6.9. SR 09-06-2011 - Laserfiche WebLink

Home Browse Search

ii 24. Odors, noise and dust. Will the project generate odors, noise or dust during construction or during operation? ®Yes ^ No If yes, describe sources, characteristics, duration, quantities or intensity and any proposed measures to mitigate adverse impacts. Also identify locations of nearby sensitive receptors and estimate impacts on them. Discuss potential impacts on human health or quality of life. (Note: fugitive dust generated by operations maybe discussed at item 23 instead of here.) AUAR Guidance: Dust, odors, and construction noise need not be addressed. Traffic- related noise is included in the analysis along with a dust and noise mitigation plan. Construction Noise Noise will be generated during construction of the project by construction equipment. Construction noise will be a temporary impact and maybe controlled by limiting construction activities to daytime hours in accordance with City ordinances and assuring that construction equipment is properly muffled. Traffic-Related Noise Federal and state standards have been developed for maximum sound levels in residential and commercial areas. By comparing existing and estimated future sound levels to these standards, areas can be recognized that are in need of possible noise mitigation. The analysis that follows characterizes existing traffic noise levels in the project area, assesses the effect of the project on future noise levels, and analyzes potential mitigation measures. The noise analysis consisted of selecting specific receptor sites and modeling existing and future noise levels. Analyzed receptor sites consist of the outdoor areas of residential and commercial properties. Background Noise is defined as any unwanted sound. Sound travels in a wave motion and produces a sound pressure level. This sound pressure level is commonly measured in decibels. Decibels represent the logarithmic measure of sound energy relative to a reference energy level. A sound increase of three dBA is barely perceptible to the human ear, a five dBA increase is clearly noticeable, and a 10 dBA increase is heard twice as loud. For highway traffic noise, an adjustment, or weighting, of the high- and low-pitched sounds is made to approximate the way that an average person hears sounds. The adjusted sound levels are stated in units of "A-weighted decibels" (dBA). In Minnesota, traffic noise levels that are exceeded 10% and 50% of the time during the hour of the day and/or night that. has the heaviest traffic. These numbers are identified as the L1o and Lso levels. City of Elk River Draft Alternative Urban Areawide Review August 2011 Page 8l of 90 ~i n