Operation and Analysis of the BEHIVS System at Edwards Air Force Base

Abstract

Abstract : The bioenhanced in-well vapor stripping (BEHIVS) system involved two innovative technologies in combination, cometabolic bioremediation and in-well vapor stripping, for treatment of a source of trichloroethene (TCE) contamination in groundwater. This system concept evolved from former demonstrations of each technology alone at Edwards Air Force Base (AFB). A realization of the potential of using these two technologies in combination to treat a high-concentration source of TCE arose from the successful results of each of these processes for in-situ treatment of a lower concentration TCE groundwater plume at Edwards Air Force Base Site 19 (McCarty et al., 1998; Gorelick and Pinto, 1997.) Funding was subsequently received from the Strategic Environmental Research and Development Program (SERDP) of the Department of Defense for construction of a BEHIVS system to treat the TCE source at Site 19, where TCE concentrations as high as 8 mg/L occur. SERDP also provided funds for the construction of an extensive monitoring system so that the BEHIVS performance could be thoroughly evaluated. The construction of the BEHIVS and associated monitoring systems neared completion at the end of December 2000, with additional support from Edwards AFB through their contractor, Earth Tech, Inc. Funds for operation and evaluation of the system were then requested from Edwards AFB, and a subcontract for this purpose was received on June 27, 2001, by Stanford University from Earth Tech, Inc. This final report summarizes the results of operation of the BEHIVS system at Edwards Air Force Base, numerical modeling analysis of the results, study conclusions, and recommendations for application of the BEHIVS system elsewhere as well as for remediation of the chlorinated solvent contamination at Site 19.