Sorption, Degradation, and Transformation in Soils and Sediments: Sinks Or Sources?

Sorption and degradation by soil often attenuate transport and persistence of chemicals, thus reducing the contamination of groundwater or stream water. However, processes within soils and sediments may not be sufficient to reduce contaminant concentrations, and in some cases, can lead to contaminants of greater concern. An overview of the soil processes that affect contaminant behavior will be briefly presented followed by relevant examples where the soil may not successfully attenuate. Examples will include several chemical classes such as fungicides, hormones, pharmaceutical, and perfluoroalkyl substances.  Management and remediation options towards minimizing contaminant transport and impact will be discussed where appropriate.