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sf . Soil Excavation Report ] B Terminal/Blmcoe Trucking 6700 Grandine Road, Tracy, CA Project No W0322 01 Page 3 Monitoring well MW 1 was destroyed under permit from San Joaquin County Public Health Services, Environmental Health Division, during excavation of the former tank area Because MW4 is directly downgradient of the former tank area MW 1 will not be replaced Soil samples were transported under chain-of-custody to the laboratory for analysis for benzene, toluene, ethylbenzene, xylenes (BTEX), and total petroleum hydrocarbons as gasoline (TPHG) by EPA methods 8020 and 8015 respectively Soil sample collection and transport was performed in accordance with RESNA's Quality Assurance/Quality Control Plan (Problem Assessment Report, April 22, 1992) Attachment 2 contains analytical data sheets and chain of custody documentation Stockpiled soil samples were collected and analyzed for BTEX & TPHG by methods 8020 and 8015, respectfully One 4 sleeve composite sample was collected per 100 cubic yards of stockpiled soil (Figure 2) RESULTS OF THE INVESTIGATION On March 11, 12, 15, and 16, 1993, approximately 200 cubic yards of soil was excavated from the former tank area Clean overburden soils, 8-10 feet thick were excavated and stockpiled separately on site The petroleum impacted soils were confined to a narrow band that ranged from approximately one foot thick south of the former tank location to nearly 3 feet thick in the immediate vicinity of the former tank area and to the north of the tank area Soils were dark gray-brown elastic silt from surface grade to a depth of approximately 5 feet, medium yellow-brown silt with sand from 5 feet to between 8 and 10 feet below grade From 8 to 10 feet to approximately 12 5 feet the contaminated silts were gray-green in color with a strong odor An OVM 580B photolonization detector (PID) was used to screen the soils for organic vapor concentrations Excavation proceeded until no remaining contaminated soil was in evidence, at which point confirmation samples were collected Laboratory Analysis - Soils Confirmation samples were collected from the capillary fringe (10'7" to 10'10" below surface grade) Figure 2 depicts both the excavation and soil pile sample locations No petroleum hydrocarbon analytes were present above method detection limits in the confirmation soil samples collected from the sidewalls Additionally no petroleum hydrocarbons were detected in the composite samples collected March 16 from soil pile SP1, the "clean" overburden soils or soil pile SP2, the "dirty" soils On April 2, 1993 an additional sample was composited from the hottest areas of the "dirty" soil pile (SP2) Analytical results indicate that TPHG (160 ppm), . benzene (0 33 ppm), toluene (0 44 ppm), ethylbenzene (1 3 ppm), and xylenes (0 59 ppm) were present in the "hottest" areas of soil pile SP2 R-32693 FNL