NS-3092 - Zone Change for 1801 East Chestut Ave

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SANTA ANA REZONE PROJECT INITIAL STUDY/MITIGATED NEGATIVE DECLARATION southwest.30 Therefore, the probability of surface fault rupture occurring from an active fault is considered low.Additionally, the proposed project would be required to follow seismic design parameters based upon the 2022 CBC for the construction of the proposed solar shade structures, which would further reduce impacts related to rupture of a known earthquake fault.As such, impacts are considered less than significant. ii) Strong seismic ground shaking? Less than significant impact. Seismic ground shaking is influenced by the proximity of the site to an earthquake fault, the intensity of the seismic event, and the underlying soil composition.A geologic hazard likely to affect the project site is ground shaking as a result of movement along an active fault zone in the vicinity of the subject site.Although the site is not located on an earthquake fault, seismic ground shaking would occur with activity along active faults in the vicinity, as listed in question a) i), above.As the proposed project is a parking lot, it would not result in potential impacts related to seismic ground shaking; in the construction of the proposed solar shade structures, impacts would be less than significant with implementation of seismic design requirements of the 2022 CBC. iii) Seismic-related ground failure, including liquefaction? Less than significant impact. Liquefaction is a mode of ground failure that results from the generation of high water pressures during earthquake ground shaking, causing loss of shear strength. Liquefaction is typically a hazard where loose sandy soils exist below groundwater. The California Geological Survey(CGS) has designated certain areas within Southern California as potential liquefaction hazard zones. These are areas considered at risk of liquefaction-related ground failure during a seismic event, based upon mapped surficial deposits and the presence of a relatively shallow water table.31 The project site is not located in a CGS Liquefaction Hazard Zone; the nearest CGS Liquefaction Hazard Zone is located approximately 0.2 mile south of the project site.32 This zone is defined as an area where historical occurrence of liquefaction or local geological, geotechnicai, and groundwater conditions indicate a potential for permanent ground displacements such that mitigation would be required.According to the General Plan Safety Element, the areas of the City that are susceptible to liquefaction are in close proximity to the Santa Ana River.The project area is approximately 4 miles from the Santa Ana River. The proposed project includes paving of an existing overflow gravel parking lot and associated access roadway. In addition, there would be a separate publicly accessible area in the southern portion of the 30 United Slates Geological Survey(USGS).2025. U.S.Quaternary Faults.Website: https:/Iusgs.maps.arcgis.com/apps/webappviewer/index.himl?id=5a6O38b3a1684561 a9bOaadf88412fcf.Accessed February 6,2025. 3d United States Geological Survey(USES).2025. U.S.What is liquefaction?Website:https://www.usgs.govlfagstwhat- liquefaction.Accessed February 6,2025. 32 California Department of Conservation(DOC).2025. Earthquake Zones of Required Investigation.Website: https:!/maps.conservation.ca.gov/cgstinformationwarehouse/egzapp/.Accessed February 6,2025. FCS (� 53 Htt0a://ad-in na tl¢ ,hacepaint.—J,ftes/PublicaU—Ste/Sh aced 0ncuments/PubRC3tjL S/Client[PNJNI/0327)03270f197/ISMMD/03270047 Sd UAna R—ne PrQnd�B ce No. NS-3092 Page 65 of 118