Hazardous Substance Research Centers/South & Southwest

Overview of the Topic

A major cause of U.S. water pollution is contamination of sediments in rivers, lakes, harbors, and coastal waters. Environmental managers use several different methods to keep toxic chemicals in these sediments from being released into water and entering the food chain. One approach is to remove the pollutants by chemical or physical means. A less complex and costly--but less well proven--alternative is to isolate pollutants from the surrounding environment. One nonremoval technology showing special promise is in-situ capping, which seals off contaminated sediments under a layer (or layers) of soil, rock, or synthetic material.