75B - PH ADOPT RESO FOR PR NO 15-6827

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L S A FAIRVIEW BRIDGE REPLACEMENT AND STREET IMPROVEMENTS (9TH STREET TO 16TH STREET( PROJECT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION SANTA ANAL CALIFORNIA MAY 2020 3.7.2 Impact Analysis a. Would the project directly or indirectly cause potential substantial adverse effects, including the risk of loss, injury, or death involving: i. Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. Less Than Significant Impact. No active surface faults are mapped or known to cross Santa Ana, and Santa Ana is not located in an Alquist-Priolo Earthquake Fault Zone. However, Santa Ana is in close proximity to two major faults: the Newport -Inglewood Fault Zone and the Whittier - Elsinore Fault Zone. The San Andreas and Raymond Faults are also proximate to Santa Ana. However, the Project area is not located on any active faults or any inactive fault lines. The proposed Project includes roadway improvements and would not include the construction or rehabilitation of structures for human occupancy. Therefore, potential for the exposure of people or structures to potential substantial adverse effects related to fault rupture as provided in the Alquist-Priolo Earthquake Fault Zoning Act is less than significant. No mitigation is required. ii. Strong seismic ground shaking? Less Than Significant Impact. Strong seismic ground shaking has the potential to occur in the Project area and in the surrounding area due to high rates of seismic activity throughout Southern California. The extent of ground shaking associated with an earthquake depends on the size of the earthquake and the geologic material of the underlying area. As discussed in Response 3.7.2(a)(i), no active surface faults are mapped or known to cross Santa Ana; however, Santa Ana is subject to seismic shaking from faults located outside Santa Ana. The Project improvements would comply with applicable provisions of the most recent California Building Code (CBC), as well as City roadway design requirements, including requirements regarding seismic design and structural features. These regulations detail specific measures, including seismic design parameters, to minimize the risk of loss, injury, or death resulting from strong ground shaking. With adherence to seismic engineering and design criteria, seismic ground -shaking hazards at the proposed Project would be less than significant. No mitigation is required. iii. Seismic -related ground failure, including liquefaction? Less Than Significant Impact. Liquefaction occurs when shallow, loose, unconsolidated, fine- to medium -grained sediments saturated with water are subjected to shaking as a result of an earthquake. This causes the soils to lose cohesion, leading to liquefaction. The possibility of seismic -related liquefaction occurring in the Project area is dependent on the occurrence of a substantial earthquake in the vicinity, the presence of sufficient groundwater to cause high pore 3-40 7 584,4ND\Final ISMND\Fairview Street Bridge Final ISMND.docx (OS/26/2O)