Whim Creek copper mine faces questions over possible Pilbara river pollution
The problem appears to have been made worse by the torrential downpour that came with Tropical Cyclone Veronica in March when more than 500 millimetres of rain soaked the area over two days.
Four months after the deluge, the Whim Creek Copper Project, about 100 kilometres south of Port Hedland, is under investigation and has been issued with an Environmental Protection Notice.
Inspections by the Department of Water and Environmental Regulation (DWER) showed continued seepage from the mine into the nearby Balla Balla river system and surrounding environment posed a serious pollution risk.
Earlier water testing in 2014, 2016 and 2018 indicated heavy metals above guideline levels in ponds, leach pads and bores, as well as hypersaline and highly acidic groundwater.
The latest inspection also indicated acidic groundwater, as well as concentrations of heavy metals such as aluminium, cadmium, cobalt, copper, lead, nickel and zinc.
The levels were significantly above Australian and New Zealand guidelines for fresh and marine water quality, livestock drinking-water quality guidelines and human drinking-water guidelines.
The EPA notice said there was increased environmental risk, including to the immediate groundwater aquifer should the process-water and environmental ponds continue to operate as they are now.
Department inspectors are concerned about the wellbeing of aquatic life, such as barramundi.
The Whim Creek Copper Project is owned by VentureX Resources Limited, but outsourced to Black Rock Minerals for copper production.
It has been in "care and maintenance" mode for several years.
Mine operators have been told to cease all "active discharges" and engage an environmental consultant to manage the problem.
Mine owner 'inherited the contamination'
VentureX confirmed that following Cyclone Veronica the environmental pond, which was built to the standard for a 1:100 year rainfall event, overflowed into the environment.
It said it was managing the contamination issue and meeting all the requirements outlined in the latest EPA notice, issued in July.
A consultant has been engaged to test water in the river system and results are pending.
VentureX said it inherited the contamination when it bought the mine in 2009.
Balla Balla Station is downstream from the copper mine and its cattle drink from several wells in the area.
Testing water for livestock
Bettini Beef owner and Balla Balla Station leaseholder Mark Bettini runs about 1,600 cattle on the property, previously known as Mallina.
"We were informed when we first purchased Mallina that there was possible contamination at a site right adjacent to the copper mine, but at that stage it was only 'possible'," Mr Bettini said.
Mr Bettini lost some of his cattle during the cyclone and is concerned about further losses.
"I am concerned for the cattle [and staff] and that perhaps the pollution has spread further," he said.
"We've got a few wells down the Balla Balla Creek in close proximity to that mine, so we're going to be testing the water and making sure it's suitable for livestock.
"If not, we'll be asking the operators of the mine to do something about it."
Mr Bettini said he had not been told by the department or the mine operators about potential water pollution issues and only found out about it recently.
"[Probably] because it hasn't been operating for the past couple of years," he said.
"I think that probably Cyclone Veronica with the high rainfall has really magnified the problem.
"First and foremost we'll make sure the cattle are all right, that they've got [good] water."
He said he may need extra water resources to cover his cattle's needs.
'Very serious questions': Professor
Environmental engineer and copper-mine specialist Associate Professor Gavin Mudd, from the Royal Melbourne Institute of Technology (RMIT), said the present investigation needed to show the flow path — where the potential contamination started from — where it moved to, and where it ended up.
"We don't know much about the problem yet, but it raises very serious questions about the potential for contaminants and pollutants to escape that mine site and get out into the environment," Professor Mudd said.
Concerned locals recently had the water tested by a lab in Perth which showed copper levels of 3.5 milligrams per litre.
"Normally for freshwater ecosystems, the sort of concentrations we'd like to see for things like copper, or zinc would be about .001 or .002 milligrams per litre or parts per million," Professor Mudd said.
"A lot of freshwater ecosystems would have about that, so any concentrations above that and you can start to cause significant impacts to aquatic biodiversity."
Professor Mudd said there had been similar issues at Australian copper mines, the most infamous one being the Lady Annie copper mine disaster in Queensland in 2014 when heavy rain caused the collapse of critical infrastructure.
"From my understanding there are some significant issues that need to be looked at for this site," Professor Mudd said.
"The investigation really needs to address how much of a source the mine could potentially be, what the pathway of any contamination migrating or travelling away from the mine site could be, and then also how we clean that up," he said.
"They are the questions that we really need to get good answers to and make sure that's done very publicly and transparently."
The department has advised the ABC that the Environmental Protection Notice has been appealed by one party.