Dalkeith Water Hardness & Quality Report (2026)

Scottish Water supplies Dalkeith, the market town and administrative centre of Midlothian south-east of Edinburgh — dominated by Dalkeith Palace (now let to Restoration Hardware as a public park) and the confluence of the North Esk and South Esk rivers — from Gladhouse Reservoir in the Moorfoot Hills south of Edinburgh, treated at Glencorse Water Treatment Works near Penicuik. At 79 mg/L (5.5°Clark), Dalkeith's water is soft — virtually identical to neighbouring Mayfield (78 mg/L), confirming both communities share the same Moorfoot Hills reservoir supply zone and the same soft upland water quality.

Gladhouse Reservoir is impounded on the South Esk in the Moorfoot Hills — upland Silurian and Ordovician greywacke and shale country at the southern edge of Midlothian. These ancient compacted sedimentary rocks are impermeable and calcium-poor, producing naturally soft, low-TDS catchment water. Scottish Water routes this supply northward to Midlothian communities via the Glencorse treatment works, producing 79 mg/L with TDS 181.2 mg/L at Dalkeith — characteristic of the soft Moorfoot Hills reservoir supply throughout the south Edinburgh and Midlothian distribution zones shared by Dalkeith, Mayfield, Newtongrange, and Bonnyrigg.

At 79 mg/L, Dalkeith'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 sensible precaution. Washing-up liquid lathers well at everyday quantities. Taps and shower heads remain relatively scale-free with only occasional maintenance. In older properties, residents should briefly run the cold tap before drinking, as soft water can be mildly corrosive to lead or copper plumbing — standard Scottish Water guidance throughout the soft Moorfoot Hills supply zone of Midlothian.