The published numbers
What's in Perth's tap water?
In parts of Perth, the tap water would be illegal to supply in the European Union.
Perth is a postcode lottery: hardness swings from 26 to 228 mg/L depending on the suburb, and some localities average ~131 µg/L of trihalomethanes — over the EU's legal limit of 100. Legal here, because Australia allows 2.5× more and enforces none of it. Fluoride is added at 0.7–1.0 mg/L across the scheme.
Trihalomethanes (THMs)
Up to ~131 µg/L by locality · EU legal limit is 100
Water hardness
26–228 mg/L · a suburb lottery — yours could be 9× harder
Fluoride
Added · 0.7–1.0 mg/L
Chlorine
Dosed mains-wide — in every shower and glass
Sodium
~21–127 mg/L by suburb
Dissolved solids (TDS)
~129–576 mg/L by suburb — another postcode lottery
E. coli
100% — every locality, all year
Every figure comes from Water Corporation's published reporting — Drinking Water Quality Annual Report 2024–25. Measured where the water leaves the plant — the mains to your door are never tested.
These are the city-wide numbers. Yours are more specific.
Type your address and we'll map your suburb's own report — what's in the water when it reaches your street, and which of it is fixable at home.
Get my street's report → 60 seconds · no email · your suburb's own numbers