June 30, 2025
Epic Wireless Group
8700 Auburn Folsom Road, Suite 400
Granite Bay, CA 95746
Re: Noise Assessment Letter
32975 Alvarado-Niles Rd.,
Union City, CA 94587
Site CBL00155- Alvarado-Niles Road & Medallion Drive is a proposed AT&T Macro site located in the Union City Jurisdiction, CA. AT&T is proposing to add a pre-manufactured equipment cabinet with a door mounted heat exchanger and a new emergency backup generator. Based on our review of the project drawings and technical specifications, the following is a summary of our noise assessment of the proposed equipment.
Per City of Union Chapter 9.40 Community Noise Standards
9.40.30 Definitions
D. "Local ambient" or "local ambient noise level" means the lowest sound level repeating itself at a certain location during a six-minute period as measured with a precision sound level meter, using slow response and "A" weighting. The local ambient noise level shall be determined with the noise source at issue silent, and in the same location as the measurement of the noise level of the source or sources at issue. However, for purposes of this chapter, in no case shall the local ambient be considered or determined to be less than 40 dBA. If a significant portion of the local ambient is produced by one or more individual identifiable sources which would otherwise be operated continuously during the six-minute measurement period and contributing significantly to the ambient sound level, determination of the local ambient shall be accomplished with these separate identifiable noise sources silent.
9.40.41 Residential property noise limits
No person shall produce, suffer or allow to be produced by any machine, animal or device, or any combination of same, on residential property, a noise level more than 10 dBA above the local ambient at any point outside of the property plane.
9.40.42 Commercial and industrial property noise limits No person shall produce, suffer or allow to be produced by any machine or device, or any combination of same, on commercial or industrial property, a noise level more than twelve dBA above the local ambient at any point outside of the property line.
9.40.43 Public property noise limits
A. No person shall produce, suffer or allow to be produced by any machine or device, or any combination of same, on public property, a noise level more than fifteen dBA above the local ambient at a distance of twenty-five feet or more, unless otherwise provided in this chapter. 7430 New Technology Way, Suite 150
Frederick, MD 21703
(703) 596-1022 Office
(540) 242-3195 Fax
www.waterfordconsultants.com
ATTACHMENT 7
B. B. Sound performances and special events not exceeding eighty dBA measured at a distance of fifty feet are exempt from this chapter when approval therefore has been obtained from the appropriate governmental entity, except as provided elsewhere in this Code.
C. C. Vehicle horns, or other devices primarily intended to create a loud noise for warning purposes, shall not be used when the vehicle is at rest, or when a situation endangering life, health, or property is not imminent.
NOISE ANALYSIS
Of the supporting equipment planned for this project, Table 1 below presents the primary noise sources of concern.
Table 1 – Supporting Equipment Noise Data
Noise
Source
Equipment
Type
Make Model Size
Manufacturer’s
Published Noise
Data (dBA)
Noise Data
Reference
Distance (ft)
A AC Cabinet Delta WUC ESOF030-HCU01 -- 75 5
B Generator Generac SDC030 30kW 63(1) 23
[1] Sound pressure is based on Gen Set with Level 2 sound attenuated enclosure, full-load operating conditions.
Our review of the package did not reveal any other significant noise sources. The equipment is proposed to be installed on private property behind an 8’ high CMU wall with stucco finish.
To properly present this assessment, our noise modeling has assumed the following scenarios:
1) Ambient noise is not considered.
2) Heat Exchanger on the pre-manufactured equipment cabinet runs continuously. 3) The generator is operating in full load condition.
4) Our analysis does not include noise reduction factors such as air attenuation, vegetation and ground effects, which become significant at large distances and, 5) other existing on-site equipment creating noises are ignored.
The subject site and its adjacent properties are located within the Union City Jurisdiction, and the telecommunications compound sit within the APN 475-0148-002 property. The nearest adjacent property line is located to the South on APN 475-0171-104. Property use is Residential. The measurement of sound shall be taken from the nearest site’s property line, towards the source of the sound, which equates to 93ft distance from cabinet A/C unit to the property line and 98ft from the generator to property line horizontally.
Generator is for emergency backup during power failure conditions. Generator is exercised once a week for one half hour maximum during daytime hours only. A/C unit on the pre-manufactured cabinet can run 7430 New Technology Way, Suite 150
Frederick, MD 21703
(703) 596-1022 Office
(540) 242-3195 Fax
www.waterfordconsultants.com
Digitally signed by Robert Jerry
Lara -- Stantec
Date: 2025.07.01 09:23:05-04'00'
continuously. Unit will run during the day and nighttime. Noise levels measurements per Table 1, calculated to the property line of the nearest property, are as follows:
Noise Source ‘A’ – A/C Cabinet = 40.1 dBA
Noise Source ‘B’ – Generator = 43.0 dBA
Combined Sources – Total of 45 dBA
Based on the Union City Jurisdiction ordinance, the anticipated noise level of the proposed equipment meets the Jurisdiction standard of 50dBA. i.e, ambient noise level plus residential property noise limits (40dBA + 10 dBA). As sound pressure levels attenuate with increasing distance from the sound source, noise levels due to the supporting equipment at all remaining surrounding property lines, are anticipated to be less than city`s requirements, meeting the noise standards outlined in this report.
CONCLUSION
Based on the project documentation, our noise assessment indicates that the proposed AT&T Telecommunications Facility complies with the requirements mandated by the Union City Jurisdiction at all adjacent property lines per stated noise metrics outlined in the above table. To avoid any misunderstanding, I hereby state that to the best of my knowledge, belief and professional judgment, this report represents an accurate appraisal of Vertical bridge equipment, based upon careful evaluation of Manufacturer’s data to the extent reasonably possible.
Please reach out if I can be of further assistance.
Respectfully Submitted,
Stantec Consulting Services Inc.
Robert J Lara
7430 New Technology Way, Suite 150
Frederick, MD 21703
(703) 596-1022 Office
(540) 242-3195 Fax
www.waterfordconsultants.com