Telford Water Hardness & Quality Report (2026)

Telford, the new town in Shropshire designated in 1968, is supplied by Severn Trent Water, drawing primarily from the River Severn abstracted at Trimpley Water Treatment Works near Bewdley in Worcestershire. This surface water supply is supplemented by licensed boreholes into the Triassic Sherwood Sandstone and Mercia Mudstone aquifer systems beneath the Shropshire–Staffordshire border. The River Severn at Trimpley has traversed the Welsh Marches and Shropshire hills, picking up moderate dissolved mineral content from limestone outcrops along its course before reaching the treatment works. Water is treated and distributed northward through Severn Trent's network to Telford, where the new town's rapid expansion from the former Dawley, Madeley, and Oakengates townships created a major new demand centre in the 1970s and 1980s.

Telford's hardness of 190.5 mg/L (13.4°Clark) reflects the blended surface and groundwater geology. The River Severn above Trimpley drains limestone catchments in mid-Wales and the Shropshire hills, carrying moderate dissolved calcium. The local Triassic Sherwood Sandstone and Mercia Mudstone groundwater component — drawn from red-bed aquifers beneath the Shropshire plateau — contributes additional dissolved minerals from continental evaporite sequences within the Triassic formations. The blended result is classified as moderately hard by the Drinking Water Inspectorate (DWI).

Limescale is a consistent feature of Telford homes. At 190.5 mg/L, limescale forms in kettles within three to four weeks and monthly descaling is advisable. Combi-boiler heat exchangers accumulate limescale at a steady rate — annual boiler servicing with a limescale check is important, and an in-line scale inhibitor is a sensible addition to any boiler cold feed. Showerheads and taps develop regular limescale deposits. Washing-up liquid lathers moderately. Using Calgon monthly in the washing machine and maintaining a routine kettle descale is sufficient limescale management for most Telford households.