Integrated Site-Wide Approach to Chlorinated Solvent Plume Remediation

摘要

The discovery of chlorinated volatile organic compounds (CVOCs) in the aquifer underlying a manufacturing facility prompted the initiation of an aggressive vol- untary site wide cleanup. Earth Tech, Inc. was selected to develop, design, construct, and operate a site-wide remedial strategy. Project challenges included multiple potential source locations in the unsaturated zone, the complexity of the groundwater flow regime, depth and concentrations of the CVOCs as high as 10,000 ppb, and working within an active third party manufacturing facility. Given a large number of potential source areas within the plant, delineation of CVOC impacts to the unsaturated zone was performed by the installation of an innovative soil vapor extraction system, rather than performing ex- tensive soil sampling within the operating manufacturing facility. In conjunction with the unsaturated zone treatment a comprehensive groundwater remediation system was de- signed and installed to provide plume capture under the most extreme groundwater flow conditions. In addition to the on-site remedial actions, off-site plume delineation was per- formed using direct push membrane interface probe (MIP) technology. Since installation, the site wide program has removed over 900 pounds of CVOCs from the unsaturated zone minimizing future impacts to the groundwater. In addition, the groundwater remediation system has removed or dechlorinated over 1500 pounds of CVOCs from the on-site groundwater, while preventing further off-site migration, all with minimal inter- ference to facility production. The site investigations conducted adjacent to the manu- facturing facility has identified several other off-site sources that have commingled in portions of the plume both up gradient and down gradient of the facility.