Some 4.5% of the private wells in the country do not meet E coli standards, according to analysis by the Environmental Protection Agency (EPA).

The EPA found that out of 1,434 private wells inspected, 73 were at risk of contamination with the bacteria.

The finding was just one of those published in the Drinking Water Quality in Private Group Schemes and Small Private Supplies 2022 report, released by the EPA on Friday.

Of the 370 private group water schemes monitored in 2022, 4.1% (14) were found to not meet E. Coli standards. The EPA said that this indicates that the water supply had not been properly disinfected.

The failure of these disinfection systems put the health of approximately 5,500 people that use these drinking water supplies at risk, the agency maintained.

Meeting E coli standards is a basic requirement in the provision of safe drinking water.

Private wells

The EPA also highlighted issues where small private wells are registered with local authorities, but are not being monitored.

It found that that 266 (16%) of the 1,700 small private supplies registered were not monitored at all and that, overall, private drinking water quality is not as good as public water quality.

The EPA has highlighted its concerns regarding private water supplies.

However, the trend is improving, as the 84% of registered small private supplies which were monitored in 2022 being an increase when compared with 75% in 2021.


The EPA pointed out that drinking water is provided to approximately 200,000 people across rural communities in Ireland by over 380 group water schemes.

In addition, many rural commercial and public activities such as schools, creches, nursing homes, pubs and restaurants have their own drinking water wells.

There are 1,700 small private supplies registered with local authorities, but the total number of small private supplies remains unknown, as many suppliers haven’t registered their supply, the EPA explained.


The EPA also highlighted that in 2022, 16 private group schemes supplying 14,000 people failed the standard for trihalomethanes (THMs).

THMs are formed when natural organic matter in the water source, such as vegetation, reacts with chlorine used in the disinfection treatment process. THM levels should comply with the drinking water quality standards, while ensuring that the water is fully disinfected.

Actions to prevent THM failures need to be prioritised by suppliers to protect public health, the EPA said.


Commenting on the findings of the report, director of the EPA’s office of environmental enforcement Dr Tom Ryan said: “It is a local public health concern that private drinking water quality hasn’t improved in recent years, despite the availability of public funding to support upgrades to water supplies.

“In addition, as there is no legal requirement to register private drinking water supplies, it is not possible to quantify the full extent of the risk to public health. The registration of private supplies needs to become a legally enforceable obligation on the supplier,” he said.