Appendix A Noise Study Report - Laserfiche WebLink

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• Land uses west of Fairview Street and south of the Santa Ana River include single-family and multifamily residences, a medical office, a park, a trail, and office uses that range from 2 ft higher to 5 ft lower in elevation than Fairview Street. • Land uses east of Fairview Street and north of the Santa Ana River include single- family residences and commercial and light industrial uses that range from 2 ft higher in elevation than Fairview Street to approximately the same elevation as Fairview Street. • Land uses west of Fairview Street and north of the Santa Ana River include single-family residences, vacant land, and commercial and light industrial uses that range from 2 ft higher to 9 ft lower in elevation than Fairview Street. Fifteen short-term noise level measurements were conducted at representative locations to document the existing noise environment. All short-term noise level measurements were used to calibrate the Federal Highway Administration (FHWA) Traffic Noise Model (TNM) 2.5 (2004) with concurrent traffic counts and observed vehicle speeds to ensure the accuracy of TNM 2.5. A total of 92 representative existing receptors were modeled and evaluated for potential noise impacts resulting from traffic noise. The results of the modeled noise levels for Existing, Future No Build, and Future Build conditions are provided in Table B.1 in Appendix B. Two long-term (24-hour) noise level measurements were conducted in the project area to characterize the change in hourly noise levels over the course of a 24-hour period in the project area and to identify the peak traffic noise hour. When traffic noise impacts have been identified, noise abatement measures must be considered. Traffic noise impacts result from one or more of the following occurrences: (1) an increase of 12 A -weighted decibels (dBA) or more over the corresponding existing noise levels, or (2) predicted noise levels approaching or exceeding the Noise Abatement Criteria (NAC). Implementation of the proposed Project would result in potential short-term noise impacts during construction and long-term operational noise impacts from use of the completed project. Of the 92 modeled receptors, nine receptors would approach or exceed the NAC. No modeled receptors would experience a substantial increase of 12 dBA or more over their corresponding modeled existing noise levels. Noise abatement measures were evaluated for receptors within the project limits that would be or would continue to be exposed to traffic noise levels approaching or Fairview Street Improvements from 9th Street to 16th Street and Bridge Replacement Project Noise Study Report