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1 3.6 Laboratory Analysis of Soil and Water Samples <br /> 4 <br /> Selected soil samples were analyzed for total petroleum hydrocarbons (TPH as gasoline) and <br /> volatile aromatics(BTE&X)in accordance with EPA methods 8015m and 8020, respectively. <br /> Each water sample was analyzed for TPH as gasoline and BTE&X in accordance with EPA <br /> methods 8015m and 602, respectively. <br /> � i <br /> 4.0 FINDINGS <br /> 4.1 Stratigraphy <br /> In boring B-1, fine- to coarse-grained sands (backfill material) were encountered from <br /> surface grade to depths of 15 feet. Medium- to fine-grained silty sands were encountered <br /> from depths of 15 to 28 feet. Well sorted, medium-grained sands were encountered at <br /> depths of 28 to 38 feet. Water was encountered in the boring at a depth of approximately <br /> 36 feet. <br /> Strong hydrocarbon odors were noted in samples from depths of 15 to 35 feet. Organic <br /> vapors were detected in samples from B-1, using a PID, at concentrations as great as 2,392 <br /> ppmv. <br /> In MW-1, MW-2 and MW-3, a black adobe clay was present from near surface grade to a <br /> depth of approximately 5 feet. Alternating layers of silts and sands were present from depths <br /> of 5 feet to 30 feet; sands were encountered from a depth of about 30 to 40 feet. <br /> Alternating layers of gray to brown silt and silty fine-grained sand were present from depths <br /> of about 40 feet to the bottom of each boring. <br /> Organic vapors were detected in boring MW-2 at concentrations up to 24 ppm and in boring <br /> MW-3 at concentrations up to 307 ppm. No organic vapors were detected in MW-1. Boring <br /> logs are included in Appendix A. <br /> i <br /> 4.2 Analytical Results of Soil Samples <br /> Four soil samples from boring B-1 were analyzed by MAI. TPH as gasoline was detected <br /> in each sample at concentrations from 20 ppm (B1-25) to 3,200 ppm (131-30). BTE&X were <br /> detected in each sample at concentrations as great as 430 ppm (xylenes, BI-30). <br /> TPH as gasoline and BTE&X were detected in three samples from MW-3; toluene was <br /> detected in one sample from MW-2; and xylenes were detected in three samples from MW- <br /> 2. No petroleum hydrocarbons were detected in samples from MW-1. The analytical results <br /> are summarized in Table 2. The laboratory reports and chain-of-custody are included in <br /> Appendix C. <br /> i <br /> PJUom FIER UkUp 1954 <br /> f <br /> I, <br />