Halesowen Water Hardness & Quality Report (2026)

Halesowen, the town in the Metropolitan Borough of Dudley in the south-west Black Country, is supplied by Severn Trent Water from the Elan Valley Reservoir system in mid-Wales conveyed via the West Midlands Aqueduct to Frankley Water Treatment Works. The Elan Valley supply — drawn from the soft upland Welsh reservoirs of the Elan and Claerwen rivers — provides the dominant supply chemistry for the wider West Midlands area. However, Halesowen's position in the south Dudley urban fringe, where the Triassic sandstone aquifer of the Black Country and the Stour valley catchment make contributions to the distribution blend, moderates the very soft Elan Valley baseline upward to moderately hard values. The River Stour in the west Midlands drains through Triassic sandstone country, adding moderate calcium.

Halesowen's hardness of 148 mg/L (10.4°Clark) is above the very soft Elan Valley supply (~60 mg/L at Frankley), reflecting the network blending and local catchment contributions in the south Dudley supply zone. The Triassic Sherwood Sandstone aquifer beneath parts of the south Black Country contributes moderate calcium to the distribution blend, and Severn Trent's broader Midlands network incorporates harder groundwater that is distributed alongside the Elan Valley supply. The Drinking Water Inspectorate (DWI) classifies this supply as moderately hard.

Limescale is a moderate household concern in Halesowen. At 148 mg/L, limescale forms gradually — kettles need descaling every one to two months and deposits on taps and showerheads accumulate moderately. Combi-boiler heat exchangers accumulate modest deposits; annual servicing with a limescale check is sensible. Washing-up liquid lathers reasonably well. Adding Calgon monthly to the washing machine and a regular kettle descale is adequate limescale management for most Halesowen households.