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Table 5 <br /> Summary of Indoor Air Modeling Results <br /> Chevron Facility#306620 (Former Unocal#5098) <br /> 5400 and 5606 Pacific Avenue, Stockton, California <br /> MAXIMUM SOIL LOCATION OF HYPOTHETICAL FUTURE <br /> COMPOUND' VAPOR MAXIMUM SOIL ONSITE RESIDENTIAL CURRENTIFUTURE ONSITE <br /> CONCENTRATION' VAPOR BUILDING COMMERCIAL/INDUSTRIAL BUILDING <br /> (ug/m3 CONCENTRATION ELCRZ HI ELCRZ HIZ <br /> Benzene 64.5 SV-1 2.0E-07 2.6E-04 5.8E-08 9.3E-05 <br /> C5-C8 Aliphatic=° 4,000 SV-1 NC 1.6E-03 NC 5.6E-04 <br /> C8-C10 Aliphatics' 690 SV-1 NC 6.3E-04 NC 2.2E-04 <br /> Total ELCR/HI: 2.0E-07 2.4E-03 5.8E-08 8.7E-D4 <br /> HYPOTHETICAL FUTURE <br /> TICS SOIL VAPOR LOCATION OF SOIL ONSITE RESIDENTIAL CURRENT/FUTURE ON-SITE <br /> CONCENTRATION VAPOR BUILDING COMMERCIAL/INDUSTRIAL BUILDING <br /> (ppbv) CONCENTRATION ELCRZ Hl' ELCRZ HIZ <br /> C5-C8 Aliphatics 126,500 SV-1 NC 2.4E-01 NC 8.4E-02 <br /> C9-C18Aliphatics 12,400 SV-1 NC 8.1E-02 NC 2.9E-02 <br /> Total HI: NC 3.2E-01 NC 1.1E-01 <br /> EXPLANATION: <br /> DTSC/HERD= Department of Toxic Substances Control/Human and Ecological Risk Division. <br /> ELCR= Potential Excess Lifetime Cancer Risk <br /> HI = Potential Hazard Index <br /> NC= Not calculated;dose-response values not available. <br /> TIC= Tentatively identified compounds. <br /> 'Compounds evaluated using indoor air modeling include those detected <br /> above the California Human Health Screening Level(CHHSL)(CaIEPA,2005 and CaIEPA,2009). <br /> 2Estimated using the CaIEPA DTSC/HERD version of the Johnson and Ettinger Model Spreadsheets(2004). <br /> 3Maximum soil vapor concentrations for all listed compounds were detected during the September 9,2010 sampling event. <br /> "Maximum soil vapor concentration detected in May,September,and October 2010 sampling events(based on data tables presented <br /> in report text. <br /> =Represents Tentatively Identified Constituents(TICS)from September 9,2010 sampling event within the associated carbon fraction range. <br /> Individual TIC results are presented in the report text.TICS within each of the presented carbon fraction ranges <br /> were then summed to determine the soil vapor concentration within each of the carbon fraction ranges.These carbon fraction ranges <br /> were chosen for evaluation since recommended toxicity criteria are available for these and not for the individual TICS. <br /> TICS are evaluated separately from detected compounds since there may be overlap between constituents included within the <br /> C6-C8 and C8-C10 carbon ranges and the TICS evaluated. <br /> 60146576 4 of 4 AECOM <br />