In the USA, Western and Central Europe, there are many large-scale polluted sites that are too large to be cleaned up economically with available technologies. The pollution is caused by heavy industries to soils and sediments in waterways and reservoirs. Since these areas are expected to remain polluted for many years, it is necessary to take a long-term view to insure that the capacity to retain the contaminants is not diminished and to understand the potential for large-scale contaminant mobilization at these sites triggered by changing environmental conditions. This book provides information for predicting long-term changes and making risk assessments and describes the approach of geochemical engineering to handling large-scale polluted sites.