The legacy of PFAS contamination at Palmerston North Airport and the mechanisms by which this contamination migrates off-site

Author: Grant, K., Lanham, D.

Source: Pattle Delamore Partners Ltd

Year: 2021

Abstract

Poly- and per-fluorinated alkyl substances (PFAS) have been used in firefighting foams since the 1950s. The PFAS form a surfactant layer which allows the foam to spread rapidly over burning volatile fuels, reducing the availability of oxygen and suppressing flames. The import, use and manufacture of PFOS and PFOA is currently prohibited in New Zealand. They are considered to be persistent organic pollutants with potential effects on human health and the environment.

Palmerston North Airport, like many other New Zealand airports, historically used PFAS containing foams for training and fire suppression between the 1960s and the 2000s. Regular training exercises were undertaken at a fire training area located to the north of the runway and foam was flushed from tanks and hoses near the former fire station located to the south of the runway. Fire training ceased in 1989 with peak foam usage occuring in the 1970s and 1980s.

The use of PFAS foams discontinued at Palmerston North Airport in 2017. A series of targeted investigations were commissioned by the airport company in 2018. Variable levels of PFAS were identified within the soils, stream sediments, surface water and groundwater in the vicinity of both the fire training area and fire station. PFAS bioaccumulates, therefore eels were considered to potentially be of risk to human health if consumed, due to their longevity. The results of biota sampling indicate that PFAS is present within eels collected from the surface waterways near the airport.