A relatively stagnant groundwater plume of PCE presents a vapor intrusion risk to the existing dry cleaning facility and adjacent businesses. Evidence of complete reductive dechlorination of PCE was observed over a relatively short time period and Dhc inoculation appears to have been successful.
Millbrea, California
TRC
Jiffy Cleaners is a dry cleaning facility located in Millbrae, California that is underlain by groundwater impacted with tetrachloroethene (PCE). Several small spills occurred in the vicinity of the dry cleaning machine during of the early years of operation, which date back to the 1960s. Although PCE impacts to underlying soil have attenuated over time, a relatively stagnant groundwater plume of PCE presents a vapor intrusion risk to the existing dry cleaning facility and adjacent businesses.
The objective of this pilot test was to demonstrate flux reduction of TCE downgradient of an EHC® Liquid permeable reactive barrier (PRB). The flux calculations demonstrated a 73% reduction in 8 months. Advanced techniques such as real-time monitoring, microbial characterization and diagnostics and hi-res imaging were used to characterize and track remedial progress.
Groundwater was is impacted with chlorinated solvents (primarily PCE, TCE and 1,2-DCE). A pilot test was first conducted in Nov 2011 by injecting EHC® Liquid reagent into the shallow aquifer. PCE and TCE concentrations were reduced to concentrations below the GWQS within 9 months following the pilot-scale treatment.
The objective of the project was to demonstrate the efficacy of EHC® Liquid Injections for treatment of residual TCA and DCE contamination with limited access beneath the building and to reduce contaminant mass in the deeper saturated zone (20-25 ft bgs).
