National drinking water guidelines for potentially carcinogenic chemicals will be tightened following increasing discoveries of PFAS in water sources.
Draft benchmarks based on emerging science on health risks were released on Monday, immediately welcomed by Australian experts and the water industry.
But the National Health and Medical Research Council has been forced to defend its proposed guidelines, calling themselves “very conservative,” to avoid reaching the near-zero level established in the United States.
PFAS substances are a group of more than 15,000 chemicals that are resistant to heat, stains, grease and water, earning the nickname “forever chemicals” due to their inability to break down.
Their use has varied widely, from firefighting foam to nonstick pots and pans.
Recent discoveries of elevated amounts of chemicals in some New South Wales water supplies have led to dam closures and community concern, particularly in the Blue Mountains.
PFAS substances are a group of more than 15,000 chemicals that are resistant to heat, stains, grease and water, earning the nickname “forever chemicals” due to their inability to break down. Above, drinking water stock photo
Water quality expert Stuart Khan said Australians can continue to have confidence that national guidelines incorporate the latest, robust science to support safe drinking water.
But he warned that improvements to treatment plants to meet lower standards will come at a cost to consumers.
“In some cases, advanced water treatment processes may be necessary and the cost of these advances will necessarily be passed on to customers’ bills,” said the director of the School of Civil Engineering at the University of Sydney.
“The rising cost of drinking water will hit smaller regional communities the hardest.”
Australian Water Services Association chief executive Adam Lovell said the industry supported the thorough scientific process used to establish the guidelines.
“For most of us, drinking water comes from well-protected, often pristine, watersheds or goes through multiple barrier treatment processes,” he said.
The guidelines, if adopted, would lower the benchmark for the PFOA group of chemicals from 560 to 200 nanograms per liter based on their carcinogenic effects.
One nanogram is approximately equivalent to one drop in 20 Olympic swimming pools.
Water quality expert Stuart Khan warned new guidelines would come with a financial cost
Guidelines on PFOS would decrease from 70 to four nanograms per liter based on bone marrow effects, while new guidelines were established for the PFHxS and PFBS groups due to thyroid concerns.
Each level is based on lifetime exposure risks, the research council stated.
“It’s not about the concentration that is toxic at this time, but rather that you need to drink above these levels over a lifetime to have what we consider at this time to be toxic effects,” said the council’s executive director, Steve Wesselingh.
The new guidelines were based on animal studies after the council’s water quality advisory committee considered there were not enough high-quality human studies available.
Giving more weight to those human studies and legal differences led the U.S. Environmental Protection Agency to adopt near-zero standards in April, said advisory committee member David Cunliffe.
“Our guidelines are very conservative,” he said.
“We always err on the side of caution.”
The standards were not to be seen as an approval measure, but rather as a trigger for water authorities to investigate potential sources of contamination.
They are likely to be finalized in April after public consultation began on Monday.