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The exploratory drilling performed during this and previous investigations con- firmed subsurface site conditions to be consistent with the regional setting dis- cussed above. Beneath surficial soils, all borings penetrated interlayered silts, clays, and sands to their entire depth (see Appendix A). Logs of the borings are also included in Appendix A. As the cross-sections in Appendix A indicate, lithologies within the upper 100 feet vary widely across the site. Two shallow borings, P-1 and P-2, were drilled to supplement existing data on sediments within and immediately below potential soil excavations. Boring P-1, located in the northern portion of the site, penetrated interlayered silts, clays, silty sands, and clayey sands to a depth of 25 feet. Below 25 feet, the boring encountered poorly to well graded, dense clean sands. Such a thick deposit of clean sand is atypical for the site and was not discovered in any other borings on site. Bor- ing P-2, located in the southern section of the site, penetrated interlayered silts and sandy silts, as well as very dense sands and silty sands to the entire depth. Thicknesses of layers ranged from 1 -1 /2 to 5 feet. Boring P-3 was drilled to ex- plore intermediate depths and encountered primarily fine-grained soil to its total depth of 89 feet. Deep Borings G-1, G-2, and G-3 were drilled to obtain samples of ground water beneath the proposed landfill site and to characterize the intervening materials. Intervening deposits consisted of heterogeneous interlying silt, clay, and sand. Finer -grained deposits predominated. Boring G-2 encountered primarily fine- grained soil in the upper 40 feet, sandy soils below 80 feet, and predominantly sandy clays and silty sands, with several gravelly layers, below 101 feet. Boring G-3 penetrated predominantly sandy clay to 104-1/2 feet, below which predominantly sands and gravels were encountered with intervening clay in- terbeds. Sand is typically fine to very coarse grained with minor fine gravel of predominantly metamorphic, with lesser granitic constituents. Some intervals are partially cemented with secondary clay filling voids between grains. There are no apparent significant geologic structural features either exposed at the site or within the underlying strata. The alluvial deposits comprising the sub- surface are structurally undeformed and lithologically gradational, both vertically and laterally. Sedimentary units between the Quaternary alluvial deposits and PJ9 9390218A.00W 21 Rev. 0 July 20, 1989