RES 211231 Exhibit A - Laserfiche WebLink

Environmental Checklist and City of Pleasanton–10x Genomics Project Environmental Evaluation Initial Study/Mitigated Negative Declaration 70 FirstCarbon Solutions Https://adecinnovations.sharepoint.com/sites/PublicationsSite/Shared Documents/Publications/Client (PN-JN)/2148/21480024/ISMND/wp/21480024 10x Genomics Project Full Screencheck ISMND.docx All structures would be designed using sound engineering judgment and the latest California Building Standards Code (CBC) requirements, at a minimum. The Geotechnical Investigation provides additional recommendations related to earthwork and site preparation, foundation design, floor slabs, pavement and concrete design, and landscaping. MM GEO-1 would ensure implementation of the recommendations from the Geotechnical Investigation, which would reduce hazards associated with strong seismic ground shaking to less than significant. iii) Seismic-related ground failure, including liquefaction? Less than significant impact with mitigation incorporated. Liquefaction can cause the soil beneath a structure to lose strength, which may result in the loss of foundation-bearing capacity and which could cause a structure to settle or tip. Liquefaction can also result in the settlement of large areas because of the densification of the liquefied deposit. According to the General Plan as well as the site-specific Geotechnical Investigation, the project site is not in a liquefaction zone, but the center of the project site is approximately 950 feet west and 1,300 feet south of an area designated as a liquefaction hazard zone. Although the site is outside the mapped liquefaction area, the medium- dense sand present at the site below the design groundwater level may be susceptible to liquefaction.42,43 The Geotechnical Investigation includes an analysis of the site’s liquefaction potential, performed in accordance with Special Publication 117A, titled Guidelines for Evaluating and Mitigating Seismic Hazard Zones in California.44 According to the analysis, some of the thin, medium-dense sand layers below the medium-stiff to stiff clay that is located generally between about 30 and 50 feet below ground surface (BGS) are susceptible to liquefaction during a strong earthquake. The analysis estimated that about 0.5-inch of liquefaction-induced settlement could occur at the project site, but that the potential hazards associated with liquefaction and settlement could be mitigated with ground improvement. 45 As such, MM GEO-1 would require implementation of recommendations from the Geotechnical Report pertaining to earthwork, site preparation, and foundation design in order to protect the proposed improvements from the effects of expansive soil and foundation support to control settlement of Building 1. Implementation of MM GEO-1 would reduce impacts associated with seismic-related ground failure and liquefaction to less than significant. 42 Forrest, T.M., Gildea, P., Flessas, M.G. 2020. Geotechnical Investigation, 10x Genomics Building 1, 1701 Springdale Avenue, Pleasanton California. December 3. 43 City of Pleasanton. 2009. Pleasanton General Plan 2005-2025, Chapter 5, Public Safety Element, Figure 5-4, Liquefaction Susceptibility Level. Website: https://www.cityofpleasantonca.gov/civicax/filebank/blobdload.aspx?BlobID=23899. Accessed February 2, 2021. 44 Parrish, John G. 2008. Special Publication 117A, Guidelines for Evaluating and Mitigating Seismic Hazards in California. September 11. Website: https://www.conservation.ca.gov/cgs/publications/sp117a. Accessed February 1, 2021. 45 Forrest, T.M., Gildea, P., Flessas, M.G. 2020. Geotechnical Investigation, 10x Genomics Building 1, 1701 Springdale Avenue, Pleasanton California. December 3.