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�- Underground Tank Sites". Soil samples E-1-10 and E-2-10, from the excavation, were collected at approximately 10 feet below ground surface (bgs). The soil samples were collected by driving a pre-cleaned brass tube into relatively undisturbed soil that had been removed by the excavator. Figure 3 shows the excavation soil sampling locations as well as the location of the two composited samples (C-1, C-2, C-3) and (C-4, C-5) collected from the stockpile. The soil samples were analyzed for total petroleum hydrocarbons as diesel (TPH-D) by EPA Method 8015M; and benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA Method 8020. All soil samples were analyzed by WEST Laboratories mobile laboratory, California State Certification No. 1346. 2.2 Laboratory Results A total of four soil samples was analyzed by the onsite laboratory. The onsite mobile laboratory results indicated that the soil samples collected from the excavation E-1-10 and E-2-10 did not contained TPH-D or BTEX at or above the method detection limit. However, composite samples obtained from the stockpiles of excavated soil did report the presence of petroleum hydrocarbons. Composite sample C-1, C-2, C-3 contained TPH-D at a ` concentration of 10 milligrams per kilogram (mg/kg). Composite sample C-1, C-2, C-3 did not contained BTEX at or above the relevant methods reporting limit. Composite sample C-4, C-5 contained TPH-D at 120 mg/kg and toluene, ethylbenzene, and total xylenes at 0.0073 mg/kg, 0.028 mg/kg and 0.16 mg/kg respectively. Based upon laboratory results, SJCDEH would not permit the return of the stockpile soils to the excavation. On November 16, 1994, the excavation was backfilled with imported material. The 41-cubic yard stockpile was unlain and covered with Visqueen sheeting in the northern comer of the parking lot until its removal. Appendix B contains the complete analytical report, with chain of custody records. Upon receipt of the analytical results from E-1-10 and E-2-10, imported material was placed into the excavation and compacted by Brandon construction. �' 3