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Environment Protection Authority

EPA tests PFOS levels in Moors Drain Williamtown

Media release: 1 August 2016

The NSW Environment Protection Authority (EPA) has received results from recent testing of surface water and a foam residue in Moors Drain, Williamtown, following community concerns.

EPA Regional Director North Branch, Adam Gilligan, said the results from the EPA’s sampling in mid-July 2016 identified perfluorooctane sulfonate (PFOS) levels of 2.39 micrograms per litre in the drain’s surface water. This is consistent with the range of samples taken by the EPA in Moors Drain since late 2015, however considerably higher levels of PFOS were detected within the foam residue.

“The levels of PFOS detected in the foam residue measured at 90 micrograms per litre, but we do not believe that these limits are indicative of PFOS levels in the surrounding environment.

“The foam residue found in Moors Drain was likely caused by the presence of a foaming agent such as a cleaning detergent. It appears that, as the foam has formed, it has pulled PFOS from the water so the concentration of PFOS is higher in the foam residue than in the water,” Mr Gilligan said.

“The EPA will refer the results of our testing to the Williamtown Expert panel for further consideration and raise the issue with Defence for further testing around Moors Drain to ensure that PFOS levels return to the lower levels found in surface water in the drain once the foam dissipates,” Mr Gilligan said.

“We would like to reiterate that PFOS chemicals do not produce foam at the concentrations identified around Williamtown RAAF Base. The PFOS concentration measured in the foam residue in Moors Drain was at least 1000 times lower than the concentrations needed to produce foam.

“Defence has advised the EPA that it has stringent controls on the management of groundwater from building works occurring on base, including passing all exposed groundwater through its treatment system on-site.

“The EPA has spoken to Defence again about its expectations that construction works on the Williamtown RAAF Base do not increase the amount of contaminated surface water leaving the base,” he said.

For more information about the NSW EPA's state-wide PFAS investigation program, visit

Contact: Public Affairs

Page last updated: 01 August 2016