Stowmarket Water Hardness & Quality Report (2026)

Anglian Water serves Stowmarket, the principal town of Mid Suffolk. Supply is sourced from a blend of groundwater abstracted from the Chalk aquifer of central Suffolk and surface water from the River Gipping catchment, treated at Stowmarket Water Treatment Works. The Chalk aquifer underlying central Suffolk is thickly developed and highly productive, contributing the majority of hardness to the town's supply. At 219 mg/L (15.4°Clark), Stowmarket's water is firmly in the hard category, consistent with the chalky geology characterising the East Anglian uplands.

The Upper Cretaceous Chalk of Suffolk forms a broad, gently undulating plateau extending across the county. Infiltrating rainfall dissolves calcium carbonate through the carbonic acid mechanism as it descends through the fractured chalk matrix, emerging at boreholes with high calcium bicarbonate content. The River Gipping itself, rising in the chalk country near Stowupland, carries dissolved carbonates throughout its catchment, so even the surface water component contributes meaningfully to hardness — making the supply consistently hard regardless of seasonal blending proportions between groundwater and surface water sources.

Limescale affects everyday life noticeably in Stowmarket. Kettles benefit from descaling monthly to keep elements clear and prevent chalky flakes from forming in drinks. The combi-boiler should be fitted with a scale inhibitor and serviced annually to check for heat exchanger deposit build-up. Washing-up liquid does not lather as easily as in softer-water regions, so slightly more detergent is typically needed per wash. Taps and shower heads develop visible white limescale deposits within a week or two; a fortnightly wipe with white vinegar or a proprietary descaler will prevent permanent staining and keep fittings in good working order for longer.