DATE: July 16, 2024
TO: Jennifer Dorgan, Allen Matkins
FROM: Bill Lawson, Urban Crossroads, Inc.
JOB NO: 16167-02 NA
1313 EAST PHILLIPS ROAD NOISE ASSESSMENT
Jennifer Dorgan,
Urban Crossroads, Inc. is pleased to provide the following Noise Assessment for the 1313 East Phillips Road (Project), which is located in the City of Pomona.
PROJECT OVERVIEW
It is our understanding that the Project site will maintain four existing structures/buildings totaling approximately 39,547 square feet (sf) consisting of a large unenclosed shed and three buildings for administrative support services. The total site area is 472,660 sf, which will encompa ss exterior storage yards. A site plan is presented in Exhibit 1.
SUMMARY OF FINDINGS
The Noise Assessment shows that the Project will not exceed the established City of Pomona operational or construction noise thresholds with nighttime restrictions. Therefore, the Project operational and construction noise impacts are considered less than significant at the nearby noise-sensitive receiver locations.
Attachment No. 11
Jennifer Dorgan, Allen Matkins
July 16, 2024
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EXHIBIT 1: SITE PLAN
Jennifer Dorgan, Allen Matkins
July 16, 2024
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NOISE FUNDAMENTALS
Noise is simply defined as "unwanted sound." Sound becomes unwanted when it interferes with normal activities, when it causes actual physical harm or when it has adverse effects on health.
Noise is measured on a logarithmic scale of sound pressure level known as a decibel (dB). A - weighted decibe ls (dBA) approximate the subjective response of the human ear to broad frequency noise source by discriminating against very low and very high frequencies of the audible spectrum. They are adjusted to reflect only those frequencies which are audible to th e human ear. Exhibit 2 presents a summary of the typical noise levels and their subjective loudness and effects that are described in more detail below.
Since the range of intensities that the human ear can detect is so large, the scale frequently used to measure intensity is a scale based on multiples of 10, the logarithmic scale. The scale for measuring intensity is the decibel scale. Each interval of 10 decibels indicates a sound energy ten times greater than before, which is perceived by the human ea r as being roughly twice as loud. (1) The most common sounds vary between 40 dBA (very quiet) to 100 dBA (very loud). Normal conversation at three feet is roughly at 60 dBA, while loud jet flyover noises equate to 110 dBA at approximately 1,000 feet, which can cause serious discomfort. (2) Another important aspect of noise is the duration of the sound and the way it is described and distributed in time.
EXHIBIT 2: TYPICAL NOISE LEVELS
Jennifer Dorgan, Allen Matkins
July 16, 2024
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RECEIVER LOCATIONS
To assess the potential for noise impacts, the following receiver locations, as shown on Exhibit 3, were identified as representative locations for analysis. Sensitive uses or receivers are generally defined as locations where people reside or where the presence of unwanted sound could otherwise adversely affect the use of the land. To describe the potential off -site Project noise levels, four receiver locations in the vicinity of the Project site were identified, includi ng the location of the nearest existing noise sensitive residential receiver (R3) located approximately 91 feet east of the Project site boundary.
The selection of receiver locations is based on FHWA guidelines and is consistent with additional guidance provided by Caltrans and the FTA. Other sensitive land uses in the Project study area that are located at greater distances than those identified in this noise study will experience lower noise levels than those presented in this report due to the additio nal attenuation from distance and the shielding of intervening structures.
NOISE PREDICTION MODEL
To fully describe the exterior operational noise levels from the Project, Urban Crossroads, Inc. developed a noise prediction model using the CadnaA (Comput er Aided Noise Abatement) computer program. CadnaA can analyze multiple types of noise sources using the spatially accurate Project site plan, georeferenced Nearmap aerial imagery, topography, buildings, and barriers in its calculations to predict outdoor noise levels. Using the ISO 9613-2 protocol, CadnaA will calculate the distance from each noise source to the noise receiver locations, using the ground absorption, distance, and barrier/building attenuation inputs to provide a summary of noise level at each receiver and the partial noise level contributions by noise source. The noise level calculations provided in this noise assessment account for the distance attenuation provided due to geometric spreading, when sound from a localized stationary source (i.e., a point source) propagates uniformly outward in a spherical pattern. A default ground attenuation factor of 0.5 was used in the CadnaA noise analysis to account for mixed ground representing a combination of hard and soft surfaces.
OPERATIONAL NOISE ANALYSIS
This section analyzes the potential stationary -source operational noise impacts at the nearby receiver locations resulting from the operation of the proposed 1313 East Phillips Road Project.
This operational noise analysis is intended to d escribe noise level impacts associated with the typical of daytime and nighttime activities at the Project site. The on -site Project-related noise sources are expected to include storage activity, roof-top air conditioning units, trash enclosure activity, and truck movements.
Jennifer Dorgan, Allen Matkins
July 16, 2024
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EXHIBIT 3: RECEIVER LOCATIONS
Jennifer Dorgan, Allen Matkins
July 16, 2024
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OPERATIONAL NOISE STANDARDS
To analyze noise impacts originating from the 1313 East Phillips Road , operational source noise is evaluated against standards established under a City’s Municipal Code. For noise -sensitive residential property, the City of Pomona Municipal Code, Section 18-311, identifies exterior noise levels standards of 60 dBA L eq for the daytime hours (7:00 a.m. to 10:00 p.m.) and 50 dBA L eq during the nighttime (10:00 p.m. to 7:00 a.m.) hours. The percentile noise descriptors outlined in the municipal code are provided to ensure that the duration of the noise source is fully considered. However, due to the relatively constant intensity of the Project operational activities, the L50 or average Leq noise level metrics best describe the noise source activities. The Leq noise level metric accounts for noise fluctuations over time by energy averaging the louder and quieter events and giving more weight to the louder events. In addition, due to the mathematical relationship between the median (L 50) and the mean (L eq), the L eq will always be larger than or equal to the L 50. In effect, t he more variable the noise becomes, the larger the L eq becomes in comparison to the L50. Therefore, this noise study conservatively relies on the equivalent energy average Leq to describe the Project operational noise levels. The City of Pomona Municipal Code Noise Standards are included in Appendix A.
OPERATIONAL NOISE SOURCES
To estimate the Project operational noise impacts, reference noise level measurements were collected from similar types of activities to represent the noise levels expected wit h the development of the proposed Project. While sound pressure levels (e.g., Leq) quantify in decibels the intensity of given sound sources at a reference distance, sound power levels (L w) are connected to the sound source and are independent of distance . Sound pressure levels vary substantially with distance from the source and diminish because of intervening obstacles and barriers, air absorption, wind, and other factors. Sound power is the acoustical energy emitted by the sound source and is an absol ute value that is not affected by the environment. The reference project operational noise levels are based on the Project related noise source activities shown on Exhibit 4. The reference project operational reference noise levels and sound power levels are summarized below on Table 1.
TABLE 1: REFERENCE NOISE LEVELS
Reference
Noise Source
Noise
Source
Height
(Feet)
Min./
Hour1
Reference
Noise Level
(dBA Leq)
@ 50 Feet
Sound
Power
Level
(dBA)2 Day Night
Storage Activity 8' 60 60 62.8 103.4
Roof-Top Air Conditioning Units 5' 39 28 57.2 88.9
Trash Enclosure Activity 5' 60 30 57.3 89.0
Truck Movements 8' 60 60 59.8 93.2
1 Anticipated duration (minutes within the hour) of noise activity during typical hourly conditions expected at the Project site. "Daytime" = 7:00 a.m. - 10:00 p.m.; "Nighttime" = 10:00 p.m. - 7:00 a.m. 2 Sound power level represents the total amount of acoustical energy (noise level) produced by a sound source independent of distance or surroundings. Sound power levels calculated using the CadnaA noise model at the reference distance to the noise source. Numbers may vary due to size differences between point and area noise sources.
Jennifer Dorgan, Allen Matkins
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EXHIBIT 4: OPERATIONAL NOISE SOURCE LOCATIONS
Jennifer Dorgan, Allen Matkins
July 16, 2024
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OPERATIONAL NOISE LEVEL COMPLIANCE
Using the reference noise levels to represent the proposed Project operations that include storage activity, roof -top air conditioning units, trash enclosure activity, and truck movements , Urban Crossroads, Inc. calculated the operational source noise levels that are expected to be generated at the Project site. Table 2 shows the unmitigated Project operational noise levels during the daytime hours of 7:00 a.m. to 10:00 p.m. The daytime hourly noise levels at the off- site receiver locations are expected to range from 38.8 to 49.3 dBA L eq. The nighttime hourly noise levels at the off-site receiver locations are expected to range from 38.5 to 49.2 dBA Leq. The differences between the daytime and nighttime n oise levels are largely related to the estimated duration of noise activity with n o nighttime pickleball activities as outlined in Table 1 and Appendix B.
TABLE 2: OPERATIONAL NOISE LEVEL COMPLIANCE
Project Operational
Noise Levels (dBA Leq)2
Noise Level Standards
(dBA Leq)3
Noise Level Standards
Exceeded?4
Daytime Nighttime Daytime Nighttime Daytime Nighttime
R1 46.4 46.3 60 50 No No
R2 49.3 49.2 60 50 No No
R3 48.9 48.9 60 50 No No
R4 38.8 38.5 60 50 No No
R5 46.8 46.8 60 50 No No
1 See Exhibit C for the receiver locations.
2 Project operational noise calculations are included in Appendix B. 3 City of Pomona Municipal Code Section 18-311 Exterior noise level standards. 4 Do the estimated Project operational noise source activities exceed the noise level standards? 5 Project operational noise levels provided for informational purposes "Daytime" = 7:00 a.m. - 10:00 p.m.; "Nighttime" = 10:00 p.m. - 7:00 a.m.
Table 2 shows that the unmitigated operational noise levels associated with 1313 East Phillips Road Project will not exceed the City of Pomona exterior noise level standards.
CONSTRUCTION NOISE ANALYSIS
This section analyzes potential impacts resulti ng from the short -term construction activities associated with the development of the Project. The City of Pomona Municipal Code, Section 18- 305[3] establishes the permitted hours during which construction within the City of Pomona may take place, between 7:00 a.m. to 8:00 p.m. on weekdays and Saturdays, with no activity allowed on Sundays and Holidays. In addition, Section 18 -305[3] indicates that the noise levels due to construction activity may not exceed 65 dBA Leq.
To describe construction noise activities, this construction noise analysis was prepared using reference construction equipment noise levels from the Federal Highway Administration (FHWA) published the Roadway Construction Noise Model (RCNM), which includes a national database of construction equipment reference noise emission levels. (3) Using a composite reference noise level of 86.8 dBA Leq at 50 feet to describe Project construction equipment activities, calculations Jennifer Dorgan, Allen Matkins
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of the Project construction noise level impacts at the nearby sensitive receiver locations were completed using the CadnaA noise prediction model. As shown on Table 3, the highest construction noise levels are expected to range from 50.9 to 56.9 dBA Leq at the nearby receiver locations. Appendix C includes the detailed CadnaA construction noise model inputs. The construction noise analysis shows that the nearest receiver locations will not exceed the 65 dBA Leq significance threshold during Project construction activities as shown on Table 3.
TABLE 3: CONSTRUCTION NOISE LEVEL COMPLIANCE
Receiver
Location1
Construction Noise Levels (dBA Leq)
Highest Construction
Noise Levels2 Threshold3 Threshold
Exceeded?4
R1 52.7 65 No
R2 50.4 65 No
R3 49.1 65 No
R4 59.1 65 No
1 Receiver locations are shown on Exhibit C.
2 Construction noise level calculations included in Appendix C. 3 City of Pomona Municipal Code Section 18-305[3].
4 Do the estimated Project construction noise levels exceed the construction noise level threshold?
OFF-SITE TRAFFIC ANALYSIS
Traffic generated by the operation of the proposed Project will influence the traffic noise levels in surrounding off-site areas and at the Project site. However, the off -site Project-related traffic represents an incremental increase to the existing road way volumes, which is not expected to generate a barely perceptible noise level increase of 3 dBA CNEL at nearby sensitive land uses adjacent to study area roadways, since a doubling of the existing traffic volumes would be required to generate a 3 dBA CNE L increase. According to the 1313 East Phillips Road Vehicle Miles Traveled (VMT) Screening Evaluation, (4) the Project is anticipated to generate a net total increase of 108 two-way trips per day (actual vehicles). The incremental Project -related off-site traffic noise levels due to the 1313 East Phillips Road project trips are estimated at less than 1 dBA CNEL. Therefore, due to the low traffic volumes generated by the P roject, the off-site traffic noise levels generated by the Project are considered less than significant and no further analysis is required.
Jennifer Dorgan, Allen Matkins
July 16, 2024
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CONCLUSIONS
This Noise Assessment demonstrates that the noise levels associated with 1313 East Phillips Road Project will not exceed the established operational or construction noise thresholds at the nearest residential receiver locations. Therefore, the project related noise impacts are considered less than significant at the nearby noise -sensitive receiver lo cations. If you have any questions, please contact me directly at (949) 584-3148.
REFERENCES
1. California Department of Transportation Environmental Program. Technical Noise Supplement - A Technical Supplement to the Traffic Noise Analysis Protocol. Sacramento, CA : s.n., September 2013.
2. Environmental Protection Agency Office of Noise Abatement and Control. Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety. March 1974. EPA/ONAC 550/9/74-004.
3. U.S. Department of Transportation, Federal Highway Administration, Office of Environment and Planning. FHWA Roadway Construction Noise Model. January, 2006.
4. Urban Crossroads, Inc. 1313 East Phillips Road Vehicle Miles Traveled (VMT) Screening Evaluation.
July 2024.
5. City of Pomona. Municipal Code, Article VII - Noise and Vibration Control.
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ATTACHMENT A
CITY OF POMONA MUNICIPAL CODE ARTICLE VII
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ATTACHMENT B
OPERATIONAL NOISE MODEL CALCULATIONS
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ATTACHMENT C
CONSTRUCTION NOISE MODEL CALCULATIONS
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