HomeMy WebLinkAbout3.10_Noise_FroomRanch_DEIR3.10 NOISE
3.10 NOISE
This section describes the existing noise environment and evaluates the potential noise and
vibration impacts that could result from short-term construction and long-term operation
of the Project.
3.10.1 Environmental Setting
3.10.1.1 Fundamentals of Sound and Environmental Noise
Noise
Sound is technically described in terms of the loudness (amplitude) and frequency (pitch)
of the sound. Noise is typically defined as unwanted sound that interferes with normal
activities or otherwise diminishes the quality of the environment. Prolonged exposure to
high levels of noise is known to have several adverse effects on people, including hearing
loss, communication interference, sleep interference, physiological responses, and
annoyance. The noise environment typically includes background noise generated from
both near and distant noise sources as well as the sound from individual local sources.
These can vary from an occasional aircraft or train passing by to continuous noise from
sources such as traffic on a major road.
The standard unit of measurement of the loudness of sound is the decibel (dB). Since the
human ear is not equally sensitive to sound at all frequencies, a special frequency-dependent
rating scale has been devised to relate noise to human sensitivity. The A-weighted decibel
scale (dBA) performs this compensation by discriminating against frequencies in a manner
approximating the sensitivity of the human ear. In terms of human response to noise, studies
have indicated that a noise level increase of 3 dBA is barely perceptible to most people, a 5-
dBA increase is readily noticeable, and a difference of 10 dBA would be perceived as a
doubling of loudness. Everyday sounds normally range from 30 to 100 dBA. Examples of
various noise levels in different environments are shown in Table 3.10-1.
Several rating scales have been developed to analyze the adverse effect of community noise
(a.k.a. environmental noise) on people. Since community noise fluctuates over time, these
scales consider the total acoustical energy content of the noise, as well as the time of day
when the noise occurs. Each noise metric applicable to this analysis is defined as follows:
• Leq (equivalent energy noise level) is the average acoustic energy content of noise
for a stated period of time. Thus, the Leq of a time-varying noise and that of a steady
noise are the same if they deliver the same acoustic energy to the ear during
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3.10 NOISE
exposure. For evaluating community impacts, this rating scale does not vary,
regardless of whether the noise occurs during the day or the night. Leq is one of the
most frequently used noise metrics as it considers both duration and sound pressure
level. Typically Leq is summed over a 1-hour period.
• CNEL (Community Noise Equivalent Level) is a 24-hour average Leq with a 5 dBA
“weighting” during the hours of 7:00 PM to 10:00 PM and a 10 dBA “weighting”
added to noise during the hours of 10:00 PM to 7:00 AM to account for noise
sensitivity in the evening and nighttime, respectively. The logarithmic effect of
these additions is that a 60 dBA 24-hour Leq would result in a measurement of 66.7
CNEL. CNEL is often used due to its utility in identifying noise-related sleep
disturbance effects, often a key community concern for increases in noise levels.
Most California noise laws specify levels using the CNEL metric and most federal
laws use the Leq metric. The City noise thresholds utilize the CNEL and Ldn metric.
• Ldn (day-night average noise level) is a 24-hour average Leq with a 10 dBA
“weighting” added to noise during the hours of 10:00 PM to 7:00 AM to account
for noise sensitivity in the nighttime. The logarithmic effect of these additions is
that a 60 dBA 24-hour Leq would result in a measurement of 66.4 Ldn. The City
noise thresholds utilize the CNEL and Ldn metric.
• Lmin (minimum instantaneous noise level) is the minimum instantaneous noise level
experienced during a given period of time.
• Lmax (maximum instantaneous noise level) is the maximum instantaneous noise
level experienced during a given period of time.
• Noise levels from a particular source decline (attenuate) as distance to the receptor
increases.1 Other factors, such as the weather and reflecting or shielding by
buildings or other structures, intensify or reduce the noise level at a location. A
common method for estimating roadway noise, which dissipates more quickly than
stationary sources as the noise source (vehicle) moves away from the receptor, is
that for every doubling of distance from the source, the noise level is reduced by
about 3 dBA at acoustically “hard” locations (i.e., mostly asphalt, concrete, hard-
packed soil, or other solid materials) and 4.5 dBA at acoustically “soft” locations
(i.e., contains natural earth or vegetation, such as grass).
• Noise from stationary or point sources (including construction noise) is reduced by
about 6 to 7.5 dBA for every doubling of distance at acoustically hard and soft
locations, respectively. Noise levels may also be reduced by intervening structures.
Generally, a single row of buildings between the receptor and the noise source
reduces the noise level by about 5 dBA, while a solid wall or berm can reduce noise
levels by up to 5 to 10 dBA. The manner in which older homes in California were
constructed generally provides a reduction of exterior-to-interior noise levels of
about 20 to 25 dBA with closed windows. The exterior-to-interior noise reduction
of newer residential units is generally 30 dBA or more (FHWA 2014).
1 With regard to noise, a receptor is defined as a stationary far-field position at which noise or vibration
levels are specified (U.S. Department of Transportation 2012).
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Table 3.10-1. Representative Noise Levels
Common Outdoor Activities Noise Level
(dBA) Common Indoor Activities
Power Saw —110— Rock Band
Jet Fly-over at 1000 feet Crying Baby
Subway —100—
Gas Lawnmower at 3 feet
Rail Transit Horn/ Tractor —90—
Heavy Construction Truck at 50 feet/
Street Sweeper at 50 feet Food Blender at 3 feet
Concrete Mixer Truck at 50 feet —80— Garbage Disposal at 3 feet
Noisy Urban Area during Daytime
Gas Lawnmower at 100 feet —70— Vacuum Cleaner at 10 feet
Rail Transit in Station/ Commercial
Area Normal Speech at 3 feet
Heavy Traffic at 300 feet —60— Sewing Machine
Air Conditioner Large Business Office
Quiet Urban Area during Daytime —50— Dishwasher in Next Room
Refrigerator
Quiet Urban Area during Nighttime —40— Theater, Large Conference Room
(background)
Quiet Suburban Area during
Nighttime
—30— Library
Quiet Rural Area during Nighttime Bedroom at Night, Concert Hall
(background)
—20—
Broadcast/Recording Studio
—10—
Lowest Threshold of Human Hearing —0— Lowest Threshold of Human Hearing
Source: Caltrans 1998.
Groundborne Vibration
In the context of noise, groundborne vibration is the vibration, or oscillation, of the ground,
floor, and walls. The vibration of floors and walls may cause perceptible vibration, rattling
of items such as windows or dishes on shelves, or a rumble noise. The rumble is the noise
radiated from the motion of the room surfaces. In essence, the room surfaces act like a giant
loudspeaker causing what is called groundborne noise. Groundborne vibration is almost
never annoying to people who are outdoors. Although the motion of the ground may be
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3.10 NOISE
perceived, without the effects associated with the shaking of a building, the motion does
not provoke the same adverse human reaction. In addition, the rumble noise that usually
accompanies the building vibration is perceptible only inside buildings. The ground motion
caused by vibration is measured as particle velocity in inches per second; in the U.S., this
is referenced as vibration decibels (VdB) (Harris Miller & Hanson Inc. 2006).
The vibration velocity level threshold of perception for humans is approximately 65 VdB.
A vibration velocity level of 75 VdB is the approximate dividing line between barely
perceptible and distinctly perceptible levels for many people. Most perceptible indoor
vibration is caused by sources within buildings, such as operation of mechanical
equipment, movement of people, or the slamming of doors. Typical outdoor sources of
perceptible groundborne vibration include construction equipment (e.g., heavy haul trucks,
concrete trucks) and traffic on rough roads. If a roadway is smooth, the groundborne
vibration from automobile traffic is rarely perceptible, although larger trucks carrying
heavy loads can generate perceptible vibration. The range of interest (velocity level) for
groundborne vibration is from approximately 50 VdB to 100VdB. General human response
to different levels of groundborne vibration velocity levels are described in Table 3.10-2.
A velocity level of 50 VdB is the typical background vibration velocity level, while a
velocity level of 100 VdB is the general threshold where minor damage can occur in fragile
buildings (Harris Miller Miller & Hanson Inc. 2006).
Table 3.10-2. Human Response to Different Levels of Groundborne Vibration
Vibration Velocity Level Human Response
65 VdB Approximate threshold of perception for many humans.
75 VdB Approximate dividing line between barely perceptible and distinctly
perceptible. Many people find transit vibration at this level annoying.
85 VdB Vibration acceptable only if there are an infrequent number of events per
day.
Source: Harris Miller Miller & Hanson Inc. 2006.
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3.10 NOISE
3.10.1.2 Existing Noise Environment
The Project site is bordered by the Irish
Hills Natural Reserve to the west, retail
and commercial businesses within the
Irish Hills Plaza to the north, LOVR and
automobile dealerships to the northeast,
hotels along Calle Joaquin to the
southeast, and Mountainbrook Church to
the south. There are three primary
sources of noise within the area:
roadways such as U.S. 101 which lies 700 to 1,000 feet to the east, and LOVR, which
immediately borders the site to the northeast; the Airport located 2 miles to the east; and
operation of nearby commercial businesses.
Existing noise levels within the Project vicinity fall within typical suburban levels. Higher
noise levels are found proximate to roadway corridors and also near commercial centers
where loud speakers from automobile centers and truck loading bay at shopping centers
create local higher peak noise levels. Quieter areas include those near residential
neighborhoods and the rural Irish Hills, located farther from noise generation sources. The
City’s General Plan Noise Element (NE) generally identifies noise levels at the Project as
being below 60 dB. Overall, airport noise is similarly low given the limited number of
overflights and distance from runways and is considered to be less than 50 dB under the
Airport’s current ALUP (ALUC 2005).
A range of source material was reviewed and utilized in determining the existing noise
setting. The City’s General Plan NE was adopted in 1996 and thus existing noise levels
from that 23-year old document are out of date. Similarly, the ALUP noise contours were
last updated in 2005, are more than 14 years old, and are currently being updated. The two
most recent sources for noise levels on the Project site and vicinity include the 2014 LUCE
Update EIR and the Applicant-prepared Acoustics Assessment, completed in 2017. These
two documents therefore form the primary basis for describing the existing noise setting.
The LUCE Update EIR was a citywide document that utilized general programmatic
information and analysis that may not precisely reflect the physical conditions of the
Project site or vicinity. The Acoustics Assessment utilized six onsite noise measurements
taken on a Saturday morning between 10:00 AM and 12:00 PM. These measurements are
used as a basis for onsite noise modeling analyzed in the Acoustics Assessment. The
Noise generated from vehicular traffic along area
roadways, such as LOVR are substantial contributors to
existing noise levels on the Project site.
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findings of the LUCE Update EIR and the Acoustics Assessment for existing onsite noise
levels are discussed below (see also below Section 3.10.3.2, Impact Assessment
Methodology).
Roadway Noise
U.S. 101 generates the highest noise levels in the Project vicinity. Located approximately
700 to 1,100 feet east of the Project site, this segment of U.S. 101 carries traffic volumes
between 65,300 and 80,000 average daily trips (ADT) (Caltrans 2017). LOVR also
generates substantial roadway noise in the Project vicinity. LOVR extends immediately
adjacent along the northern Project site boundary for approximately 1,700 feet, and carries
approximately 30,000 ADT (City of San Luis Obispo 2014). Portions of LOVR that are
farther away from the site, as well as Calle Joaquin and other nearby collector roads, carry
relatively low traffic volumes, do not generate substantial noise levels on the Project site,
and, therefore, are not discussed further in this section.
The City’s LUCE Update EIR provides general noise modeling of roadway traffic noise
measured from the centerline of U.S. 101 and LOVR based on roadway traffic volumes,
but does not consider natural or manmade features, such as topography, vegetation, walls,
or buildings, that may block and reduce noise volumes (City of San Luis Obispo 2014,
Table 4.11-1). The LUCE Update EIR indicates that the 60 dBA to 65 dBA noise corridors
(the maximum acceptable exterior noise level generated by transportation noise sources for
sensitive land uses based on City adopted noise guidelines) from the centerlines of U.S 101
and LOVR extend well onto the Project site (Table 3.10-3; Figure 3.10-1).
Table 3.10-3. LUCE Update EIR Projected Roadway Noise Levels within Project Site
Roadway Noise Source
Description U.S. 101 LOVR
Distance to Project site1 (ft) 700 - 1,100 40
Distance of 65 dBA CNEL noise contour
from roadway centerline2 (ft)
1,260 - 1,560 75
Distance of 60 dBA CNEL noise contour
from roadway centerline (ft)
7,140 239
1As measured from roadway centerline.
2As projected in the LUCE Update EIR.
3Source: City of San Luis Obispo 2014. Roadway traffic noise modeling conducted by Ascent Environmental, Inc.
Although U.S. 101 lies between 700 and 1,100 feet to the south and east of the Project site,
noise corridor modeling from the LUCE Update EIR indicates that the entire Project site
may be located within the 60 dBA CNEL generated by traffic along U.S. 101, with well
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3.10 NOISE
over 50 percent of the south and east ends of the Project site projected to fall within the 65
dBA CNEL contour. The 60 dBA CNEL for LOVR, which immediately borders the site to
the east, may extend west as far as 240 feet into the Project site; the 65 dBA CNEL may
extend as far as 35 feet into the Project site (see Figure 3.10-1).
However, roadway noise corridor modeling in the LUCE Update EIR does not consider
reductions in noise resulting from nearby topographic or manmade features that block or
redirect sound waves. In the case of the LOVR noise corridor, level topography and a lack
of manmade barriers appear to render the programmatic LUCE Update EIR noise corridor
modeling generally accurate. However, for U.S. 101, the outlying flank of the Irish Hills
that support Mountainbrook Church and the KSBY radio station, four hotels along Calle
Joaquin between U.S. 101 and the Project site, and the elevated LOVR overpass likely
result in substantial reductions to noise from U.S. 101 to levels well below those modeled
in the LUCE Update EIR. This conclusion is also substantiated by the results of the
Acoustic Assessment, as further discussed below.
Mountainbrook Church sits on a hill that rises over 200 feet in elevation and largely or
entirely blocks noise generated by vehicles on U.S. 101 to the south. The LOVR overpass
has a similar noise attenuating effect for vehicular noise to the north. Of the Project site’s
approximately 1,700 feet of frontage directly facing U.S. 101 between the Mountainbrook
Church hill and the LOVR overpass, the four-story Hampton Inn and Suites, three-story
Courtyard by Marriot, two-story Motel 6, and one-story Rose Garden Inn provide
additional substantial barriers to noise generated by U.S. 101. As noted in Section 3.10.1.1
Fundamentals of Sound and Environmental Noise, a single row of buildings between the
receptor and the noise source generally reduces the noise level by approximately 5 dBA,
while a solid wall or berm (e.g., LOVR overpass) can result in noise level reductions
between 5 to 10 dBA. While gaps between hotel buildings may have potential for exposure
to noise from U.S. 101, LUCE Update EIR noise modeling was general and did not
consider site-specific features or conditions; therefore, the LUCE Update EIR likely
overestimates noise levels within the Project site from U.S. 101 by 5 to 10 dBA. However,
conservatively, the southern portion of the site along Froom Creek may remain potentially
exposed to noise levels of approximately 60 dBA (Figure 3.10-1).
Froom Ranch Specific Plan 3.10-7
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55
58
54
61
50
55 ROSE GARDEN INN
MOTEL 6
HAMPTON INN
MARRIOTT6565606070
657070WHOLE
FOODSLOS OSOS VALLEY ROADLOS OSOS VALLEY ROADCALLE JOA Q UINT.J.
MAXX
AUTO
DEALERSHIPSWHOLE
FOODS
HOME
DEPOT
IRISH HILLS
NATURAL RESERVE
IRISH HILLS
NATURAL RESERVE
6565707065606070ROSE GARDEN INNMARRIOTT
MOTEL 6
HAMPTON INN
MOUNTAINBROOK
CHURCH
101
101
2
3
4
5
6
1
55
58
54
61
50
55
MOUNTAINBROOK
CHURCH HILL
# ##
LEGEND
Roadway Noise Distances
(feet from roadway centerline)
Project Site
60 CNEL (dBA) Level Roadway
Noise Contour (approximate)
65 CNEL (dBA) Level Roadway
Noise Contour (approximate)
70 CNEL (dBA) Level Roadway
Noise Contour (approximate)
Noise Sensitive Receptor
Truck Delivery and Loading Area
Loudspeaker
Approximate Noise Monitoring
Station Location and Number
with dBA Level Indicated (Station
numbers correspond to those
presented in Table 3.10-1)
Irish Hills Natural Reserve
City of San Luis Obispo
County of San Luis Obispo
U.S. 101
60 65 70
7,140 2,258 714
L.O.V.R. 239 75 24
Source: City of San Luis Obispo, LUCE
Update EIR Table 4.11-1, 2014.
6060
6565
7070
0 700
SCALE IN FEET
N
Noise Environment 3.10-1
FIGURE
3.10-8
3.10 NOISE
The Applicant-prepared Acoustics Assessment includes onsite noise measurements and
noise modeling based upon these measurements (Appendix I). Onsite noise measurements
were conducted for the Acoustics Assessment at six locations within the Project site
between 10:00 AM and 12:00 PM on Saturday, April 22, 2017. These measurement
locations recorded noise levels of 61 dBA adjacent to LOVR and 55 dBA in the south-
central area of the site, approximately 300 feet north of the Courtyard by Marriott hotel
(see Table 3.10-4; Figure 3.10-1).
Although the Acoustics Assessment briefly mentions other noise sources in the Project
vicinity (e.g., airport noise, commercial businesses), it focuses on noise generated by
traffic, particularly from LOVR and U.S. 101 as these generate the greatest level of noise
at the Project site and are the most subject to change under the Project (Appendix I).
Table 3.10-4. Measured Noise Levels within the Project Site1
Station No. Location2 Ldn /CNEL
1 Along Calle Joaquin and the southeastern boundary of the site 55 dBA
2 South central site approximately 200 feet north of Marriot Hotel 55 dBA
3 Northeastern interior of the site; 200 feet from LOVR 58 dBA
4 Northeastern interior of the site; 300 feet from LOVR 54 dBA
5 Along the boundary of Project site and LOVR 61 dBA
6 Southeastern interior of the site; 300 feet from Calle Joaquin 50 dBA
Source: Lord and Taubitz 2017.
1Roadway noise measurements conducted on Saturday, April 22, 2017, between 10:00 AM and 12:00 PM.
2See Figure 3.10-1 for precise locations.
As part of the Acoustics Assessment, an acoustic model with noise level contours was
generated for the site based on topography, noise sources, and measured noise level values
(Appendix I). The Acoustics Assessment found that the interior areas of the site generally
fall within the 50 to 60 dBA CNEL noise contour, primarily generated by vehicular traffic
on LOVR and more distant U.S. 101.
Airport Noise
The Airport is located approximately 1.8 miles east of the Project site; aircraft flying in the
vicinity at above 1,000 feet in elevation several times a day generate intermittent low-level
noise. The Project site is approximately 1,000 feet from the 50 dBA CNEL contour mapped
within the ALUP, representing the noise environment from aircraft flying in the vicinity of
the Project site (ALUC 2005). The General Plan NE indicates the Project site lies over 1
mile from the projected 60 dBA CNEL noise contour within the ALUP. Thus, Airport
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3.10 NOISE
activities only generate episodic noise on the Project site from aircrafts flying overhead,
and overall noise levels resulting from Airport operations are less than 50 dBA CNEL.
Stationary Sources
Noise is also generated from commercial uses that border the Project site, particularly Irish
Hills Plaza to the north, as well as automobile dealerships along Auto Park Way to the
northeast, and four hotels to the east. Operational noise generated by these commercial uses
includes semi-truck deliveries (85 dBA Lmax at 50 feet) and associated backup alarms,
parking lot sweeping (82 dBA Lmax at 50 feet), landscape maintenance, rooftop heating and
cooling equipment, and loudspeakers from automobile dealerships (89 dBA Lmax at 50 feet)
(FHWA 2013; see Table 3.10-1). Noise generated from such adjacent uses primarily affects
the northern area of the Project site associated with Madonna Froom Ranch. Given
proximity and types of activities, loading dock activity at the Irish Hills Plaza likely
generates the highest levels of noise adjacent to the Project site. Although these operational
activities are periodic in nature and do not typically result in high levels of continuous
noise, noise levels of 65 dB Lmax would extend as far as 95 feet into the Project site, with
noise levels increasing with proximity to the activity.
Businesses adjacent to the Project site within Irish Hills Plaza include Home Depot, TJ
Maxx, and Whole Foods. The loading docks of these businesses are located approximately
60 to 70 feet from the Project site’s northern boundary and directly face the Project. These
businesses receive regular deliveries by large semi-trucks, as well as deliveries from
smaller vendors with variable schedules and frequency. TJ Maxx typically has one semi-
truck delivery that occurs from 6:30 AM to 8:30 AM on weekdays, with occasional
deliveries on Saturdays and during holidays (TJ Maxx 2019). Home Depot typically has
10 to 15 daily weekday deliveries by semi-trucks that occur between 6:00 AM and 9:00
PM (Home Depot 2019). Whole Foods receives between 5 to 7 deliveries every day of the
week by refrigerated semi-trucks that can occur from 5:00 AM to 1:30 PM Whole Foods
2019). In total, TJ Maxx, Whole Foods, and Home Deport receive a combined average of
82 weekly deliveries via semi-trucks to loading docks adjacent to the Project site, as well
as multiple smaller deliveries (e.g., UPS, FedEx). In addition to the noise resulting from
operation of semi-trucks, deliveries generate additional noises from equipment such as
refrigeration units, forklifts, and loudspeakers. Additionally, backup alarms are required
by law to be audible above background noise levels.
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While vehicular noise identified in the Acoustics Assessment from LOVR and U.S. 101
constitute the main source of ambient noise levels onsite, periodic high noise levels
generated by adjacent commercial uses also extend into the Project site.
3.10.1.3 Sensitive Receptors
Noise sensitive uses, or sensitive receptors, generally include single- and multi-family
residences, schools, libraries, medical care facilities, retirement/assisted living homes,
guest lodging, recreational areas, and places of worship. Such uses can be sensitive to
increases in both short-term and long-term noise due to a range of issues, such as sleep
disturbance and disruption of conversations, lectures or sermons, or decreased
attractiveness of exterior use areas, such as patios, backyards, outdoor pool decks, or parks.
Of particular concern is exposure of sensitive receptors to long-term elevated interior noise
levels and sleep disturbance, which can be associated with health concerns.
No sensitive land uses are currently located within the Project site. Sensitive land uses in
the Project vicinity include Mountainbrook Church and the hotels along Calle Joaquin.
Mountainbrook Church is located approximately 75 feet from the southern boundary of the
Project site and 580 feet from the Upper Terrace. The church is open daily and offers
religious services throughout the week, including classes and programs for children and
youth, with most programs offered during evenings and weekends. Four hotels (Rose
Garden Inn, Courtyard by Marriott, Hampton Inn & Suites, and Motel 6), three of which
have outdoor pools (Rose Garden Inn, Courtyard by Marriott, and Motel 6), are located
approximately 40 to 160 feet to the east of the site boundary. These facilities lie along Calle
Joaquin with setbacks of 75 to 230 feet between the roadway and the noise-sensitive uses
(hotel rooms or pools). The closest school is Pacific Beach High School, which is
approximately 0.27 mile northwest of the Project site. The closest existing residential area
is approximately 0.3 mile northeast of the Project site.
Additionally, the Project site is located adjacent to the Irish Hills Natural Reserve, an
approximately 1,110-acre City-owned natural open space area supporting substantial
public recreational trails, as well as a wide variety of native habitats and wildlife species.
Irish Hills Natural Reserve supports over 8 miles of trails, including Neil Havlik Way and
the Froom Creek Trail, segments of which closely border the Project site. Although the
exact distance from the Project boundary varies along these trails, the shortest distance is
approximately 70 feet at the Project’s northwest boundary. These trails draw hikers, trail
runners, mountain bikers, and school groups attracted to the Reserve’s natural and
undeveloped character. This area also supports several special status wildlife species that
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3.10 NOISE
can be sensitive to noise – for discussion of possible noise impacts on wildlife (e.g.,
foraging, nesting, and reproductive activities), see Section 3.4, Biological Resources.
3.10.2 Regulatory Setting
Noise is governed primarily by federal, state, and local laws that would apply to future
development under the Project. Federal, state, and local regulations that are directly
relevant to the Project are summarized below.
3.10.2.1 Federal
Federal Transit Administration Criteria
The Federal Transit Administration (FTA) developed methodology and significance
criteria to evaluate vibration impacts from surface transportation modes (i.e., passenger
cars, trucks, buses, and rail) in the Transit Noise Impact and Vibration Assessment (Harris
Miller Miller & Hanson Inc. 2006). For residential buildings (Category 2), the threshold
applicable to these projects is 80 VdB.
Federal Noise Control Act (1972)
Public Law 92-574 regulates noise emissions from operation of all construction equipment
and facilities; establishes noise emission standards for construction equipment and other
categories of equipment; and provides standards for the testing, inspection, and monitoring
of such equipment. This Act gives states and municipalities primary responsibility for noise
control.
3.10.2.2 State
State of California’s Guidelines for the Preparation and Content of Noise Element of the
General Plan (1987)
These guidelines reference land use compatibility standards for community noise
environments as developed by the California Department of Health Services, Office of
Noise Control. Noise levels up to 60 Ldn or CNEL are determined to be normally acceptable
for single-family residential land uses. Noise levels up to 65 Ldn or CNEL are determined
to be normally acceptable for multi-family residential land and transient lodging (e.g.,
hotels) land uses. Noise levels up to 70 CNEL are normally acceptable for nursing homes,
hospitals, neighborhood parks, and business commercial land uses.
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The California Administrative Code Title 24, Noise Insulation Standards
These standards regulate interior noise levels for all new residences to 45 Ldn or below. If
exterior noise levels exceed 60 Ldn, Title 24 requires the preparation of an acoustical
analysis showing that the proposed design would limit the noise level to or below the
interior 45 Ldn requirement.
3.10.2.3 Local
City of San Luis Obispo General Plan, Noise Element and Noise Guidebook (1996)
According to state law, a Noise Element is required in all city and county general plans.
The City’s maximum noise exposure standards for noise-sensitive land use (specific to
transportation noise sources) are shown in Table 3.10-5. Since residential land uses are
considered noise-sensitive, there are recommended maximum noise exposure guidelines.
Policy 1.3. New Development Design and Transportation Noise Sources. New noise-
sensitive development shall be located and designed to meet the maximum outdoor and
indoor noise exposure levels of Table 3.10-5.
Policy 1.4. New Transportation Noise Sources. Noise created by new transportation noise
sources, including road, railroad, and airport expansion projects, shall be mitigated to not
exceed the levels specified in Table 3.10-5 for outdoor activity areas and indoor spaces of
noise-sensitive land uses which were established before the new transportation noise
source.
Policy 1.6. New Development and Stationary Noise Sources. New development of noise-
sensitive land uses may be permitted only where location or design allow the development
to meet the standards of Table 3.10-5 for existing stationary noise sources.
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Table 3.10-5. City Maximum Noise Exposure for Noise-Sensitive Land Use Areas
Due to Transportation Noise Sources
Land Use
Outdoor
Activity Areas1 Interior Spaces
Ldn2 or CNEL Ldn2 or CNEL Leq3 Lmax
Residences, hotels, motels, hospitals, nursing
homes
60 45 -- 60
Theaters, auditoriums, music halls -- -- 35 60
Churches, meeting halls, office building,
mortuaries
60 -- 45 --
Schools, libraries, museums -- -- 45 60
Neighborhood parks 65 -- -- --
Playgrounds 70 -- -- --
1 If the location of outdoor activity areas is not shown in the column, the outdoor noise standard shall apply at the
property line of the receiving land use.
2 Ldn (day-night average noise level) is the is the energy-averaged noise level measured over a 24-hour period, with a
10-dB penalty assigned to noise events occurring between 10:00 PM and 7:00 AM and a 5-dB penalty assigned to noise
events occurring between 7:00 PM and 10:00 PM.
3 Leq (equivalent noise level) is the constant or single noise level containing the same total energy as a time-varying
sound, over a certain time. If the location of outdoor activity areas is not shown, the outdoor noise standard shall apply
at the property line of the receiving land use.
Source: City of San Luis Obispo 1996.
Policy 1.7. New or Modified Stationary Noise Sources. Noise generated by new stationary
sources, or by existing stationary noise sources which undergo modifications that may
increase noise levels, shall be mitigated so as not to exceed the exposure standards for lands
designated for noise-sensitive uses, as measured at the property line of the receiver.
The City’s General Plan NE lists mitigation strategies in a descending order of desirability.
If preferred strategies are not implemented, it is the responsibility of the Applicant to
demonstrate through a detailed noise study that the more desirable approaches are either
not effective or not practical, before considering other design criteria contained in the
General Plan.
Policy 1.8. Preferred Noise Mitigation Approaches. When approving of new development
of noise-sensitive uses or noise sources, the City will require noise mitigation in the
descending order of desirability shown below.
1.8.1. Mitigating Noise Sources
A. Arrange activity areas on the site of the noise-producing project so
project features, such as buildings containing uses that are not noise-
sensitive, shield neighboring noise-sensitive uses;
B. Limit the operating times of noise-producing activities;
3.10-14 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
C. Provide features, such as walls, with a primary purpose of blocking
noise.
1.8.2. Mitigating Outdoor Noise Exposure
A. Provide distance between noise source and recipient;
B. Provide distance plus planted earthen berms;
C. Provide distance and planted earthen berms, combined with sound walls;
D. Provide earthen berms combined with sound walls;
E. Provide sound walls only;
F. Integrate buildings and sound walls to create a continuous noise barrier.
1.8.3. Mitigating Indoor Noise Exposure
A. Achieve indoor noise level standards assuming windows are open;
B. Achieve indoor noise level standards assuming windows must be closed
(this option requires air conditioning or mechanical ventilation in
buildings).
Policy 1.10. Existing and Cumulative Impacts. The City would consider the following
mitigation measures appropriate where existing noise levels significantly impact noise-
sensitive land uses, or where cumulative increases in noise levels resulting from new
development significantly impact existing noise-sensitive land uses:
A. Rerouting traffic onto streets that can maintain desired levels of service,
consistent with the Circulation Element, and which do not adjoin noise-
sensitive land uses;
B. Rerouting trucks onto streets that do not adjoin noise-sensitive land uses;
C. Constructing noise barriers;
D. Reducing traffic speeds through street or intersection design methods;
E. Retrofitting buildings with noise-reducing features;
F. Establishing financial programs, such as low-cost loans to owners of a noise-
impacted property, or developer fees to fund noise-mitigation or trip-reduction
programs.
New development of noise-sensitive land uses may only be permitted where standards are
met via location or design, as outlined in Table 3.10-6.
Froom Ranch Specific Plan 3.10-15
Draft EIR
3.10 NOISE
Table 3.10-6. City Maximum Noise Exposure for Noise-Sensitive Land Use Areas
Due to Stationary Noise Sources
Daytime
(7:00 AM to 10:00 PM)
Nighttime2
(10:00 PM to 7:00 AM)
Hourly Leq in dB1, 2 50 45
Maximum level in dB1, 2 70 65
Maximum impulsive noise in dB1, 3 65 60
1 As determined at the property line of the receiver. When determining effectiveness of noise mitigation measures, the
standards may be applied on the receptor side of noise barriers or other property-line noise mitigation measures.
2 Noise level measurements shall be made with slow meter response.
3 Noise level measurements shall be made with fast meter response.
Source: City of San Luis Obispo 1996.
City of San Luis Obispo Municipal Code, Title 9, Chapter 9.12 (Noise Control)
The City’s Municipal Code (Section 9.12.060) specifies noise standards for various
categories of land use. These limits, shown in Table 3.10-7, would apply to long-term
operation of the site, and are not applicable during construction. Prohibitions applied to
creating noise for maximum time periods from any source within the City are shown in
Table 3.10-8.
Where technically and economically feasible, construction activities shall be conducted so
that maximum noise levels at affected properties would not exceed 75 dBA for single-
family residential, 80 dBA for multi-family residential, and 85 dBA for mixed
residential/commercial land uses, as shown in Table 3.10-9 and Table 3.10-10 (Municipal
Code, Section 9.12.050). Except for emergency repair of public service utilities, or where
an exception is issued by the City Community Development Department, no operation of
tools or equipment used in construction, drilling, repair, alteration, or demolition work shall
occur daily between the hours of 7:00 PM and 7:00 AM, or any time on Sundays or
holidays, such that the sound creates a noise disturbance across a residential or commercial
property line.
3.10-16 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
Table 3.10-7. City of San Luis Obispo Exterior Noise Limits
Zoning Designation1 Time Period Maximum Acceptable
Noise Level (dBA2)3
Low- and Medium-Density Residential (R-1 and R-
2); Conservation/Open Space (C/OS)
10:00 PM – 7:00 AM 50
7:00 AM – 10:00 PM 55
Medium- and High-Density Residential (R-3 and R-
4)
10:00 PM – 7:00 AM 50
7:00 AM – 10:00 PM 55
Office and Public Facility (O and PF) 10:00 PM – 7:00 AM 55
7:00 AM – 10:00 PM 60
Neighborhood, Retail, Community, Downtown and
Tourist Commercial (C-N, C-R, C-C, C-D, C-T)
10:00 PM – 7:00 AM 60
7:00 AM – 10:00 PM 65
Service Commercial (C-S) Any Time 70
Manufacturing (M) Any Time 75
1 The classification of different areas of the community in terms of environmental noise zones shall be determined by
the Noise Control Office(r) based upon community noise survey data. Additional area classifications should be used as
appropriate to reflect both lower and higher existing ambient levels than those shown. Industrial noise limits are
intended primarily for use at the boundary of industrial zones rather than for noise reduction within the zone (Ord. 1032
§ 2 [part] 1985)
2 dBA (A-weighted decibel scale) emphasizes the range of sound frequencies that are most audible to the human ear
(between 1,000 and 8,000 Hertz).
3 Levels not to be exceeded more than 30 minutes in any hour.
Source: City of San Luis Obispo 2008.
Table 3.10-8. Maximum Time Periods for Increased Noise Levels
Noise Standard for
Existing Land Use
Maximum Time Period
Allowed
+0 dB 30 minutes/hour
+5 dB 15 minutes/hour
+10 dB 5 minutes/hour
+15 dB 1 minute/hour
+20 dB Any time
Source: City of San Luis Obispo 1996.
Table 3.10-9. Maximum Noise Levels for Nonscheduled, Intermittent, Short-Term
Operation (Less than 10 Days) of Mobile Equipment at Residential
Properties
Zoning Category Time Period Noise Level (dBA)
Single-Family Residential Daily 7:00 AM to 7:00 PM, except
Sundays and legal holidays
75
Multi-Family Residential 80
Mixed Residential/Commercial 85
Single-Family Residential 7:00 PM to 7:00 AM, all day Sunday
and legal holidays
50
Multi-Family Residential 55
Mixed Residential/Commercial 60
Source: City of San Luis Obispo 2008.
Froom Ranch Specific Plan 3.10-17
Draft EIR
3.10 NOISE
Table 3.10-10. Maximum Noise Levels for Repetitively Scheduled, Relatively Long-
Term Operation (10 Days or More) of Stationary Equipment at
Residential Properties
Zoning Category Time Period Noise Level (dBA)
Single-Family Residential Daily 7:00 AM to 7:00 PM, except
Sundays and legal holidays
60
Multi-Family Residential 65
Mixed Residential/Commercial 70
Single-Family Residential Daily 7:00 PM to 7:00 AM, including all
day Sunday and legal holidays
50
Multi-Family Residential 55
Mixed Residential/Commercial 60
Source: City of San Luis Obispo 2008.
3.10.3 Environmental Impact Analysis
3.10.3.1 Thresholds of Significance
Noise levels for the Project must comply with relevant noise policies, standards, and
ordinances. Appendix G of the CEQA Guidelines provides a set of screening questions that
address impacts related to noise. Specifically, the Guidelines state that a proposed project
may have a significant adverse impact related to noise if the project would:
a) Result in the generation of a substantial temporary or permanent increase in
ambient noise levels in the vicinity of the project in excess of standards established
in the local General Plan or noise ordinance, or applicable standards of other
agencies;
b) Result in the generation of excessive groundborne vibration or groundborne noise
levels; and
c) For a project located in the vicinity of a private airstrip or airport land use plan or,
where such a plan has not been adopted within 2 miles of a public airport or public
use airport, the project would expose people residing or working in the project area
to excessive noise levels.
3.10.3.2 Impact Assessment Methodology
This analysis was based on review and analysis of the City General Plan NE, the 2014
LUCE Update EIR, the County General Plan NE, the ALUP, the Federal Highway
Administration (FHWA) Highway Noise Prediction Model (FHWA-RD-77-108; FHWA
Model), the Applicant-prepared Acoustics Assessment for the Project (Appendix I), and
3.10-18 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
third party peer review of this Acoustics Assessment by the EIR consultant’s technical
noise specialist.
Construction Noise
Noise impacts related to construction traffic are assessed against noise levels permitted in
in the City Municipal Code Section 9.12.060. Noise associated with construction trips is
considered an intermittent rather than ongoing noise source, and impacts are accordingly
assessed in relation to Table 3.10-8, Maximum Time Periods for Increased Noise Levels.
Projected construction noise levels are analyzed based on typical construction equipment
required for Project development, construction BMPs, and distance between sensitive
receptors and anticipated construction activities.
The construction noise impact analysis assumes that Project development would occur over
a five-year period in four phases as detailed in Table 2-7, Section 2.0, Project Description.
Each phase of construction would involve different equipment and activities that would at
times overlap and potentially amplify noise levels. For example, the Project would require
import of 220,000 cy of soil and 2,300 cy of rock over five years. Utilizing a conservative
worst-case approach, the analysis assumes the use of smaller haul trucks and determined
Project development could require up to 22,000 heavy haul truck trips.2 Construction
traffic would also include earth and rock export/import, construction material deliveries,
and cement trucks.
Although precise numbers are not known, most of the approximately 22,000 heavy truck
trips, particularly those associated with hauling of earth and rock, are assumed to access
the site directly via the proposed main entrance at LOVR and Auto Park Way during the
21 months of Phase 1 and much of the 29 months of Phase 2. However, after occupancy of
residential units in Villaggio’s Lower Area toward the end of Phase 2, construction traffic,
including a smaller portion of heavy trucks, would access the proposed stormwater
detention basin area from Calle Joaquin and the Upper Terrace via Mountainbrook
Church’s private roadway. Potential impacts of haul trucks traffic on sensitive receptors
are analyzed based on the estimated noise level generated by a heavy haul or cement trucks
and the estimated distance of sensitive receptors from roadways carrying heavy haul truck
2 Estimated trips are based on a worst-case estimate for use of single box trucks. Haul truck capacities
typically range from 10 cy with a single box to 20 cy with a double box; use of larger single box trucks
with a 14-cy capacity is also common. Although major haul projects typically use larger load, 14 to 20 cy
load trucks, the final mix of truck sizes cannot be known and will be based on economics, availability,
and access routes, making precise numbers difficult to forecast.
Froom Ranch Specific Plan 3.10-19
Draft EIR
3.10 NOISE
traffic. Analysis of noise impacts from construction traffic trips are considered for two
potential construction haul routes:
1. Primary heavy haul truck trip access during Phase 1, much of Phase 2 and all of
Phase 4 would be through the main Project site entry at LOVR and Auto Park Way,
via LOVR. Trucks would use internal Local Road “C” or an interim road along this
alignment to access the site and the Upper Terrace during rough grading, but not
after the occupancy of units in the Lower Area of Villaggio in the later stages of
Phase 2. Construction traffic for the Madonna Froom Ranch residential and
commercial development would use the main Project entrance off LOVR.
2. Deliveries of construction materials and heavy equipment along with cement trucks
for foundation pours at the Upper Terrace would use the Mountainbrook Church
access route.
Construction noise levels were estimated using data published by the FHWA regarding the
noise-generating characteristics of typical construction equipment (see Table 3.10-11).
Construction noise levels diminish rapidly with distance, at a rate of approximately 6 dBA
per doubling of distance as equipment is generally stationary or confined to specific area
or access routes during construction. For example, a noise level of 86 dBA measured at 50
feet from the noise source would be reduced to 80 dBA at 100 feet from the source, and by
another 6 dBA (to 74 dBA) at 200 feet from the source. The noise levels from construction
at the offsite sensitive uses can be determined with the following equation from the High-
Speed Ground Noise and Vibration Impact Assessment, Final Report:
Lmax at sensitive use= Lmax at 50 feet – 20 Log(D/50)
Where: Lmax = noise level of noise source, D = distance from the noise source to the
receiver, and Lmax at 50 feet = noise level of source at 50 feet (U.S. Department of
Transportation 2012).
3.10-20 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
Table 3.10-11. Noise Ranges of Typical Construction Equipment
Construction Equipment Noise Levels in dBA Leq at 50 Feet
Back Hoe 73–95
Backup Alarm 88
Compressors 75–87
Concrete Mixer 75–88
Concrete Mixer Truck 79
Concrete Pump Truck 81
Concrete Pumps 81–85
Cranes (derrick) 86–89
Cranes (moveable) 75–88
Forklift 80
Generators 71–83
Haul Trucks (operation) 82–95
Haul Trucks (transportation) 85
Jackhammers 81–98
Paver 85–88
Pneumatic Tools 85
Pumps 68–72
Saws 72–82
Scraper/Grader 80–93
Semi-truck 85
Tractor 77–98
Vacuum Street Sweeper 82
Vibrator 68–82
Note: Machinery equipped with noise control devices or other noise-reducing design features does not generate the
same level of noise emissions as that shown in this table.
Sources: U.S. Department of Transportation 2013; FHWA 2006.
As set forth in the City Municipal Code, Section 9.12.050, construction activities within
the City are generally permissible between 7:00 AM and 7:00 PM on weekdays and
Saturdays. During these hours, the City permits long-term construction noise (in excess of
10 days) up to 70 dBA for commercial sensitive receptors, and 65 dBA for residential
sensitive receptors (refer to Table 3.10-9) or up to 20 dBA above normally acceptable
levels for any instantaneous noise event (refer to Table 3.10-8). Construction noise in
excess of these levels would be considered significant.
Froom Ranch Specific Plan 3.10-21
Draft EIR
3.10 NOISE
Vibration Levels Associated with Construction Equipment
Construction-related groundborne vibration levels were estimated using the 2013 Caltrans
Transportation and Construction Vibration Guidance Manual. Caltrans provides thresholds
of significance for vibration and a methodology for calculating vibration levels at a certain
distance from the generating source. Table 3.10-12 indicates vibration levels at which
humans would be affected. Table 3.10-13 identifies anticipated vibration velocity levels in
inches per second (in/sec) for standard types of construction equipment based on distance
from the receptor. Vibration impacts are assessed by estimating the vibration levels of
Project construction equipment and the distance of sensitive receptors to the vibration
source. Vibration impacts include those from excavation and other onsite construction
activities, as well as those associated with heavy haul trucks and concrete trucks.
Vibration levels at sensitive uses are determined using the following equation:
PPVProjected = PPVRef (25/D)n
Where: PPVRef = reference Peak Particle Velocity (in/sec) at 25 feet; D = distance from
equipment to the receiver in feet; n = 1.1 (a recommended conservative value pertaining
to attenuation rate of vibration through ground).
Table 3.10-12. Caltrans Vibration Annoyance Potential Criteria
Human Response Condition Maximum Vibration Level (in/sec)
for Transient Sources1
Maximum Vibration
Level (in/sec) for
Continuous/Frequent
Intermittent Sources
Barely perceptible 0.04 0.01
Distinctly perceptible 0.25 0.04
Strongly perceptible 0.9 0.10
Severe 2.0 0.4
1 Transit sources are defined as temporary sustained vibration of a mechanical system.
Source: Caltrans 2013.
Table 3.10-13. Vibration Source Levels for Construction Equipment
Construction
Equipment
Vibration Level (in/sec)
at 25 feet
Vibration Level (in/sec)
at 50 feet
Vibration Level (in/sec)
at 100 feet
Large Bulldozer 0.089 0.031 0.011
Loaded Trucks
(e.g., cement truck)
0.076 0.035 0.017
Jackhammer 0.035 0.016 0.008
Small Bulldozer 0.003 0.001 0.0004
Source: Caltrans 2013.
3.10-22 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
Operational Roadway Noise
Policy 1.4 of the City’s General Plan NE sets maximum noise exposure standards for noise-
sensitive land use specific to transportation noise sources (refer to Table 3.10-5). Noise in
excess of these levels would be considered significant. Project-generated increases in
roadway noise levels are considered in terms of potential to increase traffic volumes above
existing conditions. Project implementation would increase traffic and traffic-generated
noise on nearby roadways. In addition, future Project residents could be exposed to noise
generated on adjacent roadways.
Analysis of mobile source noise impacts includes review of LUCE Update EIR estimated
roadway noise levels in the Project vicinity for U.S. 101 and LOVR, and the Acoustics
Assessment prepared for the Project for existing and future roadway noise level estimates
within the Project site (Appendix I). As discussed in Section 3.10.1.2, Existing Noise
Environment, the LUCE Update EIR noise modeling does not account for physical
features, such as the Mountainbrook Church hill or hotels along Calle Joaquin, and
therefore overstates onsite noise levels from U.S. 101. The Acoustics Assessment appears
to most accurately reflect roadway noise levels from LOVR and is therefore used for
assessment of those impacts.
Stationary Noise Sources
Commercial operation noise levels are estimated using data regarding the noise-generating
characteristics of typical commercial equipment published by the FHWA, Environmental
Health Perspectives, and the U.S. Department of Transportation (see Table 3.10-14). The
City’s Municipal Code (Section 9.12.060) specifies noise exposure standards for future
uses within the Project site (Table 3.10-7). Noise generated from residential or other non-
commercial uses within and adjacent to the Project site are estimated based on the typical
dBA levels generated from urban uses, such as heating, ventilation, and air conditioning
(HVAC) equipment, delivery trucks, and other common uses, as well as the distance of
major adjacent noise generating sources (e.g., loading docks).
Froom Ranch Specific Plan 3.10-23
Draft EIR
3.10 NOISE
Table 3.10-14. Noise Ranges of Typical Commercial Equipment
Construction Equipment Noise Levels in dBA Leq at 50 Feet
Backup Alarm 881
HVAC 552
Forklift 80
Loudspeakers 89
Pneumatic Tools 85
Semi-truck 85
Vacuum Street Sweeper 82
Note: Machinery equipped with noise control devices or other noise-reducing design features does not generate the
same level of noise emissions as that shown in this table.
1While this represents typical backup alarm levels, alarms are required by law to be audible above ambient noise levels.
2This represents noise levels following typical attenuation methods including fitting with noise shielding cabinets or
placement on a roof or mechanical equipment room.
Sources: U.S. Department of Transportation 2013; FHWA 2006; Holzman 2011.
Assessment of potential impacts to future residents from roadways and adjacent uses
accounts for existing measured and mapped noise levels, as well as Project design features
intended to minimize impacts to future residents (e.g., inclusion of noise-reducing building
materials).
3.10.3.3 Project Impacts and Mitigation Measures
Potentially sensitive uses that could be affected by Project construction noise and vibration,
as well as Project operational noise impacts include Mountainbrook Church, hotels along
Calle Joaquin, passive recreational uses within the Irish Hills Natural Reserve, and future
noise-sensitive Project components, particularly residential uses in Villaggio’s Lower
Area, which are proposed to be occupied during intensive construction activities associated
with later phases. In addition, future Project residents could be exposed to existing and
future roadway noise and noise generated from adjacent commercial operations. Noise
from aircraft overflights do not generate high noise levels under current and projected
airport operations. Short-term construction and long-term operational impacts are analyzed
for the existing and future noise environment, and appropriate noise-control mitigation
measures are recommended below.
3.10-24 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
Table 3.10-15. Summary of Project Impacts
Noise Impacts Mitigation
Measures
Residual Significance
NO-1. Project construction, including site grading and
heavy truck trips, would generate noise levels that
exceed thresholds established in the City’s General
Plan Noise Element and Noise Guidebook resulting in
potentially significant impacts to proximate sensitive
receptors.
MM NO-1
MM NO-2
MM NO-3
Less than Significant
with Mitigation
NO-2. Project construction activities (e.g., excavation,
transportation of heavy equipment) could result in
exposure of sensitive receptors and buildings to
excessive groundborne vibration.
None Required Less than Significant
NO-3. Long-term operational noise impacts would
include higher roadway noise levels from increased
vehicle traffic generated by the Project, Project
operational noise, and exposure of future residents to
high noise levels that could result in the exceedance of
thresholds in the City’s General Plan Noise Element
and Noise Guidelines.
None Required Less than Significant
NO-4. Future residents and occupants of the Project
could be exposed to periodic high noise levels from
nearby commercial uses (e.g., delivery trucks, forklifts,
backup alarms) that would exceed City thresholds for
residential land uses.
MM NO-4 Less than Significant
with Mitigation
Impact NO‐1 Project construction, including site grading and heavy truck trips,
would generate noise levels that exceed thresholds established in the
City’s General Plan Noise Element and Noise Guidebook resulting in
potentially significant impacts to proximate sensitive receptors (Less
than Significant with Mitigation).
Project construction would extend over a five-year period and include approximately
570,000 cy of grading, with 220,000 cy of imported fill for the construction of proposed
development within the Project site, including 404 senior housing units within Villaggio
and up to 174 multi-family residential units, with over 2 miles of new roads and driveways,
utilities, and major drainage improvements, including realignment and widening of Froom
Creek. Each phase of construction would involve different equipment and activities that
would at times overlap and potentially amplify construction-related noise levels. Utilizing
a conservative worst-case approach, it is assumed that Project construction would utilize
smaller haul trucks, requiring up to 22,000 heavy haul truck trips for import/export of fill
Froom Ranch Specific Plan 3.10-25
Draft EIR
3.10 NOISE
material.3 Construction traffic would also include earth and rock export/import,
construction material deliveries, and cement trucks. The analysis assumes these trips would
occur within the Project site. However, after occupancy of residential units in Villaggio’s
Lower Area toward the end of Phase 2, construction traffic, including a smaller portion of
heavy trucks, would access the proposed stormwater detention basin area from Calle
Joaquin and the Upper Terrace via Mountainbrook Church’s private roadway.
Construction activities would generate increased noise that could impact surrounding uses,
particularly the use of earth moving equipment (e.g., bulldozers) and heavy haul trucks.
Construction noise levels vary depending on the amount and types of equipment used,
timing, and location of the activity in relation to the receptor (refer to Table 3.10-11).
Site preparation and grading would involve roughly 60 acres and occur in different
locations in Phases 1 through 3. Rough grading and transport of excess material within the
site, as well as import of more than 220,000 cy of fill and rock by heavy haul trucks during
these phases, would generate increased onsite and offsite noise levels. High levels of
construction noise would be generated by excavation equipment, internal haul truck trips,
and importation of fill from offsite. Grading and importation of fill would initially precede
and then be overlapped with construction of roadways, building pads, and utilities.
Rough grading and site preparation during Phases 1 through 3 would generate the highest
construction noise levels due to operation of heavy equipment and heavy haul trucks.
Specifically, rough grading, heavy truck trips, and construction in areas of the site
proximate to sensitive receptors (such as hotels along Calle Joaquin, the Irish Hills Natural
Reserve, and Mountainbrook Church) would generate potential impacts. Noise would also
occur from sources such as backup warning devices, which would be audible offsite.
Construction activities proximate to Calle Joaquin, including realignment of Froom Creek
and construction of the proposed stormwater detention basin and Lower Area of Villaggio
could impact sensitive receptors, such as hotel guests. Periodic maximum construction
noise levels are estimated to be as high as 85 dB at the nearest hotel building and 81 dB at
the nearest hotel pool. Construction close to Mountainbrook Church (e.g., the emergency
access road, haul truck trips) could generate noise levels of up to 91 dB (Table 3.1-16).
3 Estimated trips are based on a worst-case estimate for use of single box trucks. Haul truck capacities
typically range from 10 cy with a single box to 20 cy with a double box; use of larger single box trucks
with a 14-cy capacity is also common. Although major haul projects typically use larger load 14- to 20-
cy load trucks, the final mix of truck sizes cannot be known as it will be based on economics,
availability, and access routes, making precise numbers difficult to forecast.
3.10-26 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
Generally, noise levels generated by construction activities would be reduced by 20 to 30
dB within structures, depending on building materials.
Hikers, mountain bikers, and other users of the trails in the Irish Hills Natural Reserve
would also be exposed to noise impacts from all phases of Project construction. Depending
upon the phase of the Project, noise levels for trail users could reach 90 dBA with users
exposed to such noise levels for 15 to 30 minutes depending upon the trail and mode of use
(e.g., walking vs. mountain bike).
In addition, the Project phasing would allow occupancy of the Lower Area of Villaggio to
be occupied as early as 2022. Occupancy would precede later construction phases of the
Upper Terrace and Madonna Froom Ranch. While grading of the site would be complete
by 2022, fine grading and vertical construction of the Upper Terrace and Madonna Froom
Ranch would continue between 2022 and 2025, which would generate noise from trucks
and heavy construction equipment. Senior independent living residences, the Villaggio
Health Care Administration building, and senior assisted living facilities occupied in 2022
would be considered sensitive receptors to noise from Project construction. Grading, onsite
transport of cut material between the Upper Terrace and Madonna Froom Ranch areas, and
import of offsite fill to the Madonna Froom Ranch Area would potentially generate
excessive noise levels from heavy construction equipment and heavy haul trucks.
To protect future residents in Villaggio’s Lower Area from excessive construction noise
generated during Phases 3 and 4 (see Section 2.0, Project Description), the Applicant
proposes to strategically schedule grading of the Upper Terrace (Phase 3) to occur at the
same time as grading activities associated with Phase 1 and 2. All major grading and
earthmoving, including balancing soils within the Project site, would occur prior to
occupancy of any units within the Specific Plan area. Once occupancy begins, the Project
would reroute construction trips to the Upper Terrace, including any heavy haul or
materials delivery trips, along Calle Joaquin to the Mountainbrook Church driveway and
parking lot instead of through the local roads constructed to serve the Project. This
circulation approach would move sources of substantial construction noise offsite and away
from sensitive receptors residing onsite within the Lower Area once it is constructed. This
proposed construction phasing would therefore reduce the potential for exposure of
sensitive elderly populations to the most intensive construction activities and noise levels
associated with development under the Project.
Overall, Project construction maximum noise levels could reach as high as 89 to 92 dBA
at surrounding sensitive uses, including hotels along Calle Joaquin, Mountainbrook Church
Froom Ranch Specific Plan 3.10-27
Draft EIR
3.10 NOISE
and within the Irish Hills Natural Reserve (see Table 3.10-16). The City Municipal Code
permits construction noise up to 70 dBA for commercial sensitive receptors and up to 20
dBA above normally acceptable levels for any instantaneous noise event. Project
construction activities could exceed these thresholds both in peak noise and duration;
therefore, impacts are potentially significant.
Table 3.10-16. Maximum Estimated Outdoor Construction Peak Noise Levels at
Sensitive Receptors (Unmitigated)
Mountainbrook
Church
Nearest Hotel
Building
Nearest Hotel
Pool
Neil Havlik Way
Trail
Minimum distance
from construction
activity (feet)
60 100 140 70
Construction Noise
(dBA Lmax) 91 92 89 90
Note: Noise levels at sensitive uses were determined with the following equation from the High-Speed Ground Noise
and Vibration Impact Assessment, Final Report: Lmax = Lmax at 50 feet. – 20 Log(D/50), where Lmax = noise level of
noise source, D = distance from the noise source to the receiver, Lmax at 50 feet = noise level of source at 50 feet. Noise
levels represent the lower and upper limits of graders as displayed in Table 3.10-11. Noise levels have been rounded up
to the nearest whole number.
Source: U.S. Department of Transportation 2012.
Mitigation Measures
MM NO-1 Except for emergency repair of public service utilities, or where an
exception is issued by the Community Development Department, no
operation of tools or equipment used in construction, drilling, repair,
alteration, or demolition work shall occur between the hours of 7:00 PM
and 7:00 AM, or any time on Sundays, holidays, or after sunset, such that
the sound creates a noise disturbance that exceeds 75 dBA for single-family
residential uses, 80 dBA for multi-family residential uses, and 85 dBA for
mixed residential/commercial land uses, as shown in Table 3.10-9 and
Table 3.10-10, across a residential or commercial property line.
Requirements and Timing. Plans submitted for grading and building
permits shall clearly indicate construction hours and shall be submitted to
the City for approval prior to grading and building permit issuance for each
Project phase. To ensure response to and resolution of potential public noise
nuisance complaints, plans submitted for grading and building permits shall
clearly identify the Project’s construction manager (or similar) and 24-hour
contact information. At the pre-construction meeting required for all phases
of grading and development, all construction workers shall be briefed on
3.10-28 Froom Ranch Specific Plan
Draft EIR
3.10 NOISE
restricted construction hour limitations. A workday schedule shall be
adhered to for the duration of construction for all phases.
Monitoring. The Applicant’s permit compliance monitoring staff shall
perform periodic site inspections to verify compliance with activity
schedules and respond to complaints.
MM NO-2 For all construction activity at the Project site, noise attenuation techniques
shall be employed to ensure that noise levels are maintained within levels
allowed by the City of San Luis Obispo Municipal Code, Title 9, Chapter
9.12 (Noise Control). Such techniques shall include:
Sound blankets on noise-generating equipment.
Stationary construction equipment that generates noise levels above
65 dBA at the Project boundaries shall be shielded with a barrier
that meets a sound transmission class (a rating of how well noise
barriers attenuate sound) of 25.
All diesel equipment shall be operated with closed engine doors and
shall be equipped with factory-recommended mufflers.
Temporary sound barriers shall be constructed between
construction sites and affected uses.
Requirements and Timing. The Applicant shall designate the proposed
area of operation of stationary construction equipment and depict acoustic
shielding around these areas on building and grading plans. Equipment and
shielding shall be installed prior to construction and remain in the
designated location throughout construction activities. Construction plans
shall identify Best Management Practices (BMPs) to be implemented
during construction. All construction workers shall be briefed at a pre-
construction meeting on how, why, and where BMP measures are to be
implemented. BMPs shall be identified and described for submittal to the
City for review and approval prior to building or grading permit issuance.
BMPs shall be adhered to for the duration of the Project. Construction plans
shall include truck routes and shall be submitted to the City prior to grading
and building permit issuance for each Project phase.
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3.10 NOISE
Monitoring. City staff shall ensure compliance throughout all construction
phases. The Applicant’s permit compliance monitoring staff shall perform
periodic site inspections to verify compliance with activity schedules.
MM NO-3 The Applicant shall inform landowners and business operators at
properties within 300 feet of the Project site of proposed construction
timelines and noise complaint procedures to minimize potential annoyance
or nuisance complaints related to construction noise no less than 10 days
prior to initiation of any grading and construction activity for any Phase.
The notice shall include the name and contact information of the Project’s
construction manager and contact information for the City’s Community
Development Department.
Requirements and Timing. The Applicant shall provide and post signs
stating these restrictions and the Project’s construction manager’s name and
contact information at construction site entries. Signs shall be posted prior
to commencement of construction and maintained throughout construction
of any Phase. The construction schedule and mailing list shall be submitted
to the City Community Development Department 10 days prior to initiation
of any earth movement.
Monitoring. City staff shall ensure compliance throughout all construction
phases. The Applicant’s permit compliance monitoring staff shall perform
periodic site inspections to verify compliance with activity schedules and
respond to complaints.
Residual Impact
Noise from construction activities associated with Impact NO-1 would be reduced with
implementation of MM NO-1 through -3. These measures require that the Applicant limit
certain construction activities, provide noise attenuation measures to reduce perceived
interior and exterior noise levels, and notice nearby landowners of construction activities
and establish methods for addressing complaints. These measures, particularly MM NO-2,
would ensure construction noise levels are reduced to levels acceptable under City
standards. Therefore, residual impacts to Impact NO-1 would be less than significant.
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3.10 NOISE
Impact NO-2 Project construction activities (e.g., excavation, transportation of heavy
equipment) could result in exposure of sensitive receptors and
buildings to excessive groundborne vibration (Less than Significant).
Project construction could increase exposure of sensitive receptors to excessive vibration
levels. Based on Caltrans vibration criteria in Table 3.10-12 and Table 3.10-13, sensitive
receptors within 100 feet of construction activities could be subject to excessive vibration
from construction equipment. Sensitive receptors would include Mountainbrook Church
and hotels along Calle Joaquin.
Based on the distance and type of anticipated construction equipment and activities, these
sensitive receptors could experience periodic vibrations up to 0.047 in/sec. As construction
would be a frequent source of vibration for extended periods, this would be distinctly
perceptible. However, vibration levels experienced by offsite sensitive receptors would not
exceed the threshold of 0.10 in/sec. These vibrations would be temporary and intermittent
due to the nature of construction, and would only occur during the hours of construction,
generally 7:00 AM to 7:00 PM except for Sundays and holidays.
With regard to onsite sensitive receptors, as discussed above, to protect future residents in
Villaggio’s Lower Area from excessive construction noise and vibrations generated during
Phases 3 and 4 (see Section 2.0, Project Description), the Applicant proposes to
strategically schedule grading of the Upper Terrace (Phase 3) to occur at the same time as
grading activities associated with Phase 1 and 2, to avoid construction-related impacts of
later phases on Lower Area Villaggio occupants. Once occupancy begins, the Project
would reroute construction trips to the Upper Terrace via Calle Joaquin to the
Mountainbrook Church driveway and parking lot instead of through the local roads
constructed to serve the Project. This circulation approach would move sources of
construction vibration offsite and away from sensitive receptors residing onsite within the
Villaggio Lower Area once it is constructed. This proposed construction approach would
reduce potential for exposure of sensitive elderly populations to the most intensive
construction activities and groundborne vibrations associated with development under the
Project.
Because anticipated vibration levels would be substantially lower than thresholds
established by Caltrans (See Table 3.10-12), vibration impacts to offsite sensitive receptors
as a result of construction would be less than significant.
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3.10 NOISE
Impact NO-3 Long-term operational noise impacts would include higher roadway
noise levels from increased vehicle traffic generated by the Project,
Project operational noise, and exposure of future residents to high noise
levels that could result in the exceedance of thresholds in the City’s
General Plan Noise Element and Noise Guidelines (Less than
Significant).
Increased Roadway Noise
The Project would increase traffic on U.S. 101 and LOVR and could contribute to increased
noise levels from traffic. Under typical circumstances, projected traffic volumes generally
need to double over existing volumes in order for associated noise levels to increase by
approximately 3 dBA – the increase in noise level that is generally perceptible to the human
ear. As depicted in Table 3.10-17, projected ADT on LOVR are estimated to increase by
approximately 16.7 percent as a result of this Project, with an associated increase of less
than 1.0 dBA along this roadway. Project generated trips on U.S. 101 are expected to
increase by approximately 2.4 percent, which is similarly associated with a less than 1.0
dBA increase. Increased traffic ADTs along Calle Joaquin would be negligible with no
perceptible increase in noise levels. Given marginal Project-generated increases in traffic
and associated roadway noise levels along U.S. 101, LOVR, and Calle Joaquin, the Project
would not result in a significant contribution to the existing noise environment which
would result in exceedance of noise standards at nearby offsite receptors. Further, given
the Project would not expose future residents to unacceptable noise levels generated at
nearby roadways, traffic-related noise impacts are considered less than significant.
Table 3.10-17. Projected Traffic and Noise Level Increases along Adjacent
Roadways
Roadway Segment Existing ADT Projected ADT (%
increase)
Projected Noise Level
Increase (dBA)
LOVR 31,000 5,183 (16.7%) < 1
U.S. 101 80,000 1,555 (2.4%) < 1
Notes: Projected noise level increases were estimated from projected increases in ADT based on the following formula:
dBA=10Log10 (Projected ADT/Existing ADT).
Source: Caltrans 2017; City of San Luis Obispo 2016.
Exposure of Future Project Residents to High Noise Levels
Roadways near the Project site experience high levels of traffic that could result in noise
impacts to future sensitive receptors onsite. The portion of U.S. 101 adjacent to the Project
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site carries up to 80,000 ADTs and is located approximately 940 feet from the nearest
proposed residential building (in the Lower Area of Villaggio). LOVR also lies adjacent to
the Project site and carries approximately 31,000 ADTs. LOVR is located approximately
170 feet from the nearest residential unit in Villaggio’s Lower Area, approximately 300
feet from proposed health care facilities within Villaggio’s Lower Area, and approximately
170 feet from the nearest proposed multi-family residential unit in Madonna Froom Ranch.
Maximum allowable noise exposure resulting from transportation sources for residences,
hotels, and office buildings within the City is 60 dBA in exterior areas and 45 dBA within
interior spaces (See Table 3.10-5). Maximum allowable exposure of neighborhood parks
within the City is 65 dBA. The Acoustics Assessment prepared for the Project site modeled
the 60 dBA noise contour to be outside of these residential areas and proposed
neighborhood park and estimates that residential land uses would be approximately 42 to
57 dBA. Noise levels at the proposed neighborhood park are estimated to be 42 to 51 dBA
(Appendix I). Therefore, roadway noise levels would not exceed City standards for exterior
and interior noise levels under implementation of the Project. Associated impacts are
considered less than significant.
Operational Activities
Under the Project, long-term operational noise impacts would include noise from operation
of HVAC systems, landscaping and maintenance activities, and other typical residential
and commercial noise-generating uses.
Noise levels from commercial HVAC equipment can reach 100 dBA at a distance of 3 feet
U.S. EPA 1971); however, these units are typically fitted with noise shielding cabinets,
placed on the roof or in mechanical equipment rooms to reduce noise levels. Noise from
mechanical equipment associated with operation of the Project is required to comply with
the CBC requirements pertaining to noise attenuation. Therefore, with the application of
these noise reduction techniques, noise from these pieces of equipment does not typically
exceed 55 dBA at 50 feet, and would not exceed 45 dBA CNEL in any habitable room as
required by Title 24 of the CBC. As such, the operation of HVAC systems would not
exceed City exterior noise limits (see Table 3.10-7).
Landscaping and maintenance activities may include the use of equipment such as noise-
compliant leaf blowers or hedge trimmers, which would reach levels of 65 dBA at 50 feet.
Maximum permissible noise levels for nonscheduled, intermittent, short-term operation of
mobile equipment on multi-family residential properties from 7:00 AM to 7:00 PM,
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3.10 NOISE
excepting Sundays and holidays, ranges from 80 to 85 dBA (see Table 3.10-9). Expected
noise levels of equipment would be further reduced due to the fact that the nearest noise-
sensitive receptor is located 100 feet away.
The noise impacts from operation of the proposed development would be typical of similar
uses and would not constitute a substantial increase in ambient noise levels at offsite
locations and therefore would not exceed interior or exterior ambient noise thresholds at
offsite locations. Therefore, impacts related to the operation of stationary equipment and
site maintenance activities resulting from the Project would be less than significant.
Impact NO-4 Periodic high noise levels from nearby commercial uses (e.g., delivery
trucks, forklifts, backup alarms) may exceed City thresholds for
residential land uses (Less than Significant with Mitigation).
Residential uses of the Madonna Froom Ranch neighborhood could be exposed to periodic
high noise levels from commercial operations in the Irish Hills Plaza Shopping Center,
particularly from loading dock operations. Commercial facilities within the Irish Hills
Plaza support regular deliveries by large semi-trucks that can occur from 6:00 AM to 9:00
PM and generate noise from semi-trucks, refrigeration units, forklifts, and loudspeakers.
Additionally, backup alarms are required and would also create intermittent high noise
levels. General maintenance activities for the Irish Hills Plaza, including vacuum street
sweeping and dump truck circulation, would also generate intermittent peak noise.
Sensitive receptors that would be potentially affected by intermittent high noise levels from
adjacent commercial uses include the proposed neighborhood park, hotel, retail/office
spaces, and residents in the Madonna Froom Ranch neighborhood. Proposed residences
along the northwestern Project boundary and the proposed park would be located within
80 to 220 feet of the Home Depot loading dock and garden shop. The proposed hotel and
retail and office spaces are located within 175 to 250 feet of the TJ Maxx and Whole Foods
loading docks, while proposed multi-family residences are within 440 feet. Given these
intervening distances and noise levels from commercial operations, intermittent exterior
noise levels could reach up to 76 dBA at some of the proposed Madonna Froom Ranch
residences, 85 dBA within the proposed public park, 77 dB at the proposed hotel, and 74
dB at the proposed retail and office spaces (see Table 3.10-18). While noise levels from
HVAC equipment for offsite commercial facilities can reach up to 100 dBA, units
compliant with CBC noise attenuation requirements do not typically exceed 55 dBA at 50
feet and would not have a notable impact on the Project site.
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Automobile dealerships and associated automobile repair facilities located across LOVR
also have the potential to generate noise impacts. Noise sources resulting from these
facilities include outdoor loudspeakers and automobile service activities (e.g., pneumatic
air guns). Future onsite sensitive receptors potentially impacted by automobile dealership
generated noise would include the proposed Villaggio Lower Area health care facilities
located approximately 550 feet away and Madonna Froom Ranch multi-family housing
located approximately 370 feet away. Given intervening distances and maximum
equipment noise levels, periodic exterior noise levels from these sources could reach up to
68 dBA at the proposed Health Care Administration Building and 72 dBA at the proposed
multi-family housing units. However, given its intermittent nature and distance from the
site, automobile dealership noise would be considered a nuisance, but less than significant.
Irish Hills Plaza loading dock receives regular deliveries by large semi-trucks, as well as
deliveries from smaller vendors with variable schedules and frequency. Approximately 82
average weekly deliveries via semi-trucks to loading docks adjacent to future sensitive
receptors, as well as multiple smaller deliveries (e.g., UPS, FedEx) could lead to substantial
noise impacts in excess of adopted City standards. In addition to the noise resulting from
operation of semi-trucks, deliveries generate additional noises from equipment such as
refrigeration units, forklifts, loudspeakers and backup alarms. As presented in Table 3.10-
18, typical noise generated by such activities could range from 68 to 85 dB throughout the
Madonna Froom Ranch development. While noise generated by loading dock operations
would be heard in exterior areas of the proposed hotel, retail/office uses, and health care
facilities, the maximum noise level is not projected to exceed City standards. However,
loading dock operational noise could exceed exterior noise standards for the public park
and multi-family residential uses. Given the potential for these noise activities to exceed
exterior noise limits for park and residential uses within Madonna Froom Ranch, impacts
are considered potentially significant.
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3.10 NOISE
Table 3.10-18. Maximum Noise Level Estimates and Thresholds Resulting from
Nearby Commercial Activities
Park Hotel
MFR R-3-
SP
Residences
MFR R-4-
SP
Housing
Health
Care
Facilities
Retail/
Office
Maximum Noise Level
(dB) 85 77 76 72 68 74
City Exterior Noise
Limit – 30 minutes or
more1 (dBA)
60 65 60 55 55 60
City Exterior Noise
Limit – 1 minute2 (dBA) 75 80 75 70 70 75
1 Noise Standard for Land Use within Section 9.12.060 of the City Municipal Code. Levels not to be exceeded more
than 30 minutes in any hour.
2 Noise Standard for Land Use within Section 9.12.060 of the City Municipal Code. Levels not to be exceeded for more
than one minute in any hour.
MFR - Madonna Froom Ranch
Mitigation Measures
MM NO-4. Prior to approval of park and residential development within the Madonna
Froom Ranch area of the Specific Plan, the Applicant shall submit a
project-specific noise study that evaluates the potential for noise exposure
from adjacent commercial uses and identifies project-specific design
measures to attenuate exterior and interior noise consistent with the City’s
Noise Element and Noise Ordinance. If necessary to reduce noise within
acceptable levels, noise reduction measures may include a planted earthen
berm, sound wall, or similar noise attenuating feature along the site
boundary with Irish Hills Plaza, consistent with Policy 1.8.2 of the Noise
Element.
Requirements and Timing. The Applicant shall incorporate the above
mitigation within the final FRSP prior to adoption.
Monitoring. City staff shall ensure compliance with required site design
and noise reduction measures within the final FRSP prior to adoption and
shall confirm any required noise attenuation measures are shown on
construction plans prior to issuance of building permits.
Residual Impact
MM NO-4 would attenuate noise from adjacent commercial deliveries and loading areas,
ensuring that proposed residential and park uses would not be exposed to noise exceeding
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levels identified within Section 9.12.060 of the Municipal Code. Therefore, residual
impacts would be less than significant with mitigation.
3.10.3.4 Cumulative Impacts
Development of the Project in conjunction with future cumulative projects would
potentially result in an increase in construction-related and traffic-related noise sources in
the City.
Construction Impacts
The potential for cumulative construction-related impacts to occur is increased with the
Project’s five-year construction period. Construction-related noise and groundborne
vibration associated with the Project would potentially overlap with some cumulative
projects within Table 3.0-1 (that have not yet been approved or constructed). This includes
development of two automobile dealerships along Auto Park Way, Towne place Suites,
and the San Luis Ranch Specific Plan area. Construction noise generated by the Project
and other future development would be localized within the vicinity of the proposed
development areas. Project-related construction noise and vibration would be removed
from other construction activities and proposed projects pending in the vicinity. The
Project, along with other cumulative development projects, would be required to
implement site-specific measures to reduce construction-related noise to reduce impacts on
surrounding development. Implementation of such measures would ensure noise generated
from an individual site is adequately attenuated and would not contribute to cumulatively
significant impacts on surrounding uses. Larger cumulative development projects such as
the San Luis Ranch Specific Plan project, located approximately 1,800 feet north of the
Project site, are located far enough from the Project site that concurrent development
activities would not contribute to a cumulative substantial increase in ambient noise due to
distance of the noise generators and attenuation from intervening development. Therefore,
the Project’s construction-related noise and vibration impacts would not considerably
contribute to cumulative noise and vibration impacts from construction activities.
Cumulative impacts would be less than significant.
Operational Impacts
The Project, in combination with approved, pending, and proposed development within the
City, would contribute to an increase of long-term traffic and associated traffic noise, as
well as operational noise from the proposed new development. The Project does not
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propose any uses that would generate noise which would result in a perceptible increase in
ambient noise levels offsite, and the Project contribution to the cumulative noise
environment would be negligible. Implementation and buildout of the LUCE Update and
pending projects in the vicinity would increase traffic volumes and associated noise levels
along major transportation routes. The Project would also increase traffic and associated
noise levels with approximately 5,183 additional ADT along surrounding roadways such
as LOVR, Calle Joaquin, and U.S. 101, although these increases in ambient noise levels
would not result in a noticeable increase in noise levels (less than 1 dBA increase). As
discussed above, a perceptible increase in roadway noise levels would require traffic
volumes to nearly double over existing volumes. Cumulative projects in the area would
increase traffic levels and subsequent noise levels primarily on arterials and major
roadways by approximately 20 percent (Appendix J); therefore, the noise-related impacts
to residential and local streets would be nominal. Development of the Project and
implementation of the LUCE Update could cumulatively increase stationary source noise
levels; however, the City’s Noise Element and Municipal Code contain policies and
programs that would address and mitigate potential site-specific impacts for individual
projects in the future, including Noise Guidebook Policy 1.4 which requires noise created
by all new development be individually mitigated by each project so as not to exceed
acceptable outdoor noise levels. Due to requirement for compliance with existing
regulations, implementation of project-specific noise mitigation measures, and nominal
increases in the ambient noise environment from proposed cumulative development, this
cumulative impact would be considered less than significant.
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