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• Mr. Ron Rowe February 24, 1999 Page 4 of 6 grained soil with silt and clay from approximately 66 to 75 feet bgs, the_maximum depth explored Groundwater was encountered at a depth of approximately 5 et_bgj Soil boring locations are shown on Figure 3 Soil boring logs are included in Attachment B Confirmation Sampling Interpretations of soil type were confirmed through traditional soil logging techniques using ASTM protocol Soil samples were collected from three borings (SBI, SB2, and SB3) at significant changes in lithology, based upon the CPT data collected from the pilot borings Borings SBI and SB2 were advanced in the vicinity of the former USTs and boring SB3 was advanced in the vicinity of the former dispenser island Samples were collected in SBI at 20 feet bgs, from SB2 at 25, 30 5, 39, 54, 65, and 72 2 feet bgs, and from SB3 at 16, 26, and 40 feet bgs No samples were collected deeper than 40 feet bgs from SB3 due to the absence of field evidence of contamination in shallow samples Samples were collected into brass tubes and each sample was screened for the presence of petroleum hydrocarbons using a flame ionization detector (FID) FID readings were recorded on soil boring logs Samples were immediately placed in a cooled ice chest Ag roundwater sample was collected from bona SB ` t 2 an approximate depth of 65 feet using a • Hydropunch sampling tool The sample was collected into pre-cooled 40 mL vials with hydrochloric acid preservative and placed in a cooled ice chest A laboratory representative transported soil and water samples under chain of custody to BSK Laboratory in Fresno, CA (FLAP #1180) All downhole drilling and sampling equipment was decontaminated by steam cleaning and/or washing with laboratory-grade detergent Decontamination water was placed into properly labeled 55 gallon drums and stored on site pending disposal No soil cuttings were generated during the sampling process LABORATORY ANALYSIS Soil samples collected from borings SBI, SB2, and S133 were analyzed for TPHg, BTEX, and gasoline oxygenate fuel additives utilizing EPA methods 8015, 8020 modified, and 8260 modified, respectively No TPHg or BTEX were detected in the sample collected from SBI at 20 feet bgs, from the sample collected from SB2 at 30 5 feet bgs, or from any sample collected from boring SB3 Petroleum hydrocarbon constituents were detected at relatively low levels in samples collected from SB2 between 30 5 and 72 2 feet bgs Benzene ranged from 0 0060 parts per million (ppm) (SB2-30 5' and SB2-65') to 0 33 ppm (SB2-72 2'), and TPHG ranged from <1 0 ppm (SB2-30 5') to 33 ppm (SB2-72 2') Methyl tert-butyl ether (MTBE) was detected in each soil sample (ranging from 0 22 ppm to 2 5 ppm) with the exception of the sample collected at 72 2 feet bgs from S132 Tert-butyl alcohol (TBA) was detected in each soil sample (ranging from 0 28 ppm to 1 8 ppm) with the exception of the samples collected from S133 at 16 feet bgs groundzeltuleburonitrpt doc