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TCA ranged from<1.2 to 5300 ppbv <br /> DCA ranged from<1.2 to 620 ppbv <br /> PCE ranged from<1.2 to 460 ppbv <br /> TCE ranged from<1.2 to 520 ppbv <br /> DCE ranged from<1.2 to 680 ppbv <br /> Soil vapor concentration results for cis-1,2-DCE,trans-1,2-DCE,and 1,2-DCA ranged from<1.2 <br /> to 4.8 ppbv except for one sample(SV- 11-15 feet, which had a concentration of 69 ppbv of cis- <br /> 1,2-DCE. Based on the very low concentrations of cis-1,2-DCE, trans-1,2-DCE,and 1,2-DCA <br /> detected(with one exception,described above),these target analytes were not considered <br /> constituents of concern at the LNC site by Geomatrix(2006). <br /> Shallow soil gas samples were collected from all the borings at a depth of about 6 feet bgs.The <br /> results of these samples are shown on Figure 9. In general,the highest concentrations of VOCs <br /> detected from shallow soil gas samples were from borings located in the vicinity of Area A, <br /> south of the the southern Lustre-Cal building,and the Concrete Tank Area(Figure 9).The <br /> highest concentration of a VOC detected in the 6 foot samples was from sample SV-7-6 foot, <br /> collected in the Concrete Tank Area with a concentration of TCA at 5,300 ppbv(Figure 9). Soil <br /> gas samples collected from Area B,Area C,and Area D contained relatively low concentrations <br /> of VOCs. <br /> The January 2005 California Human Health Screening Levels(CHHSLs)for soil gas <br /> concentrations at commercial/industrial land use sites are shown in Table 1. CHHSLs were <br /> developed as a means of screening VOC concentrations in shallow soil vapor samples <br /> (approximately 4.5 feet bgs). Several of the 6-foot samples had concentrations of PCE that <br /> exceeded the CHHSL for PCE. These included samples collected from borings SV-10,SV-11, <br /> SV-12,and SV-14,which were located on the southern portion of the LNC site. <br /> M ainU)-.%nvuonmontsMNC1110152007.wpd 27 <br />