In situ Permeable Reactive Barrier for the Treatment of Hexavalent Chromium and211 Trichloroethylene in Ground Water. Volume 2. Performance Monitoring

摘要

A 46 meter long, 7.3 meter deep and 0.6 meter wide reactive barrier was installed211u001eat the U.S. Coast Guard Support Center (USCG) in Elizabeth City, North Carolina, 211u001ein June 1996. The reactive barrier was designed to remediate a hexavalent 211u001echromium (Cr(VI)) groundwater plume, in addition to treating portions of a larger 211u001eand not yet fully characterized trichloroethylene (TCE) groundwater plume at the 211u001esite. The barrier is composed of Peerless Metal and Abrasives of Detroit, 211u001eMichigan (Peeerless) granular iron and removes (Cr(VI)) and TCE from the 211u001egroundwater via processes of reduction and precipitation, and reductive-211u001edechlorination, respectively. In addition to nine large-screen compliance wells, 211u001ea monitoring network of approximately 150 small-screen sampling points was 211u001einstalled in November 1996 to provide detailed information on changes in 211u001eporewater geochemistry through the barrier. This network was sampled seven times 211u001ebetween November 1996 and December 1998 at 3 to 6 month intervals: November 1996, 211u001eFebruary 1997, June 1997, September 1997, March 1998, June 1998 and December 211u001e1998.