This book addresses one of the most challenging problems that plagues the environmental field today-subsurface contamination. The past three decades have ushered in various methods for removal of organic and inorganic contaminants from the subsurface to varying degrees of effectiveness. Because of the site-to-site variability in the nature of contamination characteristics, the pattern of waste disposal and accidental releases, the site characteristics and thus contaminant behavior, and hydrologic conditions, predicting the effectiveness of one treatment method over another is a daunting task. Field demonstration of innovative technologies is a key step in their development, however, only after successful scale-up from laboratory testing. This book features chapters written by researchers who have linked laboratory- and field-scales in efforts to find creative, cost-effective methods for prediction of successful remediation of contaminated soil and ground water. State-of-the-art technologies using physicochemical removal methods and biological methods are discussed in the context of not only their effectiveness in remediating organic and inorganic wastes from various subsurface environments but also in terms of useful flask-scale methods for measuring and predicting their field-scale effectiveness. Chapters address sorption and hydrolysis of pesticides by organoclays, use of Fentons agents to destroy chlorinated solvents removed from the subsurface by granulated activated carbon, methanol flushing as a means of removing toxaphene from soils, natural attenuation as a method for effectiveness of remediation metals and biodegrading acid-mine drainage constituents, and biodegradation ofradiologically contaminated soils. Also addressed in this book are current and future methods of assessing microbiological activity potential and diversity and of modeling biodegradation, contaminant flux, and gaseous transport in the subsurface.