Groundwater is an important and abundant natural resource in Ireland. Groundwater quality is generally good, but contamination problems exist. There is increasing public concern about water quality, and national and EU legislation require measures to protect groundwater.

Since 1991, the Geological Survey of Ireland (GSI) has produced groundwater protection schemes (GWPSs) for about half the country. Each GWPS comprises map suite aimed specifically at local authority needs.

GWPSs developed through consultation with relevant professionals in the 1990s, based on three basic ideas: 1) Geoscience information needs an appropriate place in the spatial planning process. 2) Geoscience information must be available to decision-makers in a relevant and comprehensible format and appropriate scale. 3) GSI, the national geoscience agency, was best placed to fulfil this role.

The GWPS concept won the approval of the relevant Government department (Dept of the Environment and Local Government) and the Environmental Protection Agency (EPA), and an explanatory document was jointly published by the three bodies in 1999.

A GWPS comprises: (a) Land surface zoning (b) Groundwater Protection Responses for potentially polluting activities

Land surface zoning delineates: (i) Aquifers (ii) Source protection areas for selected groundwater sources (iii) Groundwater Vulnerability to contamination

From maps of Bedrock Geology, Subsoil (Quaternary) Geology, Outcrop/Depth to Bedrock, and Hydrogeological Data we derive maps of Aquifers (Regionally Important, Locally Important, and Poor) and Groundwater Vulnerability (Extreme, High, Moderate and Low, depending mainly on subsoil thickness and permeability). These are combined to show Groundwater Protection Zones. The map suite is also in demand for other purposes, particularly route planning for major new roads and pipelines.

Groundwater Protection Responses, describing the likely acceptability, conditions and needs for further investigation, are published for landfills, septic tank systems and landspreading of agricultural wastes. Others are planned.

In GIS format, a GWPS can be accessed by public authority staff on desktop terminals, and by the general public via a web site or front-office terminal. GWPS data should be available on the GSI web site (http://www.gsi.ie) in the near future.