The EU Water Framework Directive (2000/60/EC) (WFD) establishes a framework for the protection, improvement and management of surface water and groundwater. All Groundwater Waterbodies (GWB) are represented as polygons. They are validated by scientists in the Geological Survey of Ireland and the EPA Scientists as meeting the criteria for a WFD GWB.
https://data.gov.ie/dataset/water-framework-directive-groundwater-waterbodies?package_type=dataset