HomeMy WebLinkAboutCUP 12-13; SDG&E Steel Pole; Conditional Use Permit (CUP) (5)TABLE OF CONTENTS
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1.0 EXECUTIVE SUMMARY 1
2.0 INTRODUCTION 1
2.1 Project Location
2.2 Project Description
2.3 Applicable Noise Regulations
3.0 ENVIRONMENTAL SETTING 2
3.1 Existing Noise Environment
3.2 Future Noise Environment
4.0 METHODOLOGY AND EQUIPMENT 3
4.1 Methodology
4.2 Measurement Equipment
5.0 NOISE IMPACTS 4
6.0 CONCLUSION 5
7.0 CERTIFICATION 6
8.0 REFERENCES 6
FIGURES
1. Vicinity Map
2. Assessor's Parcel Map
3. Satellite Aerial Photograph
4. Topographic Map
5. Satellite Aerial Photograph Showing Equipment Noise Contours and Receiver Locations
APPENDICES
A. Project Plans, Dated July 9, 2013
B. Pertinent Sections of the City of Carlsbad Noise Guidelines Manual
C. Manufacturer Data Sheets
D. Cadna Analysis Data and Results
1.0 EXECUTIVE SUMMARY
The proposed project, the Sprint wireless telecommunications facility to be known as "SDG&E Steel
Pole #Z718327" (Site Number SD34XC861 D), consists of the installation of a new equipment lease
area to contain wireless equipment cabinets and associated antennas. The project site is located at
1926 Swallow Lane in the City of Carlsbad, California.
The purpose of this report is to assess noise impacts from the proposed equipment at the Sprint
facility, and to determine if mitigation is necessary and feasible to reduce project related noise
impacts to less than significant. Noise limits specified within the City of Carlsbad Noise Guidelines
Manual must be met at neighboring property lines.
Calculations show that, as designed, exterior noise levels from the proposed Sprint equipment will
comply with the applicable noise limits defined by the City of Carlsbad at all surrounding property
lines and sensitive receivers. Additionally, interior noise levels are not expected to be compromised
by Sprint equipment on site. No mitigation is deemed necessary for attenuating exterior or interior
noise levels on site.
2.0 INTRODUCTION
This acoustical analysis report is submitted to satisfy the noise requirements of the City of Carlsbad.
Its purpose is to assess noise impacts from on-site project related mechanical noise sources, and to
determine if mitigation is necessary to reduce the noise impacts to Jess than significant levels.
All noise level or sound level values presented herein are expressed in terms of decibels (dB), with
A-weighting, abbreviated "dBA," to approximate the hearing sensitivity of humans. Time-averaged
noise levels are expressed by the symbol "LEo" unless a different time period is specified, "LEo" is
implied to mean a period of one hour. Some of the data may also be presented as octave-band-
filtered and/or A-octave-band-filtered data, which are a series of sound spectra centered about each
stated frequency, with half of the bandwidth above and half of the bandwidth below each stated
frequency. This data is typically used for machinery noise analysis and barrier calculations.
Sound pressure is the actual noise experienced by a human or registered by a sound level
instrument. When sound pressure is used to describe a noise source, the distance from the noise
source must be specified in order to provide complete information. Sound power, on the other hand,
is a specialized analytical method to provide information without the distance requirement, but it
may be used to calculate the sound pressure at any desired distance.
2.1 Project Location
The subject property is located at 1926 Swallow Lane in the City of Carlsbad, California. The
Assessor's Parcel Number (APN) for the site is 215-052-13. The owner of the property is the West
Bluff Condominium Association. An existing condominium complex currently occupies the site.
For a graphical representation of the site, please refer to the Vicinity Map, Assessor's Parcel Map,
Satellite Aerial Photograph, and Topographic Map provided as Figures 1 through 4, respectively.
Eilar Associates, Inc. Job #B30406N1 February 26, 2014 Page 1
2.2 Project Description
The proposed project includes the installation and operation of new equipment cabinets and
associated antennas. All equipment will be mounted on a concrete slab within a seven-foot high
CMU wall enclosure at grade. The wireless equipment cabinets are the focus of this analysis, as
they are the only noise-generating equipment to be located on site. No other wireless carrier
equipment is currently located on site.
For additional project details and equipment positioning, please refer to the project plans, dated July
9, 2013, provided in Appendix A.
2.3 Applicable Noise Standards
The noise regulations applicable to this project are limited, and are contained within the City of
Carlsbad Noise Guidelines Manual, and the Noise Element to the General Plan, which states that
noise levels outside the Palomar Airport noise impact area shall be controlled to 60 CNEL at
residential property lines, and 45 CNEL at the interior of residences. Another relevant document is
the City of Carlsbad Council Policy Statement on Wireless Communications Facilities, dated
September 21, 2001. According to these regulations, the noise limits for a single-family residential
zone are 60 CNEL and 45 CNEL for exterior and interior noise levels, respectively. Although noise
levels in the guidelines manual are set using the CNEL metric, which is typically reserved for
describing transportation noise, the noise limits will be applied as hourly decibel limits, which is a
more appropriate metric for describing mechanical noise. The proposed project site is zoned for
residential use, as are neighboring properties to the north and east. Neighboring property to the
south and west is generally open space, with some residential property beyond this area. Property
line noise limits of 60 dBA were used for this analysis for all surrounding property lines and
sensitive receivers.
Pertinent sections of the City of Carlsbad noise regulations provided as Appendix B.
3.0 ENVIRONMENTAL SETTING
3.1 Existing Noise Environment
3.1.1 Ambient Noise
An on-site inspection was conducted at 2:20 p.m. on Monday, April 22, 2013. The weather
conditions were as follows: winds at 5-7 mph, partly cloudy skies, low humidity, and temperatures
in the mid 60's. An ambient noise measurement was taken to the southeast of the proposed Sprint
equipment location, for a duration of ten minutes. The microphone position was approximately five
feet above the existing grade. The measured noise level can be seen in Table 1. The current noise
environment primarily consists of traffic noise, with some noise from high voltage power lines
overhead and aircraft overflight.
Eilar Associates, Inc. Job #B30406N1 February 26, 2014 Page2
Table 1. On-5ite Noise Measurement Conditions and Results
Date Monday,April22,2013
Time 2:20 p.m. -2:30 p.m.
Conditions Partly cloudy skies, winds at 5-7 mph,
temperature in the mid 60's with low humidity
Measured Noise Level 50.6 dBA LEa
3.1.2 Existing Equipment Noise
There is no existing Sprint equipment on site, nor is there any other existing carrier equipment on
site. Proposed Sprint equipment is the focus of this analysis.
3.2 Future Noise Environment
The future noise environment in the vicinity of the project site will be primarily a result of the same
noise sources, as well as the noise generated by the proposed equipment at the Sprint facility.
The proposed project includes the installation of two Modcell cabinets and two EZBF battery
cabinets, model 60ECv2. The maximum noise level created by one Modcell unit is measured to be
approximately 65 dBA at five feet from the back of the cabinet. According to Alcatel Lucent, there
are no noise-generating components in the EZBF cabinet, and therefore, this equipment has not
been incorporated into calculations. Manufacturer data sheets can be found in Appendix C. In
order to incorporate the measurement of Modcell cabinet noise into the Cadna analysis, octave
band data from a previous measurement of a typical wireless equipment cabinet was adjusted to
approximate the sound spectrum. The resultant octave band data is shown in Table 2.
Table 2. Predicted Octave Band Sound Pressure Levels for On-5ite Equipment at 5 Feet
Octave Band Frequency Sound Pressure Level (dB)
Location dBALEa
63 125 250 500 1K 2K 4K BK
Modcell4.0 78.0 68.9 60.6 60.6 59.5 55.8 57.1 48.2 65.0
No other proposed equipment is anticipated to generate a significant amount of noise on site.
4.0 METHODOLOGY AND EQUIPMENT
4.1 Methodology
Modeling of the outdoor noise environment is accomplished using Cadna Version 3.7, which is a
model-based computer program developed by DataKustik for predicting noise impacts in a wide
variety of conditions. Cadna (Computer Aided Noise Abatement) assists in the calculation,
presentation, assessment, and mitigation of noise exposure. It allows for the input of project
Eilar Associates, Inc. Job #B30406N1 February 26, 2014 Page 3
information such as noise source data, barriers, structures, and topography to create a detailed
model and uses the most up-to-date calculation standards to predict outdoor noise impacts.
4.2 Measurement Equipment
Some or all of the following equipment was used at the site to measure existing ambient noise
levels:
• Larson Davis Model 720 Type 2 Sound Level Meter, Serial# 0312
• Larson Davis Model CA150 Type 2 Calibrator, Serial# 0339
• Distance measurement wheel, digital camera
The sound level meter was field-calibrated immediately prior to the noise measurement and
checked afterwards, to ensure accuracy. All sound level measurements conducted and presented
in this report, in accordance with the regulations, were made with sound level meters that conform
to the American National Standards Institute specifications for sound level meters (ANSI S1.4-1983,
R2001 ). All instruments are maintained with National Bureau of Standards traceable calibration, per
the manufacturers' standards.
5.0 NOISE IMPACTS
Noise levels of the proposed wireless equipment were calculated using Cadna at the neighboring
residential property to the north and at the two nearest on-site condominium buildings to the east of
the equipment area. Any other potentially noise-sensitive receivers are located at a greater
distance from proposed equipment, and therefore, the calculated receivers represent the worst-
case noise exposure, and all other property lines will be exposed to lesser noise levels due to
distance attenuation and intervening structures. Receivers were calculated at a height of five feet
above grade. Noise levels were calculated without considering the shielding provided by the
proposed seven-foot high wall around the Sprint equipment, which will provide additional sound
attenuation at surrounding ground-level receivers, but will provide little to no attenuation at second
story receivers.
Results of the analysis are shown in Table 3 below. Noise contours and receiver locations are
shown in Figure 5. Additional information can be found in Appendix D.
Table 3. Calculated Wireless Facility Noise Impact Levels
Receiver Approximate Noise Limit Equipment Noise Level Receiver Location Distance to Number Equipment (ft) (dBA) (dBA)
R1 North Property Line 185 60 34.7
R2 On-Site Building -1 180 60 35.1
R3 On-Site Building-2 170 60 35.5
Eilar Associates, Inc. Job #B30406N1 February 26, 2014 Page4
As shown above, even without the proposed seven-foot high enclosure wall in place, equipment
noise levels are expected to comply with the noise limit of 60 dBA at the nearest noise-sensitive
properties. Noise levels at these receivers are considered to be conservatively high for ground-
level receivers, as the proposed seven-foot high enclosure wall will provide additional noise
attenuation in these locations. Noise levels shown for R2 and R3 above are expected to be
representative of noise levels at second story receivers at the adjacent condominium buildings, and
still do not exceed the 60 dBA threshold. Any other noise-sensitive receivers are located at a
greater distance from proposed equipment and will be exposed to lesser noise levels due to
distance attenuation and shielding provided by intervening structures. For this reason, no mitigation
is deemed necessary for attenuating exterior noise levels.
Noise impacts within on-site condominiums would also be insignificant as a result of wireless
equipment operation. Contemporary exterior building construction is expected to achieve at least
15 decibels of exterior-to-interior noise attenuation with windows opened. Therefore, in order to
meet the 45 dBA interior noise limit, noise levels at the building facade must not exceed 60 dBA.
As shown above, the maximum noise level at a residential building facade was calculated to be
35.5 dBA without attenuation achieved by the surrounding wall that would be experienced at first
floor receivers. As this value is less than the 45 dBA interior noise threshold, it can be concluded
that interior noise levels of the first and second story on-site condominiums will not exceed 45 dBA
as a result of wireless equipment on site. No mitigation is deemed necessary to attenuate on-site
interior noise impacts.
6.0 CONCLUSION
Calculations show that, as designed, exterior noise levels from the proposed Sprint equipment are
expected to meet the applicable noise limits defined by the City of Carlsbad at all surrounding
noise-sensitive receivers. Additionally, interior noise levels are not expected to be compromised by
Sprint equipment on site. No mitigation is deemed necessary for attenuating exterior or interior
noise levels on site.
This analysis is based upon a current worst-case scenario of anticipated, typical equipment for this
type of wireless facility. Substitution of equipment with higher noise emission levels may invalidate
the recommendations of this study. These conclusions and recommendations are based on the
best and most current project-related information available at the time this study was prepared.
Eilar Associates, Inc. Job #B30406N1 February 26, 2014 Page 5
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CITY OF CARLSBAD Noise Guidelines Manual
SUMMARY
The following Is a summary of the most frequently requested City noise policies. Information
contained in this summary is described in more detail In the body of the Noise Guidelines
Manual.
Residential Exterior Noise Standard
It Is the policy of the City that 60 decibel dB(A) CNEL Is the exterior noise level to which
residential units must be mitigated, except that for areas impacted by McClellan Palomar Airport
shall be mitigated to 65 decibel dB(A) CNEL
Residential Interior Noise Standard
Interior noise levels for all residential units shall be mitigated to 45 dB(A) CNEL when openings
to the exterior of the residence are closed. If openings are required to be closed to meet the
interior noise standard then mechanical ventilation shall be provided.
Threshold for Regulrlna Noise Reports on Residential Prolect
A noise report shall be required for all residential projects within the following noise referral zones
(refer to the Carlsbad Future 2010 Noise Contour Map Flgure-i or see the 1000' scale map'
provided at the back of this document):
a. Residential projects requiring a discretionary permit containing five or more dwelling units
or any multiple family dwelling units located within or 500-feet beyond the 60 dB(A) CNEL
noise contour line of the Noise Contour Map approved as part of the Carlsbad General
Plan.
b. Within the McClellan-Palomar Airport 60 dB{A) CNEL Noise contour line as shown on the
1995 Noise Contour Map ofthe McClellan-Palomar Airport Comprehensive Land Use Plan
(CLUP) see Flgure-ii.
11000' scale map will be included in final document only.
Summary i
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Product overview for 9928 Distributed Base Station
Outdoor cabinet
60ECv2 battery cabinet dimensions
60ECv2 battery cabinet overview
The following diagram shows the weight and dimensions for the 60ECv2 battery cabinet.
2-18
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1-787cm__J (31") I
-Cabinet shipping weight:
193 kg (425 lbs)
-Fully equipped cabinet
with 12JR145 batteries.
Weight: 1,093 kg (2,4051bs)
Alcatei-Lucent -Proprietary
Use pursuant to applicable agreements
9928 Dist BTS Outdoor
401-703-732
Issue 6 October 2012
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EILAR ASSOCIATES, INC.
Acoustical and Environmental Consulting
Cadna Noise Model ~ Sound Levels
Name ID Type Oktave Spectrum (dB} Source
Weloht I 63 125 I 250 500 1000 I 2000 4000 8000 A I lin
Mod cell L 1 Lw(c) I 92.6 83.5 I 75.2 75.2 74.1 I 70.4 71.7 62.8 79.6 I 93.4 Mfr/Meas
Page 1 of 3
EILAR ASSOCIATES, INC.
Acoustical and Environmental Consulting
Cao na Nois • Model • Poi
Name ID Result. PWL .w/Li Height
Day Type Value X y z
(dBA (m) (m) (m)
Modcell Cabinet S_1 79.6 Lw 67.47 91. 1.52
Modcell Cabinet S_2 79.6 Lw 6; .38 89.2• 1.52
Page 2 of3
EILAR ASSOCIATES, INC.
Acoustical and Environmental Consulting
Cadna Noise Model ~ Noise Levels at Receivers
Name ID LeveiLr Height Coordinates
Day X y z
(dBA) (m) (m) (m) (m
North R 1 34.7 1.52 72.46 147.94 1.52
On~Site Residence1 R2 35.1 1.52 117.58 65.56 1.52
On·Site Residence2 R 3 35.5 1.52 119.63 100.53 1.52
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