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excavation Of the soil removed, 700 cubic yards were placed into "contaminated" stockpiles <br /> and 300 cubic yards were placed into "clean" stockpiles. Groundwater was encountered in <br /> the excavation at a depth of approximately 12 feet <br /> Petroleum hydrocarbons were detected in the north wall of excavation at concentrations of <br /> 350 ppm (TPH as gasoline) and 160 ppm (TPH as diesel) Petroleum hydrocarbons were <br /> also detected in the east wall of the excavation. <br /> On September 7 and 8, 1993, under the direction of the PHS/EHD, the "clean" stockpiles <br /> were used to partially backfill the excavation The soil was placed into the excavation and <br /> compacted using a loader/backhoe <br /> Sampling <br /> 2.8 Stockpilep g <br /> On September 8, 1993, 14 samples were collected from the "contaminated" stockpile and <br /> analyzed for TPH as gasoline and diesel and BTE&X The "contaminated" stockpile was <br /> then spread to allow access to monitoring well MW-1 and to facilitate future remediation <br /> Average concentrations for all petroleum hydrocarbons were very low within the stockpiled <br /> soil Six of the fourteen samples analyzed were reported as "not detected" for TPH and <br /> BTE&X Only two samples had TPH as gasoline concentrations of more than 10 ppm, and <br /> only 5 samples had diesel concentrations in excess of the detection limit (1 ppm) <br /> Gasoline was detected in sample S-11 at a concentration of 1,100 ppm, and volatile <br /> aromatics were detected in this sample at 0 35 ppm (xylenes) <br /> 3.0 PROCEDURES <br /> 3.1 Excavation Backfill <br /> On December 31, 1993, the excavation was backfilled to surface grade Pea gravel was <br /> imported and used as fill material Backfilling of the excavation was performed by Stokley <br /> Construction of Tracy, California <br /> 3.2 Soil p p Stockpile Disposal <br /> On December 13 and 20, 1993 and February 3, 1994, the stockpiled soil was transported to <br /> Forward Inc , in Stockton, California, a licensed landfill facility Approximately 670 of the <br /> 700 cubic yards of stockpiled soil were transported by Manley and Sons Trucking, Inc under <br /> t non-hazardous manifest. <br /> Two samples were collected from the remaining soil stockpiled on-site (approximately 30 <br /> cubic yards Soil samples were collected in clean, 2 by 3-inch brass tubes The ends of the <br /> tubes were covered with aluminum sheets, capped and sealed with tape <br /> I Grob�al A*49 Semcxi,lam L <br /> Sxww Ham QR9N-94tl61 i 5 <br />