Reso PC15-01 PC Reso (3051 ) to Adopt Initial Study-Mitigated Negative Declaration - La Palma

Browse Search

3.0 Environmental Impact Checklist Priolo fault zone for the San Andreas Fault and would not expose people or buildings to risks of fault rupture. a.ii)Expose people or structures to potential substantial adverse effects,including the risk of loss,injury, or death involving strong seismic ground-shaking? Less-than-Significant Impact. While the project is not within an EFZ,the San Francisco Bay Area region has several known seismically active faults,making the region subject to strong ground-shaking in the event of an earthquake. Earthquakes along several nearby active faults in the region could cause moderate to strong ground shaking at the project site.The intensity of the earthquake ground motions and the damage done by them would depend on the characteristics of the generating fault, distance to the fault and rupture zone, earthquake magnitude, earthquake duration, and site-specific geologic conditions.Given that the entire San Francisco Bay Area region is subject to strong seismic ground shaking during a large earthquake event, the project would not expose people or structures to any greater risks involving seismic ground shaking than would other development located in the region. While the potential for seismic ground shaking cannot be eliminated,the project structures would be required to comply with the 2013 California Building Code(CBC) and other applicable standards and practices for earthquake resistant construction. Compliance with these standards and practices reduces the risks associated with strong seismic ground-shaking at the project site. Therefore, impacts related to seismic ground-shaking would be less than significant. a.iii)Expose people or structures to potential substantial adverse effects,including the risk of loss,injury, or death involving seismic-related ground failure,including liquefaction? No Impact. Liquefaction is a phenomenon in which saturated soils lose their strength and stiffness as a result of seismic-related ground shaking. When liquefaction occurs, the ground behaves like a liquid,instead of a solid, causing the ground to sink or even pull apart.The project site is located in a general area of moderate liquefaction susceptibility as designated by the Association of Bay Area Governments(ABAG) (ABAG 2014a). The Geotechnical Investigation and Pavement Design Report(Appendix C)prepared for the project analyzed exploratory soils borings to determine whether potentially liquefiable soils were present underlying the project site.The results concluded that there are no liquefiable soils layers at the depths present underlying the project site.Thus, implementation of the project would not expose people or structures to risks from liquefaction. a.iv) Expose people or structures to potential substantial adverse effects,including the risk of loss,injury, or death involving landslides? No Impact.Landslides are related to instabilities in slopes and can be induced by earthquakes or heavy amounts of rainfall.Implementation of the project would not pose risks from landslides on-or off-site as the project site and its surroundings are relatively flat. There are no steep slopes or hillsides on the project site that would be susceptible to landslides. Implementation of the project would not expose people or structures to risks from landslides on-or off-site. La Palma Subdivision Project Final Initial Study/Mitigated Negative Declaration 33