Irish Water cannot guarantee an end to boil water notices due to the plant in Leixlip remaining “vulnerable.”

Following the lifting of the latest notice on Tuesday, Niall Gleeson, Managing Director of Irish Water, acknowledged the impact on the 600,000 people affected, many of them residents of Lucan, Clondalkin and Palmerstown.

“The old plant at Leixlip remains vulnerable and Irish Water working with Fingal County Council will be working to minimise the risk of another boil water notice,” he said.

“If we could, we would shut down the old plant, take it off line and do all the refurbishment at once.

“This is not possible because 20% of Dublin’s water supply comes from the old plant and we do not have the spare capacity to allow this to happen.

“We will continue to monitor the plant closely.”

Irish Water has been heavily criticised for the problems experienced at the plant.

Now the Environmental Protection Agency (EPA) has recommended that Irish Water install ultraviolet treatment of drinking water at the Leixlip plant to avoid boil water notices in the future.

Ultraviolet light is used in many other countries worldwide to remove pathogens and bacteria in the water.

Irish Water has told the EPA it will report by November 30th on the likely costs and timescale for the implementation of the measure in Leixlip.

Drinking water is usually disinfected by adding chlorine at a water treatment plant, reservoir or pumping station.

Ultraviolet disinfection systems can also be used to kill pathogens and bacteria.

In a statement to Dublin Gazette, a spokesperson for the Irish Water said:

“The EPA, who are expected to publish their findings next week, were able to see the ways in which Irish Water and Fingal County Council have optimised the old plant; the additional staffing and monitoring; and daily water testing.

“Irish Water, the HSE, EPA and Fingal County Council will continue to liaise on the Leixlip Water Treatment Plant, the protection of public health being the number one priority.”

Minister Eoghan Murphy visited the Leixlip plant last week to survey ongoing works to upgrade the plant.

Local Sinn Féin Councillor Mark Ward however questioned the capacity of the Irish Water plant in Leixlip to serve the increase in use.

“Previously my constituency of Clondalkin and Lucan was served by the Ballymore Eustace water plant in Celbridge, this was changed to Leixlip with no consultation with the general public,” he said.

“The two recent boil water notices make me question the capacity of the Leixlip plant to supply all the additional homes since this change was made.

“It also raises questions of governance by Irish Water particularly in the delay in notifying the public during the first scare.

“Irish Water also reported that the reason for the most recent boil water notice was due to heavy rainfall.

“We live in Ireland; heavy rain is a regular occurrence.

“This does not fill me with confidence that this will not happen again.”

“I received reports that the Leixlip plant is due a substantial upgrade next year. I argue that this upgrade should have taken place prior to supply being changed from Celbridge.

“I have also asked that the supply be changed back to Celbridge and that if there are any changes in the future that a full public consultation is carried out”