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Project No. JB-20100 4 December 2000 Page 2 This study does not include an environmental assessment or investigation for the presence or absence of hazardous or toxic material in structures, soil, surface water, groundwater, or air on, below or around the project site. 2.0 SITE EXPLORATION AND LABORATORY TESTING 2.1 Site Exploration The subsurface conditions of the site were explored on 15 November 2000. The exploration consisted of drilling five exploratory borings to a maximum depth of about 261.12 feet below the existing site grade. Boring B-5 was drilled next to Boring B-1 at the request of Chevron to further determine groundwater depth. All boring locations drilled at the project site are shown in Figure 2, Boring Location Map. The borings were drilled using a truck- mounted, CME 75 drilling rig. Soil encountered during drilling were logged and samples were obtained to • aid in material classification and for laboratory testing. Soil samples were recovered in either a 3-inch or 2.5-inch outside diameter (OD) California sampler or a Standard Penetration Sampler driven by a 140-pound hammer free-falling 30 inches. The number of blows applied to advance the sampler was recorded for each 6 inches of penetration. Blow counts from the bottom 12 inches of penetration were recorded on the logs as blows per foot and recorded on the boring logs. Figure 3, Boring Log Legend, illustrates the Unified Soil Classification System which was used to identify subsurface soil during drilling. The logs describing the material encountered in the borings were recorded in the field by our representative and are shown on Figures 4 through 8. 2.2 Laboratory Testing Laboratory testing was conducted on selected borehole samples to obtain data on density, moisture content, and classification of the soil. Test results are shown on the Boring Logs. Sieve analyses (#200 wash) were performed on selected soil samples of the subgrade soils. The tests were performed according to American Society of Testing Materials (ASTM) test methods and procedures. The test results are shown on the Boring Logs. MKorbmacher Engineering, Inc.