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26 August 2013 AGE Project No. 95-0130 Page 2 of 9 Remediation Work Plan, dated 21 May 2003, and approved by the San Joaquin County Environmental Health Department (SJCEHD) by letter dated 10 June 2003. 2.1 . SOIL-VAPOR EXTRACTION REMEDIATION SYSTEM The SVE remediation system consists of 1) a 55-gallon moisture knockout vessel, 2) a 150 cubic foot per minute (CFM) regenerative vacuum blower, and 3) three 1,000-Ib GAC vessels for adsorption of contaminants of concern (COC) entrained in the soil-vapor stream. The SVE unit is connected to a total of five SVE wells (VW-1A/B, VW-2B, VW-31B and VW-4) via a manifold network of 2-inch subsurface PVC pipes extending from each SVE well location to the moisture knockout drum. Sampling ports are installed upstream of the moisture knockout chamber (influent), between the carbon vessels (intermediate), and downstream of the carbon vessels (effluent). The sampling port located downstream of the carbon vessels is utilized to recover effluent SVE soil-vapor samples, and is used to monitor the efficiency of hydrocarbon treatment. Additionally, influent and effluent streams are monitored routinely for the presence of organic vapors using an organic vapor meter (OVM) equipped with a photo-ionization detector (e.g. MiniRAE 2000; 10.0 eV; calibrated to isobutylene). In order to monitor efficiency of the SVE system; 1) a Magnehelic vacuum gauge and Dwyer DS-200 differential pressure sensor are installed priorto the inlet of the SVE system so that the incoming total soil-vaporflow rate can be monitored; the flow rate is determined from the measured differential pressure and the piping diameter when plotted on a nomograph (Appendix A), 2) SVE influent soil-vapor and effluent air flow streams were monitored routinely (i.e. weekly)for the presence of organic vapor using an organic vapor analyzer (OVA) equipped with a photo-ionization detector (PID: Thermo Environmental 580B; 10.0 eV; calibrated to isobutylene), and 3) influent soil-vapor and effluent air flow vapor stream samples are collected from sampling ports installed upstream (influent)of the SVE vacuum blower and downstream (effluent)of the SVE carbon vessels and submitted for laboratory analysis. Analytical results of SVE flow samples are summarized in Table 1. Field SVE measurements were recorded at regular intervals and are summarized in Table 2. 2.2. COLLECTION AND ANALYSIS OF VAPOR EXTRACTION AIR FLOW SAMPLES Three sets of influent/effluent SVE samples were collected on 23 April, 23 May and 17 June 2013. Soil-vapor extraction samples were collected from influent and effluent sampling ports located downstream and upstream of the carbon canister vapor recovery system. The influent and effluent samples were collected in Tedlar bags utilizing an electric Advanced GeoEnvironmental,Inc.