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PRELIMINARY REPORT AND TANK Cr_OSURE REPORT Tracy Boulevard Shell 3725 Tracy Boulevard,Tracy.California Di-Ata Project No.40-89-012 Page 10 t "very dirty"pile. Four'soil samples were collected from each 50 cubic yards of soil stockpiled in the"dirty" or"very dirty"piles,composited and analyzed by a state-certified analytic:,,.aboratory for concentrations of BTEX and TPH as gasoline using EPA and California Department of Health Services (DHS)approved methods. Fallowing the mmoval of the underground gasoline storage tanks, soil samples were collected from the sidewalls of the excavation adjacent to both ends of each tank at .he softround water interface. The samples were collected from 2 feet into the finished excavated surfaces of the sidewalls following the methods recommended on page 13 of the Regional Board Staff Recommendations for Initial Evaluation and Investigation of Underground Tanks. Also, one soil sample was collected from every 20 linear feet of excavated product distribution line. These samples were collected from 1 foot below the bottom of the former prodder Iine trenches. In addition,soil samples were collected from the sidewalls of the excavation for the new underground storage tanks. Finally,soil samples were collected from the base and sidewalls of an excavation near the former pump islands following removal of soil containing petroleum hydrocarbons. After the former underground storage tanks were removed,a ground water sample was collected from the excavation. A visual observation of the ground water standing in the excavation did not indicate the presence of petroleum hydrocarbons. 4.1 1)escr1R[a,n or the Tank Removal Process Fillner Construction,Inc.,directed the excavation and removal of three underground gasoline storage tanks on May 3 and 4,1990(Figure 2). The tanks were purged to reduce the risk of explosion during removal and transport. Mr. William Snavely of the San Joaquin County Public Health Services,Environmental Health Division inspected each tank for holes,and verified the tanks were intact. However,the excavator used to lift the tanks out of the excavation was unable to do so until the water within the space between the inner and outer walls was drained. Therefore,holes were made in the outer walls of each tank to drain the water within the space between the outer and inner walls. This water was drained into the tank exca-ation. Samples of water from two of the three tanks (T-6 and T-7,Table 7)were collected. camp a rom tnc ank. third tank(;-5,Table 7)was not collected. Care:vas taken to avoid puncturing the inner wall of each t