HomeMy WebLinkAboutNoise Study 702132002
7409 Greenwood Avenue N
Seattle, WA 98103
March 24, 2020
Chris Jack
Ramaker & Associates, Inc.
855 Community Drive
Sauk City, WI 53583
Re: Acoustical Report – AT&T 10038051 Quilcene
Site: Elkhounds Pass and Center Road, Quilcene, WA 98376
Dear Chris,
The following report presents a noise study for the proposed AT&T telecommunications facility
near Elkhounds Pass and Center Road in Quilcene , WA. This noise study extends from the
proposed equipment to the nearest properties. The purpose of this report is to document the
existing conditions and the impacts of the acoustical changes due to the proposed equipment.
This report contains data on the existing and predicted noise environments, impact criteria and
an evaluation of the predicted sound levels as t hey relate to the criteria.
Ambient Conditions
Existing ambient sound levels of the site were measured on March 23, 2020 with a Svantek
971 sound level meter. Measurements were conducted as close to the proposed location as
possible. The average ambient noise level was 39 dBA primarily due to noise from nature
such as birds chirping and wind noise.
Code Requirements
The site is located within the Jefferson County Zoning jurisdiction on property designated with
a CF-80 (Commercial Forestry) zoning designation. The nearest receiving property to the
southwest is zoned RR-5 (Rural Residential). WAC 173-60-030 identifies properties used for
commercial forestry as Class C EDNA, and properties with residential use as Class A EDNA.
The proposed new equipment consists of an emergency generator. The generator will run
once a week during daytime hours for maintenance and testing purposes only.
Jefferson County Code 8.70.050 (1) requires noise levels to comply with WAC 173 -60. WAC
173-60-040 limits noise from equipment on a Class C EDNA property as follows:
Class A EDNA Receiver: Noise is limited to 60 dBA during daytime hours. During nighttime,
defined as the hours between 10 p.m. and 7 a.m., maximum sound levels are reduced by 10
dBA for receiving properties within Class A EDNA's.
Apr 08 2020
AT&T
10038051 Quilcene
Page 2
This report has been prepared for the titled project or named part thereof and should not be used in whole or part and relied upon for any
other project without the written authorization of SSA Acoustics, LLP. SSA Acoustics, LLP accepts no responsibility or liability for the
consequences of this document if it is used for a purpose other than that for which it was commissioned. Persons wishing to use or rely
upon this report for other purposes must seek written authority to do s o from the owner of this report and/or SSA Acoustics, LLP and agree
to indemnify SSA Acoustics, LLP for any and all resulting loss or damage. SSA Acoustics, LLP accepts no responsibility or li ability for this
document to any other party other than the person by whom it was commissioned. The findings and opinions expressed are relevant to the
dates of the works and should not be relied upon to represent conditions at substantially later dates. Opinions included the rein are based
on information gathered during the study and from our experience. If additional information becomes available which may affect our
comments, conclusions or recommendations SSA Acoustics, LLP reserves the right to review the information, reassess any new po tential
concerns and modify our opinions accordingly.
Additionally, WAC 173-60-040 allows that during any one -hour period, the maximum
permissible noise level may be exceeded by 5 dBA for a 15 minute period. Therefore, the
generator must not exceed 65 dBA when running during daytime hours for maintenance and
testing purposes. The generator is exempt during emergency operations.
Emergency Equipment
The proposed equipment includes one Kohler 30RWOZK 30 kW Diesel Generator with a Level
1 sound enclosure and has a sound level of 65 dBA at 23 feet.
Methods established by ARI Standard 275 -2010 and ASHRAE were used in predicting
equipment noise levels to the receiving properties. Application factors such as location, height,
and reflective surfaces are accounted for in the calculations.
The generator will be located at grade surrounded by a chain -link fence. The nearest receiving
property is approximately 530 feet southwest of the generator. The following table presents
the predicted sound level at the nearest receiving property:
Table 1: Predicted Noise Levels: Proposed Emergency Generator
Line Application Factor SW
1 Equipment Sound Pressure Level at 23 ft. (dBA), Lp1 65
2 Distance Factor (DF)
Inverse-Square Law (Free Field): DF = 20log (d1/d2)
-27
(530 ft)
3 New Equipment Sound Pressure Level at Receiver, Lpr 38
As shown in Table 1, the sound pressure level from the generator will meet the 65 dBA limit at
the nearest receiving residential property during test cycle operation. Noise levels at the other
receiving properties, which are further away, will be lower and within the code limits.
Please contact us if you have any questions or require further information.
Sincerely,
SSA Acoustics, LLP
Steven Hedback
Acoustical Consultant