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• When the tool was advanced to the desired depth, extension rods were sent downhole to brace <br /> the bottom of the sample screen as the tool casing was retracted When the casing was retracted, <br /> approximately 41-inches of screen with slot sizes of 0 004 inches was exposed Teflon tubing <br /> with a check valve attached to one end was inserted down the casing until it was immersed in <br /> groundwater Water was then pumped through the tubing and to the ground surface by <br /> oscillating the tubing up and down Groundwater samples were placed on ice and delivered under <br /> chain-of-custody documentation to AEN for chemical analysis Following soil and groundwater <br /> sample collection, the borings were backfilled with neat cement grout to the ground surface <br /> Soil and Groundwater Sample Analysis <br /> All soil samples were analyzed by AEN for total petroleum hydrocarbons as gasoline, (TPHg) by <br /> EPA method 8015 modified, benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA <br /> method 8020, oxygenate fuel additives by EPA method 8260, and total lead In addition, soil <br /> samples from borings SBI and SB2 were analyzed for total petroleum hydrocarbons as diesel <br /> (TPHd)by EPA method 8015 modified <br /> All groundwater samples were analyzed for TPHg, BTEX, and oxygenate fuel additives In <br /> addition, groundwater samples from borings SB2, SB4, SB5, and SB6 were analyzed for TPHd <br /> and total lead <br /> • RESULTS OF INVESTIGATION <br /> Site Geology <br /> Backfill was encountered in soil boring SBI in the upper 14 feet of the soil column Soil from <br /> depths between 14 feet bgs and 16 to 19 feet bgs consisted of silt Soil from depths between 16 <br /> to 19 feet bgs to 21 to 24 feet bgs consisted of poorly graded sand with silt Soil from depths <br /> between 21 to 24 feet bgs and 25 5 feet bgs consisted of elastic silt with sand Below 25 5 feet <br /> bgs, poorly graded gravel and sand were encountered to a depth of 31 feet bgs, the maximum <br /> depth explored Soil encountered in boring SB2 from 14 to 16 feet bgs consisted of silty sand <br /> The remainder of the borehole was not logged Soil encountered in boring SB7 from the surface <br /> to 6 to 9 feet bgs consisted of poorly graded sand with silt Below 6 to 9 feet bgs, lean clay was <br /> encountered to a depth of 26 feet bgs, the maximum depth explored <br /> Soil Analytical Results <br /> Soil samples collected from borings SB 1 and SB2 in the vicinity of the former UST on the <br /> southern part of the site contained elevated concentrations of TPHd and relatively moderate <br /> concentrations of TPHg Concentrations attenuate rapidly below 20 feet bgs, the depth at which <br /> groundwater was encountered None of the soil samples collected from borings SBI and SB2 <br /> contained detectable concentrations of BTEX or oxygenate fuel additives Soil samples SB1-15, <br /> • SBI-25, and SB2-15 contained detectable concentrations of total lead <br /> w 1625041reports\sum doc 3 <br /> • <br /> SMTN <br />