A gold mine near Orange in the New South Wales Central West has confirmed its waste storage facilities are leaking.
The leak has sparked fears of broadscale groundwater contamination in the farmland surrounding the Cadia gold mine, which is owned by the Newmont Corporation.
Guy Fitzhardinge runs beef cattle on his property, which flanks the southern tip of Cadia’s boundary, and shares ground and surface water sources with the mine.
He does not yet know if the water on his property is affected, but he is concerned it could impact his operation because producers must declare livestock exposure to contaminants.
“I was only recently made aware of the extent of the problem,” Dr Fitzhardinge said.
“To have some contamination in my beef would be absolutely disastrous, personally, but it would also reflect badly on Australia in terms of its beef exports.”
Since 2016 Cadia’s annual environmental reports have shown that multiple bores on the site contain water that matches the chemical make-up of the mine’s waste.
“The most recent annual review for 2023 concludes any seepage from the tailings storage facilities (TSF) is localised to the immediate TSF area and is contained,” a spokesperson said in a statement.
“[The seepage] does not have an impact on downstream groundwater water receptors.”
‘Major review is needed’
Western Sydney University associate professor Ian Wright has been researching the impact of Cadia’s operations on water sources.
Last year he discovered dust from the mine was likely polluting residential rainwater tanks.
Dr Wright is among the expert and community voices calling on the Environment Protection Authority (EPA) to tighten groundwater regulation in the mine’s operating licence, which will soon be up for renewal.
“There’s a whole cavalcade of contaminants that are present in groundwater resources in and around the area,” he said
“The big ones I’ve seen are arsenic, zinc, manganese and sulphates.
“A major review of [Cadia’s licence] is needed.”
‘Critical importance’
EPA executive director of operations Jason Gordon confirmed the watchdog had identified groundwater monitoring as a “priority” in its current review of the mine’s licence.
An EPA spokesperson said no exceedences were found in 2022 and 2023 monitoring.
But Dr Wright said Cadia’s licence did not specify pollutant limits for groundwater or require the monitoring of any material in waste storage.
“This information is of critical importance,” Dr Wright said.
“How can neighbours know what pollutants that are present in Cadia’s land and water might be escaping into surrounding properties?”
Cadia is not required to monitor bores off the site, which would allow the company to compare water quality in the area.
“There seems to be a blind spot,” Dr Wright said.
‘Slow and persistent’
Hydrologist Steven Pells said pollution in groundwater moved through the system the way sugar dissolved “in your tea”.
He said pollution plumes were almost impossible to see from above the ground and that it was difficult to determine their size or course.
Dr Pells said contaminants could stick to soil particles and cause more contamination.
“It’s a slow and persistent process and very difficult to clean up,” Dr Pells said.
He said groundwater contamination usually had implications for surrounding river systems.
“If I were a landholder in the vicinity of the mine, I would be concerned that a slow process had been unlocked,” Dr Pells said.
He said the mine needed to provide more evidence to back its claim that the pollution was contained, which he said would be difficult to guarantee.
“I think it is factually correct to state [the pollution] will move,” Dr Pells said.
Operation at stake
Dr Fitzhardinge said running a sustainable operation was a top priority for him.
“We try to run a clean and green operation,” he said.
“Where you get dust or noise, you can mitigate that.
“But once something is in the groundwater, you’ve got it for life.”
Dr Fitzhardinge wants to see more scrutiny from regulators.
“All the monitoring at the moment is done by the mine itself,” he said.
“That’s a bit like leaving a block of cheese in charge of a mouse.”
