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3.0 ENVIRONMENTAL CHECKLIST <br />1388 Bancroft Avenue Project City of San Leandro <br />Initial Study/Mitigated Negative Declaration November 2018 <br />3.0-60 <br />Impact Conclusion <br />The project would not result in exposure of persons to, or the generation of, noise levels in excess of standards established in the local general plan or noise ordinance, or applicable <br />standards of other agencies, or result in a substantial permanent increase in ambient noise <br />levels in the project vicinity above levels existing without the project. The impact would be less than significant. <br />b) Less Than Significant Impact with Mitigation Incorporated. <br />Operational Groundborne Vibration <br />Long-term operation of project would include occupation of residential units and a <br />parking lot. This would be consistent with planned use and existing surrounding uses and would not be a substantial source of groundborne vibrations or groundborne noise. <br />Construction Groundborne Vibrations <br />Construction activities would require the use of off-road equipment such as bulldozers, <br />excavators, graders, pavers, and vibratory compactors. The use of major groundborne vibration–generating construction equipment, such as pile drivers, would not be needed for <br />the project. Nonetheless, during construction, groundborne vibration may be generated as <br />a result of heavy equipment operations. This impact would be temporary, and vibration would cease completely when construction ends. <br />High levels of groundborne vibration can cause architectural or structural damage to <br />nearby buildings. The threshold at which there is a risk of architectural damage to normal <br />dwelling structures (i.e., cracks in plastered walls and ceilings) is a peak particle velocity of 0.2 inches per seconds (Caltrans 2013). Table 3.12-2 shows vibration levels for typical construction equipment, based on the application of the Caltrans-recommended <br />standard. <br />TABLE 3.12-2 <br />TYPICAL CONSTRUCTION EQUIPMENT VIBRATION LEVELS <br />Equipment Peak Particle Velocity at 25 Feet <br />(inches per second) <br />Vibratory Roller 0.210 <br />Large Bulldozer 0.089 <br />Loaded Truck 0.076 <br />Jackhammer 0.035 <br />Small Bulldozer/Tractor 0.004 <br />Source: FTA 2006; Caltrans 2013 <br />As shown in Table 3.12-2, operation of a large vibratory roller could produce vibrations as <br />high as 0.210 peak particle velocity inches per seconds and potentially cause architectural <br />damage to structures at 25 feet. The closest existing structure to the project site is approximately 10 feet away, and compaction of soil, gravel, or asphalt may be required near adjacent structures. Mitigation measure MM NOI-1 would require vibratory rollers to