As many as 1,000 private wells in Mayo could be contaminated with dangerous bacteria such as E coli, putting those who drink from them, especially children and the elderly, at risk of picking up a potentially very serious illness called VTEC.
The warning on the safety of private wells came this week from the Environmental Protection Agency, amidst growing concerns about the increasing number of VTEC cases being reported by the HSE.
The EPA said there are more than 3,200 private wells registered in Mayo and as many as 30 per cent of those well - or 1,080 - could be contaminated with dangerous strains of bacteria.
They are now urging private well owners to have their wells tested to ensure they are safe to drink from.
“The Health Service Executive has found a growing number of cases of a particularly serious form of E coli, called VTEC, in wells nationwide,” explained David Flynn, programme manager with the agency.
“People treated for VTEC are four times more likely to have consumed untreated water from a private well.”
Dr Una Fallon, a public health specialist with the HSE and the chair of the HSE National Drinking Water Group, said there has been a “dramatic increase” in the number of cases of VTEC in recent years.
“VTEC is a nasty water borne illness and cases have been linked to contaminated wells,” she outlined.
“VTEC infection is most common in children and, in up to eight per cent of cases, patients go on to develop serious kidney complications. These can, on rare occasions, prove fatal,” she warned.
Mr Flynn stressed that just because water comes from a well or spring does not mean it is ‘pure’ and therefore safe to drink.
“That is not necessarily the case,” he said. “We estimate that up to 1,080 private wells in Mayo are contaminated with human or animal waste and this can cause a significant threat to peoples’ health. ”
He also warned householders using a private well that while they themselves may develop an immunity to the bacteria in their well, visitors to their homes, particular children and the elderly, are “at risk of getting very sick”.
Ireland has the highest incidence of VTEC in Europe, according to the HSE.
Since 2011, they have reported a doubling of the number of VTEC cases in Ireland. There were 704 cases of the illness in 2013.
Animals, particularly cattle, are the main source of VTEC.
The EPA is urging well owners to visit its website and carry out a short assessment, which will help them determine whether or not their well is safe.
Dr Flynn said the key message to well owners is to get their water tested.