REVIEWED PLN RESUB 4-Noise Survey+10.31.2022_2.47.44_PM+31948973COUStics
-t Nelsen Esselstrom
July 25, 2022
Vanessa Fedotov
Synergy
2500 Redhill Avenue 240
Santa Ana, CA 92705
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Reviewed by
City of Edmonds ;
Planning Division
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Re: Acoustical Report — T-Mobile SE01705E N Firdale Village/Dental
Site: 10014 238' Street SW, Edmonds, WA 98020
Dear Vanessa,
RESUB
Nov 01 2022
CITY OF EDMONDS
DEVELOPMENT SERVICES
DEPARTMENT
BLD2022-0769
This report presents a noise survey performed in the immediate vicinity of the proposed
T-Mobile telecommunications facility at 3595 Sunrise Road On Bellingham, Washington. This
noise survey 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 they relate to the
criteria.
Code Requirements
The site is located within the City of Edmonds zoning jurisdiction on property with a BN zoning.
The receiving property to the north is zoned BN. All of the other properties are zoned RS-8.
Edmonds City Code 5.30.020 defines BN as within a "Business" zone and R zonings as within a
"Residential district".
The proposed new equipment consists of an emergency generator. The generator will run once
a week during daytime hours only for maintenance and testing purposes.
Under Edmonds City Code Chapter 5.30.040 noise from equipment on a "Business" property is
limited as follows:
Business Receiver: Noise is limited to 60 dBA during daytime hours.
Residential Receiver: Noise is limited to 57 dBA during daytime hours.
Additionally, Edmonds City Code 5.30.050.B allows that during any one -hour period the maximum
permissible noise level may be exceeded bye dBA for a 15-minute period. The generator must
not exceed 65 dBA at the receiving property to the north and 62 dBA at the other receiving
properties during daytime maintenance and testing. The generator is exempt during emergency
operation.
AT&T
SE01705E N Firdale Village/Dental
Ambient Conditions
Page 2
Existing ambient noise levels were measured on site with a Svantek 979 sound level meter on
July 22, 2022. Measurements were conducted as close to the proposed location as possible and
the property lines in accordance with the State of Washington code for Maximum Environmental
Noise Levels WAC 173-60-020. The average ambient noise level was 52 dBA.
Predicted Equipment Sound Levels
Emergency Equipment
The proposed equipment includes one Generac RD048 48 KW generator with a sound enclosure
which has a sound level of 65 dBA at 23 feet. The generator will be located at grade surrounded
by a wood fence. The nearest residential receiving property is approximately 30 feet south of the
generator. The following are the predicted sound levels at the receiving property:
Table 1: Predicted Noise Levels: Proposed Emergency Generator
1
ApplicationLine
Equipment Sound Pressure Level at 23 ft. (dBA), Lp1
71
2
Noise Reduction — Wood Fence
-3
3
Distance Factor (DF)
Inverse -Square Law Free Field): DF = 20lo d1/d2
-2
30 ft
4
New Equipment Sound Pressure Level at Receiver, Lpr
60
As shown in Table 3, the sound pressure level from the proposed generator during test cycle
operation with the proposed mitigation is predicted to be 60 dBA at the nearest receiving property
to the south, which meets the 62 dBA residential code limit. Noise levels at other receiving
properties, which are further away, will be lower and within code limits.
Please contact us if you have any questions or require further information.
Sincerely,
SSA Acoustics, LLP
Steven Hedback
Acoustical Consultant
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 so 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 liability 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 therein 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 riaht to review the information. reassess anv new potential concerns and modifv our opinions accordinalv.