This comprehensive reference describes investigations of the fate of toxic chemicals emanating from hazardous waste sites and contaminating groundwater, discussing the hydrogeochemistry at US, Canadian, Australian, and German sites to reflect different approaches used worldwide. Written by over 30 international experts, it presents case histories spanning 30 years of USGS Organics in Water work, outlines EPA SW-846 analytical methods for groundwater at hazardous waste sites, details analytical requirements for surveys and compliance, examines statistical and data-interpretation techniques, and covers field tools and processes such as gas chromatographs, DNAPL dissolution, biotransformation, and sorption to aquifer materials. Extensively illustrated with more than 250 figures, tables, and equations, it is a practical tool for pollution control and environmental engineers, hydrogeologists, analytical chemists, and advanced students.