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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 />3.0-56 <br />Vibration is a unique form of noise because its energy is carried through buildings, structures, and the ground, whereas noise is simply carried through the air. Thus, vibration is generally felt rather than heard. Some vibration effects can be caused by noise (e.g., the rattling of windows from <br />passing trucks). This phenomenon is caused by the coupling of the acoustic energy at frequencies <br />that are close to the resonant frequency of the material being vibrated. Typically, groundborne vibration generated by man-made activities attenuates rapidly as distance from the source of the vibration increases. The ground motion caused by vibration is measured as particle velocity in <br />inches per second and is referenced as vibration decibels (VdB) when evaluating impacts on <br />humans or as peak particle velocity when evaluating impacts on structures. <br />The vibration velocity level threshold of perception for humans is approximately 65 VdB. A vibration <br />velocity of 75 VdB is the approximate dividing line between barely perceptible and distinctly <br />perceptible levels for many people. Most perceptible indoor vibration is caused by sources inside <br />buildings such as the operation of mechanical equipment, movement of people, or slamming of doors. Typical outdoor sources of perceptible groundborne vibration are construction equipment, <br />steel-wheeled trains, and traffic on rough roads. <br />NOISE SETTING <br />The project site is on Bancroft Avenue between Estudillo Avenue and Joaquin Avenue. The land <br />uses in the project vicinity include single- and multi-family residential buildings, commercial <br />businesses, and a middle school. The dominant source of noise in the project area is traffic on <br />Estudillo Avenue and Bancroft Avenue. The existing (2015) and future (2035) noise levels in the city were estimated in the 2035 General Plan Draft Environmental Impact Report (DEIR) (San Leandro <br />2016b). The traffic noise contours in the DEIR for both 2015 and 2035 indicate that the 60 dBA <br />Community Noise Equivalent Level (CNEL) contours for Estudillo Avenue and Bancroft Avenue <br />extend into the project site. As part of the noise analysis for the DEIR, short-term (15-minute) and long-term (24-hour) noise measurements were taken in 2015. Table 3.12-1 summarizes the noise <br />measurements at the locations closest to the project site. <br />TABLE 3.12-1 <br />2015 NOISE MEASUREMENTS <br />Location Measurement Length Measured Level (dBA) <br />LT-1 East 14th Street and 143rd Avenue; 1.15 miles south of <br />the project site 24 hours 64.8 Ldn <br />LT-3 Alvarado Street; 819 feet northwest of Davis Street; <br />0.96 miles west of the project site a 24 hours 67.4 Ldn <br />ST-4 Bancroft Avenue and Dutton Avenue; 0.49 miles north of <br />the project site 15 minutes 65.6 Leq <br />ST-5 East 14th Street and Juana Avenue; 0.41 miles southwest <br />of the project site 15 minutes 65.6 Leq <br />Source: San Leandro 2016b <br />Note: a. The measurement at LT-3 included noise from the nearby BART tracks, which are not a significant source of noise at the project <br />site. <br />Noise-Sensitive Receptors <br />Noise-sensitive land uses are those that may be subject to stress and/or interference from excessive noise. Noise-sensitive land uses include residences, schools, hospitals, and institutional