SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

New West Petroleum • - 5 - • 26 November 2012 6437 Banner Street Lodi, San Joaquin County Public Participation Public participation was conducted from 23 October 2011 to 23 November 2011 with no adverse comments received by this agency. SJCEHD is in agreement with the closure. Low Risk Closure Policy (LTCP) Review The Site qualifies for a low risk closure under the State Water Resources Control Board Low Risk Closure Policy, based on the following rationale: Groundwater Specific Criteria 1.5. The regulatory agency determines, based on an analysis of site specific conditions, that the site under current and reasonably anticipated near-term future scenarios, the contaminant plume poses a low threat to human health and safety and to the environment and water quality objectives will be achieved within a reasonable time frame. See above Table 1 and Sensitive Receptors section. Petroleum Vapor Intrusion to Indoor Air. Exemption - Active Commercial Petroleum Facility. Soil vapor samples were collected between the USTs and an adjacent fast food restaurant. The November 2007 Human Health Risk Assessment reviewed the soil vapor and monitoring data, and concluded risks from soil, soil vapor, and groundwater as a contributor to vapor migration into nearby buildings was insignificant. Direct Contact and Outdoor Air Exposure. Exemption — The upper 10 feet of soil is free of petroleum contamination. 3.2 A site specific risk assessment demonstrates the maximum concentrations of petroleum constituents in soil will have no significant risk of adversely affecting human health (i.e., `passes'). The Regional Board staff closure recommendation was also made by review of the site specific data and professional judgment prior to implementation of the LTCP. Summary and Recommendations The RPs have complied with all of the requirements in the Regional Board CAO R5-2007-0709, staff letters and directives, and the Low Threat Closure Policy, and have adequately assessed and remediated MTBE- impacted groundwater associated with the Site release. As evidenced by declining concentrations in groundwater, the residual contamination beneath the subject site will continue to attenuate in place, poses a minimal risk to municipal supply well CSA-31-2, and will not pose a threat to human health and/or the environment. Based on the minimal residual contamination in groundwater, lack of threats from soil or soil vapor intrusion, declining groundwater