PFAS
PFAS (per- and polyfluoroalkyl substances) are a group of synthetic chemicals, commonly called “forever chemicals.” These substances have been used since the 1950s in the production of a wide range of heat, stain, grease and water-resistant products, including furniture protectants, floor waxes and specialised firefighting foams.
Most PFAS are engineered to be extremely durable, lasting for thousands of years, which is why they're often called ‘forever chemicals’.
People are exposed to small amounts of some PFAS in everyday life, through food, dust, air, water and contact with products that contain these compounds. There is evidence that there may be health effects associated with sustained exposure to some PFAS.
Unsafe levels of PFAS in aquatic life have been detected in the Makowhai Stream located in Ōhākea. Whilst there is no immediate risk to human health it is recommended to not consume the fish in the Makowhai stream.
PFAS water contamination in the Horizons Region
Central government agencies worked closely with local councils to ensure PFAS detections were handled appropriately.
You can read about the All of Government PFAS response on the MfE website.
PFAS at Palmerston North Airport
In 2018, an investigation at Palmerston North Airport revealed the presence of PFAS in soil, surface water, and groundwater around the airport. Surface water results were all above the interim drinking water guidelines.
PFAS were understood to have been used at Palmerston North Airport for fire training purposes up until the late 1980s. Since then, approximately 250 litres of firefighting foam have been used to test fire truck foam systems. Testing with foam ceased in December 2017.
The Palmerston North water supply is unaffected and safe for consumption. MidCentral DHB Public Health Services advises the public that there are no concerns about acute health issues arising from exposure to PFAS.
The Ministry for Primary Industries recommends that people avoid gathering food such as eels and watercress at:
Mangaone Stream
Richardsons Line Drain (including its headwater tributaries that cross Railway Road to the east of the Airport)
Various streams near the airport, flowing through Madison Ave and Jefferson Cres area, Clearview Park and McGregor Street
PFAS in Bulls Township
Sampling of the Bulls and Sanson water supplies was initially completed by NZDF at the request of Manawatū and Rangitīkei District Councils and Horizons Regional Council as part of the Base Ohakea investigation. Testing results were clear of PFAS in the Sanson water supply but returned low-level positive results (below the Ministry of Health interim drinking water guideline values) in four of the five Bulls water supply groundwater bores.
Currently, there does not appear to be an immediate health risk to the local community due to positive detections of PFAS in the Bulls water supply, and this water is considered safe for human consumption.
In July 2018, Horizons engaged the environmental consultancy firm Jacobs to determine the extent of PFAS in surface and groundwater and to identify potential sources of contamination.
PFAS around Ohakea Airbase
In late 2017, the Government announced it was testing properties around the New Zealand Defence Force (NZDF) Base Ohakea for possible PFAS-related water contamination. This followed the discovery of contamination on the base itself, arising from the use of certain firefighting foams in the past. NZDF has not used these foams since 2002.
Testing of neighbouring properties found that a number had drinking water containing PFAS compounds above the Ministry of Health interim guideline values. People at affected properties were offered alternative drinking water and individual health and food safety advice.
Since 2020, Horizons, in partnership with the NZDF, has been monitoring ground and surface water in and around Ohakea Airbase twice a year. We have engaged the independent organisation, Pattle Delamore Partners, to undertake the monitoring and report on the data. These reports are available to read below.
PFAS around Mākowhai Stream, Ohakea
Due to historic activities at RNZAF Base Ohakea, PFAS have entered the surface water and groundwater surrounding Ohakea.
In late 2025, Horizons was informed about the findings of Massey University-led research where PFAS concentrations were analysed in tuna (eel) samples sourced from the Makowhai Stream. The study found the livers of the native shortfin eels have PFAS concentrations exceeding Food Safety Australia and New Zealand’s (FSANZ) trigger values. As a result of these findings, Horizons sought to better understand PFAS concentrations in stream water, sediment and aquatic life along the Makowhai Stream.
Report Summary
Horizons’ have engaged with PDP to undertake the sampling analysis and reporting of the Makowhai Stream. The report found tuna flesh samples collected from the stream are significantly above the Ministry for Primary Industries' recommended ‘do not consume’ guidelines for recreational finfish. PFAS was also reported in samples of watercress collected from the stream. However, the concentrations are below FSANZ trigger point for further investigation. This means the risk to human health from the consumption of watercress is considered low. PFAS concentrations from sediment and surface water samples did not exceed human health guidelines for contaminated soil, or recreational water quality guidelines. The risk to human health from exposure to sediment and surface water at Makowhai Stream is considered low
Next steps
Horizons’ Regional Council are working with technical experts and relevant people to determine what further testing may be required of the Makowhai Stream waterways.
Makowhai Stream Environmental Sampling Report 2026
Ohakea PFAS monitoring reports
FAQs
How are people exposed to PFAS?
People are exposed to small amounts of PFAS in everyday life, through food, dust, air, water and contact with products that contain these compounds. These chemicals accumulate in people and wildlife over time.
What is the health risk form exposure to PFAS?
Te Whatu Ora Health New Zealand says “There is no conclusive evidence that PFAS exposure will result in future health problems. The evidence of health effects is not clear, and some effects may not be clinically significant.”
Limiting PFAS exposure is considered the best course of action to reduce possible long-term health risk.
When will we be able to harvest eels from the Makowhai stream again?
Given the persistence of PFAS and the long lifespan of eels, it is unlikely eels will be able to be harvested from the stream for some years.
If I am harvesting other species of fish in the Makowhai Stream, should I be worried?
Horizons’ Regional Council are working with technical experts and relevant people to determine what further testing may be required of the Makowhai Stream waterways. At this stage, we recommend not to consume fish in the area surrounding the Makowhai Stream. Once again, there is no immediate risk to human health. Limiting PFAS exposure is the best approach to reduce any potential long-term health risks.