Oadby Water Hardness & Quality Report (2026)

Oadby, the affluent south Leicestershire suburb of Leicester in the Soar valley between Leicester and Market Harborough, is supplied by Severn Trent Water from the Permo-Triassic Sherwood Sandstone Aquifer and Keuper Marl of south-east Leicestershire. Boreholes in the Soar valley and the south Leicester basin tap the productive Triassic Bunter and Keuper Sandstone aquifer, which underlies the flat Soar valley floor and the south Leicester suburbs. Severn Trent also distributes blended Elan Valley and Rutland Water supply through the Leicester network for supplementation. At 241.5 mg/L Oadby is substantially harder than nearby Market Harborough (212.5 mg/L) and Melton Mowbray (190.5 mg/L) to the north-east, reflecting the dominance of Triassic sandstone and Keuper Marl evaporite groundwater in the south Leicester supply zone rather than the Jurassic limestone-fed supply that characterises north-east Leicestershire. The TDS of 688.9 mg/L (ratio 2.85) confirms a significant calcium sulphate contribution from the Keuper Marl evaporite beds.

The Permo-Triassic Sherwood Sandstone and Keuper Marl (Mercia Mudstone Group) beneath south-east Leicestershire dissolve calcium carbonate from sandstone cement and calcium sulphate from Keuper Marl gypsum and anhydrite interbeds, producing hard groundwater enriched in both carbonate and non-carbonate hardness. The Keuper Marl evaporite contribution explains the elevated TDS at 688.9 mg/L — far above what Jurassic limestone groundwater alone would produce for a given hardness level. Oadby's Triassic sandstone supply character distinguishes it clearly from the Jurassic limestone supply chemistry of Market Harborough and Melton Mowbray.

At 241.5 mg/L Oadby's water is hard and limescale is a persistent household concern in one of Leicestershire's most prosperous suburbs. Kettle elements should be descaled monthly with a concentrated citric acid solution. Shower screens and bath surfaces accumulate a calcium–sulphate crust that benefits from fortnightly white vinegar treatment. Washing-up liquid must be used generously. Combi-boilers face elevated scaling risk and need inline magnetic scale inhibitors and annual engineer servicing. Oadby's attractive University of Leicester campus and residential tree-lined avenues stand in contrast to the hard Triassic sandstone water supply flowing from every household tap.