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� v 0 A S S O C I A T E S I N C When the tool was advanced to the desired depth, extension rods were sent downhole to brace the bottom of the sample screen as the tool casing was retracted When the casing was retracted, approximately 41-inches of screen with slot sizes of 0 004 inches was exposed Teflon tubing with a check valve attached to one end was inserted down the casing until it was Immersed in groundwater Water was then pumped through the tubing and to the ground surface by ' oscillating the tubing up and down Groundwater samples were placed on Ice and delivered under chain-of-custody documentation to Sequoia for chemical analysis Following soil and groundwater sample collection, the borings were backfilled with neat cement grout to the ground ' surface Selected groundwater samples were analyzed by Sequoia for TPHg, TPHd, BTEX, oxygenate fuel additives, and total lead ' 3.0 SUBSURFACE CONDITIONS Soil from borings SB7 through SB 1 I consisted of poorly graded sand with silt from the surface to depths between 6 to 9 feet bgs and 1 1 to 14 feet bgs Soil from depths between 6 to 9 feet bgs and 11 to 14 feet bgs to 31 feet, the maximum depth explored, consisted of poorly graded to well graded sand Soil boring logs with a detailed description of soil types are contained In Appendix ' A 4.0 RESULTS 4.1 Petroleum Hydrocarbons in Soil Soil samples collected at depths of 20 feet bgs from borings S137, S138, SB 10, and SB 1 1 and the sample from SB10 at 25 feet contained no detectable concentrations of TPHg, BTEX, or ' oxygenate fuel additives The only soil sample collected from boring S139 contained trace amounts of xylenes, but contained no other detectable concentrations of petroleum hydrocarbons ' The soil sample collected from boring S138 at a depth of twenty-five feet bgs contained detectable concentrations of toluene, ethylbenzene, xylenes, TPHg, and TPHd, but did not contain detectable concentrations of oxygenate fuel additives The soil sample collected from boring SB 1 1 at a depth of twenty-five feet bgs contained trace amounts of benzene and TPHd, but contained no other detectable concentrations of petroleum hydrocarbons Analytical results of soil samples are summarized in Table 1 Laboratory data sheets and chain-of-custody documentation for soil ' samples is presented in Appendix B ' 4_2 Petroleum Hydrocarbons in Groundwater The grab groundwater sample collected from boring SB7 contained no detectable concentrations of TPHg and BTEX The grab groundwater sample collected from boring SB 1 1 contained TPHg ' at concentrations of 150 parts per billion (ppb), but contained no detectable concentrations of BTEX The grab groundwater sample collected from boring SB 10 contained trace amounts of benzene, xylenes, and TPHg, and contained elevated concentrations of TPHd The grab groundwater sample collected from boring SB8 contained elevated concentrations of TPHg, but w\I 3099Veports�sum2 doe 3