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y i Y KEI-J92-02 05.Rl October 6, 1992 Page 2 RECENT FIELD ACTIVITIES KEI 's field work was conducted on April 22 , 1992 , when two underground diesel storage tanks (with individual capacities of 20, 000 and 10, 000 gallons) were removed from the site. The tanks were made of steel, and no apparent holes or cracks were observed in the tanks. Ms. Pamela Violett of the SJCPHS was present during tank removal and subsequent soil sampling. Ground water was encountered in the fuel tank pit at a depth of approximately 10. 5 feet below grade, thus prohibiting the collec- tion of any soil samples from immediately beneath the tanks. Five soil samples, labeled SWI through SW5 , were collected from the sidewalls of the fuel tank pit at depths ranging from 9 . 5 to 10 feet below grade. The undisturbed samples were collected from bulk material excavated by backhoe. The samples were placed in clean, two-inch diameter brass tubes, sealed with aluminum foil, plastic caps and tape, and stored in a cooled ice chest for delivery to a state-certified laboratory. Sample point locations are as shown on the attached Site Plan. After soil sampling was completed, approximately 7 , 000 gallons of ground water were pumped from the fuel tank pit. On April 29, 1992 , one water sample (labeled W-1) was collected from the fuel tank pit in four clean glass VOA vials and a one-liter amber bottle. The water sample was stored and delivered as described above. Ms . Violett was present during the water sampling Upon review of the analytical results, KEI proposed to perform additional lateral excavation in the vicinity of sample SW2 (the southeast sidewall of the tank pit) , per KEI ' s proposal (KEI-P92- 0205 .P2) dated May 13 , 1992 . On July 30 , 1992 , the proposed additional excavation of the southeast sidewall was completed (approximately 3 feet laterally) Per the request of Mr. Harlin Knoll of the SJCPHS, four soil samples (labeled SW2-A, SW2-B, SW2-C, and SW2-D) were collected from the southeast sidewall of the additionally excavated tank pit at depths ranging from 8 . 75 to 10 . 75 feet below grade. The samples were also collected from bulk material excavated by backhoe and handled as previously described. Sample point locations are shown on the attached Site Plan. SUBSURFACE CONDITIONS The subsurface soils exposed in the excavation consisted primarily of sandy clay. On April 22 , 1992 , ground water was encountered in the tank pit at a depth of approximately 1.0 . 5 feet below grade, and