You are here:
STEAM INJECTION REMEDIATION IN FRACTURED BEDROCK AT LORING AIR FORCE BASE
Citation:
Davis*, E L. STEAM INJECTION REMEDIATION IN FRACTURED BEDROCK AT LORING AIR FORCE BASE. Presented at EPA Science Forum, Washington, DC, May 05 - 07, 2003.
Impact/Purpose:
To inform the public.
Description:
Contaminated groundwater occurs at many Superfund, RCRA, and Brownfields sites. Chlorinated solvents which can form a dense nonaqueous phase (DNAPL) when released to the subsurface can pose an extreme challenge for remediation, as DNAPLs are often difficult to locate and even harder to extract from the subsurface. Steam injection, which has been employed successfully for enhanced oil recovery, has proven to be very effective for the recovery of volatile and semivolatile contaminants from soils and groundwater. This project was the first research project on the injection of steam into fractured bedrock to recover DNAPL.
Contaminants in fractured rock present even greater challenges for remediation than soils due to the difficulty in understanding flow in fracture networks. At the same time, a large number of Superfund Sites throughout the country have a contaminated bedrock component. Research on remediation in these settings is needed to be able to address groundwater contamination at a large number of sites.
In partnership with the State of Maine, the Air Force, SteamTech Environmental Services, Inc., and the United States Geological Society, EPA ORD and Region I are conducting research on the recovery of volatile contaminants at the former Quarry site at Loring Air Force Base, in Limestone, Maine. EPA/ORD/NRMRL is taking a lead role in this research project through the Superfund Innovative Technology Evaluation (SITE) program and with the technical expertise of EPA researchers at the RS Kerr Environmental Research Center. In addition, experts from academia (University of California-Berkeley and Queen's University, Ontario, Canada) in fractured rock characterization and steam injection for remediation are part of the research team. The approach taken for this research was to fully characterize the hydrology and contaminant distribution of the fractured rock system on a discrete fracture basis, then to initiate steam injection. Extensive monitoring allowed the team to follow the progress of the steam injection, and daily samples of the effluent system allowed us to document the enhanced recovery from the steam injection. The enhanced contaminant recovery documented by this research project will aid in the development of this technology for remediation in the fractured rock setting. This project will also make recommendations for characterization needed at other contaminated bedrock sites.