Working for the Rivers

For 15 years, Ian Wright’s research has helped keep coal mine pollution out of the waterways of the Sydney region.

Ian Wright’s research often starts with a tip-off from community groups. That’s how this Western Sydney University water quality expert became involved with stemming the flow of pollution from a coal mine in the Southern Highlands of New South Wales into Sydney’s main water supply.

As well as being home to Australia’s largest city, the 3.6 million-hectare Sydney Basin hosts coal mines, industry and environmentally sensitive locations such as water catchments, national parks and wilderness areas. One such mine, the Berrima Colliery was shut down in 2013 after operating continuously for more than a century. But, a local community group had become concerned about ongoing discharge into the nearby Wingecarribee River, which flows into Warragamba Dam. In 2014, they asked Wright to investigate.

Australia’s most published scientist on water pollution from coal mines, Wright heads a water quality lab at the University’s Hawkesbury campus. For 15 years, Ian and his team have been working to alleviate the impact of coal mines on rivers in the Sydney Basin.

The team’s interest in the old mine deepened soon after the community approach about Berrima when NSW Environment Protection Authority (EPA) officers also raised concerns during one of Wright’s regular meetings with the agency about discharge into the Georges River from another coal mine, the Westcliff Colliery.

At the time, Westcliff was one of five collieries in the Sydney area from which Wright’s team was regularly collecting discharge samples. He had been exchanging notes about the poor quality of Westcliff’s discharge with the agency and the mine’s owner, South32, for about five years. Prompted by Wright’s observations, South32 recently built a $10 million water treatment facility for all their mines in the Westcliff area.

The impact of this facility has been significant. “The final effluent is brilliant,” Wright comments enthusiastically. “You could probably drink it!”

World leaders

Wright and his team’s work with the EPA and other stakeholders has improved the NSW government’s environmental regulation of coal mines, and is now considered an exemplar of international best practice in environmental regulation.

The Westcliff win was followed by another important project involving the EPA. Based on the results of research by Wright’s team, the agency issued a revised environmental licence in March this year for the Clarence Colliery, which discharges into the Wollangambe River. It’s thought to be the most stringent licence ever issued to an Australian coal mine.

Most recently, the Berrima Colliery became the latest addition to the suite of mines under Wright’s watchful eye when he, PhD student Nakia Belmer and third-year environmental science undergraduate Ben Green began collecting water samples from the Wingecarribee above and below where the Berrima mine drainage enters. Within a few months it was clear that something was wrong. 

With each set of samples, the pollution was becoming worse. Acidic mine drainage was increasing and so too was the leaching of heavy metals. 

“The most incredible thing was that no one was monitoring it and able to assess its impact until we came along and did our research,” Wright says. The existing EPA licence didn’t set discharge limits on he metal pollutants coming out of the mine, so the most toxic and dangerous pollutants were unregulated, he says.

And although the agency required the company to measure pollution upstream and downstream, the downstream sampling was about 5km from the discharge – by which point, the pollution was not detectable.

Just before Christmas 2016, Wright met with the EPA, the NSW Department of Resources and Energy and Boral, which owns the Berrima mine, to alert them to the chemical contamination.

Need to know

  • Tip-offs from the community revealed river pollution from coal mines
  • WSU research undertook long-term river monitoring
  • WSU recommendations were adopted by authorities and industry

Then, in February 2017, Wright’s team returned to study the impact on insect life in the river system. “When we got the invertebrate results we realised the ecosystem was really sick...the river below the discharge was dying,” Wright says.

Levels of key indicator organisms were much lower than expected. Mayflies, stoneflies and caddisflies, three groups with nymph or larval stages that develop in river beds, had dropped by 90 per cent in the water immediately downstream from the discharge site compared to the stretch above it.

Boral responded to the report and is evaluating the best way to treat the mine’s discharge. Even though the mine is no longer operating, the company has installed a new underground treatment system to capture pollutants in the mine’s waste water.

“I’m ecstatically happy,” Wright says. “It’s the first mine I’ve heard of in Australia that’s shut down and the coal miner is now going back in to fix it.”

In fact, Boral is keen for Wright to remain involved and will take him underground at Berrima to show him the treatment system when it’s up and running. The company has also provided the team with access to their own records of the mine’s water chemistry before and during closure. Combined with the post-closure data, it’s allowed the team to look at the process in a way that’s never been possible previously anywhere else in the world.

“[This provides] unique information on the relative changes in water chemistry through the coal mine closure process,” Wright explains. And this may become increasingly valuable with many of the world’s coal mines now facing closure as energy demands shift due to global reduction requirements in carbon dioxide emissions. 

Credit

© Albert Chetcuti, © Phillip Minnis / Alamy Stock Photo
Future-Makers is published for Western Sydney University by Nature Research Custom Media, part of Springer Nature.