A Western Sydney University study has found toxic discharge from the Clarence Colliery in New South Wales is affecting the Heritage listed Blue Mountains area.
The research looked at the active underground coal mine, located near Lithgow, where contaminated surface runoff and mine waste flows into the protected World Heritage Conservation Area.
It analysed macroinvertebrate health and heavy metal concentrations – measuring the water quality and ecological health of the Wollangambe River and its tributaries close to the point of wastewater discharge. It found that the family richness of macroinvertebrates reduced by more than 63 per cent in areas below the mine compared to other reference sample sites.
The study identified higher levels of zinc and nickel in the Wollangambe River below the discharge area, which are known to be harmful for aquatic species.
It also found that sulphate concentrations were higher in areas below the mine than those located downstream at other coal mines in the Sydney Basin; 178 mg/L compared to 20.4 mg/L respectively.
Dr Ian Wright from the university’s School of Science and Health said coal mining has been a major industry in the Blue Mountains region for more than a century but there have been ongoing environmental impacts.
“When the Federal Government nominated for the Blue Mountains area to be listed as a World Heritage Area, it highlighted the important role of the NSW government’s Environment Protection Authority (EPA) in regulating coal mines,” he said.
“However the ongoing toxicity uncovered by this study highlights the failure of statutory process across two levels of government, and the lack of appropriate planning approvals and ongoing environmental pollution licensing.”
Wright added that the pollution from the mine extends for around 22km downstream, and also included increased salinity and thermal pollution.
“The mine’s waste discharge has strongly modified the river’s ionic composition, and is causing major impairment of the aquatic ecosystem,” Wright said.
Wright added that he has been in contact with the NSW EPA over the past two years and often shared these results with them.
“There are various statutory mechanisms at a federal and state government level that can provide protection to the Wollangambe River, the Wollemi National Park and more broadly the Greater Blue Mountains region from major activities such as coal mining,” Wright said.
“From a development approval and environmental pollution licensing perspective, the existing statutory mechanisms have failed to adequately protect the waterways and ecosystems, in spite of Clarence Colliery undergoing 18 license variations and two clean up notices since 2001.”