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INTRODUCTION • • This report prepared by Touchstone Developments is intended to document soil excavation at the former Chevron service station #9-0959, located at 103 West 11th Street in Tracy,California(Figure 1). Soil excavation was performed on July 12, 1993 following underground fuel storage tank removal. SITE ACTIVITIES Soil excavation and removal of suspected contaminated soil was performed by Golden West Builders of Brentwood,California. A Touchstone representative was on site to observe excavation activities and to collect soil samples from the excavation. Excavation and sampling was performed under the direction of Kenneth Kan of Chevron U.S.A. Two separate areas were excavated as illustrated in Figure 2. Area A extended north from the previous tank removal excavation approximately 10 feet and west from the sidewalk approximately 15 feet. Following excavation, four soil samples were obtained. Samples OX-1-5' and OX-3-5' were collected from the north and east sidewalls at a depth of 5 feet below grade. Samples OX-2-8' and OX-4-8' were collected from the north and east sidewalls at a depth of 8 feet below grade. Sample locations are shown in Figure 2. Area B was then excavated south from the previous tank removal excavation approximately 10 feet and west from the sidewalk approximately 5 feet. Soil samples were then collected from the sidewalls of the excavation. Samples OX-5-5'and OX-6-S'were collected at 5 feet below grade and OX-7-8' and OX-8-8' were collected at 8 feet below grade. Approximately 50 cubic yards of soil was generated and stockpiled on site with the soil generated from the previous tank removal. The soil is represented by samples SP-13, SP-14, SP-16, SP-17, and is currently stockpiled on site. Both excavations reached a total depth of approximately 8 feet below grade, ground- water was observed at approximately 8.5 feet below grade. SOIL SAMPLING Soil samples were collected from the excavator bucket by removing the top few inches of soil and pushing a clean, six-inch-long (two inches in diameter) brass sample tube into the soil until completely full. The ends of the tubes were covered with teflon tape and sealed with plastic end caps. The samples were then labeled, placed in a cooler with blue ice, entered on a Chain-of Custody form and transported to Superior Precision Analytical, a State-certified laboratory. Soil samples collected from the excavation were analyzed for Petroleum Hydro- carbons calculated as Gasoline (TPH-Gasoline) according to EPA Method 8015 (Modified) and Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) according to EPA Method 8020. A copy of the analytical laboratory reports and Chain-of- Custody forms are presented in Appendix A. Touchstone Developments . August 11,1993 . Project u 0959-1