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r <br /> FLUOR DANIEL GTI <br /> collected ranged from below laboratory reporting limits to 17 mg/kg in sample T2-S-15. A copy of the <br /> analytical report with chain-of-custody is included as Attachment 6. <br /> EXCAVATION <br /> On September 19 through 24, 1996,the tank pit was extended approximately 20 feet to the south and <br /> excavated to a depth of 13 feet BGS to accommodate the installation of three new 10,000-gallon USTs <br /> (Figure 3). Soils encountered during the tank removal included fine sand to silty sand to a depth of <br /> approximately 10 feet BGS followed by silt,silty clay, and clayey silt with some interbedded fine sand to a <br /> depth of 15 feet BGS. Soil encountered at 15 feet BGS appeared very moist to wet but no visual <br /> accumulation of groundwater was observed in the tank pit excavation or at the sample locations. <br /> Excavation Sampling <br /> On September 20, 1996, a total of seven soil samples were collected from the floor of the additional tank <br /> pit excavation:six samples at 13 feet BGS and one sample at 15 feet BGS (Figure 2). Soil samples were <br /> collected using the same protocol and analyzed for the same parameters as the samples collected <br /> beneath the USTs. The samples were transported under chain-of-custody manifest to WEST in Davis, <br /> California for analysis. <br /> Excavation Soil Analytical Results <br /> Table 1 summarizes the analytical results of the soil samples collected from the additional excavation. <br /> The samples were collected from the floor of the excavation at depths ranging from 13 feet to 15 feet BGS. <br /> Benzene was detected in only one sample, E2-W-13, at a concentration of 0.013 mg/kg. TPH-G was <br /> detected only in sample E2-E-13 at a concentration of 61 mg/kg. MTBE was not detected in any of the <br /> seven samples collected. Total lead concentrations ranged from below method detection limit to 13 mg/kg <br /> in sample E1-E-13. A copy of the laboratory analytical report with chain of custody manifests is included as <br /> Attachment 6. <br /> Soil Stockpile Sampling,Analytical Results,and Removal <br /> On September 19, 1996, eight soil samples (SP-1 through SP-8)were collected from the approximately <br /> 250 cubic yards of soil generated from the tank excavation and stockpiled on site. On September 20, 1996, <br /> four soil samples (SP-9A through SP-9D)were collected from 150 cubic yards of hydrocarbon-impacted <br /> soil generated from the additional tank pit excavation (Figure 2). In addition,four soil samples (C-1 through <br /> C-4)were collected from the approximately 265 cubic yards of clean overburden generated during the <br /> additional excavation. Sampling of the clean overburden soil took place while the soil was being removed <br /> from the site. No sample location map was generated for the clean overburden soil. Samples were <br /> collected in 6-inch brass sleeves approximately 1 foot beneath the surface of the soil stockpile. The <br /> 0384usthr(Sthl-55) <br /> Underground Storage Tank Removal Summary October 16, 1996 <br /> The Southland Corporation, 1399 North Main Street,Manteca,CA 3 <br />