Lancing Water Hardness & Quality Report (2026)

South East Water supplies Lancing, a coastal town in West Sussex on the English Channel coast. Supply is drawn from deep boreholes in the South Downs Chalk aquifer and surface water from the River Adur catchment, treated at Falmer Water Treatment Works and other Sussex facilities before distribution across the coastal strip between Worthing and Brighton. At 322.5 mg/L (22.6°Clark) and a TDS of 938.4 mg/L, Lancing's water is among the hardest on the south coast — a level reflecting deep, confined chalk aquifer water with extremely long residence times beneath the coastal plain.

The South Downs rise steeply north of Lancing and are underlain by some of the thickest sections of Upper Cretaceous Chalk in England. Groundwater infiltrating the chalk from the downland crest and dip slope percolates through hundreds of metres of porous rock before emerging at deep boreholes or spring lines at the coastal foot. This extended underground transit maximises calcium carbonate dissolution, and the confined nature of the chalk beneath the coastal Quaternary deposits further concentrates dissolved minerals, producing near-1000 mg/L TDS water that delivers hardness at the extreme end of the South East dataset.

Limescale is a severe and relentless challenge in Lancing. Kettles must be descaled every one to two weeks to prevent rapid element degradation. Combi-boilers face a very high risk of premature failure without a fitted scale inhibitor replaced annually and regular professional servicing of the heat exchanger. Washing-up liquid requires substantially more product than usual to achieve any lather in this extremely hard water. Taps, shower screens, and basin mixers must be descaled weekly to prevent permanent hard-water staining, and a whole-house water softener is essential for long-term protection of all appliances, plumbing, and the boiler.