Carrickfergus Water Hardness & Quality Report (2026)
Water Hardness
8.2°Clark11.7°fH6.5°dH
Source
reservoir
pH Level
7.7
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
249.6 mg/L
Est. Daily Cost
£0.26
energy & soap waste
Source: DWI Data Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Carrickfergus, your appliances are currently losing 16% efficiency due to mineral buildup.
| Appliance | In Carrickfergus | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5.8 yrs | 8.5 yrs | -32% |
| Washing Machine | 9.3 yrs | 12 yrs | -22% |
| Water Heater | 10.9 yrs | 15 yrs | -27% |
Regional Water Comparison
How Carrickfergus compares to its nearest neighbours
| City | Hardness | Clark° | Risk | Source |
|---|---|---|---|---|
| ▶ Carrickfergus, Northern Ireland | 116.5 mg/L | 8.2° | 🟡 Moderately Hard | reservoir |
| Holywood, Northern Ireland | 154.5 mg/L | 10.8° | 🟠 Hard | reservoir |
| Newtownabbey, Northern Ireland | 155 mg/L | 10.9° | 🟠 Hard | reservoir |
| Dundonald, Northern Ireland | 98 mg/L | 6.9° | 🟡 Moderately Hard | reservoir |
| Larne, Northern Ireland | 59.5 mg/L | 4.2° | 🟢 Soft | reservoir |
National Benchmark
How Carrickfergus compares to the United Kingdom average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Carrickfergus | 116.5 mg/L | 🟡 Low |
| United Kingdom National Avg | 183 mg/L | 🔴 High |
| Livingston Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Carrickfergus's Water Unique?
Local geology and source profile
Carrickfergus, the historic Norman castle town on the north shore of Belfast Lough in Mid and East Antrim, is supplied by NI Water. The supply for the north Antrim coast and east Antrim corridor comes primarily from Woodburn Reservoirs in the Antrim Plateau hills above Carrickfergus, and from Lough Mourne near Larne — upland catchments on the Antrim Basalt Plateau and its glacial drift overburden. Water is treated at Woodburn Water Treatment Works before distribution to Carrickfergus, Larne and the east Antrim coast. The Antrim Basalt Plateau is a vast Palaeogene lava sequence of Plateau Basalt and interbasaltic beds that weathered under a warm tropical climate into bauxite-type iron-rich soils, producing naturally soft surface runoff with relatively low dissolved mineral content.
The Antrim Basalt Plateau is one of the largest exposed lava fields in Europe, and its silica-rich, aluminium-dominated weathering products contribute minimal calcium carbonate to surface water. Reservoir catchments on the basalt plateau produce moderately soft water, with the modest 116.5 mg/L hardness in Carrickfergus likely reflecting slight calcium pickup from glacial till deposits (containing limestone erratics) in the lower Woodburn catchment and from the distribution network. The TDS of 249.6 mg/L is low, consistent with a predominantly basalt-derived surface-water supply.
At 116.5 mg/L Carrickfergus has moderately soft water — comparable to many north-west England towns and considerably softer than most of southern England. Limescale accumulates only gradually. Kettles benefit from descaling every six to eight weeks using a citric acid descaler. Shower screens remain relatively clean and need only occasional treatment with white vinegar. Washing-up liquid lathers well. Combi-boilers and white goods face modest scaling risk. Carrickfergus' medieval harbour heritage and its prominent Norman castle draw visitors, and the town's soft water supply is a day-to-day practical benefit for its residents.
Geology & Source: Supplied by NI Water from Lough Mourne and the Woodburn Reservoirs in County Antrim — soft upland basalt and drift catchments of east Antrim — produces moderately soft water at 116.5 mg/L (8.2°Clark).