A major investigation has detected high-level contamination of highly toxic PFAS chemicals in water might be the result of incidents from over 30 years ago.

Angry residents in a popular tourist location want free tests for cancer-causing PFAS 'forever chemicals' in their blood after a major investigation revealed they had been drinking from a contaminated water supply for decades.
Per- and polyfluoroalkyl substances (PFAS) are a group of 15,000 highly toxic, synthetically produced chemicals resistant to heat, stains and grease, dubbed "forever chemicals" because of their inability to break down.
High-level contamination was detected in the drinking water catchment serving 30,000 people in the Blue Mountains in NSW in mid-2024.
PFAS levels were shockingly found to be around an incredible 300 times higher than Sydney's main drinking water source but they still met Australian guidelines for safe drinking water.
An eight-month WaterNSW investigation released on Friday zeroed in on three potential sources of contamination dating as far back as 33 years ago.
Two separate motor vehicle accident sites on the Great Western Highway in 1992 and then in 2002 near the Medlow Bath township, and the Medlow Bath Rural Fire Brigade station were identified as possible sources of contamination in the Adams Creek and Medlow catchments.
Residents to pursue class action
John Dee, a veteran environmental activist, described the fallout as an "Erin Brockovich-level scandal".
He's the leader a group called Stop PFAS that will sue the NSW government and Sydney Water to get free PFAS blood testing for local residents as well as seeking compensation for those affected.
"People in the Blue Mountains have been drinking toxic tap water for 32 years," he stated.

Results of tests paid for by some residents have found PFAS in the bloodstream nearly 50 times the level considered safe by the chemicals manufacturer 3M.
While the value of individual blood tests is debated among scientists, exposure to PFAS increases the risk of testicular and kidney cancer, affecting the immune system and causing developmental damage in children.
What happens next?
Medlow Dam and Greaves Creek Dam, of which Adams Creek is a tributary, will remain disconnected from the water supply system, WaterNSW said.
The dams will only return when permanent mitigation measures are in place.
Steep terrain, potential PFAS spread over a wide geographical region and extensive disturbance of high-value ecological habitat are all flagged as barriers to remediation.
A spokesperson for Sydney Water said it would work with other agencies to ensure it met the proposed Australian Drinking Water Guidelines.
Is it safe to drink water from these areas?
Health authorities say current drinking water meets existing guidelines and is safe to drink.
But the report did not quantify the current rate of PFAS discharge from potential source areas in surface water and groundwater, nor the total mass of PFAS previously discharged.
Risks to human health and the environment from exposure to PFAS at the source areas have also not been quantified.
After community pressure, Sydney Water installed a $3.4 million mobile PFAS treatment plant at the Blue Mountains catchment in January.
The National Health and Medical Research Council drafted new drinking water guidelines in October, reducing the benchmark for the PFOA group of chemicals.
Don't put your family's health at risk and consider installing effective PFAS water filtration solutions for your home as soon as possible.