You've probably seen the global headlines: "Rainwater is no longer safe to drink anywhere on Earth." Those stories, driven largely by a 2022 Stockholm University/ETH Zurich analysis, compared worldwide rainwater PFAS levels against extremely low U.S. EPA health advisories and concluded the thresholds were exceeded even in Antarctica and on the Tibetan Plateau.
In Australia the picture is different, and more reassuring for the millions of households that rely on rainwater tanks.
Australia's first rainwater PFAS study
In 2026, researchers from RMIT University and EPA Victoria published the first Australian measurements of PFAS in rainwater. They collected samples in Melbourne (about 20 km west of the CBD) on three occasions in 2024–2025 and tested for 30 compounds.
Eight PFAS were detected, generally at very low concentrations (nanograms per litre, or parts per trillion). Crucially, the two best-studied compounds, PFOS and PFOA, were below the current Australian Drinking Water Guidelines. Professor Oliver Jones of RMIT noted that the results "should provide some reassurance for people who use rainwater as a source of drinking water."
The study also estimated that rainfall might deliver roughly 10.6 kg of PFAS per year directly into Port Phillip Bay, and atmospheric modelling suggested air masses that had travelled over land carried higher concentrations than those from the ocean. This confirms rain as one atmospheric pathway for these persistent chemicals, even far from obvious industrial sources.
The difference in conclusions comes down to the benchmarks used. Australia's National Health and Medical Research Council (NHMRC) updated the Australian Drinking Water Guidelines in June 2025 after a comprehensive review. The health-based guideline values are:
PFOS: 8 ng/L
PFOA: 200 ng/L
PFHxS: 30 ng/L
PFBS: 1,000 ng/L
These are substantially higher than the ultra-low U.S. lifetime health advisories referenced in the 2022 global paper (on the order of 0.004 ppt for PFOA). Australian guidelines are set for lifetime exposure using local evidence and assumptions (including that drinking water accounts for only about 10% of total PFAS exposure for most people). Most municipal supplies already meet the new values, and NHMRC states that health risks from PFAS in drinking water remain low for most Australians.
In the Melbourne rain samples, levels stayed comfortably under these Australian thresholds even while some exceeded the older, stricter U.S. advisories.
Roughly 2–3 million Australian households use rainwater tanks, especially in regional and rural areas of Queensland, New South Wales, Victoria and South Australia. For many, tank water is the primary or sole drinking supply. State health departments have long advised that properly designed and maintained systems can produce water suitable for drinking, but untreated roof-harvested rainwater is never pure.
Common additional risks include:
Microbes (bird droppings, animal access)
Metals (lead, copper, zinc from roofs, gutters and fittings)
Sediment, leaves and organic matter
Location-specific contaminants (near airports, defence sites or industrial areas that used PFAS-containing firefighting foams)
The new PFAS data adds one more item to the monitoring list rather than a sudden crisis. Because the chemicals are highly persistent, background atmospheric deposition is now part of the baseline everywhere.
If you drink tank water, the priorities remain the same as they have been for years, with PFAS now part of the conversation:
1.System design and maintenance
Use a first-flush diverter, screened inlets, a covered tank, and suitable roofing materials. Keep gutters clear and the tank clean. State health guidance (NSW Health, Queensland Health, SA Health, etc.) has detailed checklists.
2.Test your water
Private tank owners are responsible for their own testing. Include microbial indicators, metals and, if you're concerned or live near known PFAS sites, a PFAS panel. Compare results to the current NHMRC guideline values.
3.Filtration if needed
oReverse osmosis (under-sink or countertop) is highly effective against a wide range of PFAS and is the most reliable single technology for drinking water. Look for NSF/ANSI 58 certification that specifically lists PFAS reduction.
oHigh-quality granular activated carbon or carbon-block filters certified to NSF/ANSI 53 for PFAS/PFOA/PFOS can also work well (especially for longer-chain compounds) when media is fresh.
oWhole-house systems exist but are more expensive; many households focus treatment on the kitchen tap used for drinking and cooking.
Standard sediment filters, UV sterilisation or boiling do not remove PFAS.
4.Other exposure reduction
Drinking water is only one pathway. Food, dust and consumer products are larger sources for most people. Choosing PFAS-free products where practical and maintaining good household hygiene helps overall exposure.
PFAS are a genuine global environmental challenge because of their extreme persistence and widespread use over decades. Australia's approach, science-based guideline updates, local monitoring, and continued source-control efforts through the PFAS National Environmental Management Plan, provides a more measured response than alarmist global headlines.
For the average Australian on town water, the risk remains low. For the many who depend on rainwater tanks, the first local study offers reassurance that current atmospheric levels are within Australian health guidelines, provided the rest of the system is well managed and the water is tested. Ongoing monitoring, proper maintenance and targeted filtration where needed are the practical ways forward.
Rain still falls clean enough, by Australian standards, to be a valuable resource, when we treat it with the care it has always required.