Haywards Heath Water Hardness & Quality Report (2026)

Haywards Heath, the Mid-Sussex commuter town in the High Weald between the North and South Downs, is supplied by South East Water from the South Downs Chalk Aquifer — the Cretaceous Chalk of the Sussex South Downs and the Weald chalk country. South East Water draws from chalk boreholes south of Haywards Heath in the Upper Chalk of the South Downs, where the chalk aquifer is highly productive and yields very calcium-rich groundwater from the long chalk scarp of the South Downs from Lewes to Worthing. The chalk of the Sussex South Downs contributes substantial dissolved calcium in a supply characteristic of the south-east England chalk belt. South East Water treats and distributes through the Mid-Sussex supply network to Haywards Heath and the surrounding Weald towns.

Haywards Heath's hard water — 230 mg/L (16.1°Clark) — reflects the South Downs Chalk Aquifer in South East Water's Mid-Sussex supply zone, typical of the chalk-dominated south-east England hard water region. The Drinking Water Inspectorate (DWI) classifies this supply as hard.

Limescale is a persistent household challenge in Haywards Heath. At 230 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 Haywards Heath households.