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4 31 Soil Sampling <br /> An EMCON field geologist observed Woodward Dnlling of Rio Vista, California, drill two <br /> off-site soli borings to a depth of 515 and 60 feet bgs The borings were converted to vapor <br /> extraction wells VW-12 and VW-13 Groundwater was not encountered during drilling <br /> activities EMCON's field procedures are presented in Appendix A <br /> Soil samples were obtained at approximately 5-foot intervals for possible laboratory analyses <br /> and to characterize the geology beneath the site The samples were logged using visual and <br /> manual methods and classified according to the Unified Soil Classification System. Sediments <br /> encountered are shown on the logs of bongs (see Appendix B) Drill cuttings were stockpiled <br /> on site, placed on, and covered with plastic sheeting <br /> On June 7, 1995, an EMCON geologist collected soil samples (one composite of four samples) <br /> from the stockpiled soil for analyses to evaluate disposal options At ARCO's request, the drill <br /> cuttings were transported by Dillard Trucking of Byron, Calnforiva, to the BFI, Class 11 landfill <br /> in. Livermore, California, for disposal <br /> 4 3 2 Soil Testing <br /> Select soli samples collected from the wells and stockpiled soil were analyzed for total <br /> purgeabie petroleum hydrocarbons (equivalent to total petroleum hydrocarbons as gasoline <br /> [TPHG]) using U S Environmental Protection Agency (USEPA) Method 5030/8015, total <br /> extractable petroleum hydrocarbons (equivalent to total petroleum hydrocarbons as diesel <br /> [TPHD]) using USEPA Method 3350/8015, benzene, toluene, ethylbenzene, and total xylene <br /> isomers (BTEX) using USEPA Method 5030/8020, and total oil and grease (TOG) using <br /> USEPA Methods 5520 B and F In addition, stockpiled soil samples were analyzed for soluble <br /> threshold lunt concentration for seventeen metals using the Waste Extraction Method, volatile <br /> organics using USEPA Method 8240, sernivolatile organics using USEPA Method 8270, and <br /> reactivity, corrosivity, and Ignitability The samples were analyzed at Sequoia Analytical in <br /> Sacramento, California (California Department of Health Services, Hazardous Waste Testing <br /> Laboratory, Certification No 1624) Analytical results and chain-of-custody records are <br /> presented in Appendix C <br /> 4 3 3 Analytical Results <br /> Concentrations of TPHG, TPHD, and BTEX were below laboratory detection in soil samples <br /> analyzed from the wells TOG was detected in sod samples collected from well VW-12 at <br /> 315 feet bgs at a LonLentration of 96 parts per million (ppm) but was not detected in the other <br /> soil samples Results of the laboratory analyses are presented in Table 4 <br /> SA(W V'J0N0805080514204BS 97\prz I Rev 0 3112/97 <br /> 20805 142 004 4-4 <br />