Noise Study 5/27Bionomics Environmental, Inc.
1045 East Winding Creek
Eagle, ID 83616
Phone: 208-939-1022
FAX: 208-368-0001
Memo
To: Ryan Russell
Idaho Sand & Gravel
From: Kris Horton
Date: 5/27/11
Re: Addendum to Noise Study Southridge Gravel Mining Site
Introduction
Bionomics Environmental, Inc. was retained by Idaho Sand & Gravel of Nampa, Idaho to
perform and analyze a series of field noise measurements in the vicinity of the Southridge
Gravel Mining site at Overland Road, Meridian, Idaho. The purpose of the original study was
to assess whether noise generated at the site by the gravel crusher impacted surrounding
properties. Readings were taken on April 26, 2011 to measure the dBA levels during site
operation and without site operation. This addendum addresses continuing noise generated at
the site in the absence of the gravel crusher.
Field Results
Field-testing for this addendum was performed on May 23, 2011 at four locations during
operation of the gravel site without the gravel crusher. The noise level readings were taken
using a CEL -593.C1 precision impulse integrating sound level meter 51.4 Type 1. The meter
was calibrated using a CEL 284/2 calibrator before use and meteorological measurements
were taken. Each location consisted of two ten minute readings.
Table 2. Results of field testing at four locations in the vicinity of the
Southridge Gravel Mining site.
Location
pate
Time
dBA
Average dBA
2050 Aspen Cove Dr
5/24/11
4:29 prn
48
51
5/24/11
4:39 prn
53
2143 Aspen Cove Dr
5/23/11
3:06 prn
51
51
5/23/11
3:16 pm
50
2150 Aspen Cove Dr
5/23/11
3:30 prn
49
49
5/23/11
3:40 prn
48
2307 Aspen Cove Dr
5/23/11
3:53 pm
49
50
4:05 prn
51
Results
Table 3 compares the dBA levels during site operation with the gravel crusher, site operation
without the gravel crusher and dBA levels when the site is not operational.
Table 3. Comparison of site operation dBA levels with and without operation of the gravel
crusher at four locations and two locations without site operations in the vicinity of the
Southridge Gravel Mining site.
Location Average dBA,; operations
with gavel crusher*
AveragedBA, operations
without gravel crusher`
Average dBA without
site operations*
2050 Aspen Cove Dr 57
51
47
2143 Aspen Cove Dr 55
51
2150 Aspen Cove Dr 57
49
2307 Aspen Cove Dr 56
50
44
*See Idaho Sand Noise Memo 042811
Conclusions
Operation of the gravel crusher resulted in an average 10 decibel increase from ambient noise
levels at the four homes. These locations exhibited an average decrease of 6 dBA during site
operations without the gravel crusher, or an average increase of 4 dBA over ambient levels
due to site activities. This would be consistent with the noise produced during the gravel
crushing operation and noise attributed to the remaining activities during site operation. A 10
decibel increase is perceived as twice as loud, however a 4 decibel increase is slightly
perceptible to the human ear.
Idaho Sand & Gravel Noise Addendum 2
Photographs
Photograph 1. 2050 Aspen Covc Dr.
Photograph 3. 2150 Aspen Cove Dr.
Idaho Sand & Gravel Noise Addendum
Photograph 2. 2143 Aspen Cove Dr.
Photograph 4. 2307 Aspen Cove Dr.
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