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B. ENVIRONMENTAL IMPACTS <br /> Future peak ground accelerations in the project area are estimated to be on the order of <br /> 0.1g to 0.2g. These motion estimates are based on a 7.25-magnitude earthquake <br /> occurring on the Hayward fault. Peak ground accelerations caused by a 6.5-magnitude <br /> earthquake on the closer Midland fault are estimated to be smaller than those for the <br /> larger event on the Hayward fault. <br /> ISSUE: Seismic Ground Shaking <br /> There is a strong liklihood that the site will experience seismic ground shaking during <br /> the life of the project. The ground shaking will impose lateral shearing forces on the <br /> planned structures. The structures will be more susceptible to the effects of ground <br /> shaking during construction. <br /> Significance: Potentially Significant. <br /> Mitigation: <br /> 8-1. Design the structure in conformance with all applicable <br /> building codes to support the anticipated earthquake loads. <br /> If strong ground shaking occurs during construction, repairs <br /> may need to be performed at that time. <br /> Significance After Mitigation: Not Significant. <br /> ISSUE: Ground Rupture <br /> There are no known active faults or extensions of faults in the immediate vicinity, <br /> therefore,the risk of ground rupture is considered nil. <br /> Significance: Not Significant. <br /> Mitigation: Not required. <br /> ISSUE: Landsliding <br /> The topography of the site is relatively flat; therefore, the risk of seismically induced <br /> landslides or lateral spreading is considered very low. Slumping could occur in theut <br /> sides of soil stockpiles on the vacant property east of the site,bthis is not expected to <br /> impact the project. <br /> Significance: Not Significant. <br /> Mitigation: Not required. <br /> ISSUE: Settlement Caused by Liquefaction or Densification <br /> Liquefaction is the phenomenon in which soil temporarily loses strength due to the <br /> buildup of excess pore-water pressure caused by seismic shaking. Soil most susceptible <br /> to liquefaction is loose, clean, saturated sand. According to Kleinfelder, Inc., the <br /> eotechnical firm that recently completed an investigation on the site (Kleinfelder, <br /> 993), there is a low risk of liquefaction at the site. The surface silty sand covering <br /> portions of the site are loose,but above the water table. <br /> 8-2 <br />