7A, Noise Wall for 35W & US Hwy 10 - Resolution 2009-021

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MEMORANDUM DATE: September 8, 2009 TO: Mayor and City Council Ron Moorse, City Administrator FROM: Kristine Giga, Civil Engineer SUBJECT: Resolution supporting a noise wall along the north side of County State Aid Highway 96 between Interstate 35 West and US Highway 10 BACKGROUND/DISCUSSION Ramsey County is developing plans to reconstruct the intersection of County Highway 96 (CSAH 96) and US Highway 10 (TH 10). As part of the process and in accordance with state and federal environmental rules, the County has evaluated a number of issues along the corridor. One of the issues analyzed was highway noise. The noise analysis has indicated that highway noise in the northwest quadrant of the intersection would exceed state standards. A noise wall was evaluated at this location as a potential means for mitigating the noise levels. The analysis concluded that a noise wall in this area would meet the cost reasonableness criteria. This proposed noise wall location is shown on the attached drawing. Also shown are the approximate shadows that would be created both by a 10-foot high and a 20-foot high wall at different times of the day and at different times of year. A brief summary of the impacts of the noise walls is listed below. i n, NnicP «roil -reduces noise for 16 residences -average level of noise reduction is 7.1 dBA 20' Nome, wall -reduces noise for 35 residences -average level of noise reduction is 11.5 dBA A public hearing was held on August 31, 2009, to receive input from property owners adjacent to the proposed noise wall. A draft copy of the meeting minutes is attached. A question was raised at the public hearing regarding the type of pavement used in the noise analysis. Ramsey County's consultant confirmed that the MINNOISE model is based on an average pavement surface. It is neither a new smooth surface, nor an old rough surface. It is also neither specifically bituminous nor concrete. Resolution 2009-021 is attached; the language in the resolution currently states "10-foot or 20-foot" noise wall, in reference to the height of the proposed noise wall. Ramsey County is requesting that CADocuments and Settings\becky.brazys\Local Settings\Temporary Internet Files\OLK15F\09-14-09Memo NoiseWall.doc