RAAF Base Pearce (Bullsbrook)

Latest updates

Important information for communities around RAAF Base Pearce.

February 2025 Water Infrastructure Scheme - Community Newsletter (PDF, 793.14 KB)

Questions and Answers factsheet - Scheme Water Infrastructure (PDF, 2.55 MB)

Investigations and findings

In November 2018, Defence completed detailed investigations into per- and poly-fluoroalkyl substances (PFAS) contamination on and around RAAF Base Pearce.

Defence recognises that the PFAS contamination from RAAF Base Pearce is a significant issue for the local community. Defence is committed to working with the Western Australian Government to manage, remediate and monitor PFAS contamination in this 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 in these locations can be found in soil and in water flowing through the source areas. PFAS moves in surface water flowing through drains and creeks or groundwater that flows underground through soil and rock.

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

• fire training area
• former fire training areas
• hangar 93 and foam disposal pit
• grounds maintenance area
• former fuel farm
• RAAF Base Pearce landfill.

Human Health and Ecological Risk Assessment

As part of the investigations, Defence conducted a Human Health and Ecological Risk Assessment. This assessment measured the PFAS exposure risks to people living, working and undertaking recreational activities within the management area and to local plant and animal life.

The investigations found that drinking bore water presents an elevated exposure risk at some properties where PFAS was detected above drinking water guidelines. These properties are being supplied with alternative water.

The investigations also found that drinking bore water presents a low and acceptable exposure risk for the majority of properties within the investigation area.

The assessment also found there was a low risk of exposure when using bore water for activities including showering, washing pets, gardening, and eating locally-grown food including chicken eggs, fruit and vegetables, that are watered with bore water or contaminated groundwater. More details on Defence’s risk assessment can be found in the Human Health and Ecological Risk Assessment factsheet in the Recent reports and factsheets section.

Additional investigations

Defence conducted a PFAS movement assessment that tracks how and where PFAS are moving from source areas and how much PFAS are leaving the base. This study helps determine the best remediation actions to reduce the amount of PFAS leaving RAAF Base Pearce.

The investigations found that PFAS mainly moves off the base through surface water and a series of drains, crossing the southern boundary into Ki-It Monger Brook. A smaller amount of PFAS also moves through surface water over the western boundary and off the base into Ellen Brook. The PFAS then soaks down underground into groundwater, which is why PFAS are found in bores located off the base. This assessment also confirmed that the PFAS contaminated surface soils on the base were the key source areas requiring remediation.

Remediation and management

The aim of remediation is to minimise PFAS leaving the base by focusing on the remediation and management of the source areas. Over time this will contribute to the reduction of PFAS in the management area. Defence has a PFAS Management Area Plan setting out the proposed remedial works and other management actions to manage potential risks presented by PFAS.

As the movement of PFAS from RAAF Base Pearce is mostly through surface water, the remedial work focuses on PFAS in the top layer of soils and other surfaces on the base such as concrete.

Soil remediation

The following provides an update for each of the major PFAS sources identified in the investigations:

Fire training area

The fire training area is located around the air traffic control tower. Investigations have confirmed that this area is the largest source of PFAS leaving the base. The soil in this area contains more than 200 kg of PFAS. A remediation action plan has been prepared to reduce the amount of PFAS entering surface drains located on the site and flowing off the base.

The remediation consists of placing an engineered lining over the contaminated soils, to stop rain water from soaking in, then clean soil is then placed over the lining. This is the best approach for the source area as a network of sensitive underground cables around the air traffic control tower make it unsafe to excavate the soil.

Defence expects that these works will be completed in the coming months.

Former fire training areas

Further studies of the former fire training areas were conducted in 2021 and 2022. The amount of PFAS found was small compared to the fire training area and did not require remediation. No remedial works are proposed for these areas.

Hangar 93 and foam disposal pit

In early 2023, further investigations at hanger 93 and the foam disposal pit found the amount of PFAS in surface water run-off concrete surfaces was low. The concrete surfaces in this source area do not require any remediation or management.

However, PFAS was found within the pipes located in the area. Planned maintenance at the base will repair the pipes and reduce the amount of PFAS impacted water entering the environment. No other remedial works are proposed at this area.

Grounds maintenance area

In April 2021, remediation at the ground maintenance area was completed. Soil containing the highest PFAS concentrations was removed. The area was then sealed with layers of asphalt and concrete. During the remediation work, small quantities of heavily PFAS-impacted soil was removed from RAAF Base Pearce for thermal destruction at a licensed facility. The remaining PFAS-impacted soil was contained and stored ahead of further remediation activities at RAAF Base Pearce. This impacted soil will be placed beneath the engineered lining currently being installed at the fire training area.

Former fuel farm and RAAF Base Pearce landfill

The former fuel farm and RAAF Base Pearce landfill were not found to be major contributors of PFAS movement from the base and did not require further remedial works. No remedial works are proposed at these source areas.

Management actions

Scheme water supply

Defence has engaged Civcon Civil and Project Management Pty Ltd to connect eligible properties in West and South Bullsbrook, with a metered, potable water service from a new West Australian Water Corporation water main.

Construction works have commenced, with anticipated completion by March 2026.

Residents can contact the RAAF Base Pearce Management and Remediation Team on 1800 987 614 or via email at bullsbrook.defence@ghd.com for more information.

Bottled water supply

To register for bottled water, residents within the RAAF Base Pearce management area can complete the online Requests for Bottle Water: Bullsbrook form, or contact the RAAF Base Pearce Investigation and Management Team on 1800 987 614, or via email at bullsbrook.defence@ghd.com. Applications are assessed on a case by case basis.

Ongoing monitoring

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

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

Monitoring results to date have found no significant changes to how PFAS are moving in the management area. However, 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.

Recent reports and factsheets

Detailed reports from the PFAS investigation and management are available for download. Appendices to these reports can be found in the document archive. To discuss these reports, contact pfas.enquiry@defence.gov.au.

• December 2024 Water Infrastructure Scheme - Community Newsletter (PDF, 2.15 MB)
• October 2023 Community Consultative Session Poster (PDF, 5.08 MB)
• October 2023 Community Consultative Session Presentation (PDF, 4.69 MB)
• 2021 Annual Interpretive Report (PDF, 56 MB)
• PFAS Management Area Plan Findings - Factsheet (PDF, 486 KB)
• PFAS Management Area Plan Report (PDF, 14.5 MB)
• Ecological Risk Assessment Findings - Factsheet (PDF, 1 MB)

Document archive

The RAAF Base Pearce document archive contains information that Defence has published 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 - Pearce (PDF, 245.37 KB)

Last review: 25 February 2025