Welling Water Hardness & Quality Report (2026)

Welling, in the London Borough of Bexley in outer south-east London between Bexleyheath and Plumstead on the fringe of the Thames valley, is supplied by Thames Water from the River Thames storage reservoir system supplemented by North Downs Chalk Aquifer groundwater from chalk boreholes in the north Kent and Surrey chalk country. Welling's outer south-east London Bexley position places it in the Thames Water supply zone that blends Thames reservoir supply with significant North Downs chalk groundwater from the Kent chalk — the same Cretaceous Chalk of the North Downs that produces very hard water across the south-east London supply zone. Thames Water distributes through the outer south-east London Bexley network, delivering moderately hard chalk-influenced supply to Welling.

Welling's hard water — 235.5 mg/L (16.5°Clark) — reflects the North Downs Chalk Aquifer influence on the outer south-east London Bexley supply zone. The Drinking Water Inspectorate (DWI) classifies this supply as hard.

Limescale is a persistent household challenge in Welling. At 235.5 mg/L, limescale forms in kettles within two to three weeks and monthly descaling is advisable. Combi-boiler heat exchangers accumulate deposits steadily — annual boiler servicing and an in-line scale inhibitor are recommended. Showerheads, taps, and shower screens develop regular deposits. Washing-up liquid lathers poorly. Using Calgon monthly in the washing machine and maintaining a regular descaling routine is important limescale management for Welling households.