Groundwater resources are facing increasing pressure from consumptive uses (irrigation, water supply, industry) and contamination by diffuse loading (e.g. agriculture) and point sources (e.g. industry). This cause major threat and risks to our most valuable water resource and on ecosystems dependent on groundwater. New information is need on how to better protect groundwaters and groundwater dependent ecosystems (GDE) from intensive land-use and climate change. The impacts of land-use changes and climate changes are difficult to separate as they partly result in similar changes in the ecosystems affected. The effects are highly interwoven and complex. The EU groundwater directive (GWD) and the water framework directive (WFD) provide means to protect groundwater (GW) aquifers from pollution and deterioration. At present, the maximum limits for groundwater pollutant concentrations have been set for nitrate and various pesticides. Also, water of sufficient quality and quantity should be provided to ecosystems dependent on groundwater. The European aquifers differ by their geology, climate, and threats to aquifers. This must be considered when general guidelines for management of these systems are developed. The concept of the present proposal is to base the research on different relevant aquifer sites in various European countries to test scientific issues and find new results to important problems. Seven WP are foreseen: WP1 Case studies on impacts and threats to GWs and GDEs WP2 Groundwater dynamics, re-charge and water balance WP3 Leaching to groundwater aquifers from different land-uses WP4 Groundwater dependent ecosystems: groundwater-surface water interaction WP5 Modelling processes in groundwater systems WP6 Concepts, scenarios and risk assessment WP7 Co-ordination