Chaddesden Water Hardness & Quality Report (2026)

Severn Trent Water supplies Chaddesden, a large residential suburb on the east side of Derby — a community of postwar housing estates between the city centre and Spondon, near the former Rolls-Royce aero-engine testing grounds — from Derwent Valley Reservoirs in the Peak District blended with a substantial proportion of Triassic Sherwood Sandstone groundwater in the east Derby distribution zone, treated at Bamford Water Treatment Works. At 186.5 mg/L (13.1°Clark), Chaddesden's water is hard — considerably harder than the north Derby suburb of Oakwood (112.5 mg/L) — reflecting a higher Triassic Sandstone groundwater fraction in the east Derby distribution sub-zone.

Chaddesden sits in the east Derby distribution zone where the Permo-Triassic Sherwood Sandstone aquifer of the east Derbyshire and Nottinghamshire plain provides a larger proportion of the supply blend than in the north Derby zones. The Triassic Sandstone yields moderately hard to hard calcium and sulphate-rich groundwater, and its greater contribution to the east Derby supply blend explains the significantly harder 186.5 mg/L with TDS 496 mg/L at Chaddesden compared to 112.5 mg/L at Oakwood — a striking illustration of how distribution blend variations create markedly different water quality within a single city.

At 186.5 mg/L, limescale is a persistent household concern in Chaddesden. Kettles benefit from descaling every three to four weeks. The combi-boiler should be fitted with a scale inhibitor and serviced annually. Washing-up liquid requires more product per wash than in softer Derby suburbs. 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 and prevents staining from building up permanently in this hard east Derby Triassic Sandstone groundwater-blend supply zone.