Targeted Injections to Accelerate Remedial Completion at a Large-Scale Combined CVOC Bioremediation/Thermal Remediation Site

摘要

Background/Objectives. Historical releases of chlorinated solvents occurred from a former manufacturing facility in Connecticut resulting in concentrations of chlorinated volatile organic compounds (CVOCs) in source zone groundwater of up to 780 ppm and concentrations of over 20 ppm in the resulting 15-acre downgradient groundwater plume. Source area residual dense non-aqueous phase liquid (DNAPL) and CVOCs were situated in tight soils (till) and weathered bedrock. The majority of the off-site CVOC groundwater plume is located within a forested wetland where the soils are more permeable than in the source area. The primary contaminant of concern was trichloroethylene (TCE) although other CVOCs persisted in groundwater. The final multi-faceted remedial solution was a large-scale project incorporating limited source zone excavation followed by source zone in situ electrical resistance heating (ERH), and extensive plume-wide in situ bioremediation utilizing enhanced reductive dechlorination (ERD) and bioaugmentation.