Westbury Water Hardness & Quality Report (2026)

Wessex Water supplies Westbury, a market town in south-west Wiltshire at the edge of Salisbury Plain, famous for the Westbury White Horse carved into the chalk escarpment. Supply is drawn from the Wiltshire Chalk aquifer beneath Salisbury Plain and from the River Frome catchment in the Wiltshire–Somerset border country, treated at Bruton and regional Wiltshire works before distribution across the southern Wiltshire supply zone. At 165 mg/L (11.6°Clark), Westbury's water is moderately hard, reflecting the chalk and limestone geology that underlies the Wiltshire plain and shapes its landscape.

The Wiltshire Chalk — the broad downland plateau of Salisbury Plain — forms a highly productive aquifer recharged from rainfall over the open downs. Groundwater from the chalk percolates through hundreds of metres of porous limestone, dissolving calcium carbonate to produce moderately hard calcium bicarbonate water. The River Frome and other Wiltshire catchments drain a mix of chalk and Jurassic limestone, contributing surface water of comparable character to the supply blend. Together, these chalk and limestone sources produce the moderately hard supply typical of communities in the Wiltshire chalk vales.

At 165 mg/L, limescale is a noticeable domestic concern in Westbury. Kettles benefit from descaling every four to six weeks to maintain efficiency. The combi-boiler should be fitted with a scale inhibitor and serviced annually. Washing-up liquid performs adequately at normal quantities. Taps and shower heads develop moderate limescale deposits over a few weeks; a monthly wipe with white vinegar or a mild descaler keeps fittings in good condition. The chalk escarpment that carved the Westbury White Horse is the same geology that defines the moderately hard water supply of this classic Wiltshire downland town.