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In Situ Thermal Remediation
Citation:
Davis, E. In Situ Thermal Remediation. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-23/062, 2023.
Impact/Purpose:
The purpose of this paper is to briefly describe these commonly used in situ thermal remediation technologies, and how they are deployed to remediate VOC and SVOC contaminated sites. The effects of temperature on the physical properties of common organic contaminants that result in the effectiveness of these technologies for the recovery or destruction of contaminants are also briefly described. A case study is provided for each of the thermal technologies discussed. In addition, guidance is provided on evaluating, contracting, and implementing thermal technologies within the Superfund process of evaluating alternative technologies, including preparing bid documents for thermal remediation services, reviewing designs, and monitoring the implementation of the remedy.
Description:
In situ thermal remediation technologies rely on the addition of energy to the subsurface to change the phase distribution and other physical properties of volatile and semivolatile organic contaminants to mobilize them and aid in their recovery. The most used in situ thermal remediation technologies today are Steam Enhanced Extraction (SEE), electrical resistance heating (ERH), and thermal conductive heating (TCH; sometimes called in situ thermal desorption, ISTD). These three technologies are applicable to and have been proven for a wide variety of organic contaminants and in a wide variety of hydrogeologic settings, both above and below the water table. Thermal remediation technologies are very aggressive and are most applicable for contaminated sites (or portions of sites) where contaminant concentrations are the greatest, generally areas where nonaqueous phase liquids (NAPLs) are present. The purpose of this paper is to briefly describe these commonly used in situ thermal remediation technologies, and how they are deployed to remediate VOC and SVOC contaminated sites. Advice based on experience gained from sites where these technologies have been implemented is provided on soliciting thermal remediation services, how to determine the area/volume to be treated, and when to terminate the heating portion of the remediation. This paper includes both information gathered from other published papers and knowledge gained from the author’s extensive experience of technical support for thermal remediation.