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Mr. Harlin Knoll October 19, 1999 Page 3 of 6 ,f SB2 and SB4, three soil samples from boring SBS, an four soil samples from boring SB3/3A were labeled, scaled, and immediately placed in an iced coo er fortransport to a state-certified analytical laboratory under chain of custody documentation. Soil samples collected from the direct push borings were selected based on observations and field screening results. "Grab" groundwater samples were also collected from borings SBI through SB5. Water samples wereh collected using 0.17 inch diameter PTFE tubing equipped -A th a stainless steel check valve lowered through a temporary PVC casing with a 5-foot screened interval. The water sample was brought to the surface b" creating a positive displacement effect within the tubing. Groundwater samples were immediately placedy into appropriate glass containers, labeled,and placed into a cooled ice chest. Hand augered borings were advanced using a 3-inch diameter stainless steel auger to the desired sampl. 9q depth. Samples were then collected into 2-inch diameter brass tubes using a hand operated percussioni hammer. Samples were immediately capped with Teflon tape and plastic caps, labeled, and placed in a'� cooled ice chest pending transportation to the laboratory. All completed borings were backfilled to the ground st rface with neat cement grout. Soil cuttings generated from the advancement of hand angered borings were placed with the existing stockpiled soil generated during the UST removal. No soil cuttings were generated from the direct push borings. All down-hole drilling and sampling equipment was decontaminated between usage by washing with a laboratory grade detergent and rinsing with water. Rinseate �rollected from decontamination procedures was disposed of via evaporation on the asphalt/concrete surface within the confines of the investigation area. Soil and groundwater samples were submitted under chain of custody protocol to Argon Laboratories for analysis. i 4.0 RESULTS OF INVESTIGATION 4.1 Subsurface Conditions E Asphaltic concrete, approximately 4 inches thick and A/B baserock fill from approximately 4 inches to approximately 1 foot bgs overlies native bedding in the hand auger boring locations. Shallow subsurface soils encountered in the hand auger borings were generally sandy silt to clay, and were similar to those .� encountered during the advancement of the direct push boring. No fill was encountered during the advancement of the direct push borings. Soil encountered during drilling consisted of interbedded clays, silts, and silty sands. The interval from the ground surface to approximately 11-14 feet bgs consisted primarily of sandy sins and clays underlain by silty clay, sandy clay, and silt with sand. Shallow soil in the south and eastern portions of the site (SB2 and SB3/3A) contains a k lower percentage of sand. Silty sand was encountered fromproximately l l-14 feet bgs to depths ranging € from 16-19 feet bgs (SB5)to 21-24 feet bgs (SB3). No siltyltnd was encountered in borings SBI or SB4, !E which were terminated at depths of 12 and 16 feet,respectively. Soil boring logs are included in Attachment :E A. Ground water was first encountered at depths ranging from approximately 4 to 10 feet bgs in borings SBI- SB4 and at approximately 14.5 feet in boring SB5. Groundwater was first encountered in hand augered borings at approximately 7.5 feet bgs. Petroleum odors were noted in samples collected from b rings SBI, SB2, and SB3, as well as hand i manserZsummary.doc k e f