Wessex Water Tap Water Quality

Wessex Water supplies Dorset, Somerset & Wiltshire with drinking water drawn from chalk and Jurassic limestone aquifers in Dorset and Wiltshire, plus River Avon and Somerset surface water sources.

Wessex Water covers the western chalk belt and Somerset Levels. Water hardness varies considerably across the region: zones in Dorset and Wiltshire drawing from chalk and Portland limestone are hard to very hard at 200–280 mg/L, while Somerset zones supplied from surface water tend to be moderately hard at 150–180 mg/L. Wessex Water has a generally good compliance record. Nitrate levels in some Wiltshire chalk zones are elevated due to agricultural abstraction. PFAS monitoring has identified concerns at a small number of sites.

Typical water profile

With typical hardness of approximately 210 mg/L CaCO₃, water in the Wessex Water supply area is classified as hard. This means significant limescale buildup on kettles, showerheads, and heating elements over time. A water softener or quality filter jug is a worthwhile investment for most households in this area.

Notable: Variable hardness — Dorset/Wiltshire hard (~200–280 mg/L), Somerset zones moderately hard. Good overall compliance record. Active PFAS improvement programme under DWI enforcement.

Is Wessex Water water safe to drink?

Yes. All treated water supplied by Wessex Water meets the UK Drinking Water Regulations. The Drinking Water Inspectorate (DWI) audits every water company annually — Wessex Water serves 2.8 million customers across 20 supply zones. Each zone is tested thousands of times per year and results are published in the annual compliance report.

However, water quality varies significantly between zones within the Wessex Water supply area. Your specific zone may have different hardness, nitrate, or THM levels from your neighbour in a different zone. That's why it's worth checking your exact postcode above.

How to check your Wessex Water zone

Enter your postcode in the box above to see zone-specific data for your address — including hardness, nitrates, lead, chlorine, fluoride, and THMs — drawn directly from Wessex Water's most recent annual compliance report.