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Memorandum <br />SRF No. 12818.00 <br />To: Jeremy Larson, Executive Vice President <br />Hampton Companies, LLC <br />From: Justin Sebens, PE, Senior Engineer <br />Brett Danner, Senior Associate <br />Date: June 26, 2019 <br />Subject: Hampton Companies Assisted Living/Extended Care Facility <br />Traffic Noise Analysis <br />Ramsey, Minnesota <br />Introduction <br />As requested, a traffic noise study was completed for a proposed assisted living/extended care <br />facility in the City of Ramsey, Minnesota. The proposed facility is located on the south side of <br />Highway 10, east of Ramsey Boulevard (County State Aid Highway 56). The site is currently <br />undeveloped. The concept plan for the proposed development site with the assisted living/extended <br />care facility is attached. <br />The purpose of this study was to identify existing noise levels at the proposed assisted <br />living/extended care facility and complete a traffic noise analysis for the proposed development <br />consistent with the requirements identified in Minnesota Rules 7030.0030 (Noise Control <br />Requirement). <br />Background Information on Noise <br />Noise is defined as any unwanted sound. Sound travels in a wave motion and produces a sound <br />pressure level. This sound pressure level is commonly measured in decibels. Decibels (dB) represent <br />the logarithm of the ratio of a sound energy relative to a reference sound energy. An adjustment, or <br />weighting, of the high- and low- pitched sound is made to approximate the way that an average <br />person hears sound. The adjusted sound levels are stated in units of "A -weighted decibels" (dBA). A <br />sound increase of 3 dBA is barely noticeable by the human ear, a 5 dBA increase is clearly <br />noticeable, and a 10 dBA increase is heard as twice as loud. For example, if the sound energy is <br />doubled (e.g., the amount of traffic doubles), there is a 3 dBA increase in noise, which is just barely <br />noticeable to most people. On the other hand, if the sound energy increases by a factor of ten times, <br />the resulting sound level will increase by about 10 dBA and be heard to be twice as loud. <br />In Minnesota, traffic noise impacts are evaluated by measuring and/or modeling the noise levels that <br />are exceeded 10 percent and 50 percent of the time during the hours of the day and/or night that <br />have the loudest traffic scenario. These numbers are identified as the Lio and L50 levels, respectively. <br />www.srfconsulting.com <br />1 Carlson Parkway North, Suite 150 1 Minneapolis, MN 55447-4453 1 763.475.0010 Fax: 1.866.440_6364 <br />An Equal Opportunity Employer <br />