Hereford Water Hardness & Quality Report (2026)

Hereford, the cathedral city and county town of Herefordshire on the River Wye, is supplied by Severn Trent Water drawing from the River Wye catchment. The Wye is one of the principal rivers of the Welsh Marches, rising on Plynlimon in the Cambrian Mountains of mid-Wales and flowing south-east through Builth Wells, Hay-on-Wye, and Hereford before turning south to the Severn estuary. The Wye catchment drains predominantly ancient Old Red Sandstone (Devonian) and Silurian sedimentary rocks of Herefordshire and the Welsh Marches — relatively insoluble continental sandstones and siltstones deposited in semi-arid and shallow-marine conditions 400–430 million years ago. Severn Trent Water treats Wye abstraction at facilities serving the Hereford area. The soft, lightly mineralised Wye supply gives Hereford one of the softer supplies for a midland English city.

Hereford's hardness of 108 mg/L (7.6°Clark) reflects the Old Red Sandstone and Silurian bedrock of the Wye catchment. The Devonian Old Red Sandstone of the Herefordshire plain and the Silurian greywackes and limestones of the Malvern Hills fringe contribute only modest dissolved calcium, producing moderately soft water characteristic of the Welsh Marches. The Drinking Water Inspectorate (DWI) classifies this supply as moderately soft.

Limescale is a moderate concern in Hereford. At 108 mg/L, limescale forms gradually — kettles need descaling every one to two months and deposits on showerheads and taps accumulate slowly. Combi-boiler heat exchangers accumulate modest deposits; annual servicing is sensible. Washing-up liquid lathers reasonably well. The soft Wye supply gives Hereford good limescale management conditions — a monthly Calgon tablet in the washing machine and a periodic kettle descale with white vinegar is adequate maintenance for most Hereford households.