Agenda - Council - 04/23/2002 - Laserfiche WebLink

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-118- Mr. Steve Jankowski Mr. Brian Olson April 18, 2002 Page 2 TH 47 is very high (approximately 97 percent), there will probably be a small percentage of trucks on the road at any time. Therefore, the estimate of nine dBA reduction in traffic noise from the proposed berm may be optimistic. Computer modeling and assumptions similar to those used to determine the effectiveness of a barrier at the Sunwood Estates development-would likely predict a noise reduction of 3 to 6 dBA for the proposed berm. Conclusions. Construction of a seVen-foot-high noise barrier as shown on the grading plan would likely reduce the worst case traffic noise levels in the development to be in compliance with or near the state daytime noise standard. Minnesota Rules Chapter 7030.0030 (Noise Control Requirement) requires municipalities 'to take reasonable measures to prevent the establishment of land use where noise standards would be immediately exceeded upon establishment of the land use. Based on the setting of the development and the estimated effectiveness of the proposed barrier, a seven-foot-high barrier (berm, solid fence or combination of the two) would constitute reasonable noise mitigation for this development. Recommendations Ifa fence is used as noise mitigation, it should be of high mass (i.e. wood plank of a thickness of one (1) inch or greater), should have no gaps (tongue in groove or overlapping plank constn~ction) and should extend all the way to the ground. This letter should be submitted to the MPCA for concurrence On the conclusion that a seven-foot-barrier represents reasonable noise mitigation. Sincerely, SRF CONSULTING GROUP, INC. Thomas G. Hillstrom Associate TGH/smf Attachment I I i I I I I i ! I ! ! I I ! I I !