Fire Fighting Foam (PFAS) Investigation
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.
- NT PFAS Investigation Strategy
- PFAS Interagency Working Group Terms of Reference
- Decision Tree for Prioritising Sites Potentially Contaminated Sites with PFASs
Water Testing in the Katherine Region
Rapid and Ludmilla Creeks
A joint investigation by the DoH and the NT EPA in February 2016 identified the presence of PFAS at various sites along Rapid Creek and Ludmilla Creek. Water testing results indicated that the creeks are at levels suitable for recreational use. although the levels of PFAS in various species of aquatic foods (such as fish and shellfish) were not known. Drinking water from Rapid Creek or Ludmilla Creek is not advised due to fluctuating microbiological water quality, and it is understood that groundwater is not extracted for human consumption.
As a precautionary measure DoH issued an advisory on 18 May 2016 recommending against the consumption of foods from these creeks until a sediment and aquatic life study was completed. The advisory was supported by signage being erected at relevant locations along the creeks, as well as distribution of fact sheets and media coverage.
DoH subsequently commissioned Charles Darwin University (CDU) in June 2016 to undertake a study of PFAS in sediment and aquatic life, in cooperation with Senior Rangers from the Larrakia Nation Aboriginal Corporation who collected samples and the University of Queensland's National Centre for Environmental Toxicology which analysed them.
- CDU full report: Per- and poly-fluoroalkyl substances (PFAS) testing in sediment and aquatic foods from Darwin Harbour
- CDU summary report
- PFAS Factsheet
The CDU report indicates that PFAS is present in sediment and aquatic life in Rapid and Ludmilla Creeks. PFAS was detected in aquatic sediment and aquatic food species commonly harvested by Indigenous people, including several species of mollusc, termed ‘traditional’ aquatic foods.
Further investigation is underway to understand the risks of consuming recreational catches of fish, crab and prawns around these creeks and Darwin Harbour. Fish, crab and prawn samples from the Ludmilla Creek, Rapid Creek and Darwin Harbour areas have been provided to the University of Queensland's Nationa Centre for Environmental Toxicology for further analysis of PFAS levels and a report is expected to released by end of June 2017.
As a precaution, signs are in place around the creeks to warn people that testing is underway and advising people no to eat the aquatic species from this area until further test results are known.
In any case, people are reminded to adhere to the fish consumption guidelines published by Food Standards Australia New Zealand and available at: http://www.foodstandards.gov.au/consumer/chemicals/mercury/documents/mif%20brochure.pdf
The CDU report indicates that levels of PFAS in all sediment samples complied with draft interim trigger values for ecological protection established by CRC CARE in 2015. However levels of PFAS in water samples collected by DoH/ NT EPA in February 2016 exceed draft ANZECC interim water quality trigger levels for ecological protection.
Further sampling is necessary to investigate the risks to ecological communities. Imminent finalisation of draft ANZECC interim water quality trigger levels and guidance for PFAS will be important in assessing the ecological significance of existing and future results from sampling.
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 was held on 22 March in Darwin and a session is scheduled for Katherine on 12 April 2017.
Further information about the Defence National PFAS environmental investigation program 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
- NSW Environmental Health PFOS and PFOA Factsheets
- enHealth Guidance Statements on per and poly-fluoroalkyl substances
- enHealth Interim national guidance on human health reference values for per- and poly-fluoroalkyl substances for use in site investigations in Australia
Other Useful Links
- Australian Government Department of Environment and Energy
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE)
- Environment Protection Authority – Victoria
- NSW Environment Protection Authority
- USA EPA
8 April 2016: Joint investigation into fire-fighting foam presence (Rapid Creek and Ludmilla Creeks)
20 March 2017: NT EPA to take part in PFAS Summit
Department of Health
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