Friends of the Earth's analysis of Sydney Water's full GIPA-released dataset shows North Richmond carries the highest average PFOS and PFHxS detections in the entire network. In 2025, average PFOS at North Richmond was 0.001564 µg/L (1.564 ng/L) — 19.5% of the Australian guideline limit of 8 ng/L. Average PFHxS was 0.002347 µg/L (2.347 ng/L) — 7.8% of the 30 ng/L guideline. While well within Australian guidelines, PFOS at 1.564 ng/L exceeds the US EPA limit of 4 ng/L in some individual samples.

Some North Richmond samples measured PFOS around ~6 ng/L — below Australia's 8 ng/L guideline, but above the US EPA limit of 4 ng/L. The contamination source is attributed to historical firefighting foam use at nearby Richmond RAAF Base — a legacy military contamination site. Sydney Water installed additional granular activated carbon treatment at both plants following the June 2024 discovery. Cascade outlet (serving Blackheath and Katoomba) currently shows PFOS at 0.0013 µg/L and PFHxS at 0.0009 µg/L — both well within guidelines.

Prospect — which processes water from Warragamba Dam and serves the majority of Sydney's population — shows average PFOS at 0.0007 µg/L (0.7 ng/L) or 8.75% of the Australian guideline limit. The highest single detection in 2025 was 0.0011 µg/L (1.1 ng/L) on 15 September — 13.75% of the guideline. PFHxS averages 0.000783 µg/L (0.783 ng/L) — 2.61% of the 30 ng/L guideline. These are low levels by any comparison.

PFBA — which the UNSW study identified as the most abundant PFAS compound in Sydney water — was near zero at Prospect and Warragamba sites in 2024 for reasons not yet explained by Sydney Water, though it was detected at other network sites. PFBA is currently unregulated under Australian guidelines.

Melbourne Water's 2024–2025 testing across seven monitored catchment sites — including Thomson, Yarra Ranges, Tarago, Maroondah, and Yan Yean — found all four regulated PFAS compounds (PFOS, PFHxS, PFOA, PFBS) at less than 2 ng/L, the analytical detection limit, across all sites. This is effectively non-detect — no measurable PFAS in Melbourne's source water. This makes Melbourne's PFAS picture the cleanest of any Australian capital, and comparable to the world's best-quality municipal water supplies.

Victoria's Department of Health's 2023–24 Drinking Water Report did record 39 contamination incidents involving PFAS across the state — but these relate primarily to regional Victoria and groundwater sources near legacy industrial and AFFF sites, not to Melbourne's metropolitan supply. Some PFAS detections occur at regional Victorian water authorities after heavy rainfall events when industrial runoff enters affected waterways.

Seqwater's monthly monitoring detected PFOA in raw source water at Mt Crosby Westbank WTP at 36 ng/L in 2023, reducing to 23 ng/L in 2024. Treated (finished) water at all sites consistently tested below 2 ng/L — effectively non-detect — as of March 2026. The Australian guideline for PFOA is 200 ng/L, so treated water is comfortably compliant. However, the US EPA limit is 4 ng/L — meaning Brisbane's raw source water PFOA in 2023 exceeded the US limit by approximately nine times.

The source water contamination is attributed to PFAS leaching from upstream catchment areas with legacy AFFF use history. Seqwater's treatment process — which includes coagulation, flocculation, sedimentation, and disinfection — appears effective at reducing PFOA to near-undetectable levels in finished water. Community groups and Queensland Health have called for tougher guidelines following the Mt Crosby disclosures, with Queensland Health acknowledging the current Australian guideline of 200 ng/L for PFOA may be set too high.

The Water Corporation of Western Australia refuses to release any PFAS testing data — including under Freedom of Information legislation. This is in stark contrast to Sydney Water, which now publishes weekly PFAS results for its highest-concern plants. Perth draws water from surface catchments in the Darling Range, groundwater, and desalination — all of which carry different PFAS contamination risk profiles. Without publicly available data, Perth residents cannot make informed assessments of their exposure. The absence of transparency does not mean the water is unsafe — but it does mean it cannot be independently verified. Residents concerned about PFAS should request testing directly from the Water Corporation or use independent laboratory testing.

Adelaide's water supply draws primarily from the River Murray and Mount Lofty Ranges catchments. SA Water conducts PFAS monitoring and publishes annual water quality reports. South Australia's drinking water has historically met Australian Drinking Water Guidelines for PFAS. Adelaide's main water quality concerns are historically related to River Murray turbidity, algal blooms, taste and odour, and salinity rather than PFAS contamination, though all regulated PFAS compounds are monitored. SA Water publishes annual water quality results; residents can access these through the SA Water website.

Canberra's water is supplied from Googong Reservoir and Corin Dam via Icon Water. Both are surface water sources in protected catchments with relatively limited industrial exposure. The ACT does not appear on the national PFAS affected water supply areas register compiled by FilterOut from publicly available contamination reports. Icon Water publishes water quality data including PFAS monitoring results. The ACT's main PFAS-related concerns have been related to legacy firefighting training sites at RAAF Fairbairn, but these have not been identified as having materially impacted Canberra's drinking water supply at guideline-breaching levels.

Darwin's water is managed by Power and Water Corporation, drawing from Darwin River Dam and Manton Dam. The NT has a number of legacy AFFF contamination sites — including Darwin RAAF Base — that have impacted groundwater and surface water in some areas, though Darwin's metropolitan treated water supply is not publicly reported as exceeding PFAS guidelines. Hobart's water is supplied from the Derwent catchment by TasWater. Tasmania has fewer legacy industrial contamination sites than mainland states, and TasWater's published quality data does not identify PFAS as a primary concern for Hobart's metropolitan supply. Both utilities conduct PFAS monitoring, though public reporting is less detailed than Sydney or Melbourne.

Melbourne's protected catchment water has effectively undetectable PFAS levels across all monitored compounds. If PFAS is your primary concern, Melbourne tap water is currently the best-performing of any Australian capital. A water filter remains beneficial for chlorine, chloramines (Melbourne uses free chlorine, not chloramine), and other contaminants — but the PFAS argument for point-of-use filtration is weakest here.

Residents in areas supplied by North Richmond WFP and Cascade WFP face the highest PFAS levels in the Sydney network — with PFOS at levels that, while Australian-guideline-compliant, exceed the US EPA limit in some samples. Additionally, 31 PFAS types have been detected in Sydney water overall, most of which are unregulated. A reverse osmosis point-of-use filter or NSF 53-certified activated carbon filter for drinking water is a proportionate response for residents who want to reduce their PFAS intake below current Australian guideline levels.

Brisbane's treated water tests below 2 ng/L for all regulated PFAS as of March 2026 — well within Australian guidelines and below US EPA limits. The concern is primarily the source water PFOA levels and whether treatment will remain effective as upstream contamination evolves. Community groups continue to call for tougher Queensland guidelines in light of the Mt Crosby data. For Brisbane residents wanting additional assurance — or concerned about the broader range of unregulated PFAS — a point-of-use reverse osmosis filter is the most effective household option.

Perth residents are in the most difficult position of any Australian city: their water authority refuses to release PFAS testing data under FOI, making it impossible to independently verify the PFAS status of their supply. This is not necessarily cause for alarm — absence of data is not evidence of contamination — but it does mean Perth residents who want certainty about their PFAS exposure have no public option for verification. Independent household water testing through a certified laboratory, or a precautionary reverse osmosis filter for drinking water, are the practical responses available.