In Situ Bioreactor (ISBR) systems were utilized at a closed hazardous waste management site in South Carolina to evaluate their performance in remediation of soil impacted with chlorinated hydrocarbons. The ISBR test system consists of two 4-inch ISBRs installed to a total depth of ~40’ bgs, supplied by a regular feed of air and nutrients to promote microbiological colonization and degradation of chlorinated volatile organic compounds. The study results indicated that soil concentrations were reduced during the first performance evaluation period from 2,000 mg/kg to below 100 mg/kg. The field pilot study included two ISBR units deployed in two separate areas of notable soil effect. Tetrachloroethylene concentrations have been reduced by 82% at the 5’ level and 99% at the 15’ level within the location where drums of waste were stored. At a second waste processing area, tetrachloroethylene concentrations were reduced by 92% at the 20’ level and 98% at the 35’ level.