NS-3092 - Zone Change for 1801 East Chestut Ave

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SANTA ANA REZONE PROJECT INITIAL STUDYIMITIGATED NEGATIVE DECLARATION The nearest noise-sensitive receptor is the single-family residential land use located south of the project site. The nearest facade of the single-family land use is located approximately 160 feet south of the nearest proposed parking areas.At this distance,with minimal shielding from an existing concrete wall, noise levels associated with daily parking lot activities would attenuate to approximately 47 dBA Leq. The calculation spreadsheet with detailed modeling assumptions is provided in Appendix D. Noise levels resulting from parking lot activities at the proposed project site would not exceed the City's exterior noise limit of 55 dBA Leq hourly average during daytime hours, and a noise limit of 50 dBA Leq hourly average during nighttime hours, for receiving residential land uses. Therefore, operational noise levels due to parking lot activities would not result in a substantial permanent increase in excess of any of the noise performance thresholds and would represent a less than significant impact. Operational/Mobile Source Noise Impacts Less than significant impact.A significant impact would occur if project-generated traffic would result in a substantial increase in ambient noise levels compared with those that would exist without the proposed project. Typically, a doubling of the Average Daily Traffic (ADT) hourly volumes on a roadway segment is required in order to result in an increase of 3 dBA in traffic noise levels, which, as discussed in the characteristics of noise discussion above, is the lowest change that can be perceptible to the human ear in outdoor environments. Therefore, for the purposes of this analysis, a doubling of the existing ADT volumes would result in a substantial permanent increase in traffic noise levels. Based on the traffic analysis prepared for the proposed project by Urban Crossroads,"the proposed project is anticipated to generate an addition of 876 trips per day with 37 AM peak-hour trips and 63 PM peak-hour trips. Because of the high level of residential development to the south of the project site, the existing ADT on this roadway segment would be substantially higher than the trips generated by this project.As such,these new net trips would not double existing average daily trips; therefore, the proposed project would not result in a substantial permanent increase in ambient noise levels from project-generated traffic trips and mobile source operational noise impacts would be less than significant. b) Generation of excessive groundborne vibration or groundborne noise levels? Less than significant impact.A significant impact would occur if the proposed project would generate groundborne vibration or groundborne noise levels in excess of established standards. The City has not established requirements regarding construction vibration impacts;therefore, for the purposes of this analysis, the FTA guidelines for vibration impacts are used to determine potential significant construction and operational-related vibration impacts.63 fiz Urban Crossroads,Inc.2025.Santa Ana Rezone Trip Generation Assessment July 23 3 Federal Transit Administration(FTA).2018.Transit Noise and Vibration Impact Assessment Manual.September. 82 Q(yQ�} FC S Ordinance No. N sy{#keFFovativassharepolnt. lshes/vuhllcatlom5iteJShared Do ..ntVF.hI!.ti.,s/CIlenr CPN-fN)/0327/0327W47/ESMND/03z7NM7 Sa tz Anz gexnne Prare4 ISMNO.daa Page 94 of 118