Fareham Water Hardness & Quality Report (2026)

Fareham, the south Hampshire town at the north shore of Portsmouth Harbour in the Borough of Fareham, is supplied by Portsmouth Water from the South Downs Chalk Aquifer and chalk boreholes at Portsdown Hill — the chalk ridge running east-west behind Portsmouth and Fareham. Portsmouth Water operates its principal chalk abstractions in the Cretaceous Chalk of Portsdown and the east Hampshire South Downs dip-slope, distributing to Fareham, Gosport, Havant, and the Portsmouth conurbation. The Portsdown Hill chalk is the seaward edge of the South Downs chalk, and the chalk here produces moderately high dissolved calcium groundwater. Fareham's slightly lower hardness compared to Havant (206 mg/L) reflects its somewhat more westerly supply zone position on the Portsmouth Water network.

Fareham's moderately hard water — 189 mg/L (13.3°Clark) — reflects the South Downs Chalk Aquifer via Portsmouth Water's Portsdown chalk borehole supply. The South Downs chalk of east Hampshire produces consistently hard water across the Portsmouth Water supply area. The Drinking Water Inspectorate (DWI) classifies this supply as moderately hard.

Limescale is a regular household concern in Fareham. At 189 mg/L, limescale forms in kettles within three to four weeks and monthly descaling is sensible. Combi-boiler heat exchangers accumulate deposits at a moderate rate; annual servicing is recommended. Showerheads and taps develop regular deposits. Washing-up liquid lathers moderately. Using Calgon monthly in the washing machine and a regular descaling routine is appropriate limescale management for Fareham households on the Portsmouth Water chalk supply.