Camborne Water Hardness & Quality Report (2026)

South West Water supplies Camborne in west Cornwall, drawing from a blend of surface water reservoirs and groundwater sources across the county, treated at Boscathnoe Water Treatment Works near Penzance before distribution to the Camborne and Redruth area. The comparatively high hardness of 224.5 mg/L (15.7°Clark) for a Cornish town reflects a supply incorporating groundwater from calcareous contact zones and thermally metamorphosed formations within west Cornish geology, blended with surface water from mixed catchments across the wider South West Water network.

West Cornwall geology is dominated by the Carnmenellis Granite — an intrusive pluton that typically yields very soft, acidic groundwater. However, the margins of the granite are flanked by thermally metamorphosed Devonian sedimentary and calcareous skarn formations containing significant calcium carbonate. Groundwater circulating through these contact aureole zones and in Devonian limestone outliers west of Truro can acquire appreciable dissolved hardness. Blending multiple sources across the broader west Cornwall supply area produces hardness considerably higher than the granite alone would suggest, giving Camborne an unexpectedly hard supply.

Limescale is a meaningful household concern in Camborne. Kettles should be descaled monthly to maintain heating efficiency and avoid chalky deposits in drinks. The combi-boiler benefits from a fitted scale inhibitor and annual servicing to check for calcium build-up in the heat exchanger. Washing-up liquid requires slightly more product than in softer-water areas to achieve a satisfactory lather. Taps and shower heads develop noticeable limescale deposits over a couple of weeks; a fortnightly wipe with a descaling product or white vinegar is recommended to prevent hard-water staining and protect seals and valves from progressive calcium damage over time.