Atherstone Water Hardness & Quality Report (2026)

Severn Trent Water supplies Atherstone, the north Warwickshire market town on Watling Street (A5) — an ancient market town with a medieval bull-running tradition on Shrove Tuesday, situated on the boundary of the ancient Arden and Charnwood forest landscapes at the Warwickshire–Leicestershire border, and home of the Hat and Coat industries that once made Atherstone hats famous nationally — from Derwent Valley Reservoirs in the Peak District blended with Triassic Mercia Mudstone (Keuper Marl) groundwater in the north Warwickshire distribution zone, treated at Loughborough Water Treatment Works. At 240.5 mg/L (16.9°Clark) and a TDS of 703.3 mg/L, Atherstone's water is hard with a very elevated TDS/hardness ratio (2.93), indicating substantial sulphate from gypsum (calcium sulphate) dissolution within the Triassic Mercia Mudstone sequence of north Warwickshire.

Atherstone lies on the north Warwickshire Triassic Mercia Mudstone (Keuper Marl) plain where gypsum nodules are common in the subsurface Triassic sequence. Severn Trent blends soft Derwent Valley reservoir supply with Triassic Mercia Mudstone groundwater carrying significant sulphate from gypsum dissolution, producing 240.5 mg/L with TDS 703.3 mg/L — hard, sulphate-type water characteristic of the north Warwickshire Keuper Marl supply zone, comparable to Nuneaton (250 mg/L, TDS ~700) and Bedworth in the same north Warwickshire Triassic distribution corridor.

At 240.5 mg/L, limescale is a persistent household challenge in Atherstone. Kettles should be descaled monthly. The combi-boiler benefits from a fitted scale inhibitor and annual professional servicing. Washing-up liquid requires generous quantities 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-enriched Triassic supply at Atherstone is a product of the Keuper Marl plain beneath the town — the same Triassic geology that once made north Warwickshire a centre for hat-blocking steam, now leaving its mark on every Atherstone kettle.