Latest updates

​Important information for communities around RAAF Base Tindal.

RAAF Base Tindal Interpretive Report - September 2023 (PDF, 83.08 MB)

Remediation and monitoring update - factsheet – August 2023 (PDF, 1.13 MB)

Community consultation session posters – August 2023 (PDF, 2.47 MB)

Community consultation session presentation – August 2023 (PDF, 2.73 MB)

On Tuesday 29 August 2023, Defence held 2 community walk-in information sessions to provide the Katherine community with an update on remediation and management activities and the ongoing monitoring of per- and poly- fluoroalkyl substances (PFAS) on and around RAAF Base Tindal.

The second event was attended by the Honourable Matt Thistlethwaite MP, Assistant Minister for Defence, where he met with the local community to hear their concerns.

For questions relating to the past event, email pfas.tindal@truenorthcomm.com.au or call 1800 316 813.

Cossack area monitoring

Recent sampling within the Cossack area has found first time detections of PFAS. At some properties the results were above the health-based guideline values for PFAS and alternative water supplies are being arranged. For further information and support, please contact the Tindal Information Line on 1800 316 813 or email pfas.tindal@truenorthcomm.com.au.

Investigations and findings

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

Defence recognises that the PFAS contamination from RAAF Base Tindal is a significant issue for the local community. Defence is committed to working with the Northern Territory State Government to manage, remediate and monitor PFAS contamination in the 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.

Two source areas were identified on the base where PFAS was found in soil or groundwater at concentrations that required further assessment or action. These were:

  • Fire training area
  • Fire station area

Human Health and Ecological 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.

This assessment found that drinking bore water presents an elevated exposure risk at some properties where PFAS was detected above drinking water guidelines. These properties have been contacted and are being supplied with alternative water.

Under a typical consumption scenario, an elevated exposure risk was identified for young children eating poultry eggs (for example from chickens). An elevated exposure risk was also identified for adults if they are in the upper consumption scenario within Zone 1. The location of Zone 1 is shown on a map on page 170 of the PFAS Management Area Plan.

The Human Health Risk Assessment also found there was a low and acceptable exposure risk when using bore water for activities including:

  • showering
  • washing pets
  • gardening

and eating locally-grown food watered with bore water or contaminated groundwater including:

  • fruit and vegetables
  • home grown meat such as chicken, duck, sheep, cattle, goat and pig.

More detail on Defence’s risk assessments can be found in the Human Health Risk Assessment factsheet and the Ecological Risk Assessment factsheet.

Based on the findings of Defence’s investigations, the Northern Territory Environment Protection Authority advises eating bush food should be avoided in some areas. It is safe to eat some plants and animals from the Katherine region. However, the amount that is eaten should be limited because some species contain higher levels of PFAS. Bushfoods in Katherine fact sheet (PDF 103.4 KB)

It is safe to eat wild caught fish from the Daly River and outer waterways. However, eating fish, shellfish and crustaceans from Katherine River (between Donkey Camp Weir and Daly River) and Tindal Creek should be limited. There is a very low risk for tourists and visitors who may occasionally eat fish from the affected areas. For more detailed precautionary advice, please refer to the Northern Territory Department of Health’s Fishing in the Katherine area fact sheet (PDF 202.8 KB).

Defence’s ecological risk assessment found there was a medium exposure risk to ecology within Tindal Creek. All other habitat zones were found to have a low exposure risk, or a very low exposure risk to the ecology.

Additional investigations

Defence also 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 Tindal.

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. The main source areas at RAAF Base Tindal are the Fire Training Area and Fire Station Area.

Over time this remediation will reduce the amount 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.

Soil remediation - update

The following information provides an update for each of the major PFAS source areas identified in the investigations:

  • Fire training area and fire station area

Investigations have confirmed that the fire training area and fire station area are the largest sources of PFAS leaving the base. The soil in both source areas contain more than 400 kg of PFAS.

Remediation works for the Fire Training Area and the Fire Station Area, to reduce PFAS discharges to surface drains on the site and to groundwater commenced in 2022 and are currently continuing. The remediation includes a process called soil stabilisation. The process removes PFAS-impacted soil and treats it with a natural product. This makes the PFAS stick to the product within the soil and stops it from moving when it rains. The treated soil is then placed back and covered with a clean layer of topsoil to prevent erosion. If the soil has PFAS concentrations that are too high to treat effectively, that soil will be sent interstate for disposal at a thermal destruction facility.

Defence expects that these works will be completed in late 2023.

Water remediation of source areas

Since 2019, Defence has operated an additional 2 groundwater treatment plants on RAAF Base Tindal to remove PFAS from groundwater and to reduce the amount of PFAS moving off Base. These plants have treated over 2.51 billion litres of PFAS contaminated groundwater to date. Summaries of the Water Treatment Plant sampling results are listed on this page under the Recent reports and factsheets section.

Managing Katherine’s impacted water supply

PFAS contaminated groundwater has impacted the groundwater used for drinking water in the Katherine area. To address this, Defence is working with the NT Power and Water Corporation to treat PFAS impacted water before it enters the town water supply.

In 2017, Defence and the Northern Territory Power and Water Corporation built a PFAS water treatment plant in Katherine to filter PFAS from bore water. The plant has been designed to treat up to 1 million litres of bore water per day. The bore water quality is carefully monitored by the Northern Territory Power and Water Corporation.

To secure a long-term water supply for Katherine, Defence has agreed to fund the Northern Territory Power and Water Corporation for the construction and operation of a new permanent PFAS treatment plant in Katherine. The new plant will treat up to 10 million litres of water per day.

In areas where residents rely on bore water that has been impacted by PFAS, Defence is providing residents with an alternative water supply such as bottled water (an interim solution), or rain water tanks.

Ongoing monitoring

Monitoring of PFAS continues through surface water, groundwater and aquatic biota. 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.

Results from the recent sampling conducted during the dry season returned first time detections and detections above health based guideline values of PFAS at some properties within the Cossack area. As these are first time detections further samples and analysis will be conducted. Impacted property owners are being supported by Defence with the supply of alternative drinking water.

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.

Water Treatment Plant reports

Reports from the management of Water Treatment Plants.

Water Treatment Plant Sampling Results Katherine Power and Water Corporation (PDF, 2.62 MB)

Water Treatment Plant Sampling Results RAAF Base Tindal Fire Training Area (PDF, 1.47 MB)

Water Treatment Plant Sampling Results RAAF Base Tindal Fire Station Area (PDF, 1.35 MB)

Document archive

The RAAF Base Tindal 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 - Tindal (PDF, 298.44 KB)

Last review: 31 July 2023