Well water treatment in Co. Monaghan

Private wells in Co. Monaghan

Monaghan is group scheme country. The 2022 Census found 9,217 households, 40.3%, on public or private group water schemes, the highest share of any county or city, and only 45.1% on public mains, the lowest. Another 3,025 homes, 13.2%, are on a private well or other private supply. That share is highest in Ballybay-Clones (19.5%), then Carrickmacross-Castleblayney (12.8%) and the Monaghan area (8.7%).

A household well is classed as an exempted supply, so nobody checks it except you. Every system we fit in Monaghan starts from a lab report.

What's usually in a Monaghan well

Hard to very hard water

The Geological Survey of Ireland (GSI) sampled 87 sources in Monaghan, private wells among them. Of those, 28% were excessively hard (over 350 mg/L), 48% hard (251 to 350), 18% moderately hard (151 to 250) and only 6% slightly hard (under 150). The softer water is in the Carrickmacross and Knockatallon/Tydavnet aquifers and the older sandstone and shale. Expect scale everywhere hot water goes.

Iron and manganese

High iron and manganese, often above the drinking water limit, are widespread and mostly natural. The GSI recorded iron up to 25 mg/L, though half the samples were at or under 0.3 mg/L, and manganese up to 3 mg/L. That's enough to stain sinks and laundry and to foul a softener.

Bacteria

Faecal coliforms turned up in 9 of the supply sources the GSI examined (26%), mostly council and group scheme sources. In the Carrickmacross karst limestone, the only karst aquifer in the county, they were found in 4 of 6 sources, including the Nafarty spring and borehole, and nitrate there runs higher than elsewhere in Monaghan. The GSI concluded that septic tanks, landspreading and farmyards all contribute. See bacteria in well water.

Natural fluoride and sulphate

Fluoride ranges from 0.04 to 3.5 mg/L, and the GSI found levels above the drinking water limit occurring naturally in the Knockatallon/Tydavnet aquifer in the north-west. Sulphate runs from 2 to 2,400 mg/L, with levels over 500 mg/L mainly in deep, high-yielding wells in the Monaghan to Clones aquifer, linked to gypsum-type beds. You can't see either, so if you're in those areas, ask the lab to include them.

What we usually fit in Monaghan

For most Monaghan wells, the line runs in this order, with stages left out if the report doesn't call for them:

1. Sediment filter to protect everything after it.
2. Iron and manganese filter, ahead of the softener so it doesn't foul.
3. Water softener sized for hard to very hard water.
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, which also brings fluoride and sulphate down in the water you drink.

On a group scheme or mains and only bothered by limescale? See our water softener page for Co. Monaghan instead.

The well grant in Monaghan

Monaghan County Council's Water Services and Rural Water Department, at MTEK 1, Armagh Road, Knockaconny, Monaghan, handles well grants, on 047 73769 or 047 73763. Get the lab report first, send it to us for an itemised quote to go with the application, and check the current terms with the council before any work starts. We'll tell you which tests to order: iron, manganese, hardness, pH, nitrate, E. coli and coliforms at the very least, plus fluoride or sulphate where they apply. More in our well grant guide.