Warning to check if water from private wells is safe

Children, older people, and those who are immunocompromised are at increased risk of severe illness if exposed to e.coli. Stock picture: Adobe

Hotels, creches, nursing homes, and schools dependent on getting water supplied from private wells should ask whether it is “safe to drink”, according to the Environmental Protection Agency (EPA).

It comes as one in 20 supplies could be affected by e.coli bacteria found in contaminated drinking water, which is provided by “small private supplies”. According to the latest report from the EPA looking into private water supplies, there was a 95.5% compliance rate with the e.coli standard.

Out of the 1,600 systems registered with local authorities across Ireland, 67 well supplies failed the standard in 2025.

EPA programme manager Noel Byrne said there was concern that well suppliers had no legal obligation to register with their local authorities, which leads to water supplies not being sampled every year.

In Cork, for example, over 250 well supplies are monitored, whereas in Co Mayo — which has a larger rural population — there are only 20 registered supplies.

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“You can say one in 20 supplies failed to meet e.coli standards in the small private supplies,” Mr Byrne told the Irish Examiner.

“I want to say that sounds small, but actually that is not good enough. One person getting sick because they drank contaminated water is now sick for a day or so with vomiting or diarrhoea, and that can be even more serious depending on the contamination that they get.

“If a very young child or a very elderly person, or someone immunocompromised [was affected], that’s just not good enough,” he said.

Mr Byrne said people should “have the right to good quality water, particularly if they are on commercial premises and people are providing water to them and that meets standards”.

“It isn’t okay for someone to get sick and wonder what happened or how did I pick up that bug, because it can make you quite sick,” he said.

Additionally, 14 privately-run community water schemes which supply over 1,850 systems had e.coli failures in 2025. This was down by 10 when compared to 2024.

Meanwhile, more than 19,000 people receiving drinking water through the community-run supply are still seeing trihalomethanes over the regular standard.

The EPA said these numbers show the contamination in 17 private water schemes last year. This was down by two when compared to 2024. Around 370 schemes are serving 194,000 people.

Trihalomethanes are created when chlorine is used to disinfect water. These chemicals are formed when there is an excess of organic matter — such as decaying plants and algae — in the water source.

According to the HSE, the potential risk is very low over a typical lifetime of consumption. Additionally, short-term use of drinking water which exceeds guidelines is unlikely to have an impact on human health.

However, it has been highlighted that some of the individual trihalomethane chemicals could pose both short- and long-term health effects, including dizziness; fatigue; headache; sleepiness; incoordination; dull chest pain; liver damage; kidney damage; testicle damage; and skin sores.