2020-065 - Adopting Environmental Findings of Fact

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The Warner Redhill Mixed -Use Project CEQA Findings of Fact Impact Finding: The Project would not be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the Project, and potentially result in on- or off -site landslide, lateral spreading, subsidence, liquefaction or collapse (Draft EIR at p. 5.5-10). Facts in Support of Findings: The elevation of the site ranges from approximately 57 to 65 feet msl and the site is not located on or adjacent to a hillside or slope. Based on the relatively flat topography of the site, lack of a free face nearby and general lack of potentially liquefiable layers in the upper 40 feet, the Geotechnical Report determined that the potential for lateral spreading on the site is low. Thus, impacts related to lateral spreading would be less than significant. Also, as described previously, impacts related to landslides would not occur. The Geotechnical Report identified that seismic inducted settlement onsite could be 2 inches or less; and differential seismic settlement is estimated as 1-inch over a horizontal span of about 40 feet The Geotechnical Report prepared for the Project site provides CBC seismic structural design criteria that are specific to the onsite soils, including the soils settlement and minor ground subsidence conditions that could occur. The Project includes excavation and recompaction of soils, and development of foundation systems in compliance with the CBC, as included as PPP GEO-1, which would require proper construction of building foundations to reduce impacts related to settlement and subsidence would not occur onsite. Also, the CBC, as currently adopted in the City's Municipal Code Chapter 8, Article 2, Division 1, requires that a California Certified Engineering Geologist or California -licensed civil engineer provide site -specific engineering data for the proposed structures, which are reviewed by the City for appropriate inclusion as part of the building plan check and development review process. Compliance with the requirements of the CBC and City's municipal code for structural safety through implementation of as included as PPP GEO-1 would reduce potential impacts to a less than significant level. Plans, Program and Policies: PPP GEO-1: CBC Compliance. As listed previously. Impact Finding: The Project would not be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial risks to life or property (Draft EIR at 5.5-10). Facts in Support of Findings: The Project site contains medium stiff to hard clays with variable sand content, as well as loose to medium dense, moist to wet clayey and silty sands. Due to the clay content in the onsite soils, the site has the potential for expansion. However, as described in the Draft EIR Section 3.0, Project Description, the soils onsite would be excavated to a minimum of 5 feet below the bottom of the building foundations and 5 feet beyond the building perimeters, reconditioned, and recompacted as engineered fill to support the proposed building structures. As part of reconditioning the compacted engineered fill, the soils would be moisture conditioned, as required by the CBC for expansive soils. Furthermore, prior to approval of construction, an engineering level design geotechnical report is required to be prepared and submitted to the City that details the project designs that have been included to address potential geotechnical and soil conditions pursuant to the CBC requirements, that are included in the City's Municipal Code Chapter 8, Article 2, Division 1, and implemented by PPP GEO-1. Compliance with the CBC, through design level geotechnical specifications that City of Santa Ana 15 May 2020