Dáil Éireann Debate, Tuesday - 20 February 2018
588. Deputy Thomas Byrne asked the Minister for Housing, Planning and Local Government the status of the national roll-out of testing of alarm systems to ensure the non-occurrence of elevated chlorine levels in the public water supply. [8114/18]
Amharc ar fhreagra589. Deputy Thomas Byrne asked the Minister for Housing, Planning and Local Government if his attention has been drawn to the recent malfunction of an elevated chlorine alarm system in an area (details supplied) in County Meath which resulted in a water ban for over 500 homes. [8115/18]
Amharc ar fhreagra590. Deputy Thomas Byrne asked the Minister for Housing, Planning and Local Government the number of water plants that have been fitted and not fitted respectively with testing of alarm systems for elevated chlorine levels. [8116/18]
Amharc ar fhreagraI propose to take Questions Nos. 588 to 590, inclusive, together.
Since 1 January 2014, Irish Water has statutory responsibility for all aspects of water services planning, delivery and operation at national, regional and local levels.
While monitoring chlorine levels is an operational matter for the utility, my Department was advised of the recent chlorine-related incident in Co. Meath which resulted in a water use ban affecting some 1,200 persons being imposed on 7 February 2018. I understand that following the successful resolution of the matter, normal water service was restored to the homes concerned on 8 February 2018.
Chlorine is the most commonly used disinfectant in water treatment in Ireland. It is added at the water treatment plant and for larger networks may require boosting at key locations including reservoirs and pumping stations to ensure the correct levels of chlorine are maintained throughout the entire network.
I understand that Irish Water is currently undertaking a national programme of works to improve the quality of drinking water and increase water quality compliance levels across the country. As part of this programme over €40 million is to be invested in the upgrade and standardisation of disinfection systems currently installed in over 830 public drinking water treatment plants.
I am advised by Irish Water that the Disinfection Programme is being carried out in two phases. Phase 1 involves the assessment of the condition and performance of the existing disinfection systems at water treatment plants across the country. This will determine the works required to ensure that the treatment plant disinfection process meets the specified requirements. Phase 2 then involves carrying out any necessary upgrade works. Such works may include upgrade of chemical storage and treatment processing infrastructure, upgrade of ultraviolet (UV) disinfection systems, upgrade of monitoring systems and generation of Critical Process Alarms.
Irish Water is currently identifying and planning the appropriate mitigation measures to be carried out at water treatment plants throughout the country to achieve water quality compliance. To date, Irish Water has assessed over 450 sites and commenced upgrades to over 130 water treatment plants.
Chlorine levels in drinking water are monitored primarily via a rigorous sampling programme which tests the levels of chlorine in the water at various points from the treatment plant to the customer’s tap. Any changes to chlorine levels are fully investigated and any necessary actions agreed. This monitoring programme is supplemented by alarms which can alert to issues often associated with the point at which chlorine is added. To ensure a fully robust system all points of chlorine addition will be considered over time including the boosting points along a network. Irish Water has begun this process, which will take some time to complete given the vast amount of assets to be audited and adjusted when reservoirs, pumping stations and boosting points within a network are included.
