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F\Pr0JeCU\531-WI\u9trep EPA Method 8020. The deepest soil sample from each boring also was sent to the laboratory for analysis to confirm field observations that it did not contain high levels of hydrocarbons. Ground water was not found in any of the borings. Samples obtained from the borings near the former waste oil tanks were also analyzed for Chlorinated Hydrocarbons using TEPA Method 8010 and Total Gil and Grease, using TEPA. Method 503 D&E. as per Tri-Regional dater Quality Control Board Recommendations. An additional soil sample (HA-2 was also obtained from a depth of approximately 2 feet in an area of extensive rubber shavings from tire-retreading operations. This sample was outside of the fueling area. Soil sample HA-2 was analyzed for total lead, total oil and grease, TPH as gasoline, diesel fuel, and motor oil, and BTEX. Soil boring and sampling procedures are presented in appendix A. Boring and Analyses Results t The boring logs are presented in Appendix B. The soil beneath the site generally consists of homogeneous unconsolidated alluvium, typical of the central valley. The uppermost 5 feet is generally a moderately stiff; black clay, with some product odor in samples near the product lines. Beneath this layer is a homogeneous, loose, brown silt, occasionally containing some discontinuous intervals of clayey or sandy material. This silt layer appears Jto extend to at least 50 feet, based on the deepest boring drilled on site. Table 1 presents soil sample analytical results. Soil samples from the bonngs around the tanks (B1-B6) indicate total levels of petroleum hydrocarbons in the soil of less than 100 parts per million (ppm), except for the sample from 15 feet in Boring B2, which had TPH- gasoline and diesel concentrations of 440 and 6,600 ppm, respectively. The majority of the soil containing hydrocarbons appears to be concentrated along the product lines, from Boring B6 to B9. 1,evels of TPH-gasoline and diesel were as high as 5,800 and 12,000 ppm, respectively. 'These data agree with reports of product line leaks in the past. Soil samples taken from borings near the former waste oil tanks (HA-1 and B-13) contained nondetectable levels of chlorinated hydrocarbons. Sample HA-1 contained 320 ppm total oil and grease and nondetectable levels of TPH as gasoline and BTEX. The sample contained 3 5 ppm TPH as diesel and 20 ppm TPH as motor oil. The soil sample from Boring B13 contained nondetectable levels of TPH as gasoline, diesel, and motor oil, as well as nondetectable levels of total oil and grease,benzene, and ethylbenzene. The sample contained 2.6 ppb toluene and 3.2 ppb total xylenes. These analytical results indicate that Borings HA-1 and B13 are probably outside of the area of soil containing hydrocarbons from the fueling facility. 2