The lives of almost 900,000 people were put at risk because of two serious failures at Irish Water plants, according to the Environmental Protection Agency (EPA).
The utility has been strongly criticised in a new report from the agency over the incidents at Ballymore Eustace in Co Kildare and Gorey in Co Wexford last year.
There were "significant failings and oversight by management" according to the report, which says lives were put at risk because of contaminated water supplies.
The Drinking Water Quality in Public Supplies Report for 2021, released on Friday, 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.
It said that it will be 24 years before the lead pipes under Irish Water’s control are replaced, based on the current rate.
The use of lead as a plumbing material was common in buildings built before and during the 1970s. There are an estimated 180,000 lead pipe connections under Irish Water’s control, with 42,000 replaced between 2017 and 2021.
Based on current funding, Irish Water is aiming to replace half of its lead pipe connections by 2030.
The report said the continued high levels of water quality being achieved “are positive for consumers and indicate that water is safe to drink”.
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.
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.