Significant issues at a Donegal water supply are making it “vulnerable to failure” and poses a health risk to the public, the EPA has warned.
The Glenties-Ardara supply was the only supply in Donegal on the Remedial Action List at the end of 2019. Supplies are added to the list if EPA is concerned about it not having a treatment barrier or a treatment barrier is not performing adequately.
Concern surrounds the Glenties-Ardara site due to it not having any completion date for planned repairs.
The supply has been found to have inadequate treatment for Cryptosporidium and elevated levels of Trihalomethanes above the standard in the Drinking Water Regulations.
Cryptosporidium is a parasite found in human or animal waste and, if they are present in drinking water, can cause diarrhoea. If the parasite is present in a supply, then appropriate treatment processes (referred to as a ‘barrier’) must be put in place.
Trihalomethanes form when natural organic matter in the water source, such as rotting vegetation, reacts with chlorine used in the disinfection treatment process.
Irish Water has said that the action programme to address issues at Glenties-Ardara will depend on the outcome of the installation of a second aerator.
The EPA Drinking Water Quality in Public Supplies Report 2019, released today, shows that the quality of drinking water in public supplies remains high with 99.9% compliance with bacterial limits and 99.6% compliance with chemical limits. The continued high levels of water quality being achieved are positive for consumers.
“However, increasing uncertainty in Irish Water’s planning and delivery of critical improvements to water treatment plants is making supplies vulnerable to failure, posing a risk to the health of a large portion of the population,” said the EPA.
The EPA’s Remedial Action List contained 52 supplies nationwide with significant issues to be addressed by Irish Water at the end of 2019. While this figure is down from 63 supplies in 2018, the population affected by these supplies has doubled in the same period to over 1.1 million.
Donegal showed some of the best improvements regarding trihalomethanes (THM) standards last year. Donegal had two supplies affected by THM failures in 2019 – down from 14 in 2017.