AgdaPkt 2014-10-06 Closed and Joint with SA

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7.3.B. - Page 72 Summary of Impacts Potentia'ly Less than Significant Less than Significant With Mitigation Significant No Impact Incorporated Impact Impact in the project vicinity above levels existing without the project? e) For a project located within an airport land use plan or, where such a plan has X not been adopted, within two miles of a public airport or public use airport, expose people residing or working in the project area to excessive noise levels? f) For a project within the vicinity of a private airstrip, expose people residing or X working in the project area to excessive noise levels? Documentation: a., b., & d. Noise in Redwood City is regulated by the City's Noise Ordinance (Chapter 24 of the Municipal Code). In addition, the Noise Element of the City's General Plan enumerates noise policies. More specifically, excessive and unreasonable noise levels are defined as noise levels generated by construction activities, including demolition, alteration, repair or remodeling of existing structures, and construction of new structures, on property within the City, at more than 110 decibels (dB) measured at any point within a residential district of the City and outside of the plane of the property. Therefore, construction noise is required to be less than 110 dB within residential districts or within 500 feet of a residential district in the City, and no construction noise is permitted between the hours of 8:00 PM and 7 :00 AM the following day. The General Plan requires all exterior noise sources (construction operations, air compressors, pumps, fans, and leaf blowers) to use available noise suppression devices and techniques to bring exterior noise down to acceptable levels compatible with adjacent land uses. The primary sources of noise from the project would be temporary construction noise and operational noise. Construction noise is largely a function of the construction equipment used, the location and sensitivity of nearby land uses, and the timing and duration of the noise - generating activities. Construction noise levels would vary depending on construction phase, equipment type and duration of use, distance between noise source and receptor, and presence or absence of barriers between noise source and receptor. All noise - generating construction activities are anticipated to be conducted on weekdays between the hours of 7:00 AM and 8:00 PM in accordance with City requirements. The DTPP program EIR (p. 11 -20) concluded that new DTPP facilitated multifamily residential development could be exposed to noise levels exceeding City guidelines and State Title 24 standards, resulting in a potentially significant impact. Mitigation 11 -1 states that a noise study consistent with the requirements of the California Building Code shall be conducted for new multifamily residential projects, and noise reduction measures necessary to achieve compatibility with the City's Noise Element guidelines (55 dBA CNEL at sensitive exterior spaces) and Title 24 standards (45 dBA CNEL within residential units) shall be incorporated into the project. This measure, which shall be required as a condition of approval for the project, would reduce the potential noise impacts on the project to a less- than - significant level. The DTPP program EIR (p. 11 -22) also identified potentially significant intermittent vibration impacts for residential projects located within 100 feet of the centerline of the Caltrain railroad tracks. The proposed project site is located adjacent to the Caltrain tracks right -of -way. Therefore, Mitigation 11 -2 shall be required as a condition of approval for the project and would reduce the potential ground -borne vibration impacts on the project to a less -than significant level. The mitigation requires a detailed, site - specific vibration study that demonstrates that ground -borne vibrations associated with rail operations either: (1) would not exceed applicable Federal Transit Administration (FTA) ground -borne vibration impact assessment criteria (see Table 11.6 of the DTPP program EIR), or (2) can be reduced to below the applicable FTA criteria thresholds through building design and construction measures (e.g., stiffened floors, modified foundations). c. The DTPP program EIR (p. 11 -29) concluded that noise levels from DTPP development would increase primarily due to new traffic patterns, new commercial development next to or below residential development, and site - specific sources such as mechanical equipment. Traffic noise increases resulting from DTPP development are projected to be from less than 1 dB to up to 2 dB; these increases are considered less than significant because they are imperceptible to the average human ear within the existing Downtown environment. (EIR pp. 11 -19, 11 -29, and 11- 30) Other sources of noise (commercial operations, mechanical equipment) are subject to the City of Redwood City 23