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Upon completion of sample collection, the samples, along with the appropriate sample chain Of custody documents, were shipped overnight to the Quality Assurance Laboratory in San Diego, California for analysis The following section provides a discussion of the sample analytical results The actual analytical report, along with the sample chain of custody documentation forms, is included in Appendix B 40 SAMPLE ANALYTICAL RESULTS Table 2 provides a tabular listing of the analytical results for the sal samples collected at the site A brief discussion of the results is contained in the following subsections 41 Total Petroleum Hydrocarbons (TPH) Of the sixteen soil samples analyzed, two exhibited detectable concentrations of TPH Sample UGS, collected from the south side of the unleaded gasoline storage tank excavation bottom (Figure 3), exhibited a TPH concentration as gasoline of 785 mg/kg Sample BSS1, collected as a composite from the small excavation overburden stockpile located west of the excavation, exhibited a TPH w concentration as diesel of 367 mg/kg 42 Benzene Toluene X lene and Eth lbenzene BTX& Of the sixteen soil samples analyzed, only one sample, DSS1 exhibited no detectable concentrations for the BTX&E compounds However, with the exception of sample UGS which contain BTX&E compound concentrations of 445 mg/kg, 1 03 mg/kg, 4 58 mg/kg and 3 77 mg/kg respectively, the BTX&E compound concentrations within the soil samples collected at the site fall well below the LUFT manual recommended maximum allowable levels of 0 3 mg/kg, 0 3 mg/kg, 1 4 mg/kg and 1 0 mg/kg for Benzene, Toluene, Xylene and Ethylbenzene respectively 43 Ethylene Dibro_mide (EDB) and Total Lead CrL) Of the sixteen samples analyzed, no EDB was detected and the TL concentrations detected are within the typical background concentration range for soils in the Stockton area 5 0 CONCLUSIONS AND RECOMMENDATIONS Based on the visual observations conducted during the tank removal program at the 4555 Pershing Avenue site and on the analytical results for the soil samples collected during the tank removal, it appears that only two areas of concern regarding petroleum hydrocarbon residues exist The first 61- area of concern is the small stockpile of overburden soil from which sample BSS1 was collected (Figure 3) The composite soil sample collected from this stockpile exhibited a TPH as diesel concentration of 367 mg/kg The second area of concern is the portion of the excavation from which soil sample UGS was collected This soil sample exhibited a TPH as gasoline concentration ✓ of 785 mg/kg TreaTek recommends that for the first area of concern, the stockpile from which soil sample BSS1 was collected, that the stockpiled soils be treated/disposed of in accordance with regulatory requirements • 6