Environmental regulators and NSW politicians have traded barbs over delayed and inadequate testing for so-called "forever chemicals" in drinking water supplies.
PFAS, or per- and plufluoroalkyl substances, accumulate in water, soil and living organisms and have been linked to cancer, immune suppression and developmental issues.
Their discovery in substantial quantities in raw water supplies west of Sydney sparked community concern and testing across major catchments.
In a tense exchange on Friday, the NSW Environment Protection Authority faced repeated questions on their perceived inaction despite longstanding awareness of contamination.
"Why has the EPA not, over many years, strongly urged all of the water utilities to test their drinking water," inquiry chair Cate Faehrmann said.
Agency bosses denied blame and pointed fingers elsewhere.
"The regulation here is quite clear ... NSW Health is the regulator for drinking water standards," chief executive Tony Chappell said.
Criticism deepened as the inquiry turned to the Belubula River in central western NSW, where contaminated foam was found at levels "thousands of times above what is safe."
Despite beginning tests in May, the EPA admitted it had yet to test aquatic life.
"It's now December... you haven't got to fish yet," Ms Faehrmann said.
Mr Chappell attributed delays to flooding but conceded "that sampling team does a whole lot of stuff around the state."
Calls for public safety measures, like warning signs, were met with resistance.
"Wouldn't it be wise to put signs down saying, 'Don't swim in this river; don't eat fish from this river?" Ms Faehrmann said.
Water tests did not identify any "acute" risks, Mr Chappell responded.
Water scientist Ian Wright was scathing of the inaction, pointing to his team's findings of dangerous PFAS chemical levels in wildlife.
"I've got a PhD student who has tested the livers of dead platypus," Dr Wright said.
"Those samples had enormous levels of (forever chemicals)."
A co-ordinated, transparent and clearly communicated plan for water testing was sorely needed, the committee was told.
"We are far from that with our largest drinking water utilities blindly aware of PFAS contaminating in their Blue Mountains supply, perhaps for decades," Dr Wright said.
Fire and Rescue Commissioner Jeremy Fewtrell also fronted the inquiry, acknowledging land use changes, such as converting contaminated sites into residential areas, could expose vulnerable people to forever chemicals.
Some contaminated sites were sold before robust testing protocols were established.
Firefighters exposed to forever chemicals have faced delays in cancer screenings due to cost concerns, with testing expected to begin early 2025.
PFAS are a group of more than 14,000 synthetic chemicals, used since the 1950s in products like firefighting foams, non-stick cookware and water-resistant materials.