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r r Clay ton Copies of these permits are provided in Appendix A. 4.i, HHEA=AhM aAFFly PLANNING According to the laboratory analysis of soil samples collected from the subject site during installation of the monitoring wells, the possible contaminants to be encountered during the soil excavation were petroleum hydrocarbons as gasoline, toluene, ethylbenzene, xylenes, and oil and grease. Benzene was not detected in any of the samples. In addition to the chemical hazards posed by the presence of these chemicals, some physical hazards related to deep excavations and soil aeration were considered. To account for these chemical and physical hazards, Clayton developed a health and safety plan. This plan was provided to the contractor and workers onsite during a health and safety briefing conducted prior to commencement of work onsite. A copy of this plan is provided in Appendix B. 5.0 SOIL EXCAVATION AkM AERATION Soil excavation started on July 23, 1990, near the gasoline island concrete pad, which was still in place. Fuel Oil Polishing Company excavated the soil using a . Case excavator, a 12-yard dump truck, and a Case 450 truck loader. Clayton monitored excavated soils with an organic vapor meter (OVM) to detect hydrocarbons. On July 26, 1990, after about 1,000 cubic yards of soil were excavated, Clayton collected five soil samples from the walls of the excavation. Analysis of these samples revealed further gasoline and oil and grease contamination near the north and east walls of the excavation. Excavation continued on the north and east sides of the excavation. A total of about 1,650 cubic yards of soil were excavated to achieve removal ofall soils with concentrations exceeding 10 mg/kg of gasoline and 100 mg/kg of oil and grease. Aeration of the excavated soils involved spreading the soils in thin layers (approximately 1 foot high) onto a polymeric liner. This liner was used to prevent the contaminants in the excavated soil from mixing with surface soil. The aerating soils were periodically turned over. 5.1 EXCAVATION PIT SAMPLING A total of 13 soil samples were collected from the excavation pit. Ten samples were collected from the walls of the initial excavation to confirm that all contaminated soils had been excavated. All samples were collected in 2-inch . diameter brass tubes, covered with aluminum foil, capped, and sealed with tape to prevent volatile hydrocarbon escape. These samples were placed on dry ice and transported to Clayton s state-certified laboratoryfor analysis.- The.10 samples collected from the walls of the excavation were analyzed by the following methods: • EPA Method 5030/8015-8020, for TPH as gasoline and for BTEX �l -3- :gsx.otreEa moms' WMENEEMINEEMIMMI=1= al'INEM,