Bournemouth Water Hardness & Quality Report (2026)

Bournemouth's water supply is managed by Bournemouth Water, now part of the South West Water group (Pennon Group), serving the conurbation of Bournemouth, Christchurch, and Poole on the Dorset coast. Supply is drawn primarily from licensed boreholes in the Eocene aquifer of the Hampshire–Dorset basin — principally the Boscombe Sand and Barton Clay formations, Tertiary-age sandy aquifers south of the New Forest — supplemented by contributions from chalk and greensand formations in the adjacent Hampshire uplands. Water is treated at Alderney Water Treatment Works in Bournemouth and other Bournemouth Water facilities before distribution to the south coast conurbation. The company serves approximately half a million customers across the Bournemouth and Poole urban area.

Bournemouth's moderate hardness of 90 mg/L (6.3°Clark) reflects the mixed Tertiary and Cretaceous geology of its source aquifers. The Eocene Boscombe Sand and Barton Sand formations are relatively young, loosely consolidated sandy aquifers that dissolve calcium only moderately compared to the older, denser chalks. The modest contribution from Cretaceous Chalk and Greensand formations in the Dorset–Hampshire border area adds a small additional calcium increment. The result is water softer than the hard chalk-belt cities to the north, classified as moderately soft by the Drinking Water Inspectorate (DWI) — one of the softer supplies in South England outside of the West Country.

Limescale is a relatively minor concern for Bournemouth residents compared to most of southern England. At 90 mg/L, limescale forms slowly — kettles typically need descaling every two to three months and showerheads and taps accumulate only modest deposits over time. Combi-boiler heat exchangers are under moderate limescale pressure, and annual servicing with a limescale check is good practice. Washing-up liquid lathers reasonably well at this hardness. A Calgon tablet added monthly to the washing machine and occasional kettle descaling with a proprietary descaler or white vinegar is sufficient limescale maintenance for most Bournemouth households.