Independent Expert Scientific Committee grave concerns Wallarah 2

An aerial view of the suburbs around and under which the Wallarah 2 coal mine will be locatedAn aerial view of the suburbs around and under which the Wallarah 2 coal mine will be located

The future of the Central Coast’s drinking water sits with the Federal Government, which will assess the Wallarah 2 Coal Project under the Environment Protection and Biodiversity Conservation (EPBC) Act, following the NSW Planning Assessment Commission’s determination in January that the mine was in the public interest.

Approval for the project will depend on Federal Environment Minister, Josh Frydenberg’s, decision about the mine’s impact on threatened species and water resources. In a letter to Federal Member for Dobell, Ms Emma McBride, the Minister said consideration would include advice from a 2013 Independent Expert Scientifi c Committee report. That Independent Expert Scientifi c Committee, in its 2013 advice to the Minister, said: “there are signifi cant risks associated with the proposed project having a detrimental and long-lasting effect on an already stressed water supply catchment. “The proposal is located within the Jilliby Creek Catchment, a major water source for the Gosford-Wyong Water Supply Scheme, which provides water to 285,000 people.

“The proposal has the potential to signifi cantly reduce surface runoff, with the project area covering fi ve per cent of the entire scheme’s catchment area. “The proposal has the potential to change surface and groundwater dynamics within the Jilliby Creek Catchment through subsidence related impacts. “Subsidence can lead to increased drainage between aquifers, altering water table heights, fl ow rates and water quality. “Groundwater dependent ecosystems, which rely on shallow water tables, have been identified along surface drainage channels within the project boundary. “Regular monitoring of the water table in these areas is needed to ensure that any variation in level can be resolved by remediation measures. “The predicted subsidence has the potential to alter fl ooding regimes, causing localised ponding/ damming of catchment runoff waters. “This has the potential to cause a change in depth of water bodies leading to inundation or waterlogging of emergent or marginal/riparian vegetation and causing aquatic habitat alteration due to draining or additional deepening of existing ponds, wetlands or dams.

“The proponent has indicated that fracturing as a result of subsidence will extend upwards to a maximum of 200 metres from the coal seam. “The potential impact caused by fracturing through the entire strata would have detrimental effects, including the reduction of surface flow and draining of shallow aquifers, on which groundwater-dependant ecosystems depend. “Findings need to be based on both localised modelling, and within a regional context, through robust analysis of similar projects in the area. “The forested hill areas of the proposed project are susceptible to surface deformation and cracking due to subsidence. “This has the potential to destabilise soils and sediments and mobilise these into creeks and streams increasing sediment loads and nutrient loads.

“The proposal indicates that brine and salt concentrate could potentially be stored below ground within the extracted coal seam. “Monitoring of groundwater quality, particularly in relation to the storage of salt concentrate, along with mitigation measures, would be required to ensure water quality is not degraded. “Contamination of the regional groundwater supply could have severe ramifications for the water quality of the Gosford-Wyong Water Supply Scheme. “Due to the potential risk involved, a rigorous groundwater monitoring system is needed to identify and then mitigate any impacts. “It is recommended that the proponent develop a post-mine management plan to reduce the impacts on water resources from continued depressurisation after mining.

“The predicted continued depressurisation 500 years after cessation is likely to impact the surrounding water extraction sources by creating a groundwater sink, having the potential to impact on existing groundwater bores and to contribute to cumulative impacts with surrounding mines. “There is insufficient evidence to support the proponent’s conclusion of negligible cumulative impacts. “In particular, the potential cumulative impacts brought about by the potential Mandalong Southern Extension Project are likely to have impacts within the Jilliby Creek Catchment. “It is recommended that an assessment of cumulative groundwater and surface water impacts be undertaken, incorporating, where possible, current and future mining and other extractive industries.

“The proponent’s assessments regarding the extent of aquifer connectivity are not justified by the data,” the committee concluded. “A regional water balance, which is considered essential to appropriately assess the regional cumulative impacts and risks to the Gosford-Wyong Water Supply Scheme, has not been provided. “The proponent has not considered the potential impacts on the surrounding creeks and water quality as a result of uncontrolled discharge from the mine operation’s dams. “The mine operation’s dams are currently designed to contain a 100 year average recurrence interval, 72-hour storm event. “ Consideration should be given to mine operation dams being redesigned to contain a larger storm event (one in 1,000 year average recurrence interval) to minimise the potential for downstream water quality and ecological impacts.

“Further assessment is recommended to gauge the extent of water interaction within the extraction boundary. “The proponent has assessed the calibration of the runoff model using a gauging station on Wallarah Creek. “It is noted that the station only operated from 1965 to 1976 and is not located within the main project area. “This dataset provides limited confidence in the calibration of the surface water balance.

“The proponent has stated that a water treatment plant will treat mine water to a quality that is similar to existing Wallarah Creek water quality values, before being discharged into the creek system. “Further clarification is needed on what the proponent specifies as ‘existing water quality values’ proposed for treated water released into the Wallarah Creek. “All site and surface water plans should be constructed in accordance with the National Water Quality Management Strategy. “The release of controlled treated mine water is likely to occur when there is no natural flow in Wallarah Creek, and these releases have the potential to change flow regimes of the creek. “The proponent has stated that Wallarah Creek will remain ephemeral in nature after water releases have been made. “It is suggested that an assessment be made on the potential impacts of extracting water from town sources, during extreme weather periods, including drought conditions.” The committee, in its key conclusions, found that relevant data and information had not been provided on the risks associated with the potential reduction of surface runoff caused by subsidence and the adverse effects on the Gosford-Wyong water supply scheme.

Other relevant data and information that had not been supplied, in the opinion of the Expert Scientific Committee included: the fracture potential of the strata between the targeted coal seam and the surface; changes to the regional water balance; the potential impacts of the project on aquatic ecology; and, cumulative impacts associated with current and future mines within the area. The committee advised the department and the minister that key methodologies and assessments that would be needed to fully assess the project, had not been provided. The missing methodologies included a regional water balance that gave particular consideration to both surface and groundwater impacts to the Gosford-Wyong water supply scheme, and assessment of subsidence issues associated with longwall mining, relating to the changing catchment characteristics, variation in groundwater aquifers and potential increased surface water and aquifer connectivity.

The proponent had also failed to produce “a comprehensive risk assessment of the impacts of the proposed project on surface water and groundwater dependent ecosystems”, according to the scientific committee.

Finally, the committee concluded that the Wyong Areas Coal Joint Venture had failed to provide “a cumulative impact assessment associated with creek systems flowing from the Mandalong Southern Extension Project directly through the proposed extraction site”. The committee said: “The draft Environmental Impact Assessment generally uses reasonable values and parameters in calculations, with the exception of the use of data from Wallarah Creek, in the water balance and the discussion on water quality. “The monitoring point located outside the proposed main extraction site may not be an appropriate calibration tool for the site water balance.

“A lack of supporting information on flood events and impacts on aquatic ecology has also limited the onsite assessments. “The proponent has relied heavily on literature reviews to provide analysis and assessments. “The committee considers that while the proponent has provided water resources and management information, there is limited information on the full suite of groundwater impacts; risks to the regional water balance; subsidence related impacts; impacts on aquatic ecology; and, the project’s risk to the Gosford-Wyong Water Supply Scheme.” Ms McBride said she called on Mr Frydenberg to intervene and use his powers to stop the mine.

“Minister Frydenberg has the chance to stop this mine,” Ms McBride said. “If he doesn’t, he’s not only ignoring our community, he is ignoring the advice of experts that clearly say this mine is a threat to our water catchment,” she said. “Our waterways are precious and this mine could have an impact for decades to come. “Minister Frydenberg reject this mine and do the right thing” she said

“The community opposes this mine and Labor opposes this mine,” said Ms McBride’s NSW colleague, the Shadow Minister for the Central Coast and Member for Wyong, Mr David Harris. “The NSW Liberals said they would oppose it, but so far they’ve done nothing but break their promise to the people of the Central Coast,” Mr Harris said. “If NSW Premier, Ms Gladys Berejiklian, won’t stand up for the Coast, hopefully, her colleague at the Federal level will,” he said. The Commonwealth Department of Environment and Energy has been called upon twice to assess the Wallarah 2 coal mine. The first application under the EPBC Act was made in 2007 and withdrawn in 2012.

The latest referral (2012/6388) was made in May 2012. On June 15, 2012, the federal department ruled that the referral was a controlled action and would be assessed by accredited assessment under the NSW Environmental Planning and Assessment Act. That meant the Federal Government would be mostly reliant on information from the NSW Government in making its determination. However, the EPBC Act includes a ‘water trigger’ that requires Federal Government approval of any coal seam gas or mining project that could have an impact on a water catchment. Wallarah 2 was, as a result, assessed by an Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development, and the final advice sent to the government in May 2013. In October 23, the then Minister, Mr Greg Hunt, confirmed that Sections 24D and 24E of the EPBC Act were controlling provisions for Wallarah 2.

“The controlling provisions relate to the impacts of coal seam gas development and large coal mining development on water resources. “The consequence of this decision is that the proposed action must be approved for the purposes of this controlling provision before it can proceed.” In October 2016, the applicant, Wyong Areas Coal Joint Venture, requested a variation to the proposal which was accepted by the Federal Department.

However, Mr Frydenberg and his department have not yet made their determination in relation to Wallarah 2 and the project cannot go ahead without Federal Government approval. Wyong Regional Chronicle has asked the Federal Department of the Environment and Energy for an update on the status of its EPBC Act assessment of Wallarah 2. Questions have also been sent to Mr Kenny Barry of Wyong Coal Pty Ltd about how the proponent has addressed issues raised by the Independent Expert Scientific Committee.

Source: Media release, Jan 23 Heather Robins, office of Emma McBride Website, Feb 2 EPBC Act referral 2012/3881 Department of the Environment and Energy

Similar stories