Restrictions on chemicals in drinking water may be difficult for some to swallow

National drinking water guidelines for potentially cancer-causing chemicals should be tightened, but some communities and experts want them to go even further.

The draft benchmarks, based on new science about the health risks of PFAS, were released Monday following an increase in detections of the long-lived chemicals in water sources.

But the National Health and Medical Research Council was forced to immediately defend its “very conservative” proposed guidelines, which for one group of PFAS are 50 times higher than the new US limits.

The “perfectly reasonable” Australian proposal, although not as stringent as the US restrictions, which begin in 2029, is within the ranges proposed by other regulators, according to RMIT University chemistry professor Oliver Jones.

“I’m sure some will think these guidelines are influenced by ‘big chemistry,’” he said.

“But remember, the people who make the rules also need to drink the water, just like their families.”

The strengthened recommendations are based on lifetime risk that warrants further investigation.

But they have been criticized for not covering a broader range of PFAS chemicals.

More than 15,000 PFAS chemicals have been created and are used widely, from firefighting foam to nonstick pots and pans.

Australia’s proposal was “much less stringent” than those put forward by Europe, the US and Canada, UNSW Water Research Laboratory managing director Denis O’Carroll said.

“Much more work needs to be done to map PFAS contamination in Australian water sources and the government needs to take a number of actions urgently,” Professor O’Carroll said.

Water quality expert Stuart Hahn warned that upgrading wastewater treatment plants to new standards would be costly for consumers.

“Increasing costs of drinking water will hit small regional communities the hardest,” said the head of the University of Sydney’s School of Civil Engineering.

The first upgrade could affect 80,000 people living in the pristine World Heritage-listed Blue Mountains region, where some dams were shut down in August to curb newly discovered PFAS contamination.

Despite current regulations, levels of the PFOS subgroup of chemicals in drinking water supplied to thousands of homes are nearly three times the new limit.

Sydney Water on Monday admitted its Cascade filtration plant would need to be upgraded to meet new standards as part of a wider project costing between $60 million and $100 million.

This project may take two to three years.

Officials stressed that the water remains safe to drink.

But the case highlighted the need for regular testing of all Australian drinking water sources, Stop PFAS founder John Dee said.

“How many other communities will face the same problem as the Blue Mountains when other water companies start testing their drinking water for PFAS?” – he said.

All other water supplies in Sydney are under new restrictions and the NSW Government hopes test results from all regional water supplies will be published by the end of 2024.

TasWater on Monday said nearly 2,000 recent tests of every raw water catchment it uses found no PFAS.

If adopted, the guidelines would lower the benchmark for the PFOA group of chemicals from 560 nanograms per liter to 200 nanograms per liter, based on carcinogenic effects.

One nanogram is about one drop in 20 Olympic-sized swimming pools.

The PFOS limit dropped sharply to four nanograms per liter, while new limits were set for the PFHxS and PFBS groups.

Each level is based on the lifetime risk of exposure associated with drinking two liters of alcohol per day, according to the National Health and Medical Research Council.

Advisory committee member David Cunliffe said the recommendations were “very conservative”.