More than a third of the water samples taken from rainwater tanks near Orange as part of a citizen survey and tested by an independent laboratory showed lead results above the safe levels in the Australian drinking water guidelines.
Those results are now being re-tested by New South Wales Health in an effort to determine if there is a broader public health risk. NSW Health has not provided any updates about those test results or said whether they confirm the results of the initial testing.
Seventy-one samples from regional properties in central western NSW were analysed in a Sydney laboratory over summer after a number of residents raised concerns about the safety of their household water supplies. Twenty-seven indicated lead levels above the national guidelines.
The concerns were first flagged in response to dust clouds at the Newcrest Cadia goldmine. All samples are from properties located within 15km of the mine which do not have access to town water.
The sampling program was coordinated by the Cadia Community Sustainability Network (CCSN) with the support of Dr Ian Wright, a University of Western Sydney researcher, as part of a community science study into the impacts of the mine on water quality.
In a statement to Guardian Australia, a spokesperson for CCSN said they received results in February that “showed some rainwater tanks seemed to have accumulated heavy metal in the bottom of the tank”.
They then sent the initial samples plus a few more to a different laboratory to be tested again.
“This scoping exercise confirmed the preliminary results,” the statement said. “In total we have now tested 40 residents in the district.
“We have provided the information to the Environmental Protection Agency and NSW Health. NSW Health is planning to retest the pilot study to determine next steps.”
Wright told Guardian Australia the source of the contamination had not been confirmed, but that the lead levels were such that he recommended they seek further testing.
“The results are just gobsmacking,” he said. “There are children drinking this stuff.”
One sample showed lead levels that were 84 times the safe level of 0.01mg/L in the Australian drinking water guidelines.
Two of the samples contained traces of arsenic. A number also contained high levels of copper and zinc, but not above the drinking water guidelines.
Wright said the source of the contamination was a secondary concern.
“The primary question is a human health question,” he said. “Should there be a public health warning issued? Should people be drinking this water?”
Some of the initial 71 samples were of water collected from farm shed roofs, Wright said. Cross-contamination from farming chemicals and machinery had not been ruled out.
NSW Health last week confirmed it had been contacted by residents who were concerned about their water supply and environmental health officers had begun collecting samples of rainwater that serves as private household water supplies, which will be tested at government-approved laboratories.
But it stressed it does not have a role in investigating where the contaminants may have come from, and that management of private water supplies – which includes household rainwater tanks – was the responsibility of the property holder.
Because the results concern private water sources, they will not be released unless a broad public health risk is identified.
The Environmental Protection Agency (EPA) also confirmed it had received a complaint but said it did not comment on ongoing investigations.
Newcrest is also conducting sampling and sending water to be tested at ALS Laboratories, which are providing results directly back to both residents and the mining company.
“Some residents have started receiving their test results directly from the independent experts undertaking the testing,” a spokesperson said. “Tests show drinking water is safe for those who have received their results so far. We are still waiting for the remaining results and analysis of the large scale testing program to come through over the next couple of weeks.”
Earlier, Newcrest said allegations of dust contamination from the mine did not match its own monitoring and stressed that the cause was “currently unknown”.
CCSN said it was hoping to undertake isotope testing of the heavy metals found in the samples, which may help narrow down its origin.
“The CCSN isn’t attributing blame for this contamination until it can be clearly identified where the source has come from,” the spokesperson said. “We hope that NSW Health and the EPA will quickly determine some clear next steps for the community.”
Wright said it was possible that old water pipes and tanks could be the source of some of the metals seen in the samples, particularly copper and zinc. Lead has not been used in water pipes in Australian homes since the 1930s and the use of a lead-based solder on drinking water pipes has been banned since 1989.
