CC 06-18-19 #20 Public Storage 20565 Valley Green Dr _Written Communications6/13/19
Mayor & Council Members
City of Cupertino
10300 Torre Avenue
Cupertino, CA 95014
BERG & BERG DEVELOPERS, INC.
10050 Ba11dley Drive
Cupertino, CA 95014-2188
Ph (408) 725-0700 Fax 408-703-2035
mcrawford@bergvc.com
Ph 408-777-3308 3251 Fax 408-777-3333
sscharf@cuperti no . org ; l iangchao@cuperti no. org; rsi nks@cuperti no . org ; dpaul@cuperti no. org;
jwi lley@cuperti no. org ;
cityclerk@cuperti no . org
Dear Mayor & Council Members,
Reference: Public Storage CC 6-18-19 Item #20
Subject: Comments and Suggestions
cc 6/18/19
Item #20
Public Storage has done considerable outreach and has attempted to anticipant the
impacts of their project. However, since their project will impact the neighboring
properties and tenants we feel the following should be considered as a part of the
approval process and conditions, Public Storage should be required to do:
1. Have and share a proposed Construction Management Plan with surrounding
property owners and tenants prior to submittal to the city for approval. At a
minimum, the Construction Management Plan should include the following:
-Construction schedule ( demolition, grading, construction)
-Hours of construction
-Location of construction staging and parking
-24-hr contact information (name/telephone number) for inquiries and
complaints during construction
-To the extent reasonably practical, schedule Public Storage related inbound
and outbound construction traffic to minimize the impact on the limited access
road from Valley Green Drive and existing users of that access road
-Re-occupancy Move in -Develop a plan to orderly re-occupy the existing
Public Storage tenants to minimize traffic and parking impacts
2. Provide a minimum two weeks advance notice to surrounding property owners
and tenants prior to the start of any construction activity.
3. Maintain all shared access ways/drive aisles clear of any construction debris
and equipment. Recondition the existing access roadway from Valley Green Drive
for any wear and tear related to the Public Storage construction at the end of the
project.
ll P age
4. Post the 24-hr contact information (name/telephone number) at the west and
east ends of the site for inquiries and complaints during construction.
5. Ensure all Public Storage-related parking (during construction and post-
construction) is contained entirely on the project site.
Some of these concerns may have been previously addressed or planned for but in the
interest of caution we are providing comment to insure all concerns are addressed to
the extent possible.
Thank you for your consideration,
Myron Crawford
2[Page
Cyrah Caburian
From:
Sent:
To:
Subject:
Attach men ts:
Kitty Moore
Friday, June 14, 2019 1:06 PM
Steven Scharf; Liang Chao; Rod Sinks; Darcy Paul; Jon Robert Willey
Public Storage I 280 Noise Air Pollution
Air Quality and Noise Potentials along I-280.pdf
Hi Mayor Scharf, Vice Mayor Chao, and Council Members Sinks, Paul, and Willey,
cc 6/18/19
Item #20
The Public Storage project will be coming to the CCC. As you are aware, planned developments do not have setback standards.
The Public Storage project increased the setback on the south side from around 55' to over 150' and has a small, park-like area
outside of the gates. This provides an .increased buffer between the townhouses.
The setback on the 1-1280 side (north} has been increased and the existing chain link fence will be moved in 12' to accommodate
the proposed bike path and provides some design flexibility.
There is a single apartment in the proposed project. It is on the most northwest corner, ground floor, facing the 1-280. Having
studied the Valko El Rs, it would seem there would be similar air quality and noise conditions at this location as was found for
the Valko area. I have included a PDF with pertinent excerpts from the Valko EIR showing the PM 2.5 concentrations and noise
contours. I have also included the GP Future Noise Contours map and Land Use Compatibility Figure HS-8. Also find pages of
mitigations from the Valko EIR.
I suggested they install air filtration and perhaps triple pane windows in that one unit due the the proximity to the freeway.
The suggested system for air filtration is MERV-13 or higher, in the Valko EIR. Additionally, sound-rated windows and doors are
suggested in order to keep the indoor noise levels at the acceptable threshold, 45 dBA. I would like to see these mitigation
items implemented in the plans.
Thank you,
1
Ill DAVID J. POWERS
B@~ & ASSOCIATES . INC .
May 20 18
413~00
~ ..
[
14 131'600 .
413 12()0)
41 W JOO
I
$00800
Source: Illingworth & Rodkin, Inc., April 6, 2018.
PM2.5 Conc,e:ntration Contours for
In erst ate !?80 n affi t
I
5&7 200 SIJ14QO
PROJECT SITE PM2.5 CONCENTRATIONS (µg/m3) FROM 1-280
76
N
J\
FIGURE 3.3-1
Future Noise Contours
hllt~mJ~1
<=55
55<.<=60
<=65
<=70
<= 75
<=80
<=85 -85 <
Main building
Source: llllngv.ooh & Rodkin , Inc.
FUTURE NOISE CONTOURS FOR CUMULATIVE PLUS PROJECT/PROJECT ALTERNATIVE SCENARIOS FIGURE 3.13-2
COMMUNITY V I SION 2040
C i t y of C u per ti no
Figure D-2
Future Noise Contours
CV,
D-H
Santo Clara
Co unty
0.25 O.S
City af San Jase
' \ .. i ' ..-:-r PR05P ECT RD \
City a
Senta Clara
..
.. (
-60 dBA CNEL co ntour
-65 dBA CNEL contour
-70 dBA CNEL contou r
City Boundary
CHAPTER7:HEALTHANDSAFETYELEMENT I CJ'=li:rc! pl;;: <,:,:,n •1r.un1t y v1s1c11 2:)15 -211"-l',
Land Use Category Community Noise Exposure
(Lein or CNEL, dB)
55 60 65 70 75
Residential Low Density
(Single Family, Duplex,
Mobile Homes)
Residential -Multi Family
Transient Lodging
(Motels, Hotels)
Schools, Libraries, Churches,
Hospital s, Nursing Homes
Auditoriums, Concert Halls,
Amphitheaters
Sports Arena, Outdoor
I
Spectator Sports
Playgrounds, •=-
Neighborhood Parks I
Golf Courses, Riding Stables,
Water Recreation, Cemeteries
Office Buildings, Commercial I
and Professional Centers
Industrial, Manufacturing,
Utilities, Agriculture I ·
Representative Sounds and Sound Levels
___J~Q__ Permanent Hearing Damage
Il l ____]311_ 1 Community
(Outdoor) Il l r Threshold of Pain
___J,f ,11_ ,
Amphitheater rock music (100') ___J 111_ Riveting machine -Il l
Ambulan ce siren (100') ___JI0IIIL_ Coal4ired power plant
Motorcycle (25') 90 Booiler room
Locomotive (50') -Il l-Food blender
'
-m-
_JO_
Rail cars (100') Ill Aitfine passenger compartment
Vacuum deane r (31
Large air conditioning unit (100') 60 -,,-
Large transformer (200') ___,5111-• 40 Open plan business office
-11,-Privateoffice
Data processing center
Insects _3IIOI_ Quiet bedroom at night
__20_
Mosquito (3') \!
80
--
-
I
I .,
Home or
lndust,y
(Indoor)
-"Weighted Sound Pressure Level,
irl dtcibels(dB}
-,.,-
-,-lmeshofdofHearing ______ __.
Normally Acceptable
Specified la nd use is satisfactory,
based upon the assumption that any
buildings involved are of normal
conventional construction, without
any special noise i nsulation
re qu irements.
c:==J
Conditionally Acceptable
New construction or development
should be undertaken only after a
detailed anal ysis of the noise
reduction requirements is made and
needed noise reduction features
included in the design. Conventional
construction, but with closed windows
and fresh air supply systems or air
conditioning will normally suffice .
Normally Unacce ptable
New construction or development
should generally be discouraged. If
new construction or development
does proceed, a det ai led analysis of
the noise reduction requirements
must be made and needed noise
insulation features included in the
design. -Clearly Unacceptable
New construction or development
shou ld generally not be undertaken.
Mitigation Measure:
MMAQ-7.1: Future development under the proposed project (and General Plan Buildout with
Maximum Residential Alternative and Retail and Residential Alternative) shall
implement mitigation measure MM AQ-2.1 to reduce on-site diesel exhaust
emissions; which would thereby reduce the maximum cancer risk due to
construction of the project (~d General Plan Buildout with Maximum
Residential Alternative and Retail and Residential Alternative).
With the implementation ofthe above mitigation measure, the maximum cancer risk from the project
construction (and General Plan Buildout with Maximum Residential Alternative, and Retail and
Residential Alternative) would be 4.4 in one million or less, which is below th~ BAAQMD threshold
of greater than 10 per one million for cancer risk. (Less than Significant with Mitigation
Incorporated) '
General Plan Buildout with Maximum Residential Alternative
The construction of the General Plan Buildout with Maximum Residential Alternative would result in
the similar health risk exposure to sensitive receptors as described above for the proposed project.
See Impact AQ-7 and mitigation measure MM AQ-7 .1. (Less than Significant with Mitigation
Incorporated)
Retail and Residential Alternative
The construction of the Retail and Residential Alternative would result in the similar health risk
exposure to sensitive receptors as described above for the proposed project. See Impact AQ-7 and
mitigation measure MM AQ-7 .1. (Less than Significant with Mitigation Incorporated)
Occupied/Re-Tenanted Mall Alternative ·
The Occupied/Re-Tenanted Mall Alt~rnative would result in construction emissions related to
exterior and interior tenant improvements. It is anticipated that the construction emissions under this
alternative would be much lower than those involved with demolition, grading, and new exterior
building construction, which would occur under the proposed project, General Plan Buildout with
Maximum Residential Alternative, and Retail and Residential Aiternative. In addition, interior work
typically involves minimal diesel equipment and would be completed indoors. For these reasons, it
is anticipated the construction-related health risk from this alternative would be less than significant.
(Less than Significant Impact: Not a CEQA Impact)
Exposure of On-Site Sensitive Receptors to Toxic Air .Contaminants -Planning Consideration
Project
As previously discussed in Section 3 .0, in 2015 the California Supreme Court ruled that CEQA does
not generally require an analysis of the impacts oflocating development in areas subject to
environmental hazards unless the project would exacerbate those existing environmental hazards or
Vallco Special Area Specific Plan
City of Cupertino
72 Draft Environmental Impact Report
May 2018
the hazards at issue are subject to certain specified exceptions to this general rule. 21 The City of
Cupertino has policies, however, that address existing air quality conditions affecting a proposed
project. Determining whether new on-site receptors would be affected are the same as those listed
for Project Health Risk and Cumulative Health Risk in Table 3 .3-2, above.
The proposed project (and General Plan Buildout with Maximum Residential Alternative, and Retail
and Residential Alternative) would include the development of new sensitive receptors, such as new
residents, in locations near existing roadways and highways. Future on-site sensitive receptors,
therefore, would be exposed to levels ofTACs and/or PM2.s from adjacent roadways and highways
that could cause an unacceptable cancer risk or hazard. Existing stationary sources are also a source
ofTACs, however, a search of the BAAQMD screening tool did not reveal any stationary sources
that would have an impact on the project site.
Increased cancer risks and exposure to PM2.s were calculated consistent with BAAQMD and CARB
recommended risk assessment methods. In general, cancer risks will decrease with distance from the
roadway and with height of the receptors (i.e., residents on upper floors). The impact of these
roadways on the proposed project are discussed further below. Refer to Appendix B for modeling
details, data inputs, and assumptions.
• Interstate 280 -The predicted maximum increased cancer risk at the project site from traffic
on I-280 was calculated to be 4.0 in one million, which is below than the BJ\AQMD
threshold of significance of 10 in one million. Impacts from PM2.s emissions from I-280
would occur at the project site along portions of the site closest to the freeway. BAAQMD
adopted a significance threshold of an annual average Pl\12.s concentration greater than 0 .3
µg/m 3 • Appendix B shows contour lines on the site where PM2.s concentrations would occur
at or above the BAAQMD threshold of significance of 0.3 µg/m 3 . For distances within about
530 feet from I-280 on the project site west of North Wolfe Road and within about 620 feet
from I-280 on the project site east of North W0lfe Road, PM2.s concentrations would be
significant. The Hazard Index (HI) is estimated to be 0.0006, which is below the BAAQMD
threshold of significance of 1.0.
• Stevens Creek Boulevard -The predicted maximum increased cancer risk at the project site
from traffic on Stevens Creek Boulevard was calculated to be 2.2 in one million, which is
below the BAAQMD threshold of significance of 10 in one million. Figure 3 .3-2 shows the
contour lines on the project site where PM2.s concentrations would occur at or above the
BAAQMD threshold of significance of 0.3 µg/m 3 • For distances within about 130 feet from
Stevens Creek Boulevard at the project site, PM2.s concentrations would be significant. The
HI is estimated to be 0.0004, which is below the BAAQMD threshold of significance of 1.0.
• North Wolfe Road-The predicted maximum increased cancer risk at the project site from
traffic on North Wolfe Road was calculated to be 3.3 in one million, which is below the
BAAQMD threshold of significance of 10 in one million. Figure 3.3-3 shows the contour
lines on the project site where PM2.s concentrations would occur at or above the BAAQMD
threshold of significance of 0.3 µg/m 3• For distances within about 95 feet :from North Wolfe
Road and within about 215 feet east ofNorth Wolfe Road, PM2.s concentrations would be
21 California Building Industry Association v. BAAQMD, 62 Cal. 4th 369, filed December 17, 2015.
Valko Special Area Specific Plan
City of Cupertino
73 Draft Environmental Impact Report
May2018
significant. The HI is estimated to be 0;0006, which is below the BAAQMD threshold of
significance of 1.0.
• Vallco Parkway-The predicted maximum increased cancer risk at the project site from
traffic on North Wolfe Road was calculated to be 8.6 in one million, which is below the
BAAQMD threshold of significance of 10 in one million. The PM2.s concentrations and HI
on-site from traffic on Vallco Parkway are estimated to be 0.25 µg/m 3 and 0.03, which are
below their respective BAAQMD thresholds of significance of 0.3 µg/m 3 and 1.0.
Figure 3.3-4 shows the cot:~_bined annual PM2.s concentrations across the project site for all three
roadways (I-280, Stevens Creek Boulevard, .and North Wolfe Road). Areas with potentially
significant annual PM2.s concentrations are highlighted, Excess cancer risk from these combined
sources were found to be below the BAAQMD 100 in one million combined source significance
threshold. Non-cancer health effects from these combined sources would not exceed the significance
threshold of a HI of greater than 10.0. Refer to Appendix B for modeling details, data inputs, and
assumptions.
The proposed project (and General Plan Buildout with Maximum Residential Alternative, and Retail
and Resi4ential Alternative) could also allow development of new non-residential land uses that are
potential emissions sources. The proposed project (and General Plan Buildout with Maximum
Residential Alternative, and Retail and Residential Alternative) could include stationary sources of
pollutants that would be required to obtain permits to operate in compliance with BAAQMD rules.
These sources include, but are not limited to, dry cleaners and back up diesel generators. The permit
process ensures that these sources would be equipped with the required emission controls and that,
individually, these sources would result in a less than significant community risk impact.
The project would include a transit hub. It is estimate_d that 15 buses would service the transit hub
daily. Assuming the buses would be diesel powered, this relatively small number of daily buses
accessing the transit hub would not be expect_ed to pose a significant community tisk impact to future
residents on-site.
The proposed project (and General Plan Buildout with Maximum Residential Alternative and Retail
and Residential Alternative) would allow new residential land uses on-site that would be exposed to
TAC and PM2.s concentrations above the BAAQMD threshold of significance.
Consistent with City of Cupertino General Plan policies, the Specific Plan includes design policies
that require the following to reduce TAC and PM2.sexposure where sensitive receptors are located
within the setback distances identified above and shown in Figure 3.3-1, Figure 3.3-2, and Figure
3.3-3:
• Future development under the proposed project (and General Plan Buildout with Maximum
Residential Alternative and Retail and Residential Alternative) that includes sensitive
receptors (such as residences or daycare centers) located within the above discussed setback
distances from 1-280 and local roadways shall require site-specific analysis to quantify the
level of TAC and PM2.s exposure. This analysis shall be conducted following procedures
outlined by BAAQMD. If the site-specific analysis reveals significant exposur~s, such as
cancer risk greater than 10 in one million acute or chronic hazards with a HI greater than 1.0,
Vallco Special Area Specific Plan
City of Cupertino
74 Draft Environmental Impact Report
May2018
or annual PM2.s exposures greater than 0.3 µglm3, or a significant cumulative health risk in
terms of excess cancer risk greater than 100 in one million, acute or chronic hazards with a
HI greater than 10.0, or annual PM2.s exposures greater than 0.8 µg/m3, additional measures
such as those detailed below shall be implemented to reduce the risk to below the threshold.
If this is not possible, the sensitive receptors shall be relocated.
-For significant cancer risk exposure, as defined by BAAQMD, indoor air filtration
systems shall be installed to effectively reduce particulate levels to below the
significance threshold. Project sponsors shall submit performance specifications and
design details to demonstrate that lifetime residential exposures would result in less
than significant cancer risks (less than 10 in one million chances or 100 in one
million for cumulative sources), HI, and PM2.s concentration, To reduce significant
9ommunity health risk exposure, future development shall implement the following
measures:
• Air filtration systems installed at significantly impacted sensitive receptor
buildings shall berated MERV-13 or higher and a maintenance plan for the
air filtration system shall be implemented.
• Trees and/or vegetation shall be planted between sensitive receptors and
pollution sources, if feasible. Trees that are best suited to trapping particulate
matter shall be planted, including the following: pine (Pinus nigra var.
maritime), cypress (X Cupressocyparis leylandii), hybrid poplar (Populus
deltoids X trichocarpa), and redwoods (Sequoia sempervirens).
• Sites shall be designed to locate sensitive receptors as far as possible from
any freeways, roadways, diesel generators, and distribution centers.
■ Operable windows, balconies, arid building air intakes shall be located as far
away from TAC sources as feasible. If future residences are located near a
distribution center, residences shall not be located immediately adjacent to a
loading dock or where trucks concentrate to deliver goods. ·
• Future development under the proposed project ( and General Plan Build out with Maximum
Residential Alternative and Retail and Residential Alternative) that would include TAC
sources (such as diesel backup generators) would be evaluated through the CEQA
environmental review process or BAAQMD permit process to ensure they do not cause a
significant health risk in terms of excess cancer risk greater than 10 in one million, acute or
chronic hazards with a HI greater than 1.0, or annual PM2.s exposures greater than 0.3 µg/m 3,
or a significant cumulative health risk in terms of excess cancer risk greater than 100 in one
million, acute or chronic hazards with a HI greater than 10.0, or annual PM2.s exposures
greater than 0.8 µg/m 3 .
Vallco Special Area Specific Plan
City of Cupertino
75 Draft Environmental Impact Report
May 2018
Table 3.13-5: Cumulative Plus Project Setback Distances to Meet the 70 dBA CNEL
Threshold of Common Outdoor Use Areas at Commercial Land Uses
Roadway Distance from Centerline to 70 dBA CNEL
(feet)
I-280 580
Perimeter Road, north of Stevens Creek Boulevard 30
Perimeter Road, near Amherst Drive <15
Perimeter Road, west of North Wolfe Road .55
Perimeter Road, east of North Wolfe Road 200
Perimeter Road, north of Vall co Parkway 35
Stevens Creek Boulevard 85
Vallco Parkway 60
North Wolfe Road, north of Stevens Creek 115 Boulevard
North Wolfe Road, at Vallco Parkway 115
North Wolfe Road, south of Perimeter Road 125
North Wolfe Road, north of Perimeter Road 150
Future Interior Noise Environment
The state of California requires that interior noise levels be maintained at 45 dB A CNEL or less at
multi-family residences and lodging facilities where occupants sleep, and the CALGreen Code
requires that interior noise levels in offices and commercial buildings be maintained at or below at 50
dBA Leq(l-hr) or less during hours of operation.
The state of California requires that interior noise levels for residential land uses be at or below 45
dBA CNEL. For commercial land uses, the 2016 Cal Green Code would apply, which requires·
interior noise levels be maintained at 50 dBA Leq(l-hr) or less during hours of operation, which are
assumed to be daytime hours of7:00 AM to 10:00 PM for the proposed commercial uses.
• Proposed Multi-Family Residential Land Uses -Standard residential construction provides
approximately 15 dBA of exterior-to-interior noise reduction, assuming the windows are
partially open for ventilation. With the windows closed, standard construction provides
approximately 20 to 25 dBA of noise reduction in interior ·spaces. Where exterior noise
levels range from 60 to 65 dBA CNEL, the inclusion of adequate forced-air mechanical
ventilation is often the method selected to reduce interior noise levels to acceptable levels by
allowing the resident to close the windows to control noise. Where noise levels exceed 65
dBA CNEL, forced-air mechanical ventilation.systems and sound-rated construction methods
are normally required. Such methods or materials may include a combination of smaller
window and door sizes as a percentage of the total building fac;ade facing the noise source, ·
sound-rated windows and doors, sound-rated exterior wall assemblies, and mechanical
ventilation so windows may be kept closed at the occupant's discretion.
Vallee Special Area Specific Plan
City of Cupertino
212 Draft Environmental Impact Report
May2018
For residential buildings proposed under the project, General Plan Bt1:ildout with Maximum
Residential Alternative and Retail and Residential Alternative set back from the nearby
roadway centerline at the distances shown in Table 3.13-4, the exterior:..facing units would be
exposed to future exterior noise levels of 65 dB A CNEL and the future interior noise levels at
these units would be 50 dBA CNEL, which would exceed 45 dBA CNEL Proposed
residential buildings set back from the nearby roadway centerline equivalent to the distances
shown in Table 3 .13-4 that are built with standard construction materials would not meet the
City's interior noise level threshold and would require noise insulation features to be
compatible with the noise environment at the site (see standard permit conditions identified
below).
• Proposed Commercial/Office Land Uses -Hourly average noise levels during business hours
within proposed ( or reoccupied) commercial land uses would need to meet the 50 dBA Leq(l-
hr) threshold established by the 2016 Cal Green Code. Standard commercial construction
materials would provide at least 20 to 25 dBA of noise reduction in interior spaces. The
inclusion of adequate forced-air mechanical ventilation systems is normally required so
windows may be kept closed at the occupants' discretion.
Assuming a minimum of 20 dB A of exterior-to-interior noise reduction, the future interior
noise levels would be 50 dBA Leq(l-hr) or less at the setback distances shown in Table 3.13-5.
Commercial/office buildings proposed nearer to roadways than the minimum distances
shown in Table 3.13-5 would potentially be exposed to interior noise levels above 50 dBA
Leq(l-hr) and.would require noise insulation features to be compatible with the noise
environment at the site (see standard permit conditions identified_below).
Standard Permit Conditions: Future development under the proposed project, General Plan
Buildout with Maximum Residential Alternative, or Retail and Residential Alternative shall
implement the following standard permit conditions to comply with required exterior and interior
noise levels standards:
• An acoustical study shall be completed during the application process when project-specific
information, such as building elevations, layouts, floor plans, and position of buildings on the
site, is known. The study shall determine compliance with the noise and land use
compatibility standards, identify potential noise impacts, and propose site-specific measures
to reduce exposure to exterior and interior noise levels that exceed maximum permissible
levels.
• To reduce exterior noise levels to meet the normally acceptable thresholds of 65 dBA CNEL
at multi-family residences or 70 dBA CNEL at commercial uses, locate noise-sensitive
outdoor use areas away from major roadways or other significant sources of noise when
developing site plans. Shield noise-sensitive spaces with buildings or noise barriers to reduce
exterior noise levels. The final detailed design of the heights and limits of proposed noise
barriers shall be completed at the time that the final site and grading plans are submitted.
• The following shall be implemented to reduce interior noise levels to meet the normally
acceptable thresholds of 45 dBA CNEL at multi-family residences or 50 dBA Leq(l-hr) at
commercial uses during hours of operations:
Vallco Special Area Specific Plan
City of Cupertino
213 Draft Environmental Impact Report
May 2018
If future exterior noise levels at residential building facades are between 60 and 65
dBA CNEL, incorporate adequate forced-air mechanical ventilation to reduce interior
noise levels to acceptable levels by closing the windows to control noise.
If future exterior noise levels at residential building facades exceed 65 dBA CNEL,
forced-air mechanical ventilation systems and sound-rated construction methods are
normally required. · Such methods or materials may include a combination of smaller
window and door sizes as a percentage of the total building fac;ade facing the noise
source, sound-rated windows and doors, sound-rated exterior wall assemblies, and
mechanical ventilation so windows may be kept closed at the occupant's discretion:
If the 50 dBA Leq(l-hr) threshold would not be met, other site-specific measures, such·
as increasing setbacks of the buildings from the adjacent roadways, using shielding
by other buildings or noise barriers to reduce noise levels, implementing additional
sound treatments to the building design, etc. shall be considered to reduce interior
noise levels to meet the Cal Green Code threshold.
The project and project alternatives would result in the same or similar future exterior and interior
noise environment as described above. Inclusion of the above-described standard permit conditions
would ensure future residential and commercial uses of the proposed project (or General Plan
Buildout with Maximum Residential Alternative or Retail and Residential Alternative) conform to
applicable exterior and interior noise standards. The Occupied/Re-Tenanted Mall Alternative is a
permitted land use, and can be implemented without further discretionary approvals from the City or
environmental review under CEQA. No mitigation measures or additional conditions of approval
can be required.
Construction Noise
Project
It is assumed that the proposed project (and General Plan Buildout with Maximum Residential
Alternative and Retail and Residential Alternative) would limit construction activity to daytime
hours, Monday through Friday, consistent with Section 10.48.053 of the Municipal Code.
Construction activities generate considerable amounts of noise, especially during demolition, earth-
moving, and infrastructure construction phases when heavy equipment is used. The highest
maximum noise levels generated by construction of the project (or General Plan Buildout with
Maximum Residential Alternative or Retail and Residential Alternative) would typically range from
about 80 to 90 dBA Lmax at a distance of 50 feet from the noise source. Typical hourly average
construction-generated noise levels for residential mixed-use buildings are about 81 to 88 dBA Leq
measured at a distance of 50 feet from the center of the site during busy construction periods ( e.g.,
earth moving equipment, impact tools, etc.). Hourly average construction noise levels for hotels and
office buildings typically range from 78 to 89 dBA Leq-86 Construction-generated noise levels drop
off at a rate of about six dB A per doubling of the distance between the source and receptor.
Shielding by buildings or terrain can provide an additional five to IO dB A noise reduction at distant
receptors.
86 Typical hourly average construction-generating noise levels include noise generated from removal of trees.
Vallee Special Area Specific Plan
City of Cupertino
214 Draft Environmental Impact Report
May 2018
A, detailed list of equipment expected for project ( and General Plan Buildout with Maximum
Residential Alternative and Retail and Residential Alternative) construction_ and construction phasing
information were not available at the time of the noise study. Appendix F provides detailed
information regarding the maximum noise levels generated by various pieces of construction
equipment, as well as typical noise levels ranges for construction phases of a variety of development
types. Several individual pieces of equipment would potentially produce noise levels that would
exceed the City's 87 dBA Lnax limit at25 feet; the noisiest of which would be impact pile driving.
hnpact pile driving-would result in maximum noise levels up to 105 dBA Lnax at 50 feet, which
would equate to 111 dBA Lnax at 25 feet. This would be a potentially significant impact.
Without knowing the_ location on the site for each proposed land use, distances to the shared property
lines of the adjacent residential land uses cannot be. determined, and exact construction noise levels
cannot be estimated. Based upon typical construction noise ievels for various land uses, minimum
distances from the residential property lines to the center of the construction sites for each proposed
land use type were calculated to meet the 80 dBA Leq threshold at the nearby residence property line.
Table 3.13-6 summarizes the minimum distances required to meet the City's threshold.
Table 3.13-6: Minimum Distances from Nearby Existing Residential Property Lines to the·
Center of the Construction Site Required to Meet the 80 dBA Le4 Threshold
Type of Proposed Land Use
Residential · Hotel Office/ Parking
Commercial Structure
Minimum Distance Required to Meet 80 126 feet 141 feet 141 feet 141 feet d.BAL.4
It is conservatively assumed that construction activities on the project site would exceed the 80 dBA
Leq threshold at the property lines of the nearby existing residences (refer to discussion above). The
distances shown in Table 3.13-6 do not take into account pile driving activities, which would further
increase noise levels.
Mitigation Measure:
MMNOI-1.1: Construction activities under the proposed project ( or General Plan Buildout with
Maximum Residential Alternative or Retail and Residential Alternative) shall be
conducted in accordance with provisions of the City's Municipal Code which
limit temporary construction work to daytime hoius, 87 Monday through Friday.
Construction is prohibited on weekends and all holidays. Further, the City
requires that all equipment have high-quality noise mufflers and abatement
devices installed and are in good condition. Additionally, the construction crew
shall adhere to the following construction best management practices listed in
MM NOI-1.2 below to reduce construction noise levels emanating from the site
87 Pei Municipal Code Section 10.48.010, daytime is defined as the period from 7:00 AM to 8:00 PM weekdays.
Vallco Special Area Specific Plan
City of Cupertino
215 Draft Environmental Ii:npact Report
May2018
MMNOI-1.2:
and minimize disruption and annoyance at existing noise-sensitive receptors in
the project vicinity.
Future development shall implement a construction noise control plan, including,
but not limited to, the following available controls:
• Construct temporary noise barriers, where feasible, to screen stationary
noise-generating equipment. Temporary noise barrier fences would
provide a five dBA noise reduction if the noise barrier interrupts the line-
of-sight b~tween the noise source and receptor and if the barrier is
constructed in a manner that eliminates any cracks or gaps.
• Equip all internal combustion engine-driven equipment with inta;trn and
exhaust mufflers that are in good condition and appropriate for the
equipment.
• Unnecessary idling of internal combustion engines shall be strictly
prohibited.
• Locate stationary noise-generating equipment, such as air co.rnpressors or
portable power generators, as far as possible from sensitive receptors as
feasible. If they must be located near receptors, adequate muffling (with
enclosures where feasible and appropriate) shall be used to reduce noise
levels at the adjacent sensitive receptors. Any enclosure openings or
venting shall face away from sensitive receptors.
. .
• Utilize "quiet" air compressors and other stationary _noise sources where
technology exists.
• Construction staging areas shall be established at locations that would
create the greatest distance between the construction-related noise sources
and noise-sensitive receptors nearest the project site during all project
construction.
• Locate material stockpiles, as well as maintenance/equipment staging and
parking areas, as far as feasible from residential receptors.
• Control noise from construction workers' radios to a point where they are
not audible at existing residences bordering the project site.
• If impact pile driving is proposed, temporary noise control blanket
barriers shall shroud pile drivers or be erected in a manner to shield the
adjacent land uses.
• If impact pile driving is proposed, foundation pile holes shall be pre-
drilled to minimize the number of impacts required to seat the pile. Pre-
drilling foundation pile holes is a stand~d construction noise control
technique. Pre-drilling reduc~s the number of blows required to seat the
pile. Notify all adjacent land uses of the construction schedule in writing.
• The contractor shall prepare a detailed constrnction schedule for major
noise-generating construction activities and provide it to adjacent land
uses. The construction plan shall identify a procedure for coordination
with adjacent residential land uses so that construction activities can be
scheduled to minimize noise disturbance.
V allco Special Area Specific Plan
City of Cupertino
216 Draft Environmental Impact Report
May2018