75C - PH - BRISTOL EIR FROM WARNER TO ST. ANDREW

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Table 18 summarizes the noise levels at the fifteen typical locations evaluated along Bristol Street. The maximum one -hour equivalent noise levels for a 5.0- foot receptor are shown for several scenarios including: 1. Existing noise levels at the outdoor activity area (accounting for local attenuation by existing noise barriers); 2. Future design year noise levels without project implementation (no project alternative); and 3. Future design year noise levels with the three proposed alternatives, including mitigation in the form of a 6 -foot or 8 -foot barrier at the right -of -way. (Also included are the barrier heights necessary to provide a 5 dBA attenuation from the "no- mitigation" condition, and the height to break the line -of -sight between a 5.5 -foot receptor and a 11.5 - foot truck exhaust stack located at the equivalent source to barrier , distance). The locations that exceed the federal exterior noise criteria with at least one of the alternatives are discussed in further detail below. For all eight _ locations, the proposed Bristol Street right -of -way is 120 feet and the noise barrier is located 60 feet from the roadway centerline. All calculations assume level terrain, and typically address conditions located 6 feet from the front or back of the house (to represent activity areas). Measurement Site 1 was in the front yard of a single family dwelling located north of Santa Clara Avenue. All three alternatives propose to remove this dwelling. Measurement Site 2 was located adjacent to an outdoor activity area in an elementary school playground, 23 feet from the right -of -way. Alternatives 1, 2 and 3 assume that the existing 23 feet remains between the right -of -way and play area. As shown in Table 18, a 6 -foot barrier constructed at the right -of- - way will be adequate to reduce noise levels to acceptable levels. Measurement Site 3 was at a multi- family dwelling complex and a common recreational area south of Santa Clara Avenue. All three alternatives propose _ to remove this dwelling. rV -28 75C -163