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interim Site Assessment Report {'}s` Village West Marina W.W. Irwin Project 033016.00 15 inches thick and may serve as a confining layer to the underlying ground water. Data provided by the California Department of Water Resources shows that the depth to first ground water may be as shallow as 20 feet bgs in the vicinity of the site. Ground water was not encountered during the excavation of the tank pit that extended to approximately 18 to 20 feet bgs, however, the clay layer was encountered at the bottom of the excavation. SITE HISTORY On April 21, 1993, two 10,000-gallon underground leaded gasoline storage tanks and one 5,000-gallon underground diesel fuel storage tank were removed from the subject site. Evax Technologies, Inc., under the supervision of Ms. Pamela Violett, SJCPHS inspector, inspected the tanks and collected soil samples from beneath the fill end and non-fill end of each leaded gasoline tank and one sample from beneath the fill end of the diesel tank. All samples were retrieved from the floor of the excavation located at 13.5 feet bgs. Additionally, two soil samples were collected from the soil stockpile which was placed next to the excavation. The stock pile was later moved to the south end of the property where it still remains. Analytical results of the soil samples, revealed that elevated levels of total purgeable hydrocarbons (TPH-G) and total extractable petroleum hydrocarbons (TPH-D), benzene, toluene, ethyl benzene, xylenes (BTEX) and lead were present in the samples collected from the excavation and from the stockpile. EXCAVATION ACTIVITIES The overexcavation of the former tank pit was initiated on July 16, 1993, by equipment operator, Mr. Mark Burns, and a W.W. Irwin staff geologist, as requested and contracted by the Pegasus Group. The work was supervised periodically by Mr. Michael Collins, SJCPHS inspector. As the excavation proceeded, soil samples were collected for lithologic analysis and organic vapor analysis (OVA) meter readings were taken in order to direct the excavation by determining the level of contamination and the direction of migration. The excavation was expanded slightly in all directions from the original tank pit to an area approximately 35 feet square and to a depth of approximately 18 to 20 feet below surface grade. The excavation was baited when the excavator reached the limits of its extension and when the northern wall became inaccessible. Ground water was not encountered. An estimated 260 cubic yards of newly excavated soil was removed from the tank pit and stored at a location on the south side of the property, separate from the soil stockpiled during the tank removal operation (shown in Figure 2). 2