Laserfiche WebLink
large pumps,horizontal directional drilling, and compressors. Random vibration can result from jackhammers, <br /> pavement breakers, and heavy construction equipment. Table 4.4-2 describes the general human response to <br /> different levels of groundborne vibration-velocity levels. <br /> Table 4.4-2 <br /> Human Response to Groundborne Vibration Levels <br /> Vibration Velocity(VdB) Human Response <br /> 65 Approximate threshold of perception for many humans. <br /> 75 Approximate dividing line between barely perceptible and distinctly perceptible. <br /> 85 Vibration acceptable only if there are an infrequent number of events per day. <br /> VdB=vibration decibels <br /> Source:FTA 2006 <br /> EXISTING NOISE CONDITIONS <br /> Existing Sensitive Land Uses <br /> Noise-sensitive land uses generally are those uses where exposure to noise would result in adverse effects, as well <br /> as uses where quiet is an essential element of their intended purpose. Residential dwellings are of primary concern <br /> because of the potential for increased and prolonged exposure of individuals to both interior and exterior noise <br /> levels.Adverse effects include speech interference, sleep interference, annoyance, and, in the extreme,hearing <br /> damage. Other noise-sensitive land uses are schools,hospitals, convalescent facilities,parks,hotels,places of <br /> worship, libraries, and other uses where low interior noise levels are essential. <br /> Existing noise-sensitive land uses in the project area consist primarily of residential dwellings adjacent to the <br /> roadways where pipelines for the collection system would be installed. The nearest residences to the Manteca <br /> Wastewater Quality Control Facility(WQCF) are residences along Yosemite Avenue, approximately 650 feet <br /> from the facility. There are residential communities or groups of residences adjacent to the following proposed <br /> collection system roadway segments: West Center St,west of Union Road; Lathrop Road, east and west of State <br /> Route(SR)99; Lathrop Road,west of Airport Way;the Union Pacific Railroad(UPRR)right-of-way intersection <br /> with Airport Way; and Manteca Road, south of Woodward Avenue. There are also scattered residences adjacent <br /> to many other segments of the proposed collection system. <br /> Vibration-sensitive land uses include those described above as noise sensitive; schools are considered less <br /> vibration sensitive than residences and similar land uses where people sleep. Vibration-sensitive land uses also <br /> include educational, commercial, and industrial buildings where vibration would interfere with operations within <br /> the building, including levels that may be well below those associated with human annoyance. Equipment such as <br /> electron microscopes and high-resolution lithographic equipment can be very sensitive to vibration, and even <br /> normal optical microscopes will sometimes be difficult to use when vibration is well below the human annoyance <br /> level. Manufacturing of computer chips is an example of a vibration-sensitive process. This category does not <br /> include most computer installations or telephone switching equipment because most such equipment is designed <br /> to operate in typical building environments where the equipment may experience occasional shock from bumping <br /> and continuous background vibration caused by other equipment(FTA 2006). The vibration-sensitive receptors in <br /> the project area are the same residences that are considered noise sensitive. <br /> Existing Sources <br /> Existing noise conditions in the project are influenced primarily by surface transportation noise emanating from <br /> vehicular traffic on the nearby area roadways(e.g., SR 120 and West Yosemite Avenue). At receptors adjacent to <br /> EDAW Manteca WQCF and Collection System Master Plans EIR <br /> Noise 4.4-6 City of Manteca <br />