Cookstown Water Hardness & Quality Report (2026)

Northern Ireland Water supplies Cookstown, the mid-Ulster market town in County Tyrone — a planned Plantation town with one of the longest main streets in Ireland (reaching nearly two kilometres in a straight line), set between the Sperrin Mountains to the north and the Lough Neagh basin to the south — from Lough Fea Reservoir on the Sperrin Mountains upland in County Tyrone, treated at Lough Fea Water Treatment Works. At 50.5 mg/L (3.5°Clark), Cookstown's water is soft — consistent with the impermeable Dalradian Metamorphic quartzite, schist, and psammite of the Sperrin Mountains that contribute almost no calcium to the Lough Fea reservoir catchment.

Cookstown draws supply from Lough Fea Reservoir in the Sperrin Mountains — a high upland landscape of Dalradian Metamorphic quartzite and psammite (the ancient metamorphic rocks that form the Sperrins ridge) with peat blanket moorland, yielding low-mineralisation soft water with almost no calcium. The result is 50.5 mg/L with TDS 88.4 mg/L — soft water characteristic of the NI Water mid-Ulster Sperrin supply tier at Cookstown, Magherafelt, and Dungannon in the same Sperrin Mountain reservoir supply zone.

At 50.5 mg/L, limescale is a minimal household concern in Cookstown. Kettle descaling once every two to three months is typically all that is required. The combi-boiler has very low scaling risk. Washing-up liquid lathers readily with small quantities. Taps and shower heads accumulate very little limescale; a quarterly wipe keeps fixtures clean. In older Cookstown properties with lead service pipes, residents should follow NI Water's precautionary advice to run the cold tap briefly before use, as soft low-TDS water has increased plumbo-solvent potential across the soft NI Water Tyrone supply zone.