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LA �GeolagiealTeclucics lice. Page 4 Site Characterization Report Project No. 1218.2 La February 9, 2006 LN The vials and bottle were labeled and placed on ice for shipment to the laboratory. Clean disposable gloves were worn at all times in handling of the sample and sampling equipment. 6. 2.2.2 Groundwater Laboratory Analyses The groundwater samples collected were delivered to Castle Analytical Laboratory (California ELAP No. 2480), of Atwater, California, for the following analyses: LE • Benzene, toluene,ethyl benzene and xylene (BTEX) by EPA method 8020 • Gasoline range petroleum hydrocarbons (TPH-G) by EPA method 8015 • Diesel range petroleum hydrocarbons (TEPH-D) by EPA method 8015 The detection limits for these compounds are listed in the laboratory data sheets included in Appendix B and summarized in Table 1 of Appendix A. A Chain of Custody was completed ;. for all samples collected and tracked to ensure sample integrity. �. 3.0 RESULTS OF INVESTIGATION A summary analytical data table is included in Appendix A. Laboratory Data Sheets are i. included in Appendix B and borehole logs are included in Appendix C. The geology, field observations and analytical results are discussed below. 3.1 Geology and.Field Observations The following section discusses the subjective field observations and geology documented �.. during this investigation based on the interpretations of the field geologist. The boring logs for this investigation and the original GP-1 through GP-3 boreholes are attached in Appendix C. L.• • The soils of this site are predominately clays and silts. They range from brown to olive or grey in color, little to high plasticity, dry to wet, and occasionally contained white caliche-like nodules or veins. Black mafic mineral clusters or organics were also +- occasionally present giving the soil a mottled appearance. • Minor, thin sand units were identified at depths of 5, 8, 27, 32 - 34, 50 and 58.5 feet bgs. However, the sand units are not laterally continuous across the site. '-' • OVM readings indicated minor residual soil contamination in boring SB-3 located adjacent to the UST. The OVM reading in this boring at 12 feet was 170 parts per million (PPM). The values below this point ranged 0- 1 PPM to SB-3's total depth of 60 feet bgs. • OVM readings from the other four borings SB-1, S13-2, SB-4 and SB-5 did not register above "0" PPM. • The first indication of groundwater was the wet sand identified in SB-3 at 58.5 feet bgs. When the rods were retracted the groundwater stabilized at approximately 50 feet bgs. SJC/EHD staff on site for the drilling stated that groundwater depths in the vicinity are typically deeper in the 85 -90 feet bgs range. This suggests that the water encountered in SB-3 may have been a perched aquifer level.