IV. ENVIRONMENTAL IMPACT ANALYSIS I. NOISE

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1 IV. ENVIRONMENTAL IMPACT ANALYSIS I. NOISE 1. INTRODUCTION This section analyzes potential noise and vibration impacts associated with construction and operation of the proposed project. The analysis describes the existing noise environment within the vicinity of the project site, estimates future noise levels at surrounding land uses resulting from construction and operation of the proposed project, identifies the potential for significant impacts, and provides mitigation measures to address significant impacts. In addition, an evaluation of the potential cumulative noise impacts from the proposed project and known related projects is also provided. Noise calculation worksheets are included in Appendix G of this Draft EIR. 2. ENVIRONMENTAL SETTING a. Noise and Vibration Basics (1) Noise Noise is most often defined as unwanted sound. Although sound can be easily measured, the perceptibility of sound is subjective and the physical response to sound complicates the analysis of its impact on people. People judge the relative magnitude of sound sensation in subjective terms such as noisiness or loudness. Sound pressure magnitude is measured and quantified using a logarithmic ratio of pressures, the scale of which gives the level of sound in decibels (db). The human hearing system is not equally sensitive to sound at all frequencies. Therefore, to approximate this human, frequency dependent response, the A weighted filter system is used to adjust measured sound levels. The A weighted sound level is expressed in dba. This scale de emphasizes low frequencies to which human hearing is less sensitive and focuses on mid to high range frequencies. Although the A weighted scale accounts for the range of people s response, and therefore, is commonly used to quantify individual event or general community sound levels, the degree of annoyance or other response effects also depends on several other perceptibility factors. These factors include: Ambient (background) sound level; Magnitude of sound event with respect to the background noise level; Duration of the sound event; Number of event occurrences and their repetitiveness; and Time of day that the event occurs. IV.I 1

2 IV.I. Noise September 2011 People judge the relative magnitude of sound sensation by subjective terms such as loudness or noisiness. That is, a change in sound level of 3 db is considered just perceptible, a change in sound level of 5 db is considered clearly noticeable, and a change in 10 db is recognized as twice as loud. 1 In an outdoor environment, sound levels attenuate through the air as a function of distance. Such attenuation is called distance loss or geometric spreading and is based on the source configuration, point source, or line source. For a point source, the rate of sound attenuation is 6 db per doubling of distance from the noise source. For example, a sound level of 50 dba at a distance of 25 feet from the noise source would attenuate to 44 dba at a distance of 50 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 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 not fully blocked), some barrier insertion loss would still occur, however to a lesser extent. Additionally, a receptor located on the same side of the wall as a noise source may actually experience an increase in the perceived noise level as the wall reflects noise back to the receptor, thereby compounding the noise. Noise barriers can provide noise level reductions ranging from approximately 5 dba (where the barrier just breaks the line of sight between the source and receiver) to an upper range of 20 dba with a more substantial barrier. 3 Community noise levels usually change continuously during the day. The equivalent sound level (L eq ) is normally used to describe community noise. The L eq is the equivalent steady state A weighted sound level that would contain the same acoustical energy as the time varying A weighted sound level during the same time interval. For intermittent noise sources, the maximum noise level (L max ) is normally used to represent the maximum noise level measured during the measurement. Maximum and minimum noise levels, as compared to the L eq, are a function of the characteristics of the noise source. As an example, sources such as generators have maximum and minimum noise levels that are similar to L eq since noise levels for steadystate noise sources do not substantially fluctuate. However, as another example, vehicular noise levels along local roadways result in substantially different minimum and maximum noise levels when compared to the L eq since noise levels fluctuate during pass by events. The Noise Ordinance uses the L eq to evaluate noise violations. To assess noise levels over a given 24 hour time period, the community noise equivalent level (CNEL) descriptor is used in land use planning. CNEL is the time average of all A weighted sound levels for a 24 hour period with a 5 dba adjustment (upward) added to the sound levels which occur in the evening (7:00 P.M. to 10:00 P.M.) and a 10 dba adjustment (upward) added to the sound levels which occur in the night (10:00 P.M. to 7:00 A.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 a community noise Engineering Noise Control, Bies & Hansen, Caltrans, Technical Noise Supplement (TeNS), Ibid. IV.I 2

3 September 2011 IV.I. Noise element of a General Plan and is also used by for land use planning in the City s Noise Element of the General Plan. 4 (2) Ground Borne Vibration 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. With respect to ground borne vibration, velocity and acceleration descriptors are typically used, as most vibration sensors are velocity or acceleration sensor. In addition, the response of humans, buildings, and equipment to vibration is more accurately described using velocity or acceleration. 5 Vibration amplitudes are usually described as either peak, as in peak particle velocity (PPV) or root mean square (RMS). The RMS vibration velocity level can be presented in inches/second or in VdB (referenced to 1 micro inches per second). The peak level represents the maximum instantaneous peak of the vibration signal and the RMS represents the average of the squared amplitude of the vibration signal. In addition, vibrations can be measured in the vertical, horizontal longitudinal, or horizontal transverse directions. Ground vibrations are most often greatest in the vertical direction. 6 Therefore, the analysis of ground borne vibration is addressed in the vertical direction. b. Existing Conditions (1) Noise Sensitive Receptor Locations Some land uses are considered more sensitive to intrusive noise than others due to the amount of noise exposure and the types of activities typically involved at the receptor location. The City of L.A. CEQA Thresholds Guide (2006) states that residences, schools, motels and hotels, libraries, religious institutions, hospitals, nursing homes, and parks are generally more sensitive to noise than commercial and industrial land uses. Noise sensitive receptors were selected based on the relative distance from the receptors to the project site, in accordance with the City of L.A. CEQA Thresholds Guide screening criteria. Existing noise sensitive uses in the project vicinity are shown in Figure IV.I 1, Noise Sensitive Uses and Noise and Vibration Measurement Locations, and include the following: Multi Family Residential Areas: Located to the east side of the project site along Moreno Drive and Durant Drive. The nearest multi family residential properties are located approximately 60 feet from the project site. These residential uses are located within the City of Beverly Hills. School Uses: Beverly Hills High School (BHHS) and in particular the Science and Technology Center building is located south of the project site on Moreno Drive approximately 25 feet from the nearest property line of the project site, but approximately 170 feet from the project s residential building and approximately 60 feet from the ancillary building. (2) Ambient Noise Levels The predominant noise source surrounding the project site is roadway noise from the Santa Monica Boulevard to the north and Moreno Drive to the east. Secondary noise sources including commercial/retail State of California, General Plan Guidelines, Federal Transit Authority, Transit Noise and Vibration Impact Assessment, Final Report, page 7 3, April California Department of Transportation (Caltrans), Transportation Related Earthborne Vibrations, page 4, February IV.I 3

4 IV.I. Noise September 2011 related activities along Santa Monica Boulevard, such as loading dock/delivery truck activities, trash compaction, parking garage, and refuse services activities. Measured Noise Levels Existing Conditions Ambient noise measurements were taken at four locations to asses existing noise levels at the project site and nearby land uses in the vicinity of the project site. 7 The four noise measurement locations are identified as R1, R2, R3, and R4 as shown in Figure IV.I 1. As shown in Table IV.I 1, Summary of Ambient Noise Measurements, short term (15 minute) measurements were conducted at locations R1 and R4 on Thursday, May 12, 2011 between the hours of 11:00 A.M. and 1:00 P.M. Long term (24 hour) measurements were conducted at locations R2 and R3 from Friday, May 13, 2011 through Sunday, May 15, The four noise measurement locations are further described below: Table IV.I 1 Summary of Ambient Noise Measurements Measurement Location, Day, and Time R1 North project boundary Thursday, 5/12/11(11 A.M. to 1 P.M.) R2 East project boundary/multi family residential uses Friday, 5/13/11 (full 24 hours) Saturday, 5/14/11 (full 24 hours) Sunday, 5/15/11 (full 24 hours) R3 South project boundary/school uses Friday, 5/13/11 (full 24 hours) Saturday, 5/14/11 (full 24 hours) Sunday, 5/15/11 (full 24 hours) R4 Multi family residential uses along Durant Drive Thursday, 5/12/11 (11 A.M. to 1 P.M.) Distance to Nearest Proposed Building Project Site Measured Ambient Noise Levels a (dba) Daytime (7 A.M. to 10 P.M.) Hourly L eq 60 feet feet 300 feet Nighttime (10 P.M. to 7 A.M.) Hourly L eq 24 Hour Average CNEL 66.8 N/A b N/A b a Detailed measured noise data, including hourly L eq levels, are included in Appendix G. b The CNEL measurements are based on 24 hour measurements. Therefore, CNEL values are not estimated for locations R1 and R4, which were measured from 11:00 A.M. to 1:00 P.M. Source: PCR Services Corporation, The ambient noise measurements were conducted using the 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 applicable manufacturer specification. IV.I 4

5 LEGEND Project Site Noise Sensitive Receptor Locations Noise Measurement Locations Merv Griffin Way Vibration Measurement Locations Santa Monica Monica Blvd Blvd S Santa Santa a Monica Monica Blvd Blvd V3 Durant Dr R1 R2 V2 R4 Robbins Dr R3 V1 S Moreno Dr Century Park E PCR N Feet Noise Sensitive Uses and Noise and Vibration Measurement Locations FIGURE IV.I-1 Source: PCR Services Corporation, 2008; Google Earth, 2008.

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7 September 2011 IV.I. Noise Noise Measurement Location R1: This measurement location represents the project site. The sound measuring device (sound level meter) was placed within the project boundaries near Santa Monica Boulevard. Noise Measurement Location R2: This measurement location represents the existing sound environment at the project site and the nearby multi family residential units east of the project site. The sound level meter was placed on the east boundary of the project site near Moreno Drive. Noise Measurement Location R3: This measurement location represents the project site and BHHS located immediately south of the project site. The sound level meter was placed on the south boundary of the project site. Noise Measurement Location R4: This measurement location represents the multi family residential uses along Durant Drive. The sound level meter was placed on Durant Drive approximately 200 feet from the northeast corner of Durant Drive and Moreno Drive. As also shown in Table IV.I 1, the measured CNEL at the project site ranged from 56.5 CNEL at the southern project boundary to 69.2 CNEL at the eastern project boundary. The uses state land use noise compatibility guidelines for evaluating whether the CNEL level in a particular neighborhood is acceptable for a particular use. 8 The noise compatibility guidelines are shown in Table IV.I 2, City of Los Angeles Land Use Compatibility for Community Noise. CNEL guidelines for specific land uses are classified into four categories: (1) normally acceptable, (2) conditionally acceptable, (3) normally unacceptable, and (4) clearly unacceptable. As indicated, the noise environment in the project area (i.e CNEL to 69.2 CNEL) is considered normally acceptable to conditionally acceptable for multi family residential uses. Modeled Noise Conditions Traffic Noise To further characterize the area s noise environment, the CNEL noise levels generated by existing traffic on local roadways was calculated using a noise prediction model based on calculation methodologies provided in the California Department of Transportation (Caltrans) Technical Noise Supplement (TeNS) document and traffic data included in the Traffic Study for the proposed project. 9 A model calibration test (i.e. actual sampled data) was performed at Santa Monica Boulevard, west of Moreno Drive (R1), for comparison to the noise level predicted by the noise prediction mode. A minimum of 15 minute noise recording was made concurrent with logging of actual traffic volumes and auto fleet mix (i.e., standard automobile, medium duty truck, or heavy duty truck). The traffic counts were entered into the noise model along with the observed speed, lane configuration, and distance to the roadway to calculate the traffic noise levels. The results of the traffic noise model calibration are provided in Table IV.I 3, Traffic Noise Model Calibration Results. As indicated, the noise model results are within less than 1 dba of the measured noise levels, which is within the industry standard tolerance of the noise prediction model. Therefore, the project specific traffic noise prediction model is considered accurate and specific to project conditions. 8 9 CEQA Thresholds Guide, 2006, page I.2 4. The roadway noise calculation procedures provided in the Caltrans TeNS are consistent with Federal Highway Administration RD roadway noise prediction methodologies. This methodology allows for the definition of roadway configurations, barrier information (if any), and receiver locations. IV.I 7

8 IV.I. Noise September 2011 Land Use Table IV.I 2 Land Use Compatibility for Community Noise Normally Acceptable a Community Noise Exposure CNEL, dba Conditionally Acceptable b Normally Unacceptable c Clearly Unacceptable d Single Family, Duplex, Mobile 50 to to to 75 Above 70 e Homes Multi Family Homes 50 to to to 75 Above 70 e Schools, Libraries, Churches, 50 to to to 80 Above 80 Hospitals, Nursing Homes Transient Lodging Motels, Hotels 50 to to to 80 Above 80 Auditoriums, Concert Halls, 50 to 70 Above 65 Amphitheaters Sports Arena, Outdoor Spectator 50 to 75 Above 70 Sports Playgrounds, Neighborhood Parks 50 to to 75 Above 72 Golf Courses, Riding Stables, Water Recreation, Cemeteries Office Buildings, Business and Professional Commercial Industrial, Manufacturing, Utilities, Agriculture 50 to to 80 Above to to 77 Above to to 80 Above 75 a b c d e Normally Acceptable: Specified land use is satisfactory, based upon the assumption that any buildings involved are of normal conventional construction without any special noise insulation requirements. Conditionally Acceptable: New construction or development should be undertaken only after a detailed analysis of the noise reduction requirements is made and needed noise insulation features included in the design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning will normally suffice. Normally Unacceptable: New construction or development should generally be discouraged. If new construction or development does proceed, a detailed analysis of the noise reduction requirements must be made and needed noise insulation features included in the design. Clearly Unacceptable: New construction or development should generally not be undertaken. This 70 db figure is quoted directly from the City of L.A. CEQA Thresholds Guide. However, other sources quote this number as 75 db (i.e., State of California General Plan Guidelines, Preliminary Draft, Governor s Office of Planning and Research, October 2002, p. 258, and Noise Element of the General Plan, Department of City Planning Los Angeles, California, February 1999, p. I 1). This may be a typographical error in the City of L.A. CEQA Thresholds Guide (2006). Note that this potential error does not affect the determination of significant impacts for this report. Source: City of L.A. CEQA Thresholds Guide, The traffic noise prediction model calculates the 24 hour CNEL noise levels based on specific information including, average daily traffic volume (ADT), percentages of day, evening and nighttime traffic volumes relative to ADT, vehicle speed, and distance between the noise receptor and the roadway. Vehicle mix/distribution information used in the noise calculation is shown in Table IV.I 4, Vehicle Mix for Traffic Noise Model. As indicated in Table IV.I 5, Predicted Existing Vehicular Traffic Noise Levels, the calculated CNEL for the analyzed roadway segments as a result of existing traffic volumes ranged from 58.1 dba CNEL to 72.7 dba CNEL at a distance of 25 feet based on surface street traffic volumes only. As shown therein, IV.I 8

9 September 2011 IV.I. Noise Table IV.I 3 Traffic Noise Model Calibration Results Road Segment/Noise Measurement Location Santa Monica Blvd./ R1 (P.M.) Autos Traffic Counts During Noise Readings 15 minutes (A.M./P.M.) Medium Trucks a Heavy Trucks b Measured Traffic Noise Levels L eq (dba) Project Traffic Noise Model Predicted Noise Levels L eq (dba) Difference between Predicted and Measured Levels dba a b Medium Truck 2 axle trucks based on field observations. Heavy Truck 3 or more axles trucks and buses based on field observations. Source: PCR Services Corporation, Table IV.I 4 Vehicle Mix for Traffic Noise Model Vehicle Type Daytime hours (7 A.M. to 7 P.M.) Evening Hours (7 P.M. to 10 P.M.) Percent of ADT Nighttime Hours (10 P.M. to 7 A.M.) Total Automobile Medium Truck a Heavy Truck b a b Medium Truck 2 axle trucks based on field observations. Heavy Truck 3 or more axles trucks and buses based on field observations. Source: PCR Services Corporation, traffic related noise levels at the nearest sensitive receptors to each analyzed roadway segment exceed normally acceptable noise levels at the majority of the studied residential areas (i.e., 65 dba CNEL or lower), except at residential uses along Roxbury Drive, Bedford Drive, Prosser Avenue, Spalding Drive, Moreno Drive, Durant Drive, Veteran Drive, Olympic Boulevard between Century East and Spalding Drive, Olympic Boulevard east of Spalding Drive, and Century Park West between Santa Monica Boulevard and Constellation Avenue. (3) Vibration Sensitive Receptor Locations The analysis of vibration below is based on the vibration effects that could occur at the nearest sensitive receptors to the project site. These include the nearest residential unit located across Moreno Drive from the project site, and the Beverly Hills High School Science and Technology Center (Science and Technology Center) located across a driveway abutting the southern edge of the project site. The analysis also addresses IV.I 9

10 IV.I. Noise September 2011 Roadway Segment Table IV.I 5 Predicted Existing Vehicular Traffic Noise Levels Adjacent Land Use Existing CNEL (dba) at Referenced Distances from Roadway Right of Way Adjacent 25 Feet 50 Feet Santa Monica Boulevard West of Century Park West Residential Between Century Park West & Century Park East Residential Between Century Park East & Moreno Dr. Residential Between Moreno Dr. & Wilshire Blvd. Residential Between Wilshire Blvd. & Beverly Dr. Residential East of Beverly Dr. Residential South Santa Monica Boulevard Between Century Park East & Moreno Dr. Residential Wilshire Boulevard Northwest of Santa Monica Blvd. Residential Olympic Boulevard Between Overland Ave. & Prosser Ave. Residential Between Prosser Ave. & Beverly Glen Blvd. Residential Between Beverly Glen Blvd. & Century Park West Residential Between Century Park West and Century Park East Residential Between Century Park East & Spalding Dr. Residential East of Spalding Dr. Residential Roxbury Drive North of Santa Monica Blvd. Residential North of Olympic Blvd. Residential South of Olympic Blvd. Residential Roxbury Drive/Brighton Way South of Wilshire Blvd. Residential Bedford Drive North of Santa Monica Blvd. Residential Prosser Avenue North of Olympic Blvd. Residential South of Olympic Blvd. Residential Beverly Glen Boulevard North of Santa Monica Blvd. Residential Between Santa Monica Blvd. & Olympic Blvd. Residential South of Olympic Blvd. Residential Veteran Drive North of Santa Monica Blvd. Residential South of Santa Monica Blvd. Residential Overland Avenue Between Santa Monica Blvd. & Olympic Blvd. Residential South of Olympic Blvd. Residential IV.I 10

11 September 2011 IV.I. Noise Roadway Segment Adjacent Land Use Existing CNEL (dba) at Referenced Distances from Roadway Right of Way Adjacent 25 Feet 50 Feet Century Park West Between Santa Monica Blvd. & Constellation Ave. Residential Between Constellation Ave. & Olympic Blvd. Residential Century Park East Between Olympic Blvd. & Pico Blvd. Residential Spalding Drive North of Olympic Blvd. Residential South of Olympic Blvd. Residential North of Moreno Dr. Residential Avenue of the Stars Between Santa Monica Blvd. & Constellation Ave. Residential Between Constellation Ave. & Olympic Blvd. Residential Moreno Drive Between Santa Monica Blvd. & Durant Dr. Residential South of Durant Dr. Residential Durant Drive East of Moreno Dr. Residential Pico Boulevard West of Beverly Glen Blvd. Residential Between Beverly Glen Blvd. and Motor Ave. Residential Source: PCR Services Corporation, potential vibration impacts at a residential location on Durant Drive, within the residential neighborhood further east to indicate the extent of more distant vibration effects. (4) Ground Borne Vibration Environment The existing ground vibration environment surrounding the project site is comprised primarily of auto traffic on nearby streets. A vibration survey was conducted at the project s southern boundary near the Science and Technology Center (Vibration Measurement Location V1) and at two residential receptors including multi family residential uses across Moreno Drive (Vibration Measurement Location V2) and multi family residential uses along Durant Drive (Vibration Measurement Location V3) as shown in Figure IV.I 1, above. In general, the current ground vibration environment in the vicinity of the project site is below the barely perceptible level of 0.01 inch per second PPV. However, vibration sampling at the project site identified a couple of short events (less than a few seconds) in which the measured ground vibration reached a peak level of inch per second PPV at location V2 and inch per second PPV at location V1 IV.I 11

12 IV.I. Noise September 2011 which is within the distinctly perceptible level. Measured ground vibration levels of inch per second PPV were also identified at location V1. 10 c. Regulatory Framework Many government agencies have established noise standards and guidelines to protect citizens from potential hearing damage and various other adverse physiological and social effects associated with noise. The project site is located within the Century City Community of the. Therefore, applicable policies and regulations from the are used to assess potential noise impacts from the proposed project. (1) General Plan Noise Element 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. Noise Element policies that relate to the proposed project include the following: 11 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) Los Angeles Municipal Code The Noise Regulation is provided in Chapter XI of the LAMC. Section of the LAMC provides procedures and criteria for the measurement of the sound level of offending noise sources. In accordance with the LAMC, a noise level increase of 5 dba over the existing average ambient noise level at an adjacent property line is considered a noise violation. To account for people s increased tolerance for shortduration noise events, the Noise Regulation provides a 5 dba allowance for noise source occurring more than five but less than fifteen minutes in any one hour period and an additional 5 dba allowance (total of 10 dba) for noise source occurring five minute or less in any one hour period. 12 The LAMC indicates that in cases where the actual measured ambient conditions are not known or are less than 50 dba, the presumed daytime (7:00 A.M. to 10:00 P.M.) and nighttime (10:00 P.M. to 7:00 A.M.) minimum ambient noise levels defined in Section of the LAMC should be used. The presumed ambient noise Detailed information regarding the vibration testing is included in Appendix G of this Draft EIR. Ground vibration recordings were performed in 2008 and are considered representative of the current site conditions; as ground conditions have not changed since 2008, and comparisons of noise sampling between 2008 and 2011 indicated that changes in traffic generated noise (and cooccurring vibration) are negligible. Any slight increase in traffic would render the use of the 2008 data a more conservative estimate as project additions to the vibration setting would represent a greater percentage increase. The monitoring included Long term (24 hour) vibration measurements at the project s southern boundary (V1) and short term (15 minute) vibration measurements at the two off site locations (V2 and V3). The portable seismic monitoring system Model SSU 3000LC manufactured by Geo Sonics was programmed to record ground movement in one minute intervals in the form of PPV, in units of inch per second. Noise Element of the Los Angeles City General Plan, adopted February 3, Los Angeles Municipal Code, Chapter XI, Article I, Section (b). IV.I 12

13 September 2011 IV.I. Noise levels for these areas as set forth in the LAMC Sections and are provided in Table IV.I 6, City of Los Angeles Presumed Ambient Noise Levels. For residential zoned areas, the presumed ambient noise level is 50 dba during the daytime and 40 dba during the nighttime. Zone Table IV.I 6 Presumed Ambient Noise Levels Daytime Hours (7 A.M. to 10 P.M.) dba (L eq ) Nighttime Hours (10 P.M. to 7 A.M.) dba (Leq) Residential Commercial Manufacturing Heavy Manufacturing Source: Los Angeles Municipal Code, Section Section of the LAMC sets a maximum noise level for construction equipment of 75 dba at a distance of 50 feet when operated within 500 feet of a residential zone. Compliance with this standard is only required where technically feasible. 13 Section of the LAMC prohibits construction between the hours of 9:00 P.M. and 7:00 A.M. Monday through Friday, 6:00 P.M. and 8:00 A.M. on Saturday, and at any time on Sunday. In general, the Department of Building and Safety enforces noise ordinance provisions relative to equipment and the Los Angeles Police Department enforces provisions relative to noise generated by people. (3) Guidelines for Noise Compatible Land Use The 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 City of L.A. CEQA Thresholds Guide (2006) in terms of CNEL. CNEL guidelines for specific land uses are classified into four categories: (1) normally acceptable, (2) conditionally acceptable, (3) normally unacceptable, and (4) clearly unacceptable. As shown in Table IV.I 2, on page 7 a CNEL value of 65 dba is the upper limit of what is considered a normally acceptable noise environment for multi family residential uses, although a CNEL as high as 70 dba is considered conditionally acceptable. The upper limit of what is considered normally unacceptable for residential uses is set at 75 dba CNEL. 14 New development should generally be discouraged within the unacceptable category. However, if new development does proceed, a detailed analysis of the noise reduction requirements must be made and needed noise insulation features included in the design In accordance with the Noise Ordinances, technically feasible means that the established noise limitations can be complied with at a project site, with the use of mufflers, shields, sound barriers, and/or other noise reduction devices or techniques employed during the operation of equipment. City of L.A. CEQA Thresholds Guide, Section I.2, IV.I 13

14 IV.I. Noise September 2011 (4) Ground Borne Vibration (State and Federal Standards) The does not have specific policies or guidelines relative to ground borne vibration. As such, policies and guidelines from Caltrans and Federal Transit Administration (FTA) are utilized to assess impacts due to ground borne vibration. Ground borne vibration impacts are evaluated based on a) potential building damage, b) potential human annoyance, and c) potential effect on vibration sensitive equipment. The FTA and Caltrans have adopted guidelines/recommendations to limit ground borne vibration based on the age and/or condition of the structures that are located in close proximity to construction activity. Studies by the Caltrans and FTA show vibration velocity levels greater than 0.04 inch per second PPV are distinctly perceptible to human and become strongly perceptible when reaching 0.10 inch per second PPV as shown in Table IV.I 7, Guideline Vibration Annoyance Potential Threshold Criteria. Table IV.I 7 Guideline Vibration Annoyance Potential Threshold Criteria Human Response Maximum PPV (inch per second)/vdb Transient Sources a Continuous/Frequent Intermittent Sources b Barely perceptible 0.04/ /68 Distinctly perceptible 0.25/ /80 Strongly perceptible 0.90/ /88 Severe 2.00/ /100 a b Transient sources created a single isolated vibration event, such as blasting or drop balls. Continuous/frequent intermittent sources include impact pile drivers, pogo stick compactors, crack anseat equipment, vibratory pile drivers, and vibratory compaction equipment. Source: Caltrans, Transportation and Construction Induced Vibration Guidance Manual, Table 20, The building damage threshold with respect to ground vibration varies depending on the age and condition of the structure in question. While modern industrial/commercial buildings can endure 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 historical nature 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.I 8, Guideline Vibration Damage Potential Threshold Criteria. FTA recommends maximum vibration levels associated with the nature of activities affected. These guidelines recommend a maximum of 75 VdB for frequent vibration events at institutional uses such as schools (78 VdB for occasional events and 83 VdB for infrequent events); and 72 VdB for frequent events at residences and buildings where people normally sleep (75 VdB for occasional events and 80 VdB for infrequent events); and 65 VdB for buildings where vibrations would interfere with interior operations, e.g. a building that might have sensitive equipment such as an optical microscope Federal Transit Administration, Transit Noise and Vibration Impact Assessment, Table 8 1, May IV.I 14

15 September 2011 IV.I. Noise Table IV.I 8 Guideline Vibration Damage Potential Threshold Criteria Structure and Condition Maximum PPV (inch per second) Transient Sources a Continuous/Frequent Intermittent Sources b Extremely fragile buildings, ruins, ancient monuments Fragile buildings Historic and some old buildings Older residential structures New residential structures Modern industrial/commercial buildings a b Transient sources created a single isolated vibration event, such as blasting or drop balls. Continuous/frequent intermittent sources include impact pile drivers, pogo stick compactors, crack an seat equipment, vibratory pile drivers, and vibratory compaction equipment. Source: Caltrans, Transportation and Construction Induced Vibration Guidance Manual, Table 19, PROJECT IMPACTS a. Methodology (1) On Site Construction Noise Noise impacts from on site construction, truck staging, and hauling are evaluated by determining the noise levels generated by the different types of construction activity, calculating the construction related noise level at nearby sensitive receptor locations, and comparing these construction related noise levels to existing ambient noise levels (i.e., noise levels without construction noise). More specifically, the following steps were undertaken to calculate construction period noise impacts: 1. Ambient noise levels at surrounding sensitive receptor locations were estimated based on field measurement data (see Table IV.I 1 on page 5); 2. Typical noise levels for each construction equipment were obtained from the Federal Highway Administration (FHWA) roadway construction noise model (RCNM); 3. Distances between construction site locations (noise source) and surrounding sensitive receptors were measured using project architectural drawings, Google Earth, and site plans; 4. The construction noise level was then calculated, in terms of hourly L eq, for sensitive receptor locations based on the standard point source noise distance attenuation factor of 6.0 dba for each doubling of distance; and 5. Construction noise levels were then compared to the construction noise significance thresholds identified below. IV.I 15

16 IV.I. Noise September 2011 (2) Off Site Roadway Noise (Construction and Operation) Roadway noise impacts have been evaluated using the Caltrans TeNS methodology based on the roadway traffic volume data provided in the Traffic Impact Study prepared for the proposed project. This methodology allows for the definition of 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 without project condition. (3) Stationary Point Source Noise (Operation) Stationary point source noise impacts have been evaluated by identifying the noise levels generated by outdoor stationary noise sources such as rooftop mechanical equipment and loading dock activities, calculating the hourly L eq noise level from each noise source at surrounding sensitive receiver property line locations, and comparing such noise levels to existing ambient noise levels. More specifically, the following steps were undertaken to calculate outdoor stationary point source noise impacts: 1. Ambient noise levels at surrounding sensitive receptor locations were estimated based on field measurement data (see Table IV.I 1 on page 5); 2. Distances between stationary noise sources and surrounding sensitive receptor locations were measured using project architectural drawings, Google Earth, and site plans; 3. Stationary source noise levels were then calculated for each sensitive receptor location based on the standard point source noise distance attenuation factor of 6.0 dba for each doubling of distance; 4. Noise level increases were compared to the stationary source noise significance thresholds identified below; and 5. For outdoor mechanical equipment, the maximum allowable noise emissions from any and all outdoor mechanical equipment were specified such that noise levels would not exceed the significance threshold of 5 dba identified below. (4) Ground Borne Vibration (Construction and Operation) Ground borne vibration impacts were evaluated by identifying potential vibration sources, measuring the distance between vibration sources and surrounding structure locations, and making a significance determination based on the significance thresholds described below. b. Significance Thresholds Appendix G of the CEQA Guidelines provides a set of screening questions that address impacts with regard to Noise Impacts. These questions are as follows: Would the project result in: Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies; IV.I 16

17 September 2011 IV.I. Noise Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels; A substantial permanent increase in ambient noise levels in the vicinity of the project above levels existing without the project; A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project. (1) Construction The following thresholds of significance are set forth in the City of L.A. CEQA Thresholds Guide (2006), which states that a project would normally have a significant impact on noise levels from construction if: 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 any time on Sunday. Since the project construction period would have a duration of more than 10 days and would not occur 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 any time on Sunday (consistent with provisions of the LAMC), noise during construction would have a significant impact if: (2) Operation Noise 1 Project construction activities cause the exterior ambient noise level to increase by 5 dba or more at a noise sensitive use, as measured at the property line of any sensitive use The City of L.A. CEQA Thresholds Guide (2006) provides guidelines for defining significant noise impacts due to operations. The Los Angeles guideline states that a significant impact related to operational noise would result if: Noise 2 The proposed project would cause ambient noise levels to increase by 5 dba CNEL or more and the resulting noise falls on a land use within an area categorized as either normally acceptable or conditionally acceptable (see Table IV.I 2 for description of these categories); or Noise 3 The proposed project would cause ambient noise levels to increase by 3 dba CNEL or more and the resulting noise falls on a land use within an area categorized as either normally unacceptable or clearly unacceptable. IV.I 17

18 IV.I. Noise September 2011 Noise 4 Project related operational (i.e., non roadway) noise sources such as outdoor building mechanical/electrical equipment increase ambient noise level by 5 dba, thus causing a violation of the City Noise Ordinance. In addition, the Noise Ordinance provides guidance for calculation of short term annoying sounds of the type that could be generated within the project s parking structure. Accordingly the following threshold would apply: Noise 5 The maximum noise (Lmax) generated from the operation of the parking structure (i.e., car alarm) exceeds the average (Leq) ambient noise level by 10 dba. (3) Ground Borne Vibration The does not have a significance threshold to assess vibration impacts during construction. Thus, the FTA and Caltrans standards described above are used to evaluate potential impacts related to project construction. All structures that are located within the immediate vicinity of the project site are considered well engineered (as opposed to fragile or extremely fragile ). Therefore, impacts relative to ground borne vibration would be considered significant if the following future event were to occur: Noise 6 Potential Building Damage Project construction activities cause ground borne vibration levels to exceed 0.5 inch per second PPV at the nearest off site building. Noise 7 Potential Human Annoyance Project construction and operation activities cause groundborne vibration levels to exceed 75 VdB at the Science and Technology Center; or 72 VdB at nearby residential development. Noise 8 Potential Impact on Vibration Sensitive Equipment Use Project construction activities cause ground borne vibration levels to exceed 65 VdB (0.002 inch per second RMS) at the Science and Technology Center. c. Project Design Features As noted in Section II., Project Description, project design features would be implemented by the Applicant as Conditions of Approval during design, construction and operation of the proposed project. The following project design features would be implemented as Conditions of Approval to reduce the level of noise generated by the project during construction and operations. These project design features were therefore taken into account in the analysis of potential project impacts. (1) Construction The project contractor(s) shall equip all construction equipment, fixed or mobile, with properly operating and maintained noise mufflers, consistent with manufacturers standards. All construction equipment shall be stored on site. All heavy truck traffic shall enter and exit the project site near its northwest corner, thus avoiding the use of local streets south of Santa Monica Boulevard. IV.I 18

19 September 2011 IV.I. Noise An approximately 20 foot temporary noise barrier/wall capable of reducing noise by at least 15 dba shall be erected along the southern edge of the project site adjacent to the Science and Technology Center, and a 12 foot sound wall shall be located along Moreno Drive. Anticipated extraordinary noise activities shall be coordinated with the BHHS school representatives. The Applicant shall coordinate with BHHS to limit noise generating construction activities during school activities that require a very quiet environment, like testing. The project shall limit construction hours to 7:00 A.M. to 9:00 P.M. on weekdays only, with no construction on weekends. Hauling shall be limited to the hours of 8:30 A.M. to 4:30 P.M. and would be scheduled to alleviate congestion at peak school times. (2) Design Features to Reduce Operation Impacts Outdoor mounted mechanical and electrical equipment in the vicinity of sensitive receptors shall be designed with appropriate noise control devices, such as sound attenuators, or acoustics louvers. All rooftop mechanical equipment shall be enclosed or screened from view with parapet screening. Loading docks and trash/recycling areas shall be enclosed within the project buildings. d. Analysis of Project Impacts Impacts of the project due to noise from project activities would, for the most part, be similar for development with the Conventional Parking Option and with the Automated Parking Option. For construction, both parking options would require similar excavation and grading for site preparation, similar foundation work, and substantially similar building erection programs. The maximum noise level on a given day, the basis of the analysis below, would be the same for both programs. Construction noise levels for the Automated Parking Option would be slightly reduced due to its smaller ancillary building, and reduced building erection. Further, noise impacts associated with the parking structure during project operations, e.g. horns, screeching wheels, etc., would not occur, as automobiles would be shut off and left at the entryway to be moved by electronic conveyance systems. Otherwise, noise due to project operations would be the same under both options, since both options would have similar site uses and generate the same amount of traffic. As such, the following analysis addresses the impacts of both the Conventional Parking Option and the Automated Parking Option. (1) Construction Noise (a) On Site Noise impacts from construction activities are generally a function of the noise generated by construction equipment, the equipment location, the sensitivity of nearby land uses, and the timing and duration of the noise generating activities. Construction activities at the project site would include four stages: (1) mass grading; (2) fine grading and foundation work; (3) building construction; and (4) paving. Each stage involves the use of different kinds of construction equipment, and therefore has its own distinct noise characteristics. Grading typically involves the use of such equipment as a rubber tired loader, backhoe, excavator, rubber tire dozer, drill rig, and other equipment. Fine grading and foundation work involves the use of such equipment as a rubber tired dozer, loader, tractor, backhoe, concrete pump truck, and water truck. Building construction typically involves the use of such equipment as cranes, forklifts, a skid steer loader, backhoes, generators, welders, concrete/industrial saws, concrete pumps and aerial lifts. Paving requires the use of cement and mortar mixers, pavers and paving equipment, and rollers. The proposed IV.I 19

20 IV.I. Noise September 2011 project would be constructed using typical construction techniques. No blasting or impact pile driving would be used. Construction of the proposed project is estimated to last approximately three years. The existing project site does not require any demolition activities, however one mass site grading phase is expected for debris removal, as well as preparation of the ground for the one level of partially subterranean parking. This phase of construction activity includes the export of 11,000 cubic yards of soil during excavation. Foundations and concrete pouring would take approximately 12 months to complete and would overlap with the building construction/finishing which would take approximately 30 months. Individual pieces of construction equipment that would likely be used for project construction produce maximum noise levels of 73 dba to 90 dba at a reference distance of 50 feet from the noise source, as shown in Table IV.I 9, Maximum Noise Levels and Estimated Usage of Typical Construction Equipment. Pile driving systems and equipment would not be used. These maximum noise levels would occur when equipment is operating under full power conditions or during impact activities, such as jack hammering or sawing. However, equipment used on construction sites often operate under less than full power conditions, or part power. To more accurately characterize construction period noise levels, the average (Hourly L eq ) noise level associated with each construction stage is calculated based on the quantity, type, and usage factors for each type of equipment that would be used during each construction stage and are typically attributable to multiple pieces of equipment operating simultaneously. Using the conservative industry standard sound attenuation rate of 6 db per doubling of distance for point sources (e.g., construction equipment), the worst case construction period noise levels were estimated at the noise sensitive receptors by phase of construction activity. A summary of noise level increases by receptor location and phase of construction activity is provided in Table IV.I 10, Estimate of Construction Noise Levels at Off Site Sensitive Receiver Locations. The estimated noise levels represent a worst case scenario and the actual sound occurring at various locations would be less than that indicated in Table IV.I 10 due to four factors: 1) the construction activities are analyzed as if they were occurring along the perimeter of the project site, whereas construction would typically occur throughout the site and only periodically at the perimeter of the site; 2) there are times when the construction activities are fewer than the maximums identified here; 3) there are times when the construction equipment operates at less than full power level, and 4) noise sensitive receptors that are located farther away from the project site would experience less construction noise, as sound diminishes away from the source, and due to intervening buildings between the source and receiver. Estimates of the greatest impacts that might occur during construction hours at nearby sensitive receptors are shown in Table IV.I 10. The closest sensitive uses to the project site are a residential unit located across Moreno Drive (R2) and BHHS located adjacent to the south side of the project site (R3). Estimated noise levels are also shown in Table IV.I 10 for a location on Durant Drive approximately 300 feet east of the project site. As indicated in Table IV.I 10, the maximum noise events would exceed the significance threshold limits at the outside locations shown in the table. As also indicated, the sound diminishes with distance. At a distance of 300 feet from the project site, a distance that includes several residential units along Durant Drive and no IV.I 20