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5.0 DESCRIPTION OF FIELD ACTIVITIES Prior to commencement of on-site activities, a daily tailgate Health and Safety meeting was conducted by the Project Manager to discuss potential health and safety risks and the appropriate precautions required to reduce such risks All field personnel were made familiar with the Health and Safety Plan (Appendix III) On-site field activities began on October 1, 1994 with Capstone securing the elevator car above the work area with a welded steel frame designed by Kramer & Associates structural engineers The concrete floor slab beneath the elevator car was broken up and removed to expose the contaminated soil for removal This was accomplished with a pneumatic hand-held jackhammer After removal of the concrete slab, excavation of the soils began The soil excavation was performed utilizing a 4,000 PSI Portable Drill Rig designed for limited access drilling On October 7, 1994, dust after drilling commenced on the first boring, the drill rig sank approximately 3 feet into a void beneath the top layer of soil Work was stopped while the drill rig was removed and the void could be inspected by a structural and a geotechnical engineer A structural engineer from Kramer & Associates of Tustin, California and a geotechnical engineer from Kleinfelder, Inc inspected the void on October 11, 1994 It was determined that a caving saturated sand layer was encountered at approximately 5 to 7 feet below the elevator . subfloor It was also determined that no structural damage to the building was anticipated provided a prescribed drilling order of a limited number of holes per day was followed and drilling operations could proceed Engineering reports are presented in Appendix IV Drilling activities resumed on October 12, 1994 A wooden platform was constructed and installed above the void to provide a secure support platform for the drill rig An area approximately 9 feet by 6 feet with approximate pier depths of 10 to 20 feet was excavated by boring holes side by side within the elevator pit The drill depths of the piers were determined by soil sample analytical results provided by a mobile on-site lab The excavated soil was stockpiled in a roll-off bin on the northeast side of the property The soils encountered during the augering were brown silty sands grading to a grayish brown clay layer Groundwater was encountered at 9 feet below surface grade (bsg) The depth to water below the elevator pit was approximately 5 feet During the soil excavation, two (2) different sizes of flight augers were utilized to maximize the amount of contaminated soil removed The largest borings were made with an 18-inch flight auger CRC collected confirmatory soil samples at 5-foot intervals in every 18-inch boring In- fill borings were drilled in the spaces between the 18-inch borings with a 14-inch flight auger The 14-inch borings were drilled to 15 feet before sampling was performed The sampling was conducted under county oversight by Health Specialist Steve Sasson A mobile field laboratory was set up on-site to provide CRC with immediate soil sample results so decisions could be made when to stop advancing each boring The borings were stopped when field screened sample results were less than 100 ppm TPH as hydraulic fluid by EPA Method 8015M CRC Environmental Risk Management Inc B Project q 3620-061-4 George Bravante,Receiver 2233 Grand Canal Boulevard January 19 1995 3 Stockton California