SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Technical Memorandum Proposed Performance Goals for Soil Vapor Extraction Systems Lodi Groundwater Plume Lodi, California Revised April, 1996 1. BACKGROUND AND PURPOSE This technical memorandum summarizes proposed performance goals for soil vapor extraction (SVE) systems that will be installed at individual sites located within the downtown area of Lodi, California. These sites have been identified by regulatory agencies as being associated with the Lodi Groundwater Plume. SVE technology has been identified by both regulatory agencies and responsible party consultants as the most cost effective and technically practicable means to remediate several types of volatile organic compounds (VOCs) identified by past investigations as being present within the vadose zone of each site. These VOCs may be present in both the liquid and vapor phase or the vapor phase only. Operation of the SVE systems at each of the sites is expected to reduce the VOC mass contained in the vadose zone. Residual VOCs in the vadose zone near the soil/water interface may be due to capillary effects and degassing of dissolved VOCs contained in the groundwater. For these reasons, the SVE systems, particularly those which extend to a short distance above the water table, may not remove VOC levels in the soil to nondetectable concentrations or to concentrations equivalent to drinking water maximum contaminant levels. The overall objective of this Technical Memorandum is to establish a framework of SVE performance goals based on baseline data from pilot studies, initial SVE operational performance results, and post SVE monitoring results that will allow responsible party and regulatory agency agreement on SVE system termination. Workplans for pilot test and full scale SVE remediation will include quality assurance/ quality control sampling procedures for soil gas as previously specified by California Environmental Protection Agency, Department of Toxic Substances Control (DTSC) staff. i