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Figure 4 displays cross section views A — B (west UST); C — D (middle UST) and E — F (east UST). Using clean 8 inch hollow stem augers powered by a truck mounted drilling rig, slant borings will be drilled at each end of each tank from points A, B, C, D, E and F into native soil approximately 1 to 1.5 feet beneath each end of the three UST's. At point A the angle of the slant will be 400 from vertical, boring 24 to 25 feet which will place the sample point horizontally fifteen feet northwest of point A at a vertical depth below surface of 19 to 19.5 feet. A sample will then be obtained of relatively undisturbed native soil approximately 1 to 1.5 feet beneath the fill at the southern end of the western UST. At point B the angle of the slant will be 300 from vertical, boring 26.5 to 27 feet, placing the sample point horizontally 13 feet southeast of point B at a vertical.depth below surface of 23 to 24 feet. A sample will then be obtained of relatively undisturbed native soil approximately 1 to 1.5 feet beneath the fill at the northern end of the western UST. At point C the angle of the slant will be 440 from vertical, boring 24 to 25 feet, placing the sample point horizontally 16 feet northwest of point C at a vertical depth below surface of 18 to 19 feet. A sample will then be obtained of relatively undisturbed native soil approximately I to 1.5 feet beneath the fill at the southern end of the middle UST. At point D the angle of the slant will be 350 from vertical, boring 34.5 to 35.5 feet, placing the sample point horizontally 19.5 feet southeast of point D at a vertical depth-below surface of 28.5 to 29 feet. A sample will then be obtained of relatively undisturbed native soil approximately I to 1.5 feet beneath the fill at the northern end of the middle UST. At point E the angle of the slant will be 37°from vertical, boring 23.5 to 24 feet, placing the sample I point horizontally 14.5 feet northwest of point E at a vertical depth below surface of 18.5 to 19.5 feet. A sample will then be obtained of relatively undisturbed native soil approximately 1 to 1.5 feet beneath the fill at the southern end of the eastern UST. At point F the angle of the slant will be 250 from vertical,boring 31 to 32 feet, placing the sample point horizontally 14 feet southeast of point F at a vertical depth below surface of 27.5 to 28.5 feet. A sample will then be obtained of relatively undisturbed native soil approximately 1 to 1.5 feet j beneath the fill at the northern end of the eastern UST. I Samples will be obtained through the hollow stem augers using a California Split Spoon sampler that will hold three clean 2-inch by 6-inch brass sleeves. Once the augers have reached the desired sample depth the inner bit assembly will be removed and the sampler will be driven 1.5 feet into relatively undisturbed soil, filling the three brass sleeves. The top sleeve will not be used for sample analysis. The two bottom sleeves will be field screened using a photo-ionizing detector (PID) with a 10.6 ev bulb. The soil sample sleeve showing the highest PID response will be preserved for laboratory analysis as described below. The soil from the other two sleeves will be placed into a zip lock baggy which will then be sealed and examined for lithology, staining and later PID response. 2 R-603 UST WP 2/23/99