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SECTIONTW® Summary of Field Sampling and Laboratory Analyses 2.1 SUMMARY OF FIELD INVESTIGATION ACTIVITIES On-site drilling activities were performed on August 2-3, 1999, supervised by Mr Richard Ely, R G , Project Geologist of URSGWC A total of five soil borings were drilled at the site in the vicinity of the former underground storage tank (see boring logs provided in Appendix A) The locations of borings are shown on Figure 1 The samples were obtained using a 2t/4-inch diameter direct-push sampler that was advanced into the ground using a track-mounted Geoprobe device The soil samples were collected from within the sampler by removing a stainless-steel sample liner and capping each end with aluminum foil and plastic endcaps Sampling equipment and augers were cleaned by pressure washing between sampling events A groundwater sample was collected from Boring B-1 following the installation of a temporary PVC well of 3/4-inch diameter The groundwater sample was collected using a clean stainless steel bailer The groundwater sample and the soil samples were sealed, individually labeled and stored on ice in an ice chest prior to transportation to Chromalab Analytical Laboratory, Pleasanton Chain- of-custody procedures were used during sampling and transport of these samples Drill cuttings from the soil borings were collected and stored on-site in 55-gallon drums The drums were appropriately labeled and sealed for later disposal 21 1 Observations of Subsurface Conditions 1 Boring B-1 was drilled through the former diesel-UST location Boring B-4 was drilled through the former gasoline-UST location Borings B-2, B-3 and B-5 were located to the north and west of the former UST locations (Figure 1) Subsurface native soils were predominantly silt, sandy silt, and silty very-fine-grained sand (see the boring logs in Appendix A) Permeable sand beds were sampled at 40-ft and 55-ft bgs in Boring B-1, at 25- to 30-ft bgs in Boring B-3, and at 15- to 20-ft bgs in Boring B-5 These beds contained few fines and consisted mostly of medium- to coarse-grained sand The sand bed at 40-ft bgs in Boring B-1 was medium- to very coarse-grained, contained few fines, and was water saturated Groundwater sample BA W was collected from this unit 2.2 ANALYTICAL RESULTS Soil and groundwater samples were analyzed by Chromalab, Inc of Pleasanton, California for BTEX, MTBE, TPH-gasoline, and TPH-diesel by EPA Methods 8020 and 8015M 2.2.1 Soil Analytical Results rTable 2-1 presents the results of the laboratory analyses performed on the soil samples from the . site Results above the detection limit are bolded MTBE, benzene, and xylenes were not detected in any soil sample URS Greiner Woodward Clyde 11099670491UST REPORT CHEROKEE DOCti22 SEP 99MAK 2-1