New research shows improvements in Wollangambe water quality

A team of scientists from Western Sydney University, led by Dr Ian Wright, have published research indicating remarkable ecological recovery in the river, which flows through the Blue Mountains at its north-western reaches. Water quality has improved substantially, while animals have returned to the area too.

Dr Wright and his associates first studied the river in 2014, revealing a complex pollution problem, with the amount of zinc and nickel in the water of particular concern. The contamination was put down to wastewater from the nearby underground coalmine Clarence Colliery

According to an article Dr Wright penned for The Conversation, these levels were at 10 times the known safe levels. The 2014 research found that the metals had a severe impact on flora and fauna along the river.

This led to a campaign, in partnership with the Blue Mountains Conservation Society, directed at the Environmental Protection Agency (EPA) to implement measures and regulations to enforce the colliery to reduce its pollutants. In 2020, the EPA did impose stringent regulations on the colliery.

"And it worked!" wrote Dr Wright. "We collected samples 22 kilometres downstream of the river, and were very surprised at the speed and extent of ecological recovery. Not only has water quality improved, but animals are coming back, too.

"The improved treatment resulted in a very significant reduction of zinc and nickel ... in the mine's wastewater, which continues to be closely monitored and publicly reported by the colliery."

However, Dr Wright warned that there is a long way to go, stating: "River sediments remain contaminated by the build-up of four decades of zinc and nickel enrichment, up to two kilometres downstream of the mine outfall ... To help speed up the recovery, contaminated sediment should be removed from the river below the mine outfall, similar to a 12-month clean-up operation conducted after a major spill from the mine in 2015."

Dr Wright emphasised to the Gazette the vital role that the Blue Mountains community played in putting pressure on authorities.

"The involvement of the Blue Mountains community is a major reason why the pollution in the Wollangambe has been addressed, and is now falling," he said.

"In August 2014, the Wentworth Falls School of the Arts hall was packed, organised and advertised by the Blue Mountains Conservation Society.

"At this meeting my PhD student, Nakia Belmer, and I explained about the scale and extent of pollution in the river. We pointed out that the wastewater from the colliery was poorly treated and reflected inadequate regulation of this river flowing through the heart of the World Heritage Area.

"The community kicked into action and wrote letters to the EPA. Many community members attended meetings with the EPA. This was very influential, and it has helped me form my view that not only are the community the 'eyes and ears' for the environment - they are also the custodians. The Blue Mountains community have demonstrated that for more than 20 years."

The Blue Mountains Conservation Society echoed Dr Wright's delight that the river's water quality had improved, but acknowledged that careful management of the river is still required.

"The society has a long-held interest in the water quality in the Blue Mountains and the impact of mining discharge on the fish, invertebrates and aquatic ecosystems," said president Tara Cameron.

"The work of Dr Wright and his students was instrumental in revealing high levels of heavy metals from Clarence Colliery entering the river.

"Dr Wright's work shows how the health of the river has improved and is important in giving the community hope that their efforts can make a difference.

"The society now asks that the EPA continue the positive work to limit the levels of salinity entering the Wollangambe, which still remain very high. This river has near pristine headwaters above the discharge point and high levels of salinity continue to have a negative impact."

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