ABSTRACT
A Record of Decision (ROD) was issued in August 1995 for a 3-km long trichloroethene plume in a fractured basalt aquifer in Idaho, USA. The ROD identified pump-and-treat as the default remedy for the site; however, five alternative technologies were identified to be evaluated for their ability to replace or enhance traditional pump-and-treat for overall plume restoration. Integrating the default remedy with five technology evaluations required development of a plume restoration management strategy that maintained source area containment while completing the alternative technology evaluations. The process resulted in the decision by the regulatory agencies to replace pump-and-treat using enhanced in situ bioremediation in the residual source area and monitored natural attenuation for most of the dissolved-phase plume.
