This technical report contains detailed data which are underlying the information evaluated and presented in the EEA Environmental Assessment Report ie Groundwater Quality and Quantity in Europe, European Environment Agency (1999). Data were mainly received from questionnaires distributed to 44 European countries through the EEA´s Environmental Information and Observation Network (EIONET) including the 18 EEA member countries, 13 Phare countries, 7 Tacis countries and 6 other European countries. Responses were received from 37 countries. Questionnaire content: Monitoring data on:Pesticide , Nitrate, chloride, pH-value, alkalinity and electrical conductivity. Other relevant sources of pollution; Quantity data on inland water/groundwater; Areas with groundwater over-exploitation; Wetlands endangered from groundwater over-exploitation; Most important human interventions affecting groundwater; National strategies to improve groundwater quality and quantity; General data on pesticide usage/sales.