Water on the boil in Illawarra

SYDNEY Catchment Authority concerns over mining induced subsidence have been questioned by the industry

Water is on the boil in Illawarra. The Sydney Catchment Authority (SCA) says mining is having a negative impact on the Southern Coalfield’s ecological integrity.

“The authority is most concerned with mining induced subsidence and its impacts on water quality, water quantity, and the ecological integrity of special areas in the Southern Coalfields,” SCA general manager of catchment operations and major projects George Dodds told Australian Mining.

There is urgent need for more scientific data to assess mining’s effect on the Southern Coalfield’s water catchment, according to Dodds.

“There is very little scientific data available to help asses the nature and extent of mining’s impact on water quality and quantity,” he said.

“The SCA is calling for more scientific studies on the past and current impacts of mining on water resources, the attributes and environmental sensitivities of areas proposed for future mining, and the nature and extent of groundwater and its interconnectedness with surface streams and swamps.”

However, the peak body representing the NSW mining industry disagrees.

“Mining has taken place in the Southern Coalfield for many years, so the industry has been able to see how mining impacts water quality and quantity over time,” NSW Minerals Council director of external affairs Lancia Jordana told Australian Mining.

“This data has shown that while there have been impacts on surface water quality and quantity, they have generally been localised and temporary.”

“The quality of water in Sydney’s storage reservoirs has not been affected by mining in the Southern Coalfield.”

Little work has been done around the world on mining subsidence impacts in a water supply catchment, according to Dodds.

“Illawarra Coal prepares comprehensive impact assessments for each mining area, some costing more than $1 million each,” BHP Billiton Illawarra Coal spokesperson Rosanne Moore said.

With respect to the availability of short and medium term data, Moore says, Illawarra Coal has contributed substantial amounts of data which has been used to develop the most recognised and used subsidence prediction model for the Southern Coalfield.

“Detailed environmental monitoring data since 2001 provides a good understanding of medium to long term water quality effects from subsidence,” Moore said.

Long-term damage

The NSW Minerals Council recognises that there is genuine community concern regarding subsidence related impacts in the Southern Coalfield.

“There are, and there will continue to be, ecological impacts from mining, like other types of development and industry, but we need to assess whether they have any significance at the regional scale, and whether they can be remediated either naturally or using active techniques,” Jordana said.

“University of Wollongong (UOW) environmental scientist Mark O’Donnell says water quality professionals should communicate openly with regional communities on the science of water quality control.

“Water quality professionals generally do a good job of managing water quality when they have sufficient resources,” he said.

“What we don’t do well is keeping the community educated about water quality. Open and honest discussion of the issues is the way forward for the mining industry.

“Communities can make their own judgment on environmental, social and economic cost, and benefits when they understand the basic issues.”

Dodds agreed that open and transparent dialogue between the industry, the SCA, and the community will provide greater understanding of water quality control.

“Having an open and upfront dialogue is critical if the key stakeholders are all going to move forward at the same pace,” Dodds said.

Illawarra Coal supports the value of open and honest dialogue, Moore says, and keeps local communities informed of its operations and their impacts by providing monthly updates.

Remediation

O’Donnell emphasized that mining is not the biggest threat to water quality in the Illawarra.

“Urban development, agriculture, sewage treatment, and heavy industry have a greater impact on water quality than mining in this region,” he said.

“While our understanding of water quality interaction and our ability to predict change is increasing, there is still a lot of basic science to do.”

More work must be done, Dodds says, to understand the remediation needed in the Southern Coalfields.

“The SCA is interested in understanding the effectiveness and appropriateness of the remediation of these isolated and complex natural environments,” Dodds said.

Remediation strategies are an integral part of subsidence management, according to Jordana.

“Active remediation can speed up the natural recovery of ecological systems after disturbances caused by mining, and can be used where other impact prevention or mitigation measures are not feasible,” she said.

Moore says Illawarra Coal is looking to move away from a reliance on rehabilitation.

“Current mine layouts are designed to minimise environmental impacts such that rehabilitation is not required but is available as a contingency measure only,” Moore said.

O’Donnell was co-convener of the recent Illawarra Water Quality Symposium, held at UOW.

The Symposium was an important way for the community and key stakeholders to communicate over important water quality issues.

“Symposia like this are a useful way of keeping people up to date and connected,” he said.

The findings of the water quality symposium will be released before the end of the year.

UOW Professor of Environmental Science John Morrison, Mark O’Donnell, and Sandra Quin and will compile the publication.

The UOW School of Earth and Environmental Science (Geoquest), BHP-Billiton Illawarra Coal, Parsons Brinkerhoff, Cordo-Forbes Rigby and the Southern Rivers Catchment Trust sponsored the event.

Increasing base line data on the environmental systems in the Illawarra, Dodds says, will be an ongoing collaboration.

The NSW Government must decide what impacts are acceptable, Jordana says, when they are balanced with the economic and social benefits of a project.

George Dodds

Catchment Operations and Major Projects

Sydney Catchment Authority

George.dodds@sca.nsw.gov.au

www.sce.nsw.gov.au

Mark ODonnell

Environmental scientist

University of Wollongong

marko@uow.edu.au

www.uow.edu.au

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