Maltby Water Hardness & Quality Report (2026)

Yorkshire Water supplies Maltby, a former colliery town in the Metropolitan Borough of Rotherham on the eastern fringe of South Yorkshire. Maltby sits directly on the Magnesian Limestone escarpment east of the coalfield — the Permian Zechstein limestone ridge that runs north–south through East Yorkshire and South Yorkshire — supplied via Yorkshire Water's regional network with a blend of Pennine reservoir supply and Magnesian Limestone groundwater. At 182.5 mg/L (12.8°Clark), Maltby's water is moderately hard — harder than many inland South Yorkshire towns, reflecting the greater proportion of Magnesian Limestone groundwater in this eastern supply zone.

The Magnesian Limestone (Permian Zechstein) forms the ridge on which Maltby stands, a distinctive pale dolomitic limestone containing both calcium and magnesium in its lattice. Groundwater circulating through this porous limestone aquifer dissolves both calcium and magnesium carbonate and sulphate, producing moderately hard to hard water with elevated magnesium relative to inland Yorkshire supplies. The Pennine reservoir component — drawn from soft upland catchments further west — dilutes this groundwater to moderate hardness levels in the blended supply reaching Maltby.

At 182.5 mg/L, limescale is a noticeable domestic concern in Maltby. Kettles benefit from descaling every four to six weeks to maintain element efficiency. The combi-boiler should be fitted with a scale inhibitor and serviced annually. Washing-up liquid performs adequately at normal quantities. Taps and shower heads develop moderate limescale deposits over a few weeks; a monthly wipe with white vinegar or a proprietary descaler keeps fittings clean. The moderately hard water reflects Maltby's location on the Magnesian Limestone belt — a distinctive geological feature that sets east South Yorkshire apart from the soft Pennine supply zones to the west.