Dr. Michelle Minihan:

On the point raised about the chlorine contact time, our audit found - as the Deputy correctly stated – in regard to the scenarios in which the Ballymore Eustace plant operates, the disinfection level is meeting the WHO recommended value of 15 mg/l per minute, but is not meeting the site specific target that Irish Water set. The site specific target is put in place so that there is an abundance of safety to ensure adequate disinfection under all conditions, including water temperature, changes in pH etc. That is something Irish Water was not aware of until we raised it. The Deputy rightly pointed out that our audit report referred to the fact that the national disinfection programme had assessed and surveyed the Ballymore Eustace plant site in 2019 and had not identified this. That observation in our audit report points to and identifies a lack of management oversight by Irish Water in the operation of the plant.

Additionally, during the audit it became clear the staff on site were aware of the intermittent chlorine drops and were trying to manage the problem, but it had not been escalated or reported to Irish Water for it to support, assist and intervene, if necessary. On the operational monitoring, which is ongoing daily at a number of plants that serve the greater Dublin area, when we received the information following the audit, we found the daily samples were pointing to lower than normal chlorine levels in the treated water leaving the plant. Those reports do not appear to have been assessed by Irish Water or factored into its oversight of the plant.