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Woodward-Clyde `'V Consultants Diane M. Hinson San Joaquin County Environmental Division October 11, 1994 Page 3 from the bottom of the excavation below each tank end. Soil samples were collected by scraping away 1 to 2 feet in the area of the backhoe teeth, at a chosen "most representative" sample point. Samples were collected by pushing a clean brass liner into the sample point area until full, then placing a Teflon sheeting and plastic endcap over each end, labeling it with sample number, time and date, then placing on blue ice in an ice chest until the samples could be transported under chain of custody procedures to a California certified analytical laboratory. Four soil samples (TK1-1, TK1-2, TK2-1, and TK2-2) were analyzed for Total Petroleum Hydrocarbons (TPH) as diesel and as gasoline using modified EPA Method 8015 and benzene, toluene, ethylbenzene, and xylenes (BTEX) using EPA Method 8020. A summary table of analytical results of the four soil samples is presented in Table 1. Sample locations are shown in Figure 3. Soil sample TK1-1 was collected beneath the north end of the former location of Tank #1 at a depth of 22 feet bgs and consisted of a mottled greenish gray silty clay material with slight petroleum-like odor. Sample TK1-1 contained non-detectable concentrations of TPH as gasoline, benzene, toluene, and ethylbenzene, and detectable concentrations of 0.240 mg/Kg (parts per million-ppm)xylenes, and 3600 mg/Kg TPH as diesel. Soil sample TK1-2 was collected from beneath the south end of the former location of Tank #1 at a depth of 17 feet bgs, and consisted of a light yellowish brown clayey silt material with no observed odors. Sample TK1-2 contained non-detectable concentrations of TPH as gasoline and diesel, and BTEX. Soil sample TK2-1 was collected from beneath the north end of the former location of Tank #2 at a depth of 16 feet bgs, and consisted of a light yellowish brown clayey silt material with no observed odors. Sample TK2-1 contained non-detectable concentrations of TPH as gasoline and diesel, and BTEX. Soil sample TK2-2 was collected from beneath the south end of the former location of Tank #2 at a depth of 22 feet bgs, and consisted of a dark greenish-gray silty clay material with no observed odors. Sample TK2-2 contained non- detectable concentrations of all analytes tested. The analytical laboratory reports are attached for reference. Based on the analytical laboratory results of the four soil samples collected below the USTs an area of diesel contaminated soil still remains at the bottom of the tank excavation in the former location of the north end of Tank #1 (Figure 3). The width and length of diesel contaminated soil was observed to be approximately 12-feet by 15-feet respectively near the center of the tank excavation. 4Pb4055W\YFs.WP(10-10-94)SAC Gari>,