CHEMICAL OXIDATION OF A CHLORINATED SOLVENT GROUNDWATER PLUME USING SEGMENTED INJECTION WELLS

Fenton-based chemical oxidant injections using segmented injection wells and direct push injection points were performed to remediate a volatile organic halocarbon groundwater plume at a former dry cleaning facility in South Florida. The remediation included a pilot test and three large-scale injections. Tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, trans-1,2- dichloroethene, and vinyl chloride were the principal volatile organic halocarbon contaminants targeted for remediation. Total volatile organic halocarbon concentrations were as high as 100,111 ug/l in source area wells. Following a pilot test involving six injection wells, an additional twenty-five injection wells were installed in the areas of highest contaminant concentration. In addition, a direct push drill rig was used to complete injections downgradient and within the apparent contaminant source area during the large-scale remediation. The remediation has reduced total volatile organic halocarbon concentrations by 88 percent. Tetrachloroethene and trichloroethene concentrations were reduced by 98 and 94 percent, respectively.