Walsall Water Hardness & Quality Report (2026)

Walsall, in the Metropolitan Borough of Walsall in the West Midlands, is supplied by South Staffordshire Water. Like neighbouring Dudley and Wolverhampton, Walsall receives a blended supply combining surface water abstracted from the River Severn at Trimpley Water Treatment Works in Worcestershire with licensed groundwater from the Triassic Sherwood Sandstone aquifer beneath the West Midlands. This local groundwater component — accessed through boreholes sunk into the Triassic sandstone underlying the Black Country — carries greater dissolved mineral content than the softer Severn surface water. Water is treated and distributed by South Staffordshire Water to Walsall and the wider Black Country, a region historically defined by metalworking, limestone quarrying, and coal extraction.

Walsall's hardness of 152.5 mg/L (10.7°Clark) reflects the West Midlands mixed supply geology. The Sherwood Sandstone aquifer — a Triassic formation deposited in arid, continental conditions approximately 230–250 million years ago — has been partially enriched with dissolved calcium and sulphate from surrounding Carboniferous limestone and evaporite layers in the Midlands basin. The River Severn contribution, abstracted upstream of the coal measures, carries some calcium from limestone catchments in Shropshire and the Welsh Marches. The blended result sits in the moderately hard band of the Drinking Water Inspectorate (DWI) classification — harder than Birmingham but softer than Wolverhampton.

Limescale requires regular attention in Walsall homes. At 152.5 mg/L, limescale forms in kettles over four to six weeks and descaling every four to six weeks is a sensible routine. Combi-boiler heat exchangers accumulate deposits over time, and annual boiler servicing with limescale inspection is advisable. Showerheads and taps develop steady deposits. Washing-up liquid lathers adequately. Adding a scale inhibitor cartridge to the boiler cold feed and using Calgon monthly in the washing machine is recommended for Walsall households looking to reduce limescale maintenance across their appliances.