It's yet another mystery, along with how long PFAS have been in the Blue Mountains water supply. Both Water NSW and Sydney Water did not test for PFAS in the region prior to mid-2024.

The Medlow Dam in the Blue Mountains has been disconnected by WaterNSW as a "precautionary measure" as investigations continue into the presence of PFAS, known as "forever chemicals", in the water.

PFAS was detected in Medlow Dam in the Blue Mountains earlier this year. Picture: Water NSW The upgrade is estimated to cost $3.5 million, according to the ABC.

Yucaipa has a recreational jewel in the local mountains. Big Bear Lake is just 49 miles from Yucaipa. Last month, the lake ...