Laserfiche WebLink
• <br /> • <br /> Draft Supplemental Environmental Impact Report Page IV.0-1 • <br /> Forward Inc. Landfill 2018 Expansion Project • <br /> C. NOISE • <br /> This section describes the existing and likely future noise environments in the vicinity of the proposed • <br /> Forward Landfill Expansion project to take into account the proposed changes to the project described • <br /> in this Supplemental EIR. It also addresses the project's conformity with the San Joaquin County • <br /> General Plan and Noise Ordinance. The impacts and mitigations in this section replace those in Section • <br /> IV.0 of the 2013 EIR. • <br /> Settin¢ • <br /> • <br /> Background • <br /> To describe noise environments and to assess impacts on noise-sensitive areas, a frequency weighting • <br /> measure, which simulates human perception, is commonly used. It has been found that A-weighting • <br /> of sound levels best reflects the human ear's reduced sensitivity to low frequencies, and correlates well • <br /> with human perceptions of the annoying aspects of noise. The A-weighted decibel scale (dBA)' is cited • <br /> in most noise criteria. Decibels are logarithmic units that conveniently compare the wide range of <br /> sound intensities to which the human ear is sensitive. Table IV.0-1 identifies typical ranges of decibel • <br /> levels for common sounds heard in the environment. • <br /> Table IV.0-1:Typical Noise Levels <br /> Noise Level(dBA) Outdoor Activity Indoor Activity • <br /> 90+ Gas lawn mower at 3 feet,jet flyover Rock Band • <br /> at 1,000 feet • <br /> 80-90 Diesel truck at 50 feet Loud television at 3 feet • <br /> 70-80 Gas lawn mower at 100 feet, noisy Garbage disposal at 3 feet,vacuum • <br /> urban area cleaner at 10 feet • <br /> 60-70 Commercial area Normal speech at 3 feet • <br /> • <br /> 40-60 Quiet urban daytime, traffic at 300 Large business office,dishwasher • <br /> feet next room <br /> 20-40 Quiet rural, suburban nighttime httime Concert hall (background), library, • <br /> g bedroom at night • <br /> 10-20 Broadcast / recording studio <br /> • <br /> 0 Lowest threshold of human hearing Lowest threshold of human hearing • <br /> Source:(modified from Caltrans Technical Noise Supplement,1998) • <br /> • <br /> • <br /> A decibel (dB) is a unit of sound energy intensity. Sound waves, traveling outward from a source, exert a sound pressure level • <br /> (commonly called "sound level") measured in dB. An A—weighted decibel (dBA)is a decibel corrected for the variation in frequency • <br /> response to the typical human ear at commonly encountered noise levels. <br /> • <br /> • <br /> • <br /> • <br />