7 is provided in Table 5.

Information Remaining (%)100 75 50 25 0

BMM10BMJ10MRJ01BMM01BMJ01BMD01MRD01PBJ10PBJ01PBS10PBD10PBD01NCJ01NCD01NCS01NCJ10NCD10BAD10FWD10BMD10BMS10MRS10NCS10BAS10FWS10MRS01BAS01FWS01BAJ01FWJ01BMS01PBM01NCM01PBS01MRD10BAD01FWD01MRJ10BAJ10


85

4.6.2 Ordination 2001 and 2010

The NMS ordination in 3 dimensions produced similar groupings to the cluster analysis. Though clearly defined, Groups 3 and 4 shared boundaries (Figure 21) emphasising the similarity in taxa composition between samples from the reference sites and some September 2010 samples. The AMD impacted samples from Brukunga Mine and McIntyre Rd formed Group 2 to the upper middle of the ordination and had close affiliation with two Group 4 samples from AMD impacted sites in June of 2001 and the one Group 1 sample from Brukunga Mine in 2010 when low pH was recorded (Figure 21). Group 5 samples are from reference sites and are separated from Group 3 reference sites by having a dissimilar taxa assemblage and occupy the lower left hand of the ordination. AMD impacted samples at the Freeway and Balyarta from December 2001 and McIntyre Rd 2010 form Group 6 and occupy the middle right side of the ordination, they share many taxa in common, but differ from other groups. The taxonomically diverse samples from local reference sites and improved December 2010 AMD exposed sites approximating reference condition occupy the lower middle to left side of the ordination plot. They are separated by the greatest difference on the Y axis from the species-poor but medium to high abundance 2001 samples from Brukunga Mine, McIntyre Road and Balyarta (Groups 2 and 7) (Figure 21). The distribution of samples in the direction of the X axis appears to be determined by the type and number of different taxa and on the Y axis by the number of individuals. Some June 2010 (Group 7) sites are associated with some of the impacted AMD sites from June and March in 2001 (Figure 21). The ordination plot puts previous AMD impacted December 2010 sites with local reference sites from 2001 and 2010 suggesting that the macroinvertebrate species at Brukunga Mine, Balyarta and the Freeway have changed and become more similar to that at local reference sites that have not been exposed to AMD. Group 4 sites comprise mainly September samples from 2001 and 2010 suggesting flow patterns at the time may be influencing the taxa composition and number.


86

Figure 21. SSH Ordination of 2001 and 2010 edge samples. Group numbers are those from the cluster analysis.

Group

1

2

3

4

5

6

7


87

5 DISCUSSION AND CONCLUSIONS

During this monitoring program, the water in Dawesley Creek has altered from an acidic state that was unsuitable as habitat for most macroinvertebrates to an environment that more frequently has a neutral pH and is more favourable to the colonisation of macroinvertebrates and which, at times, resembles reference condition as predicted by AusRivAS models. The construction of the diversion around the mine site in 2003 was intended to isolate the mine and prevent much of the contamination (Randall and Cox, 2003). The indications from the 2010 monitoring is that (given favourable hydrological conditions and connected baseflow) Dawesley Creek sites are improving compared to the conditions prior to the diversion; this was especially evident in December at Brukunga Mine, Balyarta and the Freeway. Deterioration in stream health is evident at the reference site at Nairne Creek, likely due predominately to stream alteration as a result of road construction works at the site. Climatic conditions from November 2009 to March 2010 were dry and hot leaving all but the Brukunga Mine site dry in March 2010. The Brukunga Mine site contained pooled water behind the gauge which had a pH of 4.26. The La Nina event which followed in the mid to later half of 2010 has seen above average rainfall and a few high rainfall events in the Dawesley Creek catchment, two of which occurred just prior to the June and September sampling. Although the June rainfall event was significantly high, the catchment at the time was not fully wetted up and flow to Dawesley Creek in June caused the creek to rise 7cm above base flow for a short time, which should not have significantly influenced the macroinvertebrate assemblage present. The rainfall events before the September sampling, however, had creek height at the Brukunga Mine gauge rise on three occasions- it peaked on the 26th of August, 3rd and 14th of September at 40cm, 97cm and 40cm respectively. A similar pattern of creek height at the Brukunga mine gauge in September 2001 saw levels rise on the 7th

of September to 50cm above gauge height, five days prior to the September 2001 sampling. These relatively high flow events, coupled with reduced temperatures, impact upon the establishment of a healthy macroinvertebrate community. In addition to unusual weather patterns prior to the September sampling, it is also important to note that the AusRivAS manual does not recognise September as part of the spring season model (Anon. 2001), and that spring sampling should be undertaken in the months of October to December somewhere between 2 to 4 weeks after the cessation of high flows (Coysh et al. 2000). Hence the AusRivAS data for September should be interpreted with some caution.

During March 2010 there was water at the Brukunga Mine site only; its macroinvertebrate assemblage was rated equal to reference with many different types of macroinvertebrates seeking refuge in one of the few areas of water in Dawesley Creek. They primarily consisted of adult Coleoptera (three families), Hemiptera (three families), and Diptera larvae (six families). Not surprisingly with the low pH, soft bodied macroinvertebrates, crustaceans and molluscs were absent from the site, with the exception of the first recorded yabby from an AMD impacted site.


88

The late onset of flows in Dawesley Creek at the beginning of 2010 coupled with the past impact of AMD may be contributing to the slight impairment to health ratings recorded at Brukunga Mine, McIntyre Road and Balyarta in June 2010. The two reference sites also experienced late onset of flows and recorded equal to reference health ratings. The September survey has Brukunga Mine and McIntyre Road rated at equal to reference; however it is considered likely that this rating is biased, as the survey was undertaken post high flows. These flows distribute/relocate macroinvertebrates from their refuges and dilute them throughout the catchment. This dilution requires a greater proportion of the collected sample be examined microscopically to find the 200 animals required to satisfy the AusRivAS model. With the increase in the percent of the sample examined there is increased probability of discovering different small taxa, inflating the taxanomic richness of the site and also increasing the number of families discovered which is used in an AusRivAS assessment. Therefore it is difficult to determine any immediate impact AMD has on Dawesley Creek from the September macroinvertebrate results. As in 2009, when discussing the macroinvertebrate results for 2010, the December 2010 survey best illustrates the health status of the catchment. The June and September results reflect the influence of hydrology on the system and its impact upon macroinvertebrate communities while discussion around the June and September results is of lesser value in the context of the AMD study.

Figure 22. Water Height Brukunga Mine Gauge station May-November 2010. (Data present in website up to 27 November 2010 only, as of 23/3/11) DWLBC Surface Water Archive- http://e-nrims.dwlbc.sa.gov.au/SiteInfo/ViewSiteData.aspx?id=A4260659_WLREC

0.8

0.85

0.9

0.95

1

1.05

1.1

1.15

1.2

1.25

1.3

1.35

1.4

1.45

1.5

8/05

/201

0 0:

00

15/0

5/20

10 0

:00

22/0

5/20

10 0

:00

29/0

5/20

10 0

:00

5/06

/201

0 0:

00

12/0

6/20

10 0

:00

19/0

6/20

10 0

:00

26/0

6/20

10 0

:00

3/07

/201

0 0:

00

10/0

7/20

10 0

:00

17/0

7/20

10 0

:00

24/0

7/20

10 0

:00

31/0

7/20

10 0

:00

7/08

/201

0 0:

00

14/0

8/20

10 0

:00

21/0

8/20

10 0

:00

28/0

8/20

10 0

:00

4/09

/201

0 0:

00

11/0

9/20

10 0

:00

18/0

9/20

10 0

:00

25/0

9/20

10 0

:00

2/10

/201

0 0:

00

9/10

/201

0 0:

00

16/1

0/20

10 0

:00

23/1

0/20

10 0

:00

30/1

0/20

10 0

:00

6/11

/201

0 0:

00

13/1

1/20

10 0

:00

20/1

1/20

10 0

:00

27/1

1/20

10 0

:00

Brukunga Mine Gauge V-notch, Medium Height per day in meters

Height Meters


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Figure 22 shows Dawesley Creek Brukunga Mine gauge levels had stabilised to around 4 to 7cm above gauge V-notch by early October 2010 after the extreme levels recorded in September 2010. The December 2010 survey occurred eight weeks after Dawesley Creek water levels stabilised and field observations confirmed that the catchment was still wetted sufficiently to permit baseflow at all sites on Dawesley Creek. Therefore, conditions present at the time of sampling were suitable for the persistence of healthy macroinvertebrate communities. There had been no shrinking of pools or formation of refuges that concentrate macroinvertebrates, which often leads to an overestimated health rating due to a concentration of animals. Therefore the results of this December 2010 survey give a good indication as to how the Dawesley Creek ecosystem is functioning post diversion. AusRivAS scores for spring edge models in December 2010 rated the reference sites and Brukunga Mine an ‘A’ (equal to reference) and McIntyre Road, Balyarta and the Freeway a ’B’(slight impairment to ecological health). These results reflect the current condition of the Dawesley Creek system, and the impact of previous and current AMD. Given the above-average flows of 2010 the ecosystem should have benefited once the hydrology stabilised allowing the development of a rich and abundant community similar to reference sites. This has only occurred at the Brukunga Mine in the AMD influenced sites and is most likely a result of an increased percentage of the sample needed to be examined microscopically, which in-turn increases the probability of discovering different small taxa, inflating the taxanomic richness of the site and also increasing the number of families discovered for use in the AusRivAS assessment. The stream bed of the Brukunga Mine site in December 2010 consisted of a thick layer of floc providing no habitat for macroinvertebrates. Those macroinvertebrates present were concentrated in the trailing bank edge habitat and consisted of some highly probable but missing taxa mentioned in previous reports. They included Turbellaria (flatworm), Oligochaetes (segmented worm), Physa sp. (freshwater snail) and Leptoceridae (caddis fly, Triplectides sp. & Lectrides sp.). The presence of these taxa in 2010 suggests that some recovery of the site may be occuring. An AusRivAS ‘B’ rating for Balyarta in December 2010 was the result of having collected 11 of 14.6 highly predicted taxa. The site recorded many other families that were not highly predicted by AusRivAS and this is a step towards a more diverse and biologically stable community. The taxa recorded at Balyarta, that were not highly predicted by AusRivAS, included Ferrisia sp. (freshwater limpet), Gyrinidae larvae (whirligig beetle), Cherax sp. (yabby) and three Odonata families (Hemicorduliidae, Lestidae and Coenagrionidae). McIntyre Road and the Freeway recorded 9 of 12 and 8 of 12 highly predicted AusRivAS families and, unlike Balyarta, these sites had few other families recorded. Taxa that were present were Hemicordulidae (dragon fly) at both sites and Coenagrionidae (damselfly) at the Freeway. Both of these sites have habitat constrictions which contribute independently to AMD to reduce taxanomic diversity. McIntyre Road is heavily shaded and has limited shallow water habitat, which in-turn limits primary production and reduces the number of ecological niches present. The Freeway site remains a monoculture of Typha sp. (bull rush), once again creating a single niche.


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If we utilise the highly predicted taxa for the December 2010 spring edge model we can determine, without bias, taxa to track in the future - especially if they are highly predicted at all sites and missing at some or all sites (Table 5). From this it is noted that freshwater snails (Hydrobiidae) are highly predicted and missing from all sites, and scuds (Ceinidae) and biting midges (Ceratopogonidae) are highly predicted and missing, or in low numbers at AMD influenced sites. Their absence or rarity is likely due to the long term effects AMD has had on Dawesley Creek with the strong suppression or local extinction of certain macroinvertebrates, possibly due to changes in the stream bed altering biological pathways of the system. Other taxa worthy of note are stick and micro-caddis flies from the families Hydroptilidae and Leptoceridae, and mayflies from the family Leptophlebiidae, Caenidae and Baetidae. Mayflies from these families were common at Nairne Creek prior to its alteration and have been recorded from Peggy Buxton Road. The establishment of populations of all of these particular macroinvertebrate types should be monitored into the future to determine if a more balanced community has developed, and thus determine if this aspect of the ecological health of the system is improving. There has been an increase in the observation of more primitive soft bodied macroinvertebrates. Historically, Oligochaete numbers have been low in the AMD affected regions of Dawesley Creek; however in December 2010 Oligochaetes frequently constituted a high percentage of the macroinvertebrate specimens found in samples (Appendix 1). Flatworms were also rarely recorded in AMD affected samples and now some are being recorded (Appendix 1). This is a positive sign that the lower end of the food chain is recovering. Although one Hydra was collected in 2009, none were recorded from AMD sites in 2010. The trend for a decrease in stream health has continued at Nairne Creek. Taxonomic richness at Nairne Creek has reduced greatly when compared to 2001, the year of similar hydrology to 2010, were in June, September and December taxa numbers were 39, 37 and 38 respectively; while in 2010 they were 27, 21 and 25. Nairne Creek edge and riffle samples pre 2008 nearly always received ‘A’ band ratings from AusRivAS, validating it for use as a reference site. From June 2007 onwards, stream health at Nairne Creek was significantly altered by a ford that was constructed at the site where previously the water flowed over a rocky section of road. Much of the riffle habitat was removed and, by September 2007, the main pool had reduced significantly. This was due to the base flow level being lowered by 25-30 cm by a pipe located at the base of the ford which drains the pool to a significantly lower level. The construction of the ford has changed the site, physically and hydraulically, to the point where comparisons with past data have been affected and the site should no longer be treated as a reference point. The 10 years of macroinvertebrate data for this site will be useful in helping to determine which macroinvertebrates are in the catchment and are likely to populate Dawesley Creek now and into the future. Riffles throughout the catchment in June and September continue to rate poorly with AusRivAS models rating all AMD influenced samples a ‘C’ (significant impairment to ecological health) and Nairne Creek in June a ‘B’ and in September a ’D’. In June recently-hatched stonefly


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nymphs were recorded from Brukunga Mine and Nairne Creek and there were black flies (Simuliidae) at Nairne Creek. Balyarta recorded no riffle-dependant species in June and the creek was too swollen in September to sample a riffle. In September one riffle-dependant macroinvertebrate was collected from Brukunga Mine a mature Gripopterygidae (stone fly) and none were recorded from Nairne Creek. The collection of samples: a) in September and b) shortly after many high flow events had the consequences of a) reducing the validity of analysing the sample data using the AusRivAS models and b) gathering an assemblage that reflected low richness and abundance resulting from the disturbance of flood events. If monitoring becomes more flexible there are a number of riffle taxa (highlighted in blue in Table 3) that are highly predicted to occur in riffles at these locations. These taxa are Gripopterygidae (stone flies), Simuliidae (black flies), Ceinidae (scuds), Hydrobiidae (freshwater snails), Leptophlebiidae (mayflies), Acarina (freshwater mites) Hydrobiosidae (clawed caddis flies) and Hydroptilidae (micro caddis flies). The return of these macroinvertebrate families needs to be monitored into the future to determine if recovery of riffle habitats is occurring. MVA indicated that the macroinvertebrate samples from sites which included Brukunga mine, Balyarta and the Freeway in December 2010 were similar to reference sites from 2001 and 2010. The September 2001 and 2010 samples grouped together possibly indicating an influence of high flow events on macroinvertebrate assemblages. AMD sites from 2001 and the March 2010 Brukunga Mine site which had a pH of 4.26 grouped closely. Macroinvertebrate assemblages from other samples appeared to be influence by the month and year in which they were collected (Table 6). The above average flows experienced during 2009 and 2010 would have ecologically reset the Dawesley Creek system. The flow would have mobilised sediments, widened stream banks (via erosion), introduced and removed nutrients, altered plant assemblages and moved many macroinvertebrates from refuges and distributed them throughout the system. These changes are all a natural part of stream function and a healthy system recovers quickly and benefits from such events. The Dawesley Creek system has been showing gradual improvement since the diversion became operational in 2003 and the recent hydrological influences may create a more natural and healthy macroinvertebrate assemblage during 2011 in Dawesley Creek. A negative aspect of recent above-average rainfall was the flushing of pooled acidic water from the 2 km stretch of isolated creek bed in Dawesley Creek. During the peak flows, when the diversion weir overflowed, the volume of water should have been great enough to dilute the acid water maintaining a neutral pH. This however would have caused the precipitation of suspended ionic metals and resultant smothering floc downstream of the diversion in Dawesley Creek.

6 THE FOLLOWING IS A SUMMARY OF KEY FINDINGS FROM

2010: • Parameters tested indicate the ecology of AMD sites may be improving since the

construction of the diversion in 2003.

• The reference site at Nairne Creek appears to have deteriorated since the road construction works carried out in 2007 and is less likely to be a suitable reference site.


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• Above-average rainfall is likely to have significantly impacted macroinvertebrate abundance and distribution within the Dawesley Creek system.

• “Equal to reference” AusRivAS results could be considered biased due to low macroinvertebrate numbers (as a result of sampling after high flows) in samples prompting a higher proportion of samples to be processed and hence more likelihood of additional small taxa being recorded.

7 RECOMMENDATIONS

In order to gain valid macroinvertebrate results, it is important that samples are collected within AusRivAS-defined seasons and that surface water is present at least 4 weeks prior to collection. Additionally, in the event of high flow or floods it is important that sampling take place 2-4 weeks after cessation of high flows, the interval being relative to the severity of the flow/flood event. In the past, to address these issues, a new research proposal for the monitoring of Dawesley Creek was presented to PIRSA Mine Rehabilitation in June 2009. The rationale for change was also based around selecting improved sampling sites that have more diverse habitat and less anthropological influences. It is the AWQC recommendation that the changes in this research proposal be instated during 2011 and beyond.


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8 REFERENCES

Anonymous (updated September 2001) SOUTH AUSTRALIA AUStralian RIVer Assessment System Sampling and Processing Manual http://AusRivAS.canberra.edu.au/man/SA/SA_Training_Manual.pdf

Coysh, J., Nichols, S., Ransom, J., Simpson, J., Norris, R., Barmuta, L. and Chessman, B. (2000). Macroinvertebrates bioassessment Predictive modelling manual. http://AusRivAS.canberra.edu.au/Bioassessment/Macroinvertebrates/Man/Pred/

Department of Water, Land and Biodiversity Conservation. Surface Water Archive. (2010) http://e-nrims.dwlbc.sa.gov.au/SiteInfo/ViewSiteData.aspx?id=A4260659&page=35 Hawking J. A. (2000) A preliminary guide to keys and zoological information to identify invertebrates from Australian inland waters 2nd

Marchant R. (1989) A subsampler for samples of benthic invertebrates. Bulletin of the Australian Society for Limnology 12, 49-52.

edition. CRCFE, Albury

McCune, B. and Mefford, M.J. (1999). PCORD. Multivariate Analysis of Ecological Data, Version4. MjM Software Design, Oregon.

PIRSA. (April 2004) Working Together newsletter http://www.pir.sa.gov.au/pages/minerals/references/brukunga/bnl_april_2004.pdf

Randall, J.E. and R.C. Cox (2004) 2003 Water Quality Monitoring at Brukunga, Licence Report to EPA

http://ausrivas.canberra.edu.au/man/SA/SA_Training_Manual.pdf�

http://ausrivas.canberra.edu.au/Bioassessment/Macroinvertebrates/Man/Pred/�

http://e-/�

http://www.pir.sa.gov.au/pages/minerals/references/brukunga/bnl_april_2004.pdf�


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APPENDIX 1

Temporal Changes at Each Site

Due to limitations within Microsoft excel, pH and taxonomic richness from 1996 to 1999 could not be displayed with the graphs illustrating 2010 data. The following graphs show pH and taxonomic richness from 1996 to 2004 for the six macroinvertebrate sites and their corresponding graphs in the report are Figures 9, 11, 13, 14, 16 & 17 respectively. In all the figures that follow, taxonomic richness for the different months is: yellow for March, blue for June, green for September and brown for December. Peggy Buxton Road

Taxon richness and pH from edge habitat at Peggy Buxton Road from 1996 to

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Brukunga Mine

Taxon richness and pH from edge habitat at Brukunga Mine from 1996 to 2004.

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Balyarta

Taxon richness and pH from edge habitat at Balyarta from 1996 to 2004.

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Taxon richness and pH from edge habitat at the Freeway from 1996 to 2004.

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Brukunga Mine Site

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