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The Site is largely isolated from impact from most areas of potential contamination by its location on a peninsula bounded by the Stockton Deep Water Channel and Mormon Slough. Leaks at underground storage tanks at adjoining facilities were successfully remediated and the sites are closed. The McCormick and Baxter wood preserving company was located to the south of the site and on the other side of Mormon Slough at 1295 W. Washington Street. The McCormick and Baxter site has been designated a Superfund site and is currently being investigated for the lateral and vertical extent of contamination. Soil borings were installed on the site to determine if contaminants were present that far north. Marie Lacey, the EPA Remedial Project Manager for the McCormick and Baxter Superfund Site, indicated in a phone conversation with AGS on October 24, 2000 that the analyses of the soil borings showed no contamination at the site and further sampling of the property would most likely not be required. 1.2 Site Geology The Site lies within the flood plain of the San Joaquin River and at the intersection of Mormon Slough and the Stockton Deep Water Channel. Wagner, et. al. (1990) shows it to be near the boundary between the arkosic alluvium of the Modesto formation and the Dos Palos floodplain deposits. These sediments, of Quaternary age, overlie late Triassic to early Tertiary marine and non-marine clastic sediments. The site geology consists of from seven to twenty feet of unconsolidated clays and silts overlying unconsolidated sand containing minor amounts of silt and gravel. This sequence is what one would expect to find in the low energy environments which prevailed in the delta of the San Joaquin River when the sediments were deposited. 1.3 Site Hydrology Tides and seasonal precipitation influence the depth to the water table. However, depending on the Site relief, it is generally less than ten feet below the surface. The ground water gradient at the Site is generally to the south or southeast, sloping from the Stockton Deep Water Channel toward Mormon Slough. Because of the relatively flat relief of the site and the fact that some of the site is unpaved, it is believed that most of the precipitation infiltrates into the ground. The center of the Site has a low lying area that has a drainage culvert for draining storm water to the southwest into Mormon Slough. American Geological Services,Inc. CA99DE-095 4