Poorly constructed wells and inadequate monitoring of private water supplies is putting the health of up to one-fifth of the population at risk, the Environmental Protection Agency (EPA) has warned.
An EPA report on the quality of private water supplies found the quality of drinking water in private supplies, which are mostly sourced from wells, is poorer than that in publicly-sourced supplies, putting huge numbers at risk of consuming contaminated water.
It determined that approximately 20% of Ireland's population is supplied by private water supplies and that the risk of contaminated supplies is much higher in private supplies than public.
No testing was done on 16% of registered private supplies. Smaller schemes - those serving fewer than 50 people - are not covered by drinking water regulations and it is estimated that between 15% and 30% of these are contaminated, with two-thirds at risk of contamination.
Dr Tom Ryan, director of the EPA's office of environmental enforcement, warned that many creches, nursing homes and hotels are being served by private supplies. In fact, there are 1,700 public and commercial premises and 172,000 homes which get their water from wells.
"Where this water comes from poorly constructed wells, there is a high risk of contamination during heavy rain," Dr Ryan said.
It is worrying that many of these supplies are not being monitored, as consuming contaminated water poses a serious health risk to consumers, particularly vulnerable people such as the young or elderly.
Monitoring carried out in 2018 showed that commercial businesses and public buildings that get their water from a well or other private source are at greater risk of being contaminated than public water supplies.
More than 60 of these private supplies were found to be contaminated with human or animal waste at least once during 2018. Cases of VTEC infection – a dangerous form of E. coli, which can be contracted due to consuming water contaminated by animal waste – continued to rise with over 1,000 reported cases in 2018. Ireland continues to have the highest incidence of VTEC infection in Europe at 10 times the European average.
Andy Fanning, Programme Manager of the EPA’s Office of Environmental Enforcement warned that greater care is needed for private water supplies. He said regular testing is needed.
"With this number of reported cases of VTEC in Ireland, it is more important than ever that business owners and homeowners who use a well for their water supply, get their supply tested regularly, especially after rainfall," Mr Fanning said.
"Local authorities must ensure that supplies are registered, monitored and that action is taken by water suppliers to remedy any issues identified to make sure that public health is not being put at risk.”
Extreme weather in 2018, including the snow during Storm Emma and the summer heatwave, caused issues for those using private wells, too.
Heavy rainfall is also an issue as it can wash contamination into wells which are not properly protected. It is estimated that two-thirds of private wells are not sufficiently protected to prevent contamination.
The EPA has also criticised the monitoring of private supplies by local authorities.
Just 15 local authorities carried out audits of private supplies in 2018. The 91 audits carried out represent 3.5% of registered private regulated supplies. There are counties where boil water notices were issued where no audits were undertaken.