RAAF Base Pearce (Bullsbrook)

Latest updates

Important information for communities around RAAF Base Pearce.

Community Consultative Session Poster – October 2023 (PDF, 5.08 MB)

Community Consultative Session Presentation – October 2023 (PDF, 4.69 MB)

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

On 8 February 2024, a Hazmat alert was issued from WA Department of Fire and Emergency Services advising Bullsbrook residents that wastewater taken from holding ponds located at RAAF Base Pearce was used in firefighting operations. The alert should have identified PFAS chemicals were present in the holding ponds at levels below recreational health based guidelines.

Follow-up PFAS testing was conducted by the WA Department of Fire and Emergency Services. The test results confirm that PFAS levels are below recreational health based guidelines.

Defence continues to work closely with the WA Department of Fire and Emergency Services, the WA Department of Health and the WA Department of Water and Environmental Regulation.

Mail notification for scheme water infrastructure

Residents within the RAAF Base Pearce management area will receive a letter in the mail containing information about connecting to scheme water. The letter will be sent before construction begins.

For more information, please contact the RAAF Base Pearce Management and Remediation Team on 1800 987 614 or bullsbrook.defence@ghd.com.

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 bullsbrook.defence@ghd.com. Applications are assessed on a case by case basis.

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 is mostly concentrated in areas where firefighting foams were previously used, stored or disposed. These are called source areas. The 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:

• Source Area A – Fire training area
• Source Area B – Former fire training areas
• Source Area C – Hangar 93 and foam disposal pit
• Source Area D – Grounds maintenance area
• Source Area J – Former fuel farm, and
• Source Area R – RAAF 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. Drinking bore water at normal consumption rates presents a low and acceptable exposure risk for the majority of properties in 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 detail on Defence’s risk assessments can be found in the Human Health and Ecological Risk Assessment factsheet.

Additional investigations

Defence conducted a Mass Flux Assessment that tracks how and where PFAS is moving from source areas and how much PFAS is 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 base into Ellen Brook. The PFAS then soaks down underground into groundwater, which is why PFAS is found in bores located off the base. This investigation 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 works focuses on PFAS in the top layer of soils and other surfaces such as concrete.

Soil remediation

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

Source Area A - Fire training area

Source Area A is located around the air traffic control tower. Investigations have confirmed that Source Area A 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 for Source Area A, 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. Clean soil is then placed over the lining to a depth of half a metre. This was considered the best approach in this area as a network of sensitive underground cables around the air traffic control tower made it unsafe to excavate the soil.

Defence expects that these works will be completed in 2024.

Source Area B - Former fire training areas

Further studies of Source Area B were conducted in 2021 and 2022. The amount of PFAS found was small compared to Source Area A and did not require remediation. No remedial works are proposed for Source Area B.

Source Area C - Hangar 93 and foam disposal pit

In early 2023, further investigations at Source Area C found the amount of PFAS in surface water run-off concrete surfaces was low. The concrete surfaces in Source Area C do not require any remediation or management.

However, PFAS was found within the ageing pipes located in Source Area C. 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 Source Area C.

Source Area D - Grounds maintenance area

In April 2021, remediation at Source Area D was completed. Soil containing the highest PFAS concentrations was removed. The area was then sealed with layers of asphalt and concrete. During the Source Area D remediation work, small quantities of heavily PFAS impacted soil from Source Area D was removed and placed into safe storage.

Source Area J and Source Area R - Former fuel farm and RAAF Base Pearce landfill

Source Areas J and R 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 Source Areas J and R.

Groundwater remediation

Groundwater remediation will not be used because the investigations suggest that surface water run-off is the key source of PFAS leaving the base. This targeted approach of addressing contaminated surface water will contribute to the reduction of PFAS concentrations in and around the base.

Management actions

Scheme water supply

Defence is working with the WA Water Corporation to connect properties in the RAAF Base Pearce PFAS Management Area to the town water supply. Defence will fund construction of the pipeline as well as funding water usage and rates for 6 years.

Design of the pipeline is well advanced and construction of the pipeline mains is scheduled to commence in early 2024 in West Bullsbrook and mid to late 2024 in South Bullsbrook.

Residents within the management area will receive a letter in the mail containing information about the access required to their properties. The letter will be sent before construction begins.

A community walk in session will be held after this mail-out to give residents a chance to ask questions about the connection process.

Prior to this, residents can contact the RAAF Base Pearce Management and Remediation Team on 1800 987 614 or bullsbrook.defence@ghd.com for more information.

Bottled water supply

At a community meeting on 16 December 2022, Defence was asked to supply bottled water to the community until the new scheme water system is connected.

Defence already provides bottled water to community members where PFAS has been found in their bore water. However, Defence understands some people are worried that their bore water might become contaminated with PFAS in the future.

To help with these concerns, Defence is offering bottled water to people living in the management area on a case-by-case basis.

This does not mean the risk with PFAS contamination has changed. Defence is confident that its ongoing monitoring program will identify any changes in PFAS contamination in the local area.

Residents who would like to register for bottled water, can complete the Requests for Bottle Water: Bullsbrook form, or contact the RAAF Base Pearce Investigation and Management Team on 1800 987 614, or bullsbrook.defence@ghd.com.

Ongoing monitoring

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

The results are published in an Ongoing Monitoring Interpretative 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 is 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.

• Community Information Session Presentation - Dec 2022 (PDF 302 KB)
• Community Information Session Posters - Dec 2022 (PDF 7.7 MB)
• Community Information Session - Water Infrastructure FAQs - Dec 2022 (PDF 687 KB)
• 2020 Annual Interpretive Report - Nov 2021 report (PDF 56 MB)
• PFAS Management Area Plan Findings - Jul 2019 factsheet (PDF 486 KB)
• PFAS Management Area Plan - Jul 2019 report (PDF 14.5 MB)
• Ecological Risk Assessment Findings - Nov 2018 factsheet (PDF 1 MB)
• Ecological Risk Assessment - Dec 2018 report (PDF 3 MB)
• Detailed Site Investigation - Jul 2018 report (PDF 686 KB)

Document archive

The RAAF Base Pearce document archive contains information that Defence has published about the management of PFAS. This includes:

• older community presentations,
• investigation reports,
• risk assessments and
• factsheets.

Some archived information has been superseded by recent reports and factsheets.

Documents Archive - Pearce (PDF, 245.15 KB)

Last review: 3 November 2023