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zNNW A"grab" groundwater sample was also collected from boring SBI. To collect the water sample, a core sampler was driven to the desired depth and the screen was exposed to the bed within the formation. A 0.17 inch diameter PTFE tube equipped with a stainless steel check valve was then inserted into the rods to the bottom of the sampler. Several attempts to collect a water sample by creating a positive displacement effect within the tubing were unsuccessful due to the presence of suspended silt in the water. To enable collection of a groundwater sample, a small diameter PVC casing with a 5-foot screened interval was inserted to the bottom of the boring. Groundwater samples were collected through the casing using the PTFE tubing. Samples were immediately placed into appropriate glass containers, labeled, and placed into a cooled ice chest. The completed borings were backfilled to the ground surface with neat cement grout. No soil cuttings were generated. All down-hole drilling and sampling equipment was decontaminated by washing with a laboratory grade detergent and rinsing with water. Rinseate collected 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. 4.0 RESULTS OF INVESTIGATION 4.1 Subsurface Conditions A non native layer of A/B type baserock approximately 3 inches thick overlies native bedding, which consists primarily of lean clay and silts to a depth of approximately 22 feet bgs, the maximum depth explored. Shallow soil in the vicinity of boring SBI tended to have a higher sand content than the perimeter borings. SB 1 contained lean clay/silt with 25% sand from the ground surface to approximately 10 feet bgs, poorly graded sand with clay from approximately 10 feet to 15 feet bgs, and silt and lean clay below 15 feet. Borings SB2 and SB3 contained lean clay and silt with <5% sand from the ground surface to sixteen feet bgs. Groundwater was initially encountered at approximately 10 feet bgs in each boring and subsequently rose to approximately 7 feet bgs. No petroleum odors or discoloration were noted in samples collected from any borings. FID readings from the samples ranged from concentrations of I to 10 parts per million (ppm). Soil boring logs are included in Attachment A. 4.2 Laboratory Analysis Soil and groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethylbenzene and xylenes (BTEX), and organic lead using EPA methods 8015 modified, 8020, and the LUFT method respectively. In addition, the soil sample collected at 10 feet bgs from SBI and the groundwater sample were also analyzed for gasoline oxygenate additives using EPA method 8260. 4.3 Soil Analytical Results datalgroundze\baley\summary.doc 3