Great Malvern Water Hardness & Quality Report (2026)

Great Malvern, the spa town in Worcestershire at the foot of the Malvern Hills famous worldwide for soft spring water, is supplied by Severn Trent Water from the River Severn and River Teme catchments — a supply entirely distinct from the celebrated Malvern Spring natural mineral water. The Malvern Hills themselves are composed of ancient Pre-Cambrian basement rocks (Malvernian gneisses and schists — some of the oldest rocks in England) which dissolve virtually no calcium, producing the historically famous very soft spring water. However, the mains tap water supply is from Severn Trent, drawing from the River Severn (which carries dissolved calcium from the Jurassic limestone country of Gloucestershire and the Welsh Marches) and the Teme catchment — a completely different, harder water. Severn Trent distributes through the south Worcestershire network.

Great Malvern's moderately hard tap water — 173 mg/L (12.1°Clark) — contrasts strikingly with the very soft Malvern Spring mineral water and reflects the River Severn and Jurassic limestone catchment chemistry of Severn Trent's supply, not the Pre-Cambrian Malvern Hills geology. The Drinking Water Inspectorate (DWI) classifies this supply as moderately hard.

Limescale is a regular household concern in Great Malvern. At 173 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 consistent deposits. Washing-up liquid lathers moderately. Using Calgon monthly in the washing machine and a regular descaling routine is appropriate limescale management for Great Malvern households on the Severn Trent supply — which, despite the town's famous spring water heritage, is decidedly hard.