1 Willowbrook Court, Suite 120 Petaluma, California Tel: Fax:

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1 1 Willowbrook Court, Suite 120 Petaluma, California Tel: Fax: Mr. Peter McDonnell Principal CMA 1620 Montgomery Street, Suite 320 San Francisco, California Via Subject: Center Street Parking Garage Project, Berkeley, CA Assessment of Operational Noise and Construction Noise and Vibration Dear Mr. McDonnell: The Center Street Parking Garage Project proposes the construction of a new parking garage at 2025 Center Street in Berkeley, California. The existing parking garage located on the site would be demolished and replaced with an eight-level, 711-space parking garage facility. On the first floor, there would be an operation center, small retail spaces, public restrooms, an art display area, and secure bicycle parking. Initially, 24 electric vehicle (EV) charging stations would be included in the proposed project, with the capability of expanding to a total of 57 EV charging stations. Photovoltaic (PV) solar panels would extend 10 feet above the rooftop parking surface, covering approximately 50% of the rooftop parking areas with a structural frame designed to allow expansion to the maximum allowable rooftop coverage (approximately 70 to 80%). The proposed garage would include built-in infrastructure so it can be one of the proposed hubs for a proposed micro-grid under its own preliminary planning stage. The structure s 1,911-square foot operation center would consist of offices, a break room, supply rooms, employee restrooms, and storage. It will be designed to capture rainfall for the garage s irrigational use with a 7,500- gallon cistern and associated built-in infrastructure to contribute captured rainfall to an area-wide solution when it has been defined and developed. The existing noise environment at the surrounding land uses was assessed based on a comparison of project construction and operational noise levels and the City of Berkeley s Noise Ordinance established in the Municipal Code. The results of these comparisons were used to determine specific acoustical recommendations regarding construction noise and vibration control and future operational noise control at sensitive receptor locations in the project vicinity. This report includes a discussion of the ambient noise levels measured at the project site, a summary of construction noise and vibration levels and operational noise levels expected from the proposed

2 project, and a description of measures necessary to reduce noise and vibration levels to acceptable levels. Fundamentals of Environmental Noise Noise may be defined as unwanted sound. Noise is usually objectionable because it is disturbing or annoying. The objectionable nature of sound could be caused by its pitch or its loudness. Pitch is the height or depth of a tone or sound, depending on the relative rapidity (frequency) of the vibrations by which it is produced. Higher pitched signals sound louder to humans than sounds with a lower pitch. Loudness is intensity of sound waves combined with the reception characteristics of the ear. Intensity may be compared with the height of an ocean wave in that it is a measure of the amplitude of the sound wave. In addition to the concepts of pitch and loudness, there are several noise measurement scales which are used to describe noise in a particular location. A decibel (db) is a unit of measurement which indicates the relative amplitude of a sound. The zero on the decibel scale is based on the lowest sound level that the healthy, unimpaired human ear can detect. Sound levels in decibels are calculated on a logarithmic basis. An increase of 10 decibels represents a ten-fold increase in acoustic energy, while 20 decibels is 100 times more intense, 30 decibels is 1,000 times more intense, etc. There is a relationship between the subjective noisiness or loudness of a sound and its intensity. Each 10 decibel increase in sound level is perceived as approximately a doubling of loudness over a fairly wide range of intensities. Technical terms are defined in Table 1. There are several methods of characterizing sound. The most common in California is the A- weighted sound level (dba). This scale gives greater weight to the frequencies of sound to which the human ear is most sensitive. Representative outdoor and indoor noise levels in units of dba are shown in Table 2. Because sound levels can vary markedly over a short period of time, a method for describing either the average character of the sound or the statistical behavior of the variations must be utilized. Most commonly, environmental sounds are described in terms of an average level that has the same acoustical energy as the summation of all the time-varying events. This energy-equivalent sound/noise descriptor is called Leq. The most common averaging period is hourly, but Leq can describe any series of noise events of arbitrary duration. The scientific instrument used to measure noise is the sound level meter. Sound level meters can accurately measure environmental noise levels to within about plus or minus 1 dba. Various computer models are used to predict environmental noise levels from sources, such as roadways and airports. The accuracy of the predicted models depends upon the distance the receptor is from the noise source. Close to the noise source, the models are accurate to within about plus or minus 1 to 2 dba. Since the sensitivity to noise increases during the evening and at night -- because excessive noise interferes with the ability to sleep hour descriptors have been developed that incorporate artificial noise penalties added to quiet-time noise events. The Community Noise Equivalent Level (CNEL) is a measure of the cumulative noise exposure in a community, with a 5 db penalty added to evening (7:00 p.m. - 10:00 p.m.) and a 10 db addition to nocturnal (10:00 p.m. - 2

3 7:00 a.m.) noise levels. The Day/Night Average Sound Level (Ldn) is essentially the same as CNEL, with the exception that the evening time period is dropped and all occurrences during this three-hour period are grouped into the daytime period. Fundamentals of Ground-borne Vibration Ground vibration consists of rapidly fluctuating motions or waves with an average motion of zero. Several different methods are typically used to quantify vibration amplitude. One method is the Peak Particle Velocity (PPV). The PPV is defined as the maximum instantaneous positive or negative peak of the vibration wave. In this report, a PPV descriptor with units of mm/sec or in/sec is used to evaluate construction generated vibration for building damage and human complaints. Table 3 displays the reactions of people and the effects on buildings that continuous vibration levels produce. The annoyance levels shown in Table 3 should be interpreted with care since vibration may be found to be annoying at much lower levels than those shown, depending on the level of activity or the sensitivity of the individual. To sensitive individuals, vibrations approaching the threshold of perception can be annoying. Low-level vibrations frequently cause irritating secondary vibration, such as a slight rattling of windows, doors, or stacked dishes. The rattling sound can give rise to exaggerated vibration complaints, even though there is very little risk of actual structural damage. Construction activities can cause vibration that varies in intensity depending on several factors. The use of pile driving and vibratory compaction equipment typically generates the highest construction related ground-borne vibration levels. Because of the impulsive nature of such activities, the use of the PPV descriptor has been routinely used to measure and assess groundborne vibration and almost exclusively to assess the potential of vibration to induce structural damage and the degree of annoyance for humans. The two primary concerns with construction-induced vibration, the potential to damage a structure and the potential to interfere with the enjoyment of life, are evaluated against different vibration limits. Studies have shown that the threshold of perception for average persons is in the range of to in/sec PPV. Human perception to vibration varies with the individual and is a function of physical setting and the type of vibration. Persons exposed to elevated ambient vibration levels, such as people in an urban environment, may tolerate a higher vibration level. Structural damage can be classified as cosmetic only, such as minor cracking of building elements, or may threaten the integrity of the building. Safe vibration limits that can be applied to assess the potential for damaging a structure vary by researcher and there is no general consensus as to what amount of vibration may pose a threat for structural damage to the building. Construction-induced vibration that can be detrimental to the building is very rare and has only been observed in instances where the structure is at a high state of disrepair and the construction activity occurs immediately adjacent to the structure. 3

4 TABLE 1 Definition of Acoustical Terms Used in this Report Term Definition Decibel, db A unit describing, the amplitude of sound, equal to 20 times the logarithm to the base 10 of the ratio of the pressure of the sound measured to the reference pressure. The reference pressure for air is 20 micro Pascals. Sound Pressure Level Sound pressure is the sound force per unit area, usually expressed in micro Pascals (or 20 micro Newtons per square meter), where 1 Pascal is the pressure resulting from a force of 1 Newton exerted over an area of 1 square meter. The sound pressure level is expressed in decibels as 20 times the logarithm to the base 10 of the ratio between the pressures exerted by the sound to a reference sound pressure (e. g., 20 micro Pascals). Sound pressure level is the quantity that is directly measured by a sound level meter. Frequency, Hz The number of complete pressure fluctuations per second above and below atmospheric pressure. Normal human hearing is between 20 Hz and 20,000 Hz. Infrasonic sound are below 20 Hz and Ultrasonic sounds are above 20,000 Hz. A-Weighted Sound The sound pressure level in decibels as measured on a sound level Level, dba meter using the A-weighting filter network. The A-weighting filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the frequency response of the human ear and correlates well with subjective reactions to noise. Equivalent Noise Level, The average A-weighted noise level during the measurement period. Leq Lmax, The maximum and minimum A-weighted noise level during the Lmin measurement period. L01, L10, L50, The A-weighted noise levels that are exceeded 1%, 10%, 50%, and L90 Day/Night Noise Level, Ldn or DNL Community Noise Equivalent Level, CNEL Ambient Noise Level Intrusive 90% of the time during the measurement period. The average A-weighted noise level during a 24-hour day, obtained after addition of 10 decibels to levels measured in the night between 10:00 p.m. and 7:00 a.m. The average A-weighted noise level during a 24-hour day, obtained after addition of 5 decibels in the evening from 7:00 p.m.to 10:00 p.m. and after addition of 10 decibels to sound levels measured in the night between 10:00 p.m. and 7:00 a.m. The composite of noise from all sources near and far. The normal or existing level of environmental noise at a given location. That noise which intrudes over and above the existing ambient noise at a given location. The relative intrusiveness of a sound depends upon its amplitude, duration, frequency, and time of occurrence and tonal or informational content as well as the prevailing ambient noise level. Source: Handbook of Acoustical Measurements and Noise Control, Harris,

5 TABLE 2 Typical Noise Levels in the Environment Mr. Peter McDonnell, CMA Common Outdoor Activities Noise Level (dba) Common Indoor Activities 110 dba Rock band Jet fly-over at 1,000 feet Gas lawn mower at 3 feet 100 dba Diesel truck at 50 feet at 50 mph 90 dba Food blender at 3 feet Noisy urban area, daytime 80 dba Garbage disposal at 3 feet Gas lawn mower, 100 feet 70 dba Vacuum cleaner at 10 feet Commercial area Heavy traffic at 300 feet 60 dba Normal speech at 3 feet Large business office Quiet urban daytime 50 dba Dishwasher in next room Quiet urban nighttime 40 dba Theater, large conference room Quiet suburban nighttime 30 dba Library Quiet rural nighttime Bedroom at night, concert hall (background) 20 dba 10 dba 0 dba Broadcast/recording studio Source: Technical Noise Supplement (TeNS), California Department of Transportation, September

6 TABLE 3 Reactions of People and Damage to Buildings from or Frequent Intermittent Vibration Levels Velocity Level, Human Reaction Effect on Buildings PPV (in/sec) 0.01 Barely perceptible No effect 0.04 Distinctly perceptible 0.08 Distinctly perceptible to strongly perceptible Vibration unlikely to cause damage of any type to any structure Recommended upper level of the vibration to which ruins and ancient monuments should be subjected 0.1 Strongly perceptible Virtually no risk of damage to normal buildings 0.3 Strongly perceptible to severe Threshold at which there is a risk of damage to older residential dwellings such as plastered walls or ceilings Severe - Vibrations Threshold at which there is a risk of damage to 0.5 considered unpleasant newer residential structures Source: Transportation and Construction Vibration Guidance Manual, California Department of Transportation, September Regulatory Criteria The proposed project would be subject to noise-related regulations, plans, and policies established within documents prepared by the City of Berkeley. These documents are implemented during the environmental review process to limit noise exposure at existing and proposed noise-sensitive land uses. Applicable planning documents include the City of Berkeley Municipal Code. City of Berkeley Municipal Code. Chapter of the City s Municipal Code includes the Community Noise Ordinance for the City and establishes land use-to-land use noise level limits for developed lands with the City of Berkeley, subject to its jurisdiction. Residential exterior noise limits are established in terms of the noise levels which exceed a given level for a cumulative period of more than 30 minutes in any hour, a level which is also considered the median hourly (L50) sound level. The limits are adjusted upward in 5 db increments for sounds of shorter durations: 15 minutes (L25), 5 minutes (L08), 1 minute (L02), or anytime (Lmax) per hour. The following sections of the Noise Ordinance apply to this proposed project: Section Exterior Noise Standards. Maximum permissible sound levels shall be determined by the zoning district of the property subject to the noise, not the property from which the noise originates. 1. The noise standards for the various categories of land use in Table or shall, unless otherwise specifically indicated in other codes, apply to all such property within a designated zone. 2. No person shall operate or cause to be operated any source of sound at any location 6

7 within the incorporated City or allow the creation of any noise on property owned, leased, occupied or otherwise controlled by such person, which causes the sound level when measured on any other property to exceed: a. The noise standard for than land use as specified in Table for a cumulative period of more than 30 minutes in any hour; or b. The noise standard for than land use as specified in Table plus 5 dba for a cumulative period of more than 15 minutes in any hour; or c. The noise standard for than land use as specified in Table plus 10 dba for a cumulative period of more than 5 minutes in any hour; or d. The noise standard for than land use as specified in Table plus 15 dba for a cumulative period of more than 1 minutes in any hour; or e. The noise standard for than land use as specified in Table plus 20 dba for any period time. Table EXTERIOR NOISE LIMITS (Levels not to be exceeded more than 30 minutes any hour) Zoning District Time Period Noise Level (dba) R-1, R-2, R-1A, R-2A, and ESR 7:00 a.m. 10:00 p.m. 10:00 p.m. 7:00 a.m R-3 and above 7:00 a.m. 10:00 p.m :00 p.m. 7:00 a.m. 55 Commercial 7:00 a.m. 10:00 p.m :00 p.m. 7:00 a.m. 60 Industry Anytime If the measured ambient noise level is greater than the level permissible within any of the noise limit categories above, the sound level when measured on any other property shall not exceed: a. The ambient noise level for a cumulative period of more than 30 minutes in any hour; or b. The ambient noise level plus 5 dba for a cumulative period of more than 15 minutes in any hour; or c. The ambient noise level plus 10 dba for a cumulative period of more than 5 minutes in any hour; or d. The ambient noise level plus 15 dba for a cumulative period of more than 1 7

8 minutes in any hour; or e. The ambient noise level plus 20 dba for any period time. 4. If the measurement location is on a boundary between two different zones, the sound level limit applicable to the quieter noise zone shall apply. Section Prohibited Acts. The following acts, and the causing or permitting thereof, are declared to be in violation of this chapter: 6. Loading and Unloading. Loading, unloading, opening, closing or other handling of boxes, crates, containers, building materials, or similar objects between the hours of ten p.m. and seven a.m. such that the sound therefrom across a residential real property line violates the provisions of Section or Construction/Demolition. a. Operating or causing the operation of any tools or equipment used in construction, drilling, repair, alteration, or demolition work before 7:00 a.m. on a weekday (or before 9:00 a.m. on a weekend or holiday) or after 7:00 p.m. on a weekday (or after 8:00 p.m. on a weekend or holiday) such that the sound therefrom across a residential or commercial real property line violates Section or , except for emergency work of public service utilities or by variance issued by the EHD. (This section shall not apply to the use of domestic power tools as specified in subsection B.11 of this section.). b. Noise Restrictions at Affected Properties. Where technically and economically feasible, construction activities shall be conducted in such a manner that the maximum sound levels at affected properties will not exceed those listed in the following schedule: AT RESIDENTIAL PROPERTIES: Mobile Equipment. Maximum sound levels for nonscheduled, intermittent, short-term operation (less than 10 days) of mobile equipment: Weekdays 7:00 a.m. to 7:00 p.m. Weekends 9:00 a.m. to 8:00 p.m. and legal holidays R-1, R-2 Residential Table R-3 and above Multi-Family Residential Commercial/Industrial 75 dba 80 dba 85 dba 60 dba 65 dba 70 dba 8

9 Stationary Equipment. Maximum sound levels for repetitively scheduled and relatively long term operation (period of 10 days or more) of stationary equipment: Weekdays 7:00 a.m. to 7:00 p.m. Weekends 9:00 a.m. to 8:00 p.m. and legal holidays R-1, R-2 Residential Table R-3 and above Multi-Family Residential Commercial/Industrial 60 dba 65 dba 70 dba 50 dba 55 dba 60 dba 8. Vibration. Operating or permitting the operation of any device that creates a vibration, which annoys or disturbs at least two or more reasonable persons of normal sensitiveness who reside in separate residences (including apartments and condominiums) at or beyond the property boundary of the source, if on private property, or at least 150 feet (46 meters) from the source, if on a public space or public right-of-way. 11. Domestic Power Tools, Machinery. a. Operating or permitting the operation of any mechanically powered saw, sander, drill, grinder, lawn or garden tool, or similar tool before 7:00 a.m. on a weekday (or before 9:00 a.m. on a weekend or holiday) or after 7:00 p.m. on a weekday (or after 8:00 p.m. on a weekend or holiday) such that the sound therefrom across a residential or commercial real property line violates Section or b. Any motor, machinery, pump, such as swimming pool equipment, etc., shall be sufficiently enclosed or muffled and maintained so as not to create a Noise Disturbance in accordance with Section or Existing Noise Environment The existing garage is located in a commercially-zoned area in Downtown Berkeley. On Addison Street, the structure adjoins the Freight & Salvage Coffeehouse to the east and the ARTech mixed-use residential building to the west. The Berkeley Repertory Theatre company is located opposite Addison Street from the project site. On the Center Street frontage, office and institutional uses are located to the west, and Berkeley Central, a mixed-use residential building with ground floor retail, resides to the east. Berkeley City College is located to the south, opposite Center Street. A noise monitoring survey was performed in the project site vicinity beginning on Thursday February 4, 2016 and concluding on Tuesday February 9, The monitoring survey included 9

10 four long-term noise measurements, as shown in Figure 1. The noise environment at the site and in the surrounding areas results primarily from vehicular traffic along Addison Street and Center Street. Occasional aircraft associated with Oakland International Airport would also potentially affect the noise environment at the project site. The first long-term noise measurement LT-1 was made approximately 25 feet south of the centerline of Center Street in front of 2002 Center Street. The overall day-night average noise level ranged from 68 to 72 dba Ldn at LT-1 on the weekdays, while ranging from 65 to 66 dba Ldn on the weekend. LT-2 was located approximately 25 feet north of the centerline of Center Street in front of the Berkeley Central mixed-use building. The overall day-night average noise level measured at LT-2 ranged from 69 to 73 dba Ldn on weekdays and from 66 to 68 dba Ldn on the weekends. LT-3 was positioned approximately 20 feet south of the centerline of Addison Street near the Freight & Salvage Coffeehouse. At LT-3, the overall day-night average noise level on the weekdays ranged from 65 to 72 dba Ldn and on the weekends ranged from 63 to 65 dba Ldn. The final long-term measurement LT-4 was made from the rooftop of the existing parking structure and represents ambient noise levels at residences away from Center Street on Addison Street. The overall day-night average noise level at LT-4 ranged from 60 to 65 dba Ldn during the weekdays and was 60 dba Ldn on the weekend. The daily trends for Leq, L2, L8, L25, L50, and Lmax noise levels measured at the long-term locations are shown in Figures 2 through 5, respectively, along with the Ldn values for the 24- hour periods from Thursday, February 4, 2016 through Tuesday, February 9, The average, maximum, and minimum levels during the daytime and nighttime for each long-term measurement are shown in Tables 4 through 7, respectively. Included in each table are the City s noise limits for commercial land uses, which was applied for each monitoring location since the zoning district for all surrounding land uses was identified as C-DMU-Core. 10

11 FIGURE 1 Noise Measurement Locations 11

12 FIGURE 2 Daily Trend in Noise Levels at LT-1, from Thursday, February 4 through Tuesday, February 9, 2016 FIGURE 3 Daily Trend in Noise Levels at LT-2, from Thursday, February 4 through Tuesday, February 9,

13 FIGURE 4 Daily Trend in Noise Levels at LT-3, from Thursday, February 4 through Tuesday, February 9, 2016 FIGURE 5 Daily Trend in Noise Levels at LT-4, from Thursday, February 4 through Tuesday, February 9,

14 TABLE 4 Comparison of LT-1 noise measurements and City of Berkeley Limits Noise Level, dba Type of Level Daytime Nighttime L50 L25 L8 L2 Lmax Limit Average Range Limit Average Range TABLE 5 Comparison of LT-2 noise measurements and City of Berkeley Limits Noise Level, dba Type of Level Daytime Nighttime L50 L25 L8 L2 Lmax Limit Average Range Limit Average Range TABLE 6 Comparison of LT-3 noise measurements and City of Berkeley Limits Noise Level, dba Type of Level Daytime Nighttime L50 L25 L8 L2 Lmax Limit Average Range Limit Average Range TABLE 7 Comparison of LT-4 noise measurements and City of Berkeley Limits Noise Level, dba Type of Level Daytime Nighttime L50 L25 L8 L2 Lmax Limit Average Range Limit Average Range

15 Future Parking Garage Noise According to Section of the City s Noise Ordinance, exterior noise levels should not exceed the established noise limits for commercial land uses shown in Table ; however, if the ambient levels exceed the noise limits, then future exterior noise levels should not exceed the ambient levels. Parking Garage Access Driveway Noise As part of the proposed project, the existing four-story parking structure would be demolished and an eight-story parking structure would be constructed in its place. The reconstructed parking garage would increase the number of parking spaces from 440 to 780. To estimate the total peak hour trips generated by this parking space increase, a traffic study was conducted by Fehr & Peers 1 in June The project-generated trips were estimated to be 91 during the peak AM hour and 153 during the peak PM hour. The proposed garage would be accessible from Addison Street to the north and from Center Street to the south. The traffic study provided peak hour intersection volumes along the surrounding roadways for Existing and Existing Plus Project conditions, and a comparison of these scenarios was conducted to determine how the peak hour project trips would increase traffic noise at the entrances and exits of the proposed garage. Traffic volumes along Addison Street would increase by up to 34% during the peak AM hour and by up to 37% during the peak PM hour. This would result in a traffic noise increase of approximately 1 dba at the north access driveway of the proposed garage. Traffic volumes along Center Street would increase by approximately 9% during both peak AM and PM hours, which would result in a traffic noise increase at the south access driveway of less than 1 dba. Table 8 summarizes the estimated levels at the surrounding land uses, assuming project-generated traffic noise increase at the access driveways. The average noise levels expected in the future under project conditions would not exceed the City s limits for commercial uses. TABLE 8 Estimated ambient noise levels at the surrounding land uses Noise Level, dba Type of Level Daytime Nighttime L50 L25 L8 L2 Lmax Limit LT LT LT LT Limit LT LT LT LT Fehr & Peers, Berkeley Center Street Garage Transportation Impact Analysis, City of Berkeley, CA, June

16 Parking Lot Noise Illingworth & Rodkin, Inc. conducted noise measurements near a four-story parking structure in downtown Petaluma. 2 Noise measurements were made of typical noise-generating activities occurring on the various parking levels. At each parking level, a car door was opened and closed several times, the engine was started, and the auto s horn was sounded. The noise sources were generated at the edge of each story and at a parking stall located about 50 feet from the edge. Noise measurements were also made as a vehicle traveled up and down the parking structure. The loudest noise was generated by a vehicle s horn. Maximum instantaneous noise levels, measured about 75 feet from the façade of the structure at ground level, typically ranged from dba Lmax. Typical noise levels of a car horn ranged from dba Lmax. LT-1 and LT-2 were located approximately 65 and 75 feet, respectively, from the existing parking garage, while LT-3 was approximately 15 feet from the existing garage. At a distance of 65 feet, typical parking lot noise would range from 54 to 59 dba Lmax, and noise levels from a car horn would range from 63 to 71 dba Lmax. At 75 feet, typical parking lot noise would range from 53 to 58 dba Lmax, with car horn noise ranging from 62 to 70 dba Lmax, at LT-2. Estimated levels for parking lot noise at LT-3 would typically range from 67 to 72 dba Lmax, with car horn noise ranging from 76 to 84 dba Lmax. Comparing these estimated noise levels to the measured ambient levels at LT-1, LT-2, and LT-3 (see Tables 4 through 6, respectively), the estimated parking lot noise would fall within the range of existing levels. While the frequency of the noise levels would increase with the proposed parking garage, these events are short in duration and would not exceed either the ambient levels or the noise limits established by the City. The greatest impact due to parking lot noise to the surrounding uses would be to the upper floors of the adjacent residential uses. The existing parking garage is four floors, which means the distance from the rooftop of the existing parking garage to the adjacent residents on floors five through eight would range from approximately 18 to 43 feet. Under future project conditions, each of these residential mixed-use land uses would be approximately 15 feet from the nearest space of the proposed parking garage. LT-4 was taken from the rooftop of the parking garage and represents the existing parking lot noise environment at the adjacent fourth floor residences. The maximum instantaneous noise levels at the fifth floor would range from 44 to 77 dba Lmax during daytime hours and from 41 to 72 dba Lmax during nighttime hours; levels at the sixth floor would range from 43 to 76 dba Lmax during daytime hours and from 40 to 71 dba Lmax during nighttime hours; levels at the seventh floor would range from 42 to 75 dba Lmax during daytime hours and from 39 to 70 dba Lmax during nighttime hours; and levels at the eighth floor would range from 41 to 74 dba Lmax during daytime hours and from 38 to 69 dba Lmax during nighttime hours. Since the existing ambient levels at floors five through eight do not exceed the City s commercial land use noise limits, the Noise Ordinance limits of 85 dba Lmax during daytime hours and 80 dba Lmax during nighttime hours would be maintained at the adjacent residential mixed-use buildings. 2 Environmental Noise Assessment Vallco Fashion Park North Parking Garage prepared for City of Cupertino by Illingworth & Rodkin, Inc., October 11,

17 The future noise levels under worst-case scenario conditions would range from 67 to 72 dba Lmax for typical parking lot activity and from 76 to 84 dba Lmax for car horns at 15 feet. While typical parking lot noise would not exceed the City s noise limits, car horn noise would potentially exceed the nighttime limit by up to 4 dba at each floor. However, these would be unmitigated levels. The eastern and western façades of the parking garage, which are adjacent to the residential mixed-use buildings would consist of either concrete or unfinished concrete masonry walls of at least 8 feet in height. These walls would reduce future noise levels at the shared property lines of the adjacent residences to at or below the City s limits. This would not require further mitigation. At floors above eight at the adjacent mixed-use building, the residences would be exposed to parking lot noise from the rooftop parking level. The ninth floor would be approximately 18 feet from the nearest parking spaces. At this distance, typical parking lot noise levels would range from 65 to 70 dba Lmax, and car horn noise levels would range from 74 to 82 dba Lmax. The proposed parking garage would include solar panels on the roof, which would provide some shielding from the roof deck. Considering the limited number of vehicles expected on the roof deck of the parking garage between 10:00 p.m. and midnight, which is when the parking garage closes, the partial shielding provided by the solar panels would be adequate to meet the City s nighttime limit. Truck Circulation and Loading Activities Two small retail shops are included in the proposed parking garage structure. One small retail shop would be located on the north side of the garage along Addison Street, and a small bike storage operation with a coffee bar would be located on the south side along Center Street. These small retail uses would result in small vendor trucks for deliveries. Additionally, a trash room would be located near both the Addison Street and Center Street entrances. In compliance with Section B6 of the Noise Ordinance and Mitigation Measure NOI-2 of the 2025 Center Street Center Street Garage Project EIR, it is assumed that truck deliveries and garbage truck pick-ups would occur between 7:00 a.m. and 9:00 p.m. The frequency of truck deliveries for these small retail uses are expected to be minimal. The worst-case scenario trash pick-up zone along Addison Street would be within 15 feet of the mixed-use building to the west, approximately 120 feet from the receptors to the east, and approximately 55 feet from the nearest receptors opposite Addison Street. At these distances, the surrounding land uses would be exposed to heavy truck noise ranging from 62 to 85 dba Lmax, which falls within the range of existing ambient levels along Addison Street. The Center Street trash pick-up zone is assumed to be near the trash room in the southeastern corner. At this location, the nearest land uses would be approximately 15 feet to the east, 120 feet to the west, and 65 feet to the south. At these distances, the heavy truck noise would range from 62 to 85 dba Lmax, which falls within the range of existing ambient levels along Center Street. The Addison Street retail delivery zone outside the shop would be approximately 40 to 65 feet from the nearest adjacent land uses and 55 feet from the land uses to the north, opposite the roadway. At these distances, the maximum noise levels at the nearest receptors would range from 63 to 72 dba Lmax. Maximum noise levels generated by backup alarms would be up to 77 dba 17

18 Lmax at these land uses. These noise levels fall within the range of Lmax levels shown in Table 6 for LT-3. The distance from the assumed street-front delivery zone of the bike retail along Center Street to the adjacent land uses would range from 25 to 70 feet, while the land uses to the south, opposite Center Street, would be approximately 65 feet from the delivery zone. At these distances, the maximum noise levels at the nearest receptors would range from 62 to 76 dba Lmax, while backup alarms at these land uses would have maximum noise levels up to 81 dba Lmax. These levels fall within the range of existing ambient levels measured at LT-2 (see Table 5). Mechanical Equipment Noise The proposed project would include mechanical equipment, such as exhaust systems with fans, ventilation, heating units, and air conditioning systems. According to Section B11 of the City s Noise Ordinance, any noise generated by motors, machinery, pumps, etc. should not create a noise disturbance as defined by the exterior and interior noise limits specified in Sections and Since all mechanical equipment is expected to run continuously for a cumulative period of more than 30 minutes in any hour, daytime noise limits of 65 dba L50 and nighttime noise limits of 60 dba L50 for exterior noise should be enforced at the shared property line of adjacent commercial mixed-use receptors. Sound pressure levels were provided for the fan coils, the outdoor air conditioning units, and the fans that would be used in the proposed parking garage. The distance at which the sound pressure levels were measured was not specified; however, it was assumed that the measurements were made at approximately 5 feet. The fan coils and fans would be housed within rooms providing shielding for the adjacent noise-sensitive receptors; however, the following discussion assumes worst-case scenario, which would be unshielded noise levels. The proposed parking garage would include three types of Daikin fan coils and five types of Daikin outdoor air conditioning units. The fan coil units would be located in the ground floor offices, at the Center Street bike retail shop, in the IT room, in the art gallery, and at the future Addison Street retail. According to the site plan specifications, each of the fan coil units would be less than 45 dba Leq at an assumed distance of 5 feet. The distance of each fan coil to the nearest shared property line of an existing noise-sensitive receptor is provided in Table 9. As shown in the table, noise levels from the fan coils would be below the City s 65 dba L50 daytime and 60 dba L50 nighttime limits. 18

19 TABLE 9 Fan Coils Estimated at the Nearest Shared Property Line Fan Noise Level Distance to Nearest Adjacent Estimated Location Coil at 5 feet Shared Property Line Noise Level FC1 Offices <45 dba 35 feet <28 dba FC2 Addison St. Retail <45 dba 45 feet <26 dba FC3 Center St. Bike Retail <45 dba 35 feet <28 dba FC4 IT Room <45 dba 60 feet <23 dba FC5 Art Gallery <45 dba 40 feet <27 dba Each of the outdoor air conditioning units would be located on the second floor of the parking garage. The four units serving the fan coils nearest the Addison Street locations would be in the northwestern corner of the parking garage, and the unit serving the Center Street bike retail shop would be located in the southeastern corner. Assuming the four units along Addison Street would be operating continuously, the combined noise level at an assumed distance of 5 feet would be 59 dba Leq, and the unit along Center Street would have noise levels of 58 dba Leq at an assumed distance of 5 feet. The nearest adjacent residences to these air conditioning units would be approximately 10 feet away, and at this distance, the residences would be exposed to mechanical noise ranging from 52 dba Leq east of the parking garage to 53 dba Leq west of the parking garage. Table 10 summarizes the noise levels for the outdoor air conditioning units. This would not exceed the City s daytime or nighttime noise limits. TABLE 10 Outdoor AC Units HP1 HP2 HP4 HP5 HP3 Outdoor Air Conditioning Units Estimated at the Nearest Shared Property Line Distance to Nearest Noise Level Estimated Location Adjacent Shared Property at 5 feet Noise Level Line Northwest corner of 2 nd floor, along Addison St. Southeast corner of 2 nd floor, along Center St. 49 dba 49 dba 58 dba 49 dba 10 feet 53 dba 58 dba 10 feet 52 dba The fans for the proposed parking garage would be manufactured by the Loren Cook Company. The site plan provided loudness measurements, in sones, for each of the proposed fans, and the sound pressure levels were estimated from the sones values at an assumed distance of approximately 5 feet. These levels are summarized in Table

20 TABLE 11 Fan Units Estimated at the Nearest Shared Property Line Fan Noise Level Distance to Nearest Adjacent Estimated Location Units at 5 feet Shared Property Line Noise Level TF1 Offices 38 dba 30 feet 30 dba EF1 Northeast corner of roof floor, 57 dba 10 feet 54 dba along Addison St. EF2 Southwest corner of roof floor, 62 dba 10 feet 59 dba along Center St. EF3 Sidewalk near the Addison Street Not provided entrance EF4 Generator Room 55 dba 15 feet 50 dba EF5 Addison St. Trash Room 39 dba 10 feet 36 dba EF6 Center St. Trash Room 38 dba 7 feet 37 dba EF7 Elevator Control Room, 4 th floor 51 dba 7 feet 50 dba along Addison St. EF8 Elevator Control Room, 4 th floor along Center St. 51 dba 7 feet 50 dba An inline cabinet fan would serve the fan coil in the offices and would be located on the first floor. The nearest adjacent mixed-use residential land use would be approximately 30 feet from the fan, and noise levels at the shared property line would be 30 dba Leq. Belt drive sidewall fans serving the Addison Street and Center Street restrooms would be located in the northeastern corner and southwestern corner, respectively, on the roof level. Both of these fans would be approximately 10 feet from the nearest shared property line, and at this distance, the fan noise at the adjacent residence to the east would be 54 dba Leq, and the fan noise at the adjacent residence to the west would be 59 dba Leq. These fans would not exceed the City s daytime or nighttime noise limit. Two fans are to be located in the northwestern corner of the proposed parking garage on the first floor: 1) in the generator room; and 2) in the Addison Street trash room. A third fan for the transformer shall be selected by PG&E and would be located on the sidewalk near the entrance. Noise information for the transformer fan was not provided at the time of this study. However, since this fan would be located outside the parking structure along the sidewalk near vehicular traffic noise from Addison Street, the fan noise would not be the dominant noise source. The existing ambient noise levels along Addison Street range from 47 to 74 dba L50 during daytime hours and from 45 to 65 dba L50 during nighttime hours. Typically, fan noise from the transformer would not be expected to exceed these ambient levels. The generator room exhaust fan and Addison Street trash room fan would be approximately 15 and 10 feet, respectively from 20

21 the shared property line to the west. At these distances, the noise levels would be 50 dba Leq generated in the generator room and 36 dba Leq generated in the Addison Street trash room. Noise from these fans would not be additive since each one is located in a separate room. The Center Street trash room would include a fan and would be located on the ground level in the southeastern corner of the proposed parking garage. This fan would be approximately 7 feet from the shared property line, and at this distance, the fan would have noise levels of 37 dba Leq. The final two fans would be in the elevator control rooms on the fourth floor. The Addison Street elevator room fan would be in the northeastern corner, and the Center Street elevator room fan would be in the southwestern corner. The distance to the nearest shared property line would be approximately 7 feet at both locations. The same type of fan would be used at each location, and the estimated noise levels at the shared property line would be 50 dba Leq. For the mechanical equipment information provided at the time of this study, the projectgenerated operational noise would be below the City s daytime and nighttime noise threshold at the shared property lines of the adjacent mixed-use buildings. Since noise information for the transformer fan was not available at the time of this study, calculations for this fan could not be made. This unspecified fan, however, would be in a locked enclosure on the sidewalk near the Addison Street entrance, where traffic noise would be the dominant source. Since noise levels from this fan are not located near the adjacent residences and would not be expected to exceed ambient traffic noise levels along Addison Street, this would be considered a less-thansignificant impact. Construction Noise Noise impacts resulting from construction depend upon the noise generated by various pieces of construction equipment, the timing and duration of noise-generating activities, and the distance between construction noise sources and noise-sensitive areas. Construction noise impacts primarily result when construction activities occur during noise-sensitive times of the day (e.g., early morning, evening, or nighttime hours), the construction occurs in areas immediately adjoining noise-sensitive land uses, or when construction lasts over extended periods of time. Typically, where noise from construction activities exceeds 70 dba Leq and exceeds the ambient noise environment by at least 5 dba Leq at commercial mixed-use land uses in the project vicinity for a period exceeding one year, the impact would be considered significant. The City s Noise Ordinance also includes construction/demolition noise criteria. According to Section B7 of the City of Berkeley Noise Ordinance, maximum sound levels for nonscheduled, intermittent, short-term operation (less than 10 days) of mobile equipment shall not exceed 85 dba Lmax at the commercial mixed-use land uses on weekdays between 7:00 a.m. and 7:00 p.m. or shall not exceed 70 dba Lmax on weekends or holidays between 9:00 a.m. and 8:00 p.m. Maximum sound levels for repetitively scheduled and relatively long-term operation (period of 10 days or more) of stationary equipment shall not exceed 70 dba Lmax on weekdays between 7:00 a.m. and 7:00 p.m. or shall not exceed 60 dba Lmax on weekends and holidays between 9:00 a.m. and 8:00 p.m. Operating any tools or equipment used in construction, drilling, repair, alteration or demolition work on between 7:00 p.m. and 7:00 a.m. on weekdays and between 8:00 p.m. and 9:00 a.m. on weekends and holidays is prohibited. 21

22 Construction noise levels vary on a day-to-day basis depending on the type and amount of equipment operating on site and the specific task that is being completed on a particular day. Construction activities generate considerable amounts of noise, especially during earth-moving activities when heavy equipment is used. The highest maximum noise levels generated by project construction would typically range from about 80 to 90 dba Lmax at a distance of 50 feet from the noise source (Table 12). For the proposed project, pile driving, which generates high noise levels, would not be expected. Typical hourly average construction-generated noise levels for parking garages are about 77 to 89 dba Leq measured at a distance of 50 feet from the center of the site during busy construction periods (e.g., earth moving equipment, impact tools, etc.). The noise levels associated with construction of the interior portions of the garage would be substantially less than the noise levels associated with demolition and structural activities. Construction-generated noise levels drop off at a rate of about 6 dba per doubling of the distance between the source and receptor. Shielding by buildings or terrain can provide an additional 5 to 10 dba noise reduction at distant receptors. The proposed project would be constructed in one phase, which is expected take a maximum of 14 months. Demolition of the existing four-story parking garage would last approximately one month and would utilize hoe rams, saw cutting, and trucks for hauling. This combination of tools would generate maximum instantaneous noise levels of 96 dba Lmax and hourly average noise levels ranging from 79 to 89 dba Leq at a distance of 25 feet. The nearest receptors adjacent to the project site to the east and west would be located within 10 feet of the shared property line. At 10 feet, the maximum noise level would be 103 dba Lmax, and the hourly average noise levels would range from 87 to 97 dba Leq. The distance from the nearest land uses north of the Addison Street to the boundary of the project site would be approximately 55 feet. The distance from the nearest land uses south of the Center Street to the boundary of the project site would be approximately 70 feet. At these distances, the maximum instantaneous noise levels would range from 87 to 89 dba Lmax, and the hourly average noise levels would range from 70 to 82 dba Leq. While the maximum instantaneous noise levels would meet fall within the range of ambient noise levels, the City s limits for construction equipment would be exceeded by up to 33 dba Lmax on the weekends at the adjacent land uses. A detailed equipment list was not provided for the construction of the new parking garage; however, Table 13 presents the typical range of hourly average noise levels generated by different phases of construction, measured at a distance of 50 feet. For a parking garage, hourly average construction-generated noise levels with all pertinent equipment present at the site would range from 77 to 89 dba Leq at a distance of 50 feet during busy construction periods (e.g., earth moving equipment, impact tools, etc.). Using the minimum required equipment, hourly average noise levels would range from 71 to 83 dba Leq during the construction of the parking garage. At the nearest receptors 10 feet to the east and west of the project site, the hourly average noise levels would range from 91 to 103 dba Leq when all equipment is present and from 85 to 97 dba Leq when the minimum required equipment is present. At the land uses 55 feet to the north of Addison Street and 70 feet to the south of Center Street, the hourly noise levels would range from 74 to 88 dba Leq when all equipment is present and from 68 to 82 dba Leq when the minimum required equipment is present. 22

23 The existing land uses surrounding the project site on the north end, along the Addison Street, have ambient hourly noise levels ranging from 60 to 71 dba Leq on the weekdays between 7:00 a.m. and 7:00 p.m. and from 58 to 66 dba Leq on the weekends between 9:00 a.m. and 8:00 p.m. The existing land uses along Center Street have ambient hourly noise levels ranging from 64 to 76 dba Leq on the weekdays and from 60 to 70 dba Leq on the weekends. The residential units adjacent to the site to the east and west located in the upper floors of the nearby buildings have weekday hourly average noise levels ranging from 57 to 63 dba Leq and weekend hourly average noise levels ranging from 55 to 58 dba Leq. Therefore, construction noise levels would exceed 70 dba Leq and would exceed the ambient noise levels by over 5 dba Leq for a total construction duration of up to 14 months. Additionally, individual pieces of equipment would exceed the City s mobile and stationary equipment noise limits at the adjacent land uses. 23