Dr. Tom Ryan:

I thank the committee for inviting the EPA to assist, as appropriate, on the issues affecting the quality of water in Ireland, boil water notices nationally, and the recent boil water notice for parts of counties Dublin, Kildare and Meath, noting that there is now another evolving situation at the plant in question.

I am joined by my colleagues from the EPA's office of environmental enforcement, Dr. Michelle Minihan and Mr. Andy Fanning, who is a programme manager in the area.

The EPA is the drinking water quality regulator for public water supplies and works to ensure that drinking water supplied by Irish Water meets the standards of the drinking water regulations so that public water supplies are safe to drink. Local authorities are the regulators with responsibility for the drinking water quality of private water supplies, if I may make that distinction.

As the utility supplying public water, Irish Water is responsible for ensuring that public water supplies meet the standards of the drinking water regulations. Other suppliers including group water schemes and private suppliers are similarly responsible for the drinking water they provide.

The EPA's primary focus is to oversee Irish Water's response to drinking water quality failures. However the agency also requires Irish Water to take actions to prevent drinking water quality failures from happening in the first place and is working to ensure that investment is prioritised for those water supplies that pose the greatest risk to public health.

Irish Water must notify the EPA of any drinking water quality failures and the agency then oversees Irish Water’s investigation and their actions in response to the failure. As part of the agency's role in drinking water quality investigations, it may audit drinking water supplies and treatment processes, issue legal directions, take legal prosecutions in certain circumstances, or place a water supply on its remedial action list. The remedial action list was first prepared by the agency in January 2008 and is a dynamic list of public water supplies that the agency has identified as at risk and as priorities for remedial action by Irish Water.

I will briefly address some of the issues affecting the quality of drinking water in Ireland. In its most recent report on the quality of public drinking water supplied by Irish Water published in September this year, the EPA found that the overall quality of drinking water remains high, with 99.9% compliance with microbiological standards and 99.6% compliance with chemical parameters in 2018. While this indicates that the majority of public water supplies are safe, further measures are necessary to improve the security of our supplies and avoid long-term boil water notices into the future. The 2018 report set out a series of issues affecting the quality of the drinking water supplied by Irish Water that require action, namely, ensuring adequate disinfection of treated water, reducing the presence of trihalomethanes, THMs, in treated water, replacing of lead water mains and household pipes, eradicating persistent pesticide failures above the limit set out in the drinking water regulations, and establishing drinking water safety plans for supplies. These issues have been recognised for a number of years and the EPA has recommended that Irish Water take a strategic national approach to them to prevent further drinking water quality failures. The report also highlighted that cryptosporidium detections have increased in the past three years. It was detected in 25 public water supplies in 2018, up from 17 in 2017 and 12 in 2016.

Cryptosporidium is a parasite found in human or animal waste and, if present in drinking water, can cause persistent diarrhoea. Illness is often more severe in small children and elderly people and can be very serious in people who are immunocompromised. If cryptosporidium might be present in a supply, appropriate treatment processes, referred to as a "barrier", must be put in place. These barriers also serve to address certain other parasites, including giardia, which can give rise to similar illnesses, if consumed.

Adequate treatment is required at all water supplies where cryptosporidium has been identified as a risk. It is not enough to have a barrier in place; it must also be properly operated and maintained. At the end of 2018, the EPA’s remedial action list, RAL, included 15 supplies with inadequate treatment for cryptosporidium. The EPA will continue to monitor Irish Water’s progress towards ensuring that all supplies have an adequate barrier to cryptosporidium.

The issuing of a boil water notice is not a statutory function of the EPA but is done by Irish Water or a private water supplier in consultation and agreement with the HSE. As the environmental regulator of Irish Water, the EPA emphasises that there is a need for boil water notices and other water restrictions, in certain circumstances, to protect human health. During 2018, 44 boil water notices were in place in 14 counties, affecting more than 97,000 people. This is an increase compared to 2017, during which 42 boil notices were in place, affecting more than 21,000 people. The main reason for the increase in the number of people affected is that 65,000 people were on a boil water notice for three days in early 2018 when a disinfection failure occurred at the Vartry reservoir supply. More than 13,500 people were also affected by 12 precautionary boil water notices issued due to Storm Emma in March 2018.

It should be noted that a long-term boil water notice is one that is in place on a supply for longer than 30 days. Of the 44 boil water notices in place during 2018, 26 were short-term notices and were lifted within one month. Five were long-term notices that were in place for longer than one year.

I want to turn now to the recent boil water notice affecting parts of counties Dublin, Kildare and Meath. In addressing this, I acknowledge this is an evolving situation and, if the Chairman allows, I will say a few further words on the current issues at the conclusion of my statement.

Irish Water informed the EPA at 11 a.m. on Tuesday, 22 October of a mechanical failure at Leixlip water treatment plant, which had occurred on Monday, 21 October. The EPA participated in a meeting between HSE and Irish Water on the afternoon of Tuesday, 22 October to assess the risk this incident posed to consumers. Irish Water and Fingal County Council, following consultation and agreement with the HSE, issued a boil water notice. The boil water notice was a preventative measure and was necessary to ensure that public health was protected and consumers were not at risk from cryptosporidium or giardia, the microscopic parasites that can cause illness.

On Thursday, 24 October, EPA inspectors conducted an audit at Leixlip water treatment plant. The purpose of the audit was to establish the full facts of the incident and the corrective actions taken. It was also to verify the performance of Leixlip water treatment plant and to assist in gathering the information to facilitate the lifting of the boil water notice. EPA inspectors also reviewed the recommendations of the agency's previous audit of 22 March 2019 and assessed the implementation of the actions taken to address those recommendations.

In the audit, the EPA inspectors found the incident began at 3 p.m. on Monday, 21 October, and ended at 5 a.m. on Tuesday, 22 October, when remedial works restored the affected production line. The water treatment plant appears to have operated satisfactorily between 5 a.m. on Tuesday, 22 October and the current issue emerging. There was sampling of treated water for cryptosporidium and giardia in the critical period before, during and after this incident. These samples indicated that the quality of water supplied following restoration of the production line was satisfactory. A blockage in the coagulant dosing line resulted in operational difficulties with the water treatment processes and gave rise to elevated turbidity levels in treated water. The elevated turbidity levels in treated water indicated a significant risk to the safety of the water supply because the treatment barrier for the removal of cryptosporidium and giardia was compromised and there was a risk of breakthrough of microscopic parasites into the water supply. There was a failure to respond to multiple alarms that activated in response to the elevated turbidity. Irish Water and Fingal County Council implemented automatic plant shutdown for the whole plant when turbidity alarms were not responded to within 15 minutes on 24 October 2019, the day of the audit.

While the Leixlip water treatment plant was resorted to a satisfactorily operating status following the incident, the level of treatment at this plant is not sufficient to manage the risk posed by the River Liffey source water, as further evidenced by the emerging situation. In particular, there is a deficit for treatment of parasites such as cryptosporidium and giardia. Filter upgrade works are under way to reduce this deficit but will not be sufficient to confirm adequate treatment. In its October audit report, the EPA recommended that ultraviolet disinfection be considered by Irish Water as an additional treatment barrier to inactivate cryptosporidium and giardia at the Leixlip water treatment plant. As an ultimate failsafe, ultraviolet disinfection will inactivate any cryptosporidium and giardia parasite in the water supply to ensure the protection of public health.

The boil water notice in question was lifted by Irish Water at 4.30 p.m. following meetings on the afternoon of Friday, 25 October, between the HSE and Irish Water and between the HSE, Irish Water and the EPA. During an audit of the Leixlip water treatment plant in March 2019, the EPA highlighted the risk of this type of incident occurring, following a mechanical failure of a chemical dosing pump at the plant, and recommended that plant operators respond immediately to any alarm generated, and that if an operator failed to respond to an alarm, that Irish Water should ensure the plant automatically shuts down to prevent inadequately treated water being supplied to consumers. In May, in response to that audit, Irish Water confirmed the plant would automatically shut down when an operator failed to respond to an alarm. The EPA audit on 24 October found the automatic plant shutdown arrangement was implemented on one production line at the Leixlip water treatment plant in April 2019 and was only implemented on the remaining two production lines at the plant on the day of the audit. The EPA's report following the audit on Thursday, 24 October, was published on 30 October on the EPA's website.

As committee members are aware, there is an emerging issue at the water treatment plant in Leixlip and I will take this opportunity to advise the committee on the EPA's engagement on the issue at this point. Yesterday morning, 4 October, Irish Water advised the EPA there were operational issues at the plant over the weekend. On Sunday, 3 November, two out of three of the production lines at the Leixlip plant were shut down from 1 p.m. due to high turbidity levels in the raw water entering the plant, attributed to the very high rainfall experienced on Saturday, 2 November.

This shutdown had depleted the reserves of treated water in the reservoirs and distribution network served by Leixlip. Due to ongoing heavy rainfall yesterday, there continue to be issues with the quality of raw water entering the plant. The increase in turbidity in the filtered water gives rise to a risk of breakthrough of the parasites cryptosporidium and giardia into the water entering the distribution system.

A meeting was held yesterday afternoon between Irish Water, Fingal County Council, the HSE and the EPA. Following the meeting, Irish Water, in consultation with the HSE and having assessed the risk to public health, decided that a precautionary boil water notice was needed. The Leixlip plant returned to water production from all of its production lines yesterday evening to ensure the continuity of the water supply. Of course, it is vital that the supply be returned to safe production as soon as possible. The EPA will play its role in verifying that the plant is operating safely, which will include an audit of the plant. The appropriate time to audit will be when Irish Water and Fingal County Council are satisfied that the plant has returned to satisfactory performance. The EPA's role will be to verify that performance before the boil water notice can be lifted.

I assure the committee that the agency will continue to provide regulatory oversight. We are happy to answer whatever questions arise from our statement.