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Boring G-3 was drilled with air -rotary equipment to a depth of 170 feet, where borehole stability problems necessitated switching to mud -rotary drilling in order to advance the boring to the total depth of 215 feet. The boring penetrated predominantly sandy clay to 104-1/2 feet, below which predominantly sands and gravels were encoun- tered with intervening clay interbeds (see log in Appendix A). 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. C. STRUCTURE There are no apparent significant geologic structural features either exposed at the site or within the underlying strata. The alluvial deposits comprising the subsurface are structurally undeformed and lithologically gradational, both vertically and laterally. Sedimenta- ry units between the Quaternary alluvial deposits and deep Sierran basement rocks are tilted gently to the west towards the axis of the San Joaquin Valley. Secondary structural features, such as fractures and joints, were not detected in soil samples retrieved by coring. Minor textural fea- tures, such as microfractures and fine rootholes, were observed in a limited number of samples. A review of published maps indicate no known Holocene faults crossing the site or its surrounding vicinity. D. SEISMICITY EMCON evaluated the seismicity of the site and vicinity to determine the Maximum Probable Earthquake and its expected peak ground accelera- tion. Information from the study will be used to perform stability analyses of intermediate and final landfill, embankment, and cut slopes and to design stable leachate control and associated features. Findings of the seismic study area presented in Appendix C. PJ9 9390206.00D 8