Williamtown RAAF Base is the focus of an investigation into how waste with extremely high firefighting foam contamination levels was discharged into the sewer network through a Rutherford refinery.
Hunter Water took the unprecedented step of disconnecting Australian Waste Oil Refineries from the network on Tuesday after perfluorooctane sulfonate (PFOS) levels up to nearly 400 times the accepted health risk limit were found in samples being discharged to the sewer.
Hunter Water interim CEO Jeremy Bath said a refinery employee told a Hunter Water inspector on February 12 that a “suspicious foam” was fire fighting foam. Sample results confirmed PFOS and perfluorooctanoic acid (PFOA) levels “not dissimilar to the extremely high concentrations detected in parts of the Williamtown investigation area”, Mr Bath said.
The NSW Environment Protection Authority confirmed it contacted the Department of Defence after Hunter Water reported the results.
The EPA has also seized records from Australian Waste Oil Refineries as part of its investigation into the contaminants.
The refinery is licensed to discharge oily water into the sewer network, but not PFOS or PFOA, which are at the centre of the Williamtown RAAF Base contamination scandal after it was revealed contaminants had been “exiting the base” for an unknown period.
Levels up to 1000 times the accepted health risk limit have been detected at the base.
The 116 micrograms per litre recorded in one of the refinery samples is nearly three times higher than the highest known PFOS level recorded on a property just outside Williamtown base.
The base is the focus of investigations because PFOS and PFOA fire fighting foams – widely used by civil and defence firefighters across Australia for decades – have been phased out of use since as early as 2003.
Defence is also the focus because of nearly $1 billion in construction works in preparation for several squadrons of F-35 Joint Strike Fighter jets from late 2018. A 2014 Senate inquiry was told there were only low levels of “sub-surface contaminants” in the redevelopment area.
A Senate inquiry in December was told there was contaminated water within the redevelopment area, which required “dewatering” during excavation below the water table. The water is treated on site.
On Thursday, Mr Bath said Hunter Water was working with the EPA to identify whether the contaminated water “was indeed sourced from the Williamtown area”.
The water authority’s decision to disconnect Australian Waste Oil Refineries was a first that “reflects the seriousness of the non-compliance”, it said in a statement.
Contaminants were found in all samples, including the Farley Wastewater Treatment Plant discharge point at Fishery Point. Although the Fishery Point site was connected to Hunter River there were no immediate concerns about contamination of the river area.
The samples do not affect Hunter Water’s drinking water supply and relate to discharges into the sewer only.
The refinery waste water sample showed a very high level, 116 micrograms per litre, of PFOS and 1.14 micrograms per litre of PFOA.
The Fishery Point discharge point sample showed 1.48 micrograms per litre of PFOS and 0.13 micrograms per litre of PFOA. The accepted health risk limit for PFOS in drinking water is 0.3 micrograms per litre.
Hunter Water advised the EPA of the test results on 22 February. The refinery’s licence to discharge into the sewer is suspended until it can comply with its trade waste agreement and demonstrate controls to keep PFOS and PFOA from entering the system.
There are very few waste treatment plants in NSW that are licensed to treat PFOS and PFOA contaminated water.