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c- <br /> 1 <br /> ww <br /> NNA <br /> 1:w9 <br /> 5 ANALYTICAL, RESULTS AND DISCUSSION <br /> s.1 Soil Samples <br /> Soil samples initially collected from each of the sail borings were evaluated for total <br /> Ci <br /> petroleum hydrocarbon compounds, and purgeable halocarbons. In addition, the soil <br /> samples collected from the angle borings under the 500 gallon leaded gasoline tank were <br /> evaluated for 1,2 EDB and TEL. The laboratory results are summarized and presented <br /> in Table 1. Complete analytical reports were presented in the PAR. <br /> } The analytical results show that none of the soil samples collected from the borings contain <br /> detectable levels of petroleum products or purgeable halocarbon compounds. As a result <br /> the borings define a clean zone a-ound the former underground waste oil tank• Only <br /> SB-1, located adjacent to the sere`.c garage, contained any visible trace of contamination. <br /> The location of SB-1 therefore, represented a southward limit of the extent of waste oil <br /> contamination remaining in the soil following the Problem Assessment Investigation. Since <br /> previous sampling of the former waste oil tank excavation had confirmed the removal of <br /> all contaminated soil in the north, east and west walls of excavation, (Tank Excavation <br /> �< Assessment Report, February 1990) SB-1 provided an estimate of the areal and vertical <br /> i <br /> extent of the remaining contamination. <br /> Following the submittal of the PAR, Murray & Associates re-excavated the soil in the <br /> immediate vicinity of SB-1 and removed the majority of the contaminated soil left after the <br /> initial excavation activities. Although minor amounts of waste oil residue may still remain <br /> 1 M in the soil immediately adjacent to the bervice garage, the material has now mineralized <br /> and no longer represents a potential threat to groundwater quality• <br /> Soil samples collected from beneath the 500 gallon leaded gasoline tank also shows no <br /> --- — -— - -- --—detectable-levels-far-gasoline,_Vi'XE,-EDB_and TEL, suggesting-that no leakage had — <br /> occVrred from either the tank or its associated pipelines. <br /> 9 <br />