Irish Water knew of water contamination risk in Co Mayo

The Environmental Protection Agency (EPA) warned Irish Water about risks of cryptosporidium contamination at a Co Mayo water scheme last year, it has emerged.

A boil water notice, imposed on September 2nd, continues to be in operation for 46,500 people who are supplied by the Lough Mask Regional Water Supply Scheme, after the supply tested positive for cryptosporidium, a parasite that causes gastrointestinal illness.

The EPA carried out an audit of the water scheme on September 6th. That report has not yet been published.

However, in a previous audit, in May 2015, the agency warned there were significant operational issues at Lough Mask treatment plant that presented a risk of “filter breakthrough”, which could result in cryptosporidium entering the water supply.

It said controls and operations of the filters at the plant required urgent attention.

In a statement issued on Monday, Irish Water said the most recent EPA report stated that significant improvements to filtration management and control had been made since May 2015.

It also stated there was no evidence of filter breakthrough in the two weeks prior to the cryptosporidium detection.

“All recommendations made in the report are being actioned by the incident management team,” the statement said.

Sampling

Irish Water said that since the parasite was detected, daily sampling at the water source, at the treatment plant and on the network had not identified any further presence of cryptosporidium.

However, it said that, in the interests of public safety, testing will continue and the boil notice will remain in place.

A spokeswoman said, so far, there had been no confirmed cases of people contracting gastrointestinal illness, but the incubation period for cryptosporidium could last up to 28 days. She said a further update would be issued later in the week.

“Throughout this period people are urged to continue to boil water for drinking and before use in food preparation,” she said.

Residents in all major towns in the south of the county, including Castlebar, Westport, Claremorris, Ballinrobe, Ballyhaunis and Knock, are affected, as are the communities of Ballindine, Balla, Kilmaine, Cong and their associated hinterlands.

Some group water schemes are also covered by the boil water notice.