iv. environmental impact analysis i. noise · 110 rock band jet fly-over at 1000 feet 100 gas lawn...

County of Los Angeles LACMA Building for the Permanent Collection SCH No. 2016081014 October 2017

Page IV.I-1

IV. Environmental Impact Analysis I. Noise

1. Introduction

This section of the Draft EIR analyzes the potential noise and vibration impacts associated with the Project. Specifically, the analysis describes the existing noise environment in the Project vicinity, estimates future noise and vibration levels at surrounding sensitive land uses resulting from construction and operation of the Project, identifies the potential for significant impacts, and provides mitigation measures to address significant impacts. In addition, an analysis of potential cumulative noise and vibration impacts is also provided. Noise calculation worksheets are included in Appendix K of this Draft EIR.

2. Environmental Setting

a. Noise and Vibration Fundamentals

(1) Noise

(a) Fundamentals of Sound and Environmental Noise

Noise is commonly defined as sound that is undesirable because it interferes with speech communication and hearing, causes sleep disturbance, or is otherwise annoying (unwanted sound). The decibel (dB) is a conventional unit for measuring the amplitude of sound as it accounts for the large variations in sound pressure amplitude and reflects the way people perceive changes in sound amplitude.1 Human hearing is not equally sensitive to sound at all frequencies. Therefore, to approximate this human frequency-dependent response, the A-weighted filtering system is used to adjust measured sound levels (dBA). The term “A-weighted” refers to filtering the noise signal in a manner that corresponds to the way the human ear perceives sound. Examples of various sound levels in different environments are shown in Table IV.I-1 on page IV.I-2.

1 All sound levels measured in decibel (dB), as identified in the noise calculation worksheets included in

Appendix K to this Draft EIR and in this section of the Draft EIR, are relative to 2x10-5 N/m2.

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Table IV.I-1 Typical Noise Levels

Common Outdoor Activities Noise Levels

(dBA) Common Indoor Activities

110 Rock Band Jet Fly-Over at 1000 feet

100 Gas Lawn Mower at 3 feet

90 Diesel Truck at 50 feet at 50 mph Food Blender at 3 feet

80 Garbage Disposal at 3 feet Noisy Urban Area, Daytime

Gas Lawn Mower at 100 feet 70 Vacuum Cleaner at 10 feet Commercial Area Normal Speech at 3 feet

Heavy Traffic at 300 feet 60 Large Business Office

Quiet Urban Daytime 50 Dishwasher Next Room

Quiet Urban Nighttime 40 Theater, Large Conference Room (background) Quiet Suburban Nighttime

30 Library Quiet Rural Nighttime Bedroom at Night, Concert Hall (background)

20 Broadcast/Recording Studio 10 0

Source: Caltrans, Technical Noise Supplement (TeNS), Table 2-5, 2013.

People commonly judge the relative magnitude of sound sensation using subjective terms such as “loudness” or “noisiness.” A change in sound level of 3 dB is considered “just perceptible,” a change in sound level of 5 dB is considered “clearly noticeable,” and a change (increase) of 10 dB is typically recognized as “twice as loud.”2

(b) Outdoor Sound Propagation

In an outdoor environment, sound energy attenuates through the air as a function of distance. Such attenuation is called “distance loss” or “geometric spreading,” and is based on the type of source configuration (i.e., a point source, or a line source). The rate of sound attenuation for a point source, such as a piece of mechanical or electrical equipment 2 Bies & Hansen, Engineering Noise Control, 1988, Table 2.1.

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(e.g., air conditioner or bull dozer), is 6 dBA per doubling of distance from the noise source to the receptor at acoustically “hard” sites and 7.5 dBA at acoustically “soft” sites.3 For example, an outdoor condenser fan that generates a sound level of 60 dBA at a distance of 50 feet from a point source at an acoustically hard site would attenuate to 54 dBA at a distance of 100 feet from the point source and attenuate to 48 dBA at 200 feet from the point source. The rate of sound attenuation for a line source, such as a constant flow of traffic on a roadway, is 3 dBA and 4.5 dBA per doubling of distance from the noise source to the receptor for hard and soft sites, respectively.4

In addition, structures (e.g., buildings and solid walls) and natural topography (e.g., hills and berms) that obstruct the line of sight between a noise source and a receptor further reduce the noise level if the receptor is located within the “shadow” of the obstruction, such as behind a sound wall. This type of sound attenuation is known as “barrier insertion loss.” If a receptor is located behind the wall but still has a view of the source (i.e., the line of sight is not fully blocked), some barrier insertion loss would still occur, but to a lesser extent. Additionally, a receptor located on the same side of the wall as a noise source may actually experience an increase in the perceived noise level as the wall reflects noise back to the receptor, thereby compounding the noise. Noise barriers can provide noise level reductions ranging from approximately 5 dBA (where the barrier just breaks the line of sight between the source and receiver) to an upper range of 20 dBA with a more substantial barrier.5 Additionally, structures with closed windows can further attenuate exterior noise by a minimum of 25 dBA to 30 dBA.6

(c) Environmental Noise Descriptors

Several rating scales have been developed to analyze the adverse effect of community noise on people. Since environmental noise fluctuates over time, these scales consider that the effect of noise is dependent upon the total acoustical energy content, as well as the time and duration of occurrence. The most frequently used noise descriptors are summarized below.

Equivalent Sound Level (Leq). Leq is a measurement of the acoustic energy content of noise averaged over a specified time period. Thus, the Leq of a time-varying sound and that of a steady sound are the same if they deliver the same amount of energy to the receptor’s ear during exposure. Leq for 1-hour periods, during the daytime or nighttime

3 Caltrans, Technical Noise Supplement (TeNS), 2009, Chapter 2.1.4.2. 4 Ibid. 5 Ibid. 6 FHWA, Highway Traffic Noise Analysis and Abatement Policy and Guidance, 1995.

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hours, and 24-hour periods are commonly used in environmental assessments. For evaluating community impacts, this rating scale does not vary, regardless of whether the noise occurs during day or night.

Maximum Sound Level (Lmax). Lmax represents the maximum sound level measured during a measurement period.

Statistical Sound Level (Ln). Ln is a statistical description of the sound level that is exceeded over some fraction of a given period of time. For example, the L50 noise level represents the noise level that is exceeded 50 percent of the time. Half the time the noise level exceeds this level and half the time the noise level is less than this level. This level is also representative of the level that is exceeded 30 minutes in an hour. Similarly, the L8 and L25 represent the noise levels that are exceeded 8 and 25 percent of the time, respectively, or for 5 and 15 minutes during a 1-hour period, respectively. The County of Los Angeles noise limits are provided in terms of statistical sound levels.

Community Noise Equivalent Level (CNEL). CNEL is the time average of all A-weighted sound levels for a 24-hour period with a 10 dBA adjustment (upward) added to the sound levels that occur between the hours of 10:00 P.M. and 7:00 A.M. (nighttime), and a 5 dBA adjustment (upward) added to the sound levels which occur between the hours of 7:00 P.M. and 10:00 P.M. (evening). These penalties attempt to account for increased human sensitivity to noise during the nighttime and evening periods, particularly where sleep is the most probable activity. CNEL has been adopted by the State of California to define the community noise environment for development of the community noise element of a General Plan and is also used by the City for land use planning and to describe noise impacts in the L.A. CEQA Thresholds Guide.7

(2) Ground-Borne Vibration

Vibration is commonly defined as an oscillatory motion through a solid medium in which the motion’s amplitude can be described in terms of displacement, velocity, or acceleration. The peak particle velocity (PPV) or the root-mean square (RMS) velocity is usually used to describe vibration amplitudes. PPV is defined as the maximum instantaneous peak of the vibration signal and is typically used for evaluating potential building damage.8 The RMS velocity is defined as the square-root of the average of the squared amplitude of the vibration signal and is typically more suitable for evaluating

7 State of California, General Plan Guidelines, 2003. 8 Vibration levels are described in the noise calculation worksheets included in Appendix K to this Draft EIR

and in this section of the Draft EIR in terms peak particle velocity level in the unit of inches per second.

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human response to ground-borne vibration.9 The RMS vibration velocity level can be presented in inch per second or in VdB (a decibel unit referenced to 1 micro-inch per second).10 Ground-borne vibration generated by man-made activities (e.g., road traffic, construction operations) typically weakens with greater horizontal distance away from the source of the vibration.

b. Regulatory Framework

Various government agencies have established noise regulations and policies to protect citizens from potential hearing damage and other adverse effects associated with noise and ground-borne vibration. An overview of the State, County and City regulations and policies that are relevant to construction and operation of the Project is provided below.

While the Project Site is located within the City of Los Angeles, LACMA is operated by Museum Associates under the authority of the County of Los Angeles. Notwithstanding, noise sensitive receptors adjacent to the Project Site are within the City of Los Angeles. Thus, the more restrictive of the applicable policies and regulations from the County of Los Angeles and the City of Los Angeles are used to assess potential noise impacts from the Project.

(1) Applicable State Noise Standards

The State of California has adopted noise compatibility guidelines for general land use planning. The types of land uses addressed by the State standards and the acceptable noise categories for each land use are included in the State of California General Plan Guidelines, which is published and updated by the Governor’s Office of Planning and Research. The level of acceptability of the noise environment is dependent upon the activity associated with the particular land use. Table IV.I-2 on page IV.I-6 provides the exterior noise standard associated with various land uses, as described by the State of California land use compatibility for community noise environment. According to the State, an exterior noise environment up to 65 dBA CNEL is “normally acceptable” for multi-family residential uses, without special noise insulation requirements. In addition,

9 Federal Transit Administration (FTA), “Transit Noise and Vibration Impact Assessment,” Section 7.1.2,

May 2006. 10 VdB (velocity level in decibel) = 20 x Log (V / Vref), where V is the RMS velocity amplitude in micro-inch

per second and Vref is the reference velocity amplitude of 1x10-6 inch per second (1 micro-inch per second). All vibration levels described in decibel (VdB) in the noise calculation worksheets included in Appendix K to this Draft EIR and in this section of the Draft EIR are RMS and referenced to 1 micro-inch per second.

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Table IV.I-2 Land Use Compatibility for Exterior Community Noise Exposure

Community Exposure Level, CNEL (dBA)

Land Use Normally

Acceptable Conditionally Acceptable

Normally Unacceptable

Clearly Unacceptable

Residential: Low-Density Single-Family, Duplex, Mobile Homes

50 to 60 55 to 70 70 to 75 Above 75

Residential: Multi-Family 50 to 65 60 to 70 70 to 75 Above 75

Transient Lodging: Motels, Hotels 50 to 65 60 to 70 70 to 80 Above 80

Schools, Libraries, Churches, Hospitals, Nursing Homes

50 to 70 60 to 70 70 to 80 Above 80

Auditoriums, Concert Halls, Amphitheaters

— 50 to 70 — Above 65

Sports Arena, Outdoor Spectator Sports — 50 to 75 — Above 70

Playgrounds, Neighborhood Parks 50 to 70 — 67 to 75 Above 72

Golf Courses, Riding Stables, Water Recreation, Cemeteries

50 to 75 — 70 to 80 Above 80

Office Buildings, Business Commercial and Professional

50 to 70 67 to 77.5 Above 75 —

Industrial, Manufacturing, Utilities, Agriculture

50 to 75 70 to 80 Above 75 —

Normally Acceptable: Specified land use is satisfactory, based upon the assumption that any buildings involved are of normal conventional construction without any special noise insulation requirements.

Conditionally Acceptable: New construction or development should be undertaken only after a detailed analysis of the noise reduction requirements is made and needed noise insulation features included in the design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning will normally suffice.

Normally Unacceptable: New construction or development should generally be discouraged. If new construction or development does proceed, a detailed analysis of the noise reduction requirements must be made and needed noise insulation features included in the design.

Clearly Unacceptable: New construction or development should generally not be undertaken.

Source: Office of Planning and Research, State of California General Plan Guidelines, October 2003.

noise levels up to 70 dBA CNEL are “conditionally acceptable” with special noise insulation requirements, while noise levels at 75 dBA CNEL and above are “clearly unacceptable” for residential and hotel uses.11

11 State of California, Governor’s Office of Planning and Research, General Plan Guidelines, October 2003,

p. 250.

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(2) County of Los Angeles Noise Standards

(a) Los Angeles County General Plan

As discussed in more detail in Section H, Land Use and Planning, of the EIR, the County Board of Supervisors (Board) adopted the Los Angeles County General Plan 2035 (County General Plan) on October 6, 2015. The County General Plan directs future growth and development in the County’s unincorporated areas and establishes goals, policies, and objectives that pertain to the entire County. The County General Plan includes a Noise Element that addresses land use compatibility as it relates to noise levels, noise abatement to achieve acceptable noise levels as defined by the County’s Exterior Noise Standards, and cumulative noise impacts. The noise guidelines used by the County are based on the community noise compatibility guidelines established by the State of California, described above. Specific regulations that implement these guidelines are set forth in the Los Angeles County Code (County Code), discussed below. Relevant policies in the Noise Element focus on minimizing transportation-related noise and promoting public awareness of noise effects.

The County General Plan policy consistency analysis provided in Section H, Land Use, of this Draft EIR, indicates the Project is consistent with applicable County General Plan polices related to noise.

(b) County of Los Angeles Noise Control Ordinance

The Noise Control Ordinance of the County of Los Angeles (County Noise Ordinance Section 12.08.010, et seq., of the County Code) identifies exterior noise standards for any source of sound, as well as specific exemptions for exterior noise sources. The primary components of the County Noise Ordinance are described below.

The County Noise Ordinance provides maximum exterior noise level standards for four general noise zones and establishes maximum exterior noise levels for each zone. These noise zones are:

1. Noise-Sensitive Areas—Noise-sensitive zones are designated by the County Health Officer.

2. Residential Properties—This category includes all types of residential developments and properties subject to residential zoning.

3. Commercial Properties—This category includes all types of commercial developments and also includes properties subject to commercial zoning classifications.

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4. Industrial Properties—This category includes all properties developed with manufacturing uses and also includes properties subject to industrial zoning.

With regard to maximum exterior noise levels, for each of these zones, the County Noise Ordinance states that exterior operational noise levels caused by Project-related on-site fixed sources (i.e., point noise sources) shall not exceed the levels identified in Table IV.I-3 on page IV.I-9, or the ambient noise level, whichever is greater, when the ambient noise level is determined without the noise source operating.12 These standards are based on the duration of the noise. Thus, the louder the noise, the shorter the duration that such noise can last. To define these specific durations of noise, the noise metrics used include L50, L25, L8.3, L1.7, and L0 (L0 represents the maximum noise level, which can also be described as Lmax). As described above, these metrics are based upon a 1-hour timeframe which indicates exceedances of 50, 25, 8.3, and 1.7 percent of the time, plus the maximum sound level during that time period.

The County Noise Ordinance also identifies specific restrictions regarding construction noise. Pursuant to the County Noise Ordinance, the operation of equipment used in construction, drilling, repair, alteration or demolition work is prohibited between the hours of 7:00 P.M. and 7:00 A.M. Monday through Friday, before 8:00 A.M. or after 6:00 P.M. on Saturday, and anytime on Sundays or legal holidays if such noise would create a noise disturbance across a residential or commercial real-property line.13 The County Noise Ordinance further states the contractor must conduct construction activities in such a manner that the maximum noise levels at the affected buildings will not exceed those listed in Table IV.I-4 on page IV.I-10. All mobile and stationary internal-combustion-powered equipment and machinery are also required to be equipped with suitable exhaust and air-intake silencers in proper working order.

The County Code also provides exemptions from the construction standards set forth under Chapter 12.12 of the County Code. Specifically, Section 12.12.050 of the County Code provides an exemption for construction work performed with the County Engineer’s permission if the County Engineer can make the finding that: (1) the work proposed to be done is effected with a public interest; (2) that hardship, injustice or unreasonable delay would result from the interruption of construction activities; or (3) that the building or structure involved is devoted or intended to be devoted to a use immediately 12 Ambient noise level is the existing background noise level at the time of measurement or prediction. 13 County of Los Angeles Ordinance No. 11743, codified in Los Angeles County Code Section 12.08.440.

Noise disturbance is defined in Los Angeles County Code Section 12.08.230 as “an alleged intrusive noise which violates an applicable noise standard as set forth in this chapter.” The County Health Officer has the authority to define and determine the extent of a noise disturbance on a case-by-case basis.

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Table IV.I-3 County of Los Angeles Exterior Noise Standards

Noise Zone

Designated Noise Zone Land Use

(Receptor Property) Time Interval

Exterior Noise Levels,a

dBA

I Noise-Sensitive Areab Anytime 45

II Residential Properties 10:00 P.M. to 7:00 A.M. 7:00 A.M. to 10:00 P.M.

45 50

III Commercial Properties 10:00 P.M. to 7:00 A.M. 7:00 A.M. to 10:00 P.M.

55 60

IV Industrial Properties Anytime 70

a This Table is used by the County to develop noise standards based on the duration of the noise

source. These standards are described below. Standard No. 1 shall be the exterior noise level which may not be exceeded for a cumulative period

of more than 30 minutes in any hour. Standard No. 1 shall be the applicable noise level; or, if the ambient L50 exceeds the forgoing level, then the ambient L50 becomes the exterior noise level for Standard No. 1.

Standard No. 2 shall be the exterior noise level which may not be exceeded for a cumulative period of more than 15 minutes in any hour. Standard No. 2 shall be the applicable noise level from Standard 1 plus 5 dBA; or, if the ambient L25 exceeds the forgoing level, then the ambient L25 becomes the exterior noise level for Standard No. 2

Standard No. 3 shall be the exterior noise level which may not be exceeded for a cumulative period of more than five minutes in any hour. Standard No. 3 shall be the applicable noise level from Standard 1 plus 10 dBA; or, if the ambient LB8.3 exceeds the forgoing level, then the ambient L8.3 becomes the exterior noise level for Standard No. 3.

Standard No. 4 shall be the exterior noise level which may not be exceeded for a cumulative period of more than one minute in any hour. Standard No. 4 shall be the applicable noise level from Standard 1 plus 15 dBA, or, if the ambient L1.7 exceeds the forgoing level, then the ambient L1.7 becomes the exterior noise level for Standard No. 4.

Standard No. 5 shall be the exterior noise level which may not be exceeded for any period of time. Standard No. 5 shall be the applicable noise level from Standard 1 plus 20 dBA; or, if the ambient L0 exceeds the forgoing level, then the ambient L0 becomes the exterior noise level for Standard No. 5.

b Not defined in the County Noise ordinance. To be designated by the County Health Officer.

Source: County of Los Angeles Ordinance No. 11743, §12.08.390

incident to public defense. In addition, Section 12.12.060 of the County Code exempts construction work by public utilities that are subject to the jurisdiction of the Public Utilities Commission where such work is necessary for the preservation of life or property, and where such necessity makes it necessary to construct, repair or excavate during prohibited hours.

Section 12.08.560 of the County Noise Ordinance establishes maximum vibration thresholds during construction activities. Specifically, the operation of any device that

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Table IV.I-4 County of Los Angeles Construction Noise Limits

Noise Limits, dBA (Leq)

Single-Family Residential

Multi-Family Residential Commerciala

Residential Structures

Mobile Equipment: Maximum noise levels for nonscheduled, intermittent, short-term operation (less than 10 days) of mobile equipment

Daily, except Sundays and legal holidays, 7:00 A.M. to 8:00 P.M.

75 80 85

Daily, 8:00 P.M. to 7:00 A.M. and all day Sunday and legal holidays

60 64 70

Stationary Equipment: Maximum noise levels for repetitively scheduled and relatively long-term operation (periods of 10 days or more) of stationary equipment

Daily, except Sundays and legal holidays, 7:00 A.M. to 8:00 P.M.

60 65 70

Daily, 8:00 P.M. to 7:00 A.M. and all day Sunday and legal holidays

50 55 60

All Structures

Business Structures

Mobile Equipment: Maximum noise levels for nonscheduled, intermittent, short-term operation of mobile equipment

Daily, including Sundays and legal holidays, all hours 85

a Refers to residential structures within a commercial area. This standard does not apply to commercial

structures.

Source: County of Los Angeles Ordinance No. 11743, §12.08.390

creates vibration above the vibration perception threshold (motion velocity of 0.01 inch per second over the range of 1 to 100 hertz) of an individual at or beyond the property boundary of the source if on private property, or at 150 feet from the source if on a public space or public right-of-way is prohibited.

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(3) City of Los Angeles Noise Regulations

Chapter XI, Noise Regulation, of the LAMC (referred to herein as the Noise Regulation) establishes acceptable ambient sound levels to regulate intrusive noises (e.g., stationary mechanical equipment and vehicles other than those traveling on public streets) within specific land use zones and provides procedures and criteria for the measurement of the sound level of noise sources. These procedures recognize and account for differences in the perceived level of different types of noise and/or noise sources. In accordance with the Noise Regulation, a noise level increase from certain regulated noise sources of 5 dBA over the existing or presumed ambient noise level at an adjacent property line is considered a violation of the Noise Regulation. The 5-dBA increase above ambient is applicable to City-regulated noise sources (e.g., mechanical equipment) and it is applicable any time of the day.14

The Noise Regulation states that the baseline ambient noise shall be the actual measured ambient noise level or the City’s presumed ambient noise level, whichever is greater. The actual ambient noise level is the measured noise level averaged over a period of at least 15 minutes, Leq (15-minute). The Noise Regulation indicates that in cases where the actual measured ambient conditions are not known, the City’s presumed daytime (7:00 A.M. to 10:00 P.M.) and nighttime (10:00 P.M. to 7:00 A.M.) ambient noise levels defined in Section 111.03 of the LAMC should be used. The City’s presumed ambient noise levels for specific land use zones are set forth in the LAMC Section 111.03 and are provided in Table IV.I-5 on page IV.I-12. As indicated therein, for residential-zoned areas, the presumed ambient noise level is 50 dBA during the daytime and 40 dBA during the nighttime. As further discussed below, the measured existing ambient noise levels in the vicinity of the Project Site exceed these presumed ambient noise levels.

To account for people’s increased tolerance for short-duration noise events, the Noise Regulation provides a 5 dBA allowance for noise sources occurring more than 5 minutes but less than 15 minutes in any 1-hour period (for a total of 10 dBA above the ambient), and an additional 5 dBA allowance (total of 15 dBA above the ambient) for noise sources occurring 5 minutes or less in any 1-hour period. These additional allowances for short-duration noise sources are applicable to noise sources occurring between the hours of 7:00 A.M. and 10:00 P.M. (daytime hours). Furthermore, the Noise Regulation provides a reduction of 5 dBA for steady high-pitched noise or repeated impulsive noises.15, 16

14 Los Angeles Municipal Code, Chapter XI, Section 112.02. 15 Los Angeles Municipal Code, Chapter XI, Article I, Section 111.02-(b).

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In addition, the City’s Noise Regulation Section 112.05 sets a maximum noise level from construction equipment (powered equipment or powered hand tools) operating between the hours of 7:00 A.M. and 10:00 P.M., in any residential zone of the City or within 500 feet thereof, of 75 dBA, measured at a distance of 50 feet from the source, unless compliance with this limitation is technically infeasible.17 Section 41.40 of the LAMC prohibits construction noise that disturbs persons occupying sleeping quarters in any dwelling, hotel, or apartment or other place of residence between the hours of 9:00 P.M. and 7:00 A.M. Monday through Friday, before 8:00 A.M. and after 6:00 P.M. on Saturday, and at any time on Sunday or City-observed holidays. Construction hours may be extended with approval from the Executive Director of the Board of Police Commissioners.

(4) Ground-Borne Vibration

With respect to human annoyance, the County Noise Ordinance provides a vibration limit as to not exceed the vibration perception threshold. Specifically, Section 12.08.560 of the County Noise Ordinance specifies a vibration perception threshold of 0.01 inch per second, which is equal to 80 VdB.

The County and City do not have any adopted standards or limits relative to potential building damage from ground-borne vibration. Therefore, the available guidelines

16 Impulsive sound as defined in the LAMC Section 111.01-(e) is sound of short duration, usually less than

one second, with an abrupt onset and rapid decay. Examples of impulsive sound shall include, but are not limited to, explosion, musical base drum beats, or the discharge of firearms.

17 In accordance with the City of Los Angeles Noise Ordinances, “technically feasible” means that the established noise limitations can be complied with at a project site, with the use of mufflers, shields, sound barriers, and/or other noise reduction devices or techniques employed during the operation of equipment.

Table IV.I-5 City of Los Angeles Presumed Ambient Noise Levels

Zone

Daytime (7 A.M. to 10 P.M.)

dBA (Leq)

Nighttime (10 P.M. to 7 A.M.)

dBA (Leq)

Residential, School, Hospitals, Hotels 50 40

Commercial 60 55

Manufacturing (M1, MR1, and MR2) 60 55

Heavy Manufacturing (M2 and M3) 65 65

Source: City of Los Angeles Municipal Code, Section 111.03.

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from the FTA are utilized to assess impacts on potential building damage due to ground-borne vibration. The FTA has published a technical manual titled, “Transit Noise and Vibration Impacts Assessment,” which provides ground-borne vibration impact criteria with respect to building damage during construction activities.18 As discussed above, building vibration damage is measured in PPV described in the unit of inches per second. Table IV.I-6 on page IV.I-14 provides the FTA vibration criteria applicable to construction activities. According to FTA guidelines, a vibration criterion of 0.20 PPV should be considered as the significant impact level for non-engineered timber and masonry buildings. Structures or buildings constructed of reinforced concrete, steel, or timber, have a vibration damage criterion of 0.50 PPV pursuant to the FTA guidelines.

c. Existing Conditions

The Project Site is located in an urbanized area. The predominant source of noise in the vicinity of the Project Site is vehicular traffic on adjacent roadways, particularly along Wilshire Boulevard, Fairfax Avenue, 6th Street and 8th Street. Other ambient noise sources in the vicinity of the Project Site include trucks and buses; commercial activities; surface parking lot activities; construction noise from developing properties in the area; and other miscellaneous noise sources associated with typical urban activities.

(1) Noise-Sensitive Receptors

Some land uses are considered more sensitive to intrusive noise than others based on the types of activities typically involved at the receptor location. The L.A. CEQA Thresholds Guide states that residences, transient lodgings, schools, libraries, churches, hospitals, nursing homes, auditoriums, concert halls, amphitheaters, playgrounds, and parks are generally more sensitive to noise than are commercial and industrial land uses.19

Based on a review of the land uses in the Project area, a total of six off-site noise receptor locations were selected to represent noise sensitive uses in the Project area. As discussed below, noise measurements were conducted at these locations to establish baseline noise conditions in the Project area. The six noise measurement locations are shown on Figure IV.I-1 on page IV.I-15 and described in Table IV.I-7 on page IV.I-16.

18 FTA, “Transit Noise and Vibration Impact Assessment,” May 2006 19 City of Los Angeles, L.A. CEQA Thresholds Guide, p. I.1-3.

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(2) Ambient Noise Levels

To establish baseline noise conditions, existing ambient noise levels were monitored at the six representative off-site receptor locations in the vicinity of the Project Site. The baseline noise monitoring program was conducted on November 16–17, 2016 using a Quest Technologies Model 2900 and a Larson-Davis Model 870 Integrating/Logging Sound Level Meter.20 Two 15-minute measurements were conducted at five of the off-site receptor locations (receptors R1 through R5), one during the daytime hours and another during the nighttime hours. A 24-hour measurement was conducted at the off-site receptor location R6. A 15-minute measurement is a reasonable duration for sampling ambient noise levels where street traffic is the dominant source (typical of urban environments), as traffic noise generally does not vary significantly within an hour.

Table IV.I-8 on page IV.I-17 provides a summary of the ambient noise measurements taken at the five receptor locations. Based on field observations, the ambient noise at the measurement locations is dominated by local traffic, parking lots, and other typical urban noises. As indicated in Table IV.I-8, the existing daytime ambient noise levels at the six off-site locations ranged from 55.8 dBA (Leq) at Location R6 to 69.9 dBA (Leq) at Location R4, while the measured nighttime ambient noise levels ranged from 53.5 dBA (Leq) at Location R2 to 65.5 dBA (Leq) at Location R4. The existing ambient noise levels at off-site residential locations are above the City’s presumed daytime and nighttime ambient noise standards of 50 dBA (Leq) and 45 dBA (Leq) for residential uses, respectively, as presented above in Table IV.I-5 on page IV.I-12. Therefore, the measured existing

20 This sound meter meets and exceeds the minimum industry standard performance requirements for

“Type 2” standard instruments as defined in the American National Standard Institute (ANSI) S1.4. It also meets the requirement specified in Section 111.01(l) of the LAMC that instruments be “Type S2A” standard instruments or better. The sound meter was calibrated and operated according to the manufacturer’s written specifications.

Table IV.I-6 Federal Transit Administration Construction Vibration Impact Criteria for Building Damage

Building Category PPV (in/sec)

I. Reinforced-concrete, steel or timber (no plaster) 0.5

II. Engineered concrete and masonry (no plaster) 0.3

III. Non-engineered timber and masonry buildings 0.2

IV. Buildings extremely susceptible to vibration damage 0.12

Source: Federal Transit Administration, 2006.

A E SAcoustical Engineering Services

LACMA East EIR – Proposed Noise Monitoring Locations

2 Residential

LACMA EastProject Site

4 Residential

3 Residential

1 Residential

5 Residential6 Residential

Figure IV.I-1Noise Measurement Locations

Source: Acoustical Engineering Services, 2017.

John.Osako

Rectangle

jeremy.buck

Typewritten Text

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Table IV.I-7 Description of Noise Measurement Locations

Receptor Location Description

Approximate Distance from Measurement Location to Nearest

Project Site Boundarya

Nearest Noise-Sensitive Land

Use(s)

R1 Multi-family residences on the east side of Spaulding Avenue, adjacent to the Project Site to the south

20 feet Multi-Family Residential

R2 Multi-family residence on the east side of Stanley Avenue, east of the Project Site


R3 Multi-family residence on the east side of Curson Avenue, east of the Project Site


R4 Multi-family residence on the north side of West 6th Street, north of the Project Site


R5 Multi-family residence on the west side of Ogden Drive, adjacent to the Project Site (Ogden Lot) to the south


R6 Multi-family residence on the east side of Spaulding Avenue, adjacent to the Project Site to the south. Noise measurement was at the southeast corner of the Project Site (Spaulding Lot)


a Distances are estimated using Google Earth (Map data ©2016 Google).

Source: Acoustical Engineering Services (AES), 2017.

ambient noise levels are used as the baseline conditions for the purposes of determining Project impacts.

In addition to the ambient noise measurements in the vicinity of the Project Site, the existing traffic noise on local roadways in the surrounding areas were calculated to quantify the 24-hour CNEL noise levels using information provided by the Traffic Study.21 Twenty one (21) roadway segments were selected for the existing noise analysis, based on proximity to noise sensitive uses along the roadway segments and potential increases in traffic volume from the Project. Traffic noise levels were calculated using the Federal Highway Administration (FHWA) Traffic Noise Model (TNM) and traffic volume data from the Project’s Transportation Study.22 The TNM traffic noise prediction model calculates the

21 Gibson Transportation Consulting, Inc., Traffic Study for the Building for the Permanent Collection of the

Los Angeles County Museum of Art Project, March 2017, revised September 2017. See Appendix M of this Draft EIR.

22 Ibid.

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Table IV.I-8 Existing Ambient Noise Levels

Receptor Location

Noise-Sensitive Land Use

Measured Noise Levels, Leq (dBA)

CNEL (24-Hour)

Daytime Hours (7:00 A.M.–10:00 P.M.)

Nighttime Hours (10:00 P.M.–7:00 A.M.)

R1 Residential 58.6 54.8 60.5a





R6 Residential 55.8b 54.4b 61.4

a Estimated based on short-term (15-minute) noise measurement based on FTA procedures. b Levels shown for R6 represent the average for the entire daytime and nighttime periods.

Source: AES, 2017. See Appendix K to this Draft EIR.

hourly Leq noise levels based on specific information including the hourly traffic volume, vehicle type mix, vehicle speed, and lateral distance between the noise receptor and the roadway. To calculate the 24-hour CNEL levels, the hourly Leq levels were calculated during daytime hours (7:00 A.M. to 7:00 P.M.), evening hours (7:00 P.M. to 10:00 P.M.), and nighttime hours (10:00 P.M. to 7:00 A.M.).

The traffic noise prediction model calculates the 24-hour CNEL noise levels based on specific information including Average Daily Traffic Volume (ADT); percentages of day, evening, and nighttime traffic volumes relative to ADT; vehicle speed; and distance between the noise receptor and the roadway. Vehicle mix/distribution information used in the noise calculations is shown in Table IV.I-9 on page IV.I-18.

Table IV.I-10 on page IV.I-19 provides the calculated traffic noise levels for the analyzed local roadway segments based on existing traffic volumes. Traffic noise levels were calculated for the commuter peak hour, the peak hour preceding an on-site event, and a 24-hour period for both a weekday and weekend. As shown therein, the existing CNEL due to surface street traffic volumes ranges from 62.4 dBA CNEL along Spaulding Avenue (south of Wilshire Boulevard) to 74.0 dBA CNEL along Fairfax Avenue (north of 6th Street) during a weekday. The existing traffic noise levels during a weekend day ranges from 61.0 dBA CNEL along Ogden Drive (south of Wilshire Boulevard) to 73.3 dBA CNEL along Fairfax Avenue (north of 6th Street).

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Page IV.I-18

Table IV.I-9 Vehicle Mix for Traffic Noise Model

Vehicle Type

Percent of Average Daily Traffic (ADT), % Total Percent of

ADT per Vehicle Type

Daytime Hours (7 A.M.–7 P.M.)

Evening Hours (7 P.M.–10 P.M.)

Nighttime Hours (10 P.M.–7 A.M.)

Automobile 77.6 9.7 9.7 97.0

Medium Trucka 1.6 0.2 0.2 2.0

Heavy Truckb 0.8 0.1 0.1 1.0

Total 80.0 10.0 10.0 100.0

a Medium Truck—Trucks with 2 axles. b Heavy Truck—Trucks with 3 or more axles.

Source: AES, 2014.

(3) Existing Ground-Borne Vibration Levels

Based on field observations, the primary source of existing ground-borne vibration in the Project vicinity is vehicular travel (i.e., automobiles, refuse trucks, delivery trucks, construction trucks, school buses, and transit buses) on local roadways. According to the FTA technical study “Federal Transit Administration: Transit Noise and Vibration Impacts Assessments,” typical road traffic-induced vibration levels are unlikely to be perceptible by people. Specifically, the FTA study reports that “[i]t is unusual for vibration from sources such as buses and trucks to be perceptible, even in locations close to major roads.”23 Trucks and buses typically generate ground-borne vibration velocity levels of approximately 63 VdB at a distance of 50 feet, and these levels could reach 72 VdB when trucks and buses pass over bumps in the road. Per FTA, 75 VdB is the dividing line between barely perceptible and distinctly perceptible.24 Therefore, it is expected that the existing ground vibration environment in the vicinity of the Project Site would be below the perceptible level.

23 Federal Transit Administration (FTA), “Transit Noise and Vibration Impact Assessment,” 2006, p. 7-1. 24 Ibid, Figure 10-1.

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Page IV.I-19

Table IV.I-10 Existing Roadway Traffic Noise Levels

Roadway Segment Adjacent Land Use

Distance to Roadway

Center Line, (feet)

Calculated Traffic Noise Levels,a CNEL (dBA) Noise-

Sensitive Land Uses

Existing Noise Exposure Compatibility

Categoryb Weekday Weekend

Fairfax Avenue

– North of 6th St. Residential 35 74.0 73.3 Yes Normally Unacceptable

– Between 6th St. and Wilshire Blvd. Residential 40 72.9 72.6 Yes Normally Unacceptable

– South of Wilshire Blvd. Residential 40 72.5 71.8 Yes Normally Unacceptable

Ogden Drive

– South of Wilshire Blvd. Residential 30 62.8 61.0 Yes Conditionally Acceptable

Spaulding Avenue


Curson Avenue

– Between 6th St. and Wilshire Blvd. Residential 30 70.3 66.3 Yes Normally Unacceptable


Hauser Boulevard

– North of Wilshire Blvd. Residential 30 70.6 70.6 Yes Normally Unacceptable


Cochran Avenue

– North of Wilshire Blvd. Residential 25 70.2 67.2 Yes Normally Unacceptable


6th Street

– West of Fairfax Avenue Residential 30 70.0 68.2 Yes Normally Unacceptable

– Between Fairfax Ave. and Ogden Dr. Residential 40 71.6 69.9 Yes Normally Unacceptable

– Between Ogden Dr. and Curson Ave. Residential 40 71.7 69.8 Yes Normally Unacceptable

– East of Curson Ave. Residential 35 72.3 70.1 Yes Normally Unacceptable

IV.I Noise

Table IV.I-10 (Continued) Existing Roadway Traffic Noise Levels


Page IV.I-20


Distance to Roadway

Center Line, (feet)

Calculated Traffic Noise Levels,a CNEL (dBA) Noise-

Sensitive Land Uses

Existing Noise Exposure Compatibility

Categoryb Weekday Weekend

Wilshire Boulevard

– West of Fairfax Avenue Commercial 45 73.4 71.5 No Conditionally Acceptable

– Between Fairfax Ave. and Ogden Dr. Museum 45 72.2 71.0 No Conditionally Acceptable

– Between Ogden Dr. and Curson Ave. Museum 45 71.9 71.0 No Conditionally Acceptable

– East of Curson Ave. Commercial 45 72.3 71.5 No Conditionally Acceptable

8th Street

– Between Fairfax Ave. and Curson Ave. Residential 30 69.5 65.9 Yes Conditionally Acceptable

– East of Curson Ave. Residential 30 70.5 66.3 Yes Normally Unacceptable

a Detailed calculation worksheets are included in Appendix K. b Noise compatibility is based on the most stringent land use, per County’s land use compatibility as provided in Table IV.I-2 on page IV.I-6 and

the higher of the calculated CNEL during weekday and weekend days.

Source: AES, 2017.

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Page IV.I-21

3. Project Impacts

a. Methodology

(1) On-Site Construction Activities

Construction noise impacts due to on-site construction activities were evaluated by calculating the Project’s construction-related noise level at representative sensitive receptor locations and comparing these Project construction-related noise levels to the existing ambient noise levels (i.e., noise levels without construction noise from the Project). Construction noise associated with the Project was analyzed based on the Project’s potential construction equipment inventory, construction durations, and construction schedule. The construction noise model for the Project is based on construction equipment noise levels as published by Federal Highway Administration (FHWA) “Roadway Construction Noise Model (FHWA 2006).” The ambient noise levels at surrounding sensitive receptor locations were based on field measurement data (see Table IV.I-8 on page IV.I-17). The construction noise levels were then calculated for sensitive receptor locations based on the standard point source noise-distance attenuation factor of 6.0 dBA for each doubling of distance for area with hard surfaces or 7.5 dBA for area with soft surfaces (i.e., grass covered), as described above in Section 2.a(1)(b), Outdoor Sound Propagation. Additional noise attenuation was assigned to receptor locations where the line-of-sight to the Project Site was interrupted by the presence of intervening structures.

(2) Off-Site Construction Haul Trucks

Project-related off-site construction haul trucks noise impacts were analyzed using the FHWA’s TNM computer noise model. The TNM is the current Caltrans standard computer noise model for traffic noise studies. The model allows for the input of roadway, noise receivers, and sound barriers, if applicable. The construction-related off-site truck volumes were obtained from the Project’s construction traffic analysis (included in Appendix M to this Draft EIR). The TNM noise model calculates the hourly Leq noise levels generated by construction-related haul trucks. Noise impacts were determined by comparing the predicted noise level with that of the existing ambient noise levels along the Project’s haul route(s).

(3) On-Site Stationary Noise Sources (Operation)

On-site stationary point-source noise impacts were evaluated by: (1) identifying the noise levels that would be generated by the Project’s stationary noise sources, such as rooftop mechanical equipment, outdoor activities (e.g., use of outdoor dining areas and open space areas, and special events), parking facilities, loading and trash compactor; (2) calculating the noise level from each noise source at surrounding sensitive receptor

IV.I Noise


Page IV.I-22

property line locations; and (3) comparing such noise levels to ambient noise levels to determine significance.

(4) Off-Site Roadway Noise (Operation)

As discussed in Section 2.c, Existing Conditions, above, off-site roadway noise was analyzed using the FHWA TNM model and traffic data from the Traffic Study. Roadway noise conditions without the Project were calculated and compared to noise levels that would occur with implementation of the Project to determine Project-related noise impacts for operational off-site roadway noise.

(5) Construction Vibration

Ground-borne vibration impacts due to Project construction activities were evaluated by identifying potential vibration sources (i.e., construction equipment), estimating the vibration levels at the potentially affected receptor, and comparing with the Project significance thresholds, as described below.

(6) Operational Vibration

The primary sources of vibration associated with operation of the Project would include passenger vehicle circulation within the proposed parking structure, which would be similar to the existing vibration levels at the existing surface parking lot. The Project would also include a new central plant (located in the basement) and typical commercial-grade air ventilation system (located in mechanical wells at the roof level), which would incorporate vibration devices (to reduce the vibration transmission to the building). Typically, ground-borne vibration attenuates rapidly as a function of distance from the vibration source. Therefore, Project operations would not increase the existing vibration levels in the immediate vicinity of the Project Site, and as such, vibration impacts associated with Project operations would be less than significant. Accordingly, the ground-borne vibration analysis presented in this report is limited to Project-related construction activities.

b. Thresholds of Significance

Appendix G of the CEQA Guidelines provides a set of sample questions that address impacts with regard to noise. These questions are as follows:

Would the Project result in:

Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies;

IV.I Noise


Page IV.I-23

Exposure of persons to or generation of excessive ground-borne vibration or ground-borne noise levels;

A substantial permanent increase in ambient noise levels in the vicinity of the project above levels existing without the project;

A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project;

For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels?

For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels?

With regard to these questions from Appendix G to the CEQA Guidelines, the Initial Study included in Appendix A to this Draft EIR determined that since the Project would not be located within an airport land use plan, within two miles of a public airport or public use airport, or within the vicinity of a private airstrip, the Project would not expose people residing or working in the project area to excessive airport-related noise levels. Therefore, the Initial Study determined that impacts with regard to airport-related noise would not occur and would be clearly insignificant and unlikely to occur. As such, no further analysis of airport operation-related noise is necessary.

(1) Construction Noise

The analysis of construction noise was conducted based on the use of the more restrictive thresholds or limitations established between the City’s L.A. CEQA Thresholds Guide and the County’s Noise Ordinance. The City’s threshold for construction noise lasting more than 10 days is 5 dBA above the ambient, whereas the County’s construction noise limit is 65 dBA at multi-family residential uses (noise sensitive receptors in the vicinity of the Project Site). Thus, the more restrictive threshold or limit would depend on the existing ambient noise levels. Specifically, if the existing ambient noise level at the sensitive receptor is higher than 60 dBA, the County’s noise limit (i.e., 65 dBA) would be more restrictive than the City’s limit (ambient plus 5 dBA). However, if the existing ambient noise level at the multi-family residential use is less than 60 dBA, the City’s limit (e.g., ambient of 59 dBA plus 5 dBA is equal to 64 dBA) is more restrictive than the County’s limit (65 dBA). Based on these facts, the following thresholds have been utilized in determining significant impacts associated with construction activities:

IV.I Noise


Page IV.I-24

Construction activities would exceed the ambient noise levels by 5 dBA at noise-sensitive receptors with an existing ambient noise level of less than 60 dBA (Leq); or

Construction activities would exceed 65 dBA (Leq) at noise-sensitive receptors with an existing ambient level between 60 and 65 dBA (Leq); or

Construction activities would exceed the ambient at noise-sensitive receptors with an existing ambient level of 65 dBA (Leq) or greater.


Both the City and County do not have a significance threshold to assess vibration impacts with respect to building damage during construction. Thus, based on FTA guidance, impacts relative to ground-borne vibration associated with potential building damage would be considered significant if any of the following future events were to occur:

Project construction activities cause ground-borne vibration levels to exceed 0.5 PPV at the nearest off-site reinforced-concrete, steel or timber building.

Project construction activities cause ground-borne vibration levels to exceed 0.3 PPV at the nearest off-site engineered concrete and masonry building.

Project construction activities cause ground-borne vibration levels to exceed 0.2 PPV at the nearest off-site non-engineered timber and masonry building.

Project construction activities cause ground-borne vibration levels to exceed 0.12 PPV at buildings that are extremely susceptible to vibration damage, such as historic buildings.

As discussed in Section IV.C, Cultural Resources, of this Draft EIR, there are several historical resources within the Project vicinity. Generally, a significance threshold of 0.12 PPV is utilized for historic structures that are extremely susceptible to vibration damage. However, the historical resources in the immediate vicinity of the Project Site are two- to six-story and/or concrete structures. Single and two-story structures are considered to be non-engineered structures, while the structures that are three or more stories are considered to be engineered structures. None of the structures are considered to be extremely susceptible to vibration. Therefore, the assessment of potential building damage from vibration due to construction activities compares the estimated vibration levels generated during construction of the Project to the 0.2 PPV significance threshold for non-engineered buildings applicable to single or two-story structures, the 0.3 PPV significance threshold for engineered concrete masonry buildings (applicable to buildings that are three-story structures and higher), and the 0.5 PPV significance threshold for reinforced-concrete, steel, or timber buildings.

IV.I Noise


Page IV.I-25

With respect to human annoyance, the County has a vibration limit of 0.01 inch/second, which is equal to 80 VdB. Therefore, construction vibration impacts associated with human annoyance would be significant if the following were to occur:

Project construction activities cause ground-borne vibration levels to exceed 80 VdB at the off-site sensitive uses.

(3) Operational Noise

In the context of the above questions from Appendix G of the CEQA Guidelines, the thresholds of significance for the Project’s on-site operational noise sources are based on the County’s Noise Ordinance (i.e., not to exceed the ambient), which are more stringent than the City’s Noise Ordinance (i.e., increase the ambient by 5 dBA). The City and the County Noise Ordinances do not apply to off-site traffic traveling on public roads. However, the L.A. CEQA Threshold Guide does include a significance threshold for off-site traffic noise. Based on this context, potential operational noise impacts would be considered significant if:

Project off-site noise sources (i.e., roadway traffic noise) cause the ambient noise levels measured at the property line of affected noise-sensitive uses to increase by 3 dBA in CNEL to or within the “normally unacceptable” or “clearly unacceptable” category (see Table IV.I-2 on page IV.I-6 for a description of these categories); or

Project off-site noise sources cause the ambient noise levels measured at the property line of affected noise-sensitive uses to increase by 5 dBA in CNEL or greater; or

Project on-site (i.e., non-roadway) noise sources such as outdoor building mechanical/electrical equipment, outdoor activities, or parking facilities generate noise levels that would exceed the ambient noise level (Leq) at noise sensitive receptors.

As discussed in the Initial Study prepared for the Project, which is included in Appendix A of this Draft EIR, the Project is not located within an airport land use plan or within two miles of a public or private airport, or within the vicinity of a private airstrip. Therefore, the Project would not expose people residing or working in the Project area to excessive noise levels associated with a public or private airport or a private airstrip. As such, no further analysis of airport operation-related noise is necessary.

c. Project Design Features

The following project design features are proposed with regard to noise:

IV.I Noise


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Project Design Feature I-1:

Power construction equipment (including combustion engines), fixed or mobile, will be equipped with state-of-the-art noise shielding and muffling devices (consistent with manufacturers’ standards). All equipment will be properly maintained to assure that no additional noise, due to worn or improperly maintained parts, would be generated. The construction contractor will periodically document on-site conditions with photographs to demonstrate that the equipment has been maintained in accordance with manufacturer’s specifications.

Staging and delivery areas will be located as far as feasible from existing residences.

To the extent feasible, hydraulic equipment will be used instead of pneumatic impact tools and electrical powered equipment will be used instead of diesel powered equipment.

Idling of construction equipment, when not in use or during loading/unloading will be minimized.

Stationary equipment will be placed as far as feasible from existing residences.

A conspicuous sign will be posted at entrances to construction with contact information for residents to report any noise or other complaints.

Project Design Feature I-2: Project construction will not include the use of driven (impact) pile systems.

Project Design Feature I-3: All outdoor mounted mechanical equipment will be enclosed or screened from off-site noise-sensitive receptors. The enclosure or screen shall provide a minimum Sound Transmission Class (STC) 20 rating and break the line-of-sight to the off-site sensitive receptors.

Project Design Feature I-4: Outdoor amplified sound systems (e.g., speaker and stereo systems, amplification systems, or other sound-producing devices) will be designed so as not to exceed the maximum noise level of 75 dBA (Leq-1hr) at a distance of 25 feet from the amplified sound systems location at the outdoor dining areas and 95 dBA (Leq-

1hr) at a distance of 25 feet for the amplified sound systems during special events.

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Page IV.I-27

d. Analysis of Project Impacts

(1) Construction Noise

Project construction is anticipated to commence in 2018 and be completed by 2023. Construction activities would include demolition of several existing facilities, grading and excavation, and construction of new structures and related infrastructure. It is estimated that the Project would require approximately 151,140 cubic yards of cut, including approximately 127,600 cubic yards of cut from LACMA East/Spaulding Lot and approximately 23,400 cubic yards of cut from the Ogden Lot, all of which would be exported. The Project would require approximately 37,400 cubic yards of fill.

(a) On-Site Construction Noise

Noise impacts from Project construction activities occurring within the Project Site would be a function of the noise generated by construction equipment, the location of the equipment, the timing and duration of the noise-generating construction activities, and the relative distance to noise sensitive receptors. Construction activities would generally include demolition, grading and excavation, and building construction. Each stage of construction would involve the use of various types of construction equipment and would, therefore, have its own distinct noise characteristics. Demolition generally involves the use of backhoes, front-end loaders, and heavy-duty trucks. Grading and excavation typically requires the use of earth moving equipment, such as excavators, front-end loaders, and heavy-duty trucks. Building construction typically involves the use of cranes, forklifts, concrete trucks, and delivery trucks. Noise from construction equipment would generate both steady-state and episodic noise that could be heard within and adjacent to the Project Site.

Individual pieces of construction equipment that would be used for Project construction produce maximum noise levels (Lmax) of 74 dBA to 90 dBA at a reference distance of 50 feet from the noise source, as shown in Table IV.I-11 on page IV.I-28. These maximum noise levels would occur when equipment is operating under full power conditions (i.e., the equipment engine at maximum speed). However, equipment used on construction sites often operates under less than full power conditions, or part power. To more accurately characterize construction-period noise levels, the average (Hourly Leq) noise level associated with each construction stage is calculated based on the quantity, type, and usage factors for each type of equipment that would be used during each

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Table IV.I-11 Construction Equipment Noise Levels

Equipment Estimated Usage Factora

%

Typical Noise Level at 50 feet from Equipment, dBA

(Lmax)

Air Compressor 40 78

Cement and Mortar Mixer 50 80

Concrete Mixer Truck 40 79

Concrete Saw 20 90

Crane 16 81

Drill Rig 20 84

Forklift 10 75

Generator 50 81

Grader 40 85

Dump/Haul Truck 40 76

Excavator 40 81

Paver 50 77

Pump 50 81

Roller 20 80

Rubber Tired Loader 40 79

Tractor/Loader/Backhoe 40 80

Delivery Truck 40 74

Welders 40 74

a Usage factor represents the percentage of time the equipment would be operating at full speed.

Source: FHWA Roadway Construction Noise Model User’s Guide, 2006.

construction stage.25 These noise levels are typically associated with multiple pieces of equipment operating simultaneously.

Table IV.I-12 on page IV.I-29 provides the estimated construction noise levels for various construction stages of the Museum Building at the off-site noise sensitive receptors. The estimated noise levels represent the worst-case scenario in which all construction equipment was assumed to operate simultaneously and was assumed to be located at the construction area nearest to the affected receptors. These assumptions

25 Pursuant to the FHWA Roadway Construction Noise Model User’s Guide, 2005, the usage factor is the

percentage of time during a construction noise operation that a piece of construction is operating at full power.

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Page IV.I-29

Table IV.I-12 Construction Noise Impacts—Museum Building

Off-Site Receptor Location

Approximate Linear Distance from Receptor

to Project Construction

Area (feet)

Estimated Construction Noise Levels by Construction Phases, Leq (dBA)

Measured Ambient

Noise Levels, Leq (dBA)

Significance Threshold,a

Leq (dBA) Significant

Impact? Demolition Grading/

Excavation

Building Structure/

Interior Landscape/ Finishing

R1 25 79.6 76.4 74.8 73.8 58.6 63.6 Yes

R2 165 78.2 74.5 74.2 71.7 57.8 62.8 Yes

R3 875 60.1 54.5 55.0 51.0 64.0 65.0 No

R4 365 69.6 64.0 64.5 60.5 69.9 69.9 No

R5 565 70.1 64.5 65.0 61.0 63.0 65.0 Yes

R6 25 79.6 76.4 74.8 73.8 55.8 60.8 Yes

a Significance thresholds are equivalent to the measured daytime ambient noise levels plus 5 dBA where the ambient noise level is less than

60 dBA; 65 dBA where the ambient noise is between 60 and 65 dBA; and equal to the ambient where the ambient noise level is greater than 65 dBA.

Source: AES, 2017.

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Page IV.I-30

represent the worst-case noise scenario as construction activities would typically be spread out throughout the entire site further away from the affected receptors. As indicated in Table IV.I-12 on page IV.I-29, the estimated construction noise levels at off-site receptors R3 and R4 would be below the significance threshold. At receptors R1, R2, R5 and R6, the estimated construction-related noise levels would exceed the significance threshold by 5.1 dBA at receptor R5 and to up to 18.8 dBA at receptor R6. Therefore, without mitigation, noise impacts associated with the Project’s on-site construction activities for the Museum Building would be significant.

Table IV.I-13 on page IV.I-31 provides the estimated construction noise levels at the off-site noise sensitive receptors in the vicinity of the Ogden Parking Structure. As indicated in Table IV.I-13, the estimated noise levels would be below the significance threshold at all off-site noise sensitive receptors, with the exception of receptor R5. The construction-related noise levels at receptor R5 would exceed the significance threshold by up to 16.3 dBA. Therefore, without mitigation, noise impacts associated with the Project’s on-site construction activities for the Ogden Parking Structure would be significant.

(b) Off-Site Construction Noise

In addition to on-site construction noise sources, materials delivery, concrete mix, haul trucks, and construction worker vehicles would require access to the Project Site during the construction phase. The major noise sources associated with off-site construction trucks would be associated with haul and delivery trucks. Construction trucks would generally access the Project Site from the I-10 Freeway. Inbound traffic would exit I-10 at La Brea Avenue, travel northbound to Wilshire Boulevard and continue westbound on Wilshire Boulevard to the Project Site. Outbound traffic would travel eastbound on Wilshire Boulevard to La Brea Avenue, then southbound on La Brea Avenue to access the I-10.

The peak period of construction with the highest number of construction trucks would occur during the grading/excavation phase for the Museum Building.26 During this phase, there would be a maximum of 165 construction trucks (150 haul and 15 deliveries) coming to and leaving the Project Site (equal to 330 total trips) per day. The hourly truck trips were calculated based on an eight-hour period (typical workday) and a uniform distribution of trips, which would result in a maximum of 42 truck trips per hour. In addition, there would be a total of 60 worker trips to and from the Project Site on a daily basis during the grading/excavation phase for the Museum Building. For the Ogden Parking Structure, 26 Gibson Transportation Consulting, Inc., Traffic Study for the Building for the Permanent Collection of the

Los Angeles County Museum of Art Project, March 2017, revised September 2017. See Appendix M of this Draft EIR.

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Table IV.I-13 Construction Noise Impacts—Ogden Parking Structure

Off-Site Receptor Location

Approximate Linear Distance from Receptor

to Project Construction

Area (feet)

Estimated Construction Noise Levels by Construction Phases, Leq (dBA)

Measured Ambient

Noise Levels, Leq (dBA)

Significance Threshold,a

Leq (dBA) Significant

Impact? Demolition Grading/

Excavation Building Structure

Landscape/ Finishing

R1 610 58.7 56.6 53.6 48.4 58.6 63.6 No

R2 1,125 53.4 51.3 48.3 43.1 57.8 62.8 No

R3 1,755 49.5 47.4 44.4 39.3 64.0 65.0 No

R4 1,180 53.0 50.9 47.9 42.7 69.9 69.9 No

R5 10 81.3 76.4 72.7 72.2 63.0 65.0 Yes

R6 905 55.3 53.2 50.2 45.0 55.8 60.8 No

a Significance thresholds are equivalent to the measured daytime ambient noise levels plus 5 dBA where the ambient noise level is less than

60 dBA; 65 dBA where the ambient noise is between 60 and 65 dBA; and equal to the ambient where the ambient noise level is greater than 65 dBA.

Source: AES, 2017.

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there would be a maximum of 26 truck trips and 25 work trips during the grading/excavation phase. There would also be construction delivery truck trips (up to 190 truck trips per day) during other construction phases of the Project, but such trips would be significantly less than the 330 truck trips under the grading phase for the Museum Building.

Table IV.I-14 on page IV.I-33 presents the estimated construction-related haul truck noise levels along the proposed haul routes with noise sensitive receptors. As indicated on Table IV.I-14, the noise level generated by haul trucks would be well below the existing daytime ambient noise level at the noise sensitive receptors along the haul routes. In addition, haul trucks for the Ogden Parking Structure would access the Ogden Site via Ogden Drive (from Wilshire Boulevard). The estimated noise level from the haul trucks, during the grading phase for the Ogden Parking Structure, would be approximately 62.3 dBA at the residential use along Ogden Drive (Receptor R6), which would be below the existing daytime ambient noise level of 63.0 dBA. Therefore, noise impacts from off-site construction traffic would be less than significant.


Construction activities can generate varying degrees of ground vibration, depending on the construction procedures and the type of construction equipment used. The operation of construction equipment generates vibrations that spread through the ground and diminish in amplitude with distance from the source. The effect on buildings located in the vicinity of the construction site often varies depending on soil type, ground strata, and construction characteristics of the receptor buildings. The results from vibration can range from no perceptible effects at the lowest vibration levels to low rumbling sounds and perceptible vibration at moderate levels. However, ground-borne vibrations from construction activities rarely reach levels that damage structures.

(a) On-Site Construction Vibration

Project construction activities would generate ground-borne vibration during site demolition and excavation/grading activities when heavy construction equipment, such as large bulldozers, would be used. The FTA has published standard vibration velocities for various construction equipment operations. The typical vibration levels (in terms of inch per second Peak Particle Velocity, PPV) at a reference distance of 25 feet for construction to be used during Project construction are listed in Table IV.I-15 on page IV.I-34.27 Also included in Table IV.I-15 are the estimated vibration velocity levels at the nearest off-site structures to the Project construction area, including nearby historical resources.

27 FTA, “Transit Noise and Vibration Impact Assessment,” May 2006.

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Table IV.I-14 Off-Site Construction Haul Truck Noise Impacts

Construction Phase

Estimated Number of Trips per Hour,a

Construction Truck/Worker

Estimated Haul Truck Noise Levels Along the Project Haul Routes (Wilshire Boulevard

and La Brea Avenue), dBA (Leq)

Museum Building

Ogden Parking Structure Museum Building

Ogden Parking Structure

Demolition 23/70 2/15 65.4 55.5

Grading 42/60 27/25 67.7 65.7

Parking Structure Foundation

24/400 11/45 67.5 62.4

Building Construction

13/385 N/A 66.0 N/A

Paving/Concrete/ Landscape

5/50 4/50 59.8 59.2

Existing Ambient Noise Levels Along the Project Haul Routes,b Leq (dBA) – Wilshire Blvd./La Brea Ave.

72.4/73.3 72.4/73.3

Significance Threshold,c Leq (dBA) 72.4/73.3 72.4/73.3

a For construction trucks, the number of hourly trips is based on an hourly average, assuming a uniform

distribution of trips over an 8-hour work day. For worker vehicles, the number of hourly trips is based on half of the worker trips that would arrive in one hour to represent a conservative analysis.

b Ambient noise levels along the haul routes are calculated based on the existing traffic volumes along Wilshire Boulevard and La Brea Avenue.

c Significance thresholds are equivalent to the existing ambient noise levels or 75 dBA (County’s noise standard for construction mobile source at residential uses), whichever is lower.

Source: AES, 2017.

As indicated in Table IV.I-15 on page IV.I-34, vibration velocities from typical heavy construction equipment operations that would be used during construction of the Project would range from 0.003 to 0.210 PPV at 25 feet from the equipment. The estimated vibration velocity levels (from all construction equipment) would be well below the Project significance thresholds at all off-site building structures, with the exception of the multi-family residential building on Ogden Drive (adjacent to the future Ogden Parking Structure). This potential vibration impact would only occur when heavy construction equipment operates within 12 feet of the adjacent multi-family residential building.28 However, Mitigation Measure I-2 provided below would reduce the potential vibration impact during construction to a less-than-significant level.

28 The 12 feet distance is calculated distance, which heavy construction equipment (e.g., large bulldozer

and caisson drilling) would diminish to below the 0.3 threshold.

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Table IV.I-15 Construction Vibration Impacts—Building Damage

Off-Site Building Structurea

Estimated Vibration Velocity Levels at the Exterior of the Nearest Off-Site Structures from the Project

Construction Equipment,b inch/second (PPV) Significance Threshold,

PPV Sig.

Impact? Large

Bulldozer Caisson Drilling

Loaded Trucks

Jack-hammer

Small Bulldozer

FTA Reference Vibration Levels at 25 feet

0.089 0.089 0.076 0.035 0.003 — —

Multi-family residential building to the north on 6th St.

0.002 0.002 0.002 0.001 <0.001 0.3c No

Multi-family residential building to the south on Spaulding Ave.

0.089 0.089 0.076 0.035 0.003 0.3c No

Multi-family residential building to the south on Ogden Dr.

0.352 0.352 0.300 0.138 0.012 0.3c Yes

Commercial building at 5900 Wilshire Blvd., west of the Project Site

0.024 0.024 0.020 0.009 0.001 0.3c No

6067 Wilshire Blvd.—Four-story building (AMPAS under renovation)

0.002 0.002 0.002 0.001 <0.001 0.3c No

5950 Wilshire Blvd.—Two-story office building (concrete)

0.005 0.005 0.005 0.002 <0.001 0.3c No

724 S. Genesee Ave.—Two-story apartment building

0.005 0.005 0.004 0.002 <0.001 0.2d No

5850 Wilshire Blvd.—Three-story office building

0.089 0.089 0.076 0.035 0.003 0.3c No

5828 Wilshire Blvd.—Three-story office building

0.005 0.005 0.005 0.002 <0.001 0.3c No

5820 Wilshire Blvd.—Six-story office building

0.002 0.002 0.002 0.001 <0.001 0.3c No

5814 Wilshire Blvd.—Two-story building (Craft & Folk Art Museum)

0.003 0.003 0.002 0.001 <0.001 0.2d No

5905 Wilshire Blvd.—Pavilion for Japanese Art

0.089 0.089 0.076 0.035 0.003 0.3c No

IV.I Noise

Table IV.I-15 (Continued) Construction Vibration Impacts—Building Damage


Page IV.I-35

Off-Site Building Structurea

Estimated Vibration Velocity Levels at the Exterior of the Nearest Off-Site Structures from the Project

Construction Equipment,b inch/second (PPV) Significance Threshold,

PPV Sig.

Impact? Large

Bulldozer Caisson Drilling

Loaded Trucks

Jack-hammer

Small Bulldozer

5801 Wilshire Blvd.—La Brea Tar Pit Museum

0.002 0.002 0.002 0.001 <0.001 0.3c No

a Represents off-site building structures located nearest to the Project Site to the North, South, East and

West. b Vibration level calculated based on FTA reference vibration level at 25 distance. c FTA criteria for engineered concrete and masonry building. d FTA criteria for non-engineered timber and masonry building.

Source: FTA, 2006; AES, 2017. See Appendix K to this Draft EIR.

Construction of the Project would require a temporary falsework structure spanning over Wilshire Boulevard. The future Los Angeles County Metropolitan Transportation Authority (Metro) Purple Line would be approximately 70 feet below grade (underneath Wilshire Boulevard). The footings of the columns for the temporary falsework structure would be located within the existing Wilshire Boulevard median. In addition, permanent foundations would be located within the Project’s property lines north and south of Wilshire Boulevard. Due to distance attenuation, construction of the footings for the columns for the temporary falsework structure and the permanent foundations would not result in significant vibration impacts to Metro’s Purple Line.

Table IV.I-16 on page IV.I-36 provides the estimated vibration levels relative to human annoyance due to construction equipment at the off-site sensitive uses. As indicated in Table IV.I-16, the estimated ground-borne vibration levels from construction equipment would be below the significance threshold for human annoyance at off-site sensitive receptors R2, R3 and R4. However, the estimated ground-borne levels would exceed the significance threshold for human annoyance at receptors R1, R5, and R6. Therefore, without mitigation, vibration impacts on human annoyance during the construction period would be potentially significant.

(b) Off-Site Construction Vibration

Haul trucks during construction would generate ground-borne vibration as they travel along the Project designated haul routes. Thus, an analysis of potential vibration impacts

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Page IV.I-36

Table IV.I-16 Construction Vibration Impacts—Human Annoyance

Equipment

Reference Vibration Velocity

Levels at 25 ft., VdB

Estimated Vibration Velocity Levels at the Off-Site Sensitive Uses, VdB

R1 R2 R3 R4 R5 R6

Large Bulldozer 87 87 62 41 52 99 87

Caisson Drilling 87 87 62 41 52 99 87

Loaded Trucks 86 86 61 40 51 98 86

Jackhammer 79 79 54 33 44 91 79

Small Bulldozer 58 58 33 12 23 70 58

Significance Threshold, VdB 80 80 80 80 80 80

Significant Impact? Yes No No No Yes Yes

Source: FTA, 2006, AES, 2017.

associated with building damage from ground-borne vibration along the local haul route was conducted. Based on FTA data, the vibration generated by a typical truck would be approximately 63 VdB (0.006 PPV) at a distance of 50 feet from the truck.29 At the shortest distance between haul trucks and sensitive receptors, haul/delivery trucks would be approximately 25 feet from nearby sensitive receptors along Wilshire Boulevard and La Brea Avenue (between the I-10 Freeway and the Project Site). Vibration levels generated by the haul trucks at this distance would be 0.016 PPV, which would be well below the most stringent building damage threshold of 0.12 PPV. In addition, the estimated vibration levels along the haul routes would be approximately 72 VdB, which would be below the human annoyance significance threshold of 80 VdB (applicable to at residential uses). Therefore, potential impacts associated with vibration from delivery/haul trucks traveling along the designated haul routes would be less than significant.

(3) Operational Noise

This section provides a discussion of potential operational noise impacts on nearby noise-sensitive receptors. Specific operational noise sources addressed herein include on-site stationary noise sources, which consist of outdoor mechanical equipment (i.e., Central plant and rooftop air ventilation HVAC units), activities associated with use of the outdoor spaces (i.e., outdoor dining, gatherings and special events), loading/trash compactor, and parking facilities, and off-site mobile (roadway traffic) noise sources.

29 FTA, “Transit Noise and Vibration Impact Assessment,” Figure 7-3, May 2006.

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Page IV.I-37

(a) On-Site Stationary Noise Sources

(i) Mechanical Equipment

As part of the Project, new rooftop mechanical equipment (i.e., HVAC condenser units) would be located in mechanical wells at the roof level. The existing central plant located within the Ahmanson Building would be removed and replaced with new systems located in the basement of the new Museum Building. In addition, the new central plant systems would include three or four cooling towers, to be located at the west side of the Resnick Pavilion on LACMA West. Table IV.I-17 on page IV.I-38 presents the estimated noise levels at the off-site receptor locations from operation of the Project mechanical equipment. As indicated in Table IV.I-17, the estimated noise levels from the mechanical equipment would range from 31.5 dBA (Leq) at receptor location R6 to 39.6 dBA (Leq) at receptor location R1, which would be well below the existing ambient noise levels. As such, the estimated noise levels at all off-site receptor locations would be below the significance threshold. Therefore, noise impacts from mechanical equipment would be less than significant.

(ii) Ogden Parking Structure

The Project includes a new 260-space seven-level parking structure (five above grade and two subterranean levels) to be located at the Ogden Lot. Sources of noise within the parking structures would primarily include car movements (i.e., engine noise), doors opening, people talking, and intermittent car alarms. Since the subterranean parking levels would be fully enclosed on all sides, noise generated within the subterranean parking garages would be effectively shielded from off-site sensitive receptor locations in immediate the vicinity of the Project Site. However, the above grade parking levels would have openings for ventilation. Table IV.I-18 on page IV.I-38 presents the estimated noise levels from new parking structure at the off-site sensitive receptors. As indicated in Table IV.I-18, the estimated noise levels at all off-site locations would be below the Project significance threshold. Therefore, noise impacts from the parking structure would be less than significant.

(iii) Outdoor Areas

The Project includes three outdoor dining areas (one restaurant and two cafés), and outdoor open space areas. The outdoor dining areas would accommodate up to 50 people at the restaurant located on LACMA East, 40 people at the café located on the southern portion of LACMA East, and 38 people at the café located on the Spaulding Lot. For the noise analysis, it was conservatively estimated that up to 6,800 people could be within the park area on LACMA East and up to 4,000 people could gather at the southern park area on the Spaulding Lot. These numbers are based on the maximum permitted occupancies

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Table IV.I-17 Estimated Noise Levels from Mechanical Equipment

Receptor Location

Existing Daytime Ambient Noise

Levels, dBA (Leq)

Estimated Noise Levels from Mechanical

Equipment, dBA (Leq)

Significance Thresholda

Significant Impact?

R1 58.6 39.6 58.6 No

R2 57.8 36.1 57.8 No

R3 64.0 35.1 64.0 No

R4 69.9 38.4 69.9 No

R5 63.0 38.4 63.0 No

R6 55.8 31.5 55.8 No

a Significance thresholds are equivalent to the measured ambient noise levels (see Table IV.I-8 on page

IV.I-17).

Source: AES, 2017.

Table IV.I-18 Estimated Noise Levels from the Ogden Parking Structure

Receptor Location


Levels, dBA (Leq)

Estimated Noise Levels from Ogden Parking

Structure, dBA (Leq)


Significant Impact?

R1 58.6 38.2 58.6 No

R2 57.8 30.0 57.8 No

R3 64.0 25.1 64.0 No

R4 69.9 31.1 69.9 No

R5 63.0 53.3 63.0 No

R6 55.8 33.7 55.8 No

a Significance thresholds are equivalent to the measured ambient noise levels (see Table IV.I-8 on

page IV.I-17).

Source: AES, 2017.

allowed per Code. The number of people that would occupy these outdoor areas would be substantially smaller. In particular, the number of persons that would occupy the outdoor areas of the Spaulding would not be anticipated to exceed 500 given the theater would only seat 300 people. To evaluate noise from these areas, reference noise levels of 65 dBA and 62 dBA Leq at a distance of 3.3 feet were used to represent males and females speaking in

IV.I Noise


Page IV.I-39

a raised voice at the outdoor dining areas, respectively.30 People at the outdoor open spaces (northern and southern parks) are assumed to speak in normal voices, 58 dBA Leq for a male and 55 dBA Leq for a female at a distance of 3.3 feet. It was assumed that up to 50 percent of the people (half of which would be male and the other half female) would be talking at the same time. In order to comply with the County’s Noise Ordinance, the amplified sound system at the restaurant outdoor seating areas would be designed so as not to exceed a maximum noise level of 75 dBA (Leq) at a distance of 25 feet from the amplified sound system. Table IV.I-19 on page IV.I-40 presents the estimated noise levels from the outdoor areas at the off-site sensitive receptors. As indicated in Table IV.I-19, the estimated noise levels at all off-site locations would not exceed the existing ambient noise levels. Therefore, noise impacts from outdoor areas would be less than significant.

(iv) Special Events

The Project includes special events that would occur within three primary areas: (1) at the west side of the Museum Building at the existing Main Plaza (Special Event 1); (2) north of the Museum Building at the existing Brown Amphitheater (Special Event 2); and (3) near the center of the Project Site south of the existing Pavilion for Japanese Art (Informal Special Event). The special events would accommodate crowds of up to 2,000–3,000 people at Special Event 1, Special Event 2, and at the Informal Special Event. For the noise analysis, noise levels of 75 dBA and 71 dBA (Leq) at a distance of 3.3 feet for

males and females (speaking in loud voice), respectively were used.31 As specified by Project Design Feature I-4, the proposed amplified sound system for the special events would generate a sound level of approximately 95 dBA (Leq) at a distance of 25 feet. In addition, the three special event areas would not occur concurrently.

Table IV.I-20 on page IV.I-41 presents the estimated noise levels from the event spaces at the off-site sensitive receptors. As indicated in Table IV.I-20, the estimated noise levels from special events would be below the significance threshold at all off-site receptor locations. Therefore, noise impacts from special events would be less than significant.

(v) Loading and Trash Compactor Activities

Project deliveries would occur at two delivery/loading locations, one at the northern portion of the Project Site (with access from 6th Street) and one at the southern portion of the Spaulding Lot (with access from Spaulding Avenue). The Project would include

30 Harris, Cyril M., Handbook of Acoustical Measurements and Noise Control, Third Edition, 1991, Table 16.1. 31 Harris, Cyril M., Handbook of Acoustical Measurements and Noise Control, Third Edition, 1991, Table 16.1.

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Page IV.I-40

Table IV.I-19 Estimated Noise Levels from Outdoor Areas

Receptor Location

Existing Ambient

Noise Levels, dBA (Leq)

Estimated Noise Levels from the Outdoor Spaces, dBA (Leq)

Significance Thresholdc

Significant Impact?

Outdoor Dininga Park Areasb

Composite of Outdoor Dining and Park Areas

R1 58.6 39.5 49.7 50.1 58.6 No

R2 57.8 51.3 46.7 52.6 57.8 No

R3 64.0 36.9 37.1 40.0 64.0 No

R4 69.9 39.1 42.0 43.8 69.9 No

R5 63.0 34.0 34.0 37.0 63.0 No

R6 55.8 46.3 51.8 52.9 55.8 No

a Assumed capacity of up to 128 people at the outdoor dining areas and amplified sound system with

maximum sound level of 75 dBA (Leq) at 25 feet distance. b Assumed up to 6,900 people at the northern park area and 4,000 people at the southern park area. c Significance thresholds are equivalent to the measured ambient noise levels (see Table IV.I-8 on page

IV.I-17).

Source: AES, 2017.

one trash compactor located within the northern portion of the Project Site, near the delivery/loading area. Based on measured noise levels from typical loading dock facilities, delivery trucks (while idling at the loading dock) could generate noise levels of approximately 71 dBA (Leq) at a distance of 50 feet from the noise source. In addition, a trash compactor would generate noise levels of approximately 66 dBA (Leq) at a distance of 50 feet. As shown in Table IV.I-21 on page IV.I-42, the estimated noise levels from loading and trash compactor operations at all off-site locations would be well below the existing ambient noise levels. Therefore, noise impacts from loading and trash compactor operations would be less than significant.

(b) Off-Site Traffic (Mobile Sources)

(i) Future Plus Project

Future roadway noise levels were calculated along the 21 selected off-site roadway segments in the vicinity of the Project Site. The off-site roadway noise levels were calculated using the traffic data provided in the Traffic Study. As discussed in the Traffic Study, the Project trip generation factored a temporary increase in daily attendance of up to 750 weekday visitors and 1,250 Saturday visitors immediately following the opening of the Project (an increase of up to approximately 23 percent over average daily attendance).

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Page IV.I-41

Table IV.I-20 Estimated Noise Levels from Special Events

Receptor Location

Existing Daytime Ambient

Noise Levels, dBA (Leq)

Estimated Noise Levels from the Outdoor Special Events, dBA (Leq)


Significant Impact?

Special Event 1

Special Event 2

Informal Special Event

R1 58.6 37.6 40.5 48.9 58.6 No

R2 57.8 39.3 39.1 40.4 57.8 No

R3 64.0 45.4 46.1 58.2 64.0 No

R4 69.9 60.8 62.6 65.7 69.9 No

R5 63.0 56.9 57.1 34.2 63.0 No

R6 55.8 35.2 36.8 40.3 55.8 No

a Significance thresholds are equivalent to the measured daytime ambient noise levels (see Table IV.I-8

on page IV.I-17).

Source: AES, 2017.

These attendance assumptions would generate 668 net new trips during the weekday and 763 net new trips during the weekend.

The off-site traffic noise impacts are presented in Table IV.I-22 on page IV.I-43. The calculated CNEL levels overestimate noise levels as they are calculated in front of the roadways and do not account for the presence of any physical sound barriers or intervening structures. As shown therein, the Project would result in a maximum increase of 1.2 dBA in traffic-related noise levels along Ogden Drive during the weekday and 1.6 dBA during the weekend. The estimated noise increase due to Project-related traffic would be well below the 3-dBA significance threshold. Therefore, off-site traffic noise impacts associated with Future Plus Project conditions would be less than significant.

(ii) Existing Plus Project

The analysis of off-site traffic noise impacts above was based on the incremental increase in traffic noise levels attributable to Future With Project conditions as compared to Future Without Project conditions. Additional analysis was made to determine the potential noise impacts based on the increase in noise levels due to Project-related traffic compared with the existing baseline traffic noise conditions.

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Table IV.I-21 Estimated Noise Levels from Loading and Trash Compactor Operations

Receptor Location


Levels, dBA (Leq)

Estimated Noise Levels from Loading,

dBA (Leq)

Estimated Noise Levels from

Trash Compactor, dBA (Leq

Significance Thresholdb

Significant Impact?

R1 58.6 54.2 11.9 58.6 No

R2 57.8 43.1 6.8 57.8 No

R3 64.0 30.8 26.4 64.0 No

R4 69.9 42.8 37.4 69.9 No

R5 63.0 40.3 29.5 63.0 No

R6 55.8 46.7 8.1 55.8 No

a Significance thresholds are equivalent to the measured ambient noise levels (see Table IV.I-8 on page

IV.I-17).

Source: AES, 2017.

Table IV.I-23 on page IV.I-45 presents the off-site traffic noise impacts as compared with existing conditions, for a typical weekday and weekend day. As indicated therein, the maximum Project-related traffic noise increase would be 1.2 dBA during weekday and 1.9 dBA during weekend, along the Ogden Drive. The estimated increase in off-site traffic noise levels would be below the 3-dBA CNEL significance threshold. Therefore, off-site traffic noise impacts associated with the Existing Plus Project traffic conditions would be less than significant.

(c) Composite Noise Level Impacts from Project Operations

In addition to considering the potential noise impacts to neighboring noise-sensitive receptors from each specific off-site and on-site noise source (i.e., traffic, mechanical equipment, parking, loading/trash compactor, use of outdoor areas, special events), an evaluation of the potential composite noise level increase (i.e., noise levels from all noise sources combined) at the analyzed sensitive receptor locations was also performed. Table IV.I-24 on page IV.I-47 presents the estimated composite noise levels in terms of CNEL at the off-site sensitive receptors. As indicated in Table IV.I-24, the Project would result in an increase of 0.6 dBA (at Location R6) to 3.8 dBA (at Location R5) at the off-site receptors in the vicinity of the Project Site. The estimated composite noise level at Location R5 is 66.1 dBA CNEL, which is within the “conditionally acceptable” land use category. As such, the estimated 3.8 dBA increase in noise levels at Location R5 due to Project operation would be below the 5 dBA CNEL significance threshold (applicable to noise level within the “normally acceptable” or “conditionally acceptable” land use categories). Therefore, composite noise level impacts due to the Project operations would be less than significant.

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Table IV.I-22 Roadway Traffic Noise Impacts—Future Plus Project


Calculated Traffic Noise Levels,a (dBA)

Significant Impacts?

Future Without Project Future With Project Traffic Noise Levels

Increase Due to Project

Weekday Weekend Weekday Weekend Weekday Weekend

Fairfax Avenue

– North of 6th St. Residential 74.5 73.8 74.5 73.9 0.0 0.1 No

– Between 6th St. and Wilshire Blvd.

Residential 73.5 73.1 73.5 73.1 0.0 0.0 No

– South of Wilshire Blvd. Residential 72.9 72.3 72.9 72.3 0.0 0.0 No

Ogden Drive


Spaulding Avenue

– South of Wilshire Blvd. Residential 62.7 63.7 61.3 62.6 -1.4 -1.1 No

Curson Avenue


Residential 70.7 67.0 70.7 67.0 0.0 0.0 No


Hauser Boulevard

– North of Wilshire Blvd. Residential 71.0 70.9 71.0 70.9 0.0 0.0 No


Cochran Avenue



IV.I Noise

Table IV.I-22 (Continued) Roadway Traffic Noise Impacts—Future Plus Project


Page IV.I-44




Future Without Project Future With Project Traffic Noise Levels



6th Street

– West of Fairfax Avenue Residential 70.4 68.6 70.4 68.6 0.0 0.0 No

– Between Fairfax Ave. and Ogden Dr.

Residential 72.0 70.3 72.0 70.4 0.0 0.1 No

– Between Ogden Dr. and Curson Ave.

Residential 72.0 70.2 72.0 70.2 0.0 0.0 No

– East of Curson Ave. Residential 72.6 70.5 72.6 70.5 0.0 0.0 No

Wilshire Boulevard

– West of Fairfax Avenue Commercial 74.0 72.3 74.0 72.3 0.0 0.0 No


Museum 73.2 72.0 73.2 72.0 0.0 0.0 No


Museum 73.0 72.0 73.0 72.0 0.0 0.0 No

– East of Curson Ave. Commercial 73.3 72.4 73.3 72.4 0.0 0.0 No

8th Street


– Between Fairfax Ave. and Curson Ave.

Residential 69.9 66.2 69.9 66.3 0.0 0.1 No


a Detailed calculation worksheets are included in Appendix K.

Source: AES, 2017.

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Table IV.I-23 Roadway Traffic Noise Impacts—Existing Plus Project




Existing Existing Plus Project Traffic Noise Levels



Fairfax Avenue



Residential 72.9 72.6 72.9 72.6 0.0 0.0 No


Ogden Drive


Spaulding Avenue


Curson Avenue


Residential 70.3 66.3 70.3 66.3 0.0 0.0 No


Hauser Boulevard



Cochran Avenue



IV.I Noise

Table IV.I-23 (Continued) Roadway Traffic Noise Impacts—Existing Plus Project


Page IV.I-46




Existing Existing Plus Project Traffic Noise Levels



6th Street



Residential 71.6 69.9 71.7 70.0 0.1 0.1 No


Residential 71.7 69.8 71.7 69.9 0.0 0.1 No


Wilshire Boulevard



Museum 72.2 71.0 72.2 71.1 0.0 0.1 No


Museum 71.9 71.0 71.9 71.0 0.0 0.0 No


8th Street



Residential 69.5 65.9 69.6 66.0 0.1 0.1 No



Source: AES, 2017.

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Table IV.I-24 Composite Noise Impacts

Receptor Location

Existing Ambient

Noise Levels, CNEL (dBA)

Calculated Project-Related Noise Sources, CNEL (dBA) Project Composite

Noise Levels,

CNEL (dBA)

Ambient Plus Project

Noise Levels,

CNEL (dBA)

Increase in Noise

Levels Due to Project,

CNEL (dBA)

Significant Impact? Traffic

Mechanical Equipment Parking

Loading/ Trash

Compactor Outdoor Spaces

Special Events

R1 60.5 41.8 42.0 40.6 51.4 49.0 51.1 55.9 61.8 1.3 No

R2 59.4 43.7 38.5 32.4 40.3 51.5 45.7 53.4 60.4 1.0 No

R3 66.6 36.0 37.5 27.5 29.3 38.9 60.0 60.1 67.5 0.9 No

R4 71.4 43.6 40.8 33.5 41.1 42.7 69.6 69.6 73.6 2.2 No

R5 62.3 58.0 40.8 55.7 37.8 35.9 61.3 63.8 66.1 3.8 No

R6 61.4 41.8 33.9 36.1 43.9 51.7 44.1 53.4 62.0 0.6 No

Source: AES, 2017.

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Page IV.I-48

4. Cumulative Impacts

The Project, together with the related projects and future growth, could contribute to cumulative noise impacts. The potential for cumulative noise impacts to occur is specific to the distance between each related project and their stationary noise sources, as well as the cumulative traffic that these projects would add to the surrounding roadway network.

a. Construction Noise and Vibration

(1) On-Site Construction Noise

As indicated in Section III, Environmental Setting, of this Draft EIR, a total of 34 related projects have been identified in the vicinity of the Project Site. Noise from construction of development projects is typically localized and has the potential to affect areas within 500 feet from the construction site. Thus, noise from construction activities for two projects within 1,000 feet of each other can contribute to a cumulative noise impact for receptors located midway between the two construction sites. While the majority of the related projects are located a substantial distance (greater than 1,000 feet) from the Project Site, the following three related projects are within 1,000 feet of the Project Site:

Related Project No. 20, a proposed 254,000 square foot office development is located at 5757 Wilshire Boulevard, approximately 610 feet east of the Project Site. There are noise sensitive receptors located along Curson Avenue in the vicinity of the Project Site and Related Project No. 20 (represented by receptor location R3). As analyzed above, the estimated Project-related construction noise levels at receptor R3 would be 60.3 dBA, which would be 3.7 dBA below the existing ambient noise level. Therefore, the Project would not contribute to cumulative construction-related noise impacts at receptor location R3.

Related Project No. 23, the Academy Museum of Motion Pictures (Academy Museum) located at 6067 Wilshire Boulevard (i.e., LACMA West), approximately 300 feet from the Project’s Ogden Lot. There are existing noise-sensitive receptors located in the vicinity of the Project Site and this related project, including the residential uses along 6th Street, Orange Grove Avenue and Ogden Drive. This related project is under construction and is anticipated to be completed in 2019, at or just after the start of the Project construction. Thus, there is a potential for some more limited overlap of construction activities between Related Project No. 23 and the Project. The construction-related noise from Related Project No. 23 would be shielded to the residential uses along Orange Grove Avenue and Ogden Drive by the existing building structures along Wilshire Boulevard. The construction-related noise during the final phases of

IV.I Noise


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Related Project No. 23 would include interior improvements that would generate approximately 57.0 dBA at the residential uses along 6th Street.32 The estimated maximum construction-related noise from the Project at the residential uses along 6th Street (receptor R4) is 69.6 dBA. The cumulative construction noise from the Project and Related Project No. 23 at this location would be approximately 69.8 dBA, which would be below the significance threshold of 69.9 dBA. Therefore, the Project and Related Project No. 23 would not result in cumulative construction-related noise impacts.

Related Project No. 30 (Petersen Automotive Museum) includes 15,000 square feet of new display space. There are noise sensitive receptors located along Orange Grove Avenue and Ogden Drive between the Project Site and the Related Project No. 20 (represented by receptor location R5). However, this related project construction has been completed. Therefore, this related project would not contribute to cumulative construction-related noise impacts.

Metro Purple Line Extension (Wilshire/Fairfax Station). The Los Angeles County Metropolitan Transportation Authority (“Metro” or “LACMTA”) is currently constructing the Purple Line Extension Project, which includes a station entrance (Wilshire/Fairfax Station) to be located at the southeast corner of Wilshire Boulevard and Orange Grove Avenue. The area south of Wilshire Boulevard, between Orange Grove Avenue and Ogden Drive, is currently being used for construction staging and as a laydown area for Metro’s Purple Line Extension Project, with construction of the actual station scheduled closer to the 2023 completion date. In addition, Metro would include roadway reconstruction in the vicinity of the Project Site. There are noise sensitive uses located adjacent to the Metro construction site along Ogden Drive (represented by receptor R5). As analyzed above, the estimated Project-related construction noise levels at receptor R5 would be up to 70.1 dBA, which would exceed the significance threshold of 65.0 dBA. Thus, cumulative construction noise impacts associated with the Project and the Metro Purple Line Extension Project would be considered significant.

Construction-related noise levels from the related projects would be intermittent and temporary, and it is anticipated that, as with the Project, the related projects would comply with the construction hours and other relevant provisions set forth in the LAMC. Noise associated with cumulative construction activities would be reduced to the degree reasonably and technically feasible through proposed mitigation measures for each individual related project and compliance with locally adopted and enforced noise ordinances. However, based on the above, potential cumulative noise impacts at the nearby sensitive uses located in proximity to the Project Site would be significant. 32 City of Los Angeles, Academy Museum of Motion Pictures Project Draft EIR, August 2014, Section 4.H

Noise.

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(2) Off-Site Construction Noise

In addition to the cumulative impacts of on-site construction activities, off-site construction haul trucks would have a potential to result in cumulative impacts if the trucks for the related projects and the Project were to utilize the same haul routes. Specifically, a significant cumulative impact would occur if the cumulative construction truck volumes from the Project and the related projects were to result in noise levels that exceed the existing daytime ambient noise level along the anticipated haul routes. As discussed above, the primary haul routes include Wilshire Boulevard and La Brea Avenue. As analyzed above, the estimated off-site noise levels from Project construction trucks would be below ambient noise levels along Wilshire Boulevard and La Brea Avenue by a minimum of 4.7 dBA during the peak period (grading/excavation). In order for the construction related noise to exceed the ambient noise levels, the truck trips would need to be increased by an approximately factor of 3 (i.e., increased from 42 trips per hour to 130 trips per hour). The estimated noise levels with 130 truck trips per hour would be approximately 72.4 dBA, which exceeds the significance threshold along Wilshire Boulevard. Since the Project would generate up to 42 truck trips during peak construction activities, it is conservatively assumed that truck traffic related to construction of the Project and other related projects would cumulatively add up to 130 or more hourly truck trips, along Wilshire Boulevard and La Brea Avenue. As such, cumulative noise impacts from off-site construction would be cumulatively considerable and would be significant.

(3) On-Site Construction Vibration

As previously discussed, ground-borne vibration decreases rapidly with distance. Potential vibration impacts due to construction activities are generally limited to buildings/structures that are located in close proximity of the construction site (i.e., within 50 feet). As indicated above, the nearest related project is approximately 300 feet from the Project Site. In addition, construction of the Ogden Parking Structure would occur after the completion of Metro’s Wilshire/Fairfax Station. Therefore, due to the rapid attenuation characteristics of ground-borne vibration, there is no potential for a cumulative construction impact with respect to ground-borne vibration.

(4) Off-Site Construction Vibration

As analyzed above, the estimated vibration levels generated along the haul routes (Wilshire Boulevard and La Brea Avenue) would be 0.016 PPV, which would be well below the most stringent building damage threshold of 0.12 PPV. Trucks from the related projects are expected to generate similar ground-borne vibration levels along the haul routes as the Project. Therefore, the vibration levels generated from off-site construction trucks associated with the Project and other related projects along the anticipated haul routes would be well below the most stringent building damage threshold of 0.12 PPV for

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buildings extremely susceptible to vibration. Therefore, potential cumulative vibration impacts with respect to building damage from off-site construction would be less than significant.

As analyzed above, the estimated vibration levels from Project-related construction trucks traveling along the anticipated haul routes would be approximately 72 VdB, which would be below the 80 VdB significant with respect to human annoyance. It is anticipated that construction trucks from the related projects would generate similar vibration levels along the anticipated haul routes. Therefore, to the extent that other related projects use the same haul routes as the Project, potential cumulative human annoyance impacts associated with temporary and intermittent vibration from haul trucks traveling along the anticipated haul routes would be less than significant.

b. Long-Term Operations

The Project Site and surrounding area have been developed with uses that have previously generated, and will continue to generate, noise from a number of community noise sources, including mechanical equipment (e.g., HVAC systems), outdoor activity areas, and vehicle travel. Similar to the Project, each of the related projects that has been identified in the vicinity of the Project Site would also generate stationary-source and mobile-source noise due to ongoing day-to-day operations. All related projects are of a residential, retail, commercial, or institutional nature, and these uses are not typically associated with excessive exterior noise levels. However, each project would produce traffic volumes that are capable of generating roadway noise impacts. The potential cumulative noise impacts associated with on-site and off-site noise sources are addressed below.

(1) On-Site Stationary Noise Sources

Due to provisions set forth in the LAMC that limit stationary source noise from items such as roof-top mechanical equipment, noise levels from these sources would be less than significant at the property line for each related project. In addition, with implementation of regulatory requirements and the proposed project design features presented in this section, noise impacts associated with operations within the Project Site would be less than significant. Based on the distance of the related projects from the Project Site and the noise levels associated with the Project, cumulative stationary source noise impacts associated with operation of the Project and related projects would be less than significant.

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(2) Off-Site Mobile Noise Sources

The Project and other related development in the area would produce traffic volumes (off-site mobile sources) that would generate roadway noise. Cumulative noise impacts due to off-site traffic were analyzed by comparing the projected increase in traffic noise levels from Existing Conditions to Future Cumulative Plus Project Conditions to the applicable significance criteria. Future Cumulative Conditions include traffic volumes from future ambient growth, related projects, and the Project. The calculated traffic noise levels under Existing Conditions and Future Cumulative Plus Project Conditions are presented in Table IV.I-25 on page IV.I-53. As shown therein, cumulative traffic volumes would result in a maximum increase of 1.6 dBA along Ogden Drive during a typical weekday and 2.4 dBA during a typical weekend. At all other analyzed roadway segments, the increase in cumulative traffic noise would be lower. Thus, the cumulative traffic noise increase would be below the 3 dBA significance threshold. Therefore, cumulative noise impacts due to off-site mobile noise sources associated with the Project, future growth, and related projects would be less than significant.

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Table IV.I-25 Cumulative Roadway Traffic Noise Impacts




Existing Conditions Cumulative Plus Project Traffic Noise Levels

Increase


Fairfax Avenue



Residential 72.9 72.6 73.5 73.1 0.6 0.5 No


Ogden Drive


Spaulding Avenue


Curson Avenue


Residential 70.3 66.3 70.7 67.0 0.4 0.7 No


Hauser Boulevard



Cochran Avenue



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Table IV.I-25 (Continued) Error! Reference source not found.


Page IV.I-54




Existing Conditions Cumulative Plus Project Traffic Noise Levels

Increase


6th Street



Residential 71.6 69.9 72.0 70.4 0.4 0.5 No


Residential 71.7 69.8 72.0 70.2 0.3 0.4 No


Wilshire Boulevard



Museum 72.2 71.0 73.2 72.0 1.0 1.0 No


Museum 71.9 71.0 73.0 72.0 1.1 1.0 No


8th Street



Residential 69.5 65.9 69.9 66.3 0.4 0.4 No



Source: AES, 2017.

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5. Mitigation Measures

a. Construction

As analyzed above, construction of the Project would have the potential to result in significant noise impacts at the off-site sensitive receptor locations from on-site construction activities. Thus, the following measures are included to minimize construction-related noise impacts:

Mitigation Measure I-1: A temporary and impermeable sound barrier shall be erected at the following locations. The temporary sound barrier shall have a minimum STC 25 rating.

Along the southern property line of the Spaulding Lot between the construction areas and existing multi-family residential use on Spaulding Avenue. The temporary sound barrier shall be 16 feet tall and designed to provide a minimum 15-dBA noise reduction at ground level of the adjacent noise-sensitive receptors R1 and R6.

Along the eastern property line of the Spaulding Lot between the construction areas and existing multi-family residential use on Stanley Avenue. The temporary sound barrier shall be 18 feet tall and designed to provide a 16-dBA noise reduction at ground level of the residential use along the east side of Stanley Avenue (receptor R2).

The Applicant is proposing to maintain the existing Metro’s noise barrier along the southern property line of the Ogden Lot between the construction areas and existing multi-family residential use on Ogden Drive, during the Ogden Parking Structure construction. In the event Metro removes the existing noise barrier, a temporary sound barrier of similar height shall be provided and designed to provide a minimum 15-dBA noise reduction at the ground level of the adjacent noise-sensitive receptor R5.

Additionally, as analyzed above, Project-related on-site construction activities would have the potential to result in significant vibration impacts with respect to building damage at the multi-family residential building adjacent to the Ogden Lot. Thus, the following mitigation measure is included to minimize construction-related vibration impacts:

Mitigation Measure I-2: Prior to start of construction for the Ogden Parking Structure, the Applicant shall retain the services of a structural engineer or a qualified professional to visit the existing multi-family building structure on Ogden Drive adjacent to the Ogden Lot to

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inspect and document the apparent physical condition of the buildings’ readily-visible features.

The Applicant shall retain the services of a qualified acoustical engineer to review proposed construction equipment and develop and implement a vibration monitoring system capable of documenting the construction-related ground vibration levels at the off-site multi-family residential building during the site demolition and excavation for the Ogden Parking Structure, where heavy construction (e.g., large bulldozer and drill rig) would be operating within 12 feet of the multi-family residential building adjacent to the south. In the event that site access to the adjacent off-site multi-family residential building is not available for the vibration monitoring, vibration monitoring shall be conducted at a distance of 10 feet from the construction equipment (representative of the distance between the off-site building and the construction equipment). Vibration monitoring will include the following:

a) The vibration monitoring system shall measure and continuously store the peak particle velocity (PPV) in inch/second. Vibration data shall be stored on a one-second interval. The system shall also be programmed for two preset velocity levels: a warning level of 0.2 inch/second (PPV) and a regulatory level of 0.3 inch/second (PPV) at the off-site building. The system shall also provide real-time alert when the vibration levels exceed the preset level.

b) In the event the warning level of 0.2 inch/second (PPV) is triggered, the contractor shall identify the source of vibration generation and provide feasible steps to reduce the vibration level, including, but not limited to, halting/staggering concurrent activities and utilizing lower vibratory techniques.

c) In the event the regulatory level 0.3 inch/second (PPV) is triggered, the contractor shall halt the construction activities in the vicinity of the building and have the structural engineer or a qualified professional visually inspect the building for any damage. Results of the inspection must be logged. The contractor shall identify the source of vibration generation and provide feasible steps to reduce the vibration level. Construction activities may then restart.

b. Operation

As discussed above, operation of the Project would not result in a significant impact. Therefore, no mitigation measure is required.

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6. Level of Significance After Mitigation

a. Construction Noise

(1) On-Site Construction Noise

Implementation of Mitigation Measure I-1 provided above would reduce the Project’s and cumulative construction noise levels to the extent feasible. Specifically, implementation of Mitigation Measure I-1 (installation of temporary sound barriers) would reduce the noise generated by on-site construction activities at the off-site sensitive uses to by up to 15 dBA at receptors R1 and R6 and by up to 16 dBA at receptor R2. The construction noise impacts at receptor R2 would be reduced to a less than significant level. However, construction-related noise levels at receptor locations R1, R5, and R6 would still exceed the Project significance threshold. As described above, the maximum noise reduction that a noise barrier can provide would be approximately 20 dBA. For receptors R1 and R6, the noise analysis assumed a 5 dBA noise reduction provided by existing block wall along the Project’s south property line. Therefore, the maximum additional noise reduction provided by the temporary sound barrier would be 15 dBA, as specified by Mitigation Measure I-1. A 15 dBA noise reduction is substantial reduction. However, there are no other feasible mitigation measures that could be implemented to further reduce the temporary noise impacts from on-site construction activities to a less-than-significant level. Therefore, construction noise impacts associated with on-site noise sources would remain significant and unavoidable.

As analyzed above, cumulative construction noise impacts associated with on-site noise sources would be significant.

(2) Off-Site Construction Noise

Project-level noise impacts from off-site construction would be less than significant. However, cumulative noise due to construction truck traffic from the Project and other related projects would likely exceed the ambient noise levels along the haul routes. As such, cumulative noise impacts from off-site construction would be significant and unavoidable.

b. Construction Vibration

(1) On-Site Construction Vibration

Implementation of Mitigation Measure I-2 would reduce vibration impacts from on-site construction with respect to building damage at the off-site building adjacent to the Project Site (Ogden Lot) to a less-than-significant level. Specifically, with implementation

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of Mitigation Measure I-2, vibration levels at the affected building would be below the 0.3 PPV threshold. Therefore, Project-level vibration impacts from on-site construction activities with respect to building damage would be less than significant.

Additional mitigation measures considered to reduce vibration impacts from on-site construction activities with respect to human annoyance included the installation of a wave barrier, which is typically a trench or a thin wall made of sheet piles installed in the ground (essentially a subterranean sound barrier to reduce noise). However, wave barriers must be very deep and long to be effective and are not considered cost effective for temporary applications, such as construction.33 In addition, constructing a wave barrier to reduce the Project’s construction-related vibration impacts would, in and of itself, generate ground-borne vibration from the excavation equipment. Due to the nature of construction activities (i.e., required construction equipment and relative distance to the receptor) there is no flexibility to maximize the distance between the construction equipment and the receptor locations. Thus, it was concluded that there are no feasible mitigation measures that could be implemented to reduce the temporary vibration impacts from on-site construction associated with human annoyance to a less-than-significant level. Therefore, Project-level vibration impacts from on-site construction activities with respect to human annoyance would remain significant and unavoidable.

Cumulative vibration impacts with respect to building damage and human annoyance from on-site construction activities would be less than significant.

(2) Off-Site Construction Vibration

Vibration levels generated by construction-related trucks (i.e., haul, delivery, and concrete trucks) along the anticipated haul routes (i.e., Wilshire Boulevard and La Brea Avenue) would be well below the significance threshold for building damage. Therefore, both Project and cumulative vibration impacts with respect to building damage would be less than significant.

Vibration levels from construction-related trucks would be below the significance threshold for human annoyance at the vibration sensitive receptors along anticipated haul routes. Therefore, both Project and cumulative vibration impacts from off-site construction with respect to human annoyance would be less than significant.

33 Caltrans, Transportation- and Construction-Induced Vibration Guidance Manual, June 2004.

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c. Operational Noise

Project-level and cumulative impacts with regard to operational noise would be less than significant.

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