ABSTRACT
Assessment and successful remediation of arsenic contaminated sites requires a rigorous understanding of the factors influencing arsenic fate and transport as well as the ability to predict the behavior of arsenic in soil and aquifer systems under future conditions. The fate of arsenic in both naturally and anthropogenically impacted aquifer systems, however, is determined by interactions between physical, chemical, and biological processes. In many cases it can be difficult to discern or distinguish between specific geochemical or biogeochemical processes controlling the fate of arsenic, or whether its fate in fact might be predominantly controlled by physical transport. The underlying causes of elevated arsenic concentrations will generally vary from case to case and can be affected by several site-specific factors including the nature and magnitude of historical or ongoing releases, the chemical and mineralogical composition of the aquifer matrix, the composition of the ambient groundwater and hydrogeological conditions.
