Understanding the processes controlling subsurface
transport is a key element in the demonstration of safe disposal of radioactive and/or hazardous wastes, as well as the design and implementation of effective
contaminant remediation. Subsurface transport is complex, controlled by the interplay among heterogeneous geologic environments, ground-water
flow, and physical/chemical interactions of dissolved and/or immiscible phase contaminants. Limited access to directly observe and sample the subsurface further
compounds this complexity. Transport processes control contaminant migration, as well as contaminant
retardation and isolation. Field-scale tracer testing is a
highly effective technology for determining controlling transport processes, as well as important transport parameter values for use in predictive models for regulatory compliance demonstration and remediation design.