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h <br /> . An elevated concentration of methyl-tertiary-butyl-ether (MTBE) was detected in soil sample SE-8 <br /> which was collected from the former UST excavation at a depth of 19 fbg The MTBE <br /> concentration in this sample was 1,800 ppm TPPH and benzene, toluene, ethylbenzene, and <br /> xylenes (BTEX) concentrations were below or near detection limits in the soil samples collected <br /> from the former UST excavation <br /> Additional investigation performed during October 1997 included drilling two soil borings with <br /> Geoprobe equipment to determine the vertical extent of petroleum hydrocarbons and MTBE <br /> previously identified during tank removal activities Soil boring SB-1 delineated the vertical extent <br /> of the petroleum hydrocarbons and MTBE in the northwest corner of the former tank complex Soil <br /> boring SB-2 was drilled to the depth of 35 5 fbg where drilling refusal was encountered The final soil <br /> sample collected at 35 5 fbg contained TPPH at a concentration of 5,700 ppm and did not contain <br /> benzene or MTBE <br /> INVESTIGATION RESULTS <br /> jSoil Borings <br /> Personnel Present Geologist Joe Neely and Mike Murphy directed drilling activities, <br /> working under the supervision of California Registered Professional <br /> Engineer Diane Lundquist <br /> Permit A boring permit was obtained from the SJCPHS <br /> Drilling Company Gregg Drilling (C57 485165) <br /> Drilling Date April 24, 29 and 30, 1998 <br /> Drilling Methods Hollow Stem Auger <br /> Sampling Methods- Soil Irthology was logged using the Unified Soil Classification System <br /> and the Munsell Color chart Encountered lithology is described on <br /> the exploratory boring logs presented to Appendix A Soil samples <br /> were collected from the borings for hthologic description, potential <br /> chemical analysis, and head-space analysis Soil samples from the <br /> borings were screened for the presence of organic vapors using a <br /> organic vapor meter (OVM) OVM readings are recorded on the <br /> boring logs presented in Appendix A <br /> 0 <br /> 240-0797 2 <br />