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Mr. Dan Barber Project 0F90-002.02 October 28, 1992 Page 3 Confirmation Soil Sample Collection and Analysis ' Confirmationsamples soil les were collected from the bottom and corners of the p excavation at depths between 9.5 and 11 feet (see Figure 2). Soil sampling procedures are presented in Appendix A. Selected soil samples were collected and screened in the field using a Hanby field test kit to assist in choosing confirmation soil samples for analysis. Samples from the bottom of the excavation and the northwest and southwest corners of the excavation were screened for petroleum hydrocarbons using the Hanby field test kit. The field screening results indicated that no detectable petroleum hydrocarbons were present in the three screened soil samples. Since the soil appeared clean, the remaining two soil samples, those from the southeast and northeast corners of the excavation, were not screened in the field. A soil sample was also collected of the gray-stained clay just below the asphalt. This sample was designated North 0.8'. ' Confirmation Soil Sample Analytical Results Each confirmation soil sample, including sample North 0.8', was analyzed for TPHD. The analytical results are presented in Table 1 , and the certified analytical reports are presented in Appendix B. The samples collected from the bottom and the southwest corner of the excavation contained petroleum hydrocarbons at concentrations of 14 and 2.2 mg/kg, respectively. These concentrations were reported as TPHD; however, the petroleum hydrocarbon in the samples was reported by the laboratory to be a higher boiling point hydrocarbon mixture rather than diesel. The samples collected from the northwest, northeast, and southeast corners of the excavation did not contain detectable concentrations of TPHD. ' Sample North 0.8' contained 34,000 mg/kg of petroleum hydrocarbons. This concentration was reported as TPHD; however, the petroleum hydrocarbon in the sample was reported by the laboratory to be a lower and higher boiling point hydrocarbon mixture rather than diesel. ' EXCAVATED SOIL Approximately 50 cubic yards of soil were generated during the excavation activities. This soil was stockpiled adjacent to the excavation during the field activities. Since the ' soil was apparently unimpacted with petroleum hydrocarbons, it was placed back in the excavation following the collection of the confirmation soil samples. Prior to the replacement of the soil into the excavation, soil samples were collected from the stockpile for chemical analysis by a state-certified laboratory. EMCON Associates collected four samples from the stockpile, and these samples were to be composited into one sample for chemical analysis. Soil sampling procedures are presented in Appendix A. py010f9010f900020 .2aw