Cambridge Water Tap Water Quality

Cambridge Water supplies Cambridgeshire with drinking water drawn from chalk aquifers of the East Anglian chalk plateau, with boreholes across Cambridgeshire.

Cambridge Water is one of the UK's smallest water companies, serving Cambridge and surrounding Cambridgeshire towns. The entire supply is drawn from the East Anglian chalk aquifer — one of the most productive and pure aquifer systems in the country, but also one that produces extremely hard water. Cambridge water hardness typically runs 290–330 mg/L CaCO₃, placing it among the hardest in the UK alongside London, Luton, and Hull. Despite the very high hardness, the water is clean, low in nitrates (due to limited agricultural pressure near Cambridge), and has a very good compliance record. Cambridge Water was acquired by South Staffordshire Water.

Typical water profile

With typical hardness of approximately 310 mg/L CaCO₃, water in the Cambridge Water supply area is classified as very 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: Very hard water (~310 mg/L) from chalk aquifer. Among the hardest water in the UK. Very clean record with excellent nitrate and contaminant levels. No active PFAS notice.

Is Cambridge Water water safe to drink?

Yes. All treated water supplied by Cambridge Water meets the UK Drinking Water Regulations. The Drinking Water Inspectorate (DWI) audits every water company annually — Cambridge Water serves 0.3 million customers across 9 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 Cambridge 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 Cambridge 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 Cambridge Water's most recent annual compliance report.