PFAS: The "Forever Chemicals" and Their Impact on Water
PFAS are one of those water issues that can sound terrifying very quickly.
They are extremely persistent, they’ve been found throughout the environment, and research into their long-term effects is still developing.
So yes, I think they deserve our attention.
But I also think we need to talk about them properly. Not by making everyone feel that their water is suddenly dangerous, but by looking at what PFAS are, what testing has actually found in New Zealand, and what you can realistically do if you want to reduce your exposure.
What Are PFAS?
PFAS stands for per- and polyfluoroalkyl substances.
They are a large family of manufactured chemicals that have been used for decades because they resist heat, oil, grease and water. This has made them useful in products such as firefighting foams, non-stick cookware, stain-resistant fabrics, some food packaging and industrial coatings.
The problem is that many PFAS break down very slowly.
Once released, they can remain in soil and water for a long time. Some PFAS can also accumulate in people and animals, which is why they are often called “forever chemicals”.
Why Are People Concerned About Them?
Some of the most studied PFAS have been associated with changes to immune response, cholesterol, liver function, development and the risk of certain cancers.
But this is where the wording matters.
PFAS are not one single chemical. There are thousands of different compounds, with different properties and very different amounts of health research behind them. Risk also depends on which PFAS is present, how much you are exposed to and how long that exposure continues.
Health New Zealand says there is no conclusive evidence that PFAS exposure will necessarily result in future health problems, and that the evidence around some effects is still unclear.
This doesn’t mean PFAS should be ignored. It means we need to avoid turning an evolving area of science into a certainty that doesn’t exist.
What Has Been Found in New Zealand?
PFAS contamination has been identified around some locations where firefighting foams were historically stored or used, including aviation and defence sites.
That makes sense because firefighting foam has been one of the more significant known sources of PFAS entering soil and groundwater.
However, the wider New Zealand picture is more reassuring
In a national survey published in 2023, the Environmental Protection Authority tested 131 groundwater wells around New Zealand. PFAS were detected at very low levels in 15 wells, and all of the detected drinking-water values were below New Zealand’s Maximum Acceptable Values.
The EPA described the results as showing very little contamination in the areas tested and a low level of potential risk.
This is good news.
But it doesn’t prove that every water source or private bore is free from PFAS. The survey covered selected wells, not every water supply or household tap in the country.
PFAS can also be very localised. A water source near a known firefighting training area or other site where PFAS was heavily used may have a very different risk profile from the national average.
What Are New Zealand’s Current PFAS Limits?
New Zealand’s Drinking Water Standards came into force in November 2022 and include legally enforceable Maximum Acceptable Values for two PFAS measurements:
PFAS measurement | New Zealand Maximum Acceptable Value
PFHxS and PFOS combined | 70 ng/L
PFOA | 560 ng/L
One nanogram per litre is roughly equal to one part per trillion.
These standards are not static measures of perfect or zero-risk water. They are regulatory limits developed from the evidence and risk assessments available at the time.
Other countries are continuing to revise their guidance.
Australia updated its health-based PFAS values in June 2025 to:
PFAS | Australian guideline value
PFOS | 8 ng/L
PFHxS | 30 ng/L
PFOA | 200 ng/L
PFBS | 1,000 ng/L
The Australian and New Zealand values are not a completely direct comparison because New Zealand combines PFHxS and PFOS into one measurement.
However, the updated Australian limits for PFOS, PFHxS and PFOA are lower than New Zealand’s current values. This shows how quickly the science and regulatory response around PFAS are still moving.
It does not automatically mean that New Zealand drinking water is unsafe.
It does mean that meeting today’s legal standard is not necessarily the final word on what governments may consider acceptable in the future.
What Is New Zealand Doing About PFAS?
New Zealand has been gradually removing some of the larger known sources of PFAS.
The national phase-out deadline for PFAS-containing firefighting foams was December 2025.
The Environmental Protection Authority has also banned the import and manufacture of cosmetics containing PFAS from 31 December 2026. New Zealand is one of the first countries to introduce this type of cosmetics restriction.
These changes will help reduce new PFAS entering the environment.
They won’t immediately remove contamination that is already present in soil or groundwater, which is part of what makes PFAS such a difficult environmental issue.
Should You Test Your Water?
For most people on a monitored New Zealand town supply, the first step is not necessarily to order a private PFAS test.
You can begin by asking your water supplier whether PFAS testing has been completed and whether the results are publicly available.
Testing may be more relevant if you use a private bore or groundwater source close to a known or suspected PFAS source, such as:
1. An airport or aviation facility
2. A firefighting training ground
3. A defence site
4. An industrial site where PFAS may have been stored or used
PFAS testing is specialised and should be carried out by a laboratory experienced in PFAS analysis. Because these chemicals are found in many everyday products, samples can be accidentally contaminated during collection.
Can Water Filters Reduce PFAS?
Yes, but not every water filter will reduce PFAS equally.
The three main technologies recognised for PFAS reduction are:
1. Granular activated carbon
2. PFAS-selective anion exchange resin
3. High-pressure membrane filtration, including reverse osmosis
Performance depends on the exact PFAS present, the incoming concentration, water chemistry, flow rate, contact time, filter size and how regularly the cartridge or membrane is replaced.
Carbon can work particularly well for some longer-chain PFAS, including PFOA and PFOS.
However, shorter-chain PFAS can be more difficult for carbon to capture. This means that simply seeing “activated carbon” on a product description doesn’t prove that the filter will perform well across the full PFAS family.
Reverse osmosis has shown strong PFAS reduction in home filtration studies, but it still needs to be correctly installed and maintained. Filters and membranes should be changed according to their recommended schedule because performance can decline as they age or reach capacity.
PureRevive uses reverse osmosis and ACtivated Carbon, which is one of the recognised filtration approaches for reducing PFAS and other dissolved contaminants. Actual performance will always depend on the source water, contaminants present and how the system is maintained.
A Balanced Way to Think About PFAS
Do I think every New Zealander needs to panic about PFAS in their tap water?
No.
The national groundwater results we currently have are generally reassuring.
Do I think PFAS should be dismissed because most tested levels were low?
Also no.
PFAS are extremely persistent. We are still learning about many of the compounds within this family, overseas limits are changing, and contamination can be concentrated around particular sites.
For me, the sensible response is:
1. Understand where your water comes from
2. Look for local testing rather than assuming
3. Test private groundwater where there is a genuine reason for concern
4. Choose filtration based on evidence, not just broad marketing claims
5. Replace filters and membranes on time
Water reflects the way we live.
The more persistent substances we manufacture and release into our environment, the more likely they are to eventually find their way back into our soil, food and water.
The long-term answer isn’t only better filtration. It is also reducing the amount of persistent chemistry we put into the world in the first place.
Until then, good testing, transparent information and properly selected filtration give us a practical way to make more informed choices at home.
