Fareham Water Hardness & Quality Report (2026)

Southern Water provides the mains water supply to Fareham, drawing from groundwater boreholes within the Hampshire Basin. This supply originates from the Cretaceous Chalk Group aquifer, a karstic limestone formation where rainwater dissolves calcium and magnesium from the rock. Water infiltrates this permeable chalk, which lies above less permeable Gault Clay in the Hampshire Downs, concentrating mineralisation. Treatment occurs at borehole sites, involving filtration, disinfection, and pH adjustment. The Southern Water network serves Fareham and adjacent Portsmouth Water zones, sometimes blending supplies.

The groundwater's journey through the porous Chalk Group is key to its character. This limestone is rich in calcium carbonate, and as water percolates through it, minerals are dissolved. This natural process is typical of limestone terrains in southeastern England. While underlying geology includes the Selborne Gravel and London Clay, the Chalk Group is the primary influence, imparting a high mineral content and leading to the water's hard nature. This contrasts with areas where water might flow over less soluble rock types.

Homeowners in Fareham will likely notice significant limescale buildup in appliances like kettles, boilers, and washing machines, as well as on showerheads. This scale reduces efficiency and can shorten the lifespan of these devices. You might see white deposits and clogged pipes. Mitigating these effects can involve regular descaling with household acids like vinegar or citric acid, or the installation of a whole-house water softener. Southern Water notes that water quality meets UK standards, with low lead and copper levels detected at cold kitchen taps. Avoid using hot or bathroom taps for drinking water.