Well water treatment in Co. Wicklow

Private wells in Co. Wicklow

The 2022 Census counted 8,799 Wicklow households on a private well or other private supply, 16.3% of the county, and another 1,222 on a group water scheme. The share on a private supply is highest in the west and south: 37.1% of homes in the Baltinglass area and 23.8% around Arklow, against 2.3% in Greystones and 0.1% in Bray East.

A household well is classed as an exempted supply, so nobody checks it but you. That's why everything we fit on a Wicklow well is specified from a lab report.

What's usually in a Wicklow well

Soft, often acidic water

Granite forms the mountains in the middle of the county, with older sandstone and shale to the east and west. The Geological Survey of Ireland (GSI) found groundwater mainly moderately soft, averaging 50 to 100 mg/L, and as soft as 20 mg/L in the central uplands. Granite minerals are generally acidic, the GSI notes, and in the west Wicklow uplands it found a pH mostly below 7. Soft, acidic water can attack copper pipe and brass fittings, leaving blue-green stains and, in time, pinhole leaks.

Iron and manganese

The GSI calls iron and manganese a major problem in Wicklow's shale and sandstone, with iron up to 20 mg/L and manganese up to 0.75 mg/L. Its sampling was mostly of council and group scheme sources, and those over the limit included Roundwood, Kirikee, Rathdrum, Threewells, Annacurragh and Thomastown. The GSI says the rock is the cause, not pollution. Expect orange staining, black specks and a metallic taste.

Bacteria

Here the GSI did look at household wells. In 1997 it had results from 22 private wells, mostly around Brittas Bay. Four had E. coli (one cleared on re-test) and two more had total coliforms above 10 per 100 ml. Its conclusion: many wells in highly vulnerable areas carry faecal bacteria from time to time, likely from septic tanks and farmyards. See bacteria in well water.

Uranium near Baltinglass

Uranium is associated with granite. The Lathaleere public water source at Baltinglass was closed in November 2002 because of uranium in the water. That was a public supply, not a household well, but if you're in that area, ask the lab about adding uranium to your test.

What we usually fit in Wicklow

Most Wicklow wells need a different line from the limestone counties, and a softener is often not needed. In order, leaving out anything the report doesn't call for:

1. Sediment filter to protect everything after it.
2. pH correction, a vessel of neutralising mineral that lifts acidic water so it stops eating copper.
3. Iron and manganese filter, which works better once the pH is up.
4. UV disinfection if the report shows E. coli or coliforms, fitted last on the main line so the water reaching the lamp is clear.
5. Reverse osmosis at the kitchen tap for drinking water, if you want it.

The exception is around the edges of the county, where the subsoil is rich in limestone: the spring at Parkmore, near Baltinglass, measured 286 to 324 mg/L. Water from the rock around Brittas Bay can run harder too. Where the report shows hard water, a softener can go in after the iron filter. For rough figures, see what well water treatment costs.

The well grant in Wicklow

Wicklow County Council's Water and Waste Water section runs the scheme, which it calls Individual Water Grants. Its rules: the works must cost over €750, you need three quotes, and the contractor must have a C2 or tax clearance. Get the lab report first, then the quotes, and check the current terms with the council (reception 0404 20100) before any work starts. We'll tell you which tests to ask for: pH, iron, manganese, hardness, nitrate, E. coli and coliforms at the very least. More in our well grant guide.