Otto, C.J., and Townley, L.R. (1997), Feasibility of a dual pump recovery (DPR) system to recover a dense plume, IAH XXVII Congress, Groundwater in the Urban Environment, Nottingham, UK, 21-27 September, 4pp.

A leaking point source located in an urban area has resulted in a dense plume composed mainly of ammonium sulfate. The contaminant has accumulated in the bottom of a regional unconfined sandy limestone aquifer system. With a current conventional single-pump system of four recovery bores it would take 17 years to remediate the aquifer. The main limitation of the current remedial strategy is that the efficiency of recovery is decreasing due to downconing of the dense/freshwater interface and increasing dilution by freshwater. A dual pump recovery (DPR) system has been developed to enhance the efficiency of recovery operations and to reduced the duration of remediation. Results are presented for DPR trials in two adjacent bores and a single bore. It is estimated that a DPR system can halve the recovery time.