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16 October 2006 <br /> AGE-NC Project No. 98-0520 <br /> Page 4 of 10 <br /> ' hydrocarbon-impacted ground water samples collected at the site for the last 8 quarters. Table 3 <br /> provides the complete history of ground water sampling analytical results from the site. <br /> The shallow soil vapor samples collected at the site during the soil vapor extraction pilot test was' <br /> ' reported to be below detectable levels for all listed SFBRWQCB ESL constituents of concern(TBA, <br /> 1,2-DCA and EDB were not analyzed in the soil vapor samples).The below detectable levels for soil <br /> t vapor samples were below all applicable ESLs.Table 4 provides a comparison of the SFBRWQCB <br /> ESLs to site concentrations of soil vapor samples. Appendix A includes a table of five soil vapor <br /> samples collected from vapor extraction well VW-1 in September 2005. <br /> The data for the site provided in Table 4 was used for input in RISC WorkBench modeling for both <br /> p g <br /> volatilization from ground water to outdoor air and volatile air emissions from soil to indoor air. <br /> Constituents of concern modeled for volatilization fromg round water to outdoor air included <br /> ethyl-benzene,toluene, TPH aromatic C8-10,TPH aromatic C10-12, and xylenes.Additional input <br /> ' provided for fate and transport modeling for volatilization from ground water to outdoor air <br /> included: <br /> • Simulation time: 100 years. <br /> • Total soil porosity: 0.25 centimeter cubed per centimeter cubed (cm3/cm3). <br /> ' 0 Water content: 0.15 cm3/cm'. <br /> • Thickness of capillary fringe: 50 cm. <br /> • Air content in capillary fringe: 0.005 cm3/cm3. <br /> • Water content in capillary fringe: 0.24 cm3/cm3. <br /> ' Distance from ground water to surface: 4.9 meters. bTW eu 14 ' <br /> • Lens thickness: 6.0 meters. <br /> • Total porosity in lens: 0.25 cm3/cm3. <br /> • Water content in lens: 0.15 cm3/cm3. <br /> Additional input parameters including building input parameters are included in Appendix F. <br />' The RISC WorkBench modeling for volatilization from ground water to outdoor air results for were <br /> steady-state models as follows: <br /> Advanced GeoEnvironmental,Inc. <br />