The project consists of the implementation of engineering controls (vapor intrusion mitigation systems beneath building foundations) and institutional controls (land use covenant to restrict groundwater use and require vapor intrusion mitigation systems for new buildings) to remediate volatile organic compounds (VOCs), in soil gas and groundwater for the entire 5.2-acre Mora Drive (Site).
Past environmental investigations identified elevated concentrations of VOCs, primarily tetrachloroethylene and trichloroethylene, in soil, soil gas, and groundwater at the Site. Higher contaminant concentrations were detected at the Plessey Micro Science sub-area of approximately one acre, located at the northwestern portion within the 5.2-acre Site. In December 2016, the Department of Toxic Substances Control (DTSC) approved the Remedial Action Plan Amendment for Plessey Micro Science and selected remedies to mitigate VOC contamination in soil, soil gas, and groundwater. Subsequently, DTSC prepared the draft Removal Action Workplan, Mora Drive, proposing engineering controls and institutional controls to remediate the remaining VOC contamination in soil gas and groundwater at the Site.
See NOD for full details.