Point Fraser Monitoring and Evaluation Program

 

Summary

 

2014

 

Mark Lund, Michelle Newport, Jay Gonzalez-Pinto, Eddie van Etten, Pascal Scherrer, Rob Davis

History of Point Fraser

Point Fraser is named after the colonial botanist Sir Charles Fraser who explored the Swan River in 1827 when he accompanied Captain Stirling’s expedition. The site was originally named ‘Boodjargabbeelup’ by Noongar peoples, when it was still a peninsula. Prior to 2004, the site was a lawn area containing a car park, a helipad and a shipping container used for bike hire. A stormwater drain (Point Fraser Main Drain) discharged into the river at this point.

After 2000, the City of Perth sort to improve the quality of stormwater discharge to the Swan River and improve aesthetic, recreational and environmental values of the area. This culminated in the Point Fraser redevelopment; the first stage was the creation of a constructed wetland which was completed in 2004. The second stage saw the redevelopment of the remaining area which was completed in 2007.

The constructed wetland

The constructed wetland at Point Fraser is designed to treat stormwater prior to it entering the Swan River (Figure 1). Water enters the wetland from the catchment via a splitter box where low flows are directed into a bubble-up grate (BUG) in W1. High flows which might damage the wetland bypass the wetland and are directed to the River. These high flows typically contain relatively low contaminant levels. Water flows from W1 to W2 (Zone 1), and then when levels exceed those of the weir, water flows into W3 and then W4 (Zone 2) before exiting via a small pipe into the foreshore vegetation (Zone 3) and then into the River. W1 to W4 are lined to prevent interaction with underlying acid sulphate soils. W1 and W2 are covered with a thin layer (approx. 20 mm) of Supersorb activated zeolite clay, while W3 and W4 have an additional layer of soil to grow plants in. To prevent the wetland from drying in summer, water is pumped from Lake Vasto.

Figure 1.    Aerial photograph showing the movement of water (red arrows) through the Point Fraser constructed wetland. Yellow circles mark the fixed inlet and outlet monitoring structures. Sampling sites are indicated as W1 to W4. Imagery adapted from Google Earth, 2010.

The Monitoring Project

The City of Perth commissioned the authors to undertake a 5 year monitoring program to evaluate how the redevelopment was meeting its original objectives. Specifically to monitor, evaluate and report on the following:

  1. The effectiveness of the constructed wetland for treating stormwater;
  2. The quality of wetland habitat (vegetation) for biodiversity (aquatic macroinvertebrates and birds);
  3. Public usage of the reserve
  4. The success of foreshore revegetation.

This is the final annual report summary of the monitoring program and covers the period January to December 2014.

Main findings

  1. In 2014, backflow continued, however it could be estimated more accurately than in previous years and appears less significant than previously thought (Table 1).
  2. Approximately 5 – 10 kg of N and 0.2 – 0.5 kg of P were estimated to enter Point Fraser with approximately 9 kg of N and 0.8 kg of P exported to Zone 3. This represents a removal efficiency of -45 – 11% for N and 20 – 34% for P. Although inputs of N have not substantially altered from 2013, removal efficiency is poor with potential net export. Plants releasing N as a consequence of the high salinities back in 2012 are believed to be cause. It is likely that removal efficiency for N will improve in 2015 as the plants recover. This illustrates the limitations with using plants as the main uptake pathway for nutrients – under some conditions nutrients can be released. Phosphorus removal remains very high. Overall the wetland is working well at nutrient removal. Flows were only a small fraction of that which the wetland was designed for and this is likely enhancing nutrient removal.
  3. Wetland vegetation is growing well, however Juncus kraussii is now out-competing all other species and Baumea articulata and Typha domingensis are almost extinct within the wetland and Eleocharis acuta has a very limited distribution (Figure 2). The plants are now so thick that they are interfering with water flow through the wetland and action is needed to improve the water flow path.

Figure 2.    Map of vegetation types and other cover as of October 2014.

  1. Total N on a number of occasions (78% of samples) exceeded the target concentrations for discharge. Removal of P appeared successful in preventing exceedances of the target values for discharge (ANZECC/ARMCANZ, 2000; Swan River Trust, 2009a, b).
  2. As salinities within the wetland dropped, there is evidence that aquatic macroinvertebrate diversity returned to 2010 levels.
  3. Point Fraser does not appear to be a destination of choice for people but is used extensively by people exercising or parking to access the city. Most respondents viewed Point Fraser positively with 91% stating they would visit again. There was concern about the lack of facilities, although it was accepted that the commercial development may address these. A few respondents were not supportive of commercial developments at Point Fraser fearing their impact on the environment. The time taken for the commercial development to be completed was also identified as an issue by the majority of users. About a Bike Hire is a key driver for current recreational activities within the parkland.

Table 1.    Water and nutrient budget for the Point Fraser wetland, including removal efficiency for nutrients. Numbers in brackets are total inputs without losses due to backflow. Removal efficiency determined from total input (excluding backflow) and total output.

 

Water (m3)

N (g)

P (g)

TSS (kg)

Inflow

5,884-11,315

4,269 – 8208

249-479

297 – 571

Rainfall

3,606

967

76

0

Top-up from Vasto

7,215

2,768

812

0

Backflow

-2,107

-1,833

-105

-90

TOTAL INPUTS

14,598-20,029

6,198 – 10,110

1,032-1,262

207 – 481

Outflow

7,525

9,029

828

128

Evaporation

8,246

NA

NA

NA

TOTAL OUTPUTS

15,771

9,029

828

128

Removal Efficiency

 

-45 – 11%

20 – 34%

38 – 73%

 

Conclusions

Point Fraser was developed in 2004 to convert former lawn area to a recreation space, with environmental values. In addition, a wetland was constructed to intercept and treat a stormwater drain from East Perth (catchment 18.3 ha) that had previously discharged untreated into the Swan River.

  1. The quality of urban stormwater discharging to the Swan River long term, as a result of the redevelopment of Point Fraser by determining the amount of pollutant removal via the constructed wetland;
  1. The on-going ecological health of the constructed wetland via its conformance with relevant water quality guidelines and legislation requirements.

Results suggest that water quality is generally within the normal ranges that might be expected in stormwater wetland on the Swan Coastal Plain. A major issue over the 5 years of the project has been salt intrusion into the wetland from influx of saline Swan River water during high tides. It appears that the 2013 installation of a valve on the outflow from W4 has substantially reduced salt levels within the system.

The team has identified in previous years issues associated with the inlet structure that means that much of the water (46% of the total water inputs in 2012, 13% in 2014) that enters the wetland later drains back (backflow) into the drainage network, and as such it is effectively lost from the wetland. Backflow is not desirable simply as it would be more useful for the water to move through the wetland, adding to storage and dilution.

In 2014, the wetland was likely a net exporter of nitrogen with a removal efficiency of -24 to 26% but was effective at removing phosphorus (63-70%) and total suspended materials (41-76%). Total N on a number of occasions exceeded the target concentrations for discharge. Removal of P appeared successful in preventing exceedances of the target values for discharge.

Wetland vegetation has survived a series of low rainfall years and high salinities in the wetlands over the project; however Juncus kraussii is out-competing the other species, with all the others on the decline. Although Eleocharis acuta appeared healthy, the degree of coverage has declined substantially. Baumea articulata and Typha domingensis are almost extinct likely due to high salinities in 2012. The impact of the high salinities are only now being felt in low productivity in the plants, with excessive release of nitrogen. This illustrates the role that plants play in nutrient uptake – they are a nutrient pool rather than store. The sediment in W3 was substantially more effective at removing nutrients than the Supersorb clay in W2.

  1. The quality of wetland habitat and the quantity and quality of breeding places for native avifauna presence, behaviours and habitat use;

Biodiversity measured through bird and macroinvertebrate communities showed communities rich in cosmopolitan common taxa. A total of 37 bird species from 23 families have been recorded which is very encouraging given the scale of the wetland. Macroinvertebrate communities have largely recovered from the high salinities of 2012/13.

  1. The quality, quantity and type of recreational and educational use of Point Fraser by determining the diversity of visitor presence, behaviour, use, expectations and satisfaction and awareness of reports/information specific to Point Fraser performance;

Social monitoring was undertaken to see how people use the site. Point Fraser does not appear to be a destination of choice but is used extensively as people pass through it primarily for exercise or park in the car parks to access the city.

  1. The long term integrity and quality of the restoration of the foreshore edge, as a result of the redevelopment of Point Fraser by determining vegetation health and structural reliability.

Foreshore monitoring has revealed erosion and plant loss (including trees) along the foreshore particularly in area 1. Area 2 was largely inaccessible due to construction of the commercial development.

  1. References

ANZECC/ARMCANZ (2000). Australian and New Zealand guidelines for fresh and marine water quality, Volume 2. Aquatic ecosystems – rationale and background Information. Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.

Swan River Trust (2009a). Local Water Quality Improvement Plan: Mounts Bay Catchment. In: Swan River Trust, (Swan River Trust.Swan River Trusts Swan River Trust). Perth: WA Government.

Swan River Trust (2009b). Swan Canning Water Quality Improvement Plan. In: Swan River Trust, (Swan River Trust.Swan River Trusts Swan River Trust). Perth: WA Government.

Coal pit lake closure by river flow through: risks and opportunities

Mark Lund, Melanie Blanchette, Colm Harkin & Paul Irving

Project background

This project (C23025) builds upon the previous ACARP project (C21038) undertaken by the Mine Water and Environment Research (MiWER) Centre in Collie (Western Australia). In project C21038 we identified that nutrients were limiting algal productivity, water quality improvements, and the development of ecosystem values in coal pit lakes. Small catchments commonly associated with pit lakes appeared to limit natural inputs of nutrients – particularly carbon. Terrestrial leaf litter and other coarse organic material stimulated macroinvertebrate biodiversity. There were increases in taxa abundance and richness and algal productivity, in the pit lakes, despite no improvement in overall water quality. The Collie pit lakes are acidic (pH down to 2), with high concentrations of some metals (such as aluminium) and range from fresh to brackish, yet contain little sulphate. The outcomes of the previous ACARP project (C21038) suggest that developing environmental values (e.g., increasing aquatic biodiversity) could be a valid alternative to meeting (often difficult) water quality guidelines for pit lake closure criteria and subsequent relinquishment.

Connecting a pit lake to natural drainage lines could increase the effective catchment size of the lake. The South Branch of the Collie River was diverted around the pit that would eventually form Lake Kepwari. In 2011, the diversion around the lake failed during storm flows, allowing river water to pass through the lake before returning to the river downstream. Downstream water quality parameters were within ANZECC/ARMCANZ (2000) guidelines for the protection of 80% of ecosystem values. Additionally, the flow-through event appeared to have improved the water quality (increased pH) and environmental values (macroinvertebrate biodiversity) of Lake Kepwari. Following the 2011 breech, a three-year trial allowing the lake to be deliberately connected to the seasonal Collie River was approved by Department of Water (WA).

Project objectives

ACARP project C23025 will use this unique trial to assess the impacts of connecting a river to a pit lake, particularly on downstream aquatic ecosystems. This project is also a trial of the concept that increasing effective catchment size has a positive effect on lake ecology.

The seasonal Collie River is degraded by secondary salinization, resulting in occasional highly saline flows. In ACARP project C23025, we will also assess the effects of saline river water on Lake Kepwari.

The main objective of this project is to determine the risks and opportunities associated with diverting a river through a mine pit lake. Specifically, we will:

  1. Determine the downstream effects of pit-lake decant, with a particular focus on environmental and amenity values.
  2. Determine the effects river of inflow on environmental values and water quality within the pit lake. (Essentially a field-scale demonstration of a key finding from C21038 that larger catchments should enhance pit lake water and environmental quality).
    1. Understand the impact of variably saline river water on mixing within a moderately saline pit lake.
  3. Develop a national standard protocol for seasonal river monitoring that could be applied by the coal industry to manage river flow-throughs (either accidental or planned), as a part of mine closure strategy.

Current activities

To commence this project, we have focused on site selection for monitoring the Collie River South. Sites have to be readily accessible, representative of the aquatic habitats of interest, and reflective of the overall nature of the catchment. We have also identified another local flow- through system for inclusion in the monitoring program. This new system is a small stream – topped up by dewatering flows from Griffin Coal operations–that flows through Stockton pit lake. Increasing replication (i.e., 21 sites across two flow-through systems) will enhance our ability to detect the impacts of river flow-through on river and pit-lake systems. In the process we have identified an additional 30 riverine potential sites in the Collie basin that could be useful for future research.

Regular monitoring of Lake Kepwari (as part of the trial conditions) occurs quarterly and we have added a similar monitoring program for Stockton Lake. Currently we have sampled Lake Kepwari five times and Stockton three. Preliminary data from Lake Kepwari indicates that the lake is stratified continually by salinity, enhanced by temperature stratification. Conductivity of the bottom waters is highest in March and June, possibly due to saline groundwater inflows. River inflow between August and October appears to slightly dilute the bottom waters (although the exact mechanism is not currently understood). Importantly, bottom pH is >6 during October, but then appears to return to 4.5 by June probably due to incoming acidity from groundwater. The installation of continuous monitoring gear in both lakes should help clarify the processes responsible for these water quality changes. We have used off-the-shelf monitoring gear that provides detailed insight into physical (stratification) and chemical (light, temperature, conductivity and dissolved oxygen) changes in a very economical package that could be used in any pit lake.

Value-adding

We have also value-added to the ACARP project with Edith Cowan University- funded support for an assessment of the impacts of catchment activities (mining, agriculture) on aquatic microbes in the Collie catchment. In November 2014, we hosted colleagues from Montana State University (USA) with whom we are collaborating on the microbial work. The microbial work is likely to prove highly beneficial to the mining industry by providing an economic way of understanding microbially-mediated environmental processes as well as developing microbes as tools for environmental assessment. In April 2015, we visited our colleagues at Montana State University to discuss and test how methodological differences might influence the microbial analysis.

Knowledge transfer

A paper on approaches to pit lake closure, based on ACARP projects C21038 and C23025 was presented at the International Mine Water Association (IMWA) Conference in Xuzhou, China in 2014. A copy of the paper can be obtained for free from http://imwa.info/docs/imwa_2014/IMWA2014_Lund_720.pdf. Abstracts based on work conducted in C21038 and a poster on our microbial work have been presented at ICARD/IMWA 2015 in Chile. Presentations on previous and current ACARP projects were made to the Hunter Coal Environment Group (NSW) in February 2015.

Figure 1. Section of Melaleuca- dominated river typical of SW Western Australia (Collie River South flowing into Lake Kepwari). Figure 2. Creek flowing into Lake Stockton.

Wetland riparian vegetation structure of natural wetlands as guidelines to dredge pond rehabilitation, south-western Australia

Eddie van Etten (MiWER), Clint McCullough (MiWER), Mark Lund (MiWER), Mark Gell (KSS)

What is the vegetation structure of typical seasonal wetlands of the Kemerton region?

Silica sand mining by Kemerton Silica Sand Pty. Ltd. in the Kemerton region, south-western Australia, is followed by rehabilitation of mined lands into conservation areas after ore extraction is complete. Successful rehabilitation to a natural structure is involving first studies into what type of wetland (e.g., wetland riparian vegetation structure) is typical of the area, and hence acceptable as a rehabilitation outcome. Studies are focussing on both understanding natural wetland structure, dynamics and environmental drivers, on also on understanding how rehabilitation efforts are achieving desirable rehabilitation outcomes.

 

Photo: A typical seasonal waterbody of the Kemerton wetlands.


Photo: Dr. Eddie van Etten surveying vegetation rehabilitation success and rehabilitated slope topography and soil structure.


Figure: Topography, vegetation structure and soil structure profile of a seasonal Kemerton wetland.

Outputs

  • Van Etten, E. J. B.; McCullough, C. D. & Lund, M. A. (2014). Setting restoration goals for restoring pit lakes as aquatic ecosystems: a case study from south west Australia. Mining Technology. link
  • Van Etten, E. J. B.; McCullough, C. D. & Lund, M. A. (2011). Setting restoration goals for restoring pit lakes as aquatic ecosystems: a case study from south west Australia. Proceedings of the Eighth International Heavy Minerals Conference, Perth, Australia, 5-6 October 2011, pp. 339-350.  AusIMM, Melbourne. PDF
  • Van Etten, E. J. B.; McCullough, C. D. & Lund, M. A. (2011). Sand mining restoration on the Swan Coastal Plain using topsoil – learning from monitoring of previous rehabilitation attempts. Proceedings of the Eighth International Heavy Minerals Conference, Perth, Australia, 5-6 October 2011, pp. 323-338.  AusIMM, Melbourne. PDF
  • Van Etten, E. J. B.; McCullough, C. D. & Lund, M. A. (2012). Importance of topography and topsoil selection and storage in successfully rehabilitating post-closure sand mines featuring pit lakes. Mining Technology. 121: 139-150.link
  • van Etten, E.; McCullough, C. D. & Lund, M. A. (2009). Evaluation of rehabilitation efforts at the Kemerton Silica Sands Pty. Ltd. project area, November 2008. Report number 2009-02, Centre for Ecosystem Management/Mine Water Environment Research, Edith Cowan University, Perth, Australia. Unpublished commercial-in-confidence report to Kemerton Silica Sand Pty Ltd.
  • van Etten, E.; McCullough, C. D. & Lund, M. A. (2009). Riparian vegetation characteristics of seasonal wetlands in Kemerton, south-western Australia Report number 2008-17, Centre for Ecosystem Management/Mine Water Environment Research, Edith Cowan University, Perth, Australia. 50pp. Unpublished report to Kemerton Silica Sand Pty Ltd.


Geochemical Modelling of Pit Lake Water Chemistry to Support Management Decisions

Mike Mueller (Hydrocomputing, Germany), Katja Eulitz (Hydrocomputing, Germany), Clint McCullough (MiWER), Mark Lund (MiWER)

How does pit lake water quality and depth change under different management scenarios?

Stage 1. Selection of appropriate model

This model will maximise the use of the currently available data for model creation and validation. The current preference is not to focus on a single pit lake and model in detail but develop a simpler model that can be easily applied to cohorts of Collie pit lakes identified by the inventory collection and conceptual modelling. This general model would be less detailed but more suited to the low input knowledge environment of the Collie groundwater region and would support important pit lake and ground water management decisions.

Stage 2: Model parameterisation and testing.

There is no option for detailed validation of the model at this stage, other than through use of existing historic and collection of new data sets arising from Task 1.

Stage 3: Scenario testing.

A series of different scenarios will be run to demonstrate model outputs and to test alternative pit lake management and environmental strategies for the different pit lake cohorts.

 

    

Figure: Important processes in pit lakes


Model: Schematic of model coupling in MODGLUE

Modelling Tools

This project is using the model PITLAKQ which is a coupled model that combines the groundwater model PCGEOFIM, the lake hydrodynamic and water quality model CE-QUAL-W2 and the hydro-geo-chemical model PHREEQC.

PITLAKQ is capable of modelling all processes that are important to pit lake water quality. Fig. 2 shows these processes that include weather induced hydrodynamics with thermal layering, heath and gas exchange with the atmosphere as well as flow, transport and chemical changes in the subsurface. In addition, a wide variety of water quality processes in the lake water such as biological processes including algae growth and nutrient dynamics as well as equilibrium and kinetic chemical reactions can be modelled. Pit lake specific chemical reactions may be defined by means of an extendable hydro-geo-chemical database and rate limited reaction paths.

PITLAKQ has already been applied to a variety of different mining pit lakes under different scenarios, producing results to guide surface and groundwater management.


Video: Model of Lake Kepwari during filling showing temperature changes


Video: Model of Lake Kepwari showing pH changes during filling

Outputs

Müller, M.; Eulitz, K.; McCullough, C. D. & Lund, M. A. (2010). Mine Voids Management Strategy (V): Water Quality Modelling of Collie Basin Pit Lakes. Department of Water Project Report MiWER/Centre for Ecosystem Management Report 2010-10, Edith Cowan University, Perth, Australia. 95pp. Unpublished report to Department of Water. link

McCullough, C. D.; Müller, M.; Eulitz, K. & Lund, M. A. (2011). Modelling a pit lake district to plan for abstraction regime changes. Mine Closure 2011: Proceedings of the Sixth International Conference on Mine Closure. Lake Louise, Canada. Fourie, A. B.; Tibbett, M. & Beersing, A. (eds.), Australian Centre for Geomechanics (ACG), Perth, Australia, 581-592pp. PDF

Müller, M.; Eulitz, K.; McCullough, C. D. & Lund, M. A. (2011). Model-based investigations of acidity sinks and sources of a pit lake in Western Australia. Proceedings of the International Mine Water Association (IMWA) Congress. Aachen, Germany. 41-45pp. PDF

 

Ecotoxicity limitations following liming and nutrient enrichment to remediate acid mine lakes

Clint McCullough (MiWER), Luke Neil (Curtin), Mark Lund (MiWER), Jess Sackmann (CWR, UWA), Dr. Anas Ghadouani (CWR, UWA), Dr. Yuri Tsvetnenko (Curtin), Dr. Jim Ranville (DCG-Colorado School of Mines), Prof. Louis Evans (Curtin)

Is liming and enhanced primary production able to reduce ecological toxicity and increase biodiversity of Collie lakes?

Twelve 1,200 L mesocosms at ECU have been filled with a 40 mm layer of lake sediment from the bottom of the fast river-filled Lake Kepwari. This representative sediment layer has then been covered with Lake Kepwari water. Treatments have been allocated in a randomised two-way factorial design to test the effects of liming, phosphorus enrichment and combined liming and phosphorus amendment on different aspects of the AMD water chemistry, ecotoxicity and ecology.

                             Not limed    Limed

No nutrients    U U U    U U U

Nutrients            U U U    U U U

Figure: Experimental Design

Photo: Collecting sediment from Lake Kepwari


Photo: The mesocosms back established at ECU

This was a collaborative multidisciplinary project with co-supervised students at Curtin University of Technology and University of Western Australia. The Edith Cowan University team examined water chemistry, sediment and periphyton dynamics, including the effect of liming and enhanced primary production upon dissolved heavy metal and nutrient concentrations, alkalinity and pH. Jess Sackmann examined correlations between phytoplankton community water quality, and Luke Neil examined the effect of different treatments on aquatic ecotoxicity between each other and over time.

Funding:

Part of L. Neil’s Ph.D. project and J. Sackmann’s Honours Project. Partially funded by Curtin, Edith Cowan, UWA and the Centre for Sustainable Mine Lakes.

Outputs:

Neil, L. L. (2008). Bioassay assessment of mine pit lake water for aquaculture and biodiversity conservation, Ph.D. thesis, Curtin University of Technology, Perth, Australia. 298pp. link

Neil, L.; McCullough, C. D.; Lund, M.A.; Tsvetnenko, Y. & Evans, L. (2009). Bioassay toxicity assessment of mining pit lake water remediated with limestone and phosphorus. Ecotoxicology and Environmental Safety. 72: 2,046-2,057.link (Highlighted article).

Neil, L.; McCullough, C. D.; Tsvetnenko, Y. & Evans, L. (2006). Toxicity assessment of limed and phosphorus amended mine pit lake water. RACI/ASE Interact 2006 conference. Perth, Australia 24-28 September. PDF

Sackmann, J. (2006). The effect of experimental liming and nutrient addition on phytoplankton of an acidic mine lake, B.E. (hons) thesis, University of Western Australia, Perth, Australia. 50pp.

Ecology of black-stripe minnow (Galaxiella nigrostriata, Pisces: Galaxiidae) in remnant populations on the Swan Coastal Plain, Western Australia

Dave M. Galeotti (MiWER), Clint McCullough (MiWER), Mark Lund (MiWER), Mark Gell (KSS)

What habitat requirements does a fish that live in seasonal wetlands have and how does this relate to rehabilitating these wetlands from mining?

The south-west of Western Australia is home to only ten native species of freshwater fish. Of those ten, eight are endemic and two of those species live in seasonal wetlands (most fish live where water is permanent!) One of those species, the black-stripe minnow, Galaxiella nigrostriata, is currently known only to exist in three locations in WA: Melaleuca Park near Perth, Kemerton near Bunbury and between Augusta and Albany. While the ‘southern’ distribution mainly occurs within National Parks, the two remnant populations are not as protected.

My research will look at what factors decide their habitat choice and ultimately what they require to survive. The information gathered will help direct the conservation and rehabilitation of wetlands for this unique species by understanding their ecological requirements. With a continuing. drying climate and further pressures on the wetlands from development and groundwater extraction, research into this fascinating fish is of great importance. Wetlands on the Swan Coastal Plain have a history of being filled, drained and/or degraded for agriculture, mining, urban sprawl and industrial uses. For example, one remnant population is on the project area of a sand mine. Luckily, the mining company is being proactive in their conservation efforts by funding research such as this.

There are four study components to my project: habitat and diet preferences, aestivation requirements and population genetic structure. The first three can be classed as the ecological requirements of the fish and the genetic component stands alone as an overall species management issue. Study results will provide information to help conserve this threatened species, direct wetland rehabilitation requirements on the mine project area and may be used to identify habitats likely to contain ‘new’ populations.

     

Photos: A seasonal wetland that only sometimes contains black-stripe minnow. September (left) and January (right).


Photos::Minnows are thought to aestivate in Koonac crayfish burrows

Funding:

Part of D. Galeotti’s MSc project. Funded by Kemerton Silica Sands

Outputs:

Galeotti, D. M.; McCullough, C. D. & Lund, M. A. (2010). Can meta-population theory explain survival of an aestivating fish species in a seasonal wetland complex? 31st Congress of the International Association of Theoretical and Applied Limnology. Cape Town, South Africa. 12–18 August. Societas Internationalis Limnologiae (SIL). PDF

Galeotti, D. M.; McCullough, C. D. & Lund, M. A. (2009). Can meta-population theory explain survival of an aestivating fish species in a seasonal wetland complex? Australian Society for Limnology 2009 Congress. Alice Springs, Australia. PDF

Galeotti, D. M.; McCullough, C. D. & Lund, M. A. (2010). Black-stripe minnow Galaxiella nigrostriata (Shipway 1953) (Pisces: Galaxiidae), a review and discussion. Journal of the Royal Society of Western Australia 93: 13-20. link

Galeotti, D. M.; McCullough, C. D. & Lund, M. A. (2008). A synthesis of Black-striped Minnow (Pisces, Galaxiidae: Galaxiella nigrostriata) ecological requirements, south-western Australia. Centre for Ecosystem Management Report 2008-12. Edith Cowan University, Perth, Australia. Unpublished report to Kemerton Silica Sand Pty Ltd. PDF

Galeotti, D. M., Castalanelli, M., Groth, D. M., McCullough, C. D. & Lund, M. A. (2014). Genotypic and morphological variation between Galaxiella nigrostriata (Galaxiidae) populations: implications for conservation. Marine and Freshwater Research.

Article on WA Science Network entitled WA’s back-stripe minnow research continues link

Article on ABC News link

Conceptual Modelling of Pit Lake Processes and Ecological Risk

Clint McCullough (MiWER), Mark Lund (MiWER)

Conceptual modelling to better understand ecological risks posed by pit lakes

To ensure greatest scientific robustness of conceptual models we held a site visit and workshop in Collie with an expert panel of scientific researchers and managers from universities and State regulatory staff to best understand how these processes are likely working in different pit lakes. This workshop identified conceptual model needs e.g., a carbon cycling model and an acidity budget model. The intent is to then present the conceptual models as diagrammatic representations highlighting the nature of relationships between parameters and processes. These models will also be used to develop cohorts of similar pit lakes for later empirical modelling.


Photo: How does acidity enter Collie pit lakes? (Lake Kepwari)


Figure: Example conceptual modelling of pit lake chemistry

Funding: Department of Water (Western Australia)

Outputs

McCullough, C. D. & Lund, M. A. (2010). Mine Voids Management Strategy (IV): Conceptual Models of Collie Basin Pit Lakes. Department of Water Project Report MiWER/Centre for Ecosystem Management Report 2010-12, Edith Cowan University, Perth, Australia. 95pp. Unpublished report to Department of Water. link

McCullough, C. D. & Van Etten, E. J. B. (2011). Ecological engineering of a novel lake district: new approaches for new landscapes. Mine Water and the Environment. 30: 313-319.link

Assessment of the Effects of Pit Lakes on Human Health

Andrea Hinwood (CEM), Jane Heyworth (UWA), Helen Tanner (CEM), Clint McCullough (MiWER)

Do pit lakes present a hazard to human health?

Government and community stakeholders have expressed concerns about how open cut mining operations may affect human health and wellbeing through modified surface and groundwater regimes and their follow-on effects on environmental contamination and disease propagation. This project used Collie as a case-study to investigate how the formation of pit lakes may degrade or even improve health outcomes for mining communities living with these legacies.

This project aimed to examine possible impacts of human interaction with pit lakes. The project was conducted in three stages. The first was a literature review of the health effects of the aspects of pit lakes including chemical contamination, pH and also injury. The second stage of the work attained an understanding of how and how frequently the community was exposed to the pit lakes leading to the third stage, an assessment of the risks of exposure and health impacts. Stage 3 produced a screening health risk assessment identifying risks, management strategies, including management trigger levels to ensure protection of human health.

 


Photo: Sulfidic minerals release acidity and metals as AMD in Collie pit lakes


Photo: Black Diamond pit lake highwalls create a realised drowning risk

Stage 1:  Literature review of historic and new Collie pit lake characteristics, data collation of existing information and assessment of health impacts of identified parameters.

This stage required the compilation of existing data on the chemical, physical and biological aspects of Collie pit lakes from the peer reviewed and available grey literature. As there was little data publicly available on Collie pit lakes, this data compilation made extensive use of unpublished MiWER data. Project members from the MiWER team have an extensive dataset on water quality of most Collie pit lakes extending back more than a decade and also collected new data specifically for the health study. In addition, existing monitoring data was used to determine concentrations of relevant parameters and their likely health effects. The literature review outlined likely health effects associated with water temperature and other issues such as chemical injury. The data collated in Task 1 were used to identify potential chemical and biological human health risks associated with pit lakes in Collie. A further literature review also examined physical risks such as injury, water temperature and drowning.  

Stage 2:  Community Survey

To assess the use and perceived issues of using pit lakes a community survey was undertaken via administration of a postal questionnaire. The questionnaire was focussed on finding out how many people use the pit lakes, the purposes for which they use the lake, how often they use the lakes and for how long they have used the lakes and how they would like to use the lakes. We also obtained data on health issues that may be associated with pit lake water and other potential confounding factors. The questionnaire was designed based on the literature review. The population of Collie and surrounds is 7,194 persons and we aimed to obtain information from approximately 10% of the population. As response fractions are often low 1,500 questionnaires were posted to a random sample of residents of Collie. The selection was based on the electoral roll. A reply paid envelope was provided. The data collected via questionnaire was analysed and the information informed the screening health risk assessment in Stage 3. A report on the questionnaire was then developed and provided the Department with a variety of information on actual and perceived issues associated with pit lakes in the area. 

Stage 3:  Screening Health Risk Assessment.

Health risk assessment is a systematic, transparent process of assessing the potential risks associated with exposure to environmental and physical parameters. It uses a standard methodology which is routinely accepted worldwide and provides managers with good information on how to prevent and minimise both actual and perceived risks. Based on Stages 1 and 2 human health risks were determined based on the likelihood of them occurring, the consequence if they occur and therefore an assessment of the significance of the risk. This process also enabled the development of triggers to manage issues to prevent risks from occurring. This stage also identified any issues that required further investigation.

Funding: Department of Water (Western Australia)

Outputs

Hinwood, A.; Tanner, H.; Heyworth, J.H.; McCullough, C. D. & Lund, M. (2010). Water quality of mine void pit lakes used for recreation. 2010 Joint Conference of International Society of Exposure Science & International Society for Environmental Epidemiology. Seoul, Korea. International Society of Exposure Science (ISES) and the International Society of Environmental Epidemiology (ISEE).PDF

Hinwood, A.; Tanner, H.; Heyworth, J. & McCullough, C. D. (2010). Recreational use of acid mine pit lakes. 2010 Joint Conference of International Society of Exposure Science & International Society for Environmental Epidemiology. Seoul, Korea. International Society of Exposure Science (ISES) and the International Society of Environmental Epidemiology (ISEE). PDF

Hinwood,A.; Heyworth, J.; Tanner, H. & McCullough, C. D. (2012). Recreational use of acidic pit lakes – human health considerations for post closure planning. Journal of Water Resource and Protection. 4: 1,061-1,070 link

Hinwood, A. L.; Heyworth, J.; Tanner, H. & McCullough, C. D. (2010). Mine Voids Management Strategy (II): Review of potential health risks associated with Collie pit lakes. Department of Water Project Report MiWER/Centre for Ecosystem Management Report 2010-11, Edith Cowan University, Perth, Australia. 111pp. Unpublished report to Department of Water. link

Use and Water Quality Remediation of Acidic Coal Pit Lakes by Adjacent Aquaculture

Clint McCullough (MiWER), Naresh Radhakrishnan (MiWER), Mark Lund (MiWER), Xanti Larrañaga, (MiWER), Digby Short (Premier Coal Pty Ltd)

Can a nearby aquaculture discharge be used to both remediate an acidic pit lake and also to provide a sustainable source of water for a post-mining industry?

The aim of this competitively-funded research programme is to examine how a coal mine pit lake could supply feed water and accept waste discharge from a commercial scale aquaculture venture as part of a sustainable post-mining community without significant deterioration in the lake environment e.g., water quality. This project also intends to answer whether water quality in coal mine pit lakes would be improved by accepting wastewater from a commercial scale aquaculture venture through simulation of microbial remediative processes previously inhibited by low nutrient concentrations. Specific objectives of this study therefore will determine:

  • The capacity of a coal mine pit lake to accept aquaculture waste discharges without detrimental impacts to pit lake water quality or wildlife.
  • How improvement of water quality and wildlife values might occur through aquaculture waste discharges remediating key pit lake water quality issues such as acidity by addressing insufficient nutrient concentrations.

 

Photo: The marron grow-out ponds adjacent to Collie pit lake WO3.


Photo: An adult marron crayfish from Collie.

Outputs

Kumar, R. N.; McCullough, C. D. & Lund, M. A. (2011). Use and water quality remediation of acidic coal pit lakes by adjacent aquaculture. Report number 2011-10. Mine Water Environment Research Centre/Centre for Ecosystem Management, Edith Cowan University, Perth, Australia. 104pp. Unpublished report to Australian Coal Association Research Programme (ACARP).

Kumar, N. R.; McCullough, C. D.; Lund, M. A. & Larranãga, S. A. (2011). Evaluating the factors limiting algal biomass in acidic pit lakes of the Collie Lake District, Western Australia. Proceedings of the International Mine Water Association (IMWA) Congress. Aachen, Germany. 523-527pp.

Remediation of waters from a south-west Australian acid pit lake with oxic liming and an aerobic wetland

Clint McCullough (MiWER), Mark Lund (MiWER), David Bills (Griffin Coal)

Does treatment with oxic liming and an aerobic wetland remediate mine waters from a new acid pit lake?

A mine water treatment system was constructed at Griffin Coal Mining Company Limited in Collie Western Australia, to remediate acidified mine lake water from the nearby Chicken Creek pit lake (pH 3, containing approximately 8 million m3 of water) and make it suitable for cultivating plants or fish.

The first part of pit water treatment is a two-stage liming system utilising a fluidised bed of limestone. At each stage of liming there is a settling pond to remove particulate iron- and aluminium oxyhydroxides. From here the limed water gravity-feeds back to the lake though 5 ha constructed aerobic “polishing” wetland.

Photo: Fluidised liming of Chicken Creek pit lake water


Photo: Aerobic polishing of fluidised Chicken Creek pit lake water

This study is evaluating the way in which fluidised liming and aerobic wetland treatment can remediate pH and elevated metal concentrations in water from a typical recently groundwater-filled acid pit lake of Collie. Both water chemistry analyses and toxicity teas are being undertaken to evaluate water quality at each stage of treatment in order to better understand the processes taking place in this treatment system. The conclusions and recommendations of this project will enable better design of such systems for this mining region.