E.coli found in 5% of private water supplies, EPA warns

More than a quarter of small private supplies were not monitored by local authorities

One in 20 private water supplies were found to be contaminated with E.coli bacteria in 2020, threatening the health of thousands of people, the Environmental Protection Agency has warned.

Its annual report on private drinking water supplies also shows more than a quarter of small private supplies serving national schools, food businesses, nursing homes, pubs, hotels, creches and B&Bs were not monitored by local authorities in 2020.

More than a million people in the State, who are based mostly in rural areas, get water from private sources. Drinking water is provided by more than 380 group water schemes set up by community groups to some 200,000 people, while more than 1,700 small private supplies to commercial premises and schools provide water to staff, customers and service users on a daily basis.

Meeting E.coli standards is a basic requirement of safe drinking water, the report on private group schemes and small private supplies underlines – yet 20 of the 380 private group schemes and 49 of the 1,225 small private supplies monitored were found to have E.coli contamination.


These failures “are of significant concern and put the health of the consumer at risk”, it warns.

"Consumers should expect, as a minimum, that their water is safe to drink. However, compliance with the E.coli standard is not as good as it should be for water from private group water schemes and small private supplies," warned Dr Tom Ryan, director of the EPA's Office of Environmental Enforcement.

“It is essential that works to improve water quality are carried out as soon as possible to eliminate the serious risks to people’s health,” he said. “Water suppliers are obliged to make sure drinking water is clean and wholesome for consumers.”

THM exposure

The report also highlights problems with trihalomethanes (THM) arising in many supplies. They are a byproduct of chlorine disinfection and are formed where there is an excess of organic matter in the water source. “Water suppliers should keep THM levels within the drinking water standards to avoid any possible health impacts from long-term exposure,” it says.

A total of 22 (7 per cent) private group schemes failed to meet the THM standard, including seven schemes that the European Commission identified as being of particular concern.

Programme manager of the EPA's Office of Environmental Enforcement Noel Byrne said failure to monitor premises – involving 490 schemes in total – was due to difficulties in accessing premises during Covid-19 restrictions and that monitoring levels had improved since.

“However, it is vitally important that local authorities ensure all water supplies are monitored annually to provide assurance to consumers that their drinking water is safe,” he added.

To address ongoing failures in drinking water quality due to infrastructure deficiencies, the Department of Housing and Local Government is making funding available through its rural water programme. Upgrade works “should be progressed without delay at those private group water schemes, which have been identified as a priority, to improve the drinking water quality of these supplies”, he added.

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times