Well water treatment in Co. Limerick

Private wells in Co. Limerick

The 2022 Census counted 7,878 households in Limerick city and county on a private well or other private supply, 10.3% of homes. Another 7,799 are on a group water scheme, public or private. The share on private supplies is highest in the Adare-Rathkeale area, at 29.0% of homes, then 20.1% around Newcastle West and 18.5% around Cappamore and Kilmallock, where group schemes serve another 23.2%. In the city districts it's under 2%.

Nobody monitors a household well for you. It's classed as an exempted supply, so testing it and treating it is down to the owner, and the EPA advises a test at least once a year, ideally after wet weather. That's why every system we fit in Limerick starts with a lab report.

What's usually in a Limerick well

Hard water across most of the county

Limerick groundwater is shaped by limestone, and the Geological Survey of Ireland (GSI) found hard, calcium bicarbonate water through most of the county. Around Croom and Fedamore it measured 370 to 430 mg/L, which is very hard. East Limerick ran 240 to 370 mg/L, Bruree 285 to 340 mg/L and Newcastle West 259 to 273 mg/L. Softer water turns up in the sandstone and shale uplands of the west, south-east and south-west.

Iron and manganese in the west

Iron is the main natural problem. The GSI found that a high proportion of wells in the Namurian rocks of west Limerick have high iron, and to a lesser extent manganese. The muddy limestones may have high iron too, and iron can be a problem in the sandstone of the Bruree area. You see it as orange or brown staining on sinks and toilets, black specks and blocked filters.

Rotten-egg smell near the estuary

On the Shannon Estuary side around Askeaton, the GSI says iron and manganese frequently swing between zero and more than the EU limits, and hydrogen sulphide, the rotten-egg smell, can often reach unacceptable levels. It expects the limestone water there to be 300 to 450 mg/L, though that's an estimate, not a measurement.

Bacteria and nitrate

The GSI names faecal bacteria and nitrate as the main problems caused by people. Group scheme sources were poorer than public supplies, with faecal bacteria in most of them a concern, and many group scheme wells sit close to septic tanks or farmyards. Mean nitrate was above 25 mg/L in 8 of 69 public and group scheme sources, with peaks over 50 mg/L in 3. You can't see, smell or taste either, so a lab test is the only way to know. See bacteria in well water.

What we usually fit in Limerick

Most Limerick wells need the core line below, 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, which also deals with the rotten-egg smell and stops iron fouling the softener.
3. Water softener for the hard limestone water. In the softer western uplands it may not be needed.
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, and the stage that takes out nitrate if your report shows it.

On mains water and only bothered by limescale? See our water softener page for Co. Limerick instead.

The well grant in Limerick

Limerick City and County Council runs the grant for individual water supplies, and it gives filtration or UV treatment as examples of what it covers. Check the council's current conditions before any work starts, then bring it your lab report and our itemised quote. We'll tell you exactly which tests to ask the lab for: iron, manganese, hardness, pH, nitrate, E. coli and coliforms at the very least.