28/8/24: WaterNSW disconnects Medlow Dam in the Blue Mountains as investigations continue into presence of ‘forever chemicals’ in water
Authorities have shut a small dam in the Blue Mountains after tests found traces of cancer-linked PFAS “forever chemicals”, and are now investigating the source of the contamination.
WaterNSW has confirmed that Medlow Dam returned elevated traces of PFAS in tests that were carried out in recent days.
It’s the only one among the five dams in the Blue Mountains dam network to have returned “slightly elevated PFAS levels”.
The tests in untreated dam water were carried out after Sydney Water recently detected chemicals in the Blue Mountains at the Cascade Dam water filtration plants at Blackheath and Katoomba.
Sources have told the ABC the levels found in the untreated water at Medlow Dam were 0.09 micrograms per litre (µg/L).
The Australian safe level for PFOS and PFHxS, which are both PFAS types, combined is 0.07 micrograms per litre (µg/L).
Dams to be subject to ongoing investigation and monitoring
In a statement on its website, WaterNSW said “this dam does not supply raw water directly but as a precautionary measure has been disconnected from supply while further investigations are conducted.
“The small Blue Mountains dam network is a series of five dams which supply Cascade water filtration plant.
“These dams will be subject to ongoing, targeted investigation and monitoring.
“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.”
The ABC understands authorities have no idea at this stage where the chemicals have come from and are looking for the original source, including examining the creeks that flow into the dam and investigating what uses may have been taking place around it .
PFAS are man-made chemicals that were used in firefighting foam because of their resistance to heat, stains, grease and water.
However, they don’t break down fully in the environment and can travel long distances in water, according to WaterNSW.
WaterNSW also says on its website that the PFAS detected by Sydney Water in the Cascade water filtration plant were within safe drinking water guidelines.
“All treated water samples were below these levels and NSW Health and Sydney Water have confirmed the water supplied from the Cascade water filtration plant to local communities meets the Australian Drinking Water Guidelines and is safe to consume.”