Leigh Water Hardness & Quality Report (2026)

Leigh, in the Metropolitan Borough of Wigan in south Lancashire between Wigan and Eccles on the south Lancashire coal measure plain, is supplied by United Utilities from the Thirlmere Lake District aqueduct and the River Dee treated at Huntington Water Treatment Works near Chester. The Thirlmere aqueduct delivers very soft water from the Borrowdale Volcanic catchment of the central Lake District, and the Dee supply from its Snowdonian and north Wales upland headwaters contributes further soft water. Leigh's position in the Borough of Wigan places it in the United Utilities south Lancashire supply zone predominantly fed by the soft Thirlmere and Dee supply corridor, with minimal local hard groundwater blending. The south Lancashire coal measure plain receives United Utilities distribution network supply that is consistently soft across the Wigan borough area.

Leigh's soft water — 80.5 mg/L (5.6°Clark) — reflects the soft Thirlmere and Dee supply dominant in the south Lancashire United Utilities distribution zone. The Drinking Water Inspectorate (DWI) classifies this supply as soft.

Limescale is very minor in Leigh. At 80.5 mg/L, limescale builds slowly — kettles need descaling every two to three months. Combi-boiler heat exchangers accumulate minimal deposits; annual servicing is routine. Showerheads and taps remain largely clear. Washing-up liquid lathers well with the soft south Lancashire supply. Limescale is not a significant domestic concern for Leigh households on the United Utilities Thirlmere and Dee supply.