Wetland-mediated destruction of chlorinated VOCS
Document Type
Conference Proceeding
Publication Date
12-1-2002
Abstract
Historic use of a site in the northeastern USA as a waste chemical reclamation facility for approximately 20 years resulted in the release of chlorinated solvents (CVOCs) and other contaminants to the subsurface. DNAPL has been observed in some locations. Groundwater beneath the site ultimately discharges to a nearby wetland. Historically, contaminant plumes migrated from the DNAPL source area and discharged to the wetlands. Existing data from the site suggest that biodegradation of chlorinated ethanes and ethenes is occurring beneath and downgradient of the Site Operations Area (SOA). Specifically, DNAPL samples from the SOA indicate that the source material responsible for the groundwater plumes is comprised of tetrachloroethene, trichloroethene, 1,1,1-trichloroethane, BTEX (benzene, toluene, ethylbenzene, and xylenes), petroleum hydrocarbons, and PCBs. Water samples from monitoring wells, however, contain not only these compounds, but also their biodegradation products such as dichloroethene, dichloroethane, and vinyl chloride. In order to determine the relative roles of the groundwater and wetland systems in degrading the CVOCs, a natural attenuation study was conducted that included specific sampling programs targeting the groundwater and wetland systems. Results of the study indicated that the petroleum hydrocarbons in the DNAPL provided a source of carbon to the groundwater system, thus promoting the creation of conditions favorable for reductive dechlorination. Contaminant and attenuation parameter profiles beneath and across the wetland root zones demonstrated strong evidence for additional degradation of the remaining CVOCs. The naturally occurring organic carbon of the wetland soils, combined with the mixed aerobic/anaerobic environments appeared to facilitate the efficient mineralization of the CVOCs.
Publication Source (Journal or Book title)
Proceedings of the Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds
First Page
1527
Last Page
1534
Recommended Citation
Herberich, J., Johnson, C., LaChance, J., & Pardue, J. (2002). Wetland-mediated destruction of chlorinated VOCS. Proceedings of the Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds, 1527-1534. Retrieved from https://repository.lsu.edu/civil_engineering_pubs/1026