Explains the hydraulic processes that underlie in situ reactive zone treatments, this work addresses the complexities and heterogeneities of natural aquifers that are encountered in various treatment settings and introduces the concepts of pore-scale, fine-scale, and stratigraphic-scale heterogeneities. "The book reflects a realistic and successful approach to remediation. It is well researched and detailed enough to provide practical knowledge for engineers, scientists, and regulators in the prediction of fluid movement in the subsurface as well as in the design of pilot to full-scale remediation systems." - Laura L. Sanders, Book Editor, in Ground Water, 2009