This book follows a systematic approach to completing a hydrogeological study and explains how to decide on the measurements that are needed and on the instruments and techniques required. Measurements of groundwater levels, rainfall and evaporation spring and stream flows and the use of ground water tracer techniques are covered. There is a great deal of practical information on all aspects of planning and completion of field investigation and on the interpretation of field evidence. Advice on safety is also included. This third edition has been fully revised and updated to bring the book into line with developments in environmental regulations. The order of the chapters reflects the structure of a hydrogeological project and the development of a conceptual model up to completion of a report. The focus is on current practical applications of hydrogeological investigations using new case histories and new chapter on specialist techniques has been included. This book is suitable for undergraduate and postgraduate students of geology, hydrogeology, environmental sciences and engineering, as well as a wide range of professionals working in the water resources and environmental protection fields.