Regulatory Requirements/Cleanup Goals:
- The objective of this field demonstration was to evaluate the effectiveness of ERH in reducing the concentration of chlorinated solvents in groundwater. Performance of the system was evaluated by monitoring the ability of the system to: heat the soil in the study area; increase the removal rate of contaminants, as compared to previous ERH tests conducted at the site; effectively remove VOCs from the soil and groundwater
- Goals for the site, established in the ROD, were - PCE - 0.005 mg/kg groundwater and 4 mg/kg soil; TCE - 0.005 mg/kg groundwater and 0.015 mg/kg soil; and PCA - 0.052 mg/kg groundwater and 0.1 mg/kg soil |
Results:
- Estimated mass of TCE, PCE, and PCA removed in the off-gas was 1,385 lbs
- The ERH system reduced groundwater concentrations of PCA, PCE and TCE an average of 49 percent, 75 percent and 56 percent; however, at the end of the field demonstration, concentrations of PCA, PCE, TCE, and cis-1,2-DCE were above the remedial action objectives
- The ERH system reduced soil concentrations of PCA and PCE to below the remedial action objectives; however, TCE concentrations remained above the remedial action objective |
Description:
Fort Richardson, established in 1940 as a military staging and supply center during World War II, is located approximately 10 miles northeast of Anchorage, Alaska and occupies about 56,000 acres. Its current mission is to provide services, facilities, and infrastructure to support the rapid deployment of Army forces. The site was added to the National Priority List (NPL) in June 1994 and the site cleanup is being addressed under a Federal Facilities Agreement (FFA) to address contamination at the site. The Poleline Road Waste Disposal Area (PRDA) was used as a disposal area from 1950 to 1972. Results of a site investigation that soil and groundwater has been contaminated with chlorinated solvents including TCE, PCE, and TCA.
ERH was evaluated as a potential remediation technology for the site. This report describes the field demonstration of ERH performed from July through October 1999, conducted in Area A-3 of the PRDA, using heating arrays labeled 4, 5, and 6. The field demonstration covered a treatment area of approximately 110 feet long by 50 feet wide by 35 feet deep. The ERH system was constructed in three phases, with each phase including an electrode array (seven electrodes installed to a depth of 38 feet), three SVE wells, and two thermocouples installed in each phase. The ERH system reduced contaminant concentrations in groundwater by as much as 75 percent. However, at the end of the demonstration, PCA, PCE, TCE, and cis-1,2-DCE were above the remedial action objectives. PCE and PCA concentrations in soil were reduced to below the remedial action objectives; however, TCE concentrations remained above the goal. |
