2022-03-24 Bionomics Environmental Sound Study ■ ■
1W
Dave Aizpitarte
Bionomics Environmental, Inc.
1045 East Winding Creek
Eagle ID 83616
208-939-1022
1 visited Phase Two of the Overland Wells proposed site 3/24/2022 and its proximity to 1-84. Similar to
Phase One, in my professional opinion, double-paned windows are preferable to a noise wall and
provide adequate noise abatement for this site.
Dave Aizpitarte background
David Aizpitarte has performed and supervised all aspects of traffic noise studies, including all field
sampling using FHWA procedures for sampling and quality control. He performed and supervised
computer modeling using Stamina 2.0,TNM 1.0, and TNM 2.5 for modeling present and future traffic
noise impacts. He has attended classes in traffic noise analysis including seminars presented by Bowlby
and Associates and HMMH Inc. (developers of TNM). He is a traffic noise expert witness for the ACHD
and the ITD and has served both on an advisory group for the upgrade of TNM and the ITD noise policy.
He has performed a wide variety of traffic noise studies throughout Idaho and Montana in support of
road design, airports and facilities expansion.
1 The location is relatively far away from the 1-84 centerline. Bionomics designed (non-engineering)the
noise walls across from the Boise Airport on the north side of 184. The regulations did not require us to
study receptors similar to the Overland Wells Phase Two proposed apartment complex located further
away than ones located adjacent to 184.The further a potential sensitive receptor is from a noise source
(184)the more community noise becomes a factor.
2. Similar to Phase One, the elevational difference and terrain features cover up the tires of the vehicles
both on the eastbound off-ramp and 184.This would be a benefit for the first level (ground floor) of the
apartments. At higher speeds tire noise is the predominant noise source and having them obscured by
terrain can be sufficient mitigation. From what I observed I feel this is the case at this proposed project
location.
3. ITD noise policy does not contemplate any mitigation for second or third floors of receptors in an
apartment complex. The noise walls are typically not feasible from an engineering basis (too tall,
structurally unsound) and not reasonable from a cost basis. I would recommend mitigation such as
double paned windows and minimize the window openings facing the freeway.A Light Frame Ordinary
Sash (closed) window will give you a 20 dB reduction in interior sound levels, Storm Windows will give
you a 25 dB reduction.This is a cost effective and superior mitigation to noise walls that start a 7 dB
reduction per receptor and again,walls only mitigate for the receptors directly behind them.
4. From an esoteric standpoint,walls can be claustrophobic and conflict with the view of the foothills
(visual impacts). For example, Bionomics was able to design a wall for the Renaissance apartment
complex on Chinden that met both engineering (Feasibility) and cost (Reasonability) criteria set by the
FHWA (Federal Highway Administration).The owners felt that the wall would disrupt the view and give
the apartment complex a "penitentiary" look. They declined (desirability)the wall. The same issue
happened on the south east quadrant of the Ten Mile interchange. Similar to this proposed project the
terrain features of the off ramp offered noise mitigation and the neighborhood was unanimous in
retaining their view of the foothills.
I hope this will give you a good case and please review and give me any comments or corrections.
Dave Aizpitarte
Principal
Bionomics Environmental, Inc.
Picture One. Approximate location of Apartment Complex
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Picture Two Location at fence line