Fish River scheme

PFAS testing results
Learn more about the NSW Government response to PFAS at nsw.gov.au/pfas

Related pages:  PFAS |  Blue Mountains| Greater Sydney | Regional NSW

The Fish River water supply scheme draws water from Oberon Dam and Duckmaloi Weir to provide to Oberon and Lithgow councils for domestic and industry use, to about 230 properties along its route and to Wallerawang and Mount Piper power stations. It also supplements supplies in the upper Blue Mountains.

The scheme is unique as the only water supply scheme in eastern Australia to transfer western flowing water east of the Great Dividing Range, mostly by gravity, enabled by 236 kilometres of pipelines and a tunnel under the Great Dividing Range.

From May 2025, sampling results for the Fish River scheme will be published quarterly.

Treated water results

These results reflect water treated for drinking, supplied as part of the Fish River scheme.

May 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)		PFBS
(µg/L)
Treated water at Duckmaloi Water Treatment Plant 20/5/2025 <0.0005 <0.0005 <0.0003 <0.0003<0.0005

March 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Treated water at Duckmaloi Water Treatment Plant 12/03/2025 <0.0005 <0.0005 <0.0003 <0.0003

February 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Treated water at Duckmaloi Water Treatment Plant 13/02/2025 <0.0005 <0.0005 <0.0003 <0.0003

January 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Treated water at Duckmaloi Water Treatment Plant 16/01/2025 <0.0005 <0.0005 <0.0003 <0.0003

December 2024 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Treated water at Duckmaloi Water Treatment Plant 11/12/2024 <0.0005 <0.0005 <0.0003 <0.0003

November 2024 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Treated water at Duckmaloi Water Treatment Plant 21/11/2024 <0.0005 <0.0005 <0.0003 <0.0003

October 2024 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Treated water at Duckmaloi Water Treatment Plant 29/10/2024 <0.0005 <0.0005 <0.0003 <0.0003

Raw water results

These results reflect the untreated, raw source water. This water is not supplied directly for use as drinking water but is supplied for treatment as drinking water.

May 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)		PFBS
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant 20/5/2025 <0.0005 <0.0005 <0.0003 <0.0003 <0.0005
Raw water Oberon pipeline to Cascades at Leura Pipeline offline during sampling.

March 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant 12/03/2025 <0.0005 <0.0005 <0.0003 <0.0003
Raw water Oberon pipeline to Cascades at Leura 14/03/2025 <0.0005 <0.0005 <0.0003 <0.0003

February 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant 13/02/2025 <0.0005 <0.0005 <0.0003 <0.0003
Raw water Oberon pipeline to Cascades at Leura 19/02/2025 <0.0005 <0.0005 <0.0003 <0.0003

January 2025 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant 16/01/2025 <0.0005 <0.0005 <0.0003 <0.0003
Raw water Oberon pipeline to Cascades at Leura 22/01/2025 <0.0005 <0.0005 <0.0003 <0.0003

December 2024 sampling
Location Sample DatePFOA
(µg/L)		PFHxS
(µg/L)		 PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant 11/12/2024 <0.0005 <0.0005 <0.0003 <0.0003
Raw water Oberon pipeline to Cascades at Leura 18/12/2024 <0.0005 <0.0005 <0.0003 <0.0003

November 2024 sampling
Location Sample Date PFOA
(µg/L)		 PFHxS
(µg/L)		 PFOS
(µg/L)		 PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant 21/11/2024 <0.0005 <0.0005 <0.0003 <0.0003
Raw water Oberon pipeline to Cascades at Leura 20/11/2024 <0.0005 <0.0005 0.0004 0.0004

October 2024 sampling
LocationSample DatePFOA
(µg/L)		PFHxS
(µg/L)		PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant29/10/2024<0.0005<0.0005<0.0003<0.0003
Raw water Oberon pipeline to Cascades at Leura23/10/2024<0.0005<0.0005<0.0003<0.0003
Raw water Oberon pipeline to Cascades at Leura9/10/24<0.0005<0.0005<0.0003<0.0003
Raw water Oberon pipeline to Cascades at Leura3/10/240.0007<0.0005<0.0003<0.0003
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant2/10/24<0.0005<0.0005<0.0003<0.0003

September 2024 sampling
SampleSample DatePFOA
(µg/L)		PFHxS
(µg/L)		PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant19/9/24<0.0005<0.00050.00060.0006

August 2024 sampling
SampleSample DatePFOA
(µg/L)		PFHxS
(µg/L)		PFOS
(µg/L)		PFHxS + PFOS
(µg/L)
Raw water from Oberon Dam supplied to Duckmaloi Treatment Plant16/8/24<0.0005<0.00050.00060.0006

Frequently asked questions

Does WaterNSW test for PFAS?

WaterNSW monitors many water quality parameters over a very large area across the Greater Sydney catchment and dams. This includes extensive water testing and real time monitoring 24/7. Each month thousands of data points are collected and evaluated continually for the management of source water quality.

When testing for PFAS, WaterNSW takes a targeted, risk-based approach, based on based on expert advice from NSW Health and other authorities such as the Environment Protection Authority.

How do you sample and test?

WaterNSW has highly-experienced field staff and expert water quality scientists undertaking sampling and analysis.

Sampling, collection and transport are conducted by highly-skilled professionals with strict protocols in place. Our partner labs have detailed steps that must be followed to ensure accurate analysis of our samples. This is essential to ensure that samples are not contaminated by everyday items that contain PFAS such as outdoor clothing, makeup, and sunscreen. Our monitoring teams are ISO 9001 certified, and all partner laboratories are NATA accredited.

WaterNSW is a highly regulated organisation and subject to extensive external regulatory oversight. This ensures WaterNSW’s work in this field is meticulous and meets the highest standard. WaterNSW has an extensive water quality monitoring program and is one of the leading agencies when it comes to water quality monitoring in NSW.

All samples are subject to quality control and assurances processes. Should any part of the process not meet these requirements, results are not considered valid and are not reported on our website.

How often are results for PFAS testing in WaterNSW dams published? Where can I read them?

Results are published monthly for the Blue Mountains and Greater Sydney. Results of testing in our regional NSW dams and Fish River Scheme are published quarterly. Water goes through multiple levels of testing and treatment to ensure it is safe and meets the Australian Drinking Water Guidelines before it comes out of your taps.

Has WaterNSW transferred any additional water from Oberon Dam to the Blue Mountains dams?

Yes, transfers commenced 30 September 2024.

Related links

NSW Government PFAS informationnsw.gov.au/pfas >

Sydney Water PFAS information
View at sydneywater.com.au >

NSW Health PFAS information
View at health.nsw.gov.au >

WaterNSW acknowledges the traditional custodians of the lands and waters on which we work and pay our respects to all elders past, present and emerging. Learn more