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09/09/2013 <br /> Impact: Impact 15-2: Excavation Instabilities Caused by High Groundwater. <br /> Groundwater encountered during construction of the proposed projecYs below- <br /> grade installations could destabilize excavation walls, reduce the bearing <br /> capacity of in-place soils that might otherwise be suitable for foundation support, <br /> and exert additional stresses on basement walls and floor slabs. <br /> Mitigation: Mitigation 15-2. The detailed, design-level geotechnical investigations <br /> recommended under Mitigation 15-1 for each project construction phase shall <br /> fully characterize groundwater conditions on the development site and make <br /> appropriate recommendations regarding dewatering techniques, slope and <br /> shoring requirements for excavations, stabilization or replacement of saturated <br /> foundation materials, and hydrostatic pressure implications for the design of <br /> below-grade structures. <br /> Finding: Implementation of Mitigation 15-2 would reduce these potential groundwater <br /> impacts to a less-than-significant level. <br /> Facts in Support of Finding: Implementation of Mitigation 15-2 would reduce potential high <br /> groundwater impacts to a less-than-significant level by requiring detailed, site- <br /> specific geotechnical investigations and solutions prepared by a registered <br /> engineering geologist or geotechnical engineer, with review and approval <br /> authority by the City Engineer. These facts are described in Draft EIR chapter 15 <br /> (Geology and Soils) on pages 15-1 through 15-15, which is hereby incorporated <br /> by reference. <br /> Impact: Impact 15-3: Soil Erosion. Project development would disturb the site's existing <br /> cover of buildings, pavements and landscaping, potentially leaving soils exposed <br /> to wind and water erosion during the construction period. Eroded soils would be <br /> washed into on-site drainage facilities that discharge to the Bayfront Canal and <br /> San Francisco Bay. Deposition of these soils through natural sedimentation could <br /> adversely affect the carrying capacity of drain lines, pumping equipment and <br /> open channels, increasing flooding potential and maintenance requirements. In <br /> addition, suspended sediment would degrade water quality in the canal and in <br /> the bay by increasing turbidity levels. <br /> Mitigation: Mitigation 15-3. The applicant shall develop an erosion control plan in <br /> accordance with the provisions of the project's City-approved Stormwater <br /> Pollution Prevention Plan (SWPPP). The erosion control plan would be <br /> implemented throughout project construction, and would include measures for <br /> the post-construction stabilization of all disturbed ground. <br /> Finding: Implementation of Mitigation 15-3 would reduce these potential soil erosion <br /> impacts to a less-than-significant level. <br /> Facts in Support of Finding: Implementation of Mitigation 15-3 would reduce potential soil <br /> erosion impacts to a less-than-significant level by requiring detailed, site-specific <br /> geotechnical investigations and solutions prepared by a registered engineering <br /> geologist or geotechnical engineer, with review and approval authority by the City <br /> Engineer. These facts are described in Draft EIR chapter 15 (Geology and Soils) <br /> on pages 15-1 through 15-15, which is hereby incorporated by reference. <br /> ATTY/RES0.2901/STANFORD EIR CERTIFICATION RESO.#15294 <br /> REV:09-10-13 VR MUFF#100 <br /> Page 18 of 55 <br />