One third of private wells are contaminated by E.coli, from animal or human waste, and there is a greater risk of illness if you drink contaminated water from private wells, according to the Environmental Protection Agency (EPA). 

The EPA says the HSE is reporting a growing number of cases of VTEC – a particularly nasty form of E.coli. and says Ireland has highest incidence of VTEC in Europe. Analysis of cases shows that people treated for VTEC are four times more likely to have consumed untreated water from a private well. The EPA has developed a new assessment tool ‘Protect your Well’ and well owners are urged to use it to assess their private well and ensure they are not putting their health or the health of family and visitors at risk.  

“Lots of people assume that because their water comes from a well or a spring that it’s completely pure and safe to drink, but that is not necessarily the case,” said David Flynn, Programme Manager, EPA.

“We estimate that up to 50,000 private wells in Ireland are contaminated with human or animal waste and this can cause significant threat to people’s health. Sometimes, we find that people can develop immunity themselves, but visitors to the house, particularly children and the elderly are at risk of getting very sick.”

Dr Una Fallon, Public Health Specialist in the HSE and Chair of the HSE National Drinking Water Group said: “There has been a dramatic increase in the number of cases of VTEC (Verotoxigenic E. coli) in recent years. VTEC is a nasty water borne illness and cases have been linked to contaminated wells. VTEC infection is most common in children and in up to 8 per cent of cases patients go on to develop serious kidney complications. These can, on rare occasions, prove fatal. This is all preventable.”

Ireland has the highest incidence of VTEC in Europe, according to the EPA. Since 2011, the HSE has reported a doubling of the number of VTEC cases in Ireland (284 in 2011, 554 in 2012 and 704 in 2013). Animals, particularly cattle are the main source of VTEC and infection is spread either from direct animal contact or through contaminated food and water. Person to person spread is also common. In other countries the most common source of infection is through food outbreaks.

In Ireland, rural families are commonly affected and much of this is because of contaminated private wells. Consumers of water from private wells at much greater risk of VTEC than those who drink water from mains supplies.  It can take a long time for the bug to clear even after the child has become well.

Disinfection kills all E. coli including VTEC and, while public water supplies are disinfected, not all private wells are.

“Well owners should check their wells to ensure their health is not at risk,” said David Flynn, Programme Manager, EPA. This includes checking that there aren’t any sources of pollution entering their well and testing their water, at least once a year, ideally following heavy rain when the well is most at risk of contamination.