Latest updates

Important information for communities around RAAF Base Williamtown.

• 2024 Ongoing Monitoring Report Factsheet (PDF, 1.15 MB)
• 2024 Ongoing Monitoring Report (PDF, 38 MB)

Investigations and findings

In October 2018, Defence completed investigations into per- and poly- fluoroalkyl substances (PFAS) contamination on and around RAAF Base Williamtown. Defence recognises that PFAS contamination from RAAF Base Williamtown is a significant issue for the local community. Defence is working with with other Commonwealth agencies and the New South Wales (NSW) Government to manage, remediate and monitor PFAS contamination in the area.

The investigations found that PFAS are mostly concentrated in areas where firefighting foams were previously used, stored or disposed. These are called source areas. PFAS can be found in soil and in water flowing through or over the source areas. PFAS moves away from source areas by   surface water flowing in drains and creeks or by groundwater flowing underground through soil and sand.

Six source areas were found on the base where PFAS concentrations required further study or action:

• former fire training area
• Lake Cochran
• the base sewage treatment plant
• trade waste treatment plant
• fire station and fire training pad / foam testing facility
• vehicle refuelling facility transport yard

Further investigations at the demolition of explosive munitions site landfill and north eastern landfill are no longer considered to be a significant source of PFAS.

Human Health Risk Assessment

As part of the investigations, Defence conducted a Human Health Risk Assessment. This assessment measured the PFAS exposure risks to people living, working and undertaking recreational activities within the management area. More detail on Defence’s risk assessment can be found in the Recent reports and factsheets section. 

The NSW Environment Protection Authority (EPA) released precautionary advice for residents within the Williamtown management area to support communities and reduce their exposure to PFAS.

Remediation and management

Defence is working to manage, remediate and monitor PFAS contamination on and around RAAF Base Williamtown. In 2018, remediation works began and are ongoing. From 2018 to 2022, Defence undertook extensive soil, groundwater and surface water remedial works, focusing on the key PFAS source areas. The PFAS Management Area Plan summarises the remedial works, including investigations of possible source areas. 

In October 2022, Defence engaged a panel of local, national and international independent experts to review the effectiveness of remediation actions at RAAF Base Williamtown. The findings of the review were also assessed by experts appointed by the NSW EPA.

The review recommended additional groundwater extractions off the base near Cabbage Tree Road and on the southwest base boundary near the former fire fighter training area. The extractions will decrease the amount of PFAS leaving the base and greatly reduce the PFAS flowing into Fullerton Cove.

A further recommended action for additional surface water treatment on Moors Drain will make the current system more effective. 

The recommendations of the review informed the revised PFAS Management Area Plan, published in December 2023. Defence will provide updates as the plan is implemented.

Groundwater management update 

Defence is installing a pump and treat system along Cabbage Tree Road, as recommended in the PFAS Management Area Plan. This system is designed to prevent significant volumes of contaminated groundwater from entering Leary’s Drain and Fullerton Cove.

The southern area treatment plant is undergoing a major upgrade to support the new system. The upgraded plant will be capable of treating up to 2 million litres of water per day, more than double its current capacity.

The treatment plant will be temporarily inoperable from October 2025 to early 2026 to facilitate the upgrade works. During this period, contaminated groundwater will be captured to process once the upgraded plant is operational.

Since 2018, a water treatment plant located on the western side of the base has been treating groundwater from the former fire fighter training area. Over this time, PFAS concentrations in the groundwater have significantly decreased. By February 2026, the treatment plant will be reconfigured to treat groundwater from the new bore field on the southwest base boundary. This will continue to reduce PFAS at RAAF Base Williamtown and help to decrease the amount of PFAS leaving the base. 

Alternative drinking water supply

Defence is providing water assistance to eligible properties within the Williamtown management area. For further information, please contact the Williamtown Information line during business hours on 1800 011 443 (free-call) or email williamtown.defence@aecom.com.

Ongoing monitoring

Monitoring of PFAS continues on and around RAAF Base Williamtown through sampling of surface water, groundwater, sediment and biota. Monitoring helps Defence understand if PFAS contamination is changing over time.

In December 2023, the PFAS Ongoing Monitoring Plan was updated following consultation with the NSW EPA, NSW Technical Advisory Group and Hunter Water Corporation. The review recommended retaining, removing, and adding sampling locations.

Monitoring results to date have shown that PFAS concentrations in and around the source areas have reduced as a result of remediation. However, the concentrations of PFAS in the management area remain broadly the same. It has taken several decades for PFAS to spread into the management area through groundwater and surface water flows. The remedial works are expected to reduce PFAS from leaving the base, and over time this will contribute to the reduction of PFAS in the management area.

Results are published in an Ongoing Monitoring Report and factsheet. Defence will inform the community if changes to the management approach are required.

Recent reports and factsheets

Reports and factsheets from the PFAS Investigation and Management Program are available to download. All website links and contact details in these documents were correct at the time of publication, but may change over time. To discuss these documents, contact pfas.enquiry@defence.gov.au.

• December 2024 – Community Information Session Factsheet (PDF, 947.49 KB)
• December 2024 – Community Information Session Posters (PDF, 11.5 MB)
• December 2024 – Community Information Session Presentation (PDF, 4.27 MB)
• 2021-2023 Ongoing Monitoring Report with Appendix A-F (PDF, 37.77 MB)
• 2021-2023 Ongoing Monitoring Report Appendix G (PDF, 64.85 MB)
• 2021-2023 Ongoing Monitoring Report Factsheet (PDF, 1.77 MB)
• Revised PFAS Management Area Plan (PDF, 2.9 MB)
• Updated Ongoing Monitoring Plan (PDF, 1.88 MB)
• Revised PFAS Management Area Plan and Updated Ongoing Monitoring Plan Factsheet (PDF, 531.11 KB)
• Ongoing Monitoring and Remediation Update factsheet (PDF 1.3 MB)
• Groundwater Strategy Review Remedial Options report (PDF 57 MB)
• Groundwater Strategy Review Numerical Groundwater Model Update report (PDF 27 MB)
• Addendum to Stage 2C Environmental Investigation: Human Health Risk Assessment - July 2016 report (PDF 289 KB)
• Human Health Risk Assessment factsheet (PDF 670 KB)
• Ecological Risk Assessment factsheet (PDF 1.2 MB)
• Environmental Site Assessment factsheet (PDF 1.04 MB)
• Water Reticulation Project and Payment of Hunter Water's Service Fee and Usage Charges factsheet (PDF 87 KB)

Document archive

The RAAF Base Williamtown document archive contains information about the management of PFAS, including older community presentations, investigation reports, risk assessments and factsheets.

Some archive information has been superseded by the recent reports and factsheets.

Documents Archive - Williamtown (PDF, 277.36 KB)

Last review: 14 October 2025