Blue Mountains
PFAS investigation and raw water testing results
Report a hazard - phone: 1800 061 069
WaterNSW head office
1PSQ, Level 14, 169 Macquarie Street Parramatta, NSW 2150
Contact us:
P: 1300 662 077
E: enquiries@waternsw.com.au
Postal address
WaterNSW
PO Box 398, Parramatta, NSW 2124
Warragamba Dam visitor centre
P: 02 4774 4433
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What might remediation involve?
Once the nature and extent of contamination is suitably characterised, a detailed remediation action plan will be prepared. Options may include disposal of contaminated materials or containment.
When will information be made available regarding the investigation?
We will continue to publish raw water monitoring data from the Blue Mountains dams monthly. We anticipate a report to be made available in mid-2025.
Have you ever closed dams like this before?
We take dams offline for operational reasons routinely as required.
We modify system configuration often in Greater Sydney for various reasons. WaterNSW dams can be isolated for maintenance and that is what makes the system quite resilient and flexible, allowing us to maintain water supply as conditions change.
For example, we’ve taken Warragamba Dam offline during large inflow events (or bushfires) to manage water quality.
Results of samples taken 20 November 2024 – Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water but is supplied to Sydney Water for treatment at the Cascades Water Filtration Plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (1m depth) | 0.0011 | 0.0262 | 0.0363 | 0.0625 |
Medlow Dam (1m depth) | 0.0019 | 0.0481 | 0.0627 | 0.111 |
Upper Cascade Dam (1m depth) | <0.0005 | 0.0066 | 0.0089 | 0.0155 |
Middle Cascade (1m depth) | <0.0005 | 0.0027 | 0.0033 | 0.006 |
Lower Cascade (1m depth) | <0.0005 | 0.0026 | 0.0031 | 0.0057 |
Source water inlet to Cascade water filtration plant | <0.0005 | 0.0071 | 0.0093 | 0.0164 |
Raw water Oberon pipeline to Cascades at Leura | <0.0005 | <0.0005 | 0.0004 | 0.0004 |
Results of samples taken 6 November 2024 – Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water but is supplied to Sydney Water for treatment at the Cascades Water Filtration Plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (1m depth) | 0.001 | 0.0271 | 0.0437 | 0.0708 |
Medlow Dam (1m depth) | 0.0019 | 0.0529 | 0.0729 | 0.126 |
Upper Cascade Dam (1m depth) | <0.0005 | 0.0078 | 0.0115 | 0.0193 |
Middle Cascade (1m depth) | <0.0005 | 0.0033 | 0.0042 | 0.0075 |
Lower Cascade (1m depth) | <0.0005 | 0.0025 | 0.0033 | 0.0058 |
Source water inlet to Cascade water filtration plant | <0.0005 | 0.0074 | 0.0113 | 0.0187 |
Raw water Oberon pipeline to Cascades at Leura | <0.0005 | <0.0005 | <0.0003 | <0.0003 |
Results of samples taken 23 October 2024 – Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water but is supplied to Sydney Water for treatment at the Cascades Water Filtration Plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (1m depth) | 0.001 | 0.0283 | 0.0393 | 0.0676 |
Medlow Dam (1m depth) | 0.0018 | 0.047 | 0.0669 | 0.114 |
Upper Cascade Dam (1m depth) | <0.0005 | 0.0073 | 0.0098 | 0.0171 |
Middle Cascade (1m depth) | <0.0005 | 0.0034 | 0.0055 | 0.0089 |
Lower Cascade (1m depth) | <0.0005 | 0.0024 | 0.003 | 0.0054 |
Source water inlet to Cascade water filtration plant | <0.0005 | 0.0075 | 0.0098 | 0.0173 |
Raw water Oberon pipeline to Cascades at Leura | <0.0005 | <0.0005 | <0.0003 | <0.0003 |
Results of samples taken 9 October 2024 – Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water but is supplied to Sydney Water for treatment at the Cascades Water Filtration Plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (1m depth) | 0.0009 | 0.0265 | 0.0409 | 0.0674 |
Medlow Dam (1m depth) | 0.0019 | 0.0605 | 0.0602 | 0.121 |
Upper Cascade Dam (1m depth) | <0.0005 | 0.0087 | 0.0101 | 0.0188 |
Middle Cascade (1m depth) | <0.0005 | 0.0029 | 0.0037 | 0.0066 |
Lower Cascade (1m depth) | <0.0005 | 0.0022 | 0.003 | 0.0052 |
Raw water Oberon pipeline to Cascades at Leura | <0.0005 | <0.0005 | <0.0003 | <0.0003 |
Results of samples taken 27 September 2024 – Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water, but is supplied to Sydney Water for treatment at the Cascades Water Filtration Plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (1m depth) | 0.0009 | 0.0319 | 0.0351 | 0.0670 |
Medlow Dam (1m depth) | 0.0014 | 0.0450 | 0.0690 | 0.114 |
Upper Cascade Dam (1m depth) | <0.0005 | 0.0098 | 0.0136 | 0.0234 |
Middle Cascade (1m depth) | <0.0005 | 0.0034 | 0.0046 | 0.0080 |
Lower Cascade (1m depth) | <0.0005 | 0.0025 | 0.0034 | 0.0059 |
Results of samples taken 10 and 17-19 September 2024 – Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water, but is supplied to Sydney Water for treatment at the Cascades Water Filtration Plant.
For drinking water results, please visit Sydney Water.
Water source | Sample date | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|---|
Greaves Creek Dam (1m depth) | 10/9/24 | 0.0008 | 0.0229 | 0.0291 | 0.0520 |
Medlow Dam (1m depth) | 18/9/24 | 0.0016 | 0.0524 | 0.0614 | 0.114 |
Upper Cascade Dam (1m depth) | 17/9/24 | <0.0005 | 0.008 | 0.0125 | 0.0205 |
Middle Cascade (1m depth) | 18/9/24 | <0.0005 | 0.0050 | 0.0053 | 0.0103 |
Lower Cascade (1m depth) | 10/9/24 | <0.0005 | 0.0023 | 0.0026 | 0.0049 |
Raw water supplied to Cascade water filtration plant | 17/9/24 | <0.0005 | 0.0082 | 0.0122 | 0.0204 |
Raw water from Oberon Dam supplied to Duckmaloi water filtration plant | 19/9/24 | <0.0005 | <0.0005 | 0.0006 | 0.0006 |
Results of samples taken 3 September 2024 - Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water, but is supplied to Sydney Water for treatment at the Cascades water treatment plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (1m depth) | 0.0009 | 0.0264 | 0.0324 | 0.0588 |
Medlow Dam (1m depth) | 0.0017 | 0.0485 | 0.0608 | 0.109 |
Upper Cascade Dam (1m depth) | <0.0005 | 0.0098 | 0.0127 | 0.0225 |
Middle Cascade (surface) | <0.0005 | 0.0051 | 0.0402 | 0.0453 |
Lower Cascade (1m depth) | <0.0005 | 0.0023 | 0.0027 | 0.005 |
Raw water supplied to Cascade water filtration plant | <0.0005 | 0.0113 | 0.0124 | 0.0237 |
Results of samples taken 16 August 2024 - Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water, but is supplied to Sydney Water for treatment at the Cascades water treatment plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (surface) | 0.001 | 0.0275 | 0.0315 | 0.059 |
Medlow Dam (surface) | 0.0015 | 0.0456 | 0.0488 | 0.0944 |
Upper Cascade Dam (surface) | <0.0005 | 0.0098 | 0.0272 | 0.037 |
Middle Cascade (surface) | <0.0005 | 0.0035 | 0.0042 | 0.0077 |
Lower Cascade (surface) | <0.0005 | 0.002 | 0.0022 | 0.0042 |
Raw water supplied to Cascade water filtration plant | <0.0005 | 0.0092 | 0.0111 | 0.0203 |
Raw water from Oberon Dam supplied to Duckmaloi water filtration plant | <0.0005 | <0.0005 | 0.0006 | 0.0006 |
Results of samples taken 31 July 2024 - Raw (untreated) water
These results reflect the untreated, raw source water in WaterNSW’s dams. This water is not supplied directly for use as drinking water, but is supplied to Sydney Water for treatment at the Cascades water treatment plant.
For drinking water results, please visit Sydney Water.
Water source | PFOA (µg/L) | PFHxS (µg/L) | PFOS (µg/L) | PFHxS + PFOS (µg/L) |
---|---|---|---|---|
Greaves Creek Dam (surface) | 0.0009 | 0.0244 | 0.0335 | 0.0579 |
Medlow Dam (surface) | 0.0014 | 0.0398 | 0.0548 | 0.0946 |
Upper Cascade Dam (surface) | 0.0005 | 0.0098 | 0.014 | 0.0238 |
Lower Cascade Dam (surface) | <0.0005 | 0.0019 | 0.003 | 0.0049 |
Raw water supplied to Cascade water filtration plant | <0.0005 | 0.0109 | 0.0136 | 0.0245 |
Raw water from Oberon Dam supplied to Duckmaloi water filtration plant | <0.0005 | <0.0005 | <0.0003 | <0.0008 |
Is Sydney’s water safe to drink?
Sydney Water and NSW Health have advised Sydney’s drinking water is compliant with the existing Australian Drinking Water Guidelines (ADWG) and is safe to drink. For NSW Government information on PFAS visit www.nsw.gov.au/pfas.
For most people, drinking water is sourced from well-protected, often pristine catchments, and water goes through multiple levels of testing to ensure it is safe and meets the Australian Drinking Water Guidelines.
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.
How often will you be carrying out PFAS testing in WaterNSW dams?
WaterNSW is carrying out fortnightly testing of the Blue Mountains System, and monthly testing of Greater Sydney storage dams. Results are published monthly. 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.
How is WaterNSW communicating the results of its testing?
The results of the testing are available here on our website. Dedicated pages have been created for Blue Mountains System and Greater Sydney storage dam results. Result data is published monthly.
Why are different depths tested and reported?
We test at different depths and consistently measure and report at the offtake depth, to be representative of the raw water being supplied via our pipelines to the various water filtration plants. We are working to consistently measure and report the most accurate and useful data with Sydney Water and NSW Health and to keep the community informed.
Has WaterNSW transferred any additional water from Oberon Dam to the Blue Mountains dams?
Yes, transfers commenced 30 September 2024.
How Is WaterNSW responding to the proposed new drinking water guidelines?
WaterNSW will work with the NSW Government on implementation of the revised guideline levels as required.
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