A comprehensive analysis derived from papers presented at the First International Conference on Ground Water Quality Research, sponsored by the National Center for Ground Water Research. Covers the sources, types, and quantities of contaminants in ground water, methods for ground water quality research, subsurface characterization in relation to ground water pollution, and transport and fate of subsurface contaminants. Focuses on the scientific and technological challenges and accomplishments in ground water quality research and assesses the state-of-the-art developments in this area on an international scale.