Laserfiche WebLink
Metadata
Document management portal powered by Laserfiche WebLink 9 © 1998-2015 Laserfiche. All rights reserved.
•= BOL_TON 8� M� N K, I NC� <br />. Consuiting Engineers & Sunreyors <br />" 12224�NicolletAvenue • Burnsville, MN 55337 <br />Phone (952j 890-0509 • Fax (952) 890-8065 <br />www.bolton-menk.com <br />MEMORANDUM <br />Date: November 9, 2011 <br />To: Terry Maurer, P.E.; Public Works Director <br />City of Arden Hills <br />From: Christopher S. Chromy, P.E., P.T.O.E. <br />Subject: TH 10/CSAH 96 Noise Analysis Peer Review <br />Per the request of the City of Arden Hills, Bolton & Menk has reviewed two formal noise studies that <br />were completed in the area of TH 10 and`CSAH 96. These included the TH 10 Barrier Study, dated <br />March 18, 2008 and the Environmental Assessment CSAH 96 and US 10 Grade Separation Project, <br />�proved bYMn/DOT Office of State Aid on October 25, 2010. In addition, we have reviewed the <br />October 11, 2011 review letter from Peter Wasko at Mn/DOT to James Tolaas at Ramsey County. Below <br />is a summary of our review relative'to residences along Lakeshore Place/Old Hwy lO located southwest <br />of the TH 10/CSAH 96 intersection: <br />• The combination of the two referenced studies provides sufficient analysis of noise conditions <br />and potential mitigation strategies for this azea. The two studies overlap the area in question. <br />Additional study would result in the same conclusion and therefore not necessary. <br />• Recognizing the studies were conducted independent from one another and for sepazate proposed <br />highway projects; their results in overlapping areas vary a bit. This is due to slightly different <br />assumpUons and modeling inputs. While a bit different, both sets of results appear valid and <br />generally consistent. <br />• Both studies provide the same general� conclusions for the area in question. Both found current <br />noise levels exceed state and federal thresholds and warrant consideration of noise mitigation. <br />Both found noise mitigation could be feasible in reducing highway noise levels by 5 dBa or more <br />for adjacent residences. Both found the cost effectiveness of noise mitigation would NOT be <br />reasonable relative to established thresholds. <br />� I have contacted Anne Claflin at the Minnesota Pollution Control Agency (MPCA) to confirm <br />that platted residential lots without homes are not to be included in cost effectiveness analysis. <br />Even with the addition of three platted lots into the calculation, the noise mitigation costs would <br />remain above the established reasonableness threshold of $3250 per decibel reduced per <br />residence. <br />• The conclusion in the October 11, 2011 memo that "There is simply not enough density of <br />residences to meet the cost effectiveness threshold" is valid and summarizes the conclusion of <br />both studies accurately. <br />Neither Mn/DOT nor Ramsey County is offering to include noise mitigaUon up to the cost effectiveness <br />threshold with remainder of cost being bome by the city. On the contrary, any noise mitigation as part of <br />this project would need to be shouldered by the city or other local source in its entirety. <br />H:IARDI-I�T42022335\1_Corres\110911 10-96 Noise Review Memo.doc <br />DESIGNING FOR A BEiTER TOMORROW <br />°Bolton & Menk is an equal opportunity employer <br />