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POTENTIALLY POTENTIALLY SIGNIFICANT LESS THAN ISSUES NO SIGNIFICANT UNLESS SIGNIFICANT IMPACT ISSUES MITIGATION IMPACT INCORPORATED SOURCES e. Have soils incapable of adequately supporting the use X of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water? EXPLANATION: a) i. A soils report was prepared for the proposed project by Terrasearch, Inc. (May 11, 2009). The subject site is located within the Coast Ranges geomorphic province and consists of a belt of sedimentary, volcanic, and metamorphic rocks, which extend• from southern California to Oregon. The site is west of the Hayward Fault Zone and is not located within any California Geological Survey (CGS) hazard zone with respect to fault rupture or landsliding. However, the site is located in an area zoned for Iiquefaction hazard, according to the CGS Seismic Hazard Zone map for the San Leandro Quadrangle. The nearest active fault to the project is the Hayward fault, approximately 1.4 miles to the northeast; the Calaveras, approximately 10 miles to the northeast; and the San Andreas, approximately 16.7 miles to the southwest, within the subject property. ii, iii. During a major earthquake on a segment of one of the nearby faults, strong ground shaking is expected to occur at the project site. Ground shaking is a complex concept related to velocity, amplitude and duration of earthquake vibrations. Damage from ground shaking is caused by the transmission of earthquake vibrations from the ground to the structure. The most destructive effects of an earthquake are usually seen where the ground is unstable and structures are poorly designed and constructed. In 2002, the U.S. Geologic Survey (USGS) predicted a 62 percent probability of a magnitude 6.7 or greater earthquake occurring in the San Francisco Bay Area by the year 2032. The project site is also within a designated liquefaction hazard zone. Strong shaking during an earthquake can result in ground failure such as that associated with soil liquefaction, lateral spreading and cyclic densification. Due to the nature of the subsurface materials, the site is susceptible to liquefaction, differential seismically- induced settlement and/or ground lurching. The site will experience strong ground shaking associated with a large earthquake on the Hayward, Calaveras, and/or San Andreas Faults. Based on recent geological studies in the area, potentially significant geologic impacts could occur on the project site, therefore, mitigation of potential liquefaction hazards is required with project implementation. Mitigation Measure #11: The City of San Leandro has incorporated the 2009 International Building Code into its municipal building code (Title 7, Chapter 7 -5). The project applicant would be required to comply with all applicable State and City regulations to address potential geologic hazards associated with the proposed project, including ground shaking and liquefaction. Geotechnical and seismic design criteria must conform to engincering recommendations in accordance with the seismic requirements of the 2009 California Building Code (Title 24) and any amendments adopted in the San Leandro Municipal Code. Additionally, because the project site is in a liquefaction Seismic Hazard Zone, the project applicant will be required to comply with the guidelines set forth by California Geological Survey Special Publication 117. iv. The project site is nearly flat, and there are no hilly areas immediately adjacent to the project site. The site is at an elevation of approximately 52 feet above mean sea level (AMSL). The topographic gradient is southwest towards San Francisco Bay. The site consists of a previously developed parcel that was paved over in 1965 with an asphalt parking lot and a 43,200 square foot commercial office building. The site is underlain by alluvium consisting of interbedded clay, sand and gravel. The site is not associated with significant slopes, and there are no adjacent hillsides. Therefore, the proposed project would not create potential impacts associated with landslides, mudflows or other mass soil movements. b) The proposed project would consist of grading and trenching activities that could create effects on water quality as a result of erosion. Because the project site exceeds one acre in size, the project applicant would be required to apply for coverage under the State General Construction Permit in order to comply with federal National Pollutant Discharge Elimination System (NPDES) requirements, in accordance with the State Water Resources Control Board (see Section VIII, Hydrology and Water Quality). The applicant would be required to develop and implement a Storm Water Prevention Plan ( SWPPP) to reduce potential erosion and subsequent sedimentation of storm water runoff. The SWPPP would include Best Management Practices (BMPs) to control erosion associated with grading, trenching and other ground surface disturbance. Additionally, all construction activities will be required to comply with Chapter 18 of the San 2450 Washington Avenue Apartments 9 October 2011