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Wilshire Grand Redevelopment Project IV.C. Noise Draft Environmental Impact Report Page IV.C-1

IV. ENVIRONMENTAL IMPACT ANALYSIS C. NOISE

This Section evaluates the potential for noise and groundborne vibration impacts resulting from implementation of the Project. This includes the potential for the Project to result in impacts associated with a substantial temporary and/or permanent increase in ambient noise levels in the vicinity of the Project Site; exposure of people in the vicinity of the Project Site to excessive noise levels, groundborne vibration, or groundborne noise levels; and whether this exposure is in excess of established standards. Finally, mitigation measures intended to reduce impacts to noise and vibration are proposed, where appropriate, to avoid or reduce significant impacts of the Project.

Data used to prepare this analysis were obtained from the City of Los Angeles General Plan Noise Element, the City of Los Angeles Municipal Code (LAMC), and by measuring and modeling existing and future noise levels at the Project Site and the surrounding land uses. Traffic information contained in the transportation study prepared for the Project was used to prepare the noise modeling for vehicular sources (refer to Appendix IV.B).

The information in this Section is summarized from the following reports, which can be found in Appendix IV.C to this EIR:

• Noise Impact Study, Wilshire Grand Redevelopment Project, prepared by Acoustical Engineering Services, May 2010 (Appendix IV.C.1)

• Helicopter Noise Technical Memorandum for the Wilshire Grand Redevelopment Project, prepared by Heliport Consultants, May 2010 (Appendix IV.C.2)

1. ENVIRONMENTAL SETTING

a. Fundamentals of Sound and Environmental Noise

i. Outdoor Sound Propagation

ii. Environmental Noise Descriptors

b. Fundamentals of Environmental Groundborne Vibration

c. Regulatory Framework

i. Federal

1. Noise Standards

(a) U.S. Department of Housing and Urban Development

(b) Federal Aviation Administration

(i) Land Use Compatibility

City of Los Angeles July 2010


(ii) Sleep Disturbance

2. Vibration Standards

ii. State of California

1. Noise Standards


iii. City of Los Angeles

1. 1997 Los Angeles Unified School District Noise Guidelines

2. City of Los Angeles Noise Element

3. City of Los Angeles Noise Regulation

4. City of Los Angeles Noise Compatibility Guidelines

d. Existing Noise Conditions

i. Sensitive Receptors

ii. Existing Ambient Noise Levels

iii. Traffic Noise Levels

e. Existing Groundborne Vibration

2. ENVIRONMENTAL IMPACTS

a. Thresholds of Significance

i. Construction Noise

ii. Operational Noise

1. Traffic Noise and On-Site Noise Sources

2. Helicopter Noise

(a) Land Use Compatibility

(b) Sleep Disturbance

3. School Uses



4. Summary of Operational Noise Significance Thresholds

iii. Groundborne Vibration (Construction)

b. Methodology

i. Ambient Noise Measurement

ii. Construction Noise

iii. Operational Noise

1. Off-Site Roadway Noise

2. On-Site Stationary Noise Sources

3. Helistop Operation

iv. Groundborne Vibration (Construction)

c. Project Design Features

i. Construction

ii. Operation

d. Project Impacts

i. Construction Noise and Vibration Impacts

1. Construction Noise

2. Off-Site Noise Sources (Construction Trucks)

3. Groundborne Vibration


1. On-Site Noise Sources Noise

(a) Building Mechanical Equipment

(b) Parking Facility

(c) Loading and Trash/Recycling Areas

(d) Outdoor Services



2. Helistop


(b) Sleep Disturbance

3. Off-Site Traffic (Mobile Sources)

4. Alternative Traffic Impact

5. Composite Noise Level Impacts from Project Operations

iii. Site Compatibility for New Buildings

e. Land Use Equivalency Program

f. Design Flexibility Program

3. CUMULATIVE IMPACTS

a. Construction Noise

b. Construction Vibration

c. Operational Noise

4. PROJECT DESIGN FEATURES AND MITIGATION MEASURES

a. Construction

b. Operation

c. Cumulative Construction

5. LEVEL OF SIGNIFICANCE AFTER MITIGATION


b. Operational Noise

c. Groundborne Vibration



1. ENVIRONMENTAL SETTING

a. Fundamentals of Sound and Environmental Noise

Sound is technically described in terms of amplitude (loudness) and frequency (pitch). The standard unit of sound amplitude measurement is the decibel (dB). The decibel scale is a logarithmic scale that describes the physical intensity of the pressure vibrations that make up any sound. The pitch of the sound is related to the frequency of the pressure vibration. Since the human ear is not equally sensitive to a given sound level at all frequencies, a special frequency-dependent rating scale has been devised to relate noise to human sensitivity. The A-weighted decibel scale (dBA) provides this compensation by filtering the noise signal in a manner that corresponds to the way a human ear perceives sound.

Noise, on the other hand, is typically defined as unwanted sound. A typical noise environment consists of a base of steady ambient noise that is the sum of many distant and indistinguishable noise sources. Superimposed on this background noise is the sound from individual local sources. These can vary from an occasional aircraft or train passing by to virtually continuous noise from, for example, traffic on a major highway. Table IV.C-1 (Representative Environmental Noise Levels) illustrates representative noise levels in the environment.

People judge the relative magnitude of sound sensation by 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 an increase of 10 dB is recognized as “twice as loud.”1 Generally speaking, the human ear is physiologically incapable of discerning a difference in the noise environment for a change of less than 3 dBA in a normal hearing environment (i.e., not in a laboratory or diagnostic setting).

i. Outdoor Sound Propagation

In an outdoor environment, sound levels attenuate (reduce) through the air as a function of distance. Such attenuation is commonly referred to as “distance loss” or “geometric spreading,” and is based on the noise source configuration, point source, or line source. For a point source, such as a piece of mechanical/electrical/construction equipment (e.g., air conditioner, electrical transformer, or bull dozer) the rate of sound attenuation is 6 dB per doubling of distance from the noise source. For example, an outdoor condenser fan that generates a sound level of 60 dBA at a distance of five feet would attenuate to 54 dBA at a distance of 10 feet. For a line source, such as a constant flow of traffic on a roadway, the rate of sound attenuation is 3 dB per doubling of distance.2

In addition, structures (e.g., buildings and solid walls) and natural topography (e.g., hills) that obstruct the line-of-sight between a noise source and a receptor further reduce the noise level if the receptor is located

1 Engineering Noise Control, Bies & Hansen, 1988. 2 Caltrans, Technical Noise Supplement, 1998.



Table IV.C-1 Representative Environmental Noise Levels

Common Outdoor Activities Noise Level (dBA) Common Indoor Activities —110— Rock Band

Jet Fly-over at 100 feet —100—

Gas Lawnmower at 3 feet —90—

Noisy Urban Area during Daytime Food Blender at 3 feet Diesel Truck going 50 mph at 50 feet —80— Garbage Disposal at 3 feet

Gas Lawnmower 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 Area during Daytime —50— Dishwasher in Next Room

Quiet Urban Area during Nighttime —40— Theater, Large Conference Room (background)

Quiet Suburban Area during Nighttime —30— Library

Quiet Rural Area during Nighttime Bedroom at Night, Concert Hall (background) —20— Broadcast/Recording Studio —10—

Lowest Threshold of Human Hearing —0— Lowest Threshold of Human Hearing Source: California Department of Transportation, Technical Noise Supplement: A Technical Supplement to the Traffic Noise Analysis Protocol, October 1998, page 18.

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., line-of-sight is not fully blocked), some barrier insertion loss would still occur, although 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 noise source and receiver) to an upper range of 20 dBA with a more substantial barrier.3

ii. 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 on people is

3 Ibid.



largely dependent on the total acoustical energy content of the noise, as well as the time of day when the noise occurs. Those that are applicable to this analysis are as follows:

• Equivalent Sound Level (Leq) - An Leq is the average acoustic energy content of noise for a stated period of time. Thus, the Leq of a time-varying noise and that of a steady noise are the same if they deliver the same acoustic energy to the ear during exposure. Leq for one-hour periods, during the daytime or nighttime hours, and 24 hours are commonly used in environmental noise assessments. Leq can be measured for any time period, but is typically measured for an increment of no less than 15 minutes for environmental studies. For evaluating community impacts, this rating scale does not vary, regardless of whether the noise occurs during the day or the night.

• Maximum Sound Level (Lmax) – The maximum instantaneous noise level measured during a given period of time. Lmax is a measure of highest sound level at a particular point in time. Lmax is used to evaluate noise effects from helicopter operations on noise sensitive land uses such as schools.

• Sound Exposure Level (SEL) – SEL is primarily used to evaluate noise effects from the operation of a helistop (i.e., helicopter flight noise) on noise sensitive land uses such as residential. SEL is an energy-based sum of the noise experienced during a single noise event, normalized to one second duration. For a single helicopter flight to the facility (i.e., one arrival and departure), the timeframe of the noise event reflected in the SEL encompasses the approach, landing, idling, takeoff and departure activities of the aircraft. SEL takes into account both intensity and duration of the sound generated during the event. Typically, SEL for aircraft noise is 10 dBA higher than Lmax.

• Community Noise Equivalent Level (CNEL) - CNEL is the time average of all A-weighted sound levels for a 24-hour day period with a 10 dBA adjustment (upward) added to the sound levels which occur in the nighttime hours (10:00 p.m. to 7:00 a.m.) and a 5 dBA adjustment (upward) added to the sound levels which occur in the evening hours (7:00 p.m. to 10:00 p.m.). These penalties attempt to account for increased human sensitivity to noise during the quieter nighttime 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 its 2006 Los Angeles CEQA Thresholds Guide (L.A. CEQA Thresholds Guide).4,5

• Day-Night Average Level (Ldn or DNL). Ldn, like CNEL, is the weighted 24-hour average noise level in an environment which accounts for peoples increased annoyance to noise occurring in the nighttime hours. It is the average equivalent A-weighted sound level during a 24-hour day,

4 State of California, General Plan Guidelines, 2003. 5 The L.A. CEQA Thresholds Guide is available at

http://www.lacity.org/ead/environmentla/programs/thresholdsguide.htm.



calculated after adding 10 decibels to sound levels which occur in the night after 10:00 p.m. and before 7:00 a.m. Typically, Ldn levels are within 1 dBA of CNEL levels.

b. Fundamentals of Environmental Groundborne 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, while RMS is defined as the square-root of the average of the squared amplitude of the signal. PPV is typically used for evaluating potential building damage, whereas RMS is typically more suitable for evaluating human response to groundborne vibration.6 The RMS vibration velocity level can be presented in inches per second or in VdB (a decibel unit referenced to 1 micro-inch per second)7. Commonly, groundborne vibration generated by man-made activities (i.e., road traffic, construction operations) attenuates rapidly with distance from the source of the vibration.

c. Regulatory Framework

i. Federal

1. Noise Standards

(a) U.S. Department of Housing and Urban Development

The U.S. Department of Housing and Urban Development (HUD) provides noise standards for residential units developed under HUD funding. The HUD noise standards are included in Title 24 Part 51B of the Code of Federal Regulations (CFR). HUD has set a goal of 65 dBA Ldn (65 dBA CNEL for projects in California) as “acceptable” exterior noise standard for residential development and 45 dBA Ldn (45 dBA CNEL for projects in California) as a desirable maximum interior noise standard for residential units. Although HUD noise standards are not required for non-federally funded projects, the standards are consistent with other federal agencies, such as the Federal Aviation Administration (FAA), as well as the State of California and City of Los Angeles noise standards and building construction codes.

(b) Federal Aviation Administration

The FAA establishes the aircraft noise analysis methodology and significance thresholds that are applicable to federally funded projects that have an aviation noise component. The guidelines contained in FAA documents are considered the industry standard used by the State of California and City of Los Angeles noise standards and building construction codes. These standards address potential aircraft noise

6 Federal Transit Administration (FTA), “Transit Noise and Vibration Impact Assessment,” May 2006, Section

7.1.2. 7 VdB (velocity level in decibel) = 20 x Log (V / Vref), where V is the RMS velocity amplitude in inch per second

and Vref is the reference velocity amplitude of 1x10-6 inch per second (1 micro-inch per second)



in two different ways. First, land use compatibility is addressed through consideration of changes in the 24-hour noise environment, measured in CNEL. Second, the potential for sleep disturbance is assessed through application of the Sound Exposure Level (SEL) associated with individual helicopter events.

(i) Land Use Compatibility

CFR Title 14 Part 150, Airport Noise Compatibility Planning, provides guidelines for land use compatibility around airports and states that, in general, residential uses are not compatible within the 65 dBA Ldn contour or above and that all types of land uses are compatible in areas below 65 dBA Ldn (65 dBA CNEL for projects in California). In addition, the FAA's Order 1050.1E, Environmental Impacts: Policies and Procedures, as well as in the L.A. CEQA Thresholds Guide, establishes a screening threshold of a 1.5 dBA Ldn (or 1.5 dBA CNEL for projects in California) increase in noise in any sensitive area located within the 65 dBA Ldn (or 65 dBA CNEL for projects in California) contour. In practice, it has been found that unless a proposed airport project will cause at least a 1.5 dB increase within the 65 dB CNEL or greater area, a 3 dB or greater (i.e., audible) increase in the 60-65 dB CNEL area will not occur.8

(ii) Sleep Disturbance

In addition to changes in the 24-hour average noise level, aviation operations have the potential to affect individuals through the disturbance of sleep. The effects of single event aircraft noise (SEL) are utilized to assess the effects of aviation noise on sleep. Research has been done which examines the correlation between single event noise levels and the prediction of “annoyance” due to sleep or speech interference. In 1992, the Federal Interagency Committee on Noise (FICON) recommended an interim dose-response curve (“the 1992 FICON interim curve”) to predict the percent of the exposed population expected to be awakened as a function of the SEL level. Much of the research reflected in the 1992 FICON interim curve was based on studies conducted in the laboratory. After 1992, substantial field research in the area of sleep disturbance was completed, using a variety of test methods, and in a number of locations. The successor to FICON, the Federal Interagency Committee on Aviation Noise (FICAN), analyzed several sleep studies regarding the relationship between SEL and sleep disturbance as measured by number of awakenings.9

The post-1992 research showed a consistent pattern, with considerably less of the exposed population expected to be behaviorally awakened than had been shown with laboratory studies. Based on the research available through 1997, FICAN developed a curve (the “FICAN 1997 curve”) that represents a conservative dose-response relationship for aircraft noise and sleep disturbance. This curve predicts the maximum percent of the exposed population that would be expected to be behaviorally awakened under different interior SEL levels. For instance, according to the FICAN 1997 curve, an interior single event

8 Federal Agency Review of Selected Airport Noise Analysis Issues, Federal Interagency Committee on Noise,

August 1992. 9 Effects of Aviation Noise on Awakenings from Sleep, Federal Interagency Committee on Aviation Noise, June

1997.



noise level of approximately 81 dBA (interior SEL) would be expected to result in the awakening of about 10 percent of the affected population.10

With respect to classroom disruption, a maximum interior noise level of 55 dBA (Lmax) for classrooms is recommended. The classroom interior noise standard of 55dBA (Lmax) was used in the Los Angeles International Airport, South Airfield Improvement Project EIR, which was based on the review of the EPA 1974 document “Levels Document”, the ANSI standard S12.60, and the FICON 1992 report.11, 12, 13,

14


There are no adopted federal policies or standards for groundborne vibration. In most circumstances, common vibrations related to roadway traffic and construction activities pose no threat to buildings or structures. The following guidelines from federal and state agencies are utilized in assessing potential groundborne vibration impacts due to Project construction activities.

The Federal Transit Administration (FTA) has published a technical manual titled Transit Noise and Vibration Impacts Assessment that provides groundborne vibration impact criteria with respect to building damage during construction activities.15 With respect to potential building damage, the FTA provides guidelines for evaluating potential groundborne vibration damage applicable to various building categories. Table IV.C-2 (Construction Vibration Damage Criteria) provides the FTA vibration criteria applicable to construction activities. According to FTA guidelines, a vibration damage criterion of 0.20 inch per second PPV should be considered for non-engineered timber and masonry buildings. Furthermore, structures or buildings constructed of reinforced-concrete, steel, or timber, have vibration damage criteria of 0.50 inch per second pursuant to the FTA guidelines. Buildings of a historical nature have lower vibration tolerances, PPV of 0.12 inch per second, pursuant to FTA Vibration Damage Criteria.

10 Percent of Awakening = 0.0087 x (SEL – 30)^1.79, from FICAN, Effects of Aviation Noise on Awakening from

Sleep, June 1997. 11 Los Angeles International Airport, South Airfield Improvement Project EIR, Appendix M, August 2005. 12 Environmental Protection Agency (EPA), Information on Levels of Environmental Noise Requisite to Protect

Public Health and Welfare with an Adequate Margin of Safety, EPA/ONAC 550/9-74-004, March 1974. 13 ANSI Standard S12.60-2002 (R2009), Acoustical Performance Criteria, Design Requirements, and Guidelines for

Schools. 14 Federal Interagency Committee on Noise (FICON), Federal Agency Review of Selected Airport Noise Analysis

Issues, August 1992. 15 Transit Noise and Vibration Impact Assessment, Federal Transit Administration, May 2006.



Table IV.C-2 Construction Vibration Damage Criteria

Building Category PPV

(inches/second) RMS in Decibels

(VdB) I. Reinforced-concrete, steel or timber (no plaster) 0.5 102 II. Engineered concrete and masonry (no plaster) 0.3 98 III. Non-engineered timber and masonry buildings 0.2 94 IV. Buildings extremely susceptible to vibration damage 0.12 90 PPV = peak particle velocity RMS = root-mean square Source: Federal Transit Administration, Transit Noise and Vibration Impact Assessment, May 2006, Table 12-3.

In addition to the FTA Construction Vibration Damage Criteria listed in Table IV.C-2, the FTA guidance manual also provides a vibration perception threshold for humans related to ground vibration. According to FTA guidelines, the human “threshold of perception” related to ground vibration is approximately 65 VdB (RMS).16 Although the perceptibility threshold is about 65 VdB, human response to vibration is not usually significant unless the vibration exceeds 70 VdB. Table IV.C-3 provides the human response to different groundborne vibration levels per the FTA guidance manual. As indicated in IV.C-3, ground vibration level of 78 VdB would be barely perceptible and up to 90 VdB would be distinctly perceptible.

Table IV.C-3 FTA Human Response to Groundborne Vibration Criteria

Vibration Velocity Level,

VdB Human Response 65 Approximate threshold of perception for many humans 72 Vibration not feelable 75 Approximate dividing line between barely perceptible and distinctly perceptible 78 Barely feelable vibration 84 Feelable vibration 90 Distinctly feelable vibration

Source: “Transit Noise and Vibration Impact Assessment” (FTA, 2006), Table 7-1 and Table 8-3.

ii. State of California

1. Noise Standards

The California Department of Health Services (DHS) has established guidelines for evaluating the compatibility of various land uses as a function of community noise exposure. The level of acceptability

16 The human “threshold of perception” as defined by FTA is not used as significance threshold under CEQA

analysis.



of the noise environment is dependent on the activity associated with the particular land use. Table IV.C-4 (Community Noise Exposure [CNEL]) shows the exterior noise standard associated with various land uses, as described by the State of California land use compatibility for community noise environment.

Table IV.C-4 Community Noise Exposure (CNEL)

Land Use Normally Acceptablea

Conditionally Acceptableb

Normally Unacceptablec

Clearly Unacceptabled

Single-family, Duplex, Mobile Homes 50 - 60 55 - 70 70 - 75 above 75 Multi-Family Homes 50 - 65 60 - 70 70 - 75 above 75 Schools, Libraries, Churches, Hospitals,

Nursing Homes 50 - 70 60 - 70 70 - 80 above 80

Transient Lodging – Motels, Hotels 50 - 65 60 - 70 70 - 80 above 75 Auditoriums, Concert Halls,

Amphitheaters --- 50 - 70 --- above 70

Sports Arena, Outdoor Spectator Sports --- 50 - 75 --- above 75 Playgrounds, Neighborhood Parks 50 - 70 --- 67 - 75 above 75 Golf Courses, Riding Stables, Water

Recreation, Cemeteries 50 - 75 --- 70 - 80 above 80

Office Buildings, Business and Professional Commercial 50 - 70 67 - 77 above 75 ---

Industrial, Manufacturing, Utilities, Agriculture 50 - 75 70 - 80 above 75 ---

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

b 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.

c 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.

d Clearly Unacceptable: New construction or development should generally not be undertaken. Source: City of Los Angeles General Plan Noise Element, adopted February 1999.

As shown in Table IV.C-4, an exterior noise environment up to 65 dBA CNEL is “normally acceptable” for multi-family residential and hotel uses, without special noise insulation requirements, while 75 dBA CNEL and 80 dBA CNEL are identified as “clearly unacceptable” noise level for residential and hotel uses, respectively.

With respect to the Project’s proposed helistop, the Airport Noise Regulations found in Title 21 of the California Code of Regulations (CCR) are utilized.17 The Airport Noise Regulations are based in part on the FAA Part 150 guidelines, which set noise limits for specific aircraft and provide guidance for land use compatibility around airports. These regulations state that the aircraft noise level in a residential setting should be no greater than 65 dBA CNEL. 17 Section 5000, as adopted in 1970 and are administered by the California Department of Transportation

(Caltrans) Division of Aeronautics.



Noise issues with regard to the building sound isolations are addressed in Title 24 of the CCR, as well as local noise standards that are based on state codes.18 Title 24 specifies exterior to interior sound transmission control requirements for new multi-family residential development and hotel rooms, as follows:

• Section 1208A.8.2 – Allowable Interior Noise Levels, states:

Interior noise levels attributable to exterior sources shall not exceed 45 dB in any habitable room. The noise metric shall be either the Day-Night Average Sound Level (Ldn) or the Community Noise Equivalent Level (CNEL), consistent with the noise element of the local general plan.

Worst-case noise levels, either existing or future, shall be used as the basis for determining compliance with this section. Future noise levels shall be predicted for a period of at least 10 years from the time of building permit application.

• Section 1208A.8.4 – Other Noise Sources, states:

Residential structures to be located where the Ldn or CNEL exceed 60 dBA shall require an acoustical analysis showing that the proposed design will limit exterior noise to the prescribed allowable interior noise. The noise element of the local general plan shall be used to the greatest extent possible to identify sites with noise levels potentially greater than 60 dBA.


There are no state vibration standards applicable to the Project. However, the California Department of Transportation (Caltrans) provides guidelines/recommendations to limit groundborne vibration based on the age and/or physical condition of the structures that are located in close proximity to construction activity.19 Table IV.C-5 (Caltrans Guideline Vibration Damage Potential Threshold Criteria) presents the Caltrans guidelines with respect to vibration damage threshold criteria. Although modern industrial/commercial buildings can endure ground vibration levels up to a maximum of 0.5 inch per second PPV, older structures have a much lower vibration tolerance of 0.3 inch per second PPV. Furthermore, buildings of a historical nature, such as the existing Engine Company No. 28 located east of the Project Site, or extremely fragile structures have an even lower vibration damage threshold of 0.08 to 0.25 inch per second PPV as shown in Table IV.C-5. Table IV.C-5 also includes the vibration criteria for underground tunnels, which would be applicable for the Los Angeles County Metropolitan Transportation Authority (Metro) Red Line subway tunnels, located beneath 7th Street adjacent to the Project Site.

18 2001 California Building Code, Division IIA Sound Transmission Control. If the City adopts the International

Building Code (IBC) prior to issuance of the building permit for the Project, the requirements of the IBC would supersede the California Building Code.

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



Table IV.C-5 Caltrans Guideline Vibration Damage Potential Threshold Criteria

Structure and Condition

Maximum PPV (inch per second)

Transient Sourcesa Continuous/Frequent Intermittent Sourcesb

Extremely fragile buildings, ruins ancient monuments 0.12 0.08 Fragile buildings 0.20 0.10 Historic and some old buildings 0.50 0.25 Older residential structures 0.50 0.30 New residential structures 1.00 0.50 Underground tunnels 1.20c 0.50c Modern industrial/commercial buildings 2.00 0.50 a Transient sources created by a single isolated vibration event, such as blasting or drop balls. b Continuous/frequent intermittent sources include impact pile drivers, pogo-stick compactors, crack-and-seat

equipment, vibratory pile drivers, and vibratory compaction equipment. c Vibration criteria based on the Swiss Association of Standardization. Source: Transportation and Construction-Induced Vibration Guidance Manual, Caltrans, 2004, Table 10 and

Table 19.

With respect to human response, studies by Caltrans show vibration velocity levels of 0.01 inch per second PPV would be barely perceptible by humans and levels greater than 0.04 inch per second PPV would be distinctly perceptible, as shown in Table IV.C-6. Also shown on Table IV.C-6 are Caltrans’ criteria in terms of RMS level (VdB). As stated previously, typically, human response to ground vibration is described in terms of VdB criteria. As such, Caltrans PPV threshold criteria (Table IV.C-6) are also presented in VdB levels.

Table IV.C-6 Caltrans Guideline Vibration Annoyance Potential Threshold Criteria

Human Response

Maximum Vibration Velocity, inch/second

Transient Sources a

PPV / VdBc

Continuous/Frequent Intermittent Sources b

PPV / VdBc Barely Perceptible 0.04 / 80 0.01 / 68 Distinctly Perceptible 0.25 / 96 0.04 / 80 Strongly Perceptible 0.90 / 107 0.10 / 88 Severe 2.00 / 114 0.40 / 100 a Transient sources created by a single isolated vibration event, such as blasting or drop balls. b Continuous/frequent intermittent sources include impact pile drivers, pogo-stick compactors, crack-and-seat equipment, vibratory

pile drivers, and vibratory compaction equipment . c VdB limits are calculated based on PPV limits and a crest-factor of 4, per FTA, 2006. VdB = 20*Log(PPV*1,000,000/4). Source: “Transportation- and Construction-Induced Vibration Guidance Manual”(Caltrans, 2004), Table 20.



iii. City of Los Angeles

1. City of Los Angeles Noise Element

The Noise Element of the City of Los Angeles General Plan (General Plan) establishes CNEL guidelines for land use compatibility and includes a number of goals, objectives, and policies for land use planning purposes. The City also has policies and regulations to control unnecessary, excessive, and annoying noise, as cited by LAMC Chapter XI, Noise Regulations. In addition, the L.A. CEQA Thresholds Guide provides guidelines for determining Project impacts and CNEL guidelines for land use noise compatibility. These plans and regulations are described later in this Section.

The overall purpose of the Noise Element of a General Plan is to protect citizens from the harmful and annoying effects of exposure to excessive noise. The following Noise Element policies are applicable to the Project:20

• Policy 2.2: Enforce and/or implement applicable City, state, and federal regulations intended to mitigate proposed noise producing activities, reduce intrusive noise, and alleviate noise that is deemed a public nuisance.

• Policy 3.1: Develop land use policies and programs that would reduce or eliminate potential and existing noise impacts.

2. City of Los Angeles Noise Regulation

Chapter XI of the LAMC 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. In accordance with the LAMC, a noise level increase of 5 dBA over the existing ambient noise level at an adjacent property line is considered a noise violation. To account for people’s increased tolerance for short-duration noise events, the LAMC allows an additional 5 dBA increase for a noise lasting more than five, but less than 15 minutes, in any one-hour period (for a total of a 10 dBA increase above the ambient noise level), and an additional 5 dBA increase (for a total of a 15 dBA increase above the ambient noise level) for a noise lasting five minutes or less in any one-hour period.21

The ambient noise, as defined by the LAMC, is the measured noise level averaged over a period of at least 15 minutes (Leq[15-minute]). For purposes of determining whether or not a violation of the noise regulations is occurring, the sound level measurements of an offending noise are be averaged over a minimum duration of 15-minutes, and compared with the baseline ambient noise levels. The baseline ambient noise is the actual measured ambient noise level or the City’s presumed ambient noise level as shown in Table IV.C-7 (City of Los Angeles Presumed Ambient Noise Levels), whichever is greater. In cases in which the actual measured ambient noise level is not known, the City’s presumed ambient noise

20 Noise Element of the Los Angeles City General Plan, adopted February 3, 1999. 21 Los Angeles Municipal Code, Chapter XI, Article I, Section 111.02-(b).



level will be used as the baseline. As indicated in Table IV.C-7, the City’s presumed daytime (7:00 a.m. to 10:00 p.m.) minimum ambient noise level for properties zoned residential is 50 dBA, while the nighttime (10:00 p.m. to 7:00 a.m.) presumed minimum ambient noise level is 40 dBA. The presumed daytime minimum ambient noise level for properties zoned commercial is 60 dBA, while the nighttime presumed minimum ambient noise level is 55 dBA.

Table IV.C-7 City of Los Angeles Presumed Ambient Noise Levels

Zone

Daytime (7 a.m. to 10 p.m.)

Leq (dBA)

Nighttime (10 p.m. to 7 a.m.)

Leq (dBA) Residential, School, Hospital, Hotel 50 40 Commercial 60 55 Manufacturing (M1, MR1 and MR2) 60 55 Heavy Manufacturing (M2 and M3) 65 65 Source: LAMC, Section 111.03.

In addition, the LAMC also limits noise from construction equipment located within 500 feet of a residential zone to 75 dBA, measured at a distance of 50 feet from the source, unless compliance with this limitation is technically infeasible.22 Furthermore, the LAMC prohibits construction noise between the hours of 9:00 p.m. and 7:00 a.m. Monday through Friday, and on Saturday before 8:00 a.m. and after 6:00 p.m., and all day on Sundays.23

3. City of Los Angeles Noise Compatibility Guidelines

The City has adopted local guidelines based, in part, on the community noise compatibility guidelines established by the State Department of Health Services for use in assessing the compatibility of various land use types with a range of noise levels. These guidelines are set forth in the L.A. CEQA Thresholds Guide in terms of the CNEL. CNEL guidelines for specific land uses are classified into four categories: “normally acceptable;” “conditionally acceptable;” “normally unacceptable;” and “clearly unacceptable.” As presented in Table IV.C-3, a CNEL value of 70 dBA is the upper limit of what is considered a “normally acceptable” noise environment for educational uses. For more sensitive uses such as multi-family residential, the upper limit of what is considered “normally acceptable” is set at 65 dBA CNEL.24

22 In accordance with the City of Los Angeles Noise Regulations (Los Angeles Municipal Code, Section 112.05),

‘technically infeasible’ means that said noise limitations cannot be complied with despite the use of mufflers, shields, sound barriers, and/or other noise reduction devices or techniques during the operation of the equipment.

23 Los Angeles Municipal Code, Section 41.40. 24 L.A. CEQA Thresholds Guide, Section I.2, 2006.



4. City of Los Angeles Vibration Standards

The City does not currently have any adopted standards, guidelines, or thresholds relative to groundborne vibration for Project construction and operations.

d. Existing Noise Conditions

i. 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, schools, motels and hotels, libraries, religious institutions, hospitals, nursing homes, auditoriums, concert halls, amphitheaters, and parks are generally more sensitive to noise than commercial and industrial land uses. Noise-sensitive receptors were selected in accordance with the L.A. CEQA Thresholds Guide screening criteria and to provide a representative sampling of the surrounding noise environment. Sensitive receptors in the Project area include the following:

• Various multi- and single-family residential land uses (refer to Table IV.C-8);

• Los Angeles Central Library, various schools and educational facilities;

• Various hotels and private clubs; and

• Good Samaritan Hospital.

ii. Existing Ambient Noise Levels

Ambient noise measurements were taken at the Project Site and at 19 nearby off-site locations. The off-site noise measurements locations range from 60 feet to approximately 6,000 feet from the Project Site representing residential, schools, commercial, and religious land uses. The description of the noise measurement locations is provided in Table IV.C-8 (Description of Noise Measurement Locations) and Figure IV.C-1 (Noise Measurement Locations) shows the locations of the noise measurement locations, which are identified as P1 (Project Site) and R0 through R18 (off-site locations). The nearest off-site noise sensitive receptors (i.e., multi-family residential uses) to the Project Site include: The Jonathan Club (R17), The Pegasus apartments (near R11), Roosevelt Lofts (near R10), The Piero apartments (R4), and 1010 Wilshire apartments (near R4 and R6), which are located approximately 500 feet away from the Project Site. Schools are located at noise receptor locations R15 and R18, and the Jonathan Club is located at noise receptor location R17. The noise measurement location P1 was selected to quantify the existing ambient noise level at the Project Site and to determine the land use compatibility of the Project’s land uses. Long-term (24-hour) measurements were conducted at the Project Site (location P1) and the noise metering device was placed on the roof of the existing on-site building. Generally, at the roof elevation the ambient sound level is few decibels higher than that of the grade level noise environment. At the building roof elevation, over 160 feet high (i.e., the roof of the existing on-site building), the noise meter has a



Table IV.C-8 Description of Noise Measurement Locations

Location Description

Approximate Distance to Project Site

(Feet)a

Representing Nearby

Land Uses

Sensitive Receptor

?

P1 On the roof level of the existing Wilshire Grand Hotel and Centre, at the northwest corner of the building

on-site Commercial N/A

R0 Office building at 1000 Wilshire Blvd., across from the Project Site

60 Commercial No

R1 In front of the office building at 915 Wilshire Blvd., across from the Project Site

80 Commercial No

R2 In front of the office building at 654 Figueroa St., across from the Project Site

75 Commercial No

R3 In front of the office building at 725 Figueroa St., across from the Project Site

85 Commercial No

R4 In front of the multi-family building, on the east sidewalk of St. Paul Ave., just north of Wilshire Blvd.

500 Residential/ Office

Yes

R5 In front of the multi-family building, on the south sidewalk of 7th St., east of Bixel St.

700 Residential/ Office

Yes

R6 In front of the multi-family building, on the west sidewalk of Bixel St., just south of Wilshire Blvd.

1,000 Residential/ Commercial

Yes

R7 In front of the Sheraton Hotel, on the west sidewalk of Hope St., south of 7th St.

800 Hotel/ Commercial/

Religious Facilities

Yes

R8 In front of the Westin Bonaventure Hotel and Suites, on the east sidewalk of Figueroa St., north of 5th St.

1,300 Hotel/ Commercial

Yes

R9 In front of the multi-family building, on the east sidewalk of Figueroa St. (north of Olympic Blvd.)

1,500 Hotel/ Residential/ Commercial

Yes

R10 In front of the multi-story building, on the south sidewalk of Wilshire Blvd., just west of Hope St.

800 Residential/ Commercial

Yes

R11 In front of the Standard Hotel, on the east sidewalk of Flower St., just north of 6th St.

700 Hotel/ Residential/ Commercial/

Religious Facilities

Yes

R12 In front of the multi-family building, on the east sidewalk of Flower St. (between 8th and 9th Sts.)


Yes

R13 In front of the Good Samaritan Hospital, on the west sidewalk of Bixel St.

1,700 Hospital Yes

R14 In front of the single-family residential building, on the north sidewalk of Colton St., west of Glendale Blvd.


Yes

R15 9th Street Elementary School, on the west sidewalk of Stanford Ave., between 8th and 9th Sts.

6,000 School/ Commercial

Yes

R16 In front of the multi-family residential building, on the east sidewalk of Beacon Ave., south of 8th St.


Yes



Table IV.C-8 Description of Noise Measurement Locations

Location Description

Approximate Distance to Project Site

(Feet)a

Representing Nearby

Land Uses

Sensitive Receptor

?

R17 In front of the Jonathan Club building at 545 Figueroa St.

450 Hotel/ Commercial

Yes

R18 In front of the Miguel Contreras Learning Center, on the north sidewalk of 4th St., between Bixel St. and Lucas Ave.

2,200 School/ Residential

Yes

a Distances are based on Google Earth map. Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).

direct line-of-sight to the nearby Interstate 110 (the “Harbor Freeway”). Thus, the meter on the roof would likely register slightly higher noise levels as compared with the ambient levels at the grade level. Three short-term (15-minute) measurements were conducted at each of the 19 off-site locations during the daytime hours (two measurements between the hours of 9:00 a.m. and 4:00 p.m.) and nighttime hours (one measurement between 10:00 p.m. and 1:00 a.m.).

Table IV.C-8 presents the measured ambient noise levels in the vicinity of the Project Site, using the noise measurement locations as indicators Based on field observation and measured sound data, the current ambient noise environment in the vicinity of the Project Site is controlled primarily by vehicular traffic on local roadways and the Harbor Freeway, and to a lesser extent by occasional aircraft flyovers, and other typical urban noise. At the Project Site (P1), the daytime ambient noise levels ranged from 69.1 dBA (Leq) to 75.3 dBA (Leq). The existing ambient noise levels at all measurement locations currently exceed the City’s presumed daytime and nighttime ambient noise standards, as indicated in Table IV.C-9 (Measured Ambient Noise Levels).

iii. Traffic Noise Levels

In addition to the ambient noise measurements in the vicinity of the Project Site, the existing traffic noise on local roadways near the Project Site was calculated to quantify the 24-hour CNEL noise levels, using information taken from the Project’s transportation study (refer to the Appendix IV.B). The transportation study area, which encompasses approximately 10 square miles, is bounded by Cesar E. Chavez Avenue/Temple Street on the north, Washington Boulevard on the south, Soto Street on the east, and Hoover Street and Alvarado Street on the west. A total of 42 intersections were analyzed as part of the transportation study. Twenty-eight 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. The traffic noise level was calculated using the Federal Highway Administration (FHWA) Traffic Noise Model (TNM) and traffic volume data from the Project’s traffic study. The TNM traffic noise prediction model calculates the hourly Leq noise levels based on specific

PROJECTSITE

R3

R4R6

R7

R8

R9

R10

R11

R12

R13

R15

R16

R14

R17

R18

R0 R1

R2P1

R5

Source: Acoustical Engineering Services, 2010.

Figure IV.C-1Noise Measurement Locations

NOT TO SCALE

Legend

Noise Measurement Locations

Yellow – Within Project Site

Green – Receptor location falls under City’s definition of a sensitive receptor (i.e., residential, school, hotel, religious)

Blue – Office/Commercial uses (non-sensitive receptor)

P1

RX

RX



Table IV.C-9 Measured Ambient Noise Levels

Location Measurement

Date

Measured Noise Levels, a Leq (dBA)

CNEL (dBA)

Sensitive Receptor?

Daytime (7 a.m. to 10 p.m.)

Nighttime (10 p.m. to

7 a.m.) P1 7/22/2009

7/23/2009 7/24/2009

69.5 – 73.5 69.1 – 75.3 72.1 – 74.7

72.2 – 73.5 67.7 – 75.4 69.1 – 75.3

78.8 78.5 80.8 N/A

R0 12/17/2009 67.7-68.9 66.7 71.7b No R1 7/23/2009 71.4 – 72.1 65.0 72.0 b No R2 7/23/2009 73.8 – 74.4 70.4 76.1 b No R3 7/23/2009 70.9 – 71.3 65.8 72.1 b No R4 7/23/2009 64.5 – 70.9 61.0 68.6 b Yes R5 7/23/2009 72.3 – 73.6 69.3 75.0 b Yes R6 7/23/2009 70.8 – 71.1 66.0 72.2 b Yes R7 7/22/2009 &

7/23/2009 66.2 – 68.1 63.1 68.9 b

Yes R8 7/23/2009 &

7/24/2009 72.7 – 74.6 67.1 74.1 b

Yes R9 7/23/2009 70.0 70.9 75.4 b Yes

R10 7/22/2009 & 7/23/2009

70.6 – 71.2 64.0 71.1 b Yes

R11 7/23/2009 73.4 – 75.9 64.1 73.7 b Yes R12 7/22/2009 &

7/23/2009 68.5 – 69.7 65.3 71.0 b

Yes R13 7/23/2009 62.9 – 64.1 60.9 66.2 b Yes R14 7/22/2009 &

7/24/2009 56.0 – 58.6 58.4 62.9 b

Yes R15 7/22/2009 &

7/24/2009 62.5 – 64.4 55.8 63.4 b

Yes R16 7/22/2009 &

7/24/2009 57.8 – 58.4 57.3 62.1 b

Yes R17 1/12/2010 65.9-66.9 65.3 70.2b Yes R18 1/12/2010 58.2-59.0 54.5 60.3b Yes

a Detailed measured noise data, including hourly Leq levels, are included in Appendix IV.C.1. b Calculated based on the short-term measurements. Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).

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



Table IV.C-10 (Existing Roadway Traffic Noise Levels) provides the calculated CNEL for the analyzed local roadway segments based on existing traffic volumes. As shown therein, the existing CNEL due to surface street traffic volumes ranged from 66.2 dBA CNEL along Francisco Street (between 7th Street and Wilshire Boulevard) to 73.6 dBA CNEL along Figueroa Street (between 5th Street and Wilshire Boulevard). Currently, the existing traffic related noise levels at the nearest sensitive receptors to each analyzed roadway segment exceed normally acceptable (i.e., 65 dBA CNEL or lower) noise levels at a majority of the studied residential areas.

Table IV.C-10 Existing Roadway Traffic Noise Levels

Roadway Segment

Exiting Traffic

Volume, ADT

Distance to Roadway

Centerline, feet

Calculated Traffic Noise

Levels,a CNEL

Adjacent Land Uses

Existing Noise Exposure

Compatibility Category b

Glendale Blvd. - Between Temple St. and Beverly Blvd. 25,770 35 73.2 Commercial 2

Francisco St. - Between 7th St. and Wilshire Blvd.

5,155

25

66.2

Commercial

1

Lucas Ave. - Between 3rd St. and 6th St. 9,670 25 70.2 Residential/

School 3

- Between 6th St. and Wilshire Blvd. 7,065 25 68.8 Hospital 2

Wilshire Blvd. - Between Alvarado St. and Lucas Ave. 20,545 40 71.6 School 3 - Between Lucas Ave. and Beaudry Ave. 19,290 40 71.3 Residential 3 - Between Francisco St. and Figueroa St. 17,035 40 70.8 Hotel/Office 3 - Between Figueroa St. and Grand Ave. 11,430 40 69.0 School 2

6th St. - Between Figueroa St. and Flower St. 10,525 35 69.3 Commercial 2 - Between Flower St. and Olive St. 9,207 35 68.7 Commercial 2 - East of Olive St. 12,280 35 70.0 Park 3

7th St. - Between Alvarado St. and Bixel St. 7,359 35 67.7 Residential/

School 2

- Between Bixel St. and Francisco St. 7,444 35 67.8 Residential 2 - Between Francisco St. and Figueroa St. 8,145 35 68.2 Hotel/Office 2 - Between Figueroa St. and Grand Ave. 8,518 35 68.4 Hotel 2 - Between Grand Ave. and Alameda

Blvd. 7,466 35 67.8 Religious 2

Figueroa St. - Between 3rd St. and 5th St. 30,300 40 73.3 Hotel 3 - Between 5th St. and Wilshire Blvd. 32,835 40 73.6 Office/Private 2



Table IV.C-10 Existing Roadway Traffic Noise Levels

Roadway Segment

Exiting Traffic

Volume, ADT

Distance to Roadway

Centerline, feet

Calculated Traffic Noise

Levels,a CNEL

Adjacent Land Uses

Existing Noise Exposure

Compatibility Category b

Club - Between Wilshire Blvd. and 7th St. 23,705 40 72.2 Hotel/Office 3 - Between 7th St. and Olympic Blvd. 19,270 40 71.3 Residential 3 - Between Olympic Blvd. and Pico Blvd. 20,485 40 71.6 Residential 3

Flower St. - Between 3rd St. and 5th St. 17,460 40 70.9 Hotel 3 - Between 5th St. and Wilshire Blvd. 16,030 40 70.5 Office 2 - Between Wilshire Blvd. and 8th St. 19,410 40 71.3 Office 2 - South of 8th St. 17,170 40 70.8 Residential 3

Grand Ave. - Between 3rd St. and Wilshire Blvd. 12,495 40 69.4 Church 2 - Between Wilshire Blvd. and 7th St. 15,885 40 70.5 Office 2 - South of 7th St. 13,880 40 69.9 Residential 3

a Detailed calculation worksheets, are included in Appendix IV.C.1. b 1 = Normally Acceptable, 2 = Conditionally Acceptable, 3 = Normally Unacceptable, 4 = Clearly Unacceptable. Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).

e. Existing Groundborne Vibration

Based on field observations, the primary source of existing groundborne vibration in the Project vicinity is vehicular travel (i.e., refuse trucks, delivery 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. In part, the FTA study reports “it is unusual for vibration from traffic including buses and trucks to be perceptible, even in locations close to major roads.”25 Therefore, based on the FTA’s published vibration data, the existing ground vibration environment in the vicinity of the Project Site would be below the perceptible level.

25 Transit Noise and Vibration Impact Assessment, Chapter 7, FTA, 2006.



2. ENVIRONMENTAL IMPACTS

a. Thresholds of Significance

Based on thresholds provided by the L.A. CEQA Thresholds Guide and Appendix G to the State CEQA Guidelines the following thresholds of significance were developed to evaluate Project noise and vibration impacts:

i. Construction Noise

A project would normally have a significant impact on noise levels from construction if one or more of the following were to occur:

• Construction activities lasting more than one day would exceed existing ambient exterior sound levels by 10 dBA or more at a noise-sensitive use;

• Construction activities lasting more than 10 days in a three-month period would exceed existing ambient exterior noise levels by 5 dBA or more at a noise-sensitive use; or

• Construction activities would exceed the ambient noise level by 5 dBA at a noise-sensitive use between the hours of 9:00 p.m. and 7:00 a.m. Monday through Friday, before 8:00 a.m. or after 6:00 p.m. on Saturday, or at anytime on Sunday.


1. Traffic Noise and On-Site Noise Sources

As discussed previously with respect to the community noise assessment, changes in noise levels less than 3 dBA are generally not discernable to most people, while changes greater than 5 dBA are readily noticeable and would be considered a significant increase. Therefore, the significance threshold for Project-related on-site stationary and off-site noise sources is based on aforementioned changes in noise levels (increases), with consideration of existing ambient noise conditions and the City’s land use noise compatibility guidelines. A threshold of a 5 dBA increase is used where existing ambient noise conditions fall within the City’s acceptable noise environment. Otherwise, where the existing ambient noise level exceeds the City’s acceptable noise levels, a 3 dBA increase together with other relevant circumstances is utilized as a threshold. This threshold is therefore conservative, as it accounts for the current noise environment.

As noted in Table IV.C-4, community noise levels of up to 70 dBA CNEL are considered conditionally acceptable for the residential land uses located downtown in the vicinity of the Project. However, as indicated in Table IV.C-7, existing measured noise levels at all receptor locations in the immediate vicinity of the Project (Measurement Locations P1 and R1 through R12 and R17) are either already above 70 dBA or would be above 70 dBA with a 3 dBA increase. Therefore, to be conservative, this EIR utilizes the threshold of 3 dBA CNEL increase in noise levels together with other relevant circumstances to identify a significant impact from traffic and on-site operational noise sources associated with the



Project at these locations. In the case of the alternate traffic impact scenario (see Page IV.C-53), a threshold of 5 dBA was used for commercial uses along Francisco Street.

2. Helicopter Noise


As discussed previously, the FAA has identified a screening threshold for determining whether aviation operations could be incompatible with residential uses that are located within the 65 dBA Ldn contour or lower (65 dBA CNEL for projects in California). Under this threshold, unless a project causes a 1.5 dBA increase or less within the 65 dBA CNEL or greater area, there will not be a 3 dBA or greater (i.e., audible) increase in the 60-65 dBA CNEL area. The City of Los Angeles has adopted this threshold in the L.A. CEQA Thresholds Guide.

(b) Sleep Disturbance and Speech Interference

As described previously, with respect to the helicopter noise, in addition to the land use compatibility (i.e., CNEL) significance threshold, the effects of single-event noise are also used to evaluate the potential noise impact with regard to sleep disturbance at noise-sensitive uses. No specific thresholds for an evaluation of the effect of single-event aircraft noise in addition to time-averaged levels have been developed by state or federal agencies. For purposes of the analysis in this EIR, the SEL value that represents 10 percent of the population being awakened was considered appropriate, because this level would reflect the relatively small subset of the general population that may be particularly sensitive to single-event noise as a cause of nighttime awakening. As noted previously, the FICAN 1997 curve predicts that, at an interior SEL of 81 dBA, 10 percent of the affected population would be awakened. For purposes of the analysis in this EIR, the SEL significance threshold conservatively assumes that nearby residential, hotel, and hospital uses have openable windows, which provide a maximum 13 dB noise reduction from exterior noise levels. To the extent that nearby residential, hotel, and hospital usesdo not have openable windows, the exterior-to-interior noise reduction would be greater. With a 13 dB noise exterior-to-interior noise reduction, exterior SEL of up to 94 dBA would be permissible without exceeding the 81 dbA interior SEL threshold. Although the SEL significance criterion is intended in determining the potential for sleep disturbance, it is utilized to identify the impacts on sensitive land uses at any time during the 24-hour period, as a conservative threshold.

Based upon a literature search conducted for the Project, it was noted that the effects of single event aircraft noise has been utilized in CEQA analyses prepared for airport and heliport projects in California.26, 27, 28 In these analyses, the single event noise impacts assessments focused primarily on the effects of aviation noise on sleep and classroom speech interference.

26 Berkeley Keep Jets Over the Bay Committee vs. Board of Port Commissioners, (2001) 91 Cal. App. 4th 1344. 27 UCSF Medical Center at Mission Bay Final EIR, Chapter 4.5 “Noise”, September 2008. 28 Los Angeles International Airport, South Airfield Improvement Project EIR, August 2005.



A noise criterion in terms of Lmax is used to evaluate potential impacts on speech interference, with respect to school uses. The nearest known schools to the Project Site are the Miguel Contreras High School and the Evelyn Thurman Gratts Elementary School, which are located approximately 2,200 feet north of the Project Site. These school sites are represented by receptor R18. These schools are newly constructed and likely include indoor mechanical air conditioning systems, allowing classroom windows to remain closed during daily operation. The school’s building shell structures, including windows in a closed position, are estimated to provide a minimum of 25 dBA exterior to interior noise reduction. As previously discussed, a maximum noise level (Lmax) of 55 dBA is recommended at the interior of the school classroom.29 Therefore, based on the estimated minimum 20 dBA noise reduction provided by the school building structures and the recommended interior noise level of 55 dBA (Lmax), the Project helicopter operation-related noise level at the school site should be limited to 80 Lmax.

3. Summary of Operational Noise Significance Thresholds

Based on each of the considerations discussed previously, Project operations could have significant noise impacts if one or more of the following would occur:

• Project operations will cause the ambient noise level measured at the property line of affected noise-sensitive uses to increase by 5 dBA CNEL within the “normally acceptable” or “conditionally acceptable” category, where existing ambient noise conditions fall within the City’s acceptable noise environment.

• Project operations, considering all relevant circumstances, will cause the ambient noise level measured at the property line of the affected noise-sensitive uses to increase by 3 dBA CNEL within the “normally acceptable” or “conditionally acceptable” category, where existing ambient noise conditions already fall above the City’s acceptable noise environment.

• Project helistop operation would cause a significant noise impact if a noise sensitive land use is already experiencing existing noise levels at or above CNEL 65 dBA and would experience an increase in level of 1.5 dBA or greater due to helistop operations;

• Project helistop operation would generate a SEL of 94 dBA or greater at the exterior of noise-sensitive (i.e., residential, hotel, and hospital) structures in the vicinity of the Project Site; and

• Project helistop operation would generate Lmax of 80 dBA or greater at the exterior of school structures in the vicinity of the Project Site.

iii. Groundborne Vibration (Construction and Operation)

The City currently does not have a significance threshold to assess construction vibration impacts. Thus, the FTA and Caltrans’ standards described earlier are used to evaluate potential vibration impacts

29 Environmental Protection Agency (EPA), Information on Levels of Environmental Noise Requisite to Protect

Public Health and Welfare with an Adequate Margin of Safety, March 1974.



associated with Project construction. Therefore, Project construction activities could have significant vibration impacts if the following were to occur:

• Project construction activities cause a PPV groundborne vibration level to exceed 0.5 inch per second at any off-site structures (above and below ground structures) with the exception of the Mullen Building/Historic Fire Station No. 28, in which a PPV of 0.1 inch per second would be used.

The primary sources of Project operation-related vibration would include passenger vehicle circulation within the proposed parking facility and on-site delivery truck activity, which would be similar to the existing conditions, including the existing on-site subterranean parking structure and roadways adjacent to the Project Site. In addition, the Project would include typical commercial-grade stationary mechanical and electrical equipment such as air handling units, condenser units, cooling towers, exhaust air fans, and electrical power generators that would produce vibration similar to the existing Wilshire Grand Hotel and Centre. Typically, ground-borne vibration attenuates rapidly as function of distance from the vibration source. Furthermore, most of the Project’s operational-related vibration sources, such as mechanical and electrical equipment, would incorporate vibration attenuation mounts, as required by the particular equipment specifications. Therefore, the proposed 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 operation would be less than significant. Therefore, ground-borne vibration analysis is limited to Project-related construction activities.

b. Methodology

i. Ambient Noise Measurement

Noise measurements were conducted using Larson-Davis 820 Precision Integrated Sound Level Meter (SLM). The Larson-Davis 820 SLM is a Type 1 standard instrument as defined in the American National Standard Institute (ANSI) S1.4. All instruments were calibrated and operated according to the manufacturer’s written specifications. The microphone was placed at a height of five feet above the local grade, with the exception of location P1 where the microphone was placed at the roof level of the existing Wilshire Grand Hotel and Centre. The sound level meters were setup to collect the average (Leq) noise levels over a minimum 15-minute period. In accordance with the City’s noise ordinance, the ambient noise measurements were conducted continuously for a period of a minimum of 15 minutes.

ii. Construction Noise

Construction noise impacts were evaluated by calculating the construction-related noise level at various locations in the Project area (i.e., receptor locations R0 to R18), including noise-sensitive locations, and comparing these construction-related noise levels to the existing ambient noise levels. Construction noise associated with the Project was assessed using specified construction equipment inventory, construction durations, and construction phasing. Construction information was provided by Turner Construction, included in Appendix IV.C.1. The construction noise model for the Project is based on construction equipment noise levels as published by FHWA. The existing ambient noise levels at surrounding



sensitive receptor locations were estimated based on field measurement data. The estimated noise levels that would occur during the Project’s construction phase were then calculated for the selected noise receptor locations based on the standard point source noise-distance attenuation factor of 6.0 dBA for each doubling of distance. Additional noise attenuations were assigned to receptor locations where their line-of-sight to the Project Site was interrupted by the presence of intervening structures.

iii. Operational Noise

1. Off-Site Roadway Noise

Off-site roadway noise was assessed using the FHWA’s TNM, constructed based on the roadway traffic data provided in the Project’s transportation study (refer to Appendix IV.B). 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 any) locations. Roadway noise under the “Future with Project” scenario was calculated and compared to baseline noise levels that would occur under the “Future without Project” scenario, to determine the Project noise impacts.

Project-related off-site construction truck noise impacts were assessed using the TNM computer noise model. The construction related off-site truck volumes were obtained from the Project’s transportation study (refer to Appendix IV.B). The TNM noise model calculates the hourly Leq noise levels generated by construction-related trucks. Noise impacts were determined by comparing the predicted noise levels with that of the existing ambient noise levels.

2. On-Site Stationary Noise Sources

Stationary point-source noise impacts were assessed by identifying the noise levels generated by outdoor stationary noise sources, such as rooftop mechanical equipment and loading dock activities, calculating the hourly Leq noise level from each noise source at surrounding noise-sensitive receiver property line locations, and comparing such noise levels to existing ambient noise levels.

3. Helistop Operation

Helicopter operation-related noise contours were calculated using the FAA Integrated Noise Model (INM) Version 7.0a. The INM Version 7.0a model is the latest noise model from the FAA that includes noise analysis for helicopter operations. The INM input information includes: three dimensional flight tracks (departure and approach), helicopter flight procedures, number and type of helicopters, and daily operations (number of flights by hours). This information was provided by Heliport Consultants and is detailed in Appendix IV.C.2. The INM noise model calculates helicopter operations related CNEL and SEL noise levels at a particular receptor location.

4. Composite Noise Levels

The Project composite noise level was calculated to evaluate the potential increase in noise levels that may occur at the analyzed noise-sensitive receptor locations. The composite noise level includes



contributions from each individual noise source associated with the typical daily operation of the Project. Primary noise sources associated with the Project would include off-site vehicular traffic, and the on-site mechanical equipment, parking facility, outdoor services, and use of the Helistop. The noise analyses for the individual Project-related noise sources were made using various noise descriptors (i.e., 24-hour CNEL, 1-hour Leq, SEL and Lmax). However, in order to evaluate the combined noise effect of all noise sources, a common noise descriptor, CNEL, is used. The Project composite noise level was determined by combining the noise levels from individual Project-related noise sources (in terms of CNEL), at each of the analyzed noise receptors. Noise impacts were determined by comparing the composite noise levels with that of the existing ambient noise levels.

5. Cumulative Impacts (Construction)

Cumulative noise level impacts due to construction activities from the Project combined with the related projects (see Section III., Environmental Setting) were analyzed to evaluate potential cumulative noise impacts. The potential for cumulative noise impacts to occur is based on the distance between the Project and each of the related projects. Noise from construction activities would normally affect the areas immediately adjacent to each of the construction sites, specifically areas that are less than 500 feet from a construction site (500 feet distance is identified by the L.A. CEQA Thresholds Guide as the Screening Criteria with respect to construction activities). That is, cumulative noise impacts could occur at receptor locations that are within 500 feet from two different construction sites. Therefore, based on the 500 feet screening criteria distance, the cumulative construction noise impact analysis is limited to related projects within 1,000 feet of the Project Site. The 1,000 feet distance is based on an assumption that a noise sensitive receptor would be located halfway between the Project Site and the related project.

6. Cumulative Impacts (Construction Vibration)

Due to the rapid attenuation characteristics of ground-borne vibration, the potential for a cumulative construction vibration impact (with respect to building damage) would be limited to related projects that are located in close proximity (within 100 feet) of the Project Site. Furthermore, construction vibration impacts were analyzed based on the instantaneous peak vibration level produced by each piece of construction equipment.

7. Cumulative Impacts (Operation)

With respect to long-term operation, the Project and the related projects in the surrounding area would generate noise that would contribute to cumulative noise from a number of community noise sources including off-site vehicle travel and on-site sources such as mechanical equipment. Detail information regarding the on-site noise sources from the related projects is typically not available at this stage of the project. However, each related project would be designed (including mitigation measures as required) to meet the City’s exterior noise limits at the property line. Therefore, noise impacts attributable to cumulative development of the related projects and the Project would result in less than significant impacts. However, each related project would produce traffic volumes (off-site vehicle) that are capable of generating roadway noise impacts. Cumulative noise impacts due to off-site vehicle traffic were



analyzed by comparing the projected increase in traffic noise levels from “existing” conditions to “future cumulative” conditions with the Project to the applicable significance criteria. The off-site vehicle traffic noise analysis methodology is described above. Future cumulative conditions include traffic volumes from future ambient growth, related development projects, and the Project.

iv. Groundborne Vibration (Construction)

Groundborne vibration impacts due to construction activities were assessed by identifying potential vibration sources, estimating the vibration levels at the affected receptor, and comparing with the Project significance thresholds. The vibration levels for various types of equipment that could be used during the Project’s construction phase were based on data provided by the FTA.

c. Project Design Features

The following listed project design features would avoid or reduce Project-related noise effects, and therefore, were taken into account during the analysis of potential Project impacts.

i. Construction

• Project construction would not include the use of pile driving, to reduce construction noise and vibration impacts.

• A temporary six-foot-tall noise barrier wall would be installed at the construction area along the Francisco Street where construction trucks are lining up prior to entering the Project’s construction site. The barrier would be placed on the top of the two-foot-tall K- rail that would increase the effective height of the noise barrier to eight feet.

ii. Operation

• All mechanical equipment would be enclosed and designed to meet the requirements of LAMC, Chapter XI, Section 112.02. The building mechanical/electrical equipment shall be designed not to exceed 63 dBA Leq (or 70 dBA CNEL) noise level at the Project Site property line. The building mechanical design shall be reviewed by a qualified acoustical consultant to ensure that the design shall meet the Project noise criteria.

• The sound output of the proposed outdoor amplified sound systems for the outdoor pool and bar areas would be limited to a maximum sound level of 80 dBA Leq as calculated in Section 5.4.1.4. The design of the outdoor amplified sound systems would be reviewed by a qualified acoustical consultant to ensure that the design would meet the Project noise criteria.

• The sound output of the proposed outdoor amplified sound systems for the outdoor plaza would be limited to a maximum sound level of 70 dBA (Leq) at 50 feet as calculated in Section 5.4.1.4. The design of the outdoor amplified sound systems would be reviewed



by a qualified acoustical consultant to ensure that the design would meet the Project noise criteria.

• The podium and rooftop parapets for areas that include an outdoor amplified sound system shall be of solid panel construction to provide sound attenuation.

• If the proposed loading docks and trash/recycling areas would be located outside of the enclosed parking structure, all outdoor loading dock and trash/recycling areas shall be fully or partially enclosed such that the line-of-sight between these noise sources and any adjacent noise sensitive receptor shall be obstructed.

• Building shell construction (i.e., exterior wall, window and door) would provide adequate sound insulation to meet the acceptable interior noise level of 45 dBA CNEL, as required by the Title 24 of the California Code of Regulations.

• Unless required for safety precautions, the Project’s related helicopters shall use the recommended flight paths as described in the Heliport Consultant Report (refer to Appendix IV.C.2).

d. Project Impacts

i. Construction Noise and Vibration Impacts

1. Construction Noise

Noise impacts from Project construction activities occurring within or adjacent to 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 include site demolition, excavations and shoring, and building construction. Each stage of construction would involve the use of various types of construction equipment and therefore, each stage would have its own distinct noise characteristics. Site demolition generally involves the use of backhoes, front-end loaders, and heavy-duty trucks. Excavation and shoring 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.

Construction of the Project would occur over 54 consecutive months and would generally follow the following stages:

• Site Demolition and Abatement (removal of existing buildings);

• Excavation and Shoring (for the subterranean garage and building foundation);



• Construction of the garage, hotel/office buildings, and on-site/off-site improvements (driveways and landscape).

Individual pieces of construction equipment that would be used for construction produce maximum noise levels of 75 dBA to 84 dBA at a reference distance of 50 feet from the noise source, as shown in Table IV.C-11 (Noise Levels Generated by Typical Construction Equipment). The construction equipment noise levels at 50 feet distance (Referenced Maximum Noise Levels) are based on the FHWA Roadway Construction Noise Model User’s Guide (RCNM), which is a report containing actual measured noise data for construction equipment. The maximum noise levels would occur when the equipment is operating under full power conditions. However, since equipment used on construction sites often operates at less than full power, an acoustical usage factor is applied. The acoustical usage factor is a percentage of time that a particular piece of equipment is anticipated to be in full power operation during a typical construction day. These acoustical usage factors are estimates and will vary based on the actual construction activities and duration.

Table IV.C-11 Noise Emission Reference Levels and Usage Factors

Type of Equipment Acoustical Usage Factor (%)

Reference Maximum Noise Levels at 50 Feet,a Lmax

(dBA) Backhoe 40 78 Concrete Pump 20 81 Concrete Truck 40 79 Crane, Mobile 16 81 Dozer 40 82 Drill Rig 20 84 Excavator 40 81 Forklift 50 75 Loader 40 79 Skid Steer Loader 40 79 Dump/ Haul/ Delivery Truck 40 76 Water Truck 20 82 a Construction equipment noise levels are based on the FHWA RCNM. These levels are based on actual

measurement of construction equipment made in the 1990s for the Central Artery/Tunnel project in Boston, Massachusetts, which are newer data than those published in the L.A. CEQA Thresholds Guide, which is based on the 1971 EPA (Environmental Protection Agency) document.

Source: FHWA Roadway Construction Noise Model User’s Guide, Table 1, 2006; Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).

To more accurately characterize construction-period noise levels, the average (Hourly Leq) noise level associated with each construction stage was calculated based on the quantity, type, and usage factors for each type of equipment that would be used during each construction stage and are typically attributable to multiple pieces of equipment operating simultaneously. Information with respect to construction



equipment that would be used was provided by the Project construction management consultant, Turner Construction (refer to Appendix IV.C.1).

Table IV.C-12 (Construction Noise Impacts) provides a summary of construction-related noise levels that would occur at the receptor locations during the different phases of Project construction activity, based on existing ambient noise levels and distance of the receptor from the boundary of the Project Site. With respect to the Project construction activities, the highest levels of noise would be generated primarily during site demolition and excavation and shoring. Soft demolition of the building interior would proceed from the top level down. Soft items, such as drywall, insulation, adhesives, etc, would be demolished and removed using bobcat tractors. Excavators, backhoes and a crane could be used to take down the concrete and steel structure. The concrete encased steel beams would be stripped of the concrete on-site using a jackhammer mounted to a backhoe. Since the proposed parking structure is deeper than the existing parking structure, the demolition of the existing parking structure would occur in phases with the installation of temporary lagging and shoring. All construction debris would be directed to the pool/courtyard area for export. A ramp would be built with access to Francisco Street to allow trucks and equipment to drive into the demolition and excavation area. Trucks would be queued along Francisco Street, no more than five trucks at a time. As described in the project design features, a sound barrier would be built along Francisco Street to reduce the construction noise.

Detailed calculations data sheets, including assumptions and procedures, are included in Appendix IV.C.1. The estimated noise levels represent a conservative scenario, because construction activities were assessed as if they were occurring along the perimeter of the Project Site (e.g., shoring within the excavated pit of the subterranean garage), whereas construction would typically occur throughout the site and at a further distance from the affected receptor. In addition, the noise receptors that are located further away from the Project Site would experience less construction noise, because sound diminishes as a function of not only distance from the source (which was taken into consideration in the calculations in Table IV.C-12), but also due to intervening buildings between the source and receiver (which were not taken into consideration).

As indicated in Table IV.C-12, the estimated construction-related noise levels at all off-site locations would be at or below the existing daytime ambient noise levels, with the exception of locations R0, R1, R2, and R3, which are immediately adjacent to the Project Site. Furthermore, at the receptors located 1,000 feet or greater from the Project Site (R6, R8, R9, R12 through R16, and R18), construction-related noise would be masked by the existing ambient noise levels. Although the construction-related noise would exceed the daytime ambient noise levels by up to 15 dBA at locations R0, R1, R2, and R3, these locations are not considered noise sensitive based on the City’s definition or noise-sensitive uses,30 because these locations contain commercial land uses and limited outdoor uses (i.e., outdoor plazas). Noise levels for R0, R1, R2, and R3 are provided for informational purposes only. Therefore, Project impacts associated with construction-related noise impacts would be less than significant.

30 L.A. CEQA Thresholds Guide, Section B. Air Quality, 2006, page B.2-.4.



Table IV.C-12 Construction Noise Levels for the Project

Location

Distance to Project’s Nearest

boundary of Construction

Site (ft)a

Measured Existing Daytime Ambient

Levels, (dBA)

Estimated Construction Noise Levels by Construction Activity Hourly Leq (dBA)

Significance Threshold

(dBA)b Sensitive

Receptor? Site

Demolition Shoring /

Excavation Garage

Construction

Onsite Utilities/

Landscape

Hotel/ Office Buildings

Construction Offsite Utilities

R0 12 67.6 94 94 89 85 85 88 n/a n/a R1 80 71.4 85 83 81 83 82 84 n/a No R2 75 73.8 86 84 82 83 82 85 n/a No R3 85 70.9 85 82 80 82 81 83 n/a No R4 500 64.5 64 62 60 62 63 59 70 Yes R5 700 72.3 61 59 57 59 60 56 77 Yes R6 1,000 70.8 48 46 44 46 47 43 76 Yes R7 800 66.2 60 58 56 58 59 55 71 Yes R8 1,300 72.7 41 39 37 39 40 36 78 Yes R9 1,500 70.0 40 38 36 37 39 34 72 Yes R10 800 70.6 50 48 46 48 49 45 76 Yes R11 700 73.4 51 49 47 49 50 46 78 Yes R12 1,200 68.5 42 39 37 39 41 36 74 Yes R13 1,700 62.9 39 36 34 36 38 33 68 Yes R14 5,000 56.0 29 27 25 27 28 24 61 Yes R15 6,000 62.5 28 26 24 25 27 23 68 Yes R16 3,800 57.8 32 29 28 29 31 26 63 Yes R17 450 65.9 55 53 51 53 53 50 71 Yes R18 2,200 58.2 36 34 32 34 35 31 63 Yes a Represent shortest distance between the receptor and construction area. Estimated based on Google Earth Map. b Significance threshold is equal to ambient plus 5 dB (dBA values are rounded up to the nearest whole number). n/a – not applicable as these receptors are not considered noise sensitive per L.A. CEQA Thresholds Guide.

ft = feet Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).



2. Off-Site Noise Sources (Construction Trucks)

In addition to on-site construction noise sources, other major noise sources would include off-site noise sources such as construction trucks (delivery, concrete mix, and haul trucks) and construction worker vehicles. Typically, construction trucks generate higher noise levels than construction worker-related traffic especially since construction workers arrive at the Project Site before the morning commute peak period (before 6:00 A.M) and would leave the Project Site during the afternoon commute peak period (after 4:00 P.M.). In addition, the construction worker commute program for the Project assumes that 20 percent of the workers would use public transit to commute to the site, 40 percent would drive alone, and 40 percent would carpool (two workers per vehicle). Based on the Project’s construction plan and the transportation study prepared for the Project, the peak period of truck movements would occur during site excavation when there would be up to 32 haul truck trips per hour (on an average hourly basis, assuming a uniform distribution of trips over the 10-hour work day). The average haul truck traffic would be 320 haul trucks trips (entering and exiting the Project Site) per day. During Project Site excavation, the staging area for the haul trucks would be along Wilshire Boulevard and 7th Street.

Haul trucks and delivery trucks would also access the site during other construction phases of the Project (e.g., demolition and building construction). During construction of the building foundation/garage (e.g., concrete pour), approximately 28 concrete mix trucks (56 trips) per hour would be required. Large concrete pours would occur on the weekends with the staging area along Figueroa Street. As for construction delivery trucks, peak traffic would occur during the construction of the garage and would last approximately 36 months. During this period, a total of approximately 72 truck trips would occur per day and staging for typical delivery trucks would occur along Francisco Street with no more than five trucks queuing at a time. On an average hourly basis, assuming a uniform distribution of trips over the 10-hour workday, these daily delivery truck trip totals would translate to approximately seven trips per hour, which is significantly less than the number of haul trucks during site excavation. Therefore, Project construction-related haul trucks during excavation were evaluated to provide the most conservative assessment of off-site construction noise impacts.

Trucks would generally enter and exit the Project Site via Francisco Street, Wilshire Boulevard, 7th Street, Figueroa Street, via 5th and 6th Streets, to James M. Wood Boulevard to the Harbor Freeway. There are noise sensitive uses (i.e., hotel/residential uses on Figueroa Street), which have direct line-of-sight to the construction truck route. Hourly average noise generated by construction trucks along the roadways leading to the Project Site would be approximately 67 dBA (Leq) during site demolition and excavation and 69 dBA (Leq) during building construction (concrete pour of foundation/garage), which would be consistent with the existing daytime hourly ambient noise levels of 66 – 74 dBA (measured ambient at R2, R8, R9, and R17) along the truck routes. In addition, construction truck traffic, with the exception of those rare occasions where continuous concrete pouring is required, would not occur during the noise-sensitive late evening and nighttime hours. As such, significant noise impacts would not be expected from off-site construction traffic and impacts would be less than significant.



3. Groundborne Vibration

Construction activities can generate varying degrees of groundborne vibration, depending on the construction procedures and the 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, to slight damage at the highest levels. Unless heavy construction activities are conducted extremely close to the neighboring structures, groundborne vibrations from construction activities rarely reach the levels that damage structures.

The FTA has published standard vibration velocity levels for construction equipment operations. The reference vibration levels (PPV) for construction equipment pieces that would be used during Project construction are listed in Table IV.C-13 (Construction Vibration Impacts). The nearest off-site above ground building structures include the office tower (1000 Wilshire Boulevard), located approximately 60 feet west of the Project Site. If Francisco Street is vacated, excavation for the proposed subterranean parking garage could extend underneath Francisco Street within two feet of the sidewalk, on the west side of Francisco Street. The estimated vibration levels due to construction equipment at 12 feet distance are included in Table IV.C-13. Construction vibration impacts are based on the instantaneous peak vibration level produced by each of the construction equipment. With regard to the construction activities proposed by the Project, the highest levels of groundborne vibration would be generated primarily during site demolition and grading/excavation activities on site.

Table IV.C-13 Construction Vibration Impacts

Construction Equipment (major powered equipment)

Reference Vibration Levels at 25 feet, PPV ( inch per

second)a

Estimated Vibration Levels at Indicated Distance, PPV ( inch per second)b

12 feet c

(Nearest Off-Site Building Structure)

75 feet (Nearest Off-Site Historic Building

Structure) Large Bulldozer 0.089 0.268 0.017 Caisson Drilling 0.089 0.268 0.017 Loaded Trucks 0.076 0.229 0.015 Jackhammer 0.035 0.105 0.007 Small Bulldozer 0.003 0.009 0.001 a FTA, Transit Noise and Vibration Impact Assessment, Table 12-2, 2006. b PPV at distance D = PPVref x (25/D)1.5. c 12 feet is the shortest distance between Project Site and off-site building structures (R0).

Source: FTA, 2006, Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).



Groundborne vibration decreases rapidly with distance. As indicated in Table IV.C-11, vibration velocities from typical heavy construction equipment operations that would be used during construction of the Project would range from 0.003 to 0.089 inch/sec (PPV) at 25 feet from the equipment based on the FTA data. Project construction would not use pile driving methods and as such, pile driving vibration is not included in this construction vibration analysis. At 12 feet (the distance between the closest off-site above ground building (R0) and the Project Site construction area) from the source of activity, vibration velocities would be reduced to 0.009 to 0.268 inch per second (PPV). The construction trucks along Francisco Street would generate vibration levels up to 0.076 inch/second (PPV) at the outside of and adjacent to the nearest off-site building. As each of these values is below the 0.5 inch per second (PPV) significance threshold, vibration impacts associated with construction would be less than significant at the nearest off-site building structure.

The Mullen Building/Historic Fire Station No. 28 is located approximately 75 feet from the Project Site, at 644 South Figueroa Street. The Project construction activities would generate vibration levels up to 0.017 inch per second (PPV) at the Historic Fire Station No. 28, as indicated in Table IV.C-13. The estimated vibration level is below the significance threshold of 0.25 inch per second (PPV) for historic buildings. As such, construction vibration impacts would be less than significant.

In addition to the above ground off-site building structures, the existing Metro Red Line subway tunnels are located underneath 7th Street adjacent to the Project Site. The Project’s excavation activities for the construction of the proposed subterranean garage would likely occur within five feet from existing Metro tunnel wall structure. The Metro Red Line subway tunnels would be exposed to vibration levels up to 1.0 inch per second (PPV) during site excavation when the construction activities are within five feet of the Metro tunnel structures. The estimated ground vibration level would exceed the significance threshold of 0.5 inch per second (PPV). Therefore, construction-related groundborne vibration impacts to the Metro tunnel near the Project Site would be potentially significant. Therefore, mitigation measure 4 is included in this EIR to reduce the potential vibration impacts to less than significant. As the excavation construction activities move further away from the Metro tunnel structures (greater than five feet), the Project’s construction induced-ground vibration would be below the significance threshold of 0.5 inch per second (PPV).

In addition to groundborne vibration generated by operation of construction equipment machinery, groundborne vibration would be generated from construction debris, falling onto the ground during site demolition activities. The demolition of the existing Wilshire Grand Hotel and Centre would proceed from the top level down. Soft items, such as drywall, insulation, adhesives, etc, would be removed using bobcat tractors and deposited via a debris chute to one collection point (e.g. existing pool/courtyard area). Hard items, such as concrete and steel material would be taken down using excavators, backhoes, and/or a crane. Any hard items that weigh approximately 2,000 pounds or greater would be lower to the ground using construction crane equipment.31 Occasionally, smaller construction pieces (i.e., less than 2,000 pounds) may be dropped down (from various floor heights up to the 16th floor) to the ground elevation at

31 Turner Construction, emails dated 3/15/2010 and 3/24/2010.



a predetermined collection point. Groundborne vibration generated by the impact from the construction debris falling on to the collection point would vary depending on: a) the weight of the debris; b) the height of the drop; and c) the distance from impact point to the receptor of the ground vibration.

Table IV.C-14 presents the estimated groundborne vibration levels due to falling debris and as a function of drop height, weights, and distances from the point of impact to the receptor of the ground vibration. The highest vibration level is anticipated to occur when the heaviest debris (i.e., estimated 2,000 pounds) is dropped from the height of 16th floor and lands near the Project property line. As indicated by Table IV.C-14, the groundborne vibration generated by the impact from construction debris would reach maximum 0.65 inch per second (PPV) at the nearest off-site building (R0), which would exceed the 0.5 inch per second (PPV) significance threshold. At a distance of 100 feet, from the point of impact the groundborne vibration would be attenuated to below the 0.5 inch per second (PPV) threshold. Construction debris drop would occur approximately 165 feet from the Mullen Building/Historic Fire Station No. 28 (R2) and would generate vibration levels up to 0.27 inch per second (PPV). The estimated vibration levels at R2 would exceed the significance threshold of 0.25 inch per second (PPV) for historic buildings. Therefore, vibration impacts due to the construction debris falling would be significant at the nearest above-grade buildings.

Table IV.C-14 Estimated Groundborne Vibration due to Construction Debris Falling

Drop Height,a feet

Debris Drop

Weight, pounds

Estimated Vibration Levels at distances from Drop Impact Point, inch per second (PPV)

75 feet (Approx.

distance to R0)

100 feet (Approx.

distance to R1)

125 feet (Approx.

distance to R3)

165 feet (Approx.

distance to R2)

192 ft (16th Floor) 2,000 0.65 0.47 0.37 0.27 1,500 0.56 0.41 0.32 0.24 1,000 0.46 0.33 0.26 0.19 120 ft (10th Floor) 2,000 0.51 0.37 0.29 0.21 1,500 0.44 0.32 0.25 0.19 1,000 0.36 0.26 0.21 0.15 24 ft (2nd Floor) 2,000 0.23 0.17 0.13 0.10 1,500 0.20 0.14 0.11 0.08 1,000 0.16 0.12 0.09 0.07 a Estimated average of 12 feet high per floor. 16th floor is the highest elevation with 10th floor representing the mid level elevation and the 2nd floor is the shortest drop elevation that debris from demolition activities may be dropped. Source: Acoustical Engineering Services, 2010

The Metro tunnel is located approximately 50 feet below grade (underneath 7th Street). The vibration generated by falling construction debris’s impact onto the collection point (e.g. the pool/courtyard area) would travel through the ground strata in vertical and horizontal directions. While the majority of the vibration energy would travel as surface wave (travel in the horizontal direction), some of the impact energy would also propagate downward (vertical direction). Technical vibration information provided by



Caltrans indicates that with most of the vibration energy (about 67 percent) is transmitted as surface wave (Rayleigh Wave) near the surface of the ground.32 The remaining energy (about 33 percent) would be transmitted through the ground in a vertical direction. It is estimated that construction debris falling during the site demolition would generate vibration levels up to 0.43 inch per second (PPV) at the Metro tunnel. The estimated vibration levels would be below the significance threshold of 0.5 inch per second.

Table IV.C-15 provides the estimated distance at which the construction equipment induced ground vibration levels would be below the threshold of human perception (from FTA). As indicated in Table IV.C-15, at a distance of 140 feet or greater, Project related construction activities using large equipment such as a large bulldozer or caisson drilling would be below the threshold of perception. For smaller equipment, such as a jackhammer or small bulldozer, the groundborne vibration created by this equipment would be below the threshold of perception at a distance of approximately 75 feet.

Table IV.C-15 Construction Vibration Impacts – Building Damage

Construction Equipment

(major powered equipment)

Reference Vibration Levels at 25 feet, a

VdB

Threshold of Perception, b

VdB

Distance at which Vibration would be below Threshold of

Perception, feet

Large Bulldozer 87 65 140 Caisson Drilling 87 65 140 Loaded Trucks 86 65 130 Jackhammer 79 65 75 Small Bulldozer 58 65 15 a FTA, Transit Noise and Vibration Impact Assessment, 2006, Table 12-2. b FTA, Transit Noise and Vibration Impact Assessment, 2006, Section 7.1.2. Source: FTA, 2006, Acoustical Engineering Services, 2010


Once the Project is operational, on- and off-site noise levels could increase with contributions from Project-related on-site noise sources including building mechanical equipment, parking structure use, and amenities located outdoors, the helistop (helicopter), and off-site noise sources including Project-generated traffic. These potential noise impacts are discussed in the following paragraphs.

1. On-Site Noise Sources Noise

(a) Building Mechanical Equipment

The Project would include building services mechanical equipment to condition and ventilate the indoor air environment, such as air handling units, cooling towers, chillers, and exhaust-air fans to support the 32 Transportation- and Construction-Induced Vibration Guidance Manual, Caltrans, 2004.



intended functions of the Project. The mechanical equipment would be enclosed and likely located within a mechanical room/central plant in the subterranean garage or the podium level, and the location of the cooling towers is proposed for the rooftop of the office building or the podium.

The ambient noise levels surrounding the Project Site ranged from 71.7 to 76.1 dBA CNEL (ambient noise at R0, R1, R2, and R3). Therefore, to ensure the Project mechanical equipment noise would not exceed the significance threshold (an increase of maximum 3 dBA CNEL) at these off-site locations, the noise generated by the Project’s mechanical equipment would be limited, as a project design feature, to a maximum of 63 dBA Leq (70 dBA CNEL) at the Project property line. Limiting the Project’s mechanical equipment noise to 70 dBA CNEL would result in a maximum increase of 2.3 dBA at the nearest receptor (R0), from 71.7 dBA CNEL to 74 dBA CNEL, which would be below the Project significance threshold of a 3 dBA CNEL increase. Furthermore, the Project mechanical equipment noise levels at noise-sensitive receptors that are located farther away would be lower due to additional sound attenuation resulting from the greater distance and intervening buildings. Additionally, the design and construction of the Project would be required to comply with the Noise Insulation Standards of Title 24 of the CCR, which ensure an acceptable interior noise environment (45 dBA) for the hotel and residential uses of the Project. Therefore, with implementation of the project design features, noise impacts associated with mechanical equipment would be less than significant.

(b) Parking Facility

The Project includes an eight level subterranean parking structure. The subterranean parking facility (fully enclosed structure) could be accessed from 7th Street and Francisco Street. Various noise events would periodically occur from the parking facilities including activation of car alarms, sounding of car horns, slamming of car doors, and tire squeals. Automobile movements would comprise the most continuous noise source and would generate a noise level of approximately 65 dBA at a distance of 25 feet.33 Car alarm and horn noise events would generate maximum noise levels of as high as 75 dBA at a reference distance of 25 feet. The subterranean parking facility would be fully shielded to the exterior and thus, would provide effective noise shielding to all on-site and off-site noise-sensitive receptors. Therefore, Project noise impacts associated with the subterranean parking facility would be less than significant.

In addition, the Project parking operation would include valet parking services located on the south side, along 7th Street. Typically, valet parking related noise levels are lower than those generated by the parking circulation. Noise sources associated with a use of valet drop off area include low speed traffic and car door closing. Noise levels generated by the valet parking area would be lower than the existing traffic noise and ambient noise levels, and would be similar to the noise levels generated by the existing valet parking service. Therefore, Project noise impacts associated with valet parking would be less than significant.

33 Based on actual measurements at various parking structures (refer to Appendix IV.C-1).



(c) Loading and Trash/Recycling Areas

The loading docks and trash/recycling areas for the Project would be located within the structure (refer to Figure II-5, Conceptual Plan – Level 1, in Section II., Project Description). Delivery and trash/recycling trucks would enter the structure from Francisco Street, and all loading/unloading would occur within the structure; none of these activities would occur outside of the proposed structure. Sources of noise associated with loading/unloading activities for the Project include engines, doors opening and closing, items being loaded into or unloaded out of trucks, dumping of garbage/recycling bins, and back-up beeping. Noises associated with these sources are temporary and intermittent. All noises associated with the loading/unloading activities would be attenuated from off-site sources by the walls and other infrastructure of the proposed structure. In the event that the loading docks and trash/recycling areas would be located outside of the enclosed parking structure, all outdoor loading docks and trash/recycling areas shall be fully or partially enclosed such that the line-of-sight between these noise sources and any adjacent noise sensitive receptor shall be obstructed. No off-site sensitive receptors are located near the western boundary of the Project Site. Additionally, the design and construction of the Project would be required to comply with the Noise Insulation Standards of Title 24 of the CCR, which would ensure an acceptable interior noise environment (45 dBA) for the hotel and residential uses of the Project. For these reasons, no substantial noise increases associated with the loading docks and trash/recycling areas would occur and Project impacts would be less than significant.

(d) Outdoor Services

The Project would include an outdoor pool and bar, which would be located at the top of the podium structure or the rooftop of the hotel building, and an outdoor plaza, which would be at street level and oriented toward the corner of 7th Street and Figueroa Street. In addition to noise from use and activities, other potential noise associated with the outdoor pool, bar, and plaza would include amplified program sound (music or other sound broadcast through a loudspeaker system). This sound could be broadcast during the hours of 7:00 a.m. to 2:00 a.m. and could include, but is not limited to, music, television sound, and announcements intended to be heard by patrons in the immediate vicinity of the outdoor pool and bar and the outdoor plaza. The closest off-site noise sensitive receptors to the outdoor pool and bar area are the multi-family residential receptors located approximately 500 feet to the northwest (R4) of the Project Site. The existing ambient noise level at location R4 was 68.6 dBA CNEL. Therefore, the Project includes a project design feature (discussed previously) that would ensure the amplified program sound would not exceed the significance threshold (an increase of 3 dBA CNEL) at the off-site noise-sensitive receptors by limiting the amplified program sound planned for the outdoor pool and bar areas to a maximum 80 dBA (Leq (hr)) at a distance of 50 feet from the amplified sound system. The closest off-site noise sensitive receptor to the street level outdoor plaza would be the Jonathan Club (R17), which is located approximately 450 feet north of the Project Site. The existing ambient noise level at location R17 was 70.2 dBA CNEL. Similar to the outdoor pool and bar areas, the amplified program sound at the outdoor plaza would be designed to have a noise limit of a maximum 70 dBA (Leq [hr]) at a distance of 50 feet from the amplified sound system to ensure that the amplified program sound would not exceed the significance threshold (an increase of 3 dBA CNEL) at the off-site noise-sensitive receptor.



In addition to the amplified program sound, there would be sound generated by the patrons at the outdoor pool and bar areas. It is anticipated that there would be up to 500 people gathering around the outdoor pool and bar areas at any given time. Reference noise levels of 75 dBA and 71 dBA (Leq at 3.3 feet distance) for a male and female speaking in loud voice, respectively, were used for the patrons’ noise analysis.34 In order to assess a typical noise scenario, it was assumed that up to 50 percent of the patrons (50 percent male and 50 percent female) would be talking at the same time. Based on distance attenuation and noise reduction provided by the podium or rooftop parapet which would be of solid panel construction according to the previously described project design features, noise from patrons talking at the nearest off site noise-sensitive receptor (R4) is estimated to reach 44 dBA Leq. The overall noise from the outdoor services (including both amplified program sound and patrons talking sound) at the nearest off-site noise sensitive receptor (R4) would be 65 dBA CNEL, which would be below the existing ambient noise level of 68.6 dBA CNEL.

With respect to all noise sources generated by the outdoor services, as mentioned previously, the design and construction of the Project would be required to comply with the Noise Insulation Standards of Title 24 of the CCR, which ensure an acceptable interior noise environment (45 dBA) for the hotel and residential uses of the Project. Therefore, with implementation of the project design features, noise impacts associated with outdoor services would be less than significant.

2. Helistop

The Project would include a helistop on the rooftop of the new office building. Heliport Consultants has provided a detailed report regarding the helistop operations including; helicopter flight paths, type of helicopters, helicopter flight profiles, and daily operations (included in Appendix IV.C.2). The helistop would be located at the rooftop of the 65-story office building, at an elevation of approximately 1,368 feet relative to mean sea level (msl)35 or 1,090 feet relative to local grade elevations. The Project includes a project design feature that requires the Project’s helicopters to use the recommended flight paths as described in the Heliport Consultant Report (Appendix IV.C.2), unless a different path is required for safety precautions. In accordance with this project design feature the helistop would be accessed along two different proposed flight paths, one for departure and the other for arrival. The arrival (approach) flight path would generally follow the Harbor Freeway from the north and the departure flight path would follow the Harbor Freeway to the south, as illustrated in Figure IV.C-2 (Helicopter Flight Tracks). The location of the Project’s office building allows the helicopter to approach and depart the helistop along a flight path that follows the freeway in a northeast and southwest direction and avoids traveling over any residential and noise-sensitive areas, and these flight paths would be assured by implementation of project design features.

34 Handbook of Acoustical Measurements and Noise Control, Table 16.1, Cyril M. Harris, Third Edition, 1991. 35 Mean sea level (msl) is the level of the surface of the sea at its mean position midway between high and low

tide.

Arrival Flight Track

Departure Flight Track

Proposed Helipad Location

BIXE

L ST

REET

LUCA

S AV

ENUE

WIT

MER

STR

EET

GARL

AND

AVEN

UE

110

HARBOR FREEWAY

BEAUDY AVENUE

ST P

AUL

AVEN

UE

BOYL

STON

STR

EET

XX

X

Building A Building B

Source: Acoustical Engineering Services, 2009.

Figure IV.C-2Helicopter Flight Tracks

Scale (Feet)

0 400 800

Legend

Project Site

Helicopter Departure Flight Track

Helicopter Arrival Flight Track

Propose Buildings A and B

Helipad Location

5TH STREET

WILSHIRE BOULEVARD

WILSHIRE BOULEVARD

7TH STREET

7TH STREET

LINWOOD AVENUE

JAMES M. WOOD BOULEVARD

8TH STREET

8TH STREET

FRANCIS

CO STR

EET

FIGUER

OA STR

EET

FLOW

ER S

TREE

THOPE

STR

EET

OLIVE

STR

EET

GRAND AVE

NUE

8TH STREET

9TH STREETBROADW

AY

HILL S

TREE

T

6TH STREET

5TH STREET

3RD STREET

4TH STREET

OLYMPIC BOULEVARD

11TH STREET

CHICK HEARN COURT

GEOR

GIA

STRE

ET

SPRIN

G STR

EET



It is difficult to predict the number of helicopter operations since this facility would be used on an on-demand basis and would not have regularly scheduled operations. However, it is estimated that the charter operation of the helistop would provide service as follows: an average of two flights per day, occurring on average five days per week and 20 days during a 30-day month. Based on the average of two flights per day over the 20 days, it is estimated that the helistop would provide a maximum of 480 flights per year36 Notwithstanding the number of landings per day, all flights, on average, are expected to be distributed over 24 hours. Of the estimated two flights per day, 80 percent of the flight would occur during daytime hours (7:00 a.m. to 7:00 p.m.), 15 percent during the evening hours (7:00 p.m. to 10:00 p.m.) and five percent during the nighttime hours (10:00 p.m. to 7:00 a.m.). Therefore, on an operation-day with two flights, the flight distribution per hour would be; 1.6 flights during daytime hours, 0.3 flight during the evening hours, and 0.1 flights during nighttime hours. The helistop could accommodate various helicopter types such as the single engine Bell 206L, and Eurocopter AS350 Astar, as well as the twin engine Agusta 109, and the Sikorsky S76. Table IV.C-16 (Helistop Helicopter Operation) provides the summary of the helicopter operations at the helistop, distributed by helicopter types and hours.

Table IV.C-16 Helistop Helicopter Operation

Helicopter Type

Flights/ Year

Flights/ Day

Flights per Time Perioda Daytime (7 a.m. to

7 p.m.)

Evening (7 p.m. to 10 p.m.)

Nighttime (10 p.m. to

7 a.m.) Bell 206L 236 0.98 0.7840 0.1470 0.0490 AS 350 236 0.98 0.7840 0.1470 0.0490 Sikorsky S76 2 0.01 0.0080 0.0015 0.0005 Agusta A109 6 0.03 0.0240 0.0045 0.0015

Total Flights 480 2.00 1.6000 0.3000 0.1000 Notes: a A helicopter flight includes one departure and one arrival, two operations. Source: Heliport Consultants, 2010 (refer to Appendix IV.C.2), Acoustical Engineering Services, 2010 (refer

to Appendix IV.C.1).


Table IV.C-17 (Summary of Helistop Noise Impacts – Land Use Compatibility Analysis ) presents the predicted CNEL noise levels generated by the proposed helistop operations at the 19 off-site noise receptors. As indicated on Table IV.C-17, the helistop operations would generate noise levels from 26.0 dBA CNEL at R15 (approximately 6,000 feet from the Project Site) to 44.7 dBA CNEL at R1 and R2 (adjacent to the Project Site), but would not contribute to a measurable increase in the ambient noise levels at any receptor location. The relatively low 24-hour average (CNEL) noise levels associated with these operations are reflective of the relative infrequency of the flights and the predominance of flight

36 A helicopter flight includes one departure and one arrival, two operations.



occurrence during daytime hours. The existing ambient noise levels in the vicinity of the Project Site and along the helicopter flight paths are well above 65 dBA CNEL. The predicted helistop operations noise at the off-site noise receptors would be a minimum of 23.6 dBA below the existing ambient noise levels (in terms of CNEL). Therefore, the helistop operations would cause no measurable increase over the existing ambient noise levels (CNEL levels) at the noise sensitive receptors, and the noise increase associated with the helistop operations would not exceed the significance threshold of a 1.5 dBA increase. In addition, as mentioned previously, the design and construction of the Project would be required to comply with the Noise Insulation Standards of Title 24 of the CCR, which ensure an acceptable interior noise environment (45 dBA) for the hotel and residential uses of the Project. As such, from a land use compatibility standpoint, with implementation of the project design features, the Project would not result in incompatible residential uses being located within the 65 dBA CNEL contour or above. Therefore, the noise impacts associated with the proposed helistop operations would be less than significant.

Table IV.C-17 Summary of Helistop Noise Impacts – Land Use Compatibility Analysis

Location

Longitudinal Distance

from Project Site, feet

Predicted Helistop

Operations Noise

Levels,a CNEL (dBA)

Existing Ambient

Noise Levels,b CNEL (dBA)

Existing Ambient

Plus Project Helistop

Operations,CNEL (dBA)

Increase in Ambient

Noise Levels due to Helistop Operations

Significance Threshold,c

CNEL (dBA)

Sensitive Receptors?

R0 60 44.1 71.7 71.7 0 n/a No R1 80 44.7 72.0 72.0 0 n/a No R2 75 44.7 76.1 76.1 0 n/a No R3 85 44.2 72.1 72.1 0 n/a No R4 500 42.9 68.6 68.6 0 n/a Yes R5 700 41.5 75.0 75.0 0 1.5 Yes R6 1,000 40.4 72.2 72.2 0 1.5 Yes R7 800 41.7 68.9 68.9 0 1.5 Yes R8 1,300 40.9 74.1 74.1 0 1.5 Yes R9 1,500 37.8 75.4 75.4 0 1.5 Yes R10 800 42.6 71.1 71.1 0 1.5 Yes R11 700 42.8 73.7 73.7 0 1.5 Yes R12 1,200 39.6 71.0 71.0 0 1.5 Yes R13 1,700 38.0 66.2 66.2 0 1.5 Yes R14 5,000 30.8 62.9 62.9 0 1.5 Yes R15 6,000 26.0 63.4 63.4 0 1.5 Yes R16 3,800 32.2 62.1 62.1 0 1.5 Yes R17 450 43.9 71.1 71.1 0 1.5 Yes R18 2,200 36.8 60.4 60.4 0 1.5 Yes Notes: a Predicted noise level at ground level. b From Table IV.C-7. c Maximum of 1.5 dBA increase in ambient noise levels in terms of CNEL.



Table IV.C-17 Summary of Helistop Noise Impacts – Land Use Compatibility Analysis

Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).

(b) Sleep Disturbance and Speech Interference

In addition to the land use compatibility analysis, the INM model calculates the noise levels generated during a single aircraft event in terms of SEL and Lmax. The single event noise analysis provides the average noise levels that would be experienced at a receptor location resulting from a single helicopter event, over the course of the event, regardless of the number of flights per day. The AS350 and Bell 206L helicopters represent 98 percent of the anticipated helistop operation. However, the Bell 206L generates higher noise levels than the AS350. Therefore, the helicopter type Bell 206L was used to assess the single event noise levels.

Table IV.C-18 (Helicopter Single-Event Noise Analysis [SEL]) presents the predicted SEL from the Bell 206L at the off-site noise receptor locations. Noise levels were calculated at the ground and upper levels of the high-rise buildings, in the vicinity of the receptor location, to quantify the helicopter noise at the lower and upper levels of the affected buildings. As indicated in Table IV.C-18, the predicted SEL levels at the ground level at all receptor locations would be below the 94 dBA SEL threshold (for residential, hotel, and hospital uses), ranging from 72 dBA SEL at R15 to 91 dBA SEL at R1, R2, and R3. At the upper levels, with the exception of the existing office buildings at R0, R1, R2 and R3, which are not noise sensitive receptors, the predicted SEL levels are also below the 94 dBA SEL threshold. At all off-site residential, hotel, and hospital locations where potential sleep disturbance could occur, predicted SEL levels would be below the 94 dBA SEL threshold. Therefore, potential impacts due to single-event noise from the proposed helistop would be less than significant.

With respect to the school sites, the Bell 206L would generate maximum noise levels of 54 dBA Lmax and 68 dBA Lmax at noise receptor locations R15 (9th Street Elementary School) and R18 (Miguel Contreras Learning Center and Evelyn Thurman Gratts Elementary School), respectively. The predicted Lmax levels at the school sites would be below the 80 dBA Lmax threshold (for school uses). Therefore, noise impacts due to Helistop operations would be less than significant.

3. Off-Site Traffic (Mobile Sources)

Future roadway noise levels were calculated along 28 off-site roadway segments in the vicinity of the Project Site. According to the Project transportation study, the Project is expected to generate 3,624 net new daily trips (Average Daily Trips) by the Project’s anticipated full occupancy year of 2020.37 As indicated in the Project traffic study, Project-related traffic would increase the traffic volumes along the

37 Gibson Transportation Consulting Inc, 2010 (refer to Appendix IV.B).



Table IV.C-18 Helicopter Single-Event Noise Analysis (SEL)

Location

Longitudinal Distance from Project Site,

feet

Predicted Helicopter (Bell 206L) Single-Event Noise

Levels, SEL (dBA)

Land Use Significance Threshold

Sensitive Receptor?

At Ground Level

At Building Roof Level

R0 60 90 93 Commercial --a No R1 80 91 94 Commercial --a No R2 75 91 95 Commercial --a No R3 85 91 96 Commercial --a No R4 500 89 89 Residential/ Office 94 Yes R5 700 88 88 Residential/ Office 94 Yes R6 1,000 86 88 Residential/

Commercial 94 Yes

R7 800 88 90 Hotel/ Commercial 94 Yes R8 1,300 86 89 Hotel/ Commercial 94 Yes R9 1,500 84 84 Hotel/ Residential/

Commercial 94 Yes

R10 800 89 90 Residential/ Commercial 94 Yes

R11 700 89 90 Hotel/ Commercial 94 Yes R12 1,200 86 86 Residential/

Commercial 94 Yes

R13 1,700 84 84 Hospital 94 Yes R14 5,000 76 --b Residential/

Commercial 94 Yes

R15 6,000 72 --b School/ Commercial --a Yes R16 3,800 77 --b Residential/

Commercial 94 Yes

R17 450 90 91 Hotel 94 Yes R18 2,200 82 --b School/

Residential 94c Yes

Notes: a Not applicable to Commercial and School land uses. b Not Calculated for buildings with fewer than three stories. c Significance threshold is applicable to the residential uses at R18, not applicable to the school uses. n/a – Not calculated for buildings with less than three stories. Source: Acoustical Engineering Services, 2010.

28 study roadway segments over existing and future without Project. The increase in roadway traffic was assessed to determine if any traffic-related noise impacts would result from the Project. The Project-related traffic noise impact was determined by comparing the increase in noise levels from the “future without project” (2020 baseline) to “future with project” (2020 baseline plus Project-related traffic) to the significance threshold. The 2020 baseline condition includes existing traffic volumes plus traffic volumes



from future growth and known related projects volumes. The “future with project” includes the 2020 baseline plus the Project-related traffic. Table IV.C-19 (Off-Site Roadway Traffic Noise Impacts) provides a summary of the off-site roadway noise analysis. However, it should be noted that the calculated CNEL levels are conservative as these predicted noise levels are calculated in front of the roadways and do not account for the presence of any sound barriers or intervening structures. As shown in Table IV.C-19, the Project would result in a maximum of a 2.1 dBA increase in traffic noise along Francisco Street between 7th Street and Wilshire Bouelvard. At all other study roadway segments, the increase due to Project-related traffic would be lower (less than 1.0 dBA), as Project-related traffic would disperse to various nearby roadways away from the Project Site. The incremental changes in Project-related traffic noise level would be negligible in the existing exterior noise environment. In addition, the change would be below the 3 dBA CNEL significance threshold, which is considered to be an increase barely perceptible to the human ear. Therefore, for all the reasons discussed previously, off-site traffic noise impacts associated with the Project would be less than significant.

Table IV.C-19 Off-Site Roadway Traffic Noise Impacts

Roadway Segment

Distance to Roadway

Centerline, feet

Calculated Traffic Noise Levels,a CNEL

Adjacent Land Uses

Increase in Noise Levels due to

Project, CNEL

2020 Baseline (Without Project)

2020 With

Project Glendale Blvd.

- Between Temple St. and Beverly Blvd. 35 73.9 73.9 Commercial 0.0


25

66.5

68.6

Commercial

2.1

Lucas Ave. - Between 3rd St. and 6th St. 25 71.2 71.2 Residential/

School 0.0

- Between 6th St. and Wilshire Blvd. 25 69.7 69.9 Hospital 0.2

Wilshire Blvd. - Between Alvarado St. and Lucas Ave. 40 72.4 72.5 School 0.1 - Between Lucas Ave. and Beaudry Ave. 40 72.3 72.4 Residential 0.1 - Between Francisco St. and Figueroa St. 40 71.8 72.5 Hotel/Office 0.7 - Between Figueroa St. and Grand Ave. 40 69.6 69.8 School 0.2

6th St. - Between Figueroa St. and Flower St. 35 69.9 69.9 Commercial 0.0 - Between Flower St. and Olive St. 35 69.2 69.2 Commercial 0.0 - East of Olive St. 35 70.7 70.7 Park 0.0

7th St. - Between Alvarado St. and Bixel St. 35 68.4 68.5 Residential/ 0.1



Table IV.C-19 Off-Site Roadway Traffic Noise Impacts

Roadway Segment

Distance to Roadway

Centerline, feet


Adjacent Land Uses

Increase in Noise Levels due to

Project, CNEL


2020 With

Project School

- Between Bixel St. and Francisco St. 35 68.6 68.9 Residential 0.3 - Between Francisco St. and Figueroa St. 35 68.9 69.5 Hotel/Office 0.6 - Between Figueroa St. and Grand Ave. 35 69.0 69.5 Hotel 0.5 - Between Grand Ave. and Alameda Blvd. 35 68.7 69.0 Religious 0.3

Figueroa St. - Between 3rd St. and 5th St. 40 73.9 74.1 Hotel 0.2 - Between 5th St. and Wilshire Blvd. 40 74.4 74.7 Office 0.3 - Between Wilshire Blvd. and 7th St. 40 73.0 73.1 Hotel/Office 0.1 - Between 7th St. and Olympic Blvd. 40 72.2 72.2 Residential 0.0 - Between Olympic Blvd. and Pico Blvd. 40 72.2 72.3 Residential 0.1

Flower St. - Between 3rd St. and 5th St. 40 71.4 71.6 Hotel 0.2 - Between 5th St. and Wilshire Blvd. 40 71.2 71.3 Office 0.1 - Between Wilshire Blvd. and 8th St. 40 72.0 72.1 Office 0.1 - South of 8th St. 40 71.4 71.5 Residential 0.1

Grand Ave. - Between 3rd St. and Wilshire Blvd. 40 70.2 70.2 Church 0.0 - Between Wilshire Blvd. and 7th St. 40 71.3 71.4 Office 0.1 - South of 7th St. 40 70.7 71.0 Residential 0.3

a Detailed calculation worksheets, are included in Appendix IV.C.1. Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).

4. Alternate Traffic Impact

Roadway traffic noise impacts were also analyzed based on an Alternate Traffic Impact analysis The Alternate Traffic Impact analysis takes into account actual traffic counts conducted at the Project driveways that showed that the actual existing number of vehicle trips in and out of the project site was less than the ITE trip generation rate credit for the existing land uses on the project site discussed in the Transportation Study. Therefore, the Project-related traffic under this Alternate Traffic Impact analysis is greater than the traffic volume calculated above. Table IV.C-20 provides the calculated off-site traffic noise levels based on the Alternate Traffic Impact Analysis. As indicated in Table IV.C-20, Off-Site



Table IV.C-20 Off-Site Roadway Traffic Noise Impacts – “Alternate Traffic Impact Analysis”

Roadway Segment

Distance to Roadway

Centerline, feet


Adjacent Land Uses

Increase in Noise Levels

due to Project, CNEL


2020 With Project

Glendale Blvd. - Between Temple St. and Beverly Blvd. 35 73.9 73.9 Commercial 0.0

Francisco St. - Between 7th St. and Wilshire Blvd. 25 68.2 69.8 Commercial 1.6


School 0.0


Wilshire Blvd. - Between Alvarado St. and Lucas Ave. 40 72.5 72.6 School 0.1 - Between Lucas Ave. and Beaudry Ave. 40 72.4 72.5 Residential 0.1 - Between Francisco St. and Figueroa St. 40 72.3 72.9 Hotel/Office 0.6 - Between Figueroa St. and Grand Ave. 40 69.8 70.1 School 0.3

6th St. - Between Figueroa St. and Flower St. 35 69.9 69.9 Commercial 0.0 - Between Flower St. and Olive St. 35 69.2 69.2 Commercial 0.0 - East of Olive St. 35 70.7 70..7 Park 0.0

7th St. - Between Alvarado St. and Bixel St. 35 68.4 68.5 Residential/

School 0.1

- Between Bixel St. and Francisco St. 35 68.7 69.0 Residential 0.3 - Between Francisco St. and Figueroa St. 35 69.4 70.0 Hotel/Office 0.6



Table IV.C-20 Off-Site Roadway Traffic Noise Impacts – “Alternate Traffic Impact Analysis”

Roadway Segment

Distance to Roadway

Centerline, feet


Adjacent Land Uses


due to Project, CNEL


2020 With Project

- Between Figueroa St. and Grand Ave. 35 69.4 69.9 Hotel 0.5 - Between Grand Ave. and Alameda

Blvd. 35 69.0 69.2 Religious 0.2




a Detailed calculation worksheets are included in Appendix B of the noise study in Appendix IV.C.1. Source: Acoustical Engineering Services, 2010



Roadway Traffic Noise Impacts – “Alternate Traffic Impact Analysis,” the Project-related traffic would result in a maximum of 1.6 dBA CNEL increase in traffic noise along Francisco Street 7th Street and Wilshire Boulevard. At all other analyzed roadway segments, the increase due to project-related traffic would be lower (less than 1 dBA). The increase in traffic noise levels due to the Project would be below the 3 dBA CNEL significance threshold. Therefore, off-site traffic noise impacts associated with the Project would be less than significant, under the Project Alternate Traffic Impact scenario.

5. Composite Noise Level Impacts from Project Operations

An evaluation of composite noise levels, including all Project-related noise sources plus the existing ambient levels, was conducted to identify the potential maximum Project-related noise level increase that may occur at the noise-sensitive receptor locations. The overall sound environment at the areas surrounding the Project Site comprises contributions from each individual noise source associated with the typical daily operation of the Project. Principal on-site noise sources associated with the Project would include mechanical equipment, the parking facility, outdoor services, and the helistop. Table IV.C-21 (Composite Noise Impacts) presents the estimated noise from Project-related noise sources in terms of CNEL; noise calculation details are provided in Appendix IV.C.1. The composite noise impacts would be similar to the Project under the Alternate Traffic Impact scenario previously described. As indicated in Table IV.C-21, the Project would result in a maximum increase of 1.9 to 2.9 dBA CNEL at receptors adjacent to the Project Site (R0, R1, R2, and R3), none of which are noise-sensitive receptors. At all sensitive receptor locations, the Project’s composite noise impacts would be less than 1 dBA. The increases in noise levels due to the Project at all off-site receptors would be negligible in the existing noise environment. In addition, the increases would be below the significance threshold of a 3 dBA CNEL increase, which is an increase that is barely perceptible to the human ear. For all of these reasons, the composite noise level impacts due to the Project operation would be less than significant.

Table IV.C-21 Composite Noise Impacts

Location

Existing Ambient

Noise Levels, CNEL

Calculated Project-Related Noise Sources, CNEL Composite

Noise Levels,b

CNEL

Increase in Noise Levels due to Project Traffica Mechanical

Parking Facility

Outdoor Services Helistop

R0 71.7 64.3 70.0 53.7 61.1 44.1 74.6 2.9 R1 72.0 64.3 70.0 51.7 61.4 44.7 74.8 2.8 R2 76.1 53.4 70.0 51.7 70.8 44.7 78.0 1.9 R3 72.1 60.8 67.5 51.7 68.8 44.2 74.9 2.8 R4* 68.6 56.7 48.6 35.3 55.6 42.9 69.1 0.5 R5* 75.0 57.0 45.6 32.3 52.7 41.5 75.1 0.1 R6* 72.2 55.8 37.5 29.2 40.3 40.3 72.3 0.1 R7* 68.9 56.1 27.5 29.2 41.0 41.7 69.1 0.2 R8* 74.1 61.0 25.3 27.0 38.3 40.9 74.3 0.2 R9* 75.4 50.2 22.0 23.7 35.0 37.8 75.4 0.0 R10* 71.1 57.3 29.5 31.2 42.7 42.6 71.3 0.2



Table IV.C-21 Composite Noise Impacts

Location

Existing Ambient

Noise Levels, CNEL

Calculated Project-Related Noise Sources, CNEL Composite

Noise Levels,b

CNEL

Increase in Noise Levels due to Project Traffica Mechanical

Parking Facility

Outdoor Services Helistop

R11* 73.7 57.3 29.5 31.2 42.7 42.8 73.8 0.1 R12* 71.0 56.3 24.9 26.6 38.1 39.6 71.2 0.2 R13* 66.2 56.9 22.7 24.4 35.6 38.0 66.7 0.5 R14* 62.9 51.0 13.6 15.3 26.6 30.8 63.2 0.3 R15* 63.4 40.03 12.0 13.7 25.0 26.0 63.4 0.0 R16* 62.1 40.03 15.9 17.6 29.0 32.1 62.1 0.0 R17* 70.2 63.2 39.5 36.2 54.2 43.9 71.1 0.9 R18* 60.3 43.3 20.7 22.4 33.6 36.8 60.4 0.1 Notes: a Due to Project-related traffic only. b Composite noise levels including all Project-related noise sources plus existing ambient noise levels. c Estimated as no traffic analysis was made near these receptors, as they are located far away from the Project Site. * Receptor location falls under the City’s definition of a sensitive receptor. Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).

iii. Site Compatibility for New Buildings

As discussed previously, the noise environment that currently exists surrounding the Project Site would also affect the Project’s proposed on-site residential and hotel uses. Residential and hotel uses are proposed at the southwestern portion of the Project Site, primarily facing 7th Street. As indicated by the noise measurement data presented in Table IV.C-9, the Project Site is currently exposed to noise levels from 71.7 (ambient at R0) up to 76.1 dBA CNEL (ambient at R2), due primarily to traffic on adjacent roadways and the Harbor Freeway. Currently, the baseline ambient noise level at times exceeds the City-recommended noise standard used for multi-family residential and hotel developments (65 dBA CNEL) for the Project Site. In addition, the Project’s proposed on-site residential and hotel uses would be exposed to the Project’s stationary noise sources, particularly from the mechanical equipment, outdoor services and helistop. However, with inclusion of the project design feature that requires the building construction to provide adequate sound insulation in the design of the residential and hotel building, to meet the acceptable interior noise level of 45 dBA CNEL, impacts associated with the introduction of residential and hotel uses into the noise environment would be less than significant.

e. Land Use Equivalency Program

As described in Section II (Project Description), the Project would include the Land Use Equivalency Program to maintain flexibility of Project land uses and floor areas in order for the Project to respond to the changing needs of the Southern California economy. The Land Use Equivalency Program is designed



to direct how development will occur on the Project Site and allow for flexibility so that land uses can be exchanged for other permitted land uses such that no additional traffic generation would result from any exchange that is consistent with the Land Use Equivalency Program.

The exchange of office/commercial, retail, hotel, and/or residential land uses would be accomplished within the same building parameters, and the overall character of development would be the same as the Project uses analyzed. Regardless of the resultant mix of land uses under the Land Use Equivalency Program that would occur at the Project Site, the Project would generate construction noise and vibration levels consistent with those described previously, and through compliance with applicable building standards and the listed project design features and mitigation measures, impacts related to construction noise and vibration under the Land Use Equivalency Program would be less than significant.

Under the Land Use Equivalency Program, operational noise sources associated with building mechanical equipment, parking facilities, loading and trash/recycling areas outdoor services, and the helistop would occur within the same building parameters, and the overall character of development would be the same under the Project. Regardless of the resultant mix of land uses under the Land Use Equivalency Program that would occur at the Project Site, the Project would generate noise levels from these sources consistent with those described previously, and through compliance with applicable building standards and the listed mitigation measures, impacts related to these noise sources under the Land Use Equivalency Program would be less than significant. Under the Land Use Equivalency Program, the level of daily traffic generation could increase under some land use exchanges. This could potentially increase off-site roadway traffic noise impacts slightly. However, because the calculated traffic noise levels for the Project are well below the applicable 3 dBA threshold, increased noise levels from traffic would not have the potential to cause this threshold to be exceeded. Therefore, implementation of the Land Use Equivalency Program would have no additional significant impacts with respect to traffic noise.

f. Design Flexibility Program

The design of the Project as a conceptual plan allows for flexibility in the finalized building design within a determined set of parameters. Implementation of the Design Flexibility Program may result in changes to the location of the structures on the Project Site than those identified in the Conceptual Plan. Specifically, the location of the proposed helistop would not change in such a way as to create any new or increased impacts on sensitive receptors. Regardless of the placement of buildings on the Project Site, or uses within those buildings, under the Design Flexibility Program, the Project would generate noise levels consistent with those described previously, and through compliance with applicable building standards and the listed project design features and mitigation measures, impacts related to noise under the Design Flexibility Program would be less than significant.

3. CUMULATIVE IMPACTS

The Project together with the related projects, would contribute to cumulative noise impacts. The potential for cumulative noise impacts to occur is specific to the distance between each related project and



its stationary noise sources including the cumulative traffic that these projects would add to the surrounding roadway network.


As indicated in the Project’s transportation study, a total of 92 related projects are identified in the vicinity of the Project Site. While the majority of these related projects are located a substantial distance from the Project Site, there are four related projects within 1,000 feet of the Project Site, including Related Project No. 36, a Mixed-Use Development at 1027 Wilshire Boulevard (approximately 600 feet from the Project Site), Related Project No. 10, a Residential Development at 1067 6th Street (approximately 900 feet from the Project Site), Related Project No. 44, a Mixed-Use Development at 1111 Wilshire Boulevard (approximately 1,000 feet from the Project Site), and Related Project No. 92, a Mixed-use Development at 755 Figueroa Street (approximately 175 feet from the Project Site). Noise from construction activities would normally affect the areas immediately adjacent to the Project Site, meaning those that are less than 500 feet from the construction site, due to sound attenuation provided by the distance and the intervening buildings located between the construction sites and the noise sensitive receptors. Therefore, the noise from construction activities for two projects within 1,000 feet from each other could contribute to a cumulative noise impact for receptors located between the two construction sites.

Since the timing of the construction activities for these related projects cannot be defined, any quantitative analysis that assumes multiple, concurrent construction projects would be entirely speculative. Construction activities from at least four related projects would generate noise at each site and cumulative construction noise could exceed ambient noise levels at the nearest noise-sensitive uses. If construction of the nearest mixed-use developments were to occur concurrently with Project construction, the construction noise from these related projects could, in combination with the construction noise associated with the Project, contribute to a cumulative impact on the noise-sensitive receptors closest to these related project sites (the multi-family residential uses along Wilshire Boulevard and St. Paul Avenue, represented by R4).

In addition to the on-site construction activities, noise from off-site construction haul/deliver trucks could contribute to the cumulative noise impacts. As indicated in the Project transportation study (see Appendix IV.B), each project applicant would be required to prepare construction management plans and submit to LADOT for approval. The construction traffic management plans would be based on the nature and timing of the specific construction and other projects in the vicinity of the Project Site. Furthermore, each project applicant would be required to schedule construction-related deliveries, other than concrete and earthwork-related deliveries, to reduce travel during peak travel periods, which would minimize the noise impacts. Even so, if construction trucks from the related projects were to travel on the same routes and within the same hours as the Project, the Project’s contribution to cumulative off-site construction related truck traffic noise impacts could be considerable.

Construction-related noise levels from the related projects would be intermittent, temporary, and would comply with time restrictions and other relevant provisions in the LAMC. As required of the Project,



noise associated with cumulative construction activities would be reduced through proposed mitigation measures for each individual related project and through compliance with locally adopted and enforced noise ordinances. Similar to the Project, construction activities for each of the related projects would be required to comply with the City’s allowable construction hours as described previously and would be temporary. Even so, if construction of the nearest related projects were to occur concurrently with the Project’s construction, the Project’s contribution to cumulative construction related noise impacts could be considerable. Therefore, it is conservatively concluded that the Project’s construction noise effects could be cumulatively considerable, even after mitigation. However, the occurrence of this impact is speculative at this time, as it would depend on the timing of the related projects’ construction, which is currently unknown.

b. 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 100 feet). As indicated previously, the nearest related project is approximately 175 feet away from the Project. 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.

c. Operational Noise

Once developed, the Project and development in the surrounding area would generate noise that would contribute to cumulative noise from a number of community noise sources including vehicle travel, mechanical equipment (e.g., heating, ventilating, and air-conditioning systems), and lawn maintenance activities. Noise levels from stationary sources would be less than significant at the property line for each related project due to the City’s requirements that limit noise from on-site stationary-source noise such as outdoor air-conditioning equipment. Since the Project’s on-site stationary-sources’ (i.e., building mechanical equipment, parking facility, and outdoor services) impacts would result in less than significant impacts, stationary-sources noise impacts attributable to cumulative development of the related projects and the Project would also result in less than significant impacts.

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” conditions to the applicable significance criteria. Future cumulative conditions include traffic volumes from future ambient growth, and related development projects, with and without the Project. The calculated traffic noise levels under “existing” and “future cumulative” conditions are presented in Table IV.C-22 (Cumulative Off-Site Roadway Traffic Noise Impacts). It again should be noted that the calculated CNEL levels are conservative as these predicted noise levels are calculated in front of the roadways and do not account for the presence of any sound barriers or intervening structures. Cumulative traffic volumes would result in a maximum increase of 2.4 dBA CNEL along Francisco Street between 7th Street and Wilshire Boulevard, which is adjacent to the Project Site. At all other



analyzed roadway segments, the increase in cumulative traffic noise would be lower. The highest increase along a roadway segment with noise-sensitive uses would be 1.7 dBA CNEL. All of the cumulative noise level increases would be negligible in the existing noise environment. In addition, all of the increases would be less than the 3 dBA significance threshold, which is an increase that is barely perceptible to the human ear. For all of these reasons, the Project’s contribution to noise impacts due to off-site mobile noise sources (vehicular traffic) would not be cumulatively considerable.

Cumulative off-site traffic noise impacts were also analyzed based on the Project’s Alternate Traffic Impact analysis as summarized in Table IV.C-23. The cumulative traffic volumes based on the Project Alternate Traffic Impact analysis would result in a maximum increase of 3.6 dBA CNEL along Francisco Street between 7th Street and Wilshire Boulevard. The increase in noise level along Francisco Street would be below the 5 dBA CNEL significance threshold and thereby would remain within the “normally acceptable” category. The increase in cumulative traffic noise at all other analyzed roadway segments would be below the significance threshold of 3 dBA CNEL. As such, the Project’s contribution to noise impacts due to off-site mobile noise sources (vehicular traffic) would not be cumulatively considerable.

In addition to the on-site stationary noise sources and the off-site traffic noise sources, the Project’s helistop would contribute to the overall cumulative noise. However, as discussed previously, the Project’s helistop operation related noise would be a minimum of 23.5 dBA below the existing ambient noise levels (in terms of CNEL levels), which would not increase the ambient noise levels in the vicinity of the Project Site. For all of the reasons discussed, the Project’s contribution to noise impacts due to off-site mobile noise sources (vehicular traffic) and helistop operations would not be cumulatively considerable.

Table IV.C-22 Cumulative Off-Site Roadway Traffic Noise Impacts

Roadway Segment

Distance to Roadway

Centerline, feet


Adjacent Land Uses


due to Cumulative

Traffic, CNEL

Existing (2009)

Future Cumulative

(2020)b Glendale Blvd.

- Between Temple St. and Beverly Blvd. 35 73.2 73.9 Commercial 0.7


25

66.2

68.6

Commercial

2.4


School 1.0


Wilshire Blvd. - Between Alvarado St. and Lucas Ave. 40 71.6 72.5 School 0.9



Table IV.C-22 Cumulative Off-Site Roadway Traffic Noise Impacts

Roadway Segment

Distance to Roadway

Centerline, feet


Adjacent Land Uses


due to Cumulative

Traffic, CNEL

Existing (2009)

Future Cumulative

(2020)b - Between Lucas Ave. and Beaudry Ave. 40 71.3 72.4 Residential 1.1 - Between Francisco St. and Figueroa St. 40 70.8 72.5 Hotel/Office 1.7 - Between Figueroa St. and Grand Ave. 40 69.0 69.8 School 0.8

6th St. - Between Figueroa St. and Flower St. 35 69.3 69.9 Commercial 0.6 - Between Flower St. and Olive St. 35 68.7 69.2 Commercial 0.5 - East of Olive St. 35 70.0 70.7 Park 0.7


School 0.8

- Between Bixel St. and Francisco St. 35 67.8 68.9 Residential 1.1 - Between Francisco St. and Figueroa St. 35 68.2 69.5 Hotel/Office 1.3 - Between Figueroa St. and Grand Ave. 35 68.4 69.5 Hotel 1.1 - Between Grand Ave. and Alameda Blvd. 35 67.8 69.0 Religious 1.2




a Detailed calculation worksheets, are included in Appendix IV.C.1. b Includes traffic volumes from existing condition plus future growth, known related projects and Project-related. Source: Acoustical Engineering Services, 2010 (refer to Appendix IV.C.1).



Table IV.C-23 Cumulative Off-Site Roadway Traffic Noise Impacts – “Alternate Traffic Impact Analysis”

Roadway Segment

Distance to Roadway

Centerline, feet


Adjacent Land Uses

Noise Sensitive


due to Cumulative

Traffic, CNEL Existing (2009)

Future Cumulative

(2020)b Glendale Blvd.

- Between Temple St. and Beverly Blvd. 35 73.2 73.9 Commercial No 0.7

Francisco St. - Between 7th St. and Wilshire Blvd. 25 66.2 69.8 Commercial No 3.6


School Yes 1.0

- Between 6th St. and Wilshire Blvd. 25 68.8 70.0 Hospital Yes 1.2

Wilshire Blvd. - Between Alvarado St. and Lucas Ave. 40 71.6 72.6 School Yes 1.0 - Between Lucas Ave. and Beaudry Ave. 40 71.3 72.5 Residential Yes 1.2 - Between Francisco St. and Figueroa St. 40 70.8 72.9 Hotel/Office Yes 2.1 - Between Figueroa St. and Grand Ave. 40 69.0 70.1 School Yes 1.1

6th St. - Between Figueroa St. and Flower St. 35 69.3 69.9 Commercial No 0.6 - Between Flower St. and Olive St. 35 68.7 69.2 Commercial No 0.5 - East of Olive St. 35 70.0 70.7 Park Yes 0.7


School Yes 0.8

- Between Bixel St. and Francisco St. 35 67.8 69.0 Residential Yes 1.2 - Between Francisco St. and Figueroa St. 35 68.2 70.0 Hotel/Office Yes 1.8



Table IV.C-23 Cumulative Off-Site Roadway Traffic Noise Impacts – “Alternate Traffic Impact Analysis”

Roadway Segment

Distance to Roadway

Centerline, feet


Adjacent Land Uses

Noise Sensitive


due to Cumulative

Traffic, CNEL Existing (2009)

Future Cumulative

(2020)b - Between Figueroa St. and Grand Ave. 35 68.4 69.9 Hotel Yes 1.5 - Between Grand Ave. and Alameda Blvd. 35 67.8 69.2 Religious Yes 1.4

Figueroa St. - Between 3rd St. and 5th St. 40 73.3 74.2 Hotel Yes 0.9 - Between 5th St. and Wilshire Blvd. 40 73.6 74.9 Office No 1.3 - Between Wilshire Blvd. and 7th St. 40 72.2 73.1 Hotel/Office Yes 0.9 - Between 7th St. and Olympic Blvd. 40 71.3 72.3 Residential Yes 1.0 - Between Olympic Blvd. and Pico Blvd. 40 71.6 72.4 Residential Yes 0.8

Flower St. - Between 3rd St. and 5th St. 40 70.9 71.7 Hotel Yes 0.8 - Between 5th St. and Wilshire Blvd. 40 70.5 71.5 Office No 1.0 - Between Wilshire Blvd. and 8th St. 40 71.3 72.2 Office No 0.9 - South of 8th St. 40 70.8 71.6 Residential Yes 0.8

Grand Ave. - Between 3rd St. and Wilshire Blvd. 40 69.4 70.3 Church Yes 0.9 - Between Wilshire Blvd. and 7th St. 40 70.5 71.5 Office No 1.0 - South of 7th St. 40 69.9 71.2 Residential Yes 1.3

a Detailed calculation worksheets, are included in Appendix B of the noise study in Appendix IV.C.1. b Includes traffic volumes from existing condition plus future growth, known related projects and Project-related. Source: Acoustical Engineering Services, 2010



4. PROJECT DESIGN FEATURES AND MITIGATION MEASURES

As previously discussed, the following listed project design features would avoid or reduce Project-related noise effects:

PDF-1: Project construction shall not include the use of pile driving, to reduce construction noise and vibration impacts.

PDF-2: A temporary six-foot-tall noise barrier wall would be installed at the construction area along Francisco Street where construction trucks are lining up prior to entering the Project’s construction site. The barrier shall be placed on the top of the two-foot-tall K- rail that shall increase the effective height of the noise barrier to eight feet.

PDF-3: During operation, all mechanical equipment shall be enclosed and designed to meet the requirements of LAMC, Chapter XI, Section 112.02. The building mechanical/electrical equipment shall be designed not to exceed 63 dBA Leq (or 70 dBA CNEL) noise level at the Project Site property line. The building mechanical design shall be reviewed by a qualified acoustical consultant to ensure that the design shall meet the Project noise criteria.

PDF-4: The sound output of the proposed outdoor amplified sound systems for the outdoor pool and bar areas would be limited to a maximum sound level of 80 dBA Leq as calculated in Section 5.4.1.4. The design of the outdoor amplified sound systems would be reviewed by a qualified acoustical consultant to ensure that the design would meet the Project noise criteria.

PDF-5: The sound output of the proposed outdoor amplified sound systems for the outdoor plaza would be limited to a maximum sound level of 70 dBA (Leq) at 50 feet as calculated in Section 5.4.1.4. The design of the outdoor amplified sound systems would be reviewed by a qualified acoustical consultant to ensure that the design would meet the Project noise criteria.

PDF-6: The podium and rooftop parapets for areas that include an outdoor amplified sound system shall be of solid panel construction to provide sound attenuation.

PDF-7: If the proposed loading docks and trash/recycling areas would be located outside of the enclosed parking structure, all outdoor loading dock and trash/recycling areas shall be fully or partially enclosed such that the line-of-sight between these noise sources and any adjacent noise sensitive receptor shall be obstructed.

PDF-8: Building construction (i.e., exterior wall, window and door) shall provide adequate sound insulation to meet the acceptable interior noise level of 45 dBA CNEL, as required by Title 24 of the California Code of Regulations.

PDF-9: Unless required for safety precautions, the Project’s related helicopters shall use the recommended flight paths as shown in Figure IV.C-2.



Although Project-related construction is not anticipated to have significant noise impacts on the surrounding noise-sensitive land uses, the following Project mitigation measures are recommended to ensure the noise impacts would be less than significant:

a. Construction

MM-1: With the exception of required continuous concrete pours, construction activities shall be limited to Monday through Friday from 7:00 A.M. to 9:00 P.M., and from 8:00 A.M. to 6:00 P.M. on Saturdays. No construction activities shall occur on Sundays or national holidays.

MM-2: Power construction equipment shall be equipped with state-of-the-art noise shielding and muffling devices. All equipment shall be properly maintained to assure that no additional noise, due to worn or improperly maintained parts, would be generated.

MM-3: Stationary source construction equipment that may have a flexible specific location on-site (e.g., generators and compressors) shall be located so as to maintain the greatest distance from sensitive land uses and unnecessary idling of equipment shall be prohibited.

MM-4: To ensure that construction phase vibration impacts are less than significant, the Applicant or its successor shall comply with the specific requirements of the Metro construction design manual (MTA Design Criteria and Standard, Volume III, Adjacent Construction Design Manual, Section 2.3 – 2.4, R92-DE303-3.00, Revision 9: 02.02.99), when excavation is within 25 feet of the Metro subway tunnel.

MM-5: The Applicant shall implement the following requirements during construction activities in connection with the on-site building demolitions:

a. Construction materials/debris in excess of 2,000 pounds shall be lowered via a crane.

b. Construction materials/debris drop shall be performed in accordance with Table IV.C-15, with the consideration given to the estimated drop weight and height, as required to maintain a maximum of 0.5 inch per second (PPV) at off-site receptors R0, R1, and R3 and a maximum of 0.25 inch per second (PPV) at off-site receptor R2.

b. Operation

As discussed previously, with implementation of the project design features, operation of the Project would result in a less than significant impact to the off-site and the future on-site noise-sensitive uses. Therefore, no mitigation measures are required for the Project’s long-term operations.

c. Cumulative Construction

As discussed previously, construction noise impacts from construction of the Project with concurrent construction of the related projects is conservatively concluded to be significant. Mitigation measures are



described to reduce the Project’s construction noise levels. Similar mitigation measures would likely be imposed upon each related project. No additional mitigation measures for the related projects can be known at this time.

5. LEVEL OF SIGNIFICANCE AFTER MITIGATION


While construction noise impacts are less than significant, compliance with the recommended mitigation measures would ensure a reduction of construction noise. Mitigation measure 1 would preclude construction noise impacts from occurring during the noise-sensitive nighttime periods, or at any time on Sundays and national holidays, in compliance with the City of Los Angeles Noise Regulation. Noise level reductions attributable to mitigation measures 2 and 3, although not easily quantifiable, would ensure the noise impacts associated with construction activities would be reduced to the extent practicable.

As previously discussed, if the identified related projects were to occur concurrently with the Project’s construction, cumulative construction noise impacts could be significant, albeit speculative. However, noise impacts would be reduced through proposed mitigation measures for each individual related project and compliance with locally adopted and enforces noise ordinances. Therefore, the noise impacts associated with construction activities for each of the related projects likely would be reduced to a less than significant level. However, it is conservatively concluded that the Project’s construction noise effects could be cumulatively considerable, even after mitigation.

b. Operational Noise

Implementation of the project design features would ensure that the Project would not result in any significant noise impacts to on-site or off-site noise sensitive receptors during long-term Project operations. As such, operational noise impacts would be less than significant.

As discussed previously, the cumulative noise impacts from stationary sources at the Project and other related projects would not result in a significant noise impact, based on the assumption that each of the related projects would implement project specific mitigation measures or noise control as required to meet the City’s requirements. In addition, as discussed previously, the Project’s traffic noise impacts and helistop operation noise impacts would also not be cumulatively considerable. As such, cumulative noise impacts would be less than significant with implementation of the mitigation measures.

c. Groundborne Vibration

Implementation of mitigation measure 4 would ensure that construction activities (i.e., site excavation associated with the garage) would be carried out in accordance with Metro requirements for construction work located near the Metro facilities (i.e., Metro subway tunnel), and the impact would be less than significant. Additionally, mitigation measure 5 would ensure that vibration impacts during construction would be reduced to a less than significant level.

iv. environmental impact analysis c. noiseplanning.lacity.org/eir/wilshiregrandredevproj/deir/deir...

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