Ewell Water Hardness & Quality Report (2026)

Ewell, in the Borough of Epsom and Ewell in Surrey at the foot of the North Downs chalk escarpment, is supplied by South East Water from the North Downs Chalk Aquifer directly beneath the town. Ewell sits at the spring line at the base of the Cretaceous Chalk of the North Downs — historically the Hogsmill river rose here as chalk springs, and the town name derives from the Anglo-Saxon word for spring. South East Water draws from chalk boreholes in the chalk of the Epsom Downs and North Downs plateau above Ewell, where the Upper Chalk is productive and very permeable. The chalk recharge zone of Epsom Downs and Banstead Downs is directly above, providing high dissolved calcium groundwater from direct chalk percolation. South East Water distributes to Ewell and the Epsom district from the chalk supply.

Ewell's hard water — 231 mg/L (16.2°Clark) — reflects the North Downs Chalk Aquifer of the Epsom and Ewell district, where the chalk beneath the Epsom Downs and North Downs plateau produces high dissolved calcium. The Drinking Water Inspectorate (DWI) classifies this supply as hard.

Limescale is a persistent household challenge in Ewell. At 231 mg/L, limescale forms in kettles within two to three weeks and monthly descaling is advisable. Combi-boiler heat exchangers accumulate deposits steadily — annual boiler servicing and an in-line scale inhibitor are recommended. Showerheads, taps, and shower screens develop regular deposits. Washing-up liquid lathers poorly. Using Calgon monthly in the washing machine and maintaining a regular descaling routine is important limescale management for Ewell households on the North Downs chalk supply.