Well water treatment in Co. Kildare

Private wells in Co. Kildare

Kildare is mostly on mains, but not everywhere. The 2022 Census counted 5,030 households on a private well or other private supply, 6.1% of the county, and another 2,879 on a group water scheme. The share is highest around Athy (18.9%) and Clane (11.2%), and lowest around the bigger towns: 1.7% in the Newbridge area, 0.7% in Celbridge and 0.1% in Leixlip.

If you're on a well, no one monitors it for you. Household wells are classed as exempted supplies, so testing and treating the water is down to the owner, and every system we fit in Kildare starts from a lab report.

What's usually in a Kildare well

Hard water across the plains

The flat centre and west of the county sit on Carboniferous limestone, and around Athy, Monasterevin and Osberstown it's karst. The Geological Survey of Ireland (GSI) has no county-wide hardness figures for Kildare, but the Curragh Camp boreholes in the Curragh gravels give hard to very hard water, 250 to over 350 mg/L. For the Naas limestone it has no measurements and expects hard water by comparison with similar rock. Expect scale on kettles, immersion elements and shower heads.

Iron, manganese and rotten eggs in the north

In the Calp limestone of the northern lowlands, the GSI says high iron, manganese and hydrogen sulphide are common and cause considerable problems for people on private wells. It puts this mostly down to natural iron sulphide in the shalier rock and slow-moving groundwater. You'll see orange or brown staining and black specks, or notice a rotten-egg smell at the taps.

Softer, slightly acidic water in the east

The hillier east of the county, in the Wicklow foothills, and the Chair of Kildare are older Ordovician and Silurian rock, and the southern tip of the county is Leinster granite. In the east Kildare uplands the GSI found slightly hard water, 100 to 150 mg/L, with very low alkalinity and a pH mostly below 7, though not below 6. Water like that can slowly eat copper pipe, so watch for blue-green stains on sinks and baths.

What we usually fit in Kildare

On the limestone of the centre and west, the line usually runs in this order, with stages left out if the report doesn't need them:

1. Sediment filter to protect everything after it.
2. Iron and manganese filter, with catalytic carbon where there's a rotten-egg smell, ahead of the softener so it doesn't foul.
3. Water softener for the hardness.
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.

In the east Kildare uplands it's different: pH correction may be needed ahead of the iron filter, and a softener is often not needed. On mains water and only bothered by limescale? See our water softener page for Co. Kildare instead.

The well grant in Kildare

Kildare County Council's Rural Water Services runs the domestic well grant, on 045 980361 or ruralwater@kildarecoco.ie. To qualify, you have to show that the water has been tested and fails the quality standards, or that the well doesn't give enough water, so the lab report comes first. Bring it to the council with our itemised quote, and check the current terms 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. More in our well grant guide.