Hetton-Le-Hole Water Hardness & Quality Report (2026)

Northumbrian Water supplies Hetton-le-Hole, a former colliery town in the East Durham Coalfield in the City of Sunderland, from Kielder Reservoir transferred via the Tyne–Wear inter-basin transfer and blended with treated River Wear catchment supply, treated at Wearmouth Water Treatment Works. At 87 mg/L (6.1°Clark), Hetton's water is soft — considerably softer than might be expected from a town in the Permian Magnesian Limestone east Durham Coalfield — reflecting the dominance of the Kielder aqueduct supply that keeps Sunderland and Wearside water quality consistently soft.

Hetton-le-Hole sits in the East Durham Coalfield plateau, where the Permian Magnesian Limestone (Zechstein Dolomite) lies beneath the glacial till that caps much of east Durham — a limestone formation that naturally produces very hard, sulphate-rich groundwater. However, Northumbrian Water's Kielder aqueduct supply effectively overrides the local geological influence, delivering very soft Border Moors granite and greywacke catchment water via the north-east aqueduct system to the Wearside distribution zone. The resulting 87 mg/L with TDS 198.2 mg/L is the soft Kielder-dominated character of the Sunderland and south Tyneside supply.

At 87 mg/L, Hetton's soft water is comfortable for domestic use with minimal limescale demands. Descaling the kettle every two to three months is typically adequate. The combi-boiler benefits from a standard scale inhibitor as a precaution. Washing-up liquid lathers well with everyday quantities. Taps and shower heads remain relatively clean with only occasional maintenance. The soft Kielder supply creates an interesting contrast between Hetton's soft tap water and the naturally very hard Magnesian Limestone groundwater that lies in the rocks directly beneath the town.