5A Public Hearings 2018 0507 - Laserfiche WebLink

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City of San Leandro Alvarado Commerce Center Project 66 have noise levels in the range of 40 to 50 dBA, while arterial streets are in the 50 to 60+ dBA range. Normal conversational levels are in the 60 to 65 dBA range, and ambient noise levels greater than 65 dBA can interrupt conversations. Noise levels typically attenuate (or drop off) at a rate of 6 dBA per doubling of distance from point sources (such as construction equipment). Noise from lightly traveled roads typically attenuates at a rate of about 4.5 dBA per doubling of distance. Noise from heavily traveled roads typically attenuates at about 3 dBA per doubling of distance. Noise levels may also be reduced by the introduction of intervening structures. For example, a single row of buildings between the receptor and the noise source reduces the noise level by about 5 dBA, while a solid wall or berm that breaks the line-of-sight reduces noise levels by 5 to 10 dBA. The construction style for dwelling units in California generally provides a reduction of exterior-to-interior noise levels of about 30 dBA with closed windows (Federal Highway Administration [FHWA] 2006). Some land uses are more sensitive to ambient noise levels than other uses due to the amount of noise exposure and the types of activities involved. For example, residences, motels, hotels, schools, libraries, churches, nursing homes, auditoriums, museums, cultural facilities, parks, and outdoor recreation areas are more sensitive to noise than commercial and industrial land uses. The nearest sensitive receptor to the project site is Lincoln High School, approximately 1,300 feet (0.25 mile) to the east. The nearest residences to the project site are located approximately 1,500 feet (0.28 mile) to the northeast of the property line. Sight-lines to project site from these two sensitive receptors are blocked by existing industrial buildings and intervening sound walls. Existing Setting The noise environment on the project site is dominated by the industrial uses on and surrounding the site, vehicle noise generated from I-880, which accommodates 10 lanes of vehicle traffic in the project vicinity, vehicle noise from Alvarado Street and Aladdin Avenue, and rail vehicle noise from the nearby Union Pacific Railroad tracks and Bay Area Rapid Transit (BART) tracks. Noise regulations and ordinances typically establish allowable noise levels for different land uses and define exempt noise activities. The San Leandro Land Use Compatibility Guidelines included in the San Leandro General Plan Environmental Hazards Element identify normally acceptable noise levels in industrial areas as up to 75 decibels. Noise levels from 70 to 80 decibels are conditionally acceptable and noise levels in excess of 75 decibels are normally unacceptable. Chapter 4-1 of the SLMC provides provision for restrictions and regulations for noise in the city of San Leandro. These regulations specifically restrict construction activities that occur after the typical work day for uses adjacent to or across a street or right-of-way from a residential use (SLMC Section 4-1-1115). However, the SLMC does not include restrictions on construction activities in industrial areas. Roadway Noise Noise levels associated with existing and future traffic along area roadways were estimated by completing a screening analysis for project-generated traffic. Existing A.M. and P.M. peak hour traffic volumes were compared with the expected peak hour traffic volume increases after construction of the project using traffic volumes provided in the Transportation Impact Study Report conducted by TJKM in June 2017 (Appendix D). Peak hour traffic volumes were used in this analysis because they represent the busiest traffic conditions. As the specific future use of the project is unknown, the analysis included both warehouse and advanced manufacturing for the occupying 363