3h noise 081108 - la city planning · 3h. noise occidental college specific plan 3h-2 esa / d205278...

3. Environmental Setting, Impacts and Mitigation Measures

Occidental College Specific Plan 3H-1 ESA / D205278 Draft EIR September 2008

3H. Noise This section presents information on existing noise conditions in the vicinity of the project site, identifies potential impacts associated with noise and vibration due to the construction and operation of the proposed project, as well as potential significant impacts and mitigation.

Noise Definition Sound is mechanical energy transmitted by pressure waves in a compressible medium such as air. Noise can be defined as unwanted sound. Sound is characterized by various parameters that include the rate of oscillation of sound waves (frequency), the speed of propagation, and the pressure level or energy content (amplitude). In particular, the sound pressure level has become the most common descriptor used to characterize the loudness of an ambient sound level. The decibel (dB) scale is used to quantify sound intensity. Since the human ear is not equally sensitive to all frequencies within the entire spectrum, noise measurements are weighted more heavily within those frequencies of maximum human sensitivity in a process called “A-weighting,” referred to as dBA. In general, a difference of more than 3 dBA is a perceptible change in environmental noise, while a 5 dBA difference typically causes a change in community reaction. An increase of 10 dBA is perceived by people as a doubling of loudness (USEPA, 1974).

Because sound pressure can vary over one trillion times within the range of human hearing, a logarithmic loudness scale is used to keep sound intensity numbers at a convenient and manageable level. Therefore, the cumulative noise level from two or more sources will combine logarithmically, rather than linearly (i.e., simple addition). For example, if two identical noise sources produce a noise level of 50 dBA each, the combined noise level would be 53 dBA, not 100 dBA.

Several methods have been devised to relate noise exposure over time to human response. A commonly used noise metric for this type of study is the Community Noise Equivalent Level (CNEL). The CNEL, originally developed for use in the California Airport Noise Regulation, adds a 5-dBA penalty to noise occurring during evening hours from 7 PM to 10 PM, and a 10-dBA penalty to sounds occurring between the hours of 10 PM to 7 AM to account for the increased sensitivity to noise events that occur during the quiet late evening and nighttime periods. Thus, the CNEL noise metric provides a 24-hour average of A-weighted noise levels at a particular location, with an evening and a nighttime adjustment, which reflects increased sensitivity to noise during these times of the day. The Day Night Level (DNL) and the CNEL are similar noise descriptors in most urban traffic-dominated environments. These descriptors are best used for measuring average increases in overall noise over a daily period and not single event noises, which are best described as unique events.

Figure 3H.1 displays typical sound levels measured in the environment and the subjective human response to the various intensities of noise.

3. Environmental Setting, Impacts and Mitigation Measures 3H. Noise


Vibration Definition Vibration is an oscillatory motion through a solid medium in which the motion’s amplitude can be described in terms of displacement, velocity, or acceleration. There are several different methods that are used to quantify vibration. The peak particle velocity (PPV) is defined as the maximum instantaneous peak of the vibration signal. The PPV is most frequently used to describe vibration impacts to buildings. The root mean square (RMS) amplitude is most frequently used to describe the affect of vibration on the human body. The RMS amplitude is defined as the average of the squared amplitude of the signal. Decibel notation (vdb) is commonly used to measure RMS. The decibel notation acts to compress the range of numbers required to describe vibration.1

Typically, groundborne vibration generated by man-made activities attenuates rapidly with distance from the source of the vibration. Man-made vibration issues are therefore usually confined to short distances (i.e., 500 feet or less) from the source. Sensitive receptors for vibration are the same as sensitive receptors for noise: residences, schools, motels, hotels, libraries, religious institutions, hospitals and similar uses..

3H.1 Environmental Setting

Existing Noise Sources The proposed project area is located in a residential setting. Existing residences are located directly adjacent to the proposed project primarily on the north (northwestern), west, and south. Existing outdoor activity areas on campus include: a multi-purpose athletic facility located on the west side of the proposed project area; a baseball field located along the southeast of the project area; and a soccer field to the south side of the project area.

The noise environment in and around the proposed project area is typical of a college or university setting, and activity at the athletic fields and vehicular traffic in and around the proposed project area is considered to be consistent with this setting.

Noise monitoring was conducted to ascertain the existing ambient daytime and night time noise levels in the project area.2 A summary of noise measurement data is provided in Table 3H-1. To quantify the existing noise environment in the project area, sound level measurements were taken at five residential locations around the perimeter of the proposed project area.

The average existing noise levels based on the measurement data in Table 3H-1 is 52.5 CNEL, well below the City’s allowed ambient noise level of 70 CNEL.

1 Federal Transit Administration, Transit Noise and Vibration Impact Assessment, April 1995. 2 Noise levels were measured using a calibrated Metrosonic dB-308A Sound Analyzer.

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TABLE 3H-1 SUMMARY OF AMBIENT NOISE MEASUREMENT DATA

Location Date Duration Noise Level Noise Sources

Campus Road behind B. Bell Field August 3, 2001 10 minutes 59 CNEL Traffic, Recreational activities

Campus Road behind Physical, Earth, And Environmental Sciences Center

August 3, 2001 10 minutes 59 CNEL Traffic, Recreational activities

Near Anderson Field August 3, 2001 10 minutes

50 CNEL at 3:55 PM and 11:03 PM

Traffic, Recreational activities

Near Soccer Field August 3, 2001 10 minutes



Near Eaton Street August 3, 2001 10 minutes



Existing Vibration Sources Similar to ambient noise levels, any vibration environment in the project area is dominated by traffic from nearby roadways. However, existing vibration levels at the proposed project area are typically not perceptible.

Sensitive Receptors Noise-sensitive land uses are locations where people reside or where the presence of unwanted sound could adversely affect the use of the land. Residences, schools, hospitals, guest lodging, libraries, churches, nursing homes, auditoriums, concert halls, amphitheaters, playgrounds and parks are considered noise-sensitive.

Figure 3H.2 shows the location of sensitive receptors near the project site. The nearest sensitive receptors to the project site are single-family residences located along the northern and northwestern, southern, western, and eastern regions of the project area boundary, as well as the Yosemite Recreation Center located about 1,200 feet from the northeast project boundary. Figure 3H.2 identifies all sensitive receptors located within a one-half mile from the center of the project site. These are in addition to the residential neighborhoods bordering the project site and the students at the College attending classes or using the campus library during construction activities. Some residents, particularly those near Building Opportunity Sites (BOS) 1, 5, 8, 20, 24, 28, all located along the perimeter of the site, are either adjacent to potential construction or across narrow rights-of-way (see Figure 2.3 for a map of the BOS). Residences are approximately 50 feet to 100 feet from proposed Building Opportunity Sites.

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3H.2 Regulatory Background

Federal

Federal Noise Policies The U.S. Department of Housing and Urban Development (HUD) has set a goal of 45 dBA Ldn as a desirable maximum interior noise standard for HUD-assisted residential units.3

Federal Vibration Policies The Federal Railway Administration (FRA) and the Federal Transit Administration (FTA) have published guidance relative to vibration impacts. According to FRA, fragile buildings (including historic monuments) can be exposed to groundborne vibration levels of 0.5 PPV without experiencing structural damage.4 The FTA has identified the human annoyance response to vibration levels as 80 VdB.5

State

State Noise Policies The Department of Health Services (DHS) has adopted guidelines based, in part, on the community noise compatibility guidelines established by DHS for use in assessing the compatibility of various land use types with a range of noise levels.6 An exterior noise level up to 65 dBA CNEL is “normally acceptable” for residential uses, without special noise insulation requirements. A noise level of 65 to 70 dBA CNEL or more is identified as "conditionally acceptable" for residential uses. A “conditionally acceptable” designation indicates that conventional construction, with closed windows and fresh air supply systems (e.g., air conditioning) normally suffice for noise insulation. A noise level of 70 to 75 dBA CNEL is identified as "normally unacceptable" for multi-family residential uses and requires an analysis to demonstrate potential noise mitigation measures.

Title 24, Part 2 of the California Code of Regulations contains requirements for the construction of new hotels, motels, apartment houses, and dwellings other than detached single-family dwellings intended to limit the extent of noise transmitted into habitable spaces. These requirements are collectively known as the California Noise Insulation Standards. For limiting noise transmitted from exterior sources, the Standards set forth an interior standard of 45 Ldn in any habitable room with all doors and windows closed, and require an acoustical analysis demonstrating how dwelling units have been designed to meet this interior standard (where such units are proposed in areas subject to transportation noise levels greater than 60 Ldn).

3 The Ldn and the CNEL are similar noise descriptors and rarely differ by more than 1 dBA. 4 Federal Railway Administration, High-Speed Ground Transportation Noise and Vibration Impact Assessment,

December 1998. 5 Federal Transit Administration, Transit Noise and Vibration Impact Assessment, April 1995. 6 California Department of Health Services, Office of Noise Control, February 1976.



State Vibration Policies There are no adopted state policies or standards for groundborne vibration. Caltrans does recommend that extreme care be taken when sustained pile driving occurs within 7.5 meters (25 feet) of any building, and 15 to 30 meters (50 to 100 feet) of a historic building or a building in poor condition.

Local City of Los Angeles General Plan Noise Element. The City of Los Angeles General Plan Noise Element outlines guidelines for noise and land use compatibility for development and planning purposes (City of Los Angeles, 1999). The Noise Element has adopted local guidelines based, in part, on the community noise compatibility guidelines established by DHS for use in assessing the compatibility of various land use types with a range of noise levels. These guidelines are presented in Table 3H-2.

TABLE 3H-2 CITY OF LOS ANGELES GUIDELINES FOR NOISE COMPATIBLE LAND USE

Day-Night Average Exterior Sound Level (CNEL dB)

Land Use Category 50 55 60 65 70 75 80

Residential Single Family, Duplex, Mobile Home A C C C N U U

Residential Multi-Family A A C C N U U

Transient Lodging, Motel, Hotel A A C C N U U

School, Library, Church, Hospital, Nursing Home A A C C N N U

Auditorium, Concert Hall, Amphitheater C C C C/N U U U

Sports Arena, Outdoor Spectator Sports C C C C C/U U U

Playground, Neighborhood Park A A A A/N N N/U U

Golf Course, Riding Stable, Water Recreation, Cemetery A A A A N A/N U

Office Building, Business, Commercial, Professional A A A A/C C C/N N

Agriculture, Industrial, Manufacturing, Utilities A A A A A/C C/N N

A = Normally acceptable. Specified land use is satisfactory, based upon assumption buildings involved are conventional construction, without any special noise insulation.

C = Conditionally acceptable. New construction or development only after a detailed analysis of noise mitigation is made and needed noise insulation features are included in project design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning normally will suffice.

N = Normally unacceptable. New construction or development generally should be discouraged. A detailed analysis of noise insulation features included in the design of a project.

U = Clearly unacceptable. New construction or development generally should not be undertaken.

City of Los Angeles Noise Ordinance. The Los Angeles Municipal Code (LAMC) codifies the City’s noise policies. LAMC indicates that no construction or repair work shall be performed between the hours of 9 PM and 7 AM the following day, Monday through Friday, since such activities would generate loud noises and disturb persons occupying sleeping quarters in any



adjacent dwelling, hotel, apartment or other place of residence.7 No person, other than an individual homeowner engaged in the repair or construction of his/her single-family dwelling, shall perform any construction or repair work of any kind or perform such work within 500 feet of land so occupied before 8 AM or after 6 PM on any Saturday or on a federal holiday or at any time on any Sunday. Under certain conditions, the City may grant a waiver to allow limited construction activities to occur outside of the limits described above.

According to the Noise Ordinance:

[N]o person shall operate or cause to be operated any machinery, equipment, tools, or other mechanical or electrical device, or engage in any other activity in such a manner as to create any noise which would cause the noise level on the premises of any other occupied property, or, if a condominium, apartment house, duplex, or attached business, within any adjoining unit, to exceed the ambient noise level by more than five decibels.8

The LAMC also specifies the maximum noise level of powered equipment or powered hand tools.9 Any powered equipment or hand tool that produces a maximum noise level exceeding 75 dBA at a distance of 50 feet is prohibited. However, this noise limitation does not apply where compliance is technically infeasible. Technically infeasible means that the above noise limitation cannot be met despite the use of mufflers, shields, sound barriers and/or any other noise reduction device or techniques during the operation of equipment.

3H.3 Impacts and Mitigation Measures

Methodology Construction and operational point source noise impacts were evaluated by comparing anticipated noise levels to the guidelines set forth in the LAMC. Roadway noise impacts were projected using the FHWA-RD-77-10810 prediction model. This methodology allows the user to define roadway configurations, barrier information (if any), and receiver locations. Roadway-noise attributable to project development was calculated and compared to baseline noise levels that would occur under the “no project” condition to determine significance.

Groundborne vibration impacts were evaluated by identifying potential vibration sources, measuring the distance between vibration sources and surrounding structure locations, and making a significance determination.

Criteria for Determining Significance The criteria used to determine the significance of an impact are based on the Initial Study Checklist in Appendix G of the CEQA Guidelines, the LA CEQA Thresholds Guide11 and City 7 LAMC, Chapter IV, Article 1, Section 41.40, January 29, 1984; and Chapter XI, Article 2, Section 112.04,

August 8, 1996. 8 Ibid. 9 LAMC, Chapter XI, Article 2, Section 112.05. August 8, 1996. 10 FHWA is the abbreviation for the Federal Highway Administration. 11 LA CEQA Thresholds Guide, Your Resource for Preparing CEQA Analyses in Los Angeles, 2006



precedent. Please refer to the Initial Study (Appendix A) for further clarification. Based on the CEQA Guidelines, and the LA CEQA Thresholds Guide the proposed project would be deemed to have a significant effect on the environment with respect to noise and/or groundborne vibration if it would result in:

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

• Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels;

• A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project; and/or

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

• Construction activities lasting more than one day would exceed existing ambient exterior noise 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.

• A project would normally have a significant impact on noise levels from project operations if the project causes the ambient noise level measured at the property line of affected uses to increase by 3 dBA in CNEL to or within the "normally unacceptable" or "clearly unacceptable" category, or any 5 dBA or greater noise increase (see the chart below).

A change in noise levels of less than 3 dBA is not discernible to the general population; an increase in average noise levels of 3 dBA is considered barely perceptible, while an increase of 5 dBA is considered readily perceptible to most people.

Project Impacts

Construction Noise Noise impacts from construction activities occurring within the project site would be a function of the noise generated by construction equipment, the equipment location, and the timing and duration of the noise-generating activities. Construction activities would include five stages: (1) demolition; (2) site preparation; (3) foundation; (4) structural; and (5) finishing and cleanup. Each stage involves the use of different kinds of construction equipment and, therefore, has its own distinct noise characteristics. The anticipated noise level associated with each construction phase appears in Table 3H-3. In addition, typical noise levels generated by individual pieces of equipment are displayed in Table 3H-4.

The construction noise levels presented in Table 3H-3 represent conservative conditions in which the maximum amount of construction equipment would be operating during a one-hour period.



These estimated noise levels would not be continuous, nor would they be typical of noise levels throughout the construction period. As indicated in Table 3H-3, due to the type of construction equipment, the highest level of construction noise would be expected to occur during the site clearing and finishing and cleanup phases. Composite equipment use during these phases would generate a noise level of 89 dBA (without mufflers) at a distance of 50 feet from construction activity. Sensitive receptors within the project area would be about 50 feet from the closest anticipated construction. These sensitive receptors would include students attending classes at the College during construction.

TABLE 3H-3 ESTIMATED NOISE LEVELS FROM CONSTRUCTION ACTIVITIES

Construction Phase Noise Level (dBA, Leqa)

Ground Clearing 84 Excavation 89 Foundations 78 Construction 85 Finishing 89

a Average noise levels correspond to a distance of 50 feet from the noisiest piece of equipment associated with a given phase of

construction and 200 feet from the rest of the equipment associated with that phase.

SOURCE: Bolt, Baranek, and Newman, Noise from Construction Equipment and Operations, Building Equipment, and Home Appliances, 1971.

TABLE 3H-4 NOISE LEVELS FROM CONSTRUCTION EQUIPMENT

Construction Equipment Noise Level (dBA, Leq at 50 feet)

Dump Truck 88 Portable Air Compressor 81 Concrete Mixer (Truck) 85 Jack Hammer 88 Dozer 87 Paver 89 Generator 76 Pneumatic Tools 85 Concrete Pump 82 Backhoe 85

SOURCE: Cunniff, Environmental Noise Pollution, 1977; U.S. Department of Transportation Federal Transit Administration, Transit Noise and Vibration Impact Assessment, 1995.

Earth-moving equipment used during the grading phase of construction is typically the noisiest of the construction equipment, generating noise levels up to approximately 89 dBA at 50 feet from the source. The noise levels shown in Table 3H-4 represent noise levels for equipment under full load rather than chronic (hourly or longer) noise levels. Average construction noise would be approximately 80 dBA at 50 feet during construction work hours. Earth-moving equipment is anticipated to be used for approximately two to four months during the grading and site preparation phase of each individual project.



Table 3H-5 shows how sound would be attenuated with distance.

Construction noise represents a short-term impact on ambient noise levels. Noise generated by construction equipment, including trucks, graders, bulldozers, concrete mixers and portable generators can reach high levels. The greatest construction noise levels are typically generated by heavy grading equipment.

TABLE 3H-5 ATTENUATION OF CONSTRUCTION NOISE LEVELS AWAY FROM SOURCES

Distance (feet) Noise Levels (dBA, Leq)

50 76-89 100 70-83 200 64-77 400 58-71 800 52-65

SOURCE: U.S. Department of Transportation Federal Transit Administration, Transit Noise and Vibration Impact Assessment, 1995.

The peak noise level for most of the equipment that would be used during project construction is 70 to 95 dBA at a distance of 50 feet. These noise levels are based upon worse case conditions.

The equipment used for demolition and site grading would generate the highest construction noise levels. The peak noise level generated by the equipment that would be used during grading could range from 70 dBA to 95 dBA at a distance of 50 feet. At 150 feet, peak construction noise levels could range from 61 to 86 dBA. At 1,000 feet, peak noise levels would range from 44 to 69 dBA. Note again that these noise levels are based upon worse-case conditions. Typically, noise levels near a construction site would be less. Typically, noise levels are reduced by 26 dBA inside structures.

In some areas within the project area, construction and grading may occur directly adjacent to residences. In other areas, construction and grading would occur well away from sensitive receptors. When construction occurs directly adjacent to homes and/or schools, high noise levels can occur (100 dBA), but for very short periods of time as a piece of equipment operates directly adjacent to a sensitive receptor. As the equipment moves away from a single receptor, the noise level at that receptor would drop. Average noise levels depend on the construction site’s proximity to sensitive receptors and the level of activity. Higher levels of activity with more equipment operating concurrently would generate higher noise levels than if only a few pieces of equipment are operated intermittently.

To put these noise levels in perspective, the typical sound level that permits relaxed conversation with 100 percent intelligibility is 45 dBA. This drops to 60 percent intelligibility at 70 dBA. In addition, 50 percent of people report that noise levels of 75 dBA disturb sleep.



The City of Los Angeles has specific limitations on construction noise levels. The LAMC specifies the maximum noise level of powered equipment or powered hand tools.12 Any powered equipment or hand tool that produces a maximum noise level exceeding 75 dBA at a distance of 50 feet from a sensitive receptor is prohibited. However, this noise limitation does not apply where compliance is technically infeasible. Technically infeasible means that the above noise limitation cannot be met despite the use of mufflers, shields, sound barriers and/or any other noise reduction device or techniques during the operation of equipment.

Construction activity would occur within the time confines set forth within the Noise Ordinance and construction activity would not result in the exposure of sensitive receptors to noise levels in excess of standards established in the Noise Ordinance.

Unmitigated maximum construction noise levels are potentially significant. Noise attenuation can be achieved by installing noise barriers along the perimeter of project sites that are located adjacent to sensitive receptors. Installation of an eight-foot noise wall could achieve up to a 10 dBA decrease in construction noise at the closest sensitive receptor. Implementation of Mitigation Measures 3H.1 through 3H.7 would result in less than significant impacts related to construction noise.

Operational Noise The City of Los Angeles identifies two separate types of permanent noise sources: (1) mobile (vehicles) and (2) stationary (outside recreational activities, parking lot noise, car alarm noise, vehicle horns, etc). To control transportation related noise sources such as arterial roads, freeways, airports and railroads, the City has established guidelines for acceptable community noise levels in the Noise Element of the General Plan (see Table 3H-1).

The proposed project operation phase would not result in substantial increases in traffic levels in the project area. A doubling of traffic is typically needed to cause an audible increase in roadway noise levels. However, the proposed project would not double the traffic on any roadway.

Noise associated with the operation of the proposed project would include service delivery/supply vehicles, activities at loading areas, outside recreational activities, parking lot noise, car alarm noise, vehicle horns and mechanical equipment (air conditioners, trash compactors, emergency generators, etc.). Although several noise sources would be introduced by the proposed project, many of them would operate for only brief time periods, such as delivery truck movements and trash compactors, which are located in the loading dock area. These types of sources usually do not operate concurrently and occurs intermittently. Other noise sources, such as air conditioning equipment, operate for comparatively longer periods of time but do not cause significant and disturbing noise.

Noise is also associated with athletic events, which for softball, baseball and soccer, are attended by small crowds (approximately 50 people). The National Collegiate Athletic Association (NCAA) has rules that require its soccer referees to use whistles and time to be signaled by air 12 LAMC. Chapter XI, Article 2, Section 112.05. August 8, 1996.



horns so that there is no confusion. This noise is periodic throughout an athletic event, and applies to existing athletic facilities. Activities on existing athletic fields would not change substantially as a result of the Specific Plan, except at BOS 7 and Anderson Field where night games would be possible as a result of the new permanent lighting. It is not anticipated that noise associated with recreational activities and sports would change substantially from existing conditions, except at BOS 5, where any proposed sports field activities would be new to that area of the campus and would be heard by residents across Avenue 50. These noises would be during day-time hours at BOS 5 (since night lighting would be prohibited —see Mitigation Measure 3A.5), and would be similar to noise heard in other residences near sports facilities on Campus Road. Less than significant impacts are anticipated to result from proposed new activities on BOS 5 and extended hours of play on BOS 5 and 7.

Groundborne Vibration Both construction and operation of development projects can generate groundborne vibration. In general, demolition of structures during construction generates the highest vibrations. Vibratory compactors or rollers, pile drivers, and pavement breakers can generate perceptible vibration. Heavy trucks can also generate groundborne vibration, which varies depending on vehicle type, weight, and pavement conditions. The FTA has published standard vibration velocities for construction equipment operations. The Peak Particle Velocity (PPV) for various pieces of construction equipment are listed in Table 3H-6.

TABLE 3H-6 VIBRATION VELOCITIES FOR CONSTRUCTION EQUIPMENT

Equipment Approximate Peak Particle Velocity at

50 feet, inch/second

Approximate Peak Particle Velocity at

125 feet, inch/second

Large bulldozer 0.031 0.008 Caisson drilling 0.031 0.008 Loaded trucks 0.027 0.007 Jackhammer 0.012 0.003 Small bulldozer 0.001 0.0003

a Data reflects typical vibration level.

SOURCE: USDOT Federal Transit Administration, 1995; Terry A. Hayes Associates, 2006.

The use of heavy equipment (e.g., a large bulldozer) generates vibration levels of 0.089 PPV at a distance of 50 feet. The nearest residences to the project area are located along the northern (and northwestern), southern, western and eastern project area boundary, some of which are as little as approximately 65 feet from the edge of the project site. These residences could experience vibration levels of approximately 0.031 PPV. Groundborne vibration attenuates quickly with distance and the PPV level from heavy equipment would be approximately 0.008 at 125 feet. The majority of construction activity would be more than 125 feet from residential structures and would not be considered a disturbance that would require mitigation.



The project would not introduce any significant sources of groundborne vibration during operation that would potentially impact adjacent land uses. Groundborne vibration resulting from operation of the proposed project would primarily be generated by trucks making periodic deliveries to the proposed project site. However, these types of deliveries would be consistent with regular industrial deliveries that are currently made along adjacent roadways and would not increase groundborne vibration above existing levels. Thus, groundborne vibration impacts resulting from long-term project operations are anticipated to be less than significant.

Mitigation Measures All of the following mitigation measures shall be applied to the proposed project to reduce project related noise.

Measure 3H.1: The proposed project shall comply with City of Los Angeles Noise Ordinance such that construction activities shall be performed in accordance with the applicable City of Los Angeles noise standards. The construction contract shall specify that noise intensive construction or repair work shall be prohibited between the hours of 9 PM and 7 AM on any weekday, before 8 AM or after 6 PM on Saturday or on a national holiday, or at any time on Sundays.

Measure 3H.2: The proposed project shall require all construction equipment, stationary and mobile, to be equipped with properly operating and maintained muffling devices.

Measure 3H.3: During construction activities, construction managers and inspectors shall serve as the contact persons in the event that noise levels become disruptive to local residents. A sign will be posted at the construction site with contact phone number, at all times.

Measure 3H.4: The proposed project shall provide advanced notification to adjacent residences where construction will take place by posting notices adjacent to the project area with regard to the schedule of construction activities. The notice shall include contact numbers of the construction managers and inspectors.

Measure 3H.5: The proposed project shall require stationary construction equipment and vehicle staging areas to be placed such that noise is directed away from sensitive receptors.

Measure 3H.6: The proposed project shall erect a temporary sound barrier such that the line-of-sight between sensitive receptors located within 100 feet of construction activities and construction activity is blocked. This wall shall extend along the southeastern and southwestern borders of the project area.

Measure 3H.7: Heavy equipment shall be located as far away from sensitive receptors as possible.



3H.4 Cumulative Impacts Construction Construction noise represents a short-term impact on ambient noise levels. Noise generated by construction equipment, including trucks, graders, bulldozers, concrete mixers and portable generators can reach high levels. Grading activities typically represent one of the highest potential sources for noise impacts. The most effective method of controlling construction noise levels is through local control of construction hours and by limiting the hours of construction based on City ordinances. While overlapping construction projects are anticipated within the proposed project, as well as cumulative projects, compliance with City ordinances and implementation of Mitigation Measures 3H.1 through 3H.7 would reduce this potential impact to a level of less than significant.

Operational Cumulative projects may result in increased traffic on local roadways. However, future conditions with the project compared to existing conditions would not result in substantial increases in noise levels as a doubling of traffic is typically needed to cause an audible increase in roadway noise levels. However, the proposed project would not double the traffic on any roadway.

3H.5 Significance after Mitigation Less than significant.

3h noise 081108 - la city planning · 3h. noise occidental college specific plan 3h-2 esa / d205278...

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