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.
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.
Testing at Ohakea and Woodbourne bases has shown the presence of PFAS compounds above recently adopted interim guidelines.
Results from two rounds of testing have now been reported back to landowners and residents at neighbouring properties. The testing area around both bases was expanded following the results of the first testing in January.
In the latest round of testing in February, six wells at Ohakea servicing eight households returned results at or above the interim drinking water guidelines. Those households are being supported by the NZDF liaison teams and other government agencies.
At Woodbourne, one result was found to contain PFAS concentrations above interim guidance levels for drinking water, but the well from which the sample was taken is not used for drinking water. Two samples above guidance levels previously were found to be under those levels in second stage testing.
NZDF continues to offer bottle drinking water and water tanks to those most impacted.
More tests will be carried out during the year.
Bases where firefighting training has been carried out but where the drinking-water is sourced remotely (eg Whenuapai, Hobsonville 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 is starting 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 will start early March.
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.