Blue Mountains PFAS investigation

WaterNSW is conducting its own rigorous testing of water sources in the Blue Mountains’ catchment – including soil and water sampling – as part of its investigation into the source and causes of the elevated PFAS results.

The Australian Drinking Water Guidelines only apply to water that has been treated for human consumption. They do not apply to raw, untreated water – such as that sampled by the Herald. All water provided for human consumption remains safe.

Testing foam in Greaves Creek, as also reported in media, is less reliable; it is well-recognised that foam is likely to provide inflated results on overall concentration levels.

The extensive WaterNSW sampling program is occurring alongside work with multiple agencies to explore historical land use activities such as firefighting, which may have involved PFAS.

The outcome of the investigation will inform the next steps to further mitigate the risk, for example isolating water run-off from contaminated areas of the catchment, and/or modifying infrastructure at the extraction and treatment point.

WaterNSW has already taken action to move Medlow Dam and Greaves Creek Dam offline as a precaution, while we investigate possible new localised PFAS contamination sources or causes nearby.

The Sydney Water Cascades Water Filtration Plant is being supplied by the Cascades catchment and can be supplemented by the Fish River water supply scheme in the Oberon catchment, which had close to zero detections of PFAS in the raw water – if needed.

WaterNSW will keep the community informed as the investigation progresses and work closely with NSW Health and Sydney Water to ensure drinking water remains safe.