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111 noise levels at the surrounding receptors. Permanent noise level from truck loading and unloading would be up to 1 dBA CNEL, assuming four truck deliveries per day; for all other existing receptors, the noise level increase would not be measurable or detectable (e.g., a 0 dBA CNEL increase). Because the center of the loading dock would be approximately 45 feet from to the nearest property line, the hourly average noise level at the property line would be 65 dBA Leq, which even assuming a minimum attenuation of 5 dBA for the building façade, would exceed the Zoning Code’s 55 dBA threshold at the property line. With respect to noise resulting from Commercial Component-generated traffic, Illingworth & Rodkin compared the existing plus project traffic scenario to the existing condition, based on peak hour turning movements for existing traffic volumes and for existing plus project traffic volumes at eight intersections in the vicinity of the project component site, as included in the traffic study. The Commercial Component’s contribution to the overall noise level increase was determined to be approximately 1 dBA CNEL at two roadway segments in the project vicinity and less along the other segments. Therefore, the Commercial Component would not result in a permanent noise increase of 3 dBA CNEL or more at noise-sensitive receptors in the property’s vicinity. Operational Noise Conclusion. The combined operational noise from project mechanical equipment, truck loading and unloading, and traffic would result in an increase of approximately 2 dBA CNEL or less at all existing noise- sensitive receptors in the project vicinity. As such, the proposed Commercial Component would not result in a substantial increase over ambient (continuous) noise levels in the project vicinity; but because operational activities could result in temporary noise levels potentially exceeding the Zoning Code limit of 55 dBA at the property line, due to emergency generator testing and truck loading and unloading activities, DTPP Plan-Wide Amendments SEIR Mitigation Measure NO-2 would apply to the Commercial Component. With completion of Mitigation Measure NO-2 (including City approval of the rooftop mechanical equipment and equipment screening design), and compliance with standard conditions of approval to implement the City’s Noise Ordinance and Noise Element, this Commercial Component will not expose persons to or generate excessive noise levels on a project or cumulative level (because other construction projects will also be subject to the noise control measures noted). The impact of this Commercial Component would be considered less than significant, and no additional mitigations would be required. Therefore, the Commercial Component would not create new impacts or increase impacts, and there is no new information of substantial importance for CEQA purposes. b. Regarding groundborne vibration and groundborne vibration noise levels, the DTPP program EIR (pp. 11-23 through 11-29) concluded that potentially significant temporary noise and vibration impacts could be generated by demolition and construction activities in the DTPP area. 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. These impacts were reduced to less than significant with mitigation. The DTPP Plan-Wide Amendments program SEIR (pp. 11-27 through 11-28) generally concurred with the DTPP conclusion with respect to DTPP development construction period groundborne vibration effects. It found the same types of construction activities would occur and the distances to the nearest receptor location would be similar, thereby posing similar level of potential impact. The Plan-Wide Amendments included Mitigation Measure NO-3 (“Vibration Reduction”), which restates Mitigation Measure 11-3 from the DTPP Final EIR with minor text revisions (“clarifying amendments”). Mitigation Measure NO-3 requires implementation of ground-borne vibration abatement measures, such as restriction of vibration-generating activity, notification of nearby occupants, consultation with the City regarding pre-drilling holes for pile driving, conducting a pre-construction site survey of historic structures within 200 feet of pile driving activities for City review, and monitoring pile-driving activities. The Illingworth & Rodkin noise study (p.35) determined, “Pile driving equipment utilizing impact or vibratory hammers, which can cause excessive vibration, is not expected to be required for the proposed project.” As noted above, the proposed Commercial Component would involve demolition and construction activities. DTPP EIR Mitigation Measures 11-3 and 11-4 would reduce these impacts to less-than-significant levels through scheduling, monitoring, and other planning and engineering measures. In addition, construction of the proposed Commercial Component would be required to comply with the City of Redwood City Noise Ordinance and all applicable City codes and regulations for noise control. Required implementation of a construction traffic plan (including the identification of truck haul routes) approved by the City would help minimize construction traffic-related impacts on adjacent land uses. These measures, which shall be required as conditions of Commercial Component approval, would reduce the temporary construction noise and vibration impacts of the Commercial Component to less-than-significant levels. ATTY/RESO.0028/CC RESO CEQA GUIDLINES (920 SHASTA) - EXHIBIT A REV: 04-22-25 VR Page 111 of 148