Combined Remediation Using Chemical Oxidation and Bioremediation Treats Recalcitrant Organic Contaminants at a Complex Site

摘要

Background/Objectives. A specialty chemicals manufacturing facility identified with predominantly VOC-and SVOC-contaminated soils and groundwater has been successfully remediated using a combined remedy approach. Both chemical oxidation and bioremediation were implemented with a single product application to address residual contaminant mass that could not be removed with traditional excavation. Historical site investigation activities identified five areas of soil contamination and a groundwater plume including free product (LNAPL). Air sparge, soil-vapor extraction, soil excavation, and ISCO technologies were previously implemented at the Site and effectively remediated the majority of impacted soils, and significantly reduced the size of the groundwater plume. However, samples recently collected indicated that soil exceeding applicable risk-reduction standards (RRS) remained in one area of the site within the footprint of the groundwater plume. Significant contaminants identified in the groundwater include benzene, xylenes, 1,2-dichlorobenzene, 1,4-dioxane, acetone, naphthalene, 4-methyphenol, and the chlorinated herbicide 2,4-D.