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To assess risks associated with dermal contact with surface soil and ingestion of surface soil, <br /> WRM included in the HHRA the soil sample analytical`results from soil borings SB-1, SB-1A, <br /> 4 and S15-3 through SBA 0 advanced during December 1999. From these soil borings, soil <br /> samples were collected from depths ranging from 5 to 20 feet bgs. The maximum detected <br /> concentration of each COC in soil.was selected as the representative concentration for that <br /> COC. As with the soil vapor analytical results, if a COC was not detected in the soil samples <br /> considered in the assessment,the laboratory detection limit was selected as the representative <br /> concentration for that COC. These soil sample analytical results are summarized in Table 1.' <br /> To assess potential risks associated with groundwater'dermal contact and ingestion, WRM <br /> # evaluated the groundwater analytical results from thepast four groundwater monitoring events <br /> conducted between September 27, 2007 and June 30, 2008. Except for 67.8 i{g/l of TPH-as- <br /> diesel in MW-3 on June 30, 2008, none of the COCs were detected at concentrations above <br /> laboratory reporting limits, during this period,. In the model; WRM selected the domestic well at <br /> 24500 South MacArthur Drive, located approximately 1,800 feet (549 meters) to the southeast of <br /> the site, as the point of contact. <br /> 4 <br /> A summary of the representative COC concentrations in soil, groundwater, and soil vapor are: <br /> r <br /> COC Soil Groundwater Soil Vapor <br /> Concentration Concentration Concentration <br /> (rnglkg) W11) (mglm3) <br /> TPH G 400 ND (50) ND (20) <br /> TPH D 1,800 67.8 nla <br /> Benzene 6.4. ND (0.5). ND (0.2) <br /> Toluene 16 ND (0.5) ND (0.2) <br /> Ethylbenzene 10' ND (0.5) ND (0.2) <br /> Total Xylenes 39 ND (1.0) ND (0.4) <br /> MTBE ND (0.5) ND (0.5) ND (0.2) <br /> Lead -8 nla nla <br /> ND-Not detected. The laboratory detection limit shown in parenthesis was selected as'the representative COC <br /> concentration. <br /> 12 <br />