The dataset of ZOCs was primarily generated in relation to the national groundwater quality monitoring programme. It was done for each of the approximately 200 monitoring points in that programme at the time. In addition, ZOCs were produced for drinking water sources (supplied by a groundwater or spring source) above a certain size and those at the time on the Remedial Action List (RAL). So, in total, there are approximately 350 sites that have been completed. The accompanying pdf outputs (mainly maps plus a few data figures) are on the EPA website, along with the shapefile. The work ran in parallel with a source protection zone (SPZ) delineation project (a more intensive piece of work with more robust outputs), which were done for a subset of the above ZOCs; approximately 45. The Geological Survey Ireland (GSI) host the national repository for SPZs and the reports and GIS are available on their website (alongside the ones they have created). These are not shown on the EPA website.