AgdaPkt 2017-09-11 Closed and Joint SA PFA

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TA. - Page 95 LSA ASSOCIATES, INC. ROCKETSHIP REDWOOD CITY ELEMENTARY SCHOOL PROJECT SEPTEMBER 2016 INITIAL STUDY/MITIGATED NEGATIVE DECLARATION a) Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies?(Less-Than- Significant Impact) The City of Redwood City sets noise standards in the Redwood City General Plan and noise ordinance of the Municipal Code. The City's General Plan Safety Element identifies exterior noise thresholds up to 65 dBA 97 CNEL98 as conditionally acceptable for school land uses,while exterior noise levels between 65 dBA and 70 dBA CNEL are considered normally unacceptable for such land uses. Although a portion of the project site is located within San Mateo County,the County does not have adopted regulations that establish land use compatibility standards or criteria for evaluating land use projects;therefore,the City's noise standards are applicable to the proposed project. The City of Redwood City regulates noise in the City's Municipal Code. Section 24.30 through 24.34, Excessive and Unreasonable Noises apply to construction noise. This ordinance limits construction and demolition activities to the hours of 7:00 a.m. to 8:00 p.m. on weekdays. Construction and demolition activities are not permitted on weekends. The ordinance also limits noise levels generated by an individual item of equipment to no more than 110 dB (decibels)99 measured within a residential district of the City at any distance of 25 feet from the equipment. Any construction site within 500 feet of a residential area must post a sign at all entrances to the work site prior to commencement of the work for the purpose of informing all contractors and subcontractors and all other persons at the property of the basic limitations upon noise and construction activities provided in the noise ordinance. Section 24.2 1,Prohibited Noise Levels in Residential Districts limits noise between the hours of 8:00 p.m. and 8:00 a.m. to no more than 6 dB above the local ambient measured noise level within a residential district. The San Mateo County Code of Ordinances indicates that construction noise is exempted from noise standards and is permissible between the hours of 7:00 a.m. to 6:00 p.m. on weekdays,and 9:00 a.m. to 5:00 p.m. on Saturdays. Construction is prohibited on Sundays,Thanksgiving,and Christmas. Project Land Use Compatibility.Existing sources of noise within the project vicinity include noise generated by industrial uses and roadway noise.However,roadway noise is the predominant source of noise. The roadway noise contours for Redwood City indicate that traffic noise levels on the project site range between 55 and 60 dBA,100 which is considered conditionally acceptable for new school projects.Noise levels on the project site would be highest adjacent to Bay Road,while noise levels in the middle of the site and those areas closest to Charter Street would be less than 60 dBA. The existing building is set back approximately 75 feet from Bay Road,resulting in ambient noise 97 dBA is the sound level obtained by use of A-weighting.The A-weighting filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the frequency response of the human ear and correlates well with subjective reactions to noise.All sound levels in this report are A-weighted,unless reported otherwise. 98 CNEL us the Community Noise Equivalent Level—the 24-hour A-weighted average sound level from midnight to midnight,obtained after the addition of 5 decibels to sound levels occurring in the evening from 7:00 p.m.to 10:00 p.m.and after the addition of 10 decibels to sound levels occurring in the night between 10:00 p.m.and 7:00 a.m. 99A unit of level that denotes the ratio between two quantities proportional to power;the number of decibels is 10 times the logarithm(to the base 10)of this ratio. 100 Redwood City,City of,2010.Redwood City General Plan-Public Safety Element,Figure PS-12. P:1RWC1401B Rocketship Schwl\PRODUCrSUS-MNDT&Iic\Ra kets*Public Review 09-29-16.do (09/29/16)PUBLIC REVIEW DRAFT 71 ATTY/RESO.0084/CC RESO ADOPTING CEQA-ROCKETSHIP CHARTER SCHOOL APPEAL REV:09-05-17 VR Page 79 of 124