18 May 2017 Go back to News
THM risk in Portumna water supply removed in latest EPA RAL update
Work continuing in Galway to secure high quality water supplies for over 11,000 people still on the RAL
The THM risk which led to the Portumna water supply being added to the Environmental Protection Agency’s (EPA) Remedial Action List (RAL) has been removed according to the latest RAL which was published last week. And while the Portumna supply is now THM-compliant, Irish Water is continuing to enhance process optimisation procedures at the treatment plant. While these works are taking place, the Portumna supply will remain on the RAL under the new heading ‘treatment and management issues’.
This time last year there were 13 Galway water supplies on the RAL, but due to significant investment by Irish Water this has been reduced to four with ongoing works taking place at these plants to ensure their removal from the EPA’s action list.
This work comes in the aftermath of seven boil water notices being lifted on water supplies in Co Galway last year which benefited 22,834 people who no longer have to boil their water before consumption, making Galway a boil water notice-free zone.
The remaining schemes on the RAL are Ballinasloe Regional Water Supply Scheme, Inishmean, Portumna Public Supply, and Williamstown Public Supply. Bar Portumna, the other three supplies are on the RAL due to elevated levels of THMs in the water.
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.
The Inishmean supply, which serves a population of 161 people was added to the last RAL for elevated levels of THMs in the water. Irish Water has identified the solution and is working to have these works completed before the end of the year. The utility is carrying out upgrade works to the Ballinasloe Water Treatment Plant which supplies a population of 7,959 people and the utility is also carrying out works in Portumna to benefit 2,010 local consumers.
The remaining Galway scheme is Williamstown which supplies 986 people. This scheme was on a boil water notice which was lifted last year after significant improvements to the treatment process and the installation of a UV system was implemented by Irish Water. The longer term plan is to connect this scheme to the Lough Mask Regional Water Supply and works are progressing on this with an estimated completion date of December 2017.
Welcoming this latest RAL update 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 Galway County Council in ensuring the delivery of clean and wholesome water in the county. Works are advancing on the four remaining schemes which we are confident of delivering by year end.”
In November 2015, Irish Water announced an investment of €36 million in water infrastructure and €58 million in wastewater infrastructure across Galway. 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.