Lake Mulwala result reached 36 times PFOS guideline
PFAS chemicals were detected repeatedly in parts of the Murray River in Victoria between 2017 and 2026, including a Lake Mulwala reading on 13 July 2023 that reached 0.29µg/L for PFOS.
That Lake Mulwala result was 36 times the current PFOS drinking water guideline. Nine PFAS chemicals were detected at the same time at Lake Mulwala, Yarrawonga.
Friends of the Earth Australia said Freedom of Information material showed Victoria’s highest PFAS pollution event in a drinking water supply occurred at Lake Mulwala on 13 July 2023.
North East Water recorded PFAS chemicals 19 times in the Murray River between August 2017 and November 2024. Nine of those detections occurred at Lake Mulwala on 13 July 2023.
Lower Murray Water found 26 detections
Lower Murray Water started testing for PFAS in drinking water supplies in December 2024. Between December 2024 and February 2026, it recorded 26 detections across eight locations.
Those results averaged 5% to 9% of health guideline levels. However, 60% of the detections were above the ANZECC PFOS Biota Screening Threshold of 0.0005µg/L.
The detections indicate that about 250km of the Murray River from Koondrook to Mildura could be affected by PFOS above ecological guideline levels.
Testing in New South Wales has been limited. Balranald Shire Council took part in the 2024 NSW Health PFAS Screening Program and returned some positive results.
Meanwhile, SA Water tested a couple of Murray River locations in May 2025 and April 2026. Those samples were negative, but the detection level used was 20 times higher than similar Lower Murray Water monitoring in Victoria.
EPA Victoria also detected PFOS in floodwater sampling in late 2022. At Echuca, PFOS measured 0.0006µg/L on 31 October 2022.
The Campaspe River at Echuca returned 0.001µg/L on 8 November 2022. Friends of the Earth Australia said the cause of the 13 July 2023 Lake Mulwala event was never investigated.
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