This book presents current standard methods and guides for planning and undertaking ˜eld investigations. It covers concepts, aquifer identi˜cation, groundwater movement, recharge, discharge, and rules for professional conduct. Information is presented on hydrogeologic principles, conceptual models, sources of hydrologic information, geophysical methods, surface investigations, subsurface investigations, well inventory, design of aquifer tests, stream £ow measurements, report planning, report writing, and report review.