Testing in 2023 and 2024 detected levels below the new US maximum,Chant said.

The water filtration plant at North Richmond is about 13 kilometres upstream from the Royal Australian Air Force base,which is considered a potential source of PFAS contamination for the area.

North Richmond is theonly site where Sydney Water tests for the contaminants. Sydney Water’s website states:“We are not currently monitoring drinking water supplies for PFAS except at North Richmond.”

A Sydney Water spokeswoman said in a statement:“There are no known PFAS hotspots in our drinking water catchments.”

The most comprehensive data comes from a federally fundedUniversity of Queensland study published in 2011, which sampled 34 locations across the country. Localised surveillance in recent years confirmed the chemicals were still turning up in some of the same locations they were first found in 2011,in some instances at higher concentrations.

In December 2023,the World Health Organisation’s International Agency for Research on Cancer (IARC) upgraded its classification of PFOA from“possibly carcinogenic” to “carcinogenic to humans”.

IARC’s decision was based on “sufficient evidence it can cause cancer in lab animals and strong evidence that it has some of the key properties of a carcinogen in people who are exposed to it”.

Chant confirmed that NSW authorities had adopted the new classification of PFOA as “carcinogenic”,but said the evidence was not conclusive.

“We are exposed every day to a variety of different chemicals. We are exposed to radiation,we are exposed to all sorts of things that impact our health including particulate pollution,” Chant said.

Chant said proportionate efforts were under way to lower exposure,including the phasing out of the use of these chemicals worldwide and reviews of drinking water standards.

The National Health and Medical Research Council – which developed Australia’s Drinking Water Guidelines – is reviewing its guidelines for PFAS in the wake of the overseas developments.

Chant said that depending on the outcome of this review,“We may well move to the same levels[as the US].”

The two chemicals in the spotlight are part of a broader family of per- and polyfluoroalkyl substances (PFAS),best known as “forever chemicals” because they never break down in the environment and linger for years in the human body.

This masthead contacted all 23 affected Australian drinking water providers and they responded that their water is safe because levels detected fall within Australia’s drinking water guidelines. Many exceed the new US safety thresholds,which are based on recent scientific evidence showing forever chemicals are more dangerous than previously understood.

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