Sheerness Water Hardness & Quality Report (2026)

South East Water supplies Sheerness, the port and former Royal Navy dockyard town at the north-western tip of the Isle of Sheppey in Kent — a community shaped by maritime industry, the Sheerness Docks container terminal, and its distinctive position at the confluence of the Thames and Medway estuaries — from the North Downs Chalk via the Isle of Sheppey supply infrastructure, treated at Burrows Lane Water Treatment Works on Sheppey. At 307 mg/L (21.5°Clark) and a TDS of 830.7 mg/L, Sheerness's water is extremely hard — consistent with the deeply chalk-saturated supply of the North Kent chalk zone that is piped to Sheppey from the mainland chalk distribution network.

Sheerness is supplied by water pumped across from the North Kent Chalk distribution network — the same deeply mineralised chalk supply that characterises communities throughout the Isle of Thanet, Sittingbourne, and the Medway towns. The Isle of Sheppey has no independent water source; supply from the mainland North Downs chalk zone is transmitted to the island via the supply main crossing the Swale, delivering 307 mg/L with TDS 830.7 mg/L of extremely hard chalk water — consistent with the North Kent chalk belt supply character.

At 307 mg/L, limescale is an extreme and persistent household problem in Sheerness. Kettles must be descaled weekly to prevent rapid element failure. The combi-boiler faces very high risk of premature breakdown without a properly fitted, annually replaced scale inhibitor and regular professional servicing. Washing-up liquid barely lathers without very generous quantities of product. Taps, shower heads, and basin fittings develop heavy chalk encrustation within days; a weekly descaling with white vinegar or a proprietary product is essential. A whole-house water softener is very strongly recommended for all Sheerness households to protect appliances from the extreme North Kent chalk supply.