1 month ago
7
January 29, 2026 — 5:00am
Dirty water from coal mining near Lithgow has polluted a major river in the Sydney drinking water catchment, the environmental watchdog has found.
The NSW Environment Protection Authority issued a clean-up notice to Centennial Coal’s Springvale mine after finding huge spikes in the salinity of the Coxs River, downstream from a discharge point used by the mine.
The Coxs River, a high-conservation river that flows for 60 to 70 kilometres through the Blue Mountains World Heritage Area and into Warragamba Dam, is impacted by several coal mines, as well as the Mount Piper power station and the now-closed Wallerawang plant.
An EPA spokesperson said it required Centennial Coal to reduce the overall volume of water being discharged into the environment. The clean-up notice issued on January 23 has progressive deadlines between now and May.
“The NSW EPA acknowledges community concerns about the environmental impacts of coal mining in the region and is committed to using its regulatory powers to minimise these impacts,” the spokesperson said.
The dirty mine water was stored in Cooks Dam and released into Wangcol Creek at the LDP001 discharge point, which Professor Ian Wright, a water scientist at Western Sydney University, described as “the most poorly regulated waste discharge” he knew of.
A common measure of salinity is electrical conductivity, which the EPA said exceeded Australian guidelines on two dates – up to 4270 microsiemens per centimetre (μS/cm) on one occasion, based on the coal company’s own monitoring.
“The clean creeks of the Blue Mountains are under 50 μS/cm, when you get a bit of human habitation it’s a few hundred – and 4000 is just colossal,” Wright explained.
“I’ve been looking at this for years and years and years; there’s basically a plume of salinity that goes from this site all the way down the Coxs River on its journey into Warragamba Dam.”
Wright said there was no legal limit to the salinity of discharge into creeks, but he hoped the EPA would regulate it in the future. The agency’s description of the salinity spike as a pollution incident marked “a change in tone”, he said, as the issue was previously ignored.
Warragamba was the most saline of Sydney’s drinking water reservoirs, though within safe limits and far better than many towns around Australia, Wright said. His main concern was the health of the Coxs River, which was habitat for platypuses and other flora and fauna.
Wright also called for tighter controls on specific pollutants such as zinc and nickel, calling the current limits “a licence to pollute”. For example, Centennial reported its latest discharge had 377 micrograms of nickel per litre of water. This was under the EPA licence limit of 500 micrograms, Wright said, but well above the threshold of 10 micrograms where it became dangerous to aquatic life.
Jacqueline Mills from the Nature Conservation Council said the EPA had taken seriously the reports of members of the public, including the Lithgow Environment Group, and the clean-up notice was “a step in the right direction”.
She noted underground coal mining also drained swamps and caused subsidence, threatening the unique rock pagodas of the nearby Gardens of Stone area.
“The location of those coal mines in the Lithgow region, in a highly environmentally sensitive area, is regrettable,” Mills said.
Centennial Coal did not respond to requests for comment.
Get to the heart of what’s happening with climate change and the environment. Sign up for our fortnightly Environment newsletter.
