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4.8 2006 Soil Gas Survey <br /> LNC retained Geomatrix to conduct a soil gas survey of the LNC site at 110 East Turner Road <br /> during 2006 as part of its effort to investigate VOCs within the soil at the LNC site. This work <br /> was conducted under the oversight of the RWQCB. <br /> Between October 16 and 20,2006,Geomatrix advanced 14 soil borings(SV-1 through SV-3 and <br /> SV-5 through SV-15)at locations shown on Figure 8. Drilling activities were conducted by <br /> Precision Sampling,Inc.,of Richmond,California,using a trailer mounted direct push rig. Soil <br /> vapor samples were collected at depth intervals of approximately 6, 10,and 15 feet bgs for <br /> shallow borings. Samples from deeper borings(SV-1,SV-6,SV-7,and SV-14)were collected at <br /> depth intervals of 6,20,and between 26 and 29 feet. The samples collected from between 26 and <br /> 29 feet were planned to be collected from approximately a 40-foot depth. However,refusal of <br /> the direct push drive rod was encountered,so in each of the deep borings, a soil gas sample was <br /> collected at the greatest depth reached. <br /> Soil gas samples were collected using Summa canisters provided by Air Toxics, Inc., of Folsom, <br /> California. Soil vapor samples were analyzed for VOCs by U.S. Environmental Protection <br /> Agency(USEPA)Test Method TO-15 for the following list of analytes:TCA,DCA,PCE, <br /> TCE,cis-1,2-dichloroethylene(cis-1,2 DCE), trans-1,2-dichloroethyleno(trans-1,2 DCE),DCE, 1 <br /> ,2-dichloroethane(1 ,2-DCA),and 2-propanol. These VOCs(other than the 2-propanol)were <br /> selected as target analytes because these chemicals were detected at multiple locations in <br /> previous soil vapor and soil samples(WZI, 1996). <br /> At least one target analyte was detected in each of the soil vapor samples collected and <br /> analyzed(Geomatrix,2006).The soil vapor analytical results range in analyte concentrations are <br /> summarized below. <br /> M einAD:\Hnvironm=tdV.N CAV 0152007.wpd 26 <br />