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Environment Protection Authority

EPA tests further for PFAS in Williamtown drain

Media release: 9 September 2016

The NSW Environment Protection Authority (EPA) has received results from early August testing for per- and poly fluorinated alkyl substances (PFAS) in surface water and what appears to be naturally formed foam in a drain at Nelson Bay Road, Williamtown.

The results for combined perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were identified at levels of 2 micrograms per litre in the drain’s surface water. Significantly higher levels were detected within the foam with the samples showing PFOS/PFHxS levels at nearly 500 micrograms per litre.

The high PFAS results in the foam do not present a risk to human health so long as people follow the precautionary advice to avoid incidental ingestion of ground and surface water. See the fact sheet on foam and chemical contamination in waterways for more information.

It is important to note that as the foam collapses, the chemicals re-enter the surrounding water and become diluted, back to the lower levels.

NSW EPA Director North Branch, Adam Gilligan, said that the high PFAS results were not indicative of levels in the surrounding environment but reflected the foam’s characteristic of collecting and concentrating chemicals, including chemical contaminants.

“Understanding the way that foams behave helps us to understand the significance of these results,” Mr Gilligan said.

The Williamtown Contamination Expert Panel has advised the NSW EPA that the foam is unlikely to have been formed by the PFAS in the surrounding water, as PFAS concentrations there were at least 1000 times lower than is needed to produce foam.

The foam is considered to have formed naturally, as a filmy by-product of decaying natural material such as leaves, which foamed up due to wind or heavy rain, on the water’s surface. The foam has then collected and concentrated the PFAS chemicals from the surrounding water, creating a significant difference between levels in the foam and in the water.

The EPA continues to seek a commitment from Defence to pursue and implement solutions to minimise discharges of PFAS contaminants migrating from the RAAF Base, so that the PFAS chemicals are prevented from flowing through Williamtown’s waterways.


  • Community members experiencing anxiety or concern should call the support line on 0417 494 576 from 8am - 4pm Monday to Friday or 1800 011 511 after hours.
  • For more information about PFAS contamination in Williamtown visit



Contact: Public Affairs

Page last updated: 12 September 2016