Castle Vale Water Hardness & Quality Report (2026)

Severn Trent Water supplies Castle Vale, the north-east Birmingham housing estate in the City of Birmingham — a large mid-20th century social housing estate built in the 1960s and 1970s on the former Castle Bromwich Aerodrome (from which Spitfire aircraft were test-flown during the Second World War), the estate subsequently regenerated through a housing action trust in the 1990s and 2000s with a transformed mixed residential character — from the Elan Valley Aqueduct (Birmingham Corporation Waterworks reservoir system in the Cambrian Mountains of Powys) blended with Triassic Mercia Mudstone groundwater in the north-east Birmingham distribution zone, treated at Frankley Water Treatment Works near Rubery. At 229.5 mg/L (16.1°Clark) and a TDS of 664.7 mg/L, Castle Vale's water is hard with a very elevated TDS/hardness ratio (2.90) — reflecting very significant sulphate from the Triassic Mercia Mudstone (Keuper Marl) and Coal Measures of the north-east Birmingham basin, which dramatically raises TDS above what the hardness alone would predict.

Castle Vale lies in the north-east Birmingham urban basin on the Permo-Triassic Mercia Mudstone plain, where the Severn Trent distribution network blends Elan Valley soft reservoir supply (from the Welsh Cambrian Mountains) with a proportion of Mercia Mudstone and Coal Measures groundwater. The Keuper Marl and Coal Measures contribute both calcium and very significant sulphate, producing 229.5 mg/L with TDS 664.7 mg/L — hard water with one of the highest TDS/hardness ratios in the Birmingham supply system (2.90), consistent with the north-east Birmingham Triassic basin.

At 229.5 mg/L, limescale is a persistent household challenge in Castle Vale. Kettles should be descaled monthly. The combi-boiler benefits from a fitted scale inhibitor and annual professional servicing. Washing-up liquid requires more product per wash. Taps and shower heads develop visible white limescale deposits within one to two weeks; a fortnightly wipe with white vinegar or a proprietary descaling product keeps fittings clean. The hard, sulphate-elevated supply at Castle Vale is characteristic of the north-east Birmingham Triassic basin — the Keuper Marl beneath the former aerodrome estate contributing calcium and sulphate to the water of one of Birmingham's most extensively regenerated neighbourhoods.