This eight-chapter book addresses all important aspects associated with the problem of excessive nitrate concentrations in ground water resources. Chapter 1 provides fundamental information on the nitrogen cycle and health concerns from excessive concentrations. Subsurface processes such as nitrogen transformations, transport and fate, and leaching are highlighted in Chapter 2. Case studies related to nitrate introductions from agricultural uses of fertilizers and land disposal of domestic wastewaters are described in Chapter 3, while Chapter 4 focuses on the use of vulnerability mapping based on hydrogeological features as a tool for pollution prevention or management. The development of a nitrate pollution index is included in Chapter 5, and descriptions of source characterization models, nitrate transport models, along with several others, are in Chapter 6. Finally, Chapter 7 highlights management measures for reducing nitrate pollution potential, while Chapter 8 features a discussion of treatment measures for excessive nitrate concentrations. This book is used by both researchers and regulatory agencies charged with responsibilities for ground water management and pollution control.