Martin, C., C. Ross, R. Scott, C. Greene, J. Roberts, and A. Przepiora.
2018 Battelle Chlorinated Conference, April 8-12, 2018, Palm Springs, CA. Poster, 2018
Filed Under: Demonstrations
Filed Under: Demonstrations
At a former chemical facility, historical releases of the soil fumigant and pesticide chloropicrin contaminated an area of soil and groundwater. The compound is a strong irritant to the lungs and eyes and remediation challenges at the site included potential health and safety concerns related to chloropicrin emissions to ambient air during any soil removal. The complex geology of the treatment area, the presence of an active railroad spur located within a portion of the treatment area, and chloropicrin contamination in low-permeability soils in both the vadose and saturated zones also limited remediation options. To design an effective remedial strategy, bench-scale treatability studies of in situ chemical reduction with micro-scale zero-valent iron (MZVI) and enhanced in situ bioremediation (including KB-1® Plus augmentation) were tested on site soil and groundwater to assess treatment longevity in the subsurface, performance over the range of chloropicrin concentrations observed throughout the treatment area, and effectiveness at treating separate-phase chloropicrin. Based on treatability test results, the developed remedial approach for the saturated zone consisted of MZVI injection in higher concentration areas and emulsified ZVI combined with KB-1 injection in lower concentration areas. The remedy design also targeted chloropicrin in lower-permeability vadose zone soil using SVE in combination with sand-filled hydraulic fractures to enhance permeability. A phased approach was designed to assess performance of each treatment component while also mitigating downgradient migration of chloropicrin in groundwater.