HomeMy WebLinkAboutNoise Analysis
July 3, 2018 11040-7266
Tori Massie
Baldwin & Sons
Project Coordinator
610 West Ash, Suite 1500
San Diego, California 92101
Subject: PA-12 East – Addendum to Prior Noise Study
Dear Ms. Massie:
Dudek has completed this focused noise re-assessment for the Otay Ranch Freeway Commercial
Sectional Planning Area (SPA) Plan – Planning Area 12 (PA-12), in the City of Chula Vista,
California. This letter specifically addresses the East portion of the PA-12 development,
specifically east of Town Center Drive. At your request, we have re-evaluated the adjacent
roadway traffic noise and BRT noise based upon current site information. Please note that all
sound levels in this report are A-weighted. Definitions of acoustical terms used in this report are
provided in Attachment 1.
CITY NOISE CRITERIA
The City of Chula Vista General Plan Noise Element indicates that the maximum allowable
exterior noise level for new residential developments is a Community Noise Equivalent Level
(CNEL) of 65 A-weighted decibels (dBA) (City of Chula Vista 2005). California Building Code
(Part 2, Title 24, California Code of Regulations) requires that the interior noise level attributable
to exterior noise sources not exceed 45 dBA CNEL for multi-family residential buildings.
The City of Chula Vista also requires that interior noise levels attributable to exterior noise
sources not exceed a CNEL of 45 dBA within residences. Typically, with the windows open,
building shells provide approximately 15 dBA of noise reduction. Therefore, rooms exposed to
an exterior CNEL greater than 60 dBA could result in an interior CNEL greater than 45 dBA.
The California Building Code recognizes this relationship and therefore requires interior noise
studies when the exterior noise level is projected to exceed 60 dBA CNEL.
METHODOLOGY
The exterior noise analysis follows the same general procedure outlined in Noise Assessment
Technical Report for the Otay Ranch Freeway Commercial Sectional Planning Area (SPA)
Ms. Tori Massie
Subject: PA-12 East – Addendum to Prior Noise Study
11040-7266
2 July 2018
Plan – Planning Area 12 (PA-12). Average Daily Traffic (ADT) data for the adjacent arterial
roadways was input in a computer model along with topographical data and site plan
information. CadnaA (Computer Aided Noise Abatement) is a software program for calculation,
presentation, assessment and prediction of environmental noise. This program was used to build
an updated exterior noise model for the project specific area.
For the updated modeling, the more detailed site plan provided by the applicant was utilized for
the analysis. Figure 1 shows the location of the modeled receiver based on these updated plans.
TRAFFIC NOISE
Olympic Parkway and Eastlake Parkway make up the northern and eastern boundaries of the site.
These two roads are the focus of the traffic noise modeling update. The posted speed on Olympic
Parkway is 50 mph (80 kmh). This speed was assumed for both Olympic Parkway and Eastlake
Parkway. Table 1 shows the traffic data used for the noise model.
Table 1
Traffic Volumes Associated with Local Roadways Segments
Road Segment Existing ADT
Existing + Project
ADT Horizon Year ADT
Horizon Year +
Project ADT
Olympic Parkway 35,608 39,310 48,000 51,700
Eastlake Parkway 12,092 13,030 23,660 24,600
Source: Chen Ryan. 2015
Utilizing the most recent plan sets and grading elevatio ns available for the mixed use product
types currently planned for the site, we refined a traffic noise model in CadnaA for the
project. The same traffic volumes as used in the prior noise Addendum (Dudek 2015) were
utilized for this analysis – specifically, the Horizon Year future traffic volumes as provided
by Chen Ryan (Chen Ryan 2015), because these volumes are still current (i.e., there have
been no revised projections).
Modeled receiver points were placed at the proposed poolside location, the parklet, and other
outdoor areas as well as balcony areas, as shown in Figure 1. Receiver heights corresponding to
1st, 2nd, 3rd and 4th floor elevations were modeled for balconies, based on the provided plans
(Baldwin and Sons 2018). The planned pool area was also incorporated into the updated model.
Table 2 and Table 3 show the updated calculated exterior traffic noise levels. To place the
reported exterior noise levels in context, where noise levels exceed 65 A-weighted decibels
(dBA) Community Noise Equivalent Level (CNEL), exterior mitigation is required; At locations
Ms. Tori Massie
Subject: PA-12 East – Addendum to Prior Noise Study
11040-7266
3 July 2018
where exterior noise levels exceed 60 dBA CNEL, interior analysis is required. Numbers
displayed in bold indicate where levels exceed 65 dBA CNEL, and italicized numbers indicate
where levels exceed 60 dBA CNEL.
Table 2
Summary of On-Site Traffic Noise Levels1 (dBA CNEL) at Outdoor Use Locations
Receiver Name Existing
Existing Plus
Project Horizon
Horizon Year
Plus Project
M1 Parklet / Fire Access 65 65 68 68
M2 Outdoor Corridor Area 54 54 56 56
M3 Area Amenities North Patio (Playground) 65 65 66 67
Notes:
Bold = noise level exceeds 65 dBA CNEL Standard for exterior noise.
Italics = noise level exceeds 60 dBA CNEL, indicating that the interior noise standard could be exceeded.
Table 3
Summary of On-Site Traffic Noise Levels (dBA CNEL) at Balconies
Receiver Location
On Map Floor (Level) Existing Existing Plus Project Horizon
Horizon Year Plus
Project
A1 F1 65 66 66 67
A1 F2 61 62 63 63
A1 F3 61 61 62 62
A1 F4 61 61 62 63
A2 F1 61 62 63 63
A2 F2 61 62 63 63
A2 F3 61 62 62 63
A2 F4 61 62 62 63
A3 F1 63 64 65 65
A3 F2 63 64 64 65
A3 F3 61 62 63 63
A3 F4 61 62 63 63
A4 F1 67 68 69 69
A4 F2 64 64 65 65
A4 F3 62 62 63 63
A4 F4 62 62 63 63
A5 F1 65 65 66 66
A5 F2 63 64 65 65
A5 F3 62 63 63 64
A5 F4 62 62 63 63
A6 F1 66 67 67 68
A6 F2 63 63 64 65
A6 F3 62 62 63 64
A6 F4 62 62 63 63
Ms. Tori Massie
Subject: PA-12 East – Addendum to Prior Noise Study
11040-7266
4 July 2018
Table 3
Summary of On-Site Traffic Noise Levels (dBA CNEL) at Balconies
Receiver Location
On Map Floor (Level) Existing Existing Plus Project Horizon
Horizon Year Plus
Project
A7 F1 66 67 68 68
A7 F2 63 63 64 64
A7 F3 62 62 63 63
A7 F4 62 62 63 63
A8 F1 67 67 68 69
A8 F2 62 63 64 64
A8 F3 62 62 63 63
A8 F4 61 62 63 63
B1 F1 64 64 65 66
B1 F2 65 65 66 66
B1 F3 62 62 63 63
B1 F4 61 62 63 63
B2 F1 67 68 69 69
B2 F2 63 63 64 64
B2 F3 61 62 63 63
B2 F4 61 62 62 63
B3 F1 66 67 67 68
B3 F2 62 63 64 64
B3 F3 61 62 63 63
B3 F4 61 62 63 63
B4 F1 65 66 67 67
B4 F2 62 62 63 63
B4 F3 61 62 63 63
B4 F4 61 62 63 63
B5 F1 64 65 66 66
B5 F2 62 62 63 63
B5 F3 61 62 62 63
B5 F4 61 62 62 63
B6 F1 69 69 70 70
B6 F2 62 62 63 63
B6 F3 62 62 63 63
B6 F4 61 62 63 63
B7 F1 68 69 70 70
B7 F2 62 62 63 64
B7 F3 62 62 63 63
B7 F4 62 62 63 63
B8 F1 56 57 58 58
B8 F2 61 62 63 63
B8 F3 61 62 63 63
B8 F4 61 61 62 63
B9 F1 48 48 50 50
Ms. Tori Massie
Subject: PA-12 East – Addendum to Prior Noise Study
11040-7266
5 July 2018
Table 3
Summary of On-Site Traffic Noise Levels (dBA CNEL) at Balconies
Receiver Location
On Map Floor (Level) Existing Existing Plus Project Horizon
Horizon Year Plus
Project
B9 F2 59 60 62 62
B9 F3 61 61 62 62
B9 F4 60 61 62 62
B10 F1 61 61 63 63
B10 F2 60 60 62 62
B10 F3 61 61 63 63
B10 F4 61 61 63 63
B11 F1 54 55 57 57
B11 F2 56 56 58 59
B11 F3 58 58 61 61
B11 F4 58 59 61 61
Notes:
Bold = noise level exceeds 65 dBA CNEL Standard for exterior noise.
Italics = noise level exceeds 60 dBA CNEL, indicating that the interior noise standard could be exceeded.
Balcony barriers. For exterior noise levels at the multi-family residential buildings, the Otay
Ranch GDP has policies in place to require appropriate sound attenuation project features for all
required residential open space and public open space areas that are exposed to a noise level of
65 dBA CNEL or greater. Consistent with these policies, balconies planned on these residential
units that are counted as part of an open space requirement would need to incorporate
appropriate sound attenuating project features around the perimeter of the balconies so as not to
exceed the 65 dB CNEL threshold.
Based upon the data shown in Table 3, building receptors A1, A4, A5, A6, A7, A8, B1, B2, B3,
B4, B5, B6, and B7 at first-floor balconies/open space areas and B1 at the second floor balcony
would require Plexiglass or other clear-view panels within the line-of-sight of Olympic Parkway
if the balconies/open space areas are being used to satisfy the project’s open space requirement.
The height of such panels should be a minimum of 6 feet, in order to ensure a minimum noise
reduction of 5 decibels.
Noise wall. Based upon the data shown in Table 2, the ground -floor level exterior common
areas (Parklet and Northern Patio Ame nity Area) within the line-of-sight of Olympic Parkway
and Eastlake Parkway would require noise attenuation in the form of noise barriers. The height
of such panels should be a minimum of 6 feet, in order to ensure a minimum noise reduction of
5 decibels. The noise barrier would be extended along Eastlake Parkway as shown in Figure 1
for the parklet . For the Northern Patio Amenity Area, the wall would need to be positioned as
shown in Figure 1.
Ms. Tori Massie
Subject: PA-12 East – Addendum to Prior Noise Study
11040-7266
6 July 2018
The noise barriers should have a surface density of at least four pounds per square foot and be
free of openings and cracks (with the exception of expansion joints gaps and other construction
techniques, which could create an opening or crack). The noise barriers may be constructed of
acrylic glass, masonry material, earthen berm, or a combination of these materials.
With construction of a solid noise barrier between the Parklet and Eastlake Parkway, and the
Northern Patio Amenity Area and Olympic Parkway, exterior noise impacts would be less
than significant.
Interior Noise. Based upon Table 2, traffic noise levels would exceed 60 dB CNEL for
residential units facing Olympic Parkway. These units/floors will require subsequent acoustical
analyses to verify compliance with the state of California (CCR Title 24) and City of Chula Vista
45 dB CNEL interior noise standard.
NOISE FROM BUS RAPID TRANSIT (BRT) LINE
As discussed in a prior noise study for the project (Dudek, 2015), the South Bay Bus Rapid
Transit (BRT) route will be located along the future extension of East Palomar Street adjacent to
the southern boundary of the project site. Noise sensitive receptors that would be affected by the
South Bay Bus Rapid Transit project that would extend East Palomar Street along the southern
portion of the project site include the multi-family residential buildings on the southwest portion
of the PA-12 site. Previous noise modeling based on methodology identified by the Federal
Transit Authority (FTA 2006) and utilizing the FHWA TNM 2.5 traffic noise model (FHWA)
was conducted to determine the noise level associated with the South Bay Bus Rapid Transit
project on a separate portion of Otay Ranch. It was determined that at a distance of 40 feet from
the centerline of the nearest side of East Palomar Street the buildings would experience a
maximum future noise level of 64 dB CNEL at the first floor.
Based upon recently discovered noise emission levels used for the South Bay Bus Rapid Transit
Project (Kimley-Horn and Associates, 2012), the BRT line is anticipated to result in 60 dB
CNEL at a distance of 50 feet. This would equate to a 65 dB CNEL at a distance of 28 feet from
the BRT centerline. Providing that the nearest residential units are not located within 28 feet of
the BRT centerline, the exterior use areas (patios or balconies) would not exceed the City’s
exterior noise standard. Additionally, residential units within 50 feet of the BRT centerline
would require subsequent acoustical analysis to verify compliance with the state of California
(CCR Title 24) and the City of Chula Vista 45 dB CNEL interior noise standard. Based upon the
current site plans, none of the buildings in the PA-12 east portion of the site are located within 50
feet of the BRT centerline. Therefore, noise impacts from the BRT line would be less than
significant. No noise mitigation would be required for the BRT line noise.
Ms. Tori Massie
Subject: PA-12 East – Addendum to Prior Noise Study
11040-7266
7 July 2018
MITIGATION
1. Consistent with Mitigation Measure 5.5-1 of the approved EIR (City of Chula Vista
2002), and to comply with the City and State’s 45 dB CNEL interior noise standard, the
following mitigation measure is required:
a. Prior to the approval of site development plans, the applicant shall submit a
supplemental noise analysis acceptable to the Director of Planning and Building
demonstrating that interior noise levels would not exceed 45 dB CNEL.
b. A noise barrier with a minimum height of 6 feet shall be constructed along the eastern
edge of the site next to Eastlake Parkway, unless that proposed open space area is not
needed to meet the project’s exterior open space requirement. Figure 1 shows the
location of the barrier.
c. A noise barrier with a minimum height of 6 feet shall be constructed (as shown in Figure
1) to block the noise from Olympic Parkway from the Northern Patio Amenity Area.
d. Building receptors A1, A4, A5, A6, A7, A8, B1, B2, B3, B4, B5, B6, and B7 would
require Plexiglass or other clear-view panels at first-floor balconies/open space areas
within the line-of-sight Olympic Parkway if the balconies/open space areas are used
to satisfy the project’s open space requirement.
This completes this focused noise report for the PA-12 East project. Should you have any
questions regarding the above information, please call me at 760.479.4248.
Sincerely,
________________________
Brian Grover
Environmental Specialist/Project Manager
bgrover@dudek.com
760.479.4248
__________________________________
Christopher Barnobi, INCE Bd.Cert.
Environmental Acoustician
cbarnobi@dudek.com
Att.: Figure 1
Attachment 1 – Definitions
Ms. Tori Massie
Subject: PA-12 East – Addendum to Prior Noise Study
11040-7266
8 July 2018
REFERENCES
Chen Ryan. 2015. Otay Ranch PA 12 – Trip Generation Review. February 12.
City of Chula Vista. 2002. Otay Ranch Planning Area 12 EIR – Freeway Commercial.
“Section 5.5 – Noise.”
City of Chula Vista. 2005. City of Chula Vista General Plan. “Chapter 9 Noise Element.”
December 13.
Dudek. 2015. PA-12 FC-2 Amendment Acoustical Assessment Report. March 20, 2015.
FHWA (Federal Highway Administration). 2004. FHWA Traffic Noise Model User’s Guide
(Version 2.5 Addendum). April.
Kimley-Horn and Associates, Inc. 2012. Draft Noise Analysis Report, South Bay Bus Rapid
Transit. Prepared for San Diego Association of Governments. December 2012.
B11B11
B10B10
M1M1
B9B9
B1B1 B2B2 B3B3 B4B4 B5B5
B6B6 B7B7
A2A2
A3A3
A4A4 A5A5 A6A6
A7A7
A8A8
A1A1
M5M5
M3M3
M4M4
M2M2
B8B8
Noise Measurement Locations and Proposed Soundwall
PA-12 Exterior Noise Study
FIGURE 1SOURCE: Baldwin &Sons 2018
Pa
t
h
:
Z
:
\
P
r
o
j
e
c
t
s
\
j
1
1
0
4
0
0
1
\
M
A
P
D
O
C
\
N
o
i
s
e
ATTACHMENT 1
Definitions
ATTACHMENT 1
Definitions
11040-7266
1-1 July 2018
Term Definition
Ambient Noise Level The composite of noise from all sources near and
far. The normal or existing level of environmental
noise at a given location.
A-Weighted Sound Level, (Dba) The sound pressure level in decibels as measured on
a sound level meter using the A-weighted filter
network. The A-weighting filter de-emphasizes the
very low and very high frequency components of
the sound in a manner similar to the frequency
response of the human ear and correlates well with
Community Equivalent CNEL is the A-weighted equivalent continuous
Sound Level (CNEL) sound exposure (CNEL) level for a 24-hour period
with a 10 dB adjustment added to sound levels
occurring during the nighttime hours (10 p.m. to 7
a.m.) and 5 dB added to the sound during the
evening hours (7 p.m. to 10 p.m.).
Decibel, (dB) A unit for measuring sound pressure level and is
equal to 10 times the logarithm to the base 10 of the
ratio of the measured sound pressure squared to a
reference pressure, which is 20 micropascals.
Time-Average Sound Level The sound level corresponding to a steady state
level containing the same total energy as a time
varying signal over a given sample period. TAV is
designed to average all of the loud and quiet sound
levels occurring over a time period.
ATTACHMENT 1 (Continued)
11040-7266
1-2 July 2018
INTENTIONALLY LEFT BLANK