Removal follows upgrade of treatment plant by Irish Water

There was good news for Mayo in the recently published Environmental Protection Agency’s (EPA) Remedial Action List (RAL) where it was confirmed that the Ballina-Lisglennon public water supply scheme has been removed from list. The scheme was on the RAL for elevated levels of THMs. Irish Water upgraded the water treatment plant to enable its removal from the EPA’s to-do list with works including optimisation of the processes at the plant along with an upgrade of the disinfection system.

Only one Mayo scheme remains on the RAL for elevated levels of THMs and that’s the Inishturk public water supply.

Irish Water has put in place the first national THM plan and a prioritised programme of investment to address all inadequacies in drinking water parameters including THMs. By 2021 the utility plans to reduce the number of schemes on the RAL to zero with an investment of €327 million in upgrading water supplies at risk from THMs.

THMs, or Trihalomethanes, are chemicals formed by the reaction of naturally occurring dissolved organic material and chlorine which is used for disinfection in order to protect against pathogenic bacteria.

There are two other water supplies in Mayo on the RAL - Kiltimagh and Lough Mask Water Treatment Plants and specific improvements to both processes are underway. At Kiltimagh water treatment works, the disinfection system is being upgraded and the water treatment process optimised. At Lough Mask water treatment works a €1.6m project to improve the treatment process is underway with an expected completion date within the coming months. 

Speaking about the RAL and the ongoing work in Mayo, Irish Water’s Regional Compliance Specialist, Pat O’Sullivan, said “The publication of the latest RAL update is a confirmation of the focus and dedication of Irish Water and Mayo County Council in ensuring the delivery of clean and wholesome water in the county.

As a single utility Irish Water is able to conduct a comprehensive evaluation of the performance of Ireland’s drinking water production plants and where serious compliance challenges are found they can be tackled more effectively and efficiently. The decommissioning of smaller water treatment plants and rationalisation of water supply zones as has happened in Mayo could only be achieved by a single utility.” 

The RAL is updated quarterly by the EPA for those water supplies where investment in treatment processes is required. Irish Water has a prioritised programme of investment for all schemes on the RAL.

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