Appendix A Noise Study Report - Laserfiche WebLink

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Chapter 4. Federal, State, and Local Policies and Procedures ........................................................................... 4.1.2. Traffic Noise Analysis Protocol for New Highway Construction and Reconstruction Projects The Caltrans Protocol specifies the policies, procedures, and practices to be used by agencies that sponsor new construction or reconstruction of federal or federal -aid highway projects. The NAC specified in the Protocol are the same as those specified in 23 CFR 772. The Protocol defines a noise increase as "substantial" when the predicted noise levels under build conditions exceed existing noise levels by 12 dBA. The Protocol also states that a sound level is considered to approach an NAC level when the sound level is within 1 dB of the NAC identified in 23 CFR 772 (e.g., 66 dBA is considered to approach the NAC of 67 dBA, but 65 dBA is not). The Caltrans TeNS (September 2013) and the Protocol provide detailed technical guidance for the evaluation of highway traffic noise. This includes field measurement methods, noise modeling methods, and report preparation guidance. 4.2. State Regulations and Policies 4.2.1. California Environmental Quality Act Noise analysis under CEQA may be required regardless of whether the proposed Project is a Type 1 project. The CEQA noise analysis is completely independent of the 23 CFR 772 analysis done for NEPA. Under CEQA, the baseline noise level is compared to the build noise level. The assessment entails looking at the existing setting and how large or perceptible any noise increase would be in a given area. Key considerations include the uniqueness of the setting, the sensitive nature of the noise receptors, the magnitude of the noise increase, the number of residences affected, and the absolute noise level. The significance of noise impacts under CEQA are addressed in the environmental document rather than in the NSR. Even though the NSR (or noise technical memorandum) does not specifically evaluate the significance of noise impacts under CEQA, it must contain the technical information that is needed to make that determination in the environmental document. 4.2.2. Section 216 of the California Streets and Highways Code Section 216 of the California Streets and Highways Code relates to the noise effects of a proposed freeway project on public and private elementary and secondary schools. Under this code, a noise impact occurs if, as a result of a proposed freeway project, noise levels exceed 52 dBA Leq(h) in the interior of public or private elementary or secondary school classrooms, libraries, multipurpose rooms, or spaces. Fairview Street Improvements from 9th Street to 16th Street 19 and Bridge Replacement Project Noise Study Report