Revised and updated, this second edition includes new coverage of aquifers, US federal regulations, groundwater quality, and history of hydrogeology, and offers new international case studies. Useful as a field guide and a textbook, it contains standard methods for planning and undertaking hydrogeologic investigations, presenting ASTM standards and EPA and US Geological Survey field techniques, and covering hydrogeologic fundamentals, conceptual models, planning, surface and subsurface investigations, field inventory, stream flow and water quality measurements, and report preparation.