PFAS

In June 2025 the National Health and Medical Research Council (NHMRC) released updated Australian Drinking Water guidelines which outline new, lower recommended values of PFAS in drinking water. The NSW Government has confirmed that all NSW public drinking water supplies – across metropolitan and regional areas - currently meet the new Australian Drinking Water Guidelines and is safe to drink.

Learn more at nsw.gov.au/pfas

PFAS are emerging, man made contaminants that are persistent in the environment. They are commonly found in and around populated areas throughout Australia and internationally, because of their widespread use in everyday consumer products.

Testing and investigations

Blue Mountains

Greater Sydney

Fish River scheme

Regional NSW

What are PFAS?

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals. They've been widely used in industrial and consumer products since the 1950s, as they are effective at resisting heat, stains, grease and water.

They can be found in everyday products like carpets, non-stick cookware, food packaging, cosmetics, sunscreen, clothing, pesticides and fertilisers. Some PFAS have also been used in fire-fighting foams.

Their resistance to heat, stains, grease and water also means that they don't break down fully in the environment and can travel long distances in water.

Increased environmental levels of PFAS have been found near some industrial sites, airports, defence bases and other locations in Australia.

PFAS chemicals are not added to drinking water but can be present in water at very low concentrations due to contamination from various external sources in the environment and everyday consumer products.

Read more about PFAS at the Water Services Association of Australia website or the Environment Protection Authority website.

PFAS and drinking water

All water supplied as drinking water in Australia must meet the Australian Drinking Water Guidelines. In June 2025 the National Health and Medical Research Council (NHMRC) released updated Australian Drinking Water guidelines which outline new, lower recommended values of PFAS in drinking water.

Importantly, the NSW Government has confirmed that all NSW public drinking water supplies – across metropolitan and regional areas - currently meet the new Australian Drinking Water Guidelines. Read more at nsw.gov.au/pfas

WaterNSW supplies untreated water, sometimes described as 'raw water' or 'source water', to Sydney Water and some councils around NSW, who then treat and supply the water to your tap. The Fish River Water Supply System near Oberon is an exception. Learn more about WaterNSW's role.

For most people, drinking water is sourced from well-protected, often pristine catchments, or it goes through multiple barrier treatment processes.

Australian Drinking Water Guidelines apply to water treated for human consumption and do not apply to raw water, or source water, before it’s treated, and found in the dams.

The Australian Drinking Water Guidelines set strict health-based guideline limits for numerous contaminants, including PFAS among many other things.

The Australian Drinking Water Guidelines and the continual expert review process are part of our rigorous, independent and scientific system that helps keep drinking water safe.

How is WaterNSW responding?

PFAS were detected by Sydney Water on the outlet of the Cascade Water Filtration Plant in June 2024. All treated water samples were below the levels required by the existing Australian Drinking Water Guidelines, and NSW Health and Sydney Water have confirmed the water supplied from the Cascade Water Filtration Plant to local communities meets the existing Australian Drinking Water Guidelines and is safe to consume. Learn more about Sydney Water's findings and monitoring.

WaterNSW is working on short and longer term solutions to bring that system into line with the rest of Sydney’s water supply.

WaterNSW:

Conducted subsequent investigative testing of untreated, raw water targeting the five Blue Mountains dams in July, which supply the Cascade Water Filtration Plant, with elevated levels identified in Medlow Dam.
Disconnected Medlow Dam and Greaves Creek Dam from supply as a precautionary measure.
Commenced targeted PFAS-related investigations so any risks continue to be managed appropriately.
Commenced transfers of water from Oberon Dam to the Blue Mountains dams on 30 September 2024 to provide additional water and blend supply. This short to medium-term response has the potential to bring the Cascades Water Filtration Plant to within the proposed new Australian Drinking Water Guideline values, if they are adopted, by mid-2025.
Is publishing raw water monitoring data from the Blue Mountains dams, monthly.

Frequently asked questions

Is Sydney's water safe to drink?

The NSW Government has advised Sydney’s drinking water is compliant with Australian Drinking Water Guidelines and is safe to drink. For NSW Government information on PFAS visit nsw.gov.au/pfas.

WaterNSW supplies untreated water, sometimes described as 'raw water' or 'source water', to Sydney Water and councils around NSW who then treat and supply the water to your tap. The Fish River Water Supply System is an exception. This process of testing and treating the ‘source water’ we supply is rigorous, ensuring that drinking water that comes out of your tap is safe and meets the Australian Drinking Water Guidelines

The thorough scientific process for setting the guidelines helps maintain high quality drinking water for all Australians. Australia has some of the highest quality drinking water compared to anywhere else in the world.

How is the Sydney drinking water catchment monitored?

Sydney’s drinking water catchment is 16,000 square kilometres – about half the size of Belgium.

Water quality monitoring across the catchment follows a targeted, risk-based approach to help ensure the treated water supplied for consumption meets the existing Australian Drinking Water Guidelines. Consistent with the government regulatory frameworks, the approach is based on expert advice from NSW Health and other authorities such as the Environment Protection Authority.

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.