Portadown Water Hardness & Quality Report (2026)

Portadown, in the Armagh City, Banbridge and Craigavon district of Northern Ireland on the River Bann, is supplied by NI Water from Lough Neagh — Britain and Ireland's largest lake — via the Dunore Point Water Treatment Works on the southern Lough Neagh shore. Lough Neagh collects water from the five major rivers draining the central Ulster basin, including the Upper Bann which flows through Portadown into the lake. The Lough Neagh catchment drains the Antrim Basalt Plateau to the north-east — the extensive Palaeogene basalt lava flows of the Antrim Hills — and the Sperrin Mountains granite and Dalradian schist country to the west. These are all calcium-poor rock types, producing inherently soft water that fills Lough Neagh. NI Water treats the Lough Neagh surface water at Dunore Point and distributes throughout mid-Ulster.

Portadown's soft water — 80 mg/L (5.6°Clark) — reflects the Antrim Basalt and granite catchments of Lough Neagh in NI Water's mid-Ulster distribution zone. The Drinking Water Inspectorate (DWI) for Northern Ireland classifies this supply as soft.

Limescale is very minor in Portadown. At 80 mg/L, limescale builds slowly — kettles need descaling every two to three months. Combi-boiler heat exchangers accumulate minimal deposits; annual servicing is routine. Showerheads and taps remain largely clear. Washing-up liquid lathers well with the soft Lough Neagh supply. Limescale is not a significant domestic concern for Portadown households on the NI Water Lough Neagh supply.