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Fire Fighting Foam (PFAS) Investigation

What are PFAS?

Per- and poly-fluoroalkyl substances (PFAS), also known as perfluorinated chemicals, are a class of manufactured chemicals that have been used since the 1950s to make commercial and industrial products that resist heat, stains, grease and water, including ‘Scotchguard’, non-stick cookware products and fire-fighting foams. There are many types of PFAS, with the best known examples being perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonate acid (PFHxS).

These chemicals have been identified worldwide as emerging contaminants. Some PFAS have been shown to be toxic to some animals, and because they don’t break down in the environment, have potential to bioaccumulate in plants and animals. National health authorities advise that there is currently no consistent evidence that exposure to PFAS causes adverse health effects. However, because these compounds are persistent, human exposure should be minimised as a precaution.

A PFAS interagency working group (PFASIWG) was established in April 2016 to implement a co-ordinated approach to the investigation and response to potential environmental and health issues related to PFAS. Membership comprises representatives from NT government agencies including the NT Department of Health (DoH); NT Department of Primary Industry and Resources; Northern Territory Environment Protection Authority (NT EPA); Darwin International Airport; and the Commonwealth Departments of Defence and Infrastructure and AirServices Australia

The PFASIWG developed and coordinates implementation of the Northern Territory PFAS Legacy Site Investigation Strategy. This strategy guides an expanded investigation into the presence of PFAS in water and soils at locations where they may have been used in large quantities in the NT, including airports, firefighting training facilities and some industrial sites.

Water Testing in the Katherine Region

PWC has developed an integrated water management strategy for the Katherine water supply. This strategy aims to minimise the amount of PFAS in the water supply.

Monitoring results for the Katherine water supply system, which is sampled weekly, are updated monthly on the PWC web site. PWC have reported that four individual samples in the Katherine public water supply have exceeded health based guidance values since PFAS testing began in November 2016. However the average level is less than the guidance value. These fluctuations are likely to continue.

The Federal Chief Medical Officer and Northern Territory Chief Health Officer have advised that the Katherine town water supply is safe to drink and that there is minimal risk to human health posed by short-term exceedances of the tolerable daily intake for drinking water. 

While the NT Government works with the Department of Defence on a long term solution, including new water sources and advanced water treatment technologies the Northern Territory Government has announced water conservation measures for Katherine, to help reduce overall demand and keep the use of ground water to a minimum. The measures will commence 21 August 2017:

  • Odd numbered properties are permitted to irrigate Monday, Wednesday and Saturday from 6pm – 8am
  • Even numbered properties are permitted to irrigate Tuesday, Thursday and Sunday from 6pm – 8am
  • No watering of hard surfaces 
  • Hand held watering via a bucket or watering can is permitted at any time.


To support these compulsory water conservation measures, Power and Water is rolling out the Living Water Smart program in Katherine.

Additionally the Department of Defence will provide an interim water treatment plant to reduce the amount of (PFAS) in the Katherine town water supply. This water treatment plant will be operational in the final quarter of 2017 and will act as an interim measure to assist in reducing PFAS concentrations in the bore water component of the Katherine town water supply.


Rapid and Ludmilla Creeks

A joint investigation by the DoH and NT EPA in February last year identified the presence of PFAS in the waters of Rapid Creek and Ludmilla Creek. 

Drinking water from Rapid Creek or Ludmilla Creek is not advised due to fluctuating levels of microorganisms, and it is understood that groundwater is not extracted for human consumption. The Northern Territory Department of Health issued a precautionary health advisory in May 2016 regarding the consumption of aquatic foods such as fish and shellfish from these creeks until further testing is complete.

The levels of PFAS chemicals have been measured in various species of aquatic foods from Ludmilla Creek and Rapid Creek. The first phase of testing indicated that PFAS are present in molluscs; and resulted in a second phase of testing of a different range of aquatic foods.

Results for the initial (Phase 1) investigation were released in 2016. The Phase 1 investigation report has since been revised to reflect new health based guidance values published by Food Standards Australia New Zealand in April this year. The Phase 2 investigation report  also reflects the new national guidance values. 

The Minister for Health announced the release of the reports on 27 July 2017. The reports indicate that:

* PFAS chemicals are present in aquatic foods like long bums, periwinkles, crustaceans and fish; although those foods can be eaten without exceeding the recommended total dietary intake. 

* Fish and other aquatic species are highly nutritious foods and a source of protein, omega-3 fatty acids, vitamins and minerals and should be eaten as part of a varied and balanced diet. However overconsumption of fish and other seafood is not recommended because it may lead to potentially higher intake of harmful substances such as mercury.

* The presence of PFAS in Rapid Creek and Ludmilla Creek does not alter the recommended maximum fish consumption to avoid excessive mercury intake (an average of 3, 150 gram serves of these foods per week for an adult and 2 serves for an expectant or pregnant woman or a child). People are reminded to adhere to the fish consumption guidelines published by Food Standards Australia New Zealand. 

The studies increase the understanding of PFAS in Darwin waterways and assist investigations including the ongoing Detailed Site Investigation for RAAF Base Darwin being undertaken by the Australian Department of Defence. Imminent finalisation of draft ANZECC interim water quality trigger levels for PFAS will be important in assessing the potential for any ecological impacts from PFAS in Rapid Creek and Ludmilla Creek.

Defence Bases

In September 2015 the Department of Defence and NSW Environment Protection Authority released information about the discovery of chemical contamination from PFAS in surface water, ground water and fish, near the Williamtown RAAF base in the Hunter Valley. Further contamination has been identified around the Oakey RAAF base in Queensland and the former Country Fire Authority (CFA) Training College in Fiskville, Victoria.

The Department of Defence has carried out preliminary sampling to characterise the presence of PFAS compounds near RAAF Base Darwin, RAAF Base Tindal and Robertson Barracks. See information on the preliminary sampling program.

RAAF Base Darwin and RAAF Base Tindal are prioritised and investigation work commenced in March 2017. The detailed environmental investigation for Robertson barracks is due to commence in mid 2017.

The NT Government is represented at the project control group that is overseeing Defence detailed environmental investigations in the NT and is working with Defence to ensure the investigation process is comprehensive, efficient and transparent.

Between 23-25 November 2016, Defence hosted community ‘walk in’ consultation sessions at RAAF Bases Tindal and Darwin and at Robertson Barracks to provide further information to interested community members about the response of PFAS contamination at and from Defence sites.
A second round of community consultation sessions were held on 22 March in Darwin and Katherine on 12 April 2017. 

A third round community consultation sessions were held in late June 2017 in Darwin and Katherine.

Further information about the Defence National PFAS environmental investigation program, including the Northern Territory Investigation sites,  can be found on the Defence website and via the Defence national hotline: 1800 365 414.

New FSANZ Health Based Guidance Values

Food Standards Australia New Zealand (FSANZ) was contracted by the Australian Department of Health in June 2016 to develop new national health based guidance values for PFAS to replace the interim Environmental Health Standing Committee guidelines released on 16 June 2016. FSANZ has provided the Commonwealth with a PFAS hazard assessment report (the FSANZ PFAS Report), which details the development of Tolerable Daily Intake (TDI) values for PFAS. This report forms the basis of the new Commonwealth guidelines.

A TDI is the amount of a chemical in food or drinking water that can be ingested over a lifetime without appreciable risk to the consumer. The TDI values proposed in the FSANZ PFAS Report are much more conservative than the interim health reference values and generally more consistent with those developed by the US EPA in 2016, which are the most conservative across the world.

The Commonwealth released new health based guidance value for PFOS and PFOA on 3 April 2017, including tolerable daily intakes for each, as well as new drinking water and recreational water quality guidelines and accompanying facts sheets on PFAS.

These new national health based guidance values will be used to compare and update sampling results for fish, crab, drinking water and recreational water. All NT sampling results are currently being reassessed using the new Commonwealth guidelines by Charles Darwin University and University of Queensland.

Frequently Asked Questions (FAQ)

Previous Guidance Information


Other Useful Links


Media Releases

NT EPA

8 April 2016: Joint investigation into fire-fighting foam presence (Rapid Creek and Ludmilla Creeks)

6 May 2016: The facts about PFCs (PFOS and PFOA) in Rapid Creek

20 March 2017: NT EPA to take part in PFAS Summit

Department of Health

9 August 2017: Water Conservation Measures to be introduced in Katherine 

9 August 2017: Water Treatment Plant to be provided to Katherine Community

27 July 2017: PFAS Reports for Rapid and Ludmilla Creeks

19 July 2017: Katherine Town Water Supply and PFAS Testing Results

3 April 2017: NT Minister for Health acknowledges the release of  Commonwealth PFAS Guidelines

8 November 2016: Statement from Department of Health

15 November 2016: Drinking Water Advice - Katherine Rural Area

Power and Water Corporation

18 November 2016: Drinking water quality testing update

25 November 2016: PFAS testing - NT public water drinking supply

Latest Results: PFAS testing of drinking water