Portlaoise Public Water Supply (PWS) (Drinking Water Code 1600PUB1004) was placed on the Remedial Action List (RAL) in 2014 due to ‘inadequate treatment for Cryptosporidium’. Nine production wells currently abstract 9,900 m3/d from a Regionally Important Karst Aquifer and a Locally Important Aquifer that is Moderately Productive only in Local Zones.
The report forms an evidence based assessment of cryptosporidium and water quality generally in the well field. It is based on collection of data from Irish Water (12 months hydro chemical and water quality data), Laois County Council data and records, existing site investigation and hydrogeological reports, Geological Survey Ireland Karst tracing, archives and website, well head inspections, real time monitoring of well levels and their operation, desk studies of relevant maps and reports, site visits and field mapping and supplementary water sampling of monitoring wells by Jacobs and TOBIN.
The Water Safety Plan approach provides a framework within which the risk can be assessed and it includes using Risk Screening Methodology for Cryptosporidium as a starting point on which to build the investigations and the risk assessment. Based on the evidence for the Risk Assessment, Portlaoise PWS is no longer on the EPA RAL site.