Ms AnnMarie Farrelly:

I thank the committee for allowing me to address it. I am joined today by John Daly, director of services. Leixlip water treatment plant was initially constructed in 1967 and has been upgraded and expanded six times, most recently in 2014 when the capacity of the plant was extended from 168 million l to 207 million l per day. The treatment plant is a conventional plant for the treatment of river water, which involves coagulation, settlement, filtration, chlorination and fluoridation. It is made up of two sections which we refer to as the old and the new and the incident on 21 October occurred in the older installation.

Fingal County Council currently operates Leixlip water treatment under a service level agreement with Irish Water. Prior to the recent incidents, there has been no general boil water notice due to a failure of the Leixlip water treatment plant. Fingal County Council staff supported Irish Water and the EPA during the period of the first boil water notice, which assisted in the notice being lifted as early as possible. We are working with Irish Water to do likewise in respect of the current incident. The EPA audit report of 28 October describes the causes of the incident which occurred on 21 October.

From our analysis, the accumulation of debris commenced at approximately 3 p.m. Early indications of deterioration in water quality were identifiable between 5 p.m. and 5.30 p.m. By 6.15 p.m., the water quality was outside the normal operating limits for acceptable water quality and reached a critical level by 7.50 p.m. When the incident was identified at 9 p.m., prompt action was taken and the repair was effected by 11.30 p.m. Shut down of the system occurred at approximately 10.15 p.m. The EPA requirement for an automatic shutdown of the plant or individual elements of the plant or both was in place in the new section of the facility before the incident and was planned for the old section. Automatic shutdown has now been implemented throughout both treatment plants. This is a significant intervention, which will assist greatly in preventing any such future incidents. I am referring to the incident on 21 October.

In addition to the automation, Fingal County Council is in the process of further strengthening, monitoring and control at the plant since the incident, pending implementation of Irish Water's national control centre as follows: the supervised control and data acquisition, SCADA, computerised control system is being upgraded this week to require regular activation of operational controls by the duty operator to demonstrate response to all alarms; the critical alarms system will be upgraded to provide for automatic alerts in order that the on-call duty manager is notified quickly; the introduction of additional systematic monitoring and review of the SCADA system over the 24-hour period is being implemented and enhanced arrangements for plant supervision by the on-call duty manager are being implemented to support operations over the 24-hour period. In addition, critical incidents will be notified to Irish Water immediately and in this regard, the out-of-hours protocol with Irish Water has been reviewed, which will enhance the communications of incidents. The additional requirement to investigate the lining of the alum tank, which was the initial cause of the incident on 21 October, will be carried out by Fingal County Council as soon as possible and within a six-week period. This will require the tanks to be drawn down in sequence and examined. Following assessment, any capital investment will be identified to Irish Water for action. The matter of the failure to respond to alarms is the subject of an ongoing internal investigation.

It should be noted, however, that Fingal County Council views the optimal solution as being the implementation of the Irish Water's national control centre and we welcome the EPA recommendation that Leixlip be connected to the centre without delay. The completion of the new plant facilitated the implementation of a range of refurbishments and improvements to the older plant, which could not be progressed until the new plant was commissioned.

The following works were identified: upgrade of controls and a new SCADA system, which is now complete; rehabilitation of the filter channel, which is now complete; repairs and replacement of electrical equipment, which has commenced and is ongoing and automated chlorine dosing, which is now complete. Other works identified were automated back wash sequencing, which is now in place; PH correction, which currently is in design phase; replacement of valves and deep pipework, which is complete; and rehabilitation of sand filters, of which four out of 15 such filters have been refurbished. Progress on these items is jointly monitored by Irish Water and Fingal County Council staff. We note the recommendation by the EPA for a system-wide risk assessment of the plant. Fingal County Council will assist Irish Water in a rapid review and the identification and implementation of any necessary works. Fingal County Council acknowledges the disruption due to the issue of a boil water notice and offers apologies to all those affected by the issuing of the boil water notice on 22 October and the second notice, which is currently in place. We remain committed to performing our duties under the service level agreement with Irish Water to ensure a continued safe water supply.