A report from the Environmental Protection Agency (EPA) on 2023 water quality has highlighted the presence of E. coli in Irish water. The report shows many private water sources are failing to meet bacterial safety standards. It also reveals that a lot of government money meant to fix these problems hasn’t been used.
What’s Happening with Private Water Supplies?
The EPA’s report on 2023 water quality says that nearly 5,000 people were in danger in 2023 because of E. coli in private drinking water supplies. This contamination occurred in ~ 1 in 20 small private water supplies and group water schemes. Places like schools, nursing homes, sports clubs, and holiday accommodations use these private supplies.
In Ireland, many people rely on these private water supplies, especially in rural areas. More than 370 group water schemes serve around 190,000 people. But there’s a problem: some of these schemes are not registered. For example, in Leitrim, only one small private supply was registered. Lack of registration leaves gaps in monitoring and safety.
The Danger of E. coli in Irish Water
E. coli is a type of bacteria that can be harmful when it’s in drinking water. It often comes from animal waste or untreated sewage. Some strains of E. coli can cause serious health problems like stomach infections, urinary tract infections, and even kidney damage. E. coli in drinking water usually means the water hasn’t been properly disinfected.
The legal limit for E. coli in drinking water is 0 per 100 ml. There is no acceptable level: any detection means the water has failed the standard and is considered unsafe to drink without treatment. One strain of particular concern in Ireland is verotoxigenic E. coli (VTEC), which can cause severe illness, especially in young children and older people. Ireland has consistently reported one of the highest rates of VTEC infection in Europe, and drinking untreated private well water is a recognised risk factor.
The EPA’s report found that 22 private group schemes failed to meet E. coli safety standards in 2023. Additionally, 71 small private supplies monitored by local authorities did not meet standards. This highlights a serious water quality problem and the need for better monitoring and maintenance.
Problems with THMs and Other Issues
Besides E. coli, the EPA report also highlighted problems with Trihalomethanes (THMs). These chemicals form when chlorine used for water disinfection reacts with organic matter. In 2023, 22 private group schemes failed to meet the legal limits for THMs, affecting around 22,000 people.
In January 2024, the European Court of Justice ruled that Ireland had not done enough to address THM compliance in some private group schemes. This ruling shows that more must be done to enforce water safety rules.
Unused Funding and the Need for Improvement
An issue mentioned in the report is that a lot of government money meant to improve private water supplies hasn’t been used. Between 2019 and 2023, €38.5 million available for upgrades went unspent. Noel Byrne from the EPA said it was disappointing that this money wasn’t used considering the water quality problems. However, he also noted that recent changes to make it easier to apply for funding are positive.
Dr Tom Ryan from the EPA said urgent action is needed to fix the problems. Compulsory registration of all private water suppliers to local authorities is essential. In the meantime, local authorities need to find and register unaccounted small private water supplies.
What the Latest EPA Figures Show
The EPA’s 2025 report shows some improvement in private group schemes. 14 private group schemes, supplying 1,854 people, failed the E. coli standard in 2025, down from 24 schemes in 2024. Compliance also increased from 93.7% to 96.2%. However, more than 40% of the schemes that failed in 2025 had also failed in 2024.
Small private supplies remain a concern. 67 small private supplies failed the E. coli standard in 2025, and registration is still not a legal requirement. Monitoring also varies widely by county: over 250 supplies are monitored in Cork, compared with just 20 registered in Mayo, despite Mayo’s larger rural population.
THMs remain an issue too, with 17 private group schemes serving 19,362 people failing the THM standard in 2025, a minor improvement on 19 schemes in 2024.
What About Household Wells?
The EPA figures above cover regulated supplies only. Household wells are exempt from the drinking water regulations, so responsibility for testing lies with the householder. The EPA advises well owners to test their water, and has cited a study finding E. coli in almost a third (29%) of Irish private wells. Contamination often has no visible sign, so laboratory testing is the only reliable way to confirm a well is safe.
Conclusion for E. coli in Irish Water
In summary, repeated E. coli failures and the unused government funding show that Ireland’s approach to managing private water supplies needs to be improved. Better monitoring can be achieved by enforcing registration of private supplies. Southern Scientific offers accredited testing for bacteria in water, which is key to identifying and correcting contamination concerns.
With over 30 years of experience, Southern Scientific is INAB accredited (registration 194T) to ISO 17025 and analyses over 10,000 drinking water samples every year. Whether you manage a group scheme, a small private supply, or a household well, our Bacteria in Water Test confirms whether E. coli is present in your supply..
