Petersfield Water Hardness & Quality Report (2026)

South East Water serves Petersfield, Hampshire, UK, drawing its supply primarily from groundwater. The water originates from boreholes tapping the Lower Greensand aquifer, including sites like Candy Lane and Rogers Farm. Treatment takes place at the Petersfield Water Treatment Works, where processes such as aeration, filtration, chlorination, and fluoridation ensure the water meets stringent UK drinking water standards. This supply is part of South East Water's Zone 5 network, covering Petersfield postcode districts GU31 and GU32. The watershed encompasses the upper catchment of the River Rother and Western Streams, which drain the South Downs National Park.

The groundwater's journey begins as rainwater percolates through the Cretaceous Lower Greensand sandstones and underlying Wealden clays. This geology creates a productive confined aquifer, recharged by rainfall on the chalk uplands of the South Downs. The water picks up significant amounts of calcium and magnesium as it passes through limestone lenses and chalky overburden, naturally resulting in hard water. Long residence times within the aquifer enhance this mineral content, as there's little dilution from surface runoff. The Hampshire Downs and South East England are known for such mineralised groundwater profiles typical of confined aquifer systems.

Homeowners in areas with moderately hard water might notice limescale buildup in kettles and on faucets, along with reduced efficiency in appliances like washing machines and dishwashers. Hot water systems and boilers are particularly susceptible, as scale can insulate heating elements, driving up energy costs. Regular descaling of appliances with vinegar or citric acid can help manage this. While not strictly essential for everyone, installing a water softener is often recommended to prevent appliance damage and improve soap lathering. South East Water consistently meets Drinking Water Inspectorate standards, with routine monitoring showing typical pH levels between 7.2-7.6 and full compliance for lead and copper following pipe upgrades. Occasional iron and manganese from boreholes are managed through aeration and filtration.