Remediation of recalcitrant compounds at sites with high concentrations of volatile organic com- pounds (VOCs) or nonaqueous-phase liquids (NAPLs) can present significant technical and financial (long-term) risk for stakeholders. Until recently, however, sustainability has not been included as a significant factor to be considered in the feasibility and risk evaluation for remediation technologies. The authors present a framework for which sustainability can be incorporated into the remediation selection criteria focusing specifically on off-gas treatment selection for soil vapor extraction (5VE) remediation technology. SVE is generally considered an old and standard approach to in situ reme- diation of soils at a contaminated site. The focus on off-gas treatment technology selection in this article allows for more in-depth analysis of the feasibility evaluation process and how sustainable practices might influence the process.
SVE is more commonly employed for recovery of VOCs from soils than other technologies and generally employs granular activated carbon (GAC), catalytic, or thermal oxidation, or an emerging alternative technology known as cryogenic-compression and condensation combined with regenerative adsorption (C3-Technology). Of particular challenge to the off-gas treatment selection process is the potential variety of chemical constituents and concentrations changing over time. Guidance is available regarding selection of off-gas treatment technology (Air Force Center for Environmental Excellence, 1996; U.S. Environmental Protection Agency, 2006). However, there are common shortcomings of off-gas treatment technology guidance and applications; practitioners have rarely considered sustainability and environmental impact of off-gas treatment technology selection. This evaluation includes consideration of environmental sustainability in the selection of off-gas treatment technologies and a region-specific (Los Angeles, California) cost per pound and time of remediation comparisons between GAC, thermal oxidation, and C3-Technology. ©2008 Wiley Periodicals, Inc.