ARCHIVED REPORTS_XR0012638 - Laserfiche WebLink

Home Browse Search

i ..:_, .a PRELIMINARY RFt'ORT AIM TANK CLOSURF REPORT Tracy lloulcvartt Shell 3725 Tracy Boulevard,Tracy,Cali(omrn a Delta Project No.4U-89-012 Page 12 IPH concentrations were detected in the sample from the west end of the unleaded premium tank(71V)at 0.1 and 3.3 ppm,respectively. Verbal communications with the laboratory indicated that this sample(7w) may contain Stoddard solvent. Xylenes,ethylbenzene,and TPH concentrations were detected in the sample from the east end of the unleaded premium tank(7E)at 2.0,0.9,and 46.0 ppm,respectively. 4.4 Soil Condltlons Beneath the Former Pmdnct Lines On May 4,1990,following the removal of the underground gasoline product lines between the storage tanks and the former pump islands,a Delta geologist collected three soil samples from 1 foot below the bottom of the excavated product line trenches. Soil sample locations are presented in Figure S. The samples were shipped to a state-certified analytical laboratory and analyzed for BTEX,TPH as gasoline,organic lead,and EDB. Table 8 presents the Iaboratory analytical results, and Appendix H presents the laboratory data sheets. The r--ults indicate that BTEX concentrations were below analytical method detection limits and TPH concentrations in soil samples lil and L-2 were 0.06 and 0.19 ppm,respectively. Concentrations of xylenes, ethylbenzene,and T PH in soil sample Ir3 were 0.6,0.5,and 25.0,respectively. Concentrations of organic _ lead and EDB were below detection limits in all three samples. 4.5 Soil Conditions in the New Tank Excavation v On May 18, 1990, following the placement of sheet piling around the perimeter of the new underground gasoline storage tanks location,a Delta geologist collected soil samples from the outer perimeter of the new excavation.. The samples where collected with a backhoe at the soil/ground water interface at 8 to 9 feet below the ground surface. Sample lo:—tions are shown in Figure 8. The samples were shipped to a state-certified analytical laboratory and analyzed for BTEX. TPH as gasoline,organic icad, and EDB. Table 9 p,csents the Iaboratory analyses results,and Appendix H presents the laboratory data sheets. 4.6 Soil Conuitions Beneath the Flow-Throukh_Tank On May 31, 1990,during station reconstruction activities,a flow-through tank was discovered. The tank rneasur eet wide, I6.5 feet long,and 4 feet deep,and was buried 2 feet deep. The tank was constructed. w of concrete and contained two compartments, an inflow pipe, and an outflow pipe. The outflow pipe discharged directly to the soil;no leach lines were present.