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�i Soil-Vapor Investigation Work Plan RMB GARAGE 715 North Hunter Street, Stockton, California 1.0. INTRODUCTION Advanced GeoEnvironmental, Inc. (AGE) has prepared this Soil-Vapor Investigation Work Plan as part of a soil-vapor investigation for the property located at 715 North Hunter Street, Stockton, California (site). The scope of work includes the advancement of three (3) shallow, soil borings for the installation of soil-vapor wells, collection of soil-vapor samples and preparation of a report. A Site Assessment Work Plan Addendum was previously prepared for this site, dated 05 November 2015. The purpose of the soil-vapor investigation is to evaluate the site under the State Water Resources Control Board - Low Threat Closure Policy (LTCP) and evaluate the overall potential of petroleum vapor intrusion into the building, located adjacent to the former underground storage tanks (UST) located in the sidewalk of Hunter Street. Additionally, field work will be performed utilizing guidance provided in the California Environmental Protection Agency (EPA) Department of Toxic Substances Control. Proposed soil borings will be advanced under San Joaquin County Environmental Health Department (SJCEHD) permit. The site and surrounding area are illustrated in Figure 1. Site structures and monitoring well locations are depicted on Figure 2. A geologic cross sections depicting petroleum impact to soil is illustrated in Figure 3. A plan view depicting the maximum extent of petroleum impact is depicted in Figure 4. As-built construction details of the soil-vapor sampling point and soil-vapor sampling setup are depicted in Figures 5 and 6. Analytical results of historical soil samples are summarized in Table 1. This work plan was prepared in accordance with the Path to Closure Plan, dated 16 August 2016 issued by the State Water Resources Control Board GeoTracker, that indicates a soil-vapor survey is needed to address the risk of petroleum soil-vapor intrusion on-site, as well as near monitoring well MW-5. 2.0. SCOPE OF WORK Due to petroleum-impacted soil documented at the site during the UST removal and subsequent investigation, the threat of potential soil-vapor intrusion into the building must be investigated. Additionally, high levels of contamination have been detected at monitoring well MW-5, near a residence. The State Water Resources Control Board has requested this investigation include the area near monitoring well MW-5. Therefore, AGE is proposing to drill and install three soil-vapor points and sample (SV-1 through SV-3) to characterize potential soil-vapor intrusion on-site and across Hunter Street on the sidewalk near monitoring well MW-5. The proposed locations for SV-1 through SV-3 are located to assess soil-vapor near the eastern side of the property building and the former UST release area, and across the street on the western side of the residence near monitoring well MW-5. Drilling and field activities will consist of the following tasks: Advanced GeoEnvirmnmenlal,La.