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SAN LEANDRO SHORELINE DEVELOPMENT DRAFT EIR <br />CITY OF SAN LEANDRO <br />GEOLOGY, SOILS, AND SEISMICITY <br />Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake <br />Fault Zoning Map issued by the State Geologist for the area or based on other substantial <br />evidence of a known fault. Refer to Division of Mines and Geology Special Publication 42. <br />■ Strong seismic ground shaking. <br />■ Seismic -related ground failure, including liquefaction. <br />■ Landslides. <br />2. Result in substantial soil erosion or the loss of topsoil. <br />3. Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the <br />Project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction, <br />or collapse. <br />4. Be located on expansive soil, as defined in Table 18-1-b of the Uniform Building Code (1994), creating <br />substantial risks to life or property. <br />5. Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater <br />disposal systems where sewers are not available for the disposal of wastewater. <br />4.5.3 IMPACT DISCUSSION <br />This section analyzes potential project -specific and cumulative impacts to geology and soils. <br />GEO-1 The Project could expose people or structures to potential substantial <br />adverse effects, including the risk of loss, injury, or death involving <br />strong seismic ground shaking; seismic -related ground failure; including <br />liquefaction and lateral spreading. <br />Large earthquakes could generate strong to violent ground shaking at the Project site and could cause <br />damage to structures and threaten public safety. San Leandro lies within a seismically active region that <br />includes much of western California. Several active faults are present in the region, including the Hayward, <br />Calaveras, and San Andreas faults. These faults are capable of generating large earthquakes that could <br />produce strong to violent ground shaking at the Project site. WGCEP has estimated that there is a 63 <br />percent chance of a large earthquake (magnitude 7 or greater) in the Bay Area by the year 2036.13 At <br />present, it is not possible to predict precisely when or where earthquakes will occur on these faults. <br />During an earthquake, seismic risk to a structure would depend on the distance to the earthquake <br />epicenter, the characteristics of the earthquake, the subsurface conditions underlying the structure and <br />its immediate vicinity, and the characteristics of the structure. The Project site is located on relatively <br />thick, alluvial deposits that could cause amplification of ground shaking. In addition, a thin layer of soft <br />Bay Mud overlies the alluvium in the western portion of the Project site and could increase the shaking <br />13 Working Group on California Earthquake Probabilities (WGCEP), 2008. "The Uniform California Earthquake Rupture <br />Forecast, Version 2 (UCERF 2): for 2007-2036," U.S. Geological Survey Open File Report 2007-1437; CGS Special Report 203; and <br />SCEC Contribution #1138.. <br />4.5-10 DECEMBER 2014 <br />