Centennial Coal mine faces EPA clean-up notice over salinity spikes
Polluted water from coal mining near Lithgow is polluting a major river in the Sydney drinking water catchment, the environmental watchdog has found.
The NSW Environmental Protection Authority has issued a clean-up notice to Centennial Coal’s Springvale mine after detecting large increases in the salinity of the Coxs River downstream of the discharge point used by the mine.
The Coxs River, a highly protected river that flows 60 to 70 kilometers through the Blue Mountains World Heritage Area to the Warragamba Dam, is affected by several coal mines as well as the Mount Piper power station and the now closed Wallerawang site.
An EPA spokesperson said Centennial Coal is needed to reduce the total volume of water discharged into the environment. The cleanup notice, issued on January 23, has phased deadlines from now until May.
“NSW EPA recognizes the community’s concerns about the environmental impacts of coal mining in the region and is committed to using its regulatory powers to minimize these impacts,” the spokesman said.
Contaminated mine water was stored at Cooks Dam and released into Wangcol Creek at discharge point LDP001, which Western Sydney University aquatic scientist Professor Ian Wright described as “the worst regulated waste discharge” he knows of.
A common measure of salinity is electrical conductivity, which the EPA said exceeded Australian rules on two dates, once reaching as high as 4270 microsiemens per centimeter (μS/cm), according to the coal company’s own monitoring.
“The clear streams of the Blue Mountains are below 50 μS/cm, when you get some human settlement it’s a few hundred, and 4000 is a huge number,” Wright explained.
“I’ve been looking at this for years; there’s a salinity plume extending from this area to the Coxs River on its journey towards Warragamba Dam.”
Wright said there is no legal limit on the salinity of discharge into streams, but he hopes the EPA will regulate it in the future. He said the agency’s description of the increase in salinity as a pollution event was a “change in tone” as the problem had previously been ignored.
Wright said Warragamba was the saltiest of Sydney’s drinking water reservoirs, but was within safe limits and far better than many towns in Australia. His main concern was the health of the Coxs River, habitat for platypuses and other plants and animals.
Wright also called for tighter controls on certain pollutants such as zinc and nickel, describing the current limits as a “permit to pollute.” Centennial, for example, reported that its last discharge contained 377 micrograms of nickel per liter of water. That’s below the EPA license limit of 500 micrograms, but well above the 10 microgram threshold at which it becomes hazardous to aquatic life, Wright said.
Jacqueline Mills of the Nature Conservancy Council said the EPA had taken reports from the public, including the Lithgow Environmental Group, seriously and that the clean-up notice was “a step in the right direction”.
Underground coal mining has drained swamps and caused subsidence, threatening the unique rock pagodas in the nearby Stone Gardens area, he noted.
“The location of these coal mines in the Lithgow area, which is an extremely environmentally sensitive area, is regrettable,” Mills said.
Centennial Coal did not respond to requests for comment.
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Caitlin Fitzsimmons is the environment and climate correspondent for The Sydney Morning Herald. He was previously a social affairs reporter and Money editor.Connect via email.
