Wallington Water Hardness & Quality Report (2026)

The water serving Wallington is supplied by Affinity Water, a utility operating in South East England. This supply originates from groundwater, drawn from boreholes tapping into a vast chalk aquifer system beneath the Chiltern Hills and North Downs. These sources feed into the London Basin aquifer, a significant underground reservoir. The water undergoes treatment at facilities like the Baldock/Letchworth Treatment Works before distribution to residents in the London Borough of Sutton and surrounding areas. Affinity Water manages a complex network to ensure a consistent supply for this densely populated region.

The underground water originates from Cretaceous-age chalk formations, a type of porous limestone prevalent in the Chiltern Hills and North Downs. As water filters through these geological layers, it naturally dissolves substantial amounts of calcium and magnesium minerals. This process, occurring within the London Basin aquifer, is the primary reason for the water's characteristically very hard profile. The chalk's high mineral content, typical of the region's geology, directly influences the water chemistry before it even reaches the treatment works.

This very hard water can lead to noticeable limescale accumulation on household surfaces and inside appliances. You'll likely find it in kettles, boilers, washing machines, and on fixtures like taps and showerheads, potentially reducing the efficiency and lifespan of heating systems. Many residents opt for water softeners to combat these effects, though regular descaling with vinegar or the use of magnetic descalers are also common strategies. Installing a water softener is often recommended to protect appliances and improve overall performance. The tap water, however, meets all UK Drinking Water Inspectorate standards and is confirmed safe.