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FAW <br /> April 7, 1992 �AA �� <br /> . ARCO Service Station No 760, Lodi, California <br /> Results of laboratory analyses of soil samples collected from the bonngs during drilling are <br /> presented in Tables 2 and 3 Laboratory results indicated that soil containing waste oil was <br /> restricted to depths less than X25 feet bielow grade in bonny B-f d less than 15 feet Belov� <br /> grade-in bonngs_B_2_9aMnB` (Table 2) However, hydrocarbon odor was noted in the soil <br /> samples by the staff geologist during drilling at or above 25 feet below grade, therefore <br /> drilling was continued Results--indicated-concentrations_of-3,600-ppm-of-TPHg-and 4,300 <br />� pm of TPHd were_detected_an the soil sample collected from 25 feet below grade in Bonn <br /> Gasoline hydrocarbons were not detected in the soil samples collected from 45 and <br /> 55 feet below grade in borings B-1 and B-2 <br /> r <br /> Cadmium, chromium, lead, and zinc were detected in the samples from bonngs B-1 through <br /> B-3 at total concentrations below the respective Soluble Threshold Limit Concentrations <br /> outlined in Title 22, California Code of Regulations, Section 66699 (Table 2) The <br /> concentrations of these metals probably represent naturally-occurring soil conditions I <br /> kqi- <br /> Preliminary Tank Replacement Assessment <br /> In October 1990,bonngs B-4, B-5,and B-6 were dnlled around the perimeter of the existing <br /> tanks (designated T1, T2, and T3 on Plate 2), bonngs B-7 and B-8 were drilled in the area <br /> where the new tanks were proposed (Plate 2) The locations of bonngs B-4 through B-7 <br /> were selected using ARCO's Preliminary Tank Replacement Assessment guidelines <br /> (RESNA, Inc , December 18, 1990) Sediments from the bonngs drilled near the gasoline <br /> tank cavity were logged as fine- to coarse-grained sand with a trace amount of fine-grained <br /> gravel Borings B-4, B-5, and B-6 were terminated at 26, 61, and 31 feet below grade, <br /> respectively Borings B-7 and B-8 were terminated at 21 feet below grade Analytical <br /> results of soil samples collected from these bonngs are presented in Table 3 R6su1ts of soil <br /> samples from analyses indicated residual hydrocarbons were not detected in-bonngs-B-4 <br /> through B-8 <br /> 38048-s 3 <br /> i <br />