The application of fluid mechanics theories to treat environmental problems is becoming increasingly important in the field of environmental engineering. To provide environmental engineers with a comprehensive survey of recent developments, the Fluids Committee of the ASCE Engineering Mechanics Division has culled from the entire field of fluid mechanics the information most relevant to environmental engineers. The first chapters cover principles of fluid mechanics, followed by contemporary applications to environmental problems involving river, lake, coastal, and ground water areas. In addition to providing valuable information to practitioners, this book also serves as a text for either an advanced undergraduate or introductory graduate level course. The chapters include: Turbulent Diffusion; Mixing of a Turbulent Jet in Crossflow - The Advected Line Puff; Multi-Phase Plumes in Uniform, Stratified, and Flowing Environments; Turbulent Transport Processes Across Natural Streams; Three-Dimensional Hydrodynamic and Salinity Transport Modeling in Estuaries; Fluid Flows and Reactive Chemical Transport in Variably Saturated Subsurface Media; Heat and Mass Transport in Porous Media; Parameter Identification of Environmental Systems; Finite Element Analysis of Stratified Lake Hydrodynamics; Water Quality Modeling in Reservoirs; and Linear Systems Approach to River Water Quality Analysis.