Farnham Water Hardness & Quality Report (2026)

Farnham in Surrey, South East England, gets its water from South East Water, a regional supplier. The primary source is groundwater drawn from boreholes that tap into the Chalk aquifer beneath the North Downs. Key abstraction points include the Farnham and Aldershot boreholes. After treatment at facilities like the Farnham Water Treatment Works, which involves processes such as aeration, filtration, chlorination, and fluoridation, the water is distributed to the area's residents. The watershed consists of the permeable Chalk outcrop of the Hog's Back and North Downs, which feed the confined aquifer supplying Farnham.

The area's geology is defined by the South East England Chalk aquifer, a Cretaceous-period Chalk formation composed of porous white limestone with flint nodules. This karstic rock is part of the Northern and Southern Downs aquifer system. As rainwater percolates through the fissured Chalk, it dissolves significant amounts of calcium carbonate and magnesium from the rock matrix. This natural process, characteristic of karstic carbonate terrains, results in a hard water supply with a high mineral content, shaped by the water's prolonged underground journey.

Homeowners in Farnham will likely notice limescale buildup on appliances like kettles, boilers, and showerheads, which can decrease their efficiency and shorten their lifespan. Dishwashers and coffee makers may experience clogged heating elements, and bathroom fixtures can develop stubborn deposits. While regular descaling with household solutions like vinegar or citric acid is a good practice, and cleaning heating systems annually is advised, installing a water softener is strongly recommended. This can help reduce soap inefficiency, prevent staining, and minimize wear on household appliances.