Expedited response action proposal for 316-5 process trenches

A summary of the evaluation of remedial alternatives for the 300 Area Process Trench sediment removal at Hanford is presented. Based on the preliminary technology screening, screening factors, and selection criteria the preferred alternative for the 300 Area Process Trench is to remove and interim stabilize the sediments within the fenced area of the process trenches. This alternative involves proven technologies that are applied easily at this mixed waste site. This alternative removes and isolates contaminated sediments from the active portion of the trenches allowing continued used of the trenches until an inspection and treatment facility is constructed. The alternative does not incorporate any materials or actions that preclude consideration of a technology for final remediation of the operable unit. The estimated initial and annual costs would enable this alternative to be implemented under the guidelines for an EPA- funded ERA ($2 million). Implementation of the alternative can be accomplished with trained personnel using familiar procedures to provide a safe operation that accomplishes the objective for removing a potential source of contamination, thereby reducing potential environmental threat to groundwater. 18 refs., 5 figs., 9 tabs