Andover Water Hardness & Quality Report (2026)

The Andover area's water supply is managed by South East Water, a utility serving over 2 million residents across Hampshire, West Sussex, and Kent. The primary source is groundwater drawn from boreholes that tap into the vast chalk aquifer located beneath the South Downs. Key abstraction points are situated in the Test Valley, near Andover. Treatment facilities, including the Andover Water Treatment Works, filter, chlorinate, and adjust the pH of the raw groundwater before it enters the extensive distribution network. The aquifer itself is part of the thick Cretaceous Chalk sequence, with the Hampshire Avon and Upper Test watersheds acting as crucial catchment areas where precipitation replenishes the underground supply.

The water originates from the Upper Chalk Group, a geological formation dating back to the Cretaceous period. This expansive aquifer consists of porous limestone, characterized by fissures and flint layers, which has absorbed significant mineral content as groundwater has percolated through it over millennia. The chalk bedrock is rich in calcium carbonate, and as water flows through this fissured limestone, it dissolves substantial amounts of calcium and magnesium. This natural process is the reason behind the characteristically hard water supply found throughout this region of the UK, typical of chalk areas in southeastern UK.

Homeowners in Andover will likely notice the effects of this hard water, particularly the buildup of limescale in appliances like kettles, boilers, and showerheads. This not only reduces their efficiency and increases energy consumption but can also shorten the lifespan of dishwashers and washing machines due to mineral deposits. You might find that soap doesn't lather as easily, requiring more detergent for cleaning. While regular descaling with common household agents like vinegar or citric acid can help manage scale, installing a water softener is often recommended for these hard water zones. This will help prevent scaling, improve soap performance, and extend the life of your household equipment. South East Water ensures the water quality meets stringent UK standards, with pH levels typically between 7.2 and 7.6, which helps prevent pipe corrosion.