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1 <br /> r{` 7 <br /> . Beacon Station No 641 August 2, 1996 <br /> 1210 East Hammer Lane Stockton Cal ifomia Letter Report <br /> exhibited no observable consequential corrosion After the removal of the USTs, soil samples <br /> were collected from the native soil located approximately 2 feet below each end of the USTs <br /> Soil samples and excavated soil removed from the cavity were evaluated in the field utilizing a <br /> photoionization detector (PID) The UST and soil sample locations are depicted on the attached <br /> Figure 2 After removal of the product lines and dispensers, soil samples were collected from the <br /> native soil in the product line trench and beneath the former dispenser locations at a depth of <br /> approximately 2 to 3 feet below the base of the trenches (see Figure 2) The soil samples were <br /> submitted to a state-certified laboratory for analyses with results to be reported the following <br /> morning <br /> On June 12, based on laboratory results from the previous day, additional samples were collected <br /> from test holes bored 18 to 19 feet bsg on the western and eastern portion of T1, and the western <br /> portion of T2 Locations of theses samples are depicted on Figure 2 The dispenser area and <br /> product line trench was excavated to approximately one foot below the depth of previously <br /> collected samples or approximately 4 to 5 feet bsg The PID indicated that gasoline <br /> hydrocarbons were present in the soil excavated from the test holes Additional excavation was <br /> halted and the samples collected from the test pits were submitted to the laboratory Harlin Knoll <br /> was onsite to observe collection of the additional samples The UST cavity was excavated to <br />• approximately 18-19 feet in its western side to allow for installation of the new USTs The <br /> completed extent of the excavation is shown Figure 2 <br /> Analytical Results <br /> Selected soil samples collected from the UST cavity excavations, and product lines and dispenser <br /> excavations were submitted under chain of custody (COC) to West Analytical Laboratory in <br /> Davis, California (Certification No 1346) The samples were analyzed for Total Petroleum <br /> Hydrocarbons as gasoline (TPHg), the volatile aromatics benzene, toluene, ethylbenzene, and <br /> total xylenes (BTEX), using modified U S Environmental Protection Agency (USEPA) methods <br /> 5030/8015 and 5030//8020, respectively, lead using USEPA method ICP by SW 846 method <br /> 6010, and Methyl-tertiary-butyl ether (MTBE) using USEPA method 8020/602 In addition, the <br /> soil samples collected from the stockpile of excavated soil were composited in the laboratory and <br /> analyzed for TPHg ,BTEX, and lead <br /> Soil samples analyzed from the UST excavation ranged from below laboratory detection limits <br /> (S-14-T4w) to 6,800 milligrams per kilogram (mg/kg) (S-19-TIe) for TPHg BTEX constituents <br /> ranged from less than laboratory detection limits (S-14-T4w) to 930 mg/kg (S-19-T1e) TPHg <br /> and BTEX were below laboratory detection limits in the samples analyzed from the product line <br /> trench Gasoline hydrocarbons were detected in the soil samples collected from beneath the <br /> dispensers, ranging from below laboratory detection limits (S-D-NW, S-D-ME, and S-D-MW) to <br /> 3 6 mg/kg (S-D-SW) Total lead was detected in soil samples analyzed from the UST excavation <br /> 1641-11 rpt 2 HORIZON ENVIRONMENTAL INC <br />