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1� <br /> 4.2 Phase II Excavation <br /> The soil lithology was essentially the same in the phase 1I excavation as in the phase I excavation <br /> • with the exception of a fine sandy layer at the northern-mast corner. Pothole PH-1 was <br /> ' excavated to a total depth of 22 feet at this location and did not encounter the brown clay layer <br /> observed at all other bottom locations. <br /> A volume of 375 cubic yards of gasoline contaminated soil was removed during performance of <br /> the phase II excavation. Six sidewall samples, three bottom samples, and three pit samples were <br /> ' collected during excavation. Analytical laboratory data are presented in Table 2 below along <br /> with PTD readings obtained at each sample location. Laboratory data sheets and the chain of <br /> custody documents are included in Appendix A. <br /> ' The sidewall soil sample results indicate that gasoline and gasoline constituents remain along the <br /> northern boundary of the excavation. Sample SW-9 contained a TPH gasoline level of 2,900 <br /> mg/Kg. The remaining five sidewall samples indicated gasoline levels less than 880 mg/Kg, <br /> three of which were less than 200 mg/Kg gasoline. Benzene and toluene levels were low for all <br /> of the phase II sidewall samples including several non-detectable levels. <br /> ' The three bottom samples collected from the phase II excavation indicated non-detectable or low <br /> gasoline and BTEX concentrations. Gasoline was not detected above the laboratory detection <br /> ' level in any of the three bottom samples. Benzene was detected in one of the samples, 10-12', at <br /> l a level of 23 µg/Kg. <br /> '�. The three soil samples collected from known or suspected contaminated material contained <br /> gasoline levels ranging from 1,300 mg/Kg to 3,500 mg/Kg. <br /> 1 <br /> I <br /> American Geological Services, Inc. <br /> CA95DE-029 <br /> ' 14 <br />