J. NOISE 1. - Amazon S3...frequency response of the human ear and correlates well with subjective reactions to noise. All sound levels in this section are A-weighted, unless reported

L S A A S S O C I A T E S , I N C . J U N E 2 0 1 3

A P P L E C A M P U S 2 P R O J E C T E I R V . S E T T I N G , I M P A C T S A N D M I T I G A T I O N M E A S U R E S

J . N O I S E

P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5j-Noise.docx (06/03/13) PUBLIC REVIEW DRAFT 449

J. NOISE

This section describes existing noise conditions in the vicinity of the project site, describes criteria for determining the significance of noise impacts, and estimates noise levels that would result from implementation of the proposed project. Where appropriate, mitigation measures are recommended to reduce project-related noise impacts. 1. Setting

The setting section begins with an introduction to several key concepts and terms that are used in evaluating noise and vibration, a related issue. This setting section concludes with a description of current noise sources that affect the project area and noise levels that are experienced in the project site vicinity. a. Characteristics of Sound. Noise is generally defined as unwanted sound. Noise consists of any sound that may produce physiological or psychological damage and/or interfere with communication, work, rest, recreation, and sleep. To the human ear, sound has two significant characteristics: pitch and loudness. Pitch is the number of complete vibrations or cycles per second of a wave that results in the range of tone from high to low. Loudness is the strength of a sound that describes a noisy or quiet environment, and it is meas-ured by the amplitude of the sound wave. Loudness is determined by the intensity of the sound waves combined with the reception characteristics of the human ear. Sound intensity refers to how hard the sound wave strikes an object, which in turn produces the sound’s effect. This characteristic of sound can be precisely measured with instruments. The analysis of a project defines the noise environment of the project area in terms of sound intensity and its effects on adjacent sensitive land uses (e.g., residences, nursing homes, schools).

(1) Measurement of Sound. Sound is characterized by various parameters that describe the rate of oscillation (frequency) of sound waves, the distance between successive troughs or crests in the wave, the speed that it travels, and the pressure level or energy content of a given sound. The sound pressure level has become the most common descriptor used to characterize the loudness (or amplitude) of an ambient sound, and the decibel (dB) scale is used to quantify sound intensity. A decibel (dB) is a unit of measurement which indicates the relative intensity of a sound. The 0 point on the dB scale is based on the lowest sound level that the healthy, unimpaired human ear can detect. Changes of 3 dB or less are only perceptible in laboratory environments. Audible increases in noise levels generally refer to a change of 3 dB or more, as this level has been found to be barely percept-ible to the human ear in outdoor environments. Because sound can vary in intensity by over one million times within the range of human hearing, a logarithmic loudness scale1 is used to keep sound intensity numbers at a convenient and manageable level. Thus, a 10 dBA increase in the level of a continuous noise represents a perceived doubling of loudness, while a 20 dBA increase is 100 times more intense, and a 30 dBA increase is 1,000 times more intense. As noise spreads from a source, it loses energy so that the farther away the noise

1 Unlike linear units such as inches or pounds, decibels are measured on a logarithmic scale, representing points on a sharply rising curve. The logarithmic decibel scale allows an extremely wide range of acoustic energy to be characterized in a manageable notation.



J . N O I S E


receiver is from the noise source, the lower the perceived noise level. Noise levels diminish or attenu-ate as distance from the source increases based on an inverse square rule, depending on how the noise source is physically configured. Noise levels from a single-point source, such as a single piece of construction equipment at ground level, attenuate at a rate of 6 dB for each doubling of distance (between the single-point source of noise and the noise-sensitive receptor of concern). Heavily traveled roads with few gaps in traffic behave as continuous line sources and attenuate roughly at a rate of 3 dB per doubling of distance. Since the human ear is not equally sensitive to all pitches (sound frequencies) within the entire spec-trum, a special frequency-dependent rating scale has been devised to relate noise to human sensitivity in a process called “A-weighting,” expressed as “dBA.” The dBA or A-weighted decibel refers to a scale of noise measurement that approximates the range of sensitivity of the human ear to sounds of different frequencies. Table V.J-1 contains a list of typical acoustical terms and definitions. Table V.J-2 shows some representative noise sources and their corresponding noise levels in dBA. There are many ways to rate noise for various time periods, but an appropriate rating of ambient noise affecting humans also accounts for the annoying effects of sound, including during sensitive times of the day and night. The equivalent continuous sound level (Leq) is the total sound energy of time varying noise over a sample period. However, the predominant rating scales in the State of California are the Leq, the community noise equivalent level (CNEL), and the day-night average level (Ldn) based on A-weighted decibels (dBA). CNEL is the time varying noise over a 24-hour period, with a 5 dBA weighting factor applied to the hourly Leq for noises occurring from 7:00 p.m. to 10:00 p.m. (defined as relaxation hours) and a 10 dBA weighting factor applied to noise occurring from 10:00 p.m. to 7:00 a.m. (defined as sleeping hours). Ldn is similar to the CNEL scale, but without the adjustment for events occurring during the evening relaxation hours. CNEL and Ldn are within 1 dBA of each other and are normally exchangeable. The noise adjustments are added to the noise events occurring during the more sensitive hours. Typical A-weighted sound levels from various sources are identified in Table V.J-2. When assessing the annoyance factor, other noise rating scales of importance include the maximum noise level (Lmax), which is the highest exponential time averaged sound level that occurs during a stated time period. The noise environments discussed in this analysis are specified in terms of maxi-mum levels denoted by Lmax for short-term noise events. Lmax reflects peak operating conditions and addresses the annoying aspects of intermittent noise. Noise impacts can be organized into three categories. The first category comprises audible increases in noise levels noticeable to humans. Audible increases in noise levels generally refer to a change of 3.0 dBA or greater, since, as described earlier, this level has been found to be barely perceptible in exterior environments. The second category, potentially audible, refers to a change in the noise level between 1.0 and 3.0 dBA. This range of noise levels has been found to be noticeable only in labora-tory environments. The last category is changes in noise level of less than 1.0 dBA that are inaudible to the human ear. Only audible changes in existing ambient or background noise levels are considered potentially significant.



J . N O I S E


Table V.J-1: Definitions of Acoustical Terms Term Definitions Decibel, dB A unit that denotes the ratio between two quantities proportional to power; the number of

decibels is 10 times the logarithm (to the base 10) of this ratio. Frequency, Hz Of a function periodic in time, the number of times that the quantity repeats itself in one

second (i.e., number of cycles per second). A-Weighted Sound Level, dBA

The sound level obtained by use of A-weighting. 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. All sound levels in this section are A-weighted, unless reported otherwise.

L01, L10, L50, L90 The fast A-weighted noise levels equaled or exceeded by a fluctuating sound level for 1 percent, 10 percent, 50 percent, and 90 percent of a stated time period.

Equivalent Continuous Noise Level, Leq

The level of a steady sound that, in a stated time period and at a stated location, has the same A-weighted sound energy as the time-varying sound.

Community Noise Equivalent Level, CNEL

The 24-hour A-weighted average sound level from midnight to midnight, obtained after the addition of 5 decibels to sound levels occurring in the evening from 7:00 p.m. to 10:00 p.m. and after the addition of 10 decibels to sound levels occurring in the night between 10:00 p.m. and 7:00 a.m.

Day/Night Noise Level, Ldn

The 24-hour A-weighted average sound level from midnight to midnight, obtained after the addition of 10 decibels to sound levels occurring in the night between 10:00 p.m. and 7:00 a.m.

Lmax, Lmin The maximum and minimum A-weighted sound levels measured on a sound level meter, during a designated time interval, using fast time averaging.

Ambient Noise Level

The all-encompassing noise associated with a given environment at a specified time, usually a composite of sound from many sources at many directions, near and far; no particular sound is dominant.

Intrusive The noise that 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: Harris, Cyril M., 1998. Handbook of Acoustical Measurements and Noise Control.

(2) Physiological Effects of Noise. According to the U.S. Department of Housing and Urban Development’s 1985 Noise Guidebook, permanent physical damage to human hearing begins at pro-longed exposure to noise levels higher than 85 to 90 dBA. Exposure to high noise levels affects our entire system, with prolonged noise exposure in excess of 75 dBA increasing body tensions, and thereby affecting blood pressure, functions of the ear, and the nervous system. In comparison, extended periods of noise exposure above 90 dBA would result in permanent cell damage. When the noise level reaches 120 dBA, a tickling sensation occurs in the human ear even with short-term exposure. This level of noise is called the threshold of feeling. To avoid adverse effects on human physical and mental health in the workplace or in communities, the U.S. Department of Labor, Occupational Safety and Health Administration (OSHA) requires the protection of workers from hearing loss when the noise exposure equals or exceeds an 8-hour time-weighted average of 85 dBA.2

2 Occupational Safety & Health Administration, 2011. Regulations, Standards 29 CFR, Occupational Noise

Exposure 1910.95.



J . N O I S E


Unwanted community effects of noise occur at levels much lower than those that cause hearing loss and other health effects. Noise annoyance occurs when it interferes with sleeping, conversation, and noise-sensitive work, including learning or listening to the radio, television, or music. According to World Health Organization (WHO) noise studies, few people are seriously annoyed by daytime activities with noise levels below 55 dBA, or are only moderately annoyed with noise levels below 50 dBA.3 Table V.J-2: Typical A-Weighted Sound Levels

Source: Compiled by LSA Associates, Inc., 2009. b. Characteristics of Groundborne Vibration. Vibrating objects in contact with the ground radiate vibration waves through various soil and rock strata to the foundations of nearby buildings. As the vibration propagates from the foundation throughout the remainder of the building, the vibration of floors and walls may cause perceptible vibration from the rattling of windows or a rumbling noise. The rumbling sound caused by the vibration of room surfaces is called groundborne noise. When

3 World Health Organization, 1999. Guidelines for Community Noise. Website: www.who.int/docstore/peh/noise/

guidelines2.html.



J . N O I S E


assessing annoyance from groundborne noise, vibration is typically expressed as root mean square (rms) velocity in units of decibels of 1 micro-inch per second. To distinguish vibra-tion levels from noise levels, the unit is written as “VdB.” Human perception to vibration in indoor environments starts at levels as low as 67 VdB and sometimes lower. Annoyance due to vibration in residential settings starts at approximately 70 VdB. Groundborne vibration is almost never annoying to people who are outdoors. Although the motion of the ground may be perceived, without the effects associ-ated with the shaking of the building, the motion does not provoke the same adverse human reaction. In extreme cases, excessive groundborne vibration has the potential to cause structural damage to buildings. Construction vibration impacts on building structures are generally assessed in terms of peak particle velocity (PPV). Common sources of groundborne vibration include trains and construction activities such as blasting, pile driving and operating heavy earthmoving equipment. Typical vibration source levels from construction equipment are shown in Table V.J-3. c. Existing Noise Environment. The project site is located in one of the City’s commercial areas, and is bordered to the north by East Homestead Road, to the east by North Tantau Avenue and adjacent commercial uses, to the south by I-280, and to the west by North Wolfe Road. Pruneridge Avenue bisects the site. Beyond these roadways are predominantly commercial and residential uses. The following section describes the existing noise environment and identifies primary noise sources in the vicinity of the project site.

(1) Existing Ambient Noise Levels. Short-term noise monitoring was conducted to establish the existing ambient noise environment at sensitive land uses in the vicinity of the project site. Monitoring locations are shown in Figure V.J-1. Six short-term noise measurements (identified as ST-1 through ST-6) were made on the afternoon of October 25, 2011, between 2:30 p.m. and 5:30 p.m. for periods of 15 minutes each. Noise measure-ment data collected during the short-term noise measurements are summarized in Table V.J-4. The meteorological conditions at the time of noise monitoring are shown in Table V.J-5. The short-term noise measurements show that ambient noise in the project site vicinity ranges from approximately 52 dBA to 71 dBA Leq. Traffic on surrounding roadways is the primary noise source.

Table V.J-3: Typical Vibration Source Levels for Construction Equipment

Equipment PPV at

25 ft (in/sec) Approximate VdB at 25 feet

Pile Driver (impact)

Upper range

1.518 112

Typical 0.644 104

Pile Driver (sonic)

Upper range

0.734 105

Typical 0.170 93 Clam shovel drop (slurry wall)

0.202 94

Hydromill In soil 0.008 66 (slurry wall) In rock 0.017 75 Vibratory roller 0.210 94 Hoe ram 0.089 87 Large bulldozer 0.089 87 Caisson drilling 0.089 87 Loaded trucks 0.076 86 Jackhammer 0.035 79 Small bulldozer 0.003 58

Source: Federal Transit Administration, 2006. Transit Noise and Vibration Impact Assessment. May.



J . N O I S E


Table V.J-4: Short-Term Ambient Noise Monitoring Results, dBA, October 25, 2011 Location Number Location Description

Start Time Leq

a Lmaxb Lmin

c Primary Noise Sources

ST-1 Former HP Building 48 courtyard, center of volleyball court

2:50 p.m. 52.0 54.8 50.8Mechanical noise, people conversing, wind, distant traffic from I-280

ST-2 The Hamptons (apartments), northwest corner of outdoor eating area

3:18 p.m. 64.4 83.1 53.4Traffic on North Wolfe Road and Pruneridge Avenue

ST-3 The Hamptons, southeast corner of basketball court

3:39 p.m. 60.1 72.1 57.2 Traffic on I-280

ST-4 963 Homestead Road, on sidewalk 4:04 p.m. 71.4 78.9 52.2 Traffic on East Homestead Road

ST-5 Property line between Meadow Avenue and 10700 North Tantau Avenue

4:32 p.m. 53.1 62.6 49.2Traffic on North Tantau Avenue and Pruneridge Avenue, parking lot activity

ST-6 Jenny Strand Park, basketball court 5:13 p.m. 59.1 70.4 55.7Traffic on I-280, children playing in park

a Leq represents the average of the sound energy occurring over the 15-minute time period. b Lmax is the highest instantaneous sound level measured during the 15-minute time period. c Lmin is the lowest instantaneous sound level measured during the 15-minute time period. Source: LSA Associates, Inc., October 2011.

Table V.J-5: Meteorological Conditions During Ambient Noise Monitoring

Location Number

Maximum Wind Speed

(mph)

Average Wind Speed

(mph) Temperature

(˚F)

Relative Humidity

(%) Sky

Conditions ST-1 4 2 71 36 Clear ST-2 1 0 77 36 Clear ST-3 3 2 72 41 Clear ST-4 7 3 71 46 Clear ST-5 2 0 69 56 Clear ST-6 3 2 66 63 Clear

Source: LSA Associates, Inc., October 2011.

(2) Existing Aircraft Noise Levels. The public airports nearest to the project site are the San Jose International Airport (5.3 miles northeast of the site), Reid-Hillview of Santa Clara County Airport (12.5 miles east of the site), and Palo Alto Airport (12.5 miles northwest of the site). The nearest private airfield, Moffett Federal Airfield, is located approximately 6.2 miles northwest of the project site. Although aircraft-related noise is occasionally audible on the project site, the site does not lie within an airport land use plan area or within the 60 dBA CNEL noise contours of any of these public airports or private airfields.

(3) Existing Traffic Noise Levels. Existing traffic noise levels were calculated using the Federal Highway Administration (FHWA) Highway Traffic Noise Prediction Model. Traffic data used in the model were obtained from the Transportation Impact Analysis prepared by Fehr & Peers Transportation Consultants for the proposed project.4 The traffic noise model printouts are included in Appendix E.

4 Fehr & Peers Transportation Consultants, 2013. Apple Campus 2 Transportation Impact Analysis.

N W

olf

e R

dN

Wo

lfe

Rd

Forge DrForge Dr

Homestead RdHomestead Rd

Vallco Pkwy

Lorne WayLorne Way

Pruneridge Ave

Ho

wa

rd D

rH

ow

ard

Dr

Pe

ac

oc

k A

ve

Pe

ac

oc

k A

ve

G

iannini Dr

1

2

3

4

5

6

N T

an

tau

Av

eN

Ta

nta

u A

ve

Homestead Rd

Forge Dr

N W

olf

e R

d

N T

an

tau

Av

e

Vallco Pkwy

Lorne Way

Pruneridge Ave

Ho

wa

rd D

r

Pe

ac

oc

k A

ve

G

iannini Dr

Cal

abaz

as C

reek

Cal

abaz

as C

reek

Apple Campus 2 Project Site

Noise Monitoring Location3

feet

6000 300

Apple Campus 2 Project EIRNoise Monitoring LocationsSOURCES: GOOGLE EARTH; LSA ASSOCIATES, INC., 2011.

I:\COC1101 Apple Campus 2\figures\Fig_VJ1.ai (6/3/13)

FIGURE V.J-1



J . N O I S E


This page intentionally left blank.



J . N O I S E


Table V.J-6 lists the calculated traffic noise levels along roadway segments in the project site vicinity under existing conditions. For purposes of assessing impacts, this analysis considers existing condi-tions to be those associated with conditions on the site as of August 2011, at the time the Notice of Preparation was published. Under the August 2011 baseline conditions, approximately 4,844 employees worked on the project site. The current employee numbers on the site reflect Apple’s relocation of its employees in preparation for the project and Hewlett Packard’s consolidation of its employees in Palo Alto. The site has historically operated at its capacity level of 9,800 employees. Therefore, the noise impact analysis, which evaluates the difference between existing and with-project noise levels (including on roadway segments around the project site), represents a conservative approach to evaluating project-related noise impacts. Table V.J-6: Existing Traffic Noise Levels

Roadway Segment

Average Daily Trips a

Centerline to 70 dBA

CNEL (feet)


CNEL (feet)


CNEL (feet)

CNEL(dBA) 50 Feet From

Outermost Lane

1 Homestead Road - Sunnyvale-Saratoga Road to Blaney Avenue 23,300 < 50 90 187 66.4 2 Homestead Road - Blaney Avenue to Wolfe Road 23,600 < 50 90 189 66.4 3 Homestead Road - Wolfe Road to Tantau Avenue 23,900 < 50 91 191 66.5 4 Homestead Road - Tantau Avenue to Lawrence Expressway 20,800 < 50 84 174 65.9 5 Sunnyvale-Saratoga Road - Fremont Avenue to Homestead Road 39,300 79 156 329 69.3 6 DeAnza Boulevard - Homestead Road to I-280 NB Ramps 48,400 89 178 377 70.2 7 DeAnza Boulevard - I-280 SB Ramps to Stevens Creek Boulevard 44,400 85 169 357 69.9 8 Wolfe Road - Fremont Avenue to Homestead Road 24,600 < 50 96 196 65.9 9 Wolfe Road - Homestead Road to Project Entrance 31,800 < 50 112 231 67.0

10 Wolfe Road - Project Entrance to Pruneridge Avenue 31,100 < 50 110 228 66.9 11 Wolfe Road - Pruneridge Avenue to I-280 NB Ramps 38,200 66 125 261 67.8 12 Wolfe Road - I-280 SB Ramps to Vallco Parkway 34,200 63 117 242 67.3 13 Wolfe Road - Vallco Parkway to Stevens Creek Boulevard 24,600 < 50 96 196 65.9 14 Miller Road - Stevens Creek Boulevard to Bollinger Road 17,100 < 50 79 155 64.3 15 Tantau Avenue - Homestead Road to Pruneridge Avenue 9,000 < 50 < 50 99 63.2 16 Tantau Avenue - Pruneridge Avenue to Tandem Drive 9,700 < 50 < 50 104 63.5 17 Tantau Avenue - Tandem Drive to Vallco Parkway 10,400 < 50 52 109 63.8 18 Tantau Avenue - Vallco Parkway to Stevens Creek Boulevard 8,800 < 50 < 50 98 63.1 19 Lawrence Expressway - Homestead Road to Pruneridge Avenue 57,500 140 288 612 72.8 20 Lawrence Expressway - Pruneridge Avenue to Stevens Creek Blvd 56,400 139 284 605 72.7 21 Stevens Creek Boulevard - SR 85 NB Ramps to Stelling Road 33,700 63 116 240 67.2 22 Stevens Creek Boulevard - Stelling Road to De Anza Blvd 28,700 < 50 105 216 66.5 23 Stevens Creek Boulevard - De Anza Boulevard to Wolfe Road 25,600 < 50 99 201 66.1 24 Stevens Creek Boulevard - Wolfe Road to Finch Avenue 21,700 < 50 90 181 65.3 25 Stevens Creek Boulevard - Finch Avenue to Tantau Avenue 23,200 < 50 93 189 65.6 26 Stevens Creek Boulevard - Tantau Avenue to I-280 SB Ramps 27,500 < 50 103 210 66.4 27 DeAnza Boulevard - Stevens Creek Blvd to McClellan Road 12,800 < 50 80 159 64.5 28 DeAnza Boulevard - McClellan Road to Bollinger Boulevard 7,400 < 50 < 50 113 62.1 a Average daily trips are estimated based on the peak hour traffic volumes.b Traffic noise within 50 feet of the roadway centerline requires a site-specific analysis. Note: Shaded cells indicate roadway segments adjacent to the project site.

Source: LSA Associates, Inc., 2012. Results indicate that existing traffic noise levels from modeled roadway segments nearest the project site range from approximately 63 dBA to 67 dBA CNEL as measured at 50 feet from the centerline of the outermost travel lane.



J . N O I S E


In order to analyze the worst case scenario and highest traffic volumes for each of the mod-eled scenarios, PM traffic volumes were used to calculate the Average Daily Traffic (ADT) volumes, as PM volumes were higher overall than the AM traffic volumes. d. Regulatory Framework. The follow-ing section summarizes the regulatory frame-work related to noise, including federal, State and City of Cupertino plans, policies and standards.

(1) U.S. Environmental Protection Agency (U.S. EPA). In 1972, Congress enacted the Noise Control Act. This act authorized the U.S. EPA to publish descrip-tive data on the effects of noise and establish levels of sound “requisite to protect the public welfare with an adequate margin of safety.” These levels are separated into health (hearing loss levels) and welfare (annoyance levels) categories, as shown in Table V.J-7. The U.S. EPA cautions that these identified levels are not standards because they do not take into account the cost or feasibility of the levels. For protection against hearing loss, 96 percent of the population would be protected if sound levels are less than or equal to an Leq(24) of 70 dBA. The “(24)” signifies an Leq duration of 24 hours. The U.S. EPA activity and interfer-ence guidelines are designed to ensure reliable speech communication at about 5 feet in the outdoor environment. For outdoor and indoor environments, interference with activity and annoyance should not occur if levels are below 55 dBA and 45 dBA, respectively. The noise effects associated with an outdoor Ldn of 55 dBA are summarized in Table V.J-8. At 55 dBA Ldn, 95 percent sentence clarity (intelligibility) may be expected at 11 feet, with no substantial community reaction. However, 1 percent of the population may complain about noise at this level and 17 percent may indicate annoyance.

Table V.J-7: Summary of EPA Noise Levels Effect Level Area

Hearing loss Leq(24) < 70 dB All areas. Outdoor activity inter-ference and annoyance

Ldn < 55 dB Outdoors in residential areas and farms and other outdoor areas where people spend widely varying amounts of time and other places in which quiet is a basis for use.

Leq(24) < 55 dB Outdoor areas where people spend limited amounts of time, such as school yards, play-grounds, etc.

Indoor activity interference and annoyance

Leq < 45 dB Indoor residential areas. Leq(24) < 45 dB Other indoor areas with

human activities such as schools, etc.

Source: U.S. Environmental Protection Agency, 1974. Informa-tion on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety. March.

Table V.J-8: Summary of Human Effects in Areas Exposed to 55 dBA Ldn Type of Effects Magnitude of Effect Speech – Indoors

100 percent sentence intelligibility (aver-age) with a 5 dB margin of safety.

Speech – Outdoors

100 percent sentence intelligibility (aver-age) at 0.35 meter.

99 percent sentence intelligibility (average) at 1.0 meter.

95 percent sentence intelligibility (average) at 3.5 meters.

Average Community Reaction

None evident; 7 dB below level of significant complaints and threats of legal action and at least 16 dB below “vigorous action.”

Complaints 1 percent dependent on attitude and other non-level related factors.

Annoyance 17 percent dependent on attitude and other non-level related factors.

Attitude Towards Area

Noise essentially the least important of various factors.

Source: U.S. Environmental Protection Agency, 1974. Informa-tion on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety. March.



J . N O I S E


(2) State of California. The State of California has established regulations that help prevent adverse impacts to occupants of buildings located near noise sources. The “State Noise Insulation Standard” requires noise-sensitive land uses to meet performance standards through design and/or building materials that would offset any noise source in the vicinity of the building. The State has also established land use compatibility guidelines for determining acceptable noise levels for specified land uses. The City of Cupertino has adopted the State’s land use compatibility guidelines, as discussed below and shown in Table V.J-9.

(3) Local Agencies. The project site is located within the City of Cupertino. The project site also borders residential land uses within the jurisdictions of the City of Santa Clara and the City of Sunnyvale. However, the policies and standards of the City of Cupertino are used in this analysis to determine significance findings. The City of Sunnyvale and the City of Santa Clara noise standards have also been used to evaluate the project, but not in determining significance findings. To the extent these neighboring jurisdictions have more stringent standards for noise levels around residential properties, potential impacts have been identified and an explanation of the applicable standard has been provided. The applicable noise policies, standards, and ordinances of the City of Cupertino, upon which a determination of significance findings is based, are summarized as follows.

City of Cupertino. The following section summarizes the regulatory framework established by the City of Cupertino. The City of Cupertino addresses noise in the Noise Element of the General Plan5 and in the Municipal Code.6 The City’s land use compatibility standards for community noise environments are shown in Table V.J-9. According to these standards, environments with noise levels ranging up to 70 dBA CNEL are considered “normally acceptable” for new office and commercial land use development. The policies listed in the Noise Element of the General Plan that are applicable to the proposed project are provided below: Policy 6-51: Freeway Design and Neighborhood Noise

Ensure that roads and development along I-85 and I-280 are designed and improved in a way that minimizes neighborhood noise. Policy 6-53: Neighborhood Need Priority

Review the needs of residents for convenience and safety and make them a priority over the convenient movement of commute or through traffic where practical. Policy 6-54: Traffic Calming Solutions to Street Noise

Evaluate solutions to discourage through traffic in neighborhoods through modified street design. Examples include meandering streets, diverters, landscape islands and wide parking strips Policy 6-58: Commercial Delivery Areas

Be sure new commercial or industrial developments plan their delivery areas so they are away from existing or planned homes.

5 Cupertino, City of, 2005. Cupertino General Plan 2000 – 2020. November 15. 6 Cupertino, City of, 2011. City of Cupertino Municipal Code. September 20.



J . N O I S E


Policy 6-59: Delivery Hours

Actively enforce Section 10.48 of the Municipal Code limiting commercial and industrial delivery hours adjoining residential uses. Policy 6-60: Noise Control Techniques

Require analysis and implementation of techniques to control the effects of noise from industrial equipment and processes for projects near homes. Policy 6-61: Hours of Construction Work

Restrict non-emergency building construction work near homes during evening, early morning, and weekends by enforcing the noise regulations in the Municipal Code. Policy 6-62: Construction and Maintenance Activities

Regulate construction and maintenance activities. Establish and enforce reasonable allowable periods of the day, for weekdays, weekends and holidays for construction activities. Require construction contractors to use only construction equipment incorporating the best available noise control technology Policy 6-63: Sound Wall Requirements

Exercise discretion in requiring sound walls to be sure that all other measures of noise control have been explored and that the sound wall blends with the neighborhood. Sound walls should be landscaped. Policy 6-64: Building Code Sections on Exterior Noise Intrusion

Require the City Building Department to enforce all sections of the California Building Code for exterior sound transmission control (Sec. 1208A.8.1).



J . N O I S E


Table V.J-9: City of Cupertino Noise and Land Use Compatibility Standards

Land Use Category

Community Noise Exposure in Decibels (CNEL) or Day/Night Average Noise Level in Decibels (Ldn) 55 60 65 70 75 80

Residential – Low Density (Single-Family, Duplex, Mobile Homes)

Residential – Multi-Family

Transient Lodging (Motels, Hotels)

Schools, Libraries, Churches, Hospitals, Nursing Homes

Auditoriums, Concert Halls, Amphitheaters

Sports Arena, Outdoor Spectator Sports

Playgrounds, Neighborhood Parks

Golf Courses, Riding Stables, Water Recreation, Cemeteries

Office Buildings, Business Commercial and Professional Centers

Industrial, Manufacturing, Utilities, Agriculture

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.

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.

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

CLEARLY UNACCEPTABLE New construction or development should generally not be undertaken.

Source: Cupertino, City of, 2005. Cupertino General Plan 2000 – 2020. Figure 6-L. November 15.



J . N O I S E


The City of Cupertino further addresses noise in the Municipal Code in Chapter 10.48, Community Noise Control. Section 10.48.040 establishes the acceptable daytime and nighttime maximum noise levels at receiving land uses. The maximum permissible noise level (as measured at receiving sensitive land uses) that may be generated by sources on a nonresidential land use is 55 dBA during nighttime hours and 65 dBA during daytime hours. The maximum permissible noise level that may be generated by sources on a residential land use is 50 dBA during nighttime hours and 60 dBA during daytime hours. Daytime hours are defined to be the period from 7:00 a.m. to 8:00 p.m. on weekdays, and from 9:00 a.m. to 6:00 p.m. on weekends. During the daytime period only, brief noise incidents exceeding established limits are permitted, providing that the sum of the noise duration in minutes plus the excess noise level does not exceed twenty in a 2-hour period. Table V.J-10 shows example combinations of allowable noise level exceedances. Table V.J-10: City of Cupertino Example Maximum Permissible Noise Levels

Noise Increment Above Normal Standard

Noise Duration in 2-Hour Period

5 dBA 15 minutes 10 dBA 10 minutes 15 dBA 5 minutes 19 dBA 1 minute

Source: Cupertino, City of, 2011. City of Cupertino Municipal Code. Section 10.48.040. September 20. According to Section 10.48.051 of the Municipal Code, the use of motorized equipment for landscape maintenance activities is limited to the hours of 8:00 a.m. to 8:00 p.m. on weekdays, and 9:00 a.m. to 6:00 p.m. on weekends and holidays for the proposed project. During these hours, noise from the use of motorized equipment for landscape maintenance activities is allowed to exceed the maximum permissible noise limits of Section 10.48.040 of the Municipal Code, provided that the equipment is outfitted with appropriate mufflers and is operated over the minimal period necessary. According to Section 10.48.053 of the Municipal Code, noise from grading, construction, and demoli-tion activities is also allowed to exceed the maximum permissible noise limits described above (with examples given in Table V.J-10), provided that the equipment utilized is outfitted with high-quality mufflers and abatement devices and is in good condition. In addition, noise-producing construction activities must meet one of the following criteria:

No individual device produces a noise level of more than 87 dBA Lmax as measured at a distance of 25 feet; or

The operation of such equipment does not produce noise levels that exceed 80 dBA Lmax as measured at any nearby property.

Except for emergency work, construction activities including grading, street construction, demolition, or underground utility work are not permitted within 750 feet of a residential area on Saturdays, Sundays, and holidays, and during the nighttime period. Construction activities, other than street construction, are prohibited on holidays (which include New Year’s Day, Memorial Day, Independ-ence Day, Labor Day, Thanksgiving Day, and Christmas Day). In addition, construction activities, other than street construction, are prohibited during nighttime periods unless they meet the City’s nighttime maximum permissible noise level standards.



J . N O I S E


The City’s land use activity and site development regulations in Section 19.56.060 of the Municipal Code address noise standards for new commercial construction that adjoins a residential district. Because the City has determined that the project meets the definition of a commercial use (Section 10.48.062), these standards apply to the project. The construction of new buildings on properties adjoining a residential district must include the following noise attenuation features:

Exterior walls must be designed to attenuate all noise emanating from interior retail space.

Loading docks and doors must be located away from residential districts. Required fire doors are excluded.

Air conditioning, exhaust fans, and other mechanical equipment must be acoustically isolated to comply with the Noise Ordinance.

A minimum 8-foot-high masonry sound wall must be installed on or adjacent to the common property line between a retail and residential property, to the extent feasible consistent with existing landscaping. Wall height is measured from the property with the highest finish grade.

2. Impacts and Mitigation Measures

This section evaluates potential noise impacts associated with implementation of the proposed project and mitigation measures to address these impacts, where appropriate. a. Criteria of Significance. A project would have a significant noise effect if it would substan-tially increase the ambient noise levels of adjoining areas or conflict with adopted environmental plans and goals of applicable regulatory agencies. For the purposes of this EIR, the project would result in a significant noise impact if it would:

Expose persons to or generate noise levels in excess of standards established in the General Plan, Noise Ordinance, or applicable standards of regulatory agencies;

Create a substantial permanent increase in ambient noise levels in the project site vicinity above levels existing without the project;

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

Expose persons to or generate excessive ground-borne vibration or ground-borne noise levels;

For a project located within an airport land use plan or, where such a plan has not been adopted, within 2 miles of a public airport or public use airport, expose people residing or working in the project area to excessive noise levels; or

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

For the purposes of this analysis, a substantial permanent increase in ambient noise levels is consid-ered to be more than 3 dBA. This criterion is based on the fact that 3 dBA is the smallest change that has been found to be barely perceptible to the human ear in outdoor environments. In addition, for purposes of this analysis, a substantial temporary or periodic increase in ambient noise levels is



J . N O I S E


considered to be more than 5 dBA, as a change of 5 dBA is considered the smallest change that is readily perceptible in outdoor environments. b. Less-Than-Significant Impacts. The less-than-significant impacts of the project on noise are discussed below.

(1) Expose Persons to or Generate Noise Levels in Excess of Applicable Standards. Implementation of the proposed project would result in less-than-significant noise impacts associated with project-related stationary noise sources, and exposure of persons within the site to traffic-related noise, as discussed in detail below.

Stationary Noise. As described in the regulatory framework discussion above, the City of Cupertino has established maximum permissible noise levels that may be generated by sources on a nonresidential land use. These maximum levels are 55 dBA during nighttime hours and 65 dBA during daytime hours, as measured at a receiving sensitive land use. (Daytime hours are defined to be the period from 7:00 a.m. to 8:00 p.m. on weekdays, and from 9:00 a.m. to 6:00 p.m. on weekends.) The maximum permissible noise level that may be generated by sources on a residential land use is 50 dBA during nighttime hours and 60 dBA during daytime hours. Similarly, the City of Santa Clara has established maximum acceptable noise levels at a receiving residential land use of 55 dBA between the hours of 7:00 a.m. and 10:00 p.m., and 50 dBA between the hours of 10:00 p.m. and 7:00 a.m. However, if the measured ambient noise level at a given location differs from the maximum allowa-ble noise standard, the allowable noise exposure standard should be adjusted in 5 dBA increments for that land use category to encompass or reflect the measured existing ambient noise level. The City of Sunnyvale has established that operational maximum noise limits must not exceed 75 dBA at any point on the property line of the premises upon which the noise or sound is generated or produced, provided that the noise or sound level does not exceed 50 dBA during nighttime hours or 60 dBA during daytime hours at any point on adjacent residentially-zoned property. On-site office and research and development uses would contain stationary noise sources such as mechanical equipment, occasional truck delivery loading/unloading activities, transit center load-ing/unloading activities, and typical parking lot activities. These activities are potential point sources of noise that could affect noise-sensitive receptors in the project site vicinity. Of the on-site stationary noise sources, noise generated by delivery truck activity would generate the highest maximum noise levels. While parking activities, such as people conversing or doors slam-ming, would generate noise levels of approximately 60 dBA to 70 dBA Lmax at 50 feet, delivery truck loading and unloading activities would result in maximum noise levels from 75 dBA to 85 dBA Lmax at 50 feet. There are generally two types of loading that would occur on the site: small deliveries like parcels and packages, and large deliveries such as major retail items, weekly food deliveries for the dining facility, or bulk supplies for the proposed office and research and development facilities. The former are typically made via passenger car, van, or single-unit truck. Deliveries to the Main Building would occur primarily via the underground parking area and deliver-ies to the buildings adjacent to North Tantau Avenue are anticipated to occur via surface parking or indoor parking areas. The closest noise-sensitive receptors to potential project delivery loading areas



J . N O I S E


at the Phase 2 Buildings include the single-family residential land uses on Howard Drive and Meadow Avenue. The outdoor active use areas (backyards) of these residences are located approxi-mately 70 feet from the nearest potential small delivery loading and unloading areas. However, there is an existing 6-foot block wall along the project site property line that would effectively reduce noise from the delivery loading operations by a minimum of 6 to 8 dBA at the nearest receiving residential units. Therefore, noise levels from delivery loading and unloading activities at the proposed buildings east of North Tantau Avenue could range up to 61 dBA Lmax intermittently at the nearest residential outdoor active use areas. These noise levels are similar to what is currently experienced at these land uses from existing delivery activity operations on the project site. Therefore, as project-related delivery activity noise levels would not exceed existing noise levels as measured at receiving sensitive land uses, this impact would be less than significant. All other project delivery and loading/unloading areas would occur in the project’s underground parking structures, and would therefore not adversely affect sensitive receptors in the project site vicinity. Activities in the underground parking structure would not be audible at residential uses surrounding the project site. The proposed project would also include new mechanical noise sources, including the proposed Central Plant, as well as heating-air-conditioning-and-ventilation (HVAC) systems on each building. The proposed Central Plant would be located in the southwest corner of the project site adjacent to the Main Parking Structure. The closest sensitive receptors to this facility would be the residents at The Hamptons, approximately 350 feet away. Outdoor equipment associated with the Central Plant would include cooling towers, fuel cells, and emergency generators. However, the mechanical equipment at the Central Plan would be designed such that associated noise would not be audible at The Hamptons. Noise attenuation would be achieved in the following ways:

Central Plant doors would be insulated to reduce noise transmission, and ventilation paths to interior spaces would include sound attenuators and acoustic louvers.

The cooling towers would be located in a well between the Main Parking Structure and the Central Plant that would be surrounded by a solid wall on all sides. In addition, nighttime operation would be optimized to reduce cooling tower activity and associated noise.

The fuel cells would be located to the south of the Main Parking Structure, such that the Main Parking Structure would block associated noise emanating towards The Hamptons.

The emergency generators, which would be located to the east of the fuel cells, would be enclosed in a sound-attenuating, weather-proof enclosure. Periodic testing of the generators would be designed to limit disturbance to nearby residential uses.

With these noise-reducing features, combined with the distance from the Central Plant to The Hamptons, noise levels from operations of the Central Plant would be reduced to below the existing ambient background noise levels, which are influenced by traffic noise on North Wolfe Road and I-280. Each of the proposed project buildings would also include HVAC systems that contain exterior mechanical equipment such as compressors and fans. In addition, Satellite Plant South and Satellite Plant north would also include noise-generating mechanical equipment. However, due to existing



J . N O I S E


ambient noise levels in the project vicinity (which are dominated by noise from traffic on local roadways and on I-280) and due to the distance of the proposed facilities from off-site sensitive receptors, noise from the operation of these types of mechanical equipment would attenuate to below ambient noise levels as measured at receiving sensitive land uses. Therefore, as project-related mechanical equipment stationary noise sources would not exceed existing ambient noise levels at receiving sensitive land uses, impacts of mechanical equipment on the noise environment would be considered less than significant.

Traffic Noise. Implementation of the proposed project would result in increased traffic noise levels in the project site vicinity. The FHWA highway traffic noise prediction model (FHWA RD-77-108) was used to evaluate traffic-related noise conditions in the vicinity of the project site. The resultant noise levels were weighed and summed over a 24-hour period in order to determine the CNEL values. The existing and cumulative (year 2020) traffic volumes for roadway segments in the project site vicinity were used in the traffic noise impact analysis. Table V.J-11 and Table V.J-12 show the traffic noise levels for each scenario as calculated at 50 feet from the centerline of the outermost travel lanes. The model inputs and outputs, including the 60 dBA, 65 dBA, and 70 dBA noise contour distances for each modeled roadway segment, are provided in Appendix E. A significant impact would occur if the project would expose persons within the project site to noise levels in excess of standards established in the General Plan, Noise Ordinance, or applicable standards of regulatory agencies. Traffic noise levels on modeled roadway segments of East Homestead Road, North Wolfe Road, and North Tantau Avenue that are adjacent to the project site would range from 64.8 dBA to 69.3 dBA CNEL at 50 feet from the centerline of the outermost travel lane under Cumulative (2020) Plus Project conditions. These noise levels are below the City’s “normally acceptable” land use compatibility standard (shown in Table V.J-9) of 70 dBA CNEL for new office land use development. Therefore, the project would not expose employees on the site to noise levels that exceed the City’s land use compatibility standards for office uses and the impact would be considered less than significant.

(2) Create a Substantial Permanent Increase in Ambient Noise Levels. The proposed project would generate traffic and stationary noise during the operation period that could result in a permanent increase in ambient noise levels. Potential impacts associated with these noise sources are discussed below, but are less than significant.

Traffic Noise. As discussed above, the results of the FHWA highway traffic noise prediction model for existing and cumulative (year 2020) traffic conditions on roadway segments in the project site vicinity are shown in Table V.J-11 and Table V.J-12, respectively.



J . N O I S E


Table V.J-11: Existing and Existing Plus Project Traffic Noise Levels, dBA CNEL

Roadway Segment

Most Noise Sensitive

Adjacent Land Use

Normally Acceptable Land Use

Compatibility Standard Existing

Existing + Project

Change from

Existing to Existing + Project

(dBA)

Existing Traffic Noise in Excess of Standard?1

Significant Impact Under

Existing + Project

Conditions? 2

1 Homestead Road - Sunnyvale-Saratoga Road to Blaney Avenue SF Residential 60 66.4 66.7 0.3 Yes No2 Homestead Road - Blaney Avenue to Wolfe Road SF Residential 60 66.4 66.8 0.4 Yes No3 Homestead Road - Wolfe Road to Tantau Avenue SF Residential 60 66.5 67.6 1.1 Yes No4 Homestead Road - Tantau Avenue to Lawrence Expressway SF Residential 60 65.9 66.2 0.3 Yes No5 Sunnyvale-Saratoga Road - Fremont Avenue to Homestead Road MF Residential 65 69.3 69.4 0.1 Yes No6 DeAnza Boulevard - Homestead Road to I-280 NB Ramps MF Residential 65 70.2 70.3 0.1 Yes No7 DeAnza Boulevard - I-280 SB Ramps to Stevens Creek Boulevard SF Residential 60 69.9 69.9 0.0 Yes No8 Wolfe Road - Fremont Avenue to Homestead Road SF Residential 60 65.9 66.1 0.2 Yes No9 Wolfe Road - Homestead Road to Project Entrance Office 70 67.0 68.0 1.0 No No

10 Wolfe Road - Project Entrance to Pruneridge Avenue Office 70 66.9 68.9 2.0 No No11 Wolfe Road - Pruneridge Avenue to I-280 NB Ramps MF Residential 65 67.8 69.2 1.4 Yes No12 Wolfe Road - I-280 SB Ramps to Vallco Parkway Commercial 70 67.3 68.0 0.7 No No13 Wolfe Road - Vallco Parkway to Stevens Creek Boulevard Commercial 70 65.9 66.3 0.4 No No14 Miller Road - Stevens Creek Boulevard to Bollinger Road SF Residential 60 64.3 64.4 0.1 Yes No15 Tantau Avenue - Homestead Road to Pruneridge Avenue Office 70 63.2 63.9 0.7 No No16 Tantau Avenue - Pruneridge Avenue to Tandem Drive Office 70 63.5 65.8 2.3 No No17 Tantau Avenue - Tandem Drive to Vallco Parkway Office 70 63.8 66.3 2.5 No No18 Tantau Avenue - Vallco Parkway to Stevens Creek Boulevard Office 70 63.1 65.1 2.0 No No19 Lawrence Expressway - Homestead Road to Pruneridge Avenue SF Residential 60 72.8 72.9 0.1 Yes No20 Lawrence Expressway - Pruneridge Avenue to Stevens Creek Boulevard SF Residential 60 72.7 72.9 0.2 Yes No21 Stevens Creek Boulevard - SR 85 NB Ramps to Stelling Road Commercial 70 67.2 67.3 0.1 No No22 Stevens Creek Boulevard - Stelling Road to De Anza Boulevard Commercial 70 66.5 66.6 0.1 No No23 Stevens Creek Boulevard - De Anza Boulevard to Wolfe Road MF Residential 65 66.1 66.3 0.2 Yes No24 Stevens Creek Boulevard - Wolfe Road to Finch Avenue Commercial 70 65.3 65.7 0.4 No No25 Stevens Creek Boulevard - Finch Avenue to Tantau Avenue MF Residential 65 65.6 66.0 0.4 Yes No26 Stevens Creek Boulevard - Tantau Avenue to I-280 SB Ramps SF Residential 60 66.4 67.1 0.7 Yes No27 DeAnza Boulevard - Stevens Creek Boulevard to McClellan Road Commercial 70 64.5 64.5 0.0 No No28 DeAnza Boulevard - McClellan Road to Bollinger Boulevard Commercial 70 62.1 62.1 0.0 No No

Note: Shaded cells indicate roadway segments adjacent to the project site. SF = single-family; MF = multi-family. 1 Roadway segments that, under existing conditions, experience traffic noise levels in excess of normally acceptable land use compatibility standards for the adjacent noise

sensitive land uses. 2 A significant project impact is defined to be a 3 dBA or greater increase in traffic noise levels compared to conditions without the project. A significant project impact would

also occur if traffic noise levels along roadway segments adjacent to the project site would exceed normally acceptable standards for the proposed project land uses.

Source: LSA Associates, Inc., 2013.



J . N O I S E


Table V.J-12: Cumulative and Cumulative Plus Project Traffic Noise Levels, dBA CNEL

Roadway Segment

Most Noise Sensitive

Adjacent Land Use

Normally Acceptable Land Use

Compatibility Standard

Cumulative(2020)

No Project

Cumulative(2020)

+ Project

Change from

Cumulativeto Cumulative

+ Project (dBA)

Cumulative + Project Traffic Noise in

Excess of Standard?

Significant Contribution

to a Cumulative Impact? 1

1 Homestead Road - Sunnyvale-Saratoga Road to Blaney Avenue SF Residential 60 66.7 67.0 0.3 Yes No2 Homestead Road - Blaney Avenue to Wolfe Road SF Residential 60 66.5 66.9 0.4 Yes No3 Homestead Road - Wolfe Road to Tantau Avenue SF Residential 60 66.9 67.9 1.0 Yes Yes4 Homestead Road - Tantau Avenue to Lawrence Expressway SF Residential 60 66.3 66.7 0.4 Yes No5 Sunnyvale-Saratoga Road - Fremont Avenue to Homestead Road MF Residential 65 69.8 69.8 0.0 Yes No6 DeAnza Boulevard - Homestead Road to I-280 NB Ramps MF Residential 65 70.6 70.7 0.1 Yes No7 DeAnza Boulevard - I-280 SB Ramps to Stevens Creek Boulevard SF Residential 60 70.3 70.3 0.0 Yes No8 Wolfe Road - Fremont Avenue to Homestead Road SF Residential 60 66.5 66.7 0.2 Yes No9 Wolfe Road - Homestead Road to Project Entrance Office 70 67.4 68.3 0.9 No No

10 Wolfe Road - Project Entrance to Pruneridge Avenue Office 70 67.4 69.3 1.9 No No11 Wolfe Road - Pruneridge Avenue to I-280 NB Ramps MF Residential 65 68.3 69.5 1.2 Yes Yes12 Wolfe Road - I-280 SB Ramps to Vallco Parkway Commercial 70 69.4 69.8 0.4 No No13 Wolfe Road - Vallco Parkway to Stevens Creek Boulevard Commercial 70 67.0 67.3 0.3 No No14 Miller Road - Stevens Creek Boulevard to Bollinger Road SF Residential 60 65.1 65.1 0.0 Yes No15 Tantau Avenue - Homestead Road to Pruneridge Avenue Office 70 64.1 64.8 0.7 No No16 Tantau Avenue - Pruneridge Avenue to Tandem Drive Office 70 64.3 66.3 2.0 No No17 Tantau Avenue - Tandem Drive to Vallco Parkway Office 70 64.8 66.9 2.1 No No18 Tantau Avenue - Vallco Parkway to Stevens Creek Boulevard Office 70 64.7 66.1 1.4 No No19 Lawrence Expressway - Homestead Road to Pruneridge Avenue SF Residential 60 73.5 73.5 0.0 Yes No20 Lawrence Expressway - Pruneridge Avenue to Stevens Creek Boulevard SF Residential 60 73.4 73.6 0.2 Yes No21 Stevens Creek Boulevard - SR 85 NB Ramps to Stelling Road Commercial 70 67.7 67.7 0.0 No No22 Stevens Creek Boulevard - Stelling Road to De Anza Boulevard Commercial 70 67.2 67.2 0.0 No No23 Stevens Creek Boulevard - De Anza Boulevard to Wolfe Road MF Residential 65 67.3 67.4 0.1 Yes No24 Stevens Creek Boulevard - Wolfe Road to Finch Avenue Commercial 70 67.2 67.4 0.2 No No25 Stevens Creek Boulevard - Finch Avenue to Tantau Avenue MF Residential 65 67.3 67.7 0.4 Yes No26 Stevens Creek Boulevard - Tantau Avenue to I-280 SB Ramps SF Residential 60 68.0 68.6 0.6 Yes No27 DeAnza Boulevard - Stevens Creek Boulevard to McClellan Road Commercial 70 65.1 65.1 0.0 No No28 DeAnza Boulevard - McClellan Road to Bollinger Boulevard Commercial 70 62.3 62.3 0.0 No No

Note: Shaded cells indicate roadway segments adjacent to the project site. SF = single-family; MF = multi-family. 1 This is defined to be a 1 dBA or greater increase in traffic noise levels compared to conditions without the project for any segment that would also experience traffic noise

levels under cumulative plus project conditions that exceed normally acceptable land use compatibility thresholds for the adjacent land uses.


Cal

abaz

as C

reek

N T

anta

u A

veN

Tan

tau

Ave

N W

olf

e R

dN

Wo

lfe

Rd

N D

eAn

za B

lvd

N D

eAn

za B

lvd

S D

eAn

za B

lvd

S D

eAn

za B

lvd

N B

lan

ey A

veN

Bla

ney

Ave

Su

nn

yval

e-S

arat

og

a R

dS

un

nyv

ale-

Sar

ato

ga

Rd

N W

olf

e R

dN

Wo

lfe

Rd

S W

olf

e R

dS

Wo

lfe

Rd

N T

anta

u A

veN

Tan

tau

Ave

Mill

er A

veM

iller

Ave

Law

ren

ce E

xpre

ssw

ayL

awre

nce

Exp

ress

way

Homestead RdHomestead Rd

Stevens Creek BlvdStevens Creek Blvd

Cal

abaz

as C

reek

Pruneridge Ave

Pruneridge Ave

N D

eAn

za B

lvd

S D

eAn

za B

lvd

N B

lan

ey A

ve

Su

nn

yval

e-S

arat

og

a R

d

N W

olf

e R

dS

Wo

lfe

Rd

N T

anta

u A

ve

Mill

er A

ve

Law

ren

ce E

xpre

ssw

ay

Homestead Rd

Stevens Creek Blvd

Cal

abaz

as C

reek

Pruneridge Ave

Pruneridge Ave

feet

12000 600Increases of 2 dBA to 3 dBA

Increases of 1 dBA to 2 dBA

Increases of less than 1 dBA

Project Boundary

FIGURE V.J-2

SOURCES: GOOGLE EARTH, 11/01/11; LSA ASSOCIATES, INC., 2013.


Apple Campus 2 Project EIRPredicted Traffic Noise Level Changesfrom Existing to Existing Plus Project

N T

anta

u Av

eN

Tan

tau

Ave

N W

olfe

Rd

N W

olfe

Rd

Law

renc

e E

xpre

ssw

ayLa

wre

nce

Exp

ress

way

Pruneridge AvePruneridge AveN

Bla

ney

Ave

N B

lane

y Av

e

Mill

er A

veM

iller

Ave

Stevens Creek BlvdStevens Creek Blvd

N D

eAnz

a B

lvd

N D

eAnz

a B

lvd

Sunn

yval

e-Sa

rato

ga R

dSu

nnyv

ale-

Sara

toga

Rd

H RH R

S W

olfe

Rd

S W

olfe

Rd

S D

eAnz

a B

lvd

S D

eAnz

a B

lvd

N D

eAnz

a B

lvd

S D

eAnz

a B

lvd

N B

lane

y Av

e

Sunn

yval

e-Sa

rato

ga R

d

N W

olfe

Rd

S W

olfe

Rd

N T

anta

u Av

e

Mill

er A

ve

Law

renc

e E

xpre

ssw

ay

H R

Stevens Creek Blvd

Pruneridge Ave

feet

12000 600



Increases of less than 1 dBA

Project Boundary Segments with Cumulative Plus Project TrafficNoise Levels in Excess of Normally AcceptableThreshold for Adjacent Land Uses

Significant Impact Under CumulativeConditions

FIGURE V.J-3

SOURCES: GOOGLE EARTH, 11/01/11; LSA ASSOCIATES, INC., 2013.


Apple Campus 2 Project EIRPredicted Traffic Noise Level Changes

from Cumulative to Cumulative Plus Project



J . N O I S E


The City of Cupertino has established that a significant impact would occur if the project would permanently increase ambient exterior noise levels by more than 3 dBA over levels existing without the project as measured at noise sensitive receptors in the project vicinity. The greatest increase in noise under existing conditions would be a 2.5 dBA increase in traffic noise levels along Tantau Avenue from Tandem Drive to Vallco Parkway under Existing Plus Project conditions. This increase would not be perceptible in an outdoor environment and is below the significance threshold of a greater than 3 dBA increase. Based on these results, project-related traffic noise levels would not result in a permanent significant increase in ambient noise levels compared to those existing without the project. Thus, project-related traffic noise impacts on off-site sensitive land uses would not exceed the City’s significance criteria and would therefore be less than significant.

Stationary Noise. As discussed in the impact analysis discussion for the first significance crite-rion, above, noise levels from delivery loading and unloading activities at the proposed Phase 2 Buildings east of North Tantau Avenue would be similar to what is currently experienced at these land uses from existing delivery activity operations on the project site. All other project delivery loading and unloading areas would occur in the project’s underground parking structures, and would therefore not affect sensitive receptors in the project vicinity. Therefore, project-related delivery loading and unloading activities would not result in a significant increase in ambient noise levels and this impact would be less than significant. Similarly, noise from new mechanical noise sources, including the proposed Central Plant as well as HVAC systems would be reduced to below the existing ambient background noise levels (due primarily to distance attenuation and design features, such as walls, insulated doors, and noise attenuated ventilation shafts). Therefore, as project-related mechanical equipment stationary noise sources would not exceed existing ambient noise levels at receiving sensitive land uses, this impact would be considered less than significant.

(3) Expose Persons to or Generate Excessive Groundborne Vibration or Groundborne Noise Levels. Operation of the project would not be expected to generate substantial vibration based on the types of land uses that would occupy the project site (office and research and development uses). No permanent noise sources that would expose persons to excessive groundborne vibration or noise levels would be located within the project site. However, construction activities related to development of the proposed project could result in groundborne vibration levels that would be perceptible at points along the project site property line when heavy earthmoving equipment operates near the periphery of the site. The City of Cupertino does not have policies or standards that specifically address groundborne vibration impacts. Therefore, for the purpose of this analysis, the generally-accepted standards established by the Federal Transit Administration (FTA) 7 will be used as the impact thresholds for impacts within the City of Cupertino. The City of Santa Clara Municipal Code restricts uses, activi-ties, and processes from generating groundborne vibration that would be perceptible at any point along or beyond the property line of the parcel containing the activity. The City of Sunnyvale Municipal Code establishes that no activity or operation may be permitted to generate vibration that

7 Federal Transit Administration, 2006. Transit Noise and Vibration Impact Assessment. May.



J . N O I S E


would be perceptible to an individual at any point on the property line of the premises of the vibration source, without the use of a special measuring device. The vibration level at a distance from a source can be calculated using the following propagation formula (this formula is based on point sources with normal propagation conditions):

PPVequip = PPVref x (25/D)1.5

where: PPVequip is the peak particle velocity in inches per second (in/sec) of the equipment adjusted for distance;

PPVref is the reference vibration level in in/sec at 25 feet; and

D is the distance from the equipment to the receiver measured in feet. Pile driving can be a potential source of groundborne vibration. However, the project would not employ pile driving as a construction method. Typical groundborne vibration levels from heavy construction equipment in full operation, such as heavy roller compactors, can range up to 0.21 PPV as measured at a distance of 25 feet from the operating equipment. The closest vibration-sensitive receptors to the project site boundaries include the single-family residential land uses on Howard Drive and Meadow Avenue, whose rear property lines would be located adjacent to the proposed buildings on the east side of North Tantau Avenue. These properties are located within the City of Santa Clara. Operation of heavy construction equipment, such as backhoes for landscaping work, is anticipated to occur as close as 10 feet from the property line; heavier construction equipment, such as excavators or vibratory rollers, would operate as close as 30 feet from the property line. The outdoor active use areas (backyards) of these residences immediately border the project site, while the nearest façades are located within 25 feet of the project site property line. Therefore, at a distance of 35 feet from the nearest off-site structure, groundborne vibration levels from backhoes or similar equipment used for landscaping work would attenuate to approxi-mately 0.054 PPV. At a distance of 55 feet from the nearest off-site structure, groundborne vibration levels from heavy construction equipment such as vibratory rollers or excavators would attenuate to approximately 0.064 PPV. These groundborne vibrations levels are below the industry standard vibration impact criterion of 0.20 PPV for structures of non-engineered timber and masonry construc-tion (the construction type of the adjacent buildings). In addition, these groundborne vibration levels would be not be readily perceptible to an individual in an outdoor environment at any point along or beyond the property line of the parcel containing the activity. Therefore, this construction- related groundborne vibration would not result in an exceedance of the identified standards for the cities of Cupertino and Santa Clara, and this impact would be considered less than significant. Other sensitive receptors in the vicinity of the project site include The Hamptons (multi-family residential uses) located west of the project site, in the City of Cupertino. The nearest façades are located approximately 50 feet from the nearest project site property line where construction could occur. At this distance, groundborne vibration from the operation of heavy construction equipment near the project property line would be expected to attenuate to approximately 0.074 PPV, which is well below the industry standard vibration impact criteria of 0.20 PPV for structures of non-engi-neered timber and masonry construction (the construction type of The Hamptons). Therefore, the project would not result in an exceedance of the vibration standards applicable to the City of Cupertino, and this impact would be considered less than significant.



J . N O I S E


Other sensitive receptors are the single-family residential land uses located north of the site across East Homestead Road. These properties are located in the City of Sunnyvale. The nearest façades of these residences are located approximately 150 feet from the nearest project site property line, where equipment such as backhoes could be used for landscaping construction. The closest construction activities that would require the use of heavy earthmoving construction equipment would occur at the Main Building and at the Corporate Fitness Center at distances of over 180 feet from the nearest residential units north of East Homestead Road. At a distance of 150 feet from the nearest off-site structure, groundborne vibration levels from backhoes or similar equipment used for landscaping construction would attenuate to approximately 0.006 PPV. At a distance of 180 feet, groundborne vibration levels from heavy construction equipment such as vibratory rollers or excavators would attenuate to approximately 0.011 PPV. This is well below the industry standard vibration impact criteria of 0.20 PPV for structures of non-engineered timber and masonry construction (the construc-tion type of the adjacent residential buildings). In addition, at a distance of 150 feet, these construc-tion-related groundborne vibration levels would attenuate to below levels that would be readily perceptible to an individual in an outdoor environment. Therefore, construction-related groundborne vibration would not result in an exceedance of the established standards for the cities of Cupertino and Sunnyvale, and this impact would be considered less than significant.

(4) Expose People Residing or Working in the Project Area to Excessive Noise Levels From Aircraft Noise Sources. The project site is not located within or in the vicinity of an airport land use plan or within the 55 dBA CNEL noise contour of any airport. The nearest public airports to the project site are the San Jose International Airport (5.3 miles northeast of the site), Reid-Hillview of Santa Clara County Airport (12.5 miles east of the site), and Palo Alto Airport (12.5 miles north-west of the site). The nearest private airfield, Moffett Federal Airfield, is located approximately 6.2 miles northwest of the project site. Therefore, implementation of the project would not expose persons working in the project site to excessive noise levels from aircraft noise sources. Therefore, impacts related to noise levels from aircraft noise sources would be less than significant.

(5) Create a Substantial Temporary Increase in Ambient Noise Levels. The transport of workers, construction equipment, and materials to the project site and the removal from the site of construction debris would incrementally increase noise levels on access roads leading to the site. The FHWA highway traffic noise prediction model (FHWA RD-77-108) was used to evaluate the poten-tial increase in traffic noise associated with construction traffic trips in the vicinity of the project site. The construction trip estimates were derived from the construction logistics documentation prepared for the project.8 The resultant noise levels were weighed and summed over a 24-hour period in order to determine the CNEL values. Table V.J-13 shows the traffic noise levels for existing conditions and for conditions with project construction trips added as calculated at 50 feet from the centerline of the outermost travel lanes. The model inputs and outputs, including the 60 dBA, 65 dBA, and 70 dBA noise contour distances for each modeled roadway segment are provided in Appendix E. For the purposes of this analysis, a substantial permanent increase in ambient noise levels is considered to be more than 3 dBA. As shown in the table, project construction trips would not result in an increase in traffic noise levels of more than 3 dBA along any of the modeled roadway segments in the project vicinity. (Project construction period truck traffic would result in a 3.0 dBA increase

8 Skansa and DPR, 2012. Apple Campus 2 Construction Equipment Summary. December 11.



J . N O I S E


along North Tantau Avenue between Vallco Parkway and Stevens Creek Boulevard, but no sensitive receptors are located adjacent to that roadway segment.) Therefore, short-term construction-related noise associated with worker, equipment, and materials transport to and from the project site would result in a less-than-significant temporary increase in ambient noise levels in the project vicinity. Temporary increases in ambient noise associated with excavation, grading, site preparation, and building erection on the project site are discussed under “Significant Impacts,” below. Table V.J-13: Existing and Existing Plus Construction Traffic Noise Levels at 50 feet from Centerline of Outermost Travel Lane, dBA

Roadway Segment Existing (CNEL)

Existing Plus Project

Construction Trips

(CNEL)

Change fromExisting to

Existing Plus Project

Construction Trips

Homestead Road - Sunnyvale-Saratoga Road to Blaney Avenue 66.4 67.8 1.4Homestead Road - Blaney Avenue to Wolfe Road 66.4 67.8 1.4Homestead Road - Wolfe Road to Tantau Avenue 66.5 67.8 1.3Homestead Road - Tantau Avenue to Lawrence Expressway 65.9 67.4 1.5Sunnyvale-Saratoga Road - Fremont Avenue to Homestead Road 69.3 69.3 0.0DeAnza Boulevard - Homestead Road to I-280 NB Ramps 70.2 70.2 0.0DeAnza Boulevard - I-280 SB Ramps to Stevens Creek Boulevard 69.9 69.9 0.0Wolfe Road - Fremont Avenue to Homestead Road 65.9 65.9 0.0Wolfe Road - Homestead Road to Project Entrance 67.0 68.9 1.9Wolfe Road - Project Entrance to Pruneridge Avenue 66.9 68.8 1.9Wolfe Road - Pruneridge Avenue to I-280 NB Ramps 67.8 69.4 1.6Wolfe Road - I-280 SB Ramps to Vallco Parkway 67.3 67.3 0.0Wolfe Road - Vallco Parkway to Stevens Creek Boulevard 65.9 65.9 0.0Miller Road - Stevens Creek Boulevard to Bollinger Road 64.3 64.3 0.0Tantau Avenue - Homestead Road to Pruneridge Avenue 63.2 66.1 2.9Tantau Avenue - Pruneridge Avenue to Tandem Drive 63.5 66.3 2.8Tantau Avenue - Tandem Drive to Vallco Parkway 63.8 66.4 2.6Tantau Avenue - Vallco Parkway to Stevens Creek Boulevard 63.1 66.1 3.0Lawrence Expressway - Homestead Road to Pruneridge Avenue 72.8 72.8 0.0Lawrence Expressway - Pruneridge Avenue to Stevens Creek Boulevard 72.7 72.7 0.0Stevens Creek Boulevard - SR 85 NB Ramps to Stelling Road 67.2 67.2 0.0Stevens Creek Boulevard - Stelling Road to De Anza Boulevard 66.5 66.5 0.0Stevens Creek Boulevard - De Anza Boulevard to Wolfe Road 66.1 66.1 0.0Stevens Creek Boulevard - Wolfe Road to Finch Avenue 65.3 66.8 1.5Stevens Creek Boulevard - Finch Avenue to Tantau Avenue 65.6 67.0 1.4Stevens Creek Boulevard - Tantau Avenue to I-280 SB Ramps 66.4 66.4 0.0DeAnza Boulevard - Stevens Creek Boulevard to McClellan Road 64.5 64.5 0.0DeAnza Boulevard - McClellan Road to Bollinger Boulevard 62.1 62.1 0.0

Note: Shaded cells indicate roadway segments adjacent to the project site.




J . N O I S E


c. Significant Impacts. The proposed project would result in significant project-level noise impacts as discussed below. Impact NOI-1: Project-related construction activities would create a clearly noticeable temporary change in the noise environment and create noise levels that would exceed the noise level standards in the City of Cupertino Municipal Code. (S) Two types of short-term noise impacts would occur during site preparation and project construction. The first type would result from the increase in traffic flow on local streets, associated with the trans-port of workers, equipment, and materials to and from the project site. Potential temporary increases in ambient noise levels along access roadways resulting from project construction trips were discussed under “Less-than-Significant Impacts,” above. The second type of short-term noise impact is related to the noise generated by heavy construction equipment operating on the project site. Noise generated during excavation, grading, site preparation, and building erection on the project site would result in potential noise impacts on off-site uses. Existing receptors in the vicinity, including residential land uses, would be subject to short-term noise generated by construction equipment and activities on the project site when construction occurs near the project boundary. Construction is performed in discrete steps, each of which has its own mix of equipment and, conse-quently, its own noise characteristics. These phases would change the character of the noise generated on the project site and, therefore, the noise levels surrounding the site as construction progresses. Despite the variety in the type and size of construction equipment, similarities in the dominant noise sources and patterns of operation allow construction-related noise ranges to be categorized by work phase. Table V.J-14 lists typical construction equipment noise levels recommended for noise impact assessments, based on a distance of 50 feet between the equipment and a noise receptor. Typical combined noise levels from the operation of multiple pieces of equipment range up to 91 dBA Lmax at 50 feet during the noisiest construction phases. The site preparation phase, which includes excavation and grading of the site, tends to generate the highest noise levels, because the noisiest construction equipment is earthmoving equipment. Earthmoving equipment includes excavating machinery such as backhoes, bulldozers, draglines, and front loaders. Earthmoving and compacting equipment includes compactors, scrapers, and graders. Typical operating cycles for these types of construction equipment may involve 1 or 2 minutes of full-power operation followed by 3 or 4 minutes at lower power settings. Construction of the proposed project is expected to require the use of earthmovers such as bulldozers and scrapers, loaders and graders, water trucks, and pickup trucks. The use of impact pile driving equipment or rock drills is not anticipated during construction of the proposed project. As shown in Table V.J-14, the typical maximum noise level generated by backhoes on the project site is assumed to be 86 dBA Lmax at 50 feet from the operating equipment. The maximum noise level generated by bulldozers is approximately 85 dBA Lmax at 50 feet. The maximum noise level generated by water and other trucks is approximately 86 dBA Lmax at 50 feet from these vehicles. Each doubling of the sound sources with equal strength would increase the noise level by 3 dBA. Assuming each piece of construction equipment operates at some distance apart from the other equipment, the worst-



J . N O I S E


case combined noise level during this phase of construction would be 91 dBA Lmax at a distance of 50 feet from an active construc-tion area. While the project site is located within the City of Cupertino, it is bordered by the cities of Santa Clara and Sunnyvale. According to the noise ordinances of each of these three municipalities, noise from construction activities is permitted to exceed the estab-lished maximum allowable noise perfor-mance standards, provided that the activities occur during the permissible hours for construction. In addition, for the City of Cupertino the project must implement best management noise reduction practices, including, but not limited to, meeting at least one of the following criteria: no individual device produces a noise level of more than 87 dBA Lmax as measured at a distance of 25 feet; or the operation of such equipment does not produce noise levels that exceed 80 dBA Lmax as measured at any nearby property. Table V.J-14 lists typical construction equipment noise levels recommended for noise impact assess-ments, based on a distance of 50 feet between the equipment and a noise receptor. At a distance of only 25 feet from the operating equipment noise levels would be approximately 6 dBA higher than those listed in the table. Therefore, typical maximum noise levels generated by almost all of the types of heavy construction equipment listed in the table would exceed 87 dBA Lmax at 25 feet from the operating equipment. Therefore, this analysis focuses on whether noise from multiple pieces of heavy construction equipment operating simultaneously near the project borders would result in noise levels in excess of the City’s standard of 80 dBA Lmax as measured at nearby receiving properties. Impacts to the nearest off-site sensitive land uses are discussed in detail below.

Residences East of North Tantau Avenue. The closest noise-sensitive receptors to the project site boundaries include the single-family residential land uses on Howard Drive and Meadow Avenue, whose rear property lines would be located adjacent to the proposed buildings on the east side of North Tantau Avenue. The outdoor active use areas (backyards) of these residences immedi-ately border the project site, while the nearest façades are located within 25 feet of the project site property line. A 35-foot landscaped setback is planned for project development east of North Tantau Avenue (this set back applies to proposed surface parking as well). Therefore, the closest residential façades in this area would be located approximately 60 feet from the nearest project construction activity (the outer development zone of Satellite Plant South).

Table V.J-14: Typical Construction Equipment Maximum Noise Levels, Lmax

Type of Equipment

Range of Maximum

Sound Levels (dBA at 50 feet)

Suggested Maximum

Sound Levels for Analysis

(dBA at 50 feet) Pile Drivers 81 to 96 93 Rock Drills 83 to 99 96 Jackhammers 75 to 85 82 Pneumatic Tools 78 to 88 85 Pumps 74 to 84 80 Scrapers 83 to 91 87 Haul Trucks 83 to 94 88 Cranes 79 to 86 82 Portable Generators 71 to 87 80 Rollers 75 to 82 80 Dozers 77 to 90 85 Tractors 77 to 82 80 Front-End Loaders 77 to 90 86 Hydraulic Backhoe 81 to 90 86 Hydraulic Excavators 81 to 90 86 Graders 79 to 89 86 Air Compressors 76 to 89 86 Trucks 81 to 87 86

Source: Bolt, Beranek & Newman, 1987. Noise Control for Build-ings and Manufacturing Plants.



J . N O I S E


At 60 feet and assuming a direct line of sight to heavy construction equipment operating simultane-ously in close proximity to one another, project construction activities would result in noise levels ranging up to approximately 90 dBA Lmax. However, the project would incorporate a 15-foot-high temporary sound wall along the project border adjacent to off-site noise-sensitive land uses for the duration of project construction. The sound wall would be set back 20 to 30 feet from the edge of property lines. Such a temporary sound wall system would be expected to provide an approximate 14 dBA reduction in noise levels from construction activities as measured at the nearest façade of these adjacent noise-sensitive land uses. Therefore, with the installation of a minimum 15-foot-high temporary sound barrier, construction noise levels would be reduced to approximately 76 dBA Lmax, as measured at the nearest façades of these adjacent residential land uses. This construction period project feature would reduce construction noise levels, as measured at the nearest façade of noise sensitive land uses, to below the City’s threshold of 80 dBA Lmax, with an adequate margin of safety.

Apartments South of Pruneridge Avenue. Other noise-sensitive receptors in the vicinity of the project site include The Hamptons (multi-family residential uses) located west of the project site. The nearest private outdoor active use space (balcony) of these residences is located approximately 50 feet from the project site property line, while the nearest façades are also located approximately 50 feet from the nearest project site property line. The closest common use outdoor active use area (the pool area) of this multi-family residential land use is located approximately 325 feet from the nearest project site property line. Therefore, if multiple pieces of heavy construction equipment are operated simultaneously near this project border, noise levels could range up to 91 dBA Lmax at the nearest residential façade and could range up to approximately 75 dBA Lmax at the nearest outdoor active use area. However, as noted previously, the project would incorporate a 15-foot-high temporary sound wall along the project border adjacent to off-site noise-sensitive land uses for the duration of project construction. Such a temporary sound wall system would be expected to provide an approximate 15 dBA reduction in noise levels from construction activities that would occur near the project border as measured at the nearest façade of apartments located south of Pruneridge Avenue. Therefore, with the installation of a minimum 15-foot-high temporary sound barrier, construction noise levels would be reduced to approximately 76 dBA Lmax, as measured at the nearest façades of these adjacent residen-tial land uses. This would reduce construction noise levels to below the City’s threshold of 80 dBA Lmax, with an adequate margin of safety.

Residences North of East Homestead Road. Other close noise-sensitive land uses to the project site are the single-family residential land uses located north of the project site across East Homestead Road. The nearest façades of these residences are located approximately 150 feet from the nearest project site property line. At this location, the project would include a minimum 30-foot setback for all project construction, including sound walls. Therefore, operation of heavy equipment during project construction could occur within approximately 180 feet of these residential units. If multiple pieces of heavy construction equipment operate simultaneously near the project’s northern border, noise levels could range up to 80 dBA Lmax at the nearest residential façade. However, as noted above, the project would also incorporate a 15-foot-high temporary sound wall along the entire project border adjacent to off-site noise-sensitive land uses for the duration of project construction. The sound wall would be set back 30 feet from the edge of the property line. Such a temporary sound wall system would be expected to provide an approximate 14 dBA reduction in



J . N O I S E


noise levels from construction activities as measured at the nearest façade of these adjacent noise- sensitive land uses. Therefore, with the installation of a minimum 15-foot-high temporary sound barrier, construction noise levels would be reduced to approximately 77 dBA Lmax, as measured at the nearest façades of these adjacent residential land uses. This construction period project feature would reduce construction noise levels, as measured at the nearest façade of noise sensitive land uses, to below the City’s threshold of 80 dBA Lmax, with an adequate margin of safety. All construction work would conform to the requirements of Chapter 10.48 (Community Noise Control) of the Municipal Code. In addition, no helicopters would be used during construction. In addition to the construction of temporary sound walls around the project site during construction of the proposed project, Apple plans to incorporate industry standard best management practices to further reduce impacts from construction-related noise. To ensure implementation and to permit monitoring of these proposed project design features and of the best management practices so that project-related construction noise impacts are reduced to a less-than-significant level, the following multi-part mitigation measure shall be implemented:

Mitigation Measure NOI-1: The project applicant shall implement the following measures at the project site during all demolition and construction activities, subject to the approval of the City:

The project applicant shall ensure the construction of a 15-foot high temporary sound wall along the project’s property line adjacent to sensitive land uses.

○ A temporary sound wall shall be constructed along the eastern project property line to block the line-of-sight from the single-family residential land uses on Howard Drive and Meadow Avenue to project construction areas on the east side of North Tantau Avenue. This sound wall shall be set back from the property line as much as feasible to still allow for project construction activities to occur.

○ A temporary sound wall shall be constructed along the southern project property line to block the line-of-sight from The Hamptons to project construction areas in the south-west portion of the project site. This sound wall shall be set back from the property line as much as feasible to still allow for project construction activities to occur.

○ A temporary sound wall shall be constructed along the northern project property line to block the line-of-sight from the single-family residential properties north of East Homestead Road to project construction areas in the northern portion of the project site. This sound wall shall be set back from the property line as much as feasible to still allow for project construction activities to occur.

The project contractor shall designate a construction liaison that shall be responsible for responding to any local complaints about construction noise. The liaison shall determine the cause of the noise complaints (e.g., starting too early, bad muffler) and institute reasonable measures to correct the problem. A telephone number for the liaison shall be conspicuously posted at the perimeter of the construction site and provided to all adjacent property owners prior to commencement of construction.

The project contractor shall ensure that all construction equipment has appropriate high-quality noise muffling and abatement devices, which would be properly maintained and used at all times such equipment is in operation.



J . N O I S E


The project contractor shall, to the extent feasible, place all stationary construction equip-ment so that emitted noise is directed away from sensitive receptors nearest the project site.

Exterior project noise-generating construction activities (i.e., grading, construction and demolition) shall be permitted within 750 feet of any residentially zoned property only between the hours of 7:00 a.m. and 8:00 p.m. on weekdays, and between the hours of 9:00 a.m. and 6:00 p.m. on weekends. No such work shall be permitted on holidays (i.e., New Year’s Day, Memorial Day, Independence Day, Labor Day, Thanksgiving Day, Christmas Day), except as approved by the Community Development Director. A Noise Variance may be obtained from the Noise Control Officer for each occurrence of specific temporary construction activities.

Construction activities, other than street construction, shall be prohibited on holidays, unless they meet the City of Cupertino’s nighttime maximum permissible noise level standards. (LTS)

With implementation of the project’s proposed temporary sound wall system and the best manage-ment practices listed above, noise from project-related construction activities would be reduced to a less-than-significant level. d. Cumulative Impacts. The only cumulatively considerable contribution of the project to noise conditions would result from project-related increases in traffic noise levels along some roadway segments in the project site vicinity. Impact NOI-2: Implementation of the project would result in a significant contribution to cumulative traffic noise levels experienced in the project vicinity. (S) For the purposes of the project-level roadway noise analysis described above, only audible changes in the outdoor noise environment (3.0 dBA or greater) are considered potentially significant. However, in evaluating whether the project would make a significant contribution to a cumulative roadway noise impact (i.e., an impact associated with noise generated by past, present, and reasonably foreseeable future projects) a more stringent threshold of 1.0 dBA is used. A noise increase of 1.0 dBA represents the lowest range of a potentially audible noise increase in a laboratory environment. This more stringent threshold is used in the evaluation of the project’s incremental contribution to cumulative noise impacts in recognition that many small changes in the noise environment, taken together, can create an unacceptable noise level. This cumulative impact analysis employs a two-step analysis. First, the roadway segments in the vicinity of the site were analyzed to determine which segments, under cumulative plus project conditions, would have noise levels that exceed the normally acceptable threshold for the most-sensitive adjacent land uses. Second, for roadway segments that would exceed the normally acceptable threshold, the project’s contribution to cumulative noise levels was identified. If the project would contribute 1.0 dBA or more to a roadway segment that in cumulative plus project conditions would exceed normally acceptable noise levels, the project would make a significant contribution to the cumulative impact.



J . N O I S E


As shown in Table V.J-12 and on Figure V.J-3, cumulative plus project traffic noise levels on several modeled roadway segments would exceed the City’s normally acceptable thresholds for the identified adjacent land uses. However, only two roadway segments would experience increases of 1.0 dBA or greater in traffic noise levels under cumulative plus project conditions and would exceed the normally acceptable noise threshold for adjacent land uses. These two roadway segments are: 1) East Home-stead Road, from North Wolfe Road to North Tantau Avenue and 2) North Wolfe Road, from Pruneridge Avenue to the I-280 northbound ramps. Therefore, the project would make a significant contribution to cumulative roadway noise impacts at these two roadway segments. Construction of sound walls along these two roadway segments would not be feasible due to property access requirements and conflicts with the City’s General Plan (which discourages permanent sound walls). However, resurfacing the roadway segments that would experience cumulative traffic noise impacts with Rubberized Hot Mix Asphalt-Open Graded (RHMA-O) or similar quieter pavement would reduce the project’s contribution to cumulative noise levels to a less-than-significant level. This type of pavement has been shown in various studies to result in a 4 to 6 dBA reduction in noise levels, with an average 4 dBA reduction in traffic noise realized in a long-term study in California.9 While using RHMA-O or similar quiet pavement to resurface the affected roadway segments would not reduce traffic noise levels to below the City’s normally acceptable thresholds for the adjacent single-family residential and multi-family residential land uses (60 dBA and 65 dBA CNEL respec-tively), it would eliminate the project’s contribution to the cumulative impact. For example, cumu-lative plus project traffic noise levels along East Homestead Road from North Wolfe Road to North Tantau Avenue of 67.9 dBA CNEL would be reduced to below 63.9 dBA CNEL after resurfacing with RHMA-O or a similar quiet pavement. This reduced noise level would be below the cumulative traffic noise level of 66.9 dBA CNEL that would be experienced along this roadway segment under conditions without the project. It would also be below the existing traffic noise level of 66.5 dBA CNEL. Therefore, with implementation of the following measure the project’s contribution to the cumulative impact would be reduced to a less-than-significant level.

Mitigation Measure NOI-2: The project sponsor shall resurface the following roadway segments with RHMA-O or similar quiet pavement:

East Homestead Road, from North Wolfe Road to North Tantau Avenue; and

North Wolfe Road, from Pruneridge Avenue to the I-280 northbound ramps. (LTS)

9 Sacramento County, 1999. Department of Environmental Review and Assessment, Report of the Status of

Rubberized Asphalt Traffic Noise Reduction in Sacramento County. November.

Documents

J. NOISE 1. - Amazon S3...frequency response of the human ear and correlates well with subjective reactions to noise. All sound levels in this section are A-weighted, unless reported