Environmental Noise Assessment - Berkeley, California · Environmental Noise Assessment Report Site No. CNU1723 EBI Project No. 21110077 1700 Sixth Street, Berkeley, CA ... One RBA72

Environmental Noise Assessment Report Site No. CNU1723 EBI Project No. 21110077 1700 Sixth Street, Berkeley, CA

21 B Street Burlington, MA 01803 1.800.786.2346 i

Environmental Noise Assessment Report

Prepared for:

ATT Mobility 7655-7665 Redwood Blvd., Novato, CA 94945

Site No. CNU1723 Berkeley Mall 1700 Sixth Street Berkeley, California 94710 EBI Project No. 21110077 August 8, 2011


21 B Street Burlington, MA 01803 1.800.786.2346 ii

TABLE OF CONTENTS

1.0 EXECUTIVE SUMMARY .................................................................................................................... 3

2.0 BACKGROUND ................................................................................................................................ 3

3.0 SITE DESCRIPTION .......................................................................................................................... 5

4.0 AMBIENT SOUND LEVEL MEASUREMENTS ...................................................................................... 5

5.0 MODELED NOISE LEVELS ................................................................................................................ 7

6.0 RESULTS AND CONCLUSIONS ........................................................................................................ 8

7.0 LIMITATIONS ................................................................................................................................... 8

8.0 REVIEWER CERTIFICATION ............................................................................................................. 9

APPENDICES

Appendix A EBI – Environmental Noise Model Results Appendix B Equipment Specifications


21 B Street Burlington, MA 01803 1.800.786.2346

1.0 EXECUTIVE SUMMARY

AT&T proposes to locate one additional equipment cabinet on an existing unstaffed wireless telecommunications facility at the site CNU1723. This site is located on the main roof of a commercial building at 1700 Sixth Street in Berkeley, CA, and is herein referred to as Berkeley Mall. A study of the noise effects from the climate controlled equipment enclosures on surrounding properties was performed by EBI Consulting. Existing sound levels on the site property line and at nearby residential areas were not measured as part of this analysis. Acoustic modeling was done to assess equipment impacts from the installation’s climate controlled enclosures.

2.0 BACKGROUND

All sounds originate from a source. The sound energy, produced by a source, creates variations in air pressure which travel in all directions much like a wave ripples across the water. The “loudness” or intensity of a sound depends on the sound pressure level, defined as the ratio of two pressures: the measured sound pressure from the source divided by a reference pressure (i.e. threshold of human hearing). The most common approach to sound level measurement is to use the decibel (dB) scale. The decibel scale is logarithmic to accommodate the wide range of sound intensities the human ear is capable of responding to. On this scale, the threshold of human hearing is equal to 0 dB, while levels above 140 dB can cause immediate hearing damage. One property of the decibel scale is that the combined sound pressure level of separate sound sources is not simply the sum of the contributing sources. For example, if the sound of one source of 70 dB is added to another source of 70 dB, the total is only 73 dB, not a doubling to 140 dB. In terms of human perception of sound, a 3 dB difference is the minimum perceptible change for broadband sounds (i.e. sounds that include all frequencies). A difference of 10 dB represents a perceived halving or doubling of loudness. Environmental sound is commonly expressed in terms of the A-weighted sound level (dBA). The A-weighting is a standard filter to make measured sound levels more nearly approximate the frequency response of the human ear. Table 1 shows the adjustments made at each octave band frequency to contour un-weighted sound levels (dB) to A-weighted sound levels (dBA).



TABLE 1 - A-WEIGHTED OCTAVE BAND ADJUSTMENT (±dB)

Octave Band

Center Frequency

(Hz)

32 64 125 250 500 1000 2000 4000 8000 16000

A-weighting Adjustment

(±dB) -39.4 -26.2 -16.1 -8.6 -3.6 0.0 +1.2 +1.0 -1.1 -6.6

Environmental sound varies from moment to moment. Some sounds are sharp impulses lasting a very short time, while others rise and fall over much longer periods of time. There are various measures (metrics) of sound pressure designed for different purposes. The Leq, or equivalent sound level, is the steady-state sound level over a period of time that has the same acoustic energy as the fluctuating sound that actually occurred during that same time. The Leq is commonly referred to as the average sound level and is calculated automatically by the sound level meter using methods defined in ANSI S1.4-19831. The day-night average sound level (DNL or Ldn) is a sound level metric that is the 24-hour average sound level obtained after the addition of 10 decibels to sound levels in the night from 10 p.m to 7 a.m. This measure is referenced in the Federal Noise Regulations and is calculated using the mathematical expression below:

Where: Ldn = day-night average sound level Ld = daytime equivalent sound level (Leq [day] (dBA)) Ln = nighttime equivalent sound level (Leq [night] (dBA))

1 American National Standards Institute, ANSI S1-4-1983, American National Standard Specification for Sound Level Meters, 1983



3.0 SITE DESCRIPTION

The site CNU1723 is located on the rooftop of an existing commercial building at 1700 Sixth Street, Berkeley, CA. The nearest residential area is to the south of the project site. One additional wireless equipment cabinet is proposed near the north-central rooftop area. Figure 1 presents the equipment cabinet location, nearest property line and nearest residential structure. According to construction drawings, the nearest private residential structure from the property line is to the south, (see Figure 1), approximately 52 meters from the proposed equipment cabinet.

4.0 AMBIENT SOUND LEVEL MEASUREMENTS

No ambient sound level measurements were taken as part of this noise study. The noise impact from the equipment enclosures was the only source of sound analyzed.



FIGURE 1 – SITE SKETCH NEAREST NOISE SOURCE, RECEPTOR AND PROPERTY LINES EBI PN: 21110077 Site No.: CNU1723 1700 Sixth Street Berkeley CA

Nearest Residence

Nearest Property Line

Wireless Equipment Area



5.0 MODELED NOISE LEVELS

Post construction sound level effects from the proposed AT&T equipment at the property line and nearby residence were calculated with the EBI Consulting – Environmental Noise Model (EBI-ENM). EBI-ENM is a sophisticated spreadsheet model for sound propagation and attenuation based on International Standard ISO 96132 and other industry accepted calculation standards. Atmospheric absorption, the process by which sound energy is absorbed by the air, was calculated using the Volpe Method3 which is consistent with ANSI S1.26-19954. The absorption of sound assumed standard dry conditions and is significant at large distances. The EBI-ENM model uses the Modified Kurze-Anderson Formula5 to predict the insertion loss of any barriers intersecting the line-of-sight between the receiver and the sound source. To make the model more conservative, no barrier effects were included in the noise calculations. Complete modeling output sheets from the EBI-ENM are contained in Appendix B. Table 2 summarizes the results of the acoustic modeling. One RBA72 equipment cabinet containing a single climate control unit was modeled as a part of this analysis.

2 International Standard, ISO 9613-2, Acoustics – Attenuation of Sound During Propagation Outdoors, -- Part 2 General Calculation Method. 3 Rickley, E., Fleming, G., & Roof, C. Simplified Procedure for Computing Absorption of Sound by the Atmosphere, Noise Control Engineering, US, 2007 4 American National Standards Institute, ANSI S1-26-1995, American National Standard Method for the Calculation of the Absorption of Sound by the Atmosphere, 1995 5 Menounou, P. A Correction to Maekawa’s Curve for the Insertion Loss Behind Barriers. Journal of Acoustical Society of America, Vol. 101, Issue 4, 2001



TABLE 2 – ACOUSTIC MODELING RESULTS AUGUST 8, 2011

Source Name Description Source Sound

Power Level (dB) at 1.5 meters

Equipment Noise Impact (dBA)

Property Line Nearest Residence

RBA72 Cabinet Equipment Cabinet Climate Control Unit

56.0 21.2 12.2

6.0 RESULTS AND CONCLUSIONS

The predicted noise impact from the AT&T equipment cabinet installation at the Berkeley Mall is 21.2 dBA at the closest property line, and12.2 dBA at the nearest residence (see Table 2). Because of the lack of existing background sound level figures, no real quantitative conclusions about post-construction noise levels can be drawn from these impact values.

7.0 LIMITATIONS

This report was prepared for the use of AT&T. The expressed conclusions of this report apply only to the Berkeley Mall site (CNU1723) and are not applicable to other sites in other locations. The conclusions provided by EBI are based solely on the information pertaining to this site provided by the client. The observations in this report are valid on the date and time of the investigation. Measurement and calculations contained in this report should be considered accurate to within one decibel. Any additional information that becomes available concerning the site should be provided to EBI so that our conclusions may be revised and modified, if necessary. This report has been prepared in accordance with Standard Conditions for Engagement and authorized proposal, both of which are integral parts of this report and has not been designed to address specific noise regulations or ordinances. No other warranty, expressed or implied, is made.



8.0 REVIEWER CERTIFICATION

I, Cynara Cannatella, state that:

I am an employee of Envirobusiness Inc. (d/b/a EBI Consulting), which provides acoustic survey and compliance services to the wireless communications industry. I have reviewed the data pertaining to this site which is incorporated into this Environmental Noise Assessment Report such that the information contained in this report is true and accurate to the best of my knowledge.

Sincerely, By EBI Consulting

Cynara Cannatella Senior Project Engineer



APPENDIX A

EBI - ENVIRONMENTAL NOISE MODEL RESULTS

x y z 32 64 125 250 500 1k 2k 4k 8k 16k

RBA72 Cabinet RBS(N) 24/7 561611.548 4191853.86 8.50 Lw 1.22 20.0 22.9 30.6 48.5 43.8 47.4 51.2 50.5 40.9 56.1 56.0

EBI Consulting ‐ Environmental Noise ModelSound Source DataCNU1723 ‐ Berkeley Mall

Lw/LpOperating

Time

Source Location (UTM) (meters) Source Octave Band Sound Level (dB) Broadband

Level (dB)

Broadband

Level (dBA)IDSource Name

Lp Ref.

Dist. (m)

x y z 32 64 125 250 500 1k 2k 4k 8k 16k

Property Line R(N) 561607.399 4191867.48 1.50 Leq Night 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 7.1

Nearest Residence R(W) 561610.001 4191802.14 1.50 Leq Night 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 7.1

Broadband

Level (dBA)Leq/L90

EBI Consulting ‐ Environmental Noise ModelReceiver Data

CNU1723 ‐ Berkeley Mall

Receiver Name IDReceiver Location (UTM) (meters)

Day/NightReceiver Existing Octave Band Sound Level (dB) Broadband

Level (dB)

7 8 9 10 11 12 13 14 15 16

Dist. Barrier

(m) ID 32 64 125 250 500 1k 2k 4k 8k 16k

Property Line ‐ R(N) ‐ ‐ ‐ ‐ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 7.1

‐ RBA72 Cabinet RBS(N) 15.9 Lw ‐15.0 ‐12.1 ‐4.4 13.5 8.8 12.4 16.2 15.5 5.9 ‐35.5 21.1 21.0

‐ PREDICTED FUTURE LEVEL 0.1 0.3 1.3 13.7 9.3 12.6 16.3 15.6 6.9 0.0 21.4 21.2

Nearest Residence ‐ R(W) ‐ ‐ ‐ ‐ 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 7.1

‐ RBA72 Cabinet RBS(N) 52.2 Lw ‐25.3 ‐22.4 ‐14.8 3.1 ‐1.6 2.1 5.8 5.1 ‐4.7 ‐48.5 10.7 10.6

‐ PREDICTED FUTURE LEVEL 0.0 0.0 0.1 4.8 2.3 4.2 6.8 6.3 1.3 0.0 13.4 12.2

EBI Consulting ‐ Environmental Noise ModelNighttime Sound Level Calculation

CNU1723 ‐ Berkeley Mall

Receiver Name Source Name ID Lp/LwLp Ref.

Dist. (m)

Octave Band Sound Pressure Level (SPL) at Receiver (dB) Broadband SPL

(dB)

Broadband SPL

(dBA)



APPENDIX B

EQUIPMENT SPECIFICATIONS

ACOUSTICAL NOISE SUPPRESSION DATA LOG SHEETSOUND PRESSURE MEASUREMENT SUMMARY

CUSTOMER: MJO:TEST ITEM: DATE:MODEL: UNIT NO:SPECIFICATION: PARA: 3.29 CHAMBER NO:

ACOUSTICAL NOISE SUPPRESSION

Position: 31.5 63.0 125.0 250.0 500.0 1000.0 2000.0 4000.0 8000.0 Laeq1 20.0 20.1 25.3 33.3 32.1 34.0 29.0 20.1 20.0 37.62 20.0 20.1 24.5 33.2 30.6 32.4 28.3 20.0 20.0 36.4

3 20.0 20.0 24.6 31.1 31.4 32.1 28.5 20.0 20.0 36.24 20.0 20.5 24.9 32.3 31.4 32.8 28.3 20.0 20.0 36.8

5 20.0 20.1 24.9 32.5 31.3 33.3 28.2 20.0 20.0 36.66 20.0 20.2 25.0 33.4 30.6 32.0 28.1 20.0 20.0 36.3

7 20.0 20.2 24.6 32.4 32.1 32.5 28.3 20.0 20.0 36.5

8 20.0 20.1 24.9 34.2 31.6 32.9 28.3 20.0 20.0 37.5

Position: 31.5 63.0 125.0 250.0 500.0 1000.0 2000.0 4000.0 8000.0 Laeq1 20.0 23.8 32.8 52.9 47.5 51.0 51.8 53.6 44.9 58.72 20.0 23.4 31.6 51.7 45.8 48.4 50.3 55.7 47.3 58.73 20.0 22.4 30.5 48.1 43.3 46.9 52.3 49.9 40.1 55.94 20.0 22.5 28.9 43.7 41.5 45.6 47.9 44.8 35.0 525 20.0 22.4 29.1 45.9 40.7 45.1 53.5 48.5 37.4 55.6

CommscopeNebs Cabinet 7/21/2010

A10225

RBA72 AT&T Alpha 1 Cabinet ENV 1GR-487-CORE EMI 1

If No or N/A, why?R3-222[157]

Test Results:

CRITERIA

Noise

The EUT is compliant with

the requirement for

GR-487-CORE Acoustical

Background Noise - Sound Pressure Level

(dBA ref 0.0002 microbar)

OCTAVE BAND CENTER FREQUENCY (HZ)

Operating - Sound Pressure Level

OCTAVE BAND CENTER FREQUENCY (HZ)(dBA ref. 0.0002 microbar)

Cabinets, equipped with telecommunications equipment and associated cooling fans, shall suppress acoustical noise to a level of less than 65 dBA at a distance of 1.5 m (5 ft) from the cabinet with the doors closed during times of maximum noise generation within the cabinet.

Note: For cabinets with a permanent generator, this criterion shall be met with the generator not running. With the generator running, the acoustical noise level shall be less than 75 dBA.

Test Procedure - The sound level shall be measured by a sound level meter meeting ANSI 1.4, and set to the A-weighting scale and the slow meter response setting. Measurements shall be made in accordance with ANSI 1.18. For the duration of this test, all equipment fans and any other noise producing equipment shall be operating so that the maximum noise possible is being produced within the cabinet. Cabinet doors shall be closed. Sound levels thus produced shall be measured at 1.5 m (5 ft) from the cabinet surfaces in all horizontal directions at a height of 1 m (3 ft) from the cabinet mounting surface. The background noise must be at least 10 dBA below the measured noise.







Yes No N/AYes No N/AYes No N/A

PLN 21.487.35 Rev. 0 Page 1 of 1

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Environmental Noise Assessment - Berkeley, California · Environmental Noise Assessment Report Site No. CNU1723 EBI Project No. 21110077 1700 Sixth Street, Berkeley, CA ... One RBA72