2.3_Chapter 2.3 - NoiseSection 2.3
Noise
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-1
May 2013
2.3 NOISE
This section presents an assessment of potential noise impacts associated with the proposed
Project. The evaluation addresses potential noise and vibration created during the construction of
the Project and operational noise from the widened roadway on adjacent noise-sensitive land uses.
The analysis is based on information contained within the Noise Study Report (included as
Appendix B of this EIR) prepared for the Project by HELIX (2011).
Noise criteria and policies established in the City General Plan Noise Element (1991a) and
Municipal Code, as well as Section 216 of the California Streets and Highways Code are followed
in this section. These standards establish procedures for noise studies regarding traffic noise
prediction, noise analyses and noise abatement criteria.
2.3.1 Affected Environment
Noise Descriptors
Sound (noise) levels are measured in decibels (dB). Community noise levels are typically
measured in terms of A-weighted decibels (dBA). The A-weighted scale measures noise levels
generally corresponding to the human hearing frequency response. All sound levels in this EIR are
A-weighted.
In general, vehicular noise levels increase with speed. Assuming that traffic speeds remain the
same, increased traffic volumes also can increase traffic noise. In general, with traffic moving at
the same speed, it takes a doubling of the traffic volume to increase noise levels by three dBA.
Sound propagation (i.e., the passage of sound from a noise source to a receiver) is influenced by
several factors. The manner in which noise reduces with distance depends on several factors,
including geometric spreading and ground absorption, as well as shielding by natural and human-
made features. In general, the greater the distance the receiver is situated from the road, the greater
the potential for variation in noise levels due to the atmospheric effects. Additional noise
attenuation can result from human-made features, such as buildings and walls, as well as natural
features, such as hills and dense vegetation, which can reduce traffic noise by shielding the receiver
from the road. Atmospheric effects also can influence traffic noise. These effects include wind,
temperature gradients, and humidity.
Additional units of measurement have been developed to evaluate the long-term characteristics of
sound. The equivalent sound level (Leq), also referred to as time-average sound level, is a single
number representing fluctuating sound level in dB over a specified period of time (e.g., one
minute, 10 minutes, one hour). The Leq also is used to determine the Community Noise Equivalent
Level (CNEL) used by the City to describe community noise levels. CNEL is a weighted 24-hour
average sound level (i.e., the sound-energy average value of 24 hourly Leq after applying a 5-dB
“penalty” to noise levels from 7:00 p.m. to 10:00 p.m. and a 10-dB penalty from 10:00 p.m. to
7:00 a.m.). The 5- and 10-dB penalties are applied to account for increased sensitivity of people
exposed to noise during the evening and nighttime hours.
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-2
May 2013
Methodologies and Instrumentation
To determine existing noise levels and provide the basis for identification of potential noise
impacts, a noise monitoring survey was conducted along the Project alignment. Although all
developed land uses were evaluated in the Noise Study Report, noise abatement was only
considered for areas of frequent human use that would benefit from a lowered noise level
(i.e., outdoor activity areas, such as residential backyards and institutional open space areas).
Noise measurements were conducted using a Larson-Davis Laboratories Model 700 (S.N. 2132)
integrating sound level meter equipped with a Type 2551 0.5-inch pre-polarized condenser
microphone with pre-amplifier. When equipped with this microphone, the sound level meter
meets the current American National Standards Institute Standard for a Type 1 (precision) sound
level meter. The sound level meter was calibrated before and after each measurement and the
measurements were conducted with the microphones positioned five feet above the ground level.
The traffic model used is the Traffic Noise Model (TNM) software Version 2.5, specifically
developed to assess noise related to roadways. TNM calculates the daytime average Hourly Noise
Level (HNL) from three-dimensional model inputs and traffic data. The TNM models used in this
analysis were developed from the project planning Computer Aided Design (CAD) model features,
including road alignment, elevation, lane configuration, area topography, existing and planned
noise control features, projected traffic volumes, estimated truck composition percentages, and
vehicle speeds.
Traffic noise was evaluated under existing conditions, design-year No Project conditions and
design-year conditions with the proposed Project. Loudest-hour (peak) traffic volumes, vehicle
classification percentages, and traffic speeds under existing and design-year (2030) conditions
were provided by the Project traffic engineer (KOA Corporation 2006). The loudest hour is
generally characterized by free-flowing traffic at the roadway design speed (i.e., generally
equivalent to LOS C or better). The analysis for the Noise Study Report is based on these peak
traffic volumes at the roadway maximum potential future speed of 45 miles per hour. The truck
percentage used in the noise model for the loudest (peak) hour average sound level was 1.9 percent
medium trucks and 0.2 percent heavy trucks. Espola Road is restricted to vehicles weighing
20,000 pounds or less, which restricts the amount of truck traffic. Estimated truck composition
percentages used in the noise model are based on the traffic mix counted during on-site noise
measurements; the truck mix is assumed to remain the same in the future.
TNM 2.5 was used to compare measured traffic noise levels to modeled noise levels at noise
measurement locations in order to validate the accuracy of the model. For each receiver, traffic
volumes counted during the short-term measurement periods were normalized to one-hour
volumes. These normalized volumes were assigned to simulate the noise source strength during
the actual measurement period. Modeled and measured sound levels were then compared to
determine the accuracy of the model and if additional calibration of the model was necessary.
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-3
May 2013
Existing Noise Levels
In order to ensure that modeling would reflect real-world conditions, noise measurements were
completed at a number of site locations. These included actual sound measurement, as well as
counting of vehicle numbers and types passing by the location. The existing readings were then
compared with projected sound levels generated through modeling of counted vehicular numbers,
existing topography, and measurement location (shown in Table 2.3-1, Measured Average Noise
Level and Concurrent Traffic Volumes).1
Table 2.3-1
MEASURED AVERAGE NOISE LEVEL AND
CONCURRENT TRAFFIC VOLUMES
Site Description Date/Time Leq2 Cars MT3 HT4
M11
South of Twin Peaks Road
approximately 50 feet to
centerline of Espola Road
October 31, 2002/
1:40 - 2:00 p.m. 66 dBA 253 3 2
M2
West of Mountain Road
approximately 45 feet to
centerline of Espola Road
October 18, 2002/
10:20 - 10:40 a.m. 66 dBA 213 7 2
M3
South of Del Poniente Road
approximately 45 feet to
centerline of Espola Road
October 31, 2002/
4:00 - 5:00 p.m. 66 dBA 1,834 36 3
M4
South of North Crest Lane
approximately 75 feet to
centerline of Espola Road
October 18, 2002/
11:20 - 11:40 a.m. 54 dBA 229 5 0
M5
North of Twin Peaks Road
approximately 70 feet to
centerline of Espola Road
October 18, 2002/
10:45 - 11:05 a.m. 63 dBA 262 8 2
M6
Montessori Child
Development Center
approximately 150 feet to
centerline of Espola Road
October 18, 2002/
9:40 - 10:00 a.m. 56 dBA 250 7 2
M7
South of Eden Grove
approximately 95 feet to
centerline of Espola Road
October 31, 2002/
2:55 - 3:15 p.m. 64 dBA 541 7 1
1 This technical effort ensures that when noise projections are made, appropriate and accurate data have been
integrated into the model (if modeling does not match the existing, real-world measurements, the model is
adjusted until it does match existing parameters). The actual date of original modeling is not relevant to ultimate
projections, because those projections do not incorporate existing sound levels and then add on to them, but
rather “stand on their own.” In other words, given details about assumed traffic mix, traffic numbers and time of
day, combined with details as to planned road elevational changes due to grading, changes in lane configuration,
and location of sensitive receptors, the model will accurately project future conditions.
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-4
May 2013
Table 2.3-1 (cont.)
MEASURED AVERAGE NOISE LEVEL AND
CONCURRENT TRAFFIC VOLUMES
Site Description Date/Time Leq2 Cars MT3 HT4
BG1
Approximately 50 feet to
centerline of Durhullen Drive
and 0.25 mile west of site
October 31, 2002/
3:30 - 3:50 p.m. 51 dBA 28 0 0
BG2
Approximately 50 feet to
centerline of Twin Peaks and
0.25 mile west of site
November 13, 2002/
7:05 - 7:35 a.m. 70 dBA 808 18 5
Source: Pacific Noise Control 2004
Notes: 1 Refer to Figure 2.3-1 for a graphic depiction of noise monitoring locations M1 through M7.
2 Equivalent continuous A-weighted sound pressure level
3 Medium trucks
4 Heavy trucks
Short-term noise measurements were made at nine locations. Noise measurements were conducted
for periods of 20 to 60 minutes adjacent to the road at seven locations (designated as Sites M1
through M7 on Figure 2.3-1, Noise Measurement and Noise Receiver Locations). Two
background noise measurements were conducted outside the Espola Road corridor to determine the
contribution of traffic noise to the existing noise levels. Additionally, one long-term noise
measurement was taken over the course of one full day.
The measured noise levels at Sites M1 through M7 varied from 54 to 66 dBA Leq. The results of
the noise level measurements and corresponding traffic counts are depicted in Table 2.3-1.
Background noise measurements were conducted approximately 50 feet from the centerlines of
Durhullen Drive and Twin Peaks Road (Sites BG1 and BG2, respectively, in Table 2.3-1),
approximately 0.25 mile west of the Project site. Background noise levels generally range from
approximately 45 to 50 dBA within residential areas located approximately 0.25 mile from the
Project site. The noise level was approximately 50 dBA Leq along Durhullen Drive (a two-lane
local collector) and the noise level was approximately 70 dBA Leq along Twin Peaks Road (a four-
lane major arterial).
In addition to short-term noise measurements, a single long-term measurement site (Site A) was
selected to capture the diurnal traffic noise level pattern in the Project area and provide an
unobstructed view of the road (i.e., no intervening walls, buildings, vegetation, etc.). The purpose
of this noise measurement was to determine the typical peak loudest hour Leq associated with
traffic along Espola Road and the corresponding relationship between the loudest hour and CNEL.
The predicted sound levels were within two dBA of the measured sound levels and were, therefore,
considered to be in reasonable agreement with the measured sound levels. As such, no additional
calibration of the model was required.
!9
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Twin Peaks Road
Mtn Road
Northcrest Lane
Titan Way
Del Poniente Road
Huntington Gate Drive
Tierra Bonita Road
Eden Grove
Via Molinero
Golden Sunset Lane
Derringer Road
Carlson Street
Kalapana Street
Jerome Drive
Roberto Rio Road
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Crestview Court
Durhullen Drive
Rio Court
Mesquite Tree
Evergreen Lane
El Topo Drive
Los Nietos Avenue
Segundo Court
Carnitas StreetEl Dolora Way
H i g h V a l l e y R o a d
Saddlebrook Court
Alando Place
Espola Road
Willow Ranch Road
Job No: BAH-01 Date: 12/22/11
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Figure 2.3-1
ESPOLA ROAD IMPROVEMENT PROJECT
Noise Measurement and Noise Receiver Locations
LEGEND
!A
!1 Noise Receiver Location
Short-term Background Noise Measurement Location
Long-term Noise Measurement Location
Short-term Noise Measurement Location
!BG1
!M1
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-5
May 2013
Regulatory Setting
State
Section 216 of the California Streets and Highways Code
Section 216 of the California Streets and Highways Code relates to roadway noise effects on
public and private elementary and secondary schools. Under this code, a noise impact would
occur if, as a result of a proposed project, noise levels would exceed 52 dBA Leq(h) in the interior
of public or private elementary or secondary classrooms, libraries or multi-purpose rooms or
spaces.
If a project results in a noise impact under this code, noise abatement must be provided to reduce
classroom noise to a level that is at or below 52 dBA Leq(h). If the noise levels generated from
freeway and non-freeway sources exceed 52 dBA Leq(h) prior to the construction of the proposed
freeway project, then noise abatement must be provided to reduce the noise to the level that existed
prior to construction of the project.
City of Poway
City of Poway General Plan
To facilitate implementation of noise abatement measures, the City uses the following general
noise abatement guidelines for residential areas next to existing arterials for road improvement
projects:
1. When improvements to arterials are constructed in developed areas where the existing
noise level is below 60 dB CNEL, noise levels will be mitigated to 60 dB CNEL
provided a noise attenuation wall does not exceed eight feet. If the proposed noise
attenuation wall exceeds eight feet, the City will strive to reduce noise to the best
practical level.
2. In areas where the existing noise level exceeds 65 dB CNEL, the noise level will be
mitigated to 65 dB CNEL.
Although not specifically stated in the City’s General Plan, the City also will strive to reduce
noise levels to 60 dB CNEL in areas where the existing noise level is between 60 and 65 dB
CNEL. In identifying noise impacts, primary consideration is given to exterior areas of frequent
human use. The noise abatement criteria for outdoor noise exposure typically are applied at the
backyards of single-family homes.
City of Poway Municipal Code
Noise-generating sources in the City are regulated under Chapter 8.08, Noise Abatement and
Control, of the PMC. PMC Section 8.08.100 restricts the allowable hours of construction
activities to 7:00 a.m. through 7:00 p.m., Monday through Saturday, excluding legal holidays.
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-6
May 2013
This ordinance states that the operation of any single or combined powered construction
equipment is prohibited before 7:00 a.m. or after 5:00 p.m. on Mondays through Saturdays or at
any time on a Sunday or holiday, except as permitted by the City Engineer. Further, the noise
levels associated with construction activities at residential properties are not to exceed 75 dBA,
averaged over an eight-hour period per day. Equipment noise levels must comply with the limits
over various durations as shown in Table 2.3-2, City of Poway Noise Requirements.
Table 2.3-2
CITY OF POWAY NOISE REQUIREMENTS
Total Duration in 24 Hours Total Decibel Level
Up to 15 minutes 90
Up to 30 minutes 87
Up to 1 hour 84
Up to 2 hours 81
Up to 4 hours 78
Up to 8 hours 75
Source: City PMC Chapter 8.08
2.3.2 Thresholds of Significance
The Project would result in significant impacts associated with noise if it would:
Expose persons to or generation of noise levels in excess of standards established in the
local general plan or noise ordinance, or applicable standards of other agencies.
Expose persons to or generation of excessive groundborne vibration or groundborne
noise levels.
Result in a substantial permanent increase in ambient noise levels in the Project vicinity
above levels existing without the Project.
Result in a substantial temporary or periodic increase in ambient noise levels in the
Project vicinity above levels existing without the Project.
2.3.3 Impacts
Construction Impacts
During construction of the Project, noise from construction activities may intermittently dominate
the noise environment in the immediate area of construction. Noise generated during construction
would occur with varying intensities and durations during the different phases of construction:
clear and grub, earthwork, base preparation, paving and cleanup.
The City’s construction noise criteria are that the noise levels associated with construction
activities at residential properties should not exceed 75 dBA, averaged over 8 hours during any
24-hour period.
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-7
May 2013
Project construction activities would result in a short-term, temporary increase in the ambient noise
level in the immediate area of construction. The magnitude of the impact is dependent upon the
type of construction activity and equipment generating the noise, the duration of the construction
stage, and the distance between the noise source and the receptor.
Heavy equipment is expected to include at least two large earthmovers, two graders, two large
dump trucks, two concrete trucks/mixers and two large loaders. Tractors, backhoes, skid steers,
paver/rollers, and water trucks also would be utilized. The heavy equipment has been estimated
conservatively to be in operation eight hours per day and six days per week. Construction
equipment would be expected to generate noise levels ranging from 70 to 90 dBA at a distance of
50 feet. Noise generated by construction equipment would be reduced over distance at a rate of
approximately 6 dBA per doubling of distance away from the source (Harris 1998).
With implementation of standard noise abatement features, such as mufflers, the grading and paving
construction activities are anticipated to generate noise levels that comply with the City’s noise
criteria.
There is a relatively small potential that blasting could be required in areas of shallow bedrock,
and some large rocks are present in the vicinity of Northcrest Lane on the east side of Espola
Road. (It is possible that the rocks may be broken rather than blasted apart.) If blasting is
necessary, these operations would precede other roadway grading activities and would be
completed in a relatively short time period. Any rock produced during blasting activities would
be hauled off site or buried on site fills. No crushing would occur on site.
Construction blasting can generate maximum noise levels of approximately 94 dBA at a distance
of 50 feet (Bolt Beranek and Newman 1989). The specific blasting hole sites are not known.
Because of the infrequent nature of blasting (i.e., approximately one or two blasts per day),
however, this noise level would be less than significant at residences located more than
approximately 50 feet from the blast area with proper pre-blast notices to the residents.
Blasting from construction projects generates a velocity level of approximately 100 dBA or a
peak particle velocity of approximately 0.80 inch per second (Federal Transit Administration
2006). At a distance of 65 feet from the blast, the peak particle velocity would be approximately
0.20 inch per second. This vibration level is the limit that is typically considered acceptable for
all building structures along the Project site. Thus, if blasts are proposed to be conducted within
65 feet of residences, the blasting contractor may be required to implement additional blasting
control measures.
With required adherence to the PMC regulations governing the acceptable hours of construction,
no significant impact is identified.
Operational Impacts
Typically, the peak hour Leq noise level along surface streets is approximately equal to the CNEL
value where the peak hour is between 8 and 12 percent of the ADT. This assumption was
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-8
May 2013
confirmed during a 24-hour noise measurement for the Project. Future traffic noise levels have
been projected under existing and design year conditions (with and without the proposed Project).
Table 2.3.3, Predicted Future Noise and Barrier Effectiveness Analysis, illustrates the difference
between existing conditions and the future conditions without Project improvements to set baseline
data. The table also identifies what the decibel change would be with proposed improvements to
the three-lane width for each of the receptor locations mapped on Figures 2.3-1 and 2.3-2, Noise
Receivers and Proposed Noise Barrier Locations. Following that, Table 2.3-3 identifies whether
the sensitive receptors contain a protected use area, and if so, the height of wall recommended to
provide appropriate attenuation of roadway noise under City criteria.
Where residences have existing sound walls (Barriers B1-S and B1-N) along Espola Road,
computer modeling for the future Project-related noise impacts take them into account to
determine whether the existing walls would provide sufficient noise control. Due to the roadway
traffic volumes and speeds, the traffic noise impacts do not extend to any residents beyond the
single-family residences directly along Espola Road.
The future loudest hour Leq would generally range from approximately 55 to 69 dBA at the
usable outdoor space (generally backyards) of residences without existing sound walls located
adjacent to Espola Road. The future noise level would exceed City thresholds at a number of
identified receivers with protected outdoor use areas (i.e., Sites 8-14, 18-20, 24-27, 35, 38-39, 42
and 44 on Figure 2.3-1) along Espola Road. Potentially significant impacts are identified to each
of these receptors, and sound barriers are proposed as shown on Table 2.3-3.
Some homes have front yards bordering Espola Road, but also have usable outdoor space
(generally backyards) shielded from Espola Road traffic noise by the intervening home,
topography, or other structures. These include Sites 15-17, 21-23, 41 and 45-52. No significant
impacts are identified to the front yards in these cases because usable outdoor space is provided
in the backyards. Two homes (Sites 37 and 43) are located on large lots. These homes have
apparent use areas in the front or side yards. Substantial lot area exists around these homes that
would allow for exterior use areas shielded by the homes. No significant impacts are identified.
The Montessori Child Development Center (Site M6) would be subject to a future loudest hour
Leq of approximately 64 dBA. This noise level would comply with the City noise significance
threshold. Section 216 of the Streets and Highways Code also requires abatement for noise that
intrudes into specified areas of elementary or secondary schools when the levels within these
areas exceed a one-hour average sound level of 52 dBA. The classrooms at the school adjacent
to Espola Road have air conditioning; this condition allows the classrooms to shut their
windows, operate the air conditioners, and reduce roadway noise in the classrooms. Assuming a
minimum noise reduction of 20 dBA with closed windows, the interior future loudest hour Leq
would be approximately 44 dBA at the closest classrooms. This noise level would comply with
the noise significance threshold and no operational noise impacts from the proposed Project
would occur.
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Twin Peaks Road
Mtn Road
Northcrest Lane
Titan Way
Del Poniente Road
Huntington Gate Drive
Tierra Bonita Road
Eden Grove
Via Molinero
Golden Sunset Lane
Derringer Road
Carlson Street
Kalapana Street
Jerome Drive
Roberto Rio Road
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Crestview Court
Durhullen Drive
Rio Court
Mesquite Tree
Evergreen Lane
El Topo Drive
Los Nietos Avenue
Segundo Court
Carnitas StreetEl Dolora Way
H i g h V a l l e y R o a d
Saddlebrook Court
Alando Place
Espola Road
Willow Ranch Road
B2
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B8
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B11
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B10B7
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B5-N
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B13
Job No: BAH-01 Date: 01/24/12
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Figure 2.3-2
ESPOLA ROAD IMPROVEMENT PROJECT
Noise Receivers and Proposed Noise Barrier Locations
LEGEND
!1 Noise Receiver Location
Proposed Noise BarrierB1
Section 2.3 – Noise
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1
3
0
3
0
8
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5
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t
6
7
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9
6
8
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4
6
5
6
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6
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7
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1
-
S
6
6
.
4
6
5
.
0
11
3
2
1
2
9
3
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4
1
5
3
L
o
s
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t
o
s
A
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e
6
7
.
8
6
8
.
2
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.
4
65
6
8
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4
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.
6
B
1
-
N
6
8
.
4
6
8
.
4
6
7
.
0
6
6
.
7
6
5
.
9
6
5
.
4
6
4
.
4
12
3
2
1
2
9
1
3
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7
3
5
A
l
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d
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e
6
7
.
3
6
7
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7
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4
65
6
8
.
0
0
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7
B
2
6
6
.
7
6
6
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3
6
5
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8
6
4
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13
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1
3
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5
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l
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e
6
8
.
1
6
8
.
6
0
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5
6
5
68
.
7
0
.
6
B
2
6
8
.
7
6
8
.
3
6
7
.
1
6
6
.
6
6
6
.
3
6
4
.
9
14
3
2
1
0
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0
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1
0
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4
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0
2
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s
p
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l
a
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d
6
8
.
8
6
9
.
3
0
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5
6
5
6
9
.
4
0
.
6
B
3
6
6
.
1
6
5
.
8
6
5
.
2
6
4
.
0
15
3
2
1
0
2
0
5
5
0
0
1
4
8
3
6
E
s
p
o
l
a
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a
d
6
6
.
1
6
6
.
6
0
.
5
6
5
6
7
.
0
0
.
9
–
Shielded PUA
16
3
2
1
0
2
0
6
4
0
0
1
4
8
5
6
E
s
p
o
l
a
R
o
a
d
6
6
.
6
6
7
.
0
0
.
4
6
5
6
7
.
4
0
.
8
–
Shielded PUA
17
3
2
1
0
2
0
4
0
0
0
1
4
9
0
6
E
s
p
o
l
a
R
o
a
d
6
7
.
9
6
8
.
3
0
.
4
6
5
6
8
.
5
0
.
6
–
Shielded PUA
18
3
2
1
3
3
0
0
7
0
0
1
4
1
4
5
D
u
r
h
u
l
l
e
n
D
r
i
v
e
6
7
.
8
6
8
.
2
0
.
4
6
5
6
8
.
4
0
.
6
B
4
6
2
.
9
43
3
2
1
2
1
0
3
3
0
0
1
4
9
3
7
E
s
p
o
l
a
R
o
a
d
6
3
.
6
6
4
.
0
0
.
4
6
0
6
4
.
2
0
.
6
–
Protected Outdoor Use Area Available
44
3
2
1
2
1
0
3
1
0
0
1
4
8
4
5
E
s
p
o
l
a
R
o
a
d
6
5
.
3
6
5
.
7
0
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4
6
5
6
6
.
0
0
.
7
B
1
4
6
4
.
9
45
3
2
1
2
1
0
4
5
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0
1
4
8
3
9
E
s
p
o
l
a
R
o
a
d
6
3
.
9
6
4
.
3
0
.
4
6
0
6
4
.
4
0
.
5
–
Shielded PUA
46
3
2
1
2
1
0
3
6
0
0
1
4
8
3
1
E
s
p
o
l
a
R
o
a
d
6
2
.
4
6
2
.
8
0
.
4
6
0
6
2
.
7
0
.
3
–
Shielded PUA
47
3
2
1
2
1
0
5
0
0
0
1
4
8
1
5
E
s
p
o
l
a
R
o
a
d
6
8
.
1
6
8
.
6
0
.
5
6
5
6
8
.
4
0
.
3
-
S
h
i
e
l
d
e
d
P
U
A
48
3
2
1
2
4
1
0
1
0
0
1
4
7
2
9
E
s
p
o
l
a
R
o
a
d
6
3
.
3
6
3
.
7
0
.
4
6
0
6
3
.
7
0
.
4
–
Shielded PUA
49
3
2
1
2
4
1
0
2
0
0
1
4
7
1
1
E
s
p
o
l
a
R
o
a
d
6
3
.
4
6
3
.
8
0
.
4
6
0
6
3
.
8
0
.
4
–
Shielded PUA
50
3
2
1
2
4
1
0
4
0
0
1
4
6
7
9
E
s
p
o
l
a
R
o
a
d
6
3
.
9
6
4
.
3
0
.
4
6
0
6
4
.
5
0
.
6
–
Shielded PUA
51
3
2
1
2
4
1
0
6
0
0
1
4
6
4
3
E
s
p
o
l
a
R
o
a
d
6
3
.
5
6
3
.
9
0
.
4
6
0
6
4
.
2
0
.
7
–
Shielded PUA
52
3
2
1
2
4
1
0
8
0
0
1
4
6
1
1
E
s
p
o
l
a
R
o
a
d
6
3
.
5
6
4
.
0
0
.
5
6
0
6
4
.
2
0
.
7
–
ShieldedPUA
3
1
9
3
2
1
3
3
0
0
6
0
0
1
4
1
4
4
D
u
r
h
u
l
l
e
n
D
r
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v
e
6
6
.
7
6
7
.
1
0
.
4
6
5
6
6
.
8
0
.
1
B
5
-
S
5
9
.
7
20
3
2
1
0
1
1
1
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5
0
0
4
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s
p
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l
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o
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d
6
7
.
0
6
7
.
4
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4
6
5
6
7
.
2
0
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2
B
5
-
N
6
4
.
1
21
3
2
1
0
1
1
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8
0
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5
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6
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s
p
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d
6
8
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1
6
8
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5
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4
6
5
6
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1
0
.
0
-
S
h
i
e
l
d
e
d
P
U
A
22
3
2
1
0
1
1
0
6
0
0
1
5
0
4
0
E
s
p
o
l
a
R
o
a
d
6
6
.
4
6
6
.
8
0
.
4
6
5
6
6
.
7
0
.
3
–
Shielded PUA
23
3
2
1
0
1
1
4
1
0
0
1
5
0
6
0
E
s
p
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l
a
R
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a
d
6
5
.
7
6
6
.
2
0
.
5
6
5
6
6
.
4
0
.
7
–
Shielded PUA
23
A
3
2
1
0
1
1
4
2
0
0
1
5
1
6
1
H
u
n
t
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n
g
t
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n
C
o
u
r
t
5
7
.
9
5
8
.
3
0
.
4
6
0
5
8
.
4
0
.
5
–
Shielded PUA
37
3
2
1
0
1
1
1
4
0
0
1
5
1
3
1
E
s
p
o
l
a
R
o
a
d
6
5
.
3
6
5
.
7
0
.
4
6
5
6
5
.
9
0
.
6
–
Protected Outdoor Use Area Available
38
3
2
1
0
1
1
1
3
0
0
1
5
1
2
1
E
s
p
o
l
a
R
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a
d
6
7
.
3
6
7
.
8
0
.
5
6
5
6
7
.
6
0
.
3
B
1
1
6
1
.
9
39
3
2
1
0
1
1
2
4
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5
1
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9
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s
p
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l
a
R
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d
6
7
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0
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4
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4
6
5
6
7
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5
0
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5
B
1
2
6
4
.
3
40
3
2
1
0
4
0
1
9
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2
0
8
J
e
r
o
m
e
D
r
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v
e
6
4
.
7
6
5
.
1
0
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4
6
5
6
5
.
6
0
.
9
–
Shielded PUA
41
3
2
1
0
4
0
1
8
0
0
1
4
2
1
1
J
e
r
o
m
e
D
r
i
v
e
6
6
.
2
6
6
.
6
0
.
4
6
5
6
7
.
1
0
.
9
–
Shielded PUA
42
3
2
1
2
1
0
4
0
0
0
1
4
9
4
9
E
s
p
o
l
a
R
o
a
d
6
6
.
9
6
7
.
3
0
.
4
6
5
6
7
.
8
0
.
9
B
1
3
5
7
.
5
Section 2.3 – Noise
Es
p
o
l
a
R
o
a
d
I
m
p
r
o
v
e
m
e
n
t
P
r
o
j
e
c
t
F
i
n
a
l
E
I
R
2.3-10
Ma
y
2
0
1
3
Ta
b
l
e
2
.
3
-
3
(
c
o
n
t
.
)
PR
E
D
I
C
T
E
D
F
U
T
U
R
E
N
O
IS
E
A
N
D
B
A
R
R
I
E
R
E
F
F
E
C
T
I
V
E
N
E
S
S
A
N
A
L
Y
S
I
S
Segment
Receiver
AP
N
A
d
d
r
e
s
s
Me
a
s
u
r
e
d
Co
n
d
i
t
i
o
n
s
No
P
r
o
j
e
c
t
Fu
t
u
r
e
Ci
t
y
o
f
Po
w
a
y
Cr
i
t
e
r
i
a
No
B
a
r
r
i
e
r
s
3-Lane Future
Pl
a
n
n
e
d
Ba
r
r
i
e
r
s
1
6'
Ba
r
r
i
e
r
6
1
/
2
'
Ba
r
r
i
e
r
7'
B
a
r
r
i
e
r
7 1/2' Barrier 8' Barrier 8 1/2' Barrier 9' Barrier Notes
dB
A
d
B
A
C
h
a
n
g
e
d
B
A
C
h
a
n
g
e
I
D
d
B
A
d
B
A
d
B
A
d
B
A dBA dBA dBA
4
24
3
2
1
0
1
2
4
8
0
0
1
5
2
4
4
E
s
p
o
l
a
R
o
a
d
6
4
.
3
6
4
.
8
0
.
5
6
0
6
5
.
0
0
.
7
B
6
6
2
.
3
6
1
.
6
6
1
.
0
6
0
.
5
5
9
.
8
25
3
2
1
0
1
2
4
9
0
0
1
5
3
1
8
E
s
p
o
l
a
R
o
a
d
6
2
.
8
6
3
.
3
0
.
5
6
0
6
3
.
5
0
.
7
B
7
6
0
.
7
6
0
.
4
6
0
.
1
5
9
.
6
5
8
.
8
26
3
2
1
0
1
2
5
0
0
0
1
5
3
6
0
E
s
p
o
l
a
R
o
a
d
6
1
.
2
6
1
.
6
0
.
4
6
0
6
1
.
5
0
.
3
B
8
5
8
.
9
27
2
7
8
4
5
0
2
4
0
0
1
5
4
0
8
E
s
p
o
l
a
R
o
a
d
6
3
.
5
6
3
.
9
0
.
4
6
0
6
3
.
8
0
.
3
B
9
5
8
.
9
28
2
7
8
4
5
0
1
0
0
0
1
4
1
3
5
W
i
l
l
o
w
R
a
n
c
h
R
o
a
d
5
8
.
8
5
9
.
2
0
.
4
6
0
5
4
.
9
-
3
.
9
–
I
n
C
o
m
p
l
i
a
n
c
e
29
2
7
8
4
5
0
1
1
0
0
1
5
4
5
7
M
e
s
q
u
i
t
e
T
r
e
e
T
r
a
i
l
5
9
.
8
6
0
.
2
0
.
4
6
0
6
0
.
4
0
.
6
–
I
n
C
o
m
p
l
i
a
n
c
e
30
2
7
8
4
5
0
1
3
0
0
1
5
4
7
7
M
e
s
q
u
i
t
e
T
r
e
e
T
r
a
i
l
5
9
.
7
6
0
.
2
0
.
5
6
0
6
0
.
3
0
.
6
–
I
n
C
o
m
p
l
i
a
n
c
e
31
2
7
8
4
5
0
1
5
0
0
1
5
4
9
7
M
e
s
q
u
i
t
e
T
r
e
e
T
r
a
i
l
5
9
.
4
5
9
.
8
0
.
4
6
0
5
9
.
7
0
.
3
–
I
n
C
o
m
p
l
i
a
n
c
e
32
2
7
8
4
6
2
3
9
0
0
1
5
4
9
0
H
a
r
r
o
w
L
a
n
e
5
7
.
7
5
8
.
2
0
.
5
6
0
5
8
.
2
0
.
5
–
I
n
C
o
m
p
l
i
a
n
c
e
33
2
7
8
4
6
2
3
7
0
0
1
5
4
7
8
H
a
r
r
o
w
L
a
n
e
5
8
.
2
5
8
.
6
0
.
4
6
0
5
8
.
6
0
.
4
–
I
n
C
o
m
p
l
i
a
n
c
e
34
2
7
8
4
6
2
3
5
0
0
1
5
4
6
4
H
a
r
r
o
w
L
a
n
e
5
8
.
2
5
8
.
6
0
.
4
6
0
5
9
.
0
0
.
8
–
I
n
C
o
m
p
l
i
a
n
c
e
35
3
2
1
0
1
2
5
2
0
0
1
5
3
6
1
E
s
p
o
l
a
R
o
a
d
6
3
.
8
6
4
.
2
0
.
4
6
0
6
4
.
6
0
.
8
B
1
0
6
2
.
8
6
2
.
2
6
1
.
5
6
0
.
7
5
9
.
9
36
3
2
1
0
1
1
1
5
0
0
1
5
1
5
9
E
s
p
o
l
a
R
o
a
d
5
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Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-11
May 2013
A church and commercial area are located south of Twin Peaks Road (Sites M1 and 53). Only
construction activities primarily associated with an existing storm drain system are proposed south of
Twin Peaks Road. There are no road widening improvements proposed for this area with associated
Project changes in traffic proximity, and this area is not further addressed. No significant impacts
would occur.
The reader should note that because the Project is anticipated to receive partial federal funding, if
the Project is approved by the City for construction, technical report requirements in accordance
with NEPA also would be required in order for federal monies to be released. Noise modeling in
accordance with standards current to FHWA and Caltrans would be completed at that time as part
of a separate effort (see further discussion in Section 2.3.4, below).
2.3.4 Mitigation Measures
Construction Period
No mitigation is required for the less-than-significant short-term construction-period impacts.
The City is recommending the following construction noise control measures, however, to
further minimize noise effects at noise-sensitive locations during Project construction:
Each internal combustion engine, used for any purpose on the job or related to the job,
shall be equipped with a muffler of a type recommended by the manufacturer. No
internal combustion engine shall be operated on the Project without said muffler.
The noise level requirement shall apply to the equipment on the job or related to the job,
including but not limited to trucks, transit mixer, or transient equipment that may or may
not be owned by the contractor.
The use of loud signals shall be avoided in favor of light warnings except those required
by safety laws for the protection of personnel.
Unnecessary idling of internal combustion engines within 100 feet of residences should
be strictly prohibited.
Staging of construction equipment beyond 200 feet of residences and location of all
stationary noise-generating construction equipment, such as air compressors and portable
power generators, shall occur as far as practical from noise sensitive residences. The
contractor will place all stationary construction equipment so that emitted noise is
directed away from sensitive receptors (residences).
As directed by the City, the contractor will implement appropriate additional noise
mitigation measures, including changing the location of stationary construction
equipment, turning off idling equipment, rescheduling construction activity, notifying
adjacent residents in advance of construction work, and installing acoustic barriers
around stationary construction noise sources.
Following Project Completion
In accordance with the City General Plan Public Safety Element, noise reduction strategies were
considered where Project impacts would expose existing residences to higher noise levels
exceeding General Plan standards. City guidelines specify that noise abatement must be provided
Section 2.3 – Noise
Espola Road Improvement Project Final EIR 2.3-12
May 2013
to impacted residents where feasible. Factors that affect feasibility include topography, access
requirements for driveways and ramps, presence of local cross streets, utility conflicts, other noise
sources in the area, and safety considerations. The overall reasonableness of noise abatement is
determined by considering factors such as predicted future increase in noise levels, expected noise
abatement benefits, environmental impacts of abatement construction, opinions of affected
residents, etc.
Because of the configuration and location of the Project, abatement in the form of noise barriers is
the only noise reduction strategy that is considered feasible, since Espola Road is already regulated
to low speeds (45 miles per hour), and is immediately abutted by residential (and other) uses which
would preclude the use of a buffer zone between the roadway and noise-sensitive receivers. Each
of the walls proposed as mitigation meet initial feasibility and reasonableness criteria.
As noted above, the City does not typically mitigate traffic noise at front yard areas as the focus is
the outdoor space primarily used for recreational purposes by the resident (generally the backyard).
The homes with front yards facing Espola Road also often have driveway entrances along Espola
Road, which would limit the effectiveness of noise barriers placed along this segment of Espola
Road. In addition, even if City standards would ordinarily mandate a higher wall to achieve
recommended attenuation levels specified in the City Noise Element, City noise protection walls
may be limited to a height of eight feet, if a taller wall is deemed to be aesthetically adverse.
Preliminary information on the potential physical location and height of recommended noise
barriers is provided in Table 2.3-3. Sound barriers of various heights are proposed based on
which of the criteria the receiver falls within (currently under 60 dBA, between 60 and 65 dBA,
or over 65 dBA), as described in Section 2.3.1. In general, sound walls of six to eight feet in
height are proposed to address the current and increased noise along Espola Road. A few walls
may exceed those heights, as indicated on Table 2.3-3. Figure 2.3-2 schematically indicates the
proposed wall locations.
Final design and placement of noise walls would require additional engineering input, including
consideration of site-specific conditions and further noise modeling. Future modeling required as
part of the NEPA compliance and funding effort for the Project, as well as input from property
owners (who may not desire walls) also could result in changes to wall parameters.2 If pertinent
engineering parameters change substantially during the final Project design, or if property owners
reject proposed walls located on their private property, preliminary noise barrier designs may be
modified (in height or extent) or eliminated from the final Project.
If and when federal and final modeling is required and completed, a consistency analysis would be
completed to confirm that sound barrier requirements do not vary substantially from those
discussed above. If walls do vary substantially (e.g., changes in location, length or height),
subsequent analysis may be required under CEQA.
2 Federal funding would not be provided for any sound wall where future noise levels would drop below 66 dBA.
Differences between City and federal thresholds may result in varying wall height. Based on current federal
modeling standards, it is considered likely that the proposed height of a number of walls could vary by one-half
foot to two feet. Greater or lesser attenuation could be proposed due to federal requirements for attainment of
minimum reduction levels prior to funding.