Agenda - Council - 06/13/2017 - Laserfiche WebLink

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Table 3 Nighttime Peak -Hour Highway Noise Modeling Noise Impact Results - May 5, 2017 Riverstone Addition, Ramsey, MN Receptor Lio (dBA) L50 (dBA R 1 61.9 57.8 R1A 62.7 58.7 R1B 61.9 58.1 R2 59.6 55.7 R3 57.4 53.8 R4 56.4 53.1 R5 56.3 52.7 R6 56.0 52.6 R7 56.5 53.2 R8 58.9 55.2 R9 57.9 54.4 R10 54.8 51.8 R 11 59.4 56.0 R12 59.0 55.6 R13 56.9 53.7 R14 56.4 53.3 R15 54.8 51.8 R16 55.1 52.0 R17 52.4 49.6 'Bolded numbers exceed Minnesota NAC-1 standards for nighttime hours. The modeled noise level at one of the 19 receptor locations exceeds the Minnesota NAC-1 standards for daytime hours. The modeled noise level at all but one of the receptor locations exceeds the Minnesota NAC-1 standards for nighttime hours. The NAC-1 daytime standards are designed to prevent speech interference in areas for outdoor activities. Areas for outdoor activities are not allowed if these noise levels are exceeded. The modeled L50 noise level at Receptor R1A exceeds the State standard by just 0.4 dBA. Remedies could include 1) having no areas for outdoor use in the portion of the property facing the roadway, 2)a barrier (solid fence) around all or a portion of the yard or patio at this home blocking the line of site between the vehicles on the road and an area designated for outdoor use or, 3) extending the proposed berm to provide additional mitigation at this location. The nighttime NAC-1 standards are designed to prevent sleep interference for people sleeping in bedrooms with partially open windows. NAC-2 nighttime standards apply to NAC-1 locations if the building is constructed in such a way that the exterior to interior sound level attenuation is at least 30 dBA and the building has year-round climate control. Buildings meeting the State building code requirements typically meet the 30 dBA exterior to interior sound level attenuation requirement.