Burnham-on-Sea Water Hardness & Quality Report (2026)

Burnham-on-Sea, the Somerset coastal resort on the Bristol Channel at the northern edge of the Somerset Levels between Weston-super-Mare and Bridgwater, is supplied by Wessex Water from the Mendip Hills Carboniferous Limestone supply network. Supply draws on chalk springs and Carboniferous Limestone groundwater from the Mendip Hills via the Cheddar Springs and Axbridge source complexes, and on surface water from the River Axe and Huntspill River channels of the Somerset Levels — partly pumped up from the Levels drainage network. Wessex Water treats the supply at Huntspill Water Treatment Works and distributes north to Burnham and the Somerset coastal plain. The Mendip limestone contribution dominates the supply hardness at 235 mg/L — from the same source system that produces Frome's very hard 252 mg/L to the east, though with more surface-water dilution from the Somerset Levels river water in the coastal blend. The TDS of 687.3 mg/L reflects Carboniferous limestone carbonate chemistry with sulphate from the Dolomitic Conglomerate formations at the Mendip margin.

The Carboniferous Limestone (Dinantian) of the Mendip Hills forms a major karst aquifer with springs at Cheddar, Wookey Hole and the Axe valley discharging hard calcium bicarbonate water at 250–270 mg/L. In the Burnham-on-Sea supply, this Mendip groundwater is blended with surface water from the Somerset Levels rivers that carry moderately hard water from the Lias and alluvial lowland catchment (150–180 mg/L), moderating the final hardness from the extreme Frome levels (252 mg/L) to 235 mg/L at the coast.

At 235 mg/L Burnham-on-Sea's water is hard and limescale is a persistent household concern. Kettles need descaling monthly with a citric acid tablet. Shower screens accumulate a calcium film requiring regular white vinegar treatment. Washing-up liquid must be used generously. Combi-boilers benefit from inline scale inhibitors and regular servicing. Burnham's traditional Somerset seaside character — the wide sandy beach, the low lighthouse and the flat Levels behind — belies the hard Mendip limestone water that flows from every household tap.