This book is concerned with the theory and practice of ground-water hydrology, the science of water in subsurface environments. It is divided into two main parts; (1) basic concepts dealing with the origin, movement of ground water and its recovery from wells, and (2) a qualitative and quantitative assessment of the chemistry of natural and contaminated systems. The book is developed around a process-oriented theme that organizes hydrologic phenomena based on physical and mathematical principles. It emphasizes the application of knowledge to the solution of practical problems encompassing areas of site characterization, hydraulic testing, and ground-water contamination. One of the important ways to learn about ground-water problems is to experience them first hand. Thus, the book relies on case studies, and demonstrations of techniques through worked problems. In spite of the fact that most of the hydrogeological world is hidden from view, there are exciting things to see in the field. We have attempted to bring some of these to you through the colored photographs and illustrations that are included on the book official web site:http://www.wiley.com/college/schwartz