Two serious incidents at water treatment plants put 885,000 people at risk

Irish Water criticised in report over failures in the water supply system

Two serious incidents during 2021 at Gorey and Ballymore Eustace water treatment plants put the health of approximately 885,000 people at risk, “highlighting significant failings in oversight and management by Irish Water”, according to the Environmental Protection Agency (EPA).

The criticism of the utility is in the EPA’s Drinking Water Quality in Public Supplies Report for 2021 released on Friday, which shows overall quality in supplies remains high, with over 99.7 per cent compliance with bacterial and chemical limits.

Irish Water, however, is also criticised over a number of other failures in the supply system.

The number of supplies breaching trihalomethanes (THM) standards increased in 2021, “reversing all progress seen in recent years”, it warns. They are a byproduct of chlorine disinfection and are formed where there is an excess of organic matter in the water source — long-term exposure poses a health risk.


“Progress to remove lead from drinking water networks is too slow, with the need for stronger leadership at national level,” the report adds.

The continued high levels of water quality being achieved “are positive for consumers and indicate that water is safe to drink”, it underlines.

The number of people served by “at-risk” supplies on the EPA’s remedial action list (RAL) has reduced, arising from upgrade works at two large water supplies; Leixlip water treatment plant which supplies more than 590,000 people in Cos Kildare and Dublin, and Vartry treatment plant which supplies 127,000 people in north Wicklow and south Dublin.

The Gorey and Ballymore Eustace incidents “highlighted significant failings in oversight and management by Irish Water and local authorities”, it adds, noting community illness and hospitalisations occurred due to problems at the Gorey plant.

The EPA instructed Irish Water to implement a number of actions at all supplies, to prevent the reoccurrence of similar issues. “As a result of these actions, more drinking water quality issues were detected and reported, with the number of boil water notices increasing significantly in the last quarter of 2021,” the EPA report confirms ‑ 211,000 people were affected by boil water notices in 2021.

“The serious incidents at Gorey and Ballymore Eustace water treatment plants last year, which resulted in unsafe water being released for consumption, have highlighted Irish Water’s fundamental obligation to ensure our public water supplies are properly operated, and managed, to protect public health,” said EPA director Dr Tom Ryan.

“Increased vigilance is needed by Irish Water and local authorities in their oversight and management of plant operations to ensure incidents are dealt with appropriately and in a timely manner,” he added.

‘Significant improvements’

Boil water notices were affecting an increasing number of consumers, Dr Ryan noted. While the EPA recognised the challenges such notices posed for individuals and communities, they were necessary to protect public health. “High incidences of boil water notices will remain with us until Irish Water improves the resilience of drinking water plants.”

The RAL list of “at-risk” supplies identifies where long-term improvements are needed in drinking water infrastructure to protect public health.

At the end of 2021, there were 52 “at-risk” supplies serving some 375,000 people — down from more than 1 million consumers in 2020. However, the latest RAL (as of September 2022) has seen some of this progress eroded, with the population served by “at-risk” supplies increasing to about 575,000.

In addition, the length of time it takes to implement improvements at supplies “is not acceptable as it means these supplies remain vulnerable for longer”, the report notes. The EPA requires Irish Water target investment and resources to both reduce the number of supplies on the RAL and time it takes to implement improvements.

“It is welcome to see how targeted enforcement has led to significant improvements at large supplies such as Leixlip and Vartry, supporting the security of these critical water supplies into the future,” said EPA programme manager Noel Byrne.

For supplies to be secure into the future, Irish Water must resolve the “at-risk” supplies on the RAL and ensure future actions were targeted where they are most needed to protect public health, he added. “In particular, the deterioration in compliance with THM standards needs to be addressed as a matter of priority”.

Lead in drinking water causes a cumulative risk to human health. The EPA report highlights “the slow rate of lead replacement by Irish Water, as it will take almost a quarter of a century to address the risks posed to public health from lead in drinking water at the replacement rate observed in 2021″.

“Leadership is required at a national level by relevant Departments to address this issue. A report from these Departments on assessments of lead pipework in public buildings and plans to remove lead from these buildings is overdue,” it says.

The report including updated RAL list — and proposed remedial measures and associated timeframes — is available at

Irish Water welcomed confirmation of further improvement in drinking water quality compared to 2020 which, it said, showed the benefits resulting from its “ongoing high level of investment in water services”.

“In 2021, we invested over €460 million in Ireland’s water treatment plants and networks, with 12 water treatment plants built or upgraded and an additional 39 sites upgraded under the national disinfection programme,” it added. As a result of this, the population on the EPA’s list of “at risk” supplies reached its lowest ever level in 2021.

The report recognised ongoing improvements made by Irish Water in testing and monitoring drinking water supplies have played a key role in identifying risks to drinking water quality and protecting public health, it said.

“Many of these risks existed for years but only came to light due to the more robust testing and sampling regimes that we have put in place. In some cases this has resulted in protective boil water notices or other restrictions being introduced while the issues are addressed,” it confirmed.

Significant progress has also been made in developing systems to improve the management of incidents, it said. In response to the incidents in Gorey and Ballymore Eustace, “the new National Operations Management Centre has been stood up on a 24/7 basis and so far 56 of Ireland’s largest drinking water plants, catering for a population of 2.85 million people, have been connected”.

This enables these plants to be monitored around the clock and action to be taken immediately when issues arise. Training has also been rolled out to all water services staff across the country to better equip them to manage or escalate incidents, “so that we can protect and inform our customers”, it added.

“We have increased investment in our drinking water services year on year, and this is reaping big benefits for all our customers nationwide, giving them the assurance that, when they turn out their tap, they can enjoy clean, safe drinking water,” said Margaret Attridge of Irish Water.

“We recognise of course that challenges remain in some areas and we have prioritised our efforts in addressing these. In particular our enhanced focus on monitoring and testing supplies allows us to identify problems early and take action to fix them and, where appropriate, notify the public of any risks to their drinking water,” she said.

“It will take a number of years and high levels of investment to bring our public water supply to the standard we all strive for but we are confident that we are on track to achieve this. Public health is our top priority and we will continue to work in partnership with our stakeholders, including the EPA, to ensure world class drinking water supplies for all our customers.”

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times