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<br /> <br />ͭͲͱͱʹ-ͬͰ Noise Memo.docx ͭͮ Warner Avenue Footlab <br />CONSTRUCTION NOISE LEVELS <br />The FTA Transit Noise and Vibration Impact Assessment Manual recognizes that construction projects <br />are accomplished in several different stages and outlines the procedures for assessing noise impacts <br />during construction. Each stage has a specific equipment mix, depending on the work to be <br />completed during that stage. As a result of the equipment mix, each stage has its own noise <br />characteristics; some stages have higher continuous noise levels than others, and some have higher <br />impact noise levels than others. The Project construction activities are expected to occur in the <br />following stages: <br />o Demolition <br />o Grading <br />o Site Preparation <br />o Building Construction <br />o Architectural Coating <br />o Paving <br />CONSTRUCTION REFERENCE NOISE LEVELS <br />To describe construction noise activities, this construction noise analysis was prepared using <br />reference construction equipment noise levels from the Federal Highway Administration (FHWA) <br />published the Roadway Construction Noise Model (RCNM), which includes a national database of <br />construction equipment reference noise emission levels. (ͱ) The RCNM equipment database <br />provides a comprehensive list of the noise-generating characteristics of specific types of <br />construction equipment. In addition, the database provides an acoustical usage factor to estimate <br />the fraction of time each piece of construction equipment is operating at full power (i.e., its loudest <br />condition) during a construction operation. According to the EPA, FTA, and FHWA, the overall <br />construction noise level is governed primarily by the noisiest pieces of equipment. The quieter pieces <br />do not affect the overall level, but they do reduce the magnitude of the fluctuations in the noise level. <br />Therefore, a rough estimate of the noise level need only include the noisiest pieces of equipment <br />expected at the site. (Ͳ) (Ͱ) (ͳ) Consistent with FHWA and FTA guidance for detailed construction <br />noise assessment, Table ͱ presents the combined noise levels for the loudest construction activities <br />expected for each stage, assuming all equipment operates simultaneously. <br />CONSTRUCTION NOISE ANALYSIS <br />Construction projects involve various stages, and activities frequently shift from one location to <br />another. For example, during site preparation and grading, noise-generating activities may <br />concentrate in an area for a short period to remove an obstruction, while the majority of the grading <br />involves the equipment moving back and forth in a predictable pattern throughout the site; building <br />construction and foundation work generally concentrate near the building footprint, while paving <br />generally involves a predictable pattern of movement throughout the site. Therefore, construction <br />activities are best evaluated as multiple moving point sources within the construction area since the <br />speed and power of the equipment vary, and the equipment constantly changes position in terms of <br />its distance and direction relative to the receivers. (Ͱ) (ʹ) Using the reference construction <br />equipment noise levels and the CadnaA noise prediction model, calculations of the Project <br />construction noise level impacts by phase at the nearby sensitive receiver locations were completed. <br />