Quick answer: PFAS (per- and polyfluoroalkyl substances) reach drinking water mainly through industrial discharge, the use of aqueous film-forming foam (AFFF) at airports and fire-training sites, landfill leachate, and agricultural runoff from PFAS-contaminated biosolids. Once in soil or groundwater, these chemicals are highly persistent and can travel long distances before entering a water supply.
Why PFAS in drinking water matters for Australians
PFAS are a large family of synthetic chemicals used in manufacturing, firefighting, and consumer products for decades. Their carbon-fluorine bonds make them extraordinarily stable, which is why they are sometimes called "forever chemicals." That same stability means they do not break down readily in the environment or in the body, and they can accumulate in water sources over time.
Australian authorities have been monitoring and updating guidance on PFAS in drinking water. From 2023 to 2025, NHMRC reviewed guidance on PFAS in drinking water as part of an update to the Australian Drinking Water Guidelines. Understanding how PFAS enters water supplies is the first step to making sense of that guidance.
The main pathways: how PFAS gets into drinking water
PFAS does not appear in drinking water from a single source. Several distinct contamination pathways have been identified, and in many cases more than one operates at the same site.
Aqueous film-forming foam (AFFF) at defence and aviation sites
One of the most significant and well-documented sources of PFAS contamination in Australia is the historical use of AFFF at military bases, airports, and fire-training facilities. AFFF contains high concentrations of PFOS and PFOA, two of the most studied PFAS compounds. When foam was applied during training exercises or emergency responses, it soaked into the ground, migrated through soil, and entered groundwater. Communities near these sites have been among the first to have their water supplies tested and, in some cases, found to contain elevated PFAS levels.
Industrial manufacturing and discharge
Facilities that manufacture or use PFAS in their processes, including textile mills, electronics manufacturers, and chemical plants, can release PFAS into waterways through wastewater discharge. Even where discharge is treated, some PFAS compounds pass through conventional wastewater treatment largely unchanged, reaching rivers and reservoirs that feed drinking water systems.
Landfill leachate
Consumer products containing PFAS, such as non-stick cookware, food packaging, stain-resistant fabrics, and personal care products, eventually end up in landfill. As rainwater percolates through landfill waste, it picks up PFAS and forms leachate. If leachate is not fully contained and treated, it can seep into surrounding soil and groundwater, creating a diffuse but persistent contamination source.
Agricultural runoff from biosolids
Biosolids, the treated solid material left over from sewage treatment, are commonly applied to agricultural land as a fertiliser substitute. Because PFAS passes through wastewater treatment largely intact, biosolids can carry significant PFAS loads. When rain falls on treated farmland, PFAS can run off into streams or leach downward into aquifers that supply drinking water bores and reservoirs.
Atmospheric deposition
PFAS can also travel through the air. Volatile PFAS precursors released from industrial sites or consumer products can be carried by wind and deposited on land and water surfaces far from their original source. This pathway is less well understood than direct discharge but contributes to the widespread distribution of PFAS in the environment.
How PFAS moves through the environment to reach your tap
Once PFAS enters soil or surface water, its persistence drives its spread. Unlike many organic contaminants, PFAS does not degrade through natural biological processes at any meaningful rate. It binds to soil particles but also dissolves readily in water, allowing it to migrate with groundwater flow over years and decades. Surface water contamination can spread downstream through river systems, affecting water intakes that serve large populations. Groundwater contamination is often slower to appear but harder to address once established, because the source of contamination may be distant and the aquifer itself acts as a long-term reservoir.
Water treatment plants using conventional processes, including coagulation, sedimentation, and standard filtration, do not reliably reduce PFAS concentrations. This means PFAS that enters a source water supply can pass through treatment and reach household taps.
Australian drinking water guidelines for PFAS
Australian authorities have developed specific health-based guideline values for PFAS in drinking water. According to NHMRC, new and revised health-based guideline values have been developed for the following PFAS to reduce health risks from exposure to these chemicals in Australian drinking water.
The current values, as stated by NHMRC, are:
- PFOA (perfluorooctanoic acid): 200 ng/L
- PFOS (perfluorooctane sulfonic acid): 8 ng/L
- PFHxS (perfluorohexane sulfonic acid): 30 ng/L
- PFBS (perfluorobutane sulfonic acid): 1000 ng/L
These values replaced earlier interim figures. For context, NHMRC notes that in August 2018, NHMRC published health-based guideline values for three PFAS (PFOS plus PFHxS, and PFOA) in the Australian Drinking Water Guidelines. The previous combined PFOS and PFHxS value of 70 ng/L was a historical interim measure and has since been superseded by the separate current values listed above.
The Australian Drinking Water Guidelines now include revised health-based guideline values for PFOA and PFOS, a separate guideline value for PFHxS, and a new guideline value for PFBS, along with a dedicated PFAS Chemical Fact Sheet.
Which communities in Australia are most at risk?
PFAS contamination is not evenly distributed. Communities most likely to be affected include those near current or former military bases where AFFF was used, areas close to airports with a history of fire-training activities, towns downstream from industrial facilities that have historically used or manufactured PFAS, and rural communities relying on bores or surface water near land where PFAS-containing biosolids have been applied.
State and territory environment and health agencies publish information about known PFAS investigation areas. If you live near a site of concern, your local water authority or state health department is the appropriate source for current monitoring data and advice specific to your area.
What about PFAS in household tap water?
For most Australians connected to a reticulated water supply, the water authority monitors for PFAS and is required to act if levels exceed guideline values. However, monitoring programs vary by jurisdiction, and private bore users may not have the same level of oversight.
If PFAS reduction at the point of use is a priority for your household, Evolved H2O offers products with specific tested claims for PFAS. The Evolved H2O HydroX Electric Water Filter reduces Total PFAS, with a tested reduction of greater than 99.22%. The Evolved H2O 3.5L Glass Water Filter Jug reduces PFAS, with a tested reduction of 98.1%. The Evolved H2O Advanced Tap Filter targets PFAS, heavy metals, microplastics and chlorine.
Key takeaways
- PFAS enters drinking water through multiple pathways: AFFF use at defence and aviation sites, industrial discharge, landfill leachate, agricultural biosolids, and atmospheric deposition.
- PFAS is highly persistent and does not break down readily, allowing it to travel long distances through groundwater and surface water.
- Conventional water treatment does not reliably reduce PFAS concentrations.
- NHMRC has established current health-based guideline values for PFOA (200 ng/L), PFOS (8 ng/L), PFHxS (30 ng/L), and PFBS (1000 ng/L) in Australian drinking water.
- Communities near military bases, airports, industrial sites, and farms using biosolids face a higher likelihood of PFAS-affected water sources.
- Your state or territory water authority and health department are the best sources of local monitoring data.
Frequently Asked Questions
What are PFAS and why are they called forever chemicals?
PFAS (per- and polyfluoroalkyl substances) are a large group of synthetic chemicals built around extremely strong carbon-fluorine bonds. That bond strength makes them resistant to heat, water, and biological breakdown, which is why they persist in the environment and in living organisms for very long periods. The informal name "forever chemicals" reflects this persistence rather than any specific health finding.
Is PFAS in Australian tap water a widespread problem?
PFAS contamination is documented at specific sites across Australia, particularly near military bases and airports where aqueous film-forming foam was used. Most reticulated water supplies are monitored by water authorities. The risk is higher for communities near known contamination sites and for people relying on private bores in affected areas. Your local water authority can provide current monitoring results for your supply.
Does boiling water reduce PFAS?
Boiling water does not reduce PFAS. Because PFAS compounds are not volatile at boiling temperatures, they remain in the water. Boiling actually concentrates PFAS slightly as water evaporates. Boiling is effective for some biological contaminants but is not a useful approach for PFAS.
How do Australian guidelines for PFAS compare to earlier values?
Australian guidelines have been updated significantly. According to NHMRC, the previous combined interim value of 70 ng/L for PFOS and PFHxS was a historical measure. The current values, finalised as part of the 2023 to 2025 review, are separate figures for each compound: PFOS at 8 ng/L, PFOA at 200 ng/L, PFHxS at 30 ng/L, and PFBS at 1000 ng/L.
Can PFAS travel far from its original source?
Yes. PFAS is water-soluble and does not degrade, so it can migrate through groundwater and surface water systems over considerable distances and timescales. Contamination originating at a single industrial or military site can affect water sources kilometres away, which is why monitoring programs often extend well beyond the immediate vicinity of a known source.
Where can I find out if my local water supply has been tested for PFAS?
Your state or territory water authority and health department publish information about PFAS monitoring and known investigation areas. Contacting your water utility directly is the most reliable way to obtain current data for your specific supply. The NHMRC PFAS review page also provides background on the Australian regulatory context.
Sources
- NHMRC Review of PFAS in Australian drinking water | NHMRC
- Questions and answers on review of PFAS in drinking water | NHMRC
- Australian Drinking Water Guidelines | NHMRC
