HomeMy WebLinkAboutSDP 2023-0012; LEGOLAND CALIFORNIA PROJECT 2025; NOISE AND VIBRATION IMPACT ANALYSIS; 2023-07-31
CARLSBAD
CLOVIS
IRVINE
LOS ANGELES
PALM SPRINGS
POINT RICHMOND
RIVERSIDE
ROSEVILLE
SAN LUIS OBISPO
3210 El Camino Real, Suite 100, Irvine, California 92602 949.553.0666 www.lsa.net
MEMORANDUM
DATE: July 31, 2023
TO: Bill Hofman, Hofman Planning Associates
FROM: Jason Lui, Associate/Senior Noise Specialist
SUBJECT: Noise and Vibration Impact Analysis for the LEGOLAND California Project 2025 in
Carlsbad, California (LSA Project No. 20231502)
INTRODUCTION
This noise and vibration impact analysis has been prepared to evaluate the potential noise and
vibration impacts and reduction measures associated with the LEGOLAND California Project 2025
(project) in Carlsbad, California. This memorandum is intended to satisfy the City of Carlsbad’s (City)
requirements and the California Environmental Quality Act for a project‐specific noise and vibration
impact analysis by examining the impacts of the proposed uses on the project site and evaluating
the reduction measures that the project requires. All references cited in this memorandum are
included in Attachment A.
Project Location
The 2.38‐acre project site is located within the Legoland Theme Park in Carlsbad, San Diego County,
California. The project is at the site of the existing “Driving School” and “Junior Driving School”
attractions, which will be removed. The site is approximately 103,470 square feet (sf) [2.38 acres] in
size with a generally flat topography. Local access to the project site is provided by Legoland Drive
and Crossings Drive. The project location is shown in Figure 1 (all figures are provided in
Attachment B).
Project Description
The new attraction area will have a “space” theme where park guests will train for space
exploration, meet other intergalactic travelers, and blast off on missions into the LEGO Galaxy!
The proposed project would demolish the existing “Driving School” and “Junior Driving School”
attractions and redevelop the site with a new attraction called “Project Mars.” Existing site
development to be removed includes the driving school courses, queues, shade covers, a small retail
facility, and landscaping. Figure 2 illustrates the project site plan. The major components of the
proposed project are as follows:
Primary Ride: The ride consists of an indoor roller coaster housed inside a new single‐story,
32,319 sf, 44‐foot‐high pre‐manufactured steel building. Ancillary uses within the building
include the ride queue, a LEGO brick building attraction, retail, and maintenance, as well as
mechanical and storage spaces.
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Secondary Ride: This ride has three cantilever arms that are lifted in the air by hydraulic
actuators and carry a counter‐rotating gyro element holding four gondolas at each end. The
gondolas are designed to accommodate two riders to provide a capacity of up to 24 passengers.
A Playscape: This would be an approximately 1,755 sf exterior area featuring a children’s play
structure with an alien spaceship theme.
A Toddler Play Area (“Tot Spot”): The project also includes an approximately 1,234 sf exterior
area designed for the smallest guests, with LEGO DUPLO play features, shade cover, and seating.
Proposed site development will include grading, utilities, new hardscape, planting, and
retrofitting of existing recycled water irrigation systems.
Construction would include demolition, site preparation, grading, and building construction
activities. Construction of the proposed project is anticipated to commence in January 2024 and end
in March 2025.
CHARACTERISTICS OF SOUND
Noise is usually defined as unwanted sound. Noise consists of any sound that may produce
physiological or psychological damage and/or interfere with communication, work, rest, recreation,
and sleep.
To the human ear, sound has two significant characteristics: pitch and loudness. Pitch is generally an
annoyance, while loudness can affect the ability to hear. Pitch is the number of complete vibrations,
or cycles per second, of a wave resulting in the tone’s range from high to low. Loudness is the
strength of a sound that describes a noisy or quiet environment and is measured by the amplitude
of the sound wave. Loudness is determined by the intensity of the sound waves combined with the
reception characteristics of the human ear. Sound intensity refers to how hard the sound wave
strikes an object, which in turn produces the sound’s effect. This characteristic of sound can be
precisely measured with instruments. The analysis of a project defines the noise environment of the
project area in terms of sound intensity and its effect on adjacent sensitive land uses.
Measurement of Sound
Sound intensity is measured through the A‐weighted scale to correct for the relative frequency
response of the human ear. That is, an A‐weighted noise level deemphasizes low and very high
frequencies of sound similar to the human ear’s de‐emphasis of these frequencies. Decibels (dB),
unlike the linear scale (e.g., inches or pounds), are measured on a logarithmic scale, which is a scale
based on powers of 10.
For example, 10 decibels is 10 times more intense than 0 dB, 20 dB is 100 times more intense than
0 dB, and 30 dB is 1,000 times more intense than 0 dB. Thirty decibels (30 dB) represents 1,000
times as much acoustic energy as 0 dB. The decibel scale increases as the square of the change,
representing the sound pressure energy. A sound as soft as human breathing is about 10 times
greater than 0 dB. The decibel system of measuring sound gives a rough connection between the
physical intensity of sound and its perceived loudness to the human ear. A 10 dB increase in sound
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level is perceived by the human ear as only a doubling of the loudness of the sound. Ambient sounds
generally range from 30 dB (very quiet) to 100 dB (very loud).
Sound levels are generated from a source, and their decibel level decreases as the distance from
that source increases. Sound dissipates exponentially with distance from the noise source. For a
single point source, sound levels decrease approximately 6 dB for each doubling of distance from
the source. This drop‐off rate is appropriate for noise generated by stationary equipment. If noise is
produced by a line source (e.g., highway traffic or railroad operations), the sound decreases 3 dB for
each doubling of distance in a hard site environment; however, line source noise in a relatively flat
environment with absorptive vegetation decreases 4.5 dB for each doubling of distance.
There are many ways to rate noise for various time periods, but an appropriate rating of ambient noise
affecting humans also accounts for the annoying effects of sound. The equivalent continuous sound
level (Leq) is the total sound energy of time‐varying noise over a sample period. However, the
predominant rating scales for human communities in the State of California are the Leq and community
noise equivalent level (CNEL) or the day‐night average noise level (Ldn) based on A‐weighted decibels
(dBA). CNEL is the time‐varying noise over a 24‐hour period, with a 5 dBA weighting factor applied to
the hourly Leq for noises occurring from 7:00 p.m. to 10:00 p.m. (defined as relaxation hours), and a
10 dBA weighting factor applied to noises occurring from 10:00 p.m. to 7:00 a.m. (defined as sleeping
hours). Ldn is similar to the CNEL scale but without the adjustment for events occurring during the
evening hours. CNEL and Ldn are within 1 dBA of each other and are normally interchangeable. The City
uses the CNEL noise scale for long‐term noise impact assessment.
Other noise rating scales of importance when assessing the annoyance factor include the maximum
noise level (Lmax), which is the highest exponential time‐averaged sound level that occurs during a
stated time period. The noise environments discussed in this analysis for short‐term noise impacts
are specified in terms of maximum levels denoted by Lmax, which reflects peak operating conditions
and addresses the annoying aspects of intermittent noise. Lmax is often used together with another
noise scale, or noise standards in terms of percentile noise levels, in noise ordinances for
enforcement purposes. For example, the L10 noise level represents the noise level exceeded 10
percent of the time during a stated period. The L50 noise level represents the median noise level.
Half the time the noise level exceeds this level, and half the time, it is less than this level. The L90
noise level represents the noise level exceeded 90 percent of the time and is considered the
background noise level during a monitoring period. For a relatively constant noise source, the Leq
and L50 are approximately the same.
Noise impacts can be described in three categories. The first category includes audible impacts that
refer to increases in noise levels noticeable to humans. Audible increases in noise levels generally
refer to a change of 3 dB or greater because this level has been found to be barely perceptible in
exterior environments. The second category, potentially audible, refers to a change in the noise
level between 1 dB and 3 dB. This range of noise levels has been found to be noticeable only in
laboratory environments. The last category includes changes in noise levels of less than 1 dB, which
are inaudible to the human ear. Only audible changes in existing ambient or background noise levels
are considered potentially significant.
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Physiological Effects of Noise
Physical damage to human hearing begins at prolonged exposure to noise levels higher than 85 dBA.
Exposure to high noise levels affects the entire system, with prolonged noise exposure in excess of
75 dBA increasing body tensions, thereby affecting blood pressure and functions of the heart and
the nervous system. In comparison, extended periods of noise exposure above 90 dBA would result
in permanent cell damage. When the noise level reaches 120 dBA, a tickling sensation occurs in the
human ear, even with short‐term exposure. This level of noise is called the threshold of feeling. As
the sound reaches 140 dBA, the tickling sensation is replaced by the feeling of pain in the ear (the
threshold of pain). A sound level of 160–165 dBA will result in dizziness or loss of equilibrium. The
ambient or background noise problem is widespread and generally more concentrated in urban
areas than in outlying, less developed area. Table A lists definitions of acoustical terms, and Table B
shows common sound levels and their sources.
Table A: Definitions of Acoustical Terms
Term Definitions
Decibel, dB A unit of measurement that denotes the ratio between two quantities that are proportional to
power; the number of decibels is 10 times the logarithm (to the base 10) of this ratio.
Frequency, Hz Of a function periodic in time, the number of times that the quantity repeats itself in 1 second
(i.e., number of cycles per second).
A‐Weighted Sound
Level, dBA
The sound level obtained by use of A‐weighting. The A‐weighting filter deemphasizes the very
low‐ and very high‐frequency components of the sound in a manner similar to the frequency
response of the human ear and correlates well with subjective reactions to noise. (All sound levels
in this report are A‐weighted, unless reported otherwise.)
L01, L10, L50, L90 The fast A‐weighted noise levels that are equaled or exceeded by a fluctuating sound level 1%,
10%, 50%, and 90% of a stated time period.
Equivalent
Continuous Noise
Level, Leq
The level of a steady sound that, in a stated time period and at a stated location, has the same A‐
weighted sound energy as the time‐varying sound.
Community Noise
Equivalent Level,
CNEL
The 24‐hour A‐weighted average sound level from midnight to midnight, obtained after the
addition of 5 dBA to sound levels occurring in the evening from 7:00 PM to 10:00 PM and after
the addition of 10 dBA to sound levels occurring in the night between 10:00 PM and 7:00 AM.
Day/Night Noise
Level, Ldn
The 24‐hour A‐weighted average sound level from midnight to midnight, obtained after the
addition of 10 dBA to sound levels occurring in the night between 10:00 PM and 7:00 AM.
Lmax, Lmin The maximum and minimum A‐weighted sound levels measured on a sound level meter, during a
designated time interval, using fast time averaging.
Ambient Noise
Level
The all‐encompassing noise associated with a given environment at a specified time; usually a
composite of sound from many sources at many directions, near and far; no particular sound is
dominant.
Intrusive The noise that intrudes over and above the existing ambient noise at a given location. The relative
intrusiveness of a sound depends upon its amplitude, duration, frequency, and time of
occurrence and tonal or informational content, as well as the prevailing ambient noise level.
Source: Handbook of Acoustical Measurements and Noise Control (Harris 1991).
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Table B: Common Sound Levels and Their Noise Sources
Noise Source A‐Weighted Sound
Level in Decibels
Noise
Environments
Subjective
Evaluations
Near Jet Engine 140 Deafening 128 times as loud
Civil Defense Siren 130 Threshold of Pain 64 times as loud
Hard Rock Band 120 Threshold of Feeling 32 times as loud
Accelerating Motorcycle at a Few Feet Away 110 Very Loud 16 times as loud
Pile Driver; Noisy Urban Street/Heavy City Traffic 100 Very Loud 8 times as loud
Ambulance Siren; Food Blender 95 Very Loud —
Garbage Disposal 90 Very Loud 4 times as loud
Freight Cars; Living Room Music 85 Loud —
Pneumatic Drill; Vacuum Cleaner 80 Loud 2 times as loud
Busy Restaurant 75 Moderately Loud —
Near Freeway Auto Traffic 70 Moderately Loud —
Average Office 60 Quiet One‐half as loud
Suburban Street 55 Quiet —
Light Traffic; Soft Radio Music in Apartment 50 Quiet One‐quarter as loud
Large Transformer 45 Quiet —
Average Residence without Stereo Playing 40 Faint One‐eighth as loud
Soft Whisper 30 Faint —
Rustling Leaves 20 Very Faint —
Human Breathing 10 Very Faint Threshold of
Hearing
— 0 Very Faint —
Source: Compiled by LSA (2015).
FUNDAMENTALS OF VIBRATION
Vibration refers to ground‐borne noise and perceptible motion. Ground‐borne vibration is almost
exclusively a concern inside buildings and is rarely perceived as a problem outdoors, where the
motion may be discernible, but without the effects associated with the shaking of a building there is
less adverse reaction. Vibration energy propagates from a source through intervening soil and rock
layers to the foundations of nearby buildings. The vibration then propagates from the foundation
throughout the remainder of the structure. Building vibration may be perceived by occupants as the
motion of building surfaces, the rattling of items on shelves or hanging on walls, or a low‐frequency
rumbling noise. The rumbling noise is caused by the vibration of walls, floors, and ceilings that
radiate sound waves. Annoyance from vibration often occurs when the vibration exceeds the
threshold of perception by 10 vibration velocity decibels (VdB) or less. This is an order of magnitude
below the damage threshold for normal buildings. Typical sources of ground‐borne vibration are
construction activities (e.g., blasting, pile driving, and operating heavy‐duty earthmoving
equipment), steel‐wheeled trains, and occasional traffic on rough roads. Ground‐borne vibration
and noise from these sources are usually localized to areas within approximately 100 feet (ft) from
the vibration source, although there are examples of ground‐borne vibration causing interference
out to distances greater than 200 ft (see the Federal Transit Administration’s [FTA] 2018 Transit
Noise and Vibration Impact Assessment Manual [FTA Manual]). When roadways are smooth,
vibration from traffic, even heavy trucks, is rarely perceptible. It is assumed for most projects that
the roadway surface will be smooth enough that ground‐borne vibration from street traffic will not
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exceed the impact criteria; however, both construction of a project and freight train operations on
railroad tracks could result in ground‐borne vibration that may be perceptible and annoying.
Ground‐borne noise is not likely to be a problem because noise arriving via the normal airborne path
will usually be greater than ground‐borne noise. Ground‐borne vibration has the potential to disturb
people and damage buildings. Although it is very rare for train‐induced ground‐borne vibration to
cause cosmetic building damage, it is not uncommon for heavy‐duty construction processes (e.g.,
blasting and pile driving) to cause vibration of sufficient amplitudes to damage nearby buildings (FTA
2018). Ground‐borne vibration is usually measured in terms of vibration velocity, either the root‐
mean‐square (RMS) velocity or peak particle velocity (PPV). The RMS is best for characterizing
human response to building vibration, and PPV is used to characterize potential for damage. Decibel
notation acts to compress the range of numbers required to describe vibration. Vibration velocity
level in decibels is defined as:
Lv = 20 log10 [V/Vref]
where Lv is the VdB, “V” is the RMS velocity amplitude, and “Vref” is the reference velocity
amplitude, or 1 × 10‐6 inches/second (in/sec) used in the United States.
REGULATORY SETTING
Federal Guidelines
Federal Transit Administration
Noise. The construction noise criteria included in the FTA Manual (2018) were used to evaluate
potential construction noise impacts because Section 8.48.010 of the City’s Municipal Code does not
have daytime construction noise level limits for activities that occur within the specified hours.
Table C shows the FTA’s Detailed Assessment Daytime Construction Noise Criteria based on the
composite noise levels for each construction phase.
Table C: Detailed Assessment Daytime
Construction Noise Criteria
Land Use Daytime 1‐hour Leq (dBA)
Residential 80
Commercial 85
Industrial 90
Source: Transit Noise and Vibration Impact Assessment Manual (FTA 2018).
dBA = A‐weighted decibels
Leq = equivalent continuous sound level
Vibration. Vibration standards included in the FTA Manual (2018) were used to evaluate vibration
impacts because the City does not have vibration standards. Table D provides the criteria for
assessing the potential for interference or annoyance from vibration levels in a building, while
Table E lists the potential vibration building damage criteria associated with construction activities.
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Table D: Interpretation of Vibration Criteria for Detailed Analysis
Land Use Maximum
Lv (VdB)1 Description of Use
Workshop 90 Vibration that is distinctly felt. Appropriate for workshops and similar areas not
as sensitive to vibration.
Office 84 Vibration that can be felt. Appropriate for offices and similar areas not as
sensitive to vibration.
Residential Day 78 Vibration that is barely felt. Adequate for computer equipment and low‐power
optical microscopes (up to 20×).
Residential Night and
Operating Rooms 72
Vibration is not felt, but ground‐borne noise may be audible inside quiet rooms.
Suitable for medium‐power microscopes (100×) and other equipment of low
sensitivity.
Source: Transit Noise and Vibration Impact Assessment Manual (FTA 2018).
1 As measured in ⅓‐octave bands of frequency over the frequency range 8 to 80 Hertz.
FTA = Federal Transit Administration
LV = velocity in decibels
VdB = vibration velocity decibels
Table E: Construction Vibration Damage Criteria
Building Category PPV (in/sec) Approximate LV (VdB)1
Reinforced concrete, steel, or timber (no plaster) 0.50 102
Engineered concrete and masonry (no plaster) 0.30 98
Non‐engineered timber and masonry buildings 0.20 94
Buildings extremely susceptible to vibration damage 0.12 90
Source: Transit Noise and Vibration Impact Assessment Manual (FTA 2018).
1 RMS vibration velocity in decibels (VdB) re 1 µin/sec.
µin/sec = microinches per second
FTA = Federal Transit Administration
in/sec = inches per second
LV = velocity in decibels
PPV = peak particle velocity
RMS = root‐mean‐square
VdB = vibration velocity decibels
Local Regulations
City of Carlsbad
Noise Element of the General Plan. The Noise Element of the City’s General Plan (2015) has
established allowable exterior and interior noise exposure for various land uses, noise standards
from non‐transportation noise sources (stationary noise sources), and policies to meet the City’s
noise‐related goals. The allowable exterior and interior noise exposure for each land use are
summarized in Table F and noise standards from stationary noise sources are shown in Table G.
Applicable goals and policies for the proposed project are listed below.
Goal 5‐G.3. Guide the location and design of transportation facilities, industrial uses and other
potential noise generators to minimize the effects of noise on adjacent land uses.
Policy 5‐P.5. Noise Generation. As part of development project approval, require that noise
generated by a project does not exceed standards established in Table 5‐3 (Table G).
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Table F: Allowable Noise Exposure1
Land Use
Outdoor Activity Areas2,3
(dBA CNEL)
Interior Spaces
(dBA CNEL)
Residential 604 45
Motels, Hotels 65 45
Hospitals, Residential Care Facilities, Schools,
Libraries, Museums, Churches, Day Care Facilities 65 45
Playgrounds, Parks, Recreation Uses 65 50
Commercial and Office Uses 65 50
Industrial Uses 70 65
Source: City of Carlsbad General Plan Noise Element (September 2015).
1 Development proposed within the McClellan‐Palomar Airport Area of Influence shall also be subject to the noise compatibility
policies contained in the ALUCP.
2 The standard does not apply for nonresidential uses where an outdoor activity area is not proposed. Where the location of
outdoor activity areas is unknown, the exterior noise level standard shall be applied to the property line of the receiving use.
3 Where it is not possible to reduce noise in outdoor activity areas to the allowable maximum, levels up to 5 dBA higher may be
allowed provided that available exterior noise level reduction measures have been implemented and interior noise levels are
in compliance with this table.
4 An exterior noise exposure level of 65 dBA CNEL is allowable for residential uses in a mixed‐use project and for residential
uses within the McClellan‐Palomar Airport Area of Influence, pursuant to the noise compatibility policies contained in the
ALUCP.
ALUCP = Airport Land Use Consistency Plan
CNEL = Community Noise Equivalent Level
dB = decibels
dBA = A‐weighted decibels
Table G: Performance Standards for Non‐Transportation Sources
(As Measured at Property Line of Source/Sensitive Land Use)
Noise Level Descriptor
Daytime
(7:00 a.m. to 10:00 p.m.)
Nighttime
(10:00 p.m. to 7:00 a.m.)
Hourly Leq, dBA 55 45
Maximum Level, dBA 75 65
Source: City of Carlsbad General Plan Noise Element (September 2015).
Note: Each of the noise levels specified above shall be lowered by 5 dBA for simple‐tone noises, noises
consisting of speech or music, or recurring impulsive noises.
dB = decibels
Leq = Equivalent continuous sound level
Municipal Code. Section 8.48.010 of the City’s Municipal Code prohibits construction after 6:00 p.m.
on any day and before 7:00 a.m. Monday through Friday and before 8:00 a.m. on Saturday.
Construction is prohibited on Sundays and federal holidays.
EXISTING SETTING
Land Uses in the Project Vicinity
The project site is surrounded by a business park to the west across Legoland Drive and the existing
theme park immediately to the north, east, and south. Noise‐sensitive land uses closest to the
project site include residences located approximately 2,900 ft to the south and a resort hotel
approximately 780 ft to the south.
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Overview of the Existing Noise Environment
The primary existing noise sources in the project area are transportation facilities. Traffic on
Legoland Drive and other local streets contributes to the ambient noise levels in the project vicinity.
Noise from motor vehicles is generated by engines, interaction between tires and the road, and
vehicle exhaust systems. In addition, business park industrial activities and McClellan‐Palomar
airport operations contribute to the background ambient noise in the project vicinity.
Existing Aircraft Noise
The McClellan‐Palomar Airport is 1.3 miles east of the project site. The future airport noise contour
map contained in the McClellan‐Palomar Airport Land Use Compatibility Plan (SDCALUC 2011) shows
that the project site is located within the 60 to 65 dBA CNEL noise contour. Also, there are no
private airstrips within 2 miles of the project site. The project site is a theme park, and the land use
would be similar to recreational and commercial use, which would be considered compatible uses
based on the McClellan‐Palomar Airport noise compatibility criteria and the allowable noise
exposure levels from the City’s Noise Element of the General Plan. In addition, the project would not
change the noise exposure levels for people working in the project area. Therefore, the project
would not expose people working in the project area to excessive noise levels, and this topic is not
further discussed.
IMPACTS
Short‐Term Construction Noise Impacts
Two types of short‐term noise impacts would occur during project construction. The first type would
be from construction crew commutes and the transport of construction equipment and materials to
the project site and would incrementally raise noise levels on roadways leading to the project site.
The pieces of construction equipment for construction activities would move on site, would remain
for the duration of each construction phase, and would not add to the daily traffic volume in the
project vicinity. Although there would be a relatively high single‐event noise exposure potential
causing intermittent noise nuisance (passing trucks at 50 ft would generate up to a maximum of 84
dBA), the effect on longer‐term ambient noise levels would be small because the number of daily
construction‐related vehicle trips is small compared to existing daily traffic volume on roadways
leading to the project site. The grading phase would generate the most trips out of all of the
construction phases, at a Passenger Car Equivalent (PCE) of 263 trips per day based on the California
Emissions Estimator Model (CalEEMod) (Version 2022.1) results contained in Attachment B of the
Air Quality Impact Analysis Memorandum for the LEGOLAND California Project 2025 (LSA 2023).
Roadways leading to the project site would have traffic volumes higher than 263, and construction‐
related traffic would not double the traffic volume on roadways leading to the project. It takes a
doubling of traffic to increase traffic noise levels by 3 dBA. Therefore, construction‐related traffic
would not increase noise by 3 dBA. A noise level increase of less than 3 dBA would not be
perceptible to the human ear in an outdoor environment. Therefore, no short‐term, construction‐
related impacts associated with worker commutes and transport of construction equipment and
material to the project site would occur, and no noise reduction measures would be required.
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The second type of short‐term noise impact is related noise generated from construction activities.
Construction is performed in discrete steps, each of which has its own mix of equipment and,
consequently, its own noise characteristics. The proposed project anticipates demolition, site
preparation, grading, building construction, paving, and architectural coating phases of construction.
These various sequential phases change the character of the noise generated on a project site.
Therefore, the noise levels vary as construction progresses. Despite the variety in the type and size
of construction equipment, similarities in the dominant noise sources and patterns of operation
allow construction‐related noise ranges to be categorized by work phase. Table H lists the Lmax
recommended for noise impact assessments for typical construction equipment included in the
Federal Highway Administration’s (FHWA) Highway Construction Noise Handbook (2006), based on a
distance of 50 ft between the equipment and a noise receptor.
Table H: Typical Construction Equipment Noise Levels
Equipment Description Acoustical Usage Factor1 (%) Maximum Noise Level (Lmax) at 50 ft2
Backhoe 40 80
Compactor (ground) 20 80
Compressor 40 80
Crane 16 85
Dozer 40 85
Dump Truck 40 84
Excavator 40 85
Flatbed Truck 40 84
Man Lift (Forklift) 20 85
Front‐End Loader 40 80
Generator 50 82
Generator (<25KVA, VMS signs) 50 70
Grader 40 85
Jackhammer 20 85
Pavement Scarifier 20 85
Paver 50 85
Pickup Truck 40 55
Pneumatic Tools 50 85
Pump 50 77
Rock Drill 20 85
Roller 20 85
Scraper 40 85
Tractor 40 84
Welder/Torch 40 73
Source: Table 9.1, FHWA Highway Construction Noise Handbook (FHWA 2006).
Note: The noise levels reported in this table are rounded to the nearest whole number.
1 Usage factor is the percentage of time during a construction noise operation that a piece of construction equipment is operating at
full power.
2 Maximum noise levels were developed based on Specification 721.560 from the CA/T program to be consistent with the City of
Boston, Massachusetts, Noise Code for the “Big Dig” project.
CA/T = Central Artery/Tunnel
FHWA = Federal Highway Administration
ft = foot/feet
Lmax = maximum instantaneous noise level
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Table I lists the anticipated construction equipment for each construction phase based on the
CalEEMod (Version 2020.4.0) results contained in Attachment B of the Air Quality Impact Analysis
Memorandum for the LEGOLAND California Project 2025 (LSA 2023). Table I shows the combined
noise level at 50 ft from all of the equipment in each phase and the Leq noise level for each piece of
equipment at 50 ft based on the quantity, reference instantaneous maximum (Lmax) noise level at 50
ft, and the acoustical usage factor. As shown in Table I, construction noise levels would reach up to
87.1 Leq at a distance of 50 ft.
Table I: Summary of Construction Phase, Equipment, and Noise Levels
Construction
Phase
Construction
Equipment Quantity
Reference
Noise Level
at 50 ft
(dBA Lmax)
Acoustical
Usage
Factor1
(%)
Noise Level
at 50 ft
(dBA Leq)
Combined
Noise
Level
at 50 ft
(dBA Leq)
Demolition
Front‐End Loader 3 80 40 80.8
86.5 Dozer 1 85 40 81.0
Concrete Saw 1 90 20 83.0
Site Preparation
Graders 1 85 40 81.0
84.7 Scraper 1 85 40 81.0
Front‐End Loader 1 80 40 76.0
Grading
Graders 1 85 40 81.0
85.2 Dozers 1 85 40 81.0
Front‐End Loader 2 80 40 79.0
Building Construction
Cranes 1 85 16 77.0
85.1
Forklifts 2 85 20 81.0
Generator 1 82 50 79.0
Front‐End Loader 1 80 40 76.0
Welders 3 73 40 73.8
Paving
Front‐End Loader 1 80 40 76.0
87.1
Pavers 1 85 50 82.0
Pavement Scarafier 1 85 20 78.0
Rollers 2 85 20 81.0
Concrete Mixer Truck 1 85 40 81.0
Architectural Coating Air Compressors 1 80 40 76.0 76.0
Source: Compiled by LSA (2023).
1 The acoustical usage factor is the percentage of time during a construction noise operation that a piece of construction equipment
operates at full power.
dBA = A‐weighted decibels
ft = foot/feet
Leq = equivalent continuous sound level
Lmax = maximum instantaneous noise level
The closest residence and resort hotel property lines are approximately 3,065 ft and 925 ft,
respectively, from the center of the project site and may be subject to short‐term construction noise
reaching 51.4 and 61.8 dBA Leq, generated by construction activities in the project area. Construction
noise is temporary and would stop once project construction is completed. Compliance with the
City’s hours of construction pursuant to Section 8.48.010 of the City’s Municipal Code listed below
would ensure construction‐related noise would not be generated during the more sensitive
nighttime hours. Furthermore, construction‐related noise levels would be below the FTA noise level
7/31/23 «P:\20231502‐Legoland Mars Attraction\Product\Noise\Noise Memo.docx» 12
standards of 80 and 85 dBA Leq for residential and commercial uses, respectively. Therefore, no
construction noise impacts would occur, and no noise reduction measures are required.
The construction contractor shall limit construction activities to between the hours of 7:00 a.m.
and 6:00 p.m. on weekdays and between the hours of 8:00 a.m. and 6:00 p.m. on Saturdays
pursuant to Section 8.48.010 of the City’s Municipal Code (City of Carlsbad 2023). Construction
is prohibited outside these hours and on Sundays and federal holidays.
Short‐Term Construction Vibration Impacts
This construction vibration impact analysis discusses the level of human annoyance using vibration
levels in RMS (VdB) and assesses the potential for building damage using vibration levels in PPV
(in/sec). Vibration levels calculated in RMS velocity are best for characterizing human response to
building vibration, whereas vibration levels in PPV are best for characterizing damage potential.
Table J shows the reference vibration levels at a distance of 25 ft for each type of standard
construction equipment from the FTA Manual (2018). Project construction is expected to require the
use of large bulldozers and loaded trucks, which would generate ground‐borne vibration levels of up
to 87 VdB (0.089 PPV [in/sec]) and 86 VdB (0.076 PPV [in/sec]), respectively, when measured at
25 ft.
Table J: Vibration Source Amplitudes for Construction Equipment
Equipment Reference PPV/LV at 25 ft
PPV (in/sec) LV (VdB)1
Pile Driver (Impact), Typical 0.644 104
Pile Driver (Sonic), Typical 0.170 93
Vibratory Roller 0.210 94
Hoe Ram 0.089 87
Large Bulldozer2 0.089 87
Caisson Drilling 0.089 87
Loaded Trucks2 0.076 86
Jackhammer 0.035 79
Small Bulldozer 0.003 58
Source: Transit Noise and Vibration Impact Assessment Manual (FTA 2018).
1 RMS vibration velocity in decibels (VdB) is 1 µin/sec.
2 The equipment shown in bold is expected to be used on site.
µin/sec = microinches per second
ft = foot/feet
FTA = Federal Transit Administration
in/sec = inches per second
LV = vibration velocity in decibels
PPV = peak particle velocity
RMS = root‐mean‐square
VdB = vibration velocity decibels
The greatest vibration levels are anticipated to occur during the site preparation and grading phases.
All other phases are expected to result in lower vibration levels. The distance to the nearest
buildings for vibration impact analysis is measured between the nearest off‐site buildings and the
project boundary (assuming the construction equipment would be used at or near the project
boundary) because vibration impacts normally occur within the buildings.
7/31/23 «P:\20231502‐Legoland Mars Attraction\Product\Noise\Noise Memo.docx» 13
The formula for vibration transmission is provided below:
LvdB (D) = LvdB (25 ft) ‐ 30 Log (D/25)
PPVequip = PPVref x (25/D)1.5
Table K lists the projected vibration levels from various construction equipment expected to be used
on the project site in the active construction area to the nearest buildings in the project vicinity. As
shown in Table K, the closest building to the west is approximately 565 ft from the center of the
project and would experience a vibration level of up to 46 VdB. This vibration level would not have
the potential to result in community annoyance because vibration levels would not exceed the FTA
community annoyance threshold of 84 VdB for offices and buildings not as sensitive to vibration.
Table K: Potential Construction Vibration Annoyance
Land Use Direction Equipment/
Activity
Reference
Vibration Level
(VdB) at 25 ft
Distance to
Structure (ft)1
Vibration Level
(VdB)
Business Park West Large bulldozers 87 565 46
Loaded trucks 86 565 45
Source: Compiled by LSA (2023).
Note: The FTA threshold perception is 65 VdB.
1 Distance from the center of the project site to the building structure.
ft = foot/feet
FTA = Federal Transit Administration
VdB = vibration velocity decibels
Similarly, Table L lists the projected vibration levels from various construction equipment expected
to be used on the project site at the project construction boundary to the nearest off‐site building in
the project vicinity. As shown in Table L, the closest business park building west of the project site is
approximately 305 ft from the project construction boundary and would experience a vibration level
of up to 0.002 PPV (in/sec). These vibration levels would not result in building damage because
business park buildings would be constructed equivalent to or better than non‐engineered timber
and masonry and vibration levels would not exceed the FTA vibration damage threshold of 0.20 PPV
(in/sec). Therefore, no construction vibration impacts during project construction would occur. No
vibration reduction measures are required.
Table L: Potential Construction Vibration Damage
Land Use Direction Equipment/
Activity
Reference
Vibration Level
at 25 ft
Distance to
Structure (ft)1
Vibration Level
PPV (in/sec) PPV (in/sec)
Business Park West Large bulldozers 0.089 305 0.002
Loaded trucks 0.076 305 0.002
Source: Compiled by LSA (2023).
Note: The FTA‐recommended building damage threshold is 0.20 PPV [in/sec]) at the receiving non‐engineered timber and masonry
building.
1 Distance from the project construction boundary to the building structure.
ft = foot/feet
FTA = Federal Transit Administration
in/sec = inches per second
PPV = peak particle velocity
VdB = vibration velocity decibels
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Long‐Term Traffic Noise Impacts
Based on the LEGOLAND California Project 2025 – California Environmental Quality Act (CEQA) Infill
Development Categorical Exemption (Transportation) [C2 Consulting Collective 2023], the trip
generation of the project is not expected to change because there is no expansion of the existing
LEGOLAND theme park footprint and there is no measurable change to the land use type. Given the
above, traffic noise along roadways leading to the project site would remain the same under with
project condition. Therefore, no traffic noise impacts from project‐related traffic on off‐site sensitive
receptors would occur. No noise reduction measures are required.
Long‐Term Stationary Noise Impacts
As discussed above, the proposed project would replace the existing “Driving School” and “Junior
Driving School” attractions. Based on the project plans, the proposed project would include three
rooftop heating, ventilation and air conditioning (HVAC) units, seven split air conditioning systems,
and 19 outdoor speakers that would generate noise. It is expected that noise generated from the
proposed project would be similar to the existing “Driving School” and “Junior Driving School”
attractions as well as other attractions located within the theme park, particularly the existing
“Emmet’s Flying Adventure – Masters of Flight” attraction located immediately south of the
proposed project, which is also an indoor ride. Noise‐sensitive land uses closest to the project site
include residences and a resort hotel to the south, which are located approximately 3,065 ft and
925 ft, respectively, from the center of the project. At these distances and a reference distance of 50
ft, noise would be attenuated by 35.7 dBA and 25.3 dBA, respectively. Based on the above, noise
generated from the proposed project is not expected to exceed the City’s daytime performance
standards of 55 dBA Leq and 75 dBA Lmax for non‐transportation sources (stationary sources). The
City’s nighttime performance standards for stationary sources would not be exceeded because the
proposed project and the theme park would not operate during nighttime hours. Also, traffic noise
on roadways closest to the nearest residences and the resort hotel south of the project site would
be the primary noise source, and noise generated by the proposed project would not contribute to
any perceptible increase in ambient noise level. Therefore, noise impacts from project operations
would not occur. No noise reduction measures are required.
Long‐Term Vibration Impacts
The proposed project would not generate vibration. In addition, vibration levels generated from
project‐related traffic on roadways leading to the project site are unusual for on‐road vehicles
because the rubber tires and suspension systems of on‐road vehicles provide vibration isolation.
Vibration generated from operations of the project would not exceed the FTA’s vibration perception
threshold of 65 VdB. Therefore, vibration impacts from project‐related operations would be less
than significant. No mitigation measures are required.
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REGULATORY COMPLIANCE MEASURES
The following measure would ensure than construction noise be only generated during allowable
times:
The construction contractor shall limit construction activities to between the hours of 7:00 a.m.
and 6:00 p.m. on weekdays and between the hours of 8:00 a.m. and 6:00 p.m. on Saturdays
pursuant to Section 8.48.010 of the City’s Municipal Code (City of Carlsbad 2023). Construction
is prohibited outside these hours and on Sundays and federal holidays.
Attachments: A: References
B: Figures
A‐1
NOISE AND VIBRATION IMPACT ANALYSIS
JULY 2023
LEGOLAND CALIFORNIA PROJECT 2025
CARLSBAD, CALIFORNIA
P:\20231502‐Legoland Mars Attraction\Product\Noise\Noise Memo.docx (07/31/23)
ATTACHMENT A
REFERENCES
C2 Consulting Collective. 2023. LEGOLAND California Project 2025 – California Environmental Quality
Act (CEQA) Infill Development Categorical Exemption (Transportation). June 26.
City of Carlsbad. 2015. Carlsbad General Plan, Noise Element. September.
_____. 2023. Municipal Code. May.
Federal Highway Administration (FHWA). 2006. Highway Construction Noise Handbook. Roadway
Construction Noise Model, FHWA‐HEP‐06‐015. DOT‐VNTSC‐FHWA‐06‐02. NTIS No. PB2006‐
109012. August.
Federal Transit Administration (FTA). 2018. Transit Noise and Vibration Impact Assessment Manual.
FTA Report No. 0123. September. Website: https://www.transit.dot.gov/sites/fta.dot.gov/
files/docs/research‐innovation/118131/transit‐noise‐and‐vibration‐impact‐assessment‐
manual‐fta‐report‐no‐0123_0.pdf (accessed July 2023).
Harris, Cyril M., editor. 1991. Handbook of Acoustical Measurements and Noise Control. Third
Edition.
LSA Associates, Inc. (LSA). 2023. Air Quality Impact Analysis Memorandum for the LEGOLAND
California Project 2025. July 31.
San Diego County Airport Land Use Commission (SDCALUC). 2011. McClellan‐Palomar Airport Land
Use Compatibility Plan. December 1. Website: https://www.lee‐associates.com/elee/
sandiego/LeeLandTeam/Ponto/McClellan‐Palomar_ALUCP_20111.pdf (accessed July 2023).
NOISE AND VIBRATION IMPACT ANALYSIS
JULY 2023
LEGOLAND CALIFORNIA PROJECT 2025
CARLSBAD, CALIFORNIA
P:\20231502‐Legoland Mars Attraction\Product\Noise\Noise Memo.docx «07/31/23»
ATTACHMENT B
FIGURES
Figure 1: Regional and Project Location
Figure 2: Site Plan
S21
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Farr
SOURCE: ESRI StreetMap, 2023
I:\20231502\G\Location.ai (7/14/2023)
FIGURE 1
LEGOLAND California Project 2025
CA78
Encinitas
Oceanside
Carlsbad
Vista
5
Project Vicinity
0 1000 2000
FEET Project Location
Project Location
727$/6,7($5($6)
SOURCE: HHCP
FEET
80400
FIGURE 2
I:\20231502\G\Site_Plan.ai (7/14/2023)
LEGOLAND California Project 2025
Site Plan