NS-3092 - Zone Change for 1801 East Chestut Ave

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SANTA ANA REZONE PROJECT INITIAL STUDYIMITIGATED NEGATIVE DECLARATION Based on the traffic analysis prepared for the proposed project,61 the project site driveway currently generates an average of 246 two-way trips per day, with 24 trips during the AM peak-hour and 20 trips during the PM peak-hour, Based on the air quality modeling performed for this project, construction of the proposed project would generate a maximum of 119 total trips per day during any phase of project construction; 104 of these trips would be truck haul trips. This equates to less than 15 total trips per hour over the course of a standard construction workday. Typically, an approximate doubling of traffic volumes is required to cause 3 dBA noise increases, which are considered barely noticeable. The proposed project's addition of less than 15 total trips per hour would not double existing hourly trips on roadway segments accessing the project site.As such, the proposed project's maximum daily construction trips would not result in noticeable (much less substantial) noise increases along surrounding roadways and this impact would be less than significant. Construction Equipment Noise Construction is completed in discrete steps, each of which has its own mix of equipment and, consequently, its own noise characteristics. These various sequential phases would change the character of the noise generated on the site and,therefore, the noise levels surrounding the site as construction progresses. Despite the variety in the type and size of construction equipment, similarities in the dominant noise sources and patterns of operation allow construction-related noise ranges to be categorized by work phase. Typical operating cycles for these types of construction equipment may involve 1 or 2 minutes of full power operation followed by 3 or 4 minutes at lower power settings. Impact equipment such as pile drivers is not being used during construction of the proposed project. The site preparation phase, which includes excavation and grading of the site, tends to generate the highest noise levels because the noisiest construction equipment is earthmoving equipment. Earthmoving equipment includes excavating machinery and compacting equipment, such as bulldozers, draglines, backhoes, front loaders, roller compactors, scrapers, and graders. Typical operating cycles for these types of construction equipment may involve 1 or 2 minutes of full power operation followed by 3 or 4 minutes at lower power settings. Construction of the project requires the use of graders, excavators, dozers, front end loaders, and backhoes. The maximum noise level generated by each bulldozer, excavator, and grader is assumed to be 85 dBA Lmax at 50 feet from this equipment.A characteristic of sound is that each doubling of sound sources with equal strength increases a sound level by 3 dBA.Assuming that each piece of construction equipment operates at some distance from the other equipment, a reasonable worst- case combined noise level during this phase of construction would be 90 dBA Lmax at a distance of 50 feet from the acoustic center of a construction area. This would result in a reasonable worst-case hourly average of 86 dBA Uq. The closest noise-sensitive receptors to the project site are single-family residences located south of the project site. The closest residence would be located approximately 160 feet from the acoustic 61 Urban Crossroads, Inc.2025.Santa Ana Rezone Trip Generation Assessment.July 23. 80 qn6 FCS Ordinance No. N44=ytr�4e ,r tions.sharepoint,am/sites/Puhlisationssite/Sh.red oocumentsfPc6llcxt,ansl[Iient(Prvdw]/on271o327W471hSMND/o3z7Doa7 Santa Ana Rezon,Project ISMNO.aocr Page 92 of 118