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Peer Review of Geotechnical and Geologic Hazard Investigations BSK Project G2300051 11991 Dublin Canyon Road (Hana Japan) September 6, 2024 Pleasanton, California Page 2 Canyon Road, Pleasanton, California” by Cotton, Shires & Associates, Inc, dated May 14, 2008 (Project No. R1120F). Scope of Services The objective of our peer review was to provide an independent assessment of the four pertinent documents that the City provided to evaluate whether the ENGEO reports and letter provide adequate and appropriate geotechnical and geological assessment of the site conditions for the proposed project. A certified engineering geologist of BSK also conducted a brief site visit to observe the site conditions. Our review did not include performing any additional subsurface investigation, laboratory testing, or engineering analyses, such as slope stability analysis, as part of our services. Site Reconnaissance A California registered Certified Engineering Geologist (CEG) from BSK visited 11991 Dublin Canyon Road in Pleasanton, California (Site) on August 16, 2024 to observe site conditions and look for evidence of pertinent geologic hazards, primarily slope instability and/or faulting. The slope along the southwest edge of the Site has a gradient ranging from about 2H:1V (horizontal to vertical) to 1¼H:1V. The steeper section is part of a small cut slope adjacent to the asphalt-paved driveway. Further upslope and west of the driveway, several leaning trees were observed, however, the existing chain link fence located immediately below the tree line and along this slope appears plumb and in good condition. The existing slope that parallels Dublin Canyon Road ranges from about 5 to 32 feet high with gradients ranging from approximately 1¾H:1V to 1½H:1V. A concrete V-ditch that follows the crest of this slope is filled with soil and vegetation and does not appear to be fully operational. Indications of poor site drainage were also observed along this slope. This includes an erosional gully immediately west and upslope of an underground electrical box and a shallow soil slump approximately 15 feet to the west of the erosional gully. In general, the Site slopes appear to be experiencing soil creep and minor, shallow soil slumps/erosion likely caused by poor drainage practices. Besides this, no other evidence of slope instability was observed. No evidence of surface faulting or fault-related features were observed at the Site. Review Comments The primary geotechnical concerns identified by the Geotechnical Report are the potential for the presence of expansive soils, perched groundwater conditions, potential seismic hazards, including fault rupture and seismically-induced landslide hazards, and excavatability of native rock. In order to address potential fault rupture and seismically induced landslide hazards, the Geotechnical Report recommended a minimum 50-foot building setback zone from the main trace of the Calaveras Fault located along the east edge of the Site and a minimum 25-foot building setback zone from a possible secondary mapped fault trace along the southwest edge of the Site.