NZDF is investigating the environmental impact of the historical use of firefighting foams containing substances known as PFAS.
PFAS stands for per- and poly-fluoroalkyl substances. They are a group of chemicals that have been widely used since the 1950s in a variety of household and industrial products resistant to heat, stains, grease and water. They have also been a component of firefighting foams that are applied to liquid fuel fires.
While PFAS compounds have been used widely for decades, recent investigations have identified that they are persistent and not known to degrade in the environment, and they also accumulate in humans and animals. So PFAS compounds are considered an emerging environmental contaminant.
Use of firefighting foams
Firefighting foams have been integral to maintaining safety for travellers, air crews and firefighters in the aviation environment internationally, and also in the maritime space. They have been used to quickly extinguish liquid fuel fires on airfields in emergency situations and for emergency training.
Foams used by NZDF since 2002 have not contained PFOS or PFOA above trace levels, according to advice received from our suppliers.
In a number of cases, our suppliers have also provided documentation verifying the foams meet the HSNO Firefighting Group Standard.
As an additional measure, NZDF commissioned testing of firefighting foams held by NZDF for use in firefighting. Samples of firefighting foam bulk stocks from Burnham, Devonport, Linton, Ohakea, Waiouru, Woodbourne and Whenuapai camps and bases were tested. The results showed PFOS and PFOA to be below the limit of reporting. These results are therefore consistent with the advice of our suppliers.
During the stocktake process, two 20 litre containers of foam were found segregated in storage awaiting disposal (not stored for current use), one at Devonport Naval Base and one at Waiouru Army Camp. Samples from these containers showed high concentrations of PFOS. This is consistent with these products pre-dating 2002. NZDF will be following the authorised disposal process, as outlined recently by the Environmental Protection Authority, to dispose of these two small segregated containers.
While NZDF’s current firefighting foams meet the HSNO Firefighting Group Standard, NZDF stopped training with firefighting foams at its air bases in 2016. Firefighting training moved to commercial fire training facilities at Taranaki and Auckland.
However, NZDF is currently not using AFFF firefighting foam for training anywhere in New Zealand, either on NZDF Bases or in commercial facilities, while long-term training options are assessed.
The Navy trains with a biodegradable ‘eco-foam’ in a contained environment at the Sea Safety Training Squadron in Devonport.
The Ministry for Environment is co-ordinating an all-of Government response to the issue of potential environmental contamination from the historical use of firefighting foams that contained specific PFAS compounds. As part of this NZDF is undertaking testing of ground and surface water at Ohakea and Woodbourne air bases and at neighbouring properties to understand the presence of PFAS in the environment. Preliminary investigations are also underway at Whenuapai Air Base and Devonport Naval Base.
NZDF has prioritised testing for PFAS at sites where firefighter training is known to have taken place historically, and where it is known that neighbours may be sourcing drinking water from bores or wells – Base Ohakea and Base Woodbourne.
Our expert consultants have advised that to get a robust picture of any PFAS in ground water, testing needs to take place in summer, autumn and winter - at varying water table levels. Three rounds of sampling have been completed at Ohakea and Woodbourne, and the results from the third round are expected soon. These results are provided to individual landowners, and a summary is provided to government agencies and regional authorities working on this issue. A fourth round of testing is planned for later in the winter when the water table will be at its highest.
NZDF is to begin testing the ground and surface water of a small number of properties near Whenuapai.
NZDF has been working to determine how and where the ground water flows to from Whenuapai Air Base, and to support the local community. Auckland Council has been consulted and has been assisting NZDF with our preliminary investigation with regional and locally specific information and knowledge.
Preliminary advice from NZDF’s consultants is that while some people may be using ground water at properties close to Whenuapai Air Base, the water is sourced from a bore at a depth of between 200-300 metres and below a thick layer of fine sediment that is expected to exclude PFAS. Testing will tell us more. Results are expected six to eight weeks after testing.
Drinking water at the base, the adjacent school, the village centre on Brigham Creek Road and the recently developed Special Housing Area comes from the town supply and is not affected.
Bases where firefighting training has been carried out but where the drinking-water is sourced remotely (eg Whenuapai and Devonport) are the next priority for investigation.
Research into the historical use of the former NZDF base at Hobsonville, and the remediation of the site carried out when NZDF vacated it, has cleared it as a possible source of concern for PFAS contamination.
NZDF is now assessing Devonport Naval Base. Initial testing of soils, sediments and runoff at the Sea Safety Training Squadron has found PFAS compounds in sample sites. More testing is to be carried out to confirm those initial findings and to provide more information.
Drinking-water on the base and in the community is sourced from Auckland city town supply and is therefore not affected.
NZDF has started limited testing of a tidal area, including of marine life, at Ngataringa Bay, to better understand the potential presence of PFAS in the area. This work is continuing.
MPI says that there is no evidence or suggestion that there is a current food safety issue. MPI food safety experts will review any findings.
Ministry of Health advice continues that there is no acute health risk.
More information about PFAS and the Government’s response to this issue, including health and food safety advice, is available at MFE.