Ealing Common Water Hardness & Quality Report (2026)

Thames Water supplies Ealing Common in the London Borough of Ealing in west London, via the Thames Water west London ring main drawing from the River Thames treated at Walton-on-Thames and Hampton Water Treatment Works. At 245 mg/L (17.2°Clark), Ealing Common's water is hard, consistent with the chalk-dominated Thames catchment supply that defines water quality across all Thames Water zones in west and central London — a supply shaped by the Chiltern and North Downs chalk catchments far upstream.

The River Thames at Walton and Hampton arrives having traversed the Chiltern Chalk and North Downs Chalk catchments of the upper and middle Thames, carrying dissolved calcium bicarbonate from chalk springs and aquifer discharge throughout its catchment. The west London ring main distributes this chalk-river supply across the Ealing and west London distribution zone, producing consistently hard water with TDS 625.3 mg/L regardless of the local London Clay geology that underlies the Ealing plateau. The chalk hardness is imported entirely from the catchment uplands rather than from any local geology beneath west London.

At 245 mg/L, limescale is a persistent household challenge in Ealing Common. Kettles should be descaled monthly to maintain element efficiency. The combi-boiler benefits from a fitted scale inhibitor to protect the heat exchanger, and annual servicing is recommended. Washing-up liquid requires more product than in softer areas to achieve satisfactory lather. Taps and shower heads develop visible white limescale within one to two weeks; a fortnightly wipe with white vinegar or a proprietary descaling product keeps fittings clean and prevents hard-water staining from accumulating permanently on surfaces and seals throughout the home.