B-2018-0614 CITY OF CUPERTINO BUILDING PERMIT
BUILDING ADDRESS: CONTRACTOR: PERMIT NO:B-2018-0614
10889 N DE ANZA BLVD CUPERTINO,CA 95014(326 10 058) S L C INC
VACAVILLE,CA 95688
OWNER'S NAME: DATE ISSUED:09/25/2018
OWNER'S PHONE: PHONE NO:(
BUILDING PERMIT INFO:
License Class A B Lic.#924504
Contractor S L C INC Date 11/30/2018 X BLDG —ELECT —PLUMB
I hereby affirm that I am licensed under the provisions of Chapter 9(commencing MECH_RESIDENTIAL X COMMERCIAL
with Section 7000)of Division 3 of the Business&Professions Code and that my
license is in full force and effect. JOB DESCRIPTION:
SPRINT TI-REPLACE 3 ANTENNAS AND 6 RRUS
I hereby affirm under penalty of perjury one of the following two declarations:
t. I have and will maintain a certificate of consent to self-insure for Worker's
Compensation,as provided for by Section 3700 of the Labor Code,for the
performance of the work for which this permit is issued.
t p 2. I have and will maintain Worker's Compensation Insurance,as provided for by
Section 3700 of the Labor Code,for the performance of the work for which this
permit is issued. Sq.Ft Floor Area: Valuation:$15000.00
APPLICANT CERTIFICATION
I certify that I have read this application and state that the above
information is correct.I agree to comply with all city and county ordinances APN Number: Occupancy Type:
and state laws relating to building construction,and hereby authorize 326 10 058
representatives of this city to enter upon the above mentioned property for
inspection purposes. (We)agree to save indemnify and keep harmless the
City of Cupertino against liabilities,judgments,costs,and expenses which PERMIT EXPIRES IF WORK IS NOT STARTED
may accrue against said City in consequence of the granting of this permit. WITHIN 180 DAYS OF PERMIT ISSUANCE OR
Additionally,the applicant understands and will comply with all non-point
source regulations per the Cupertino Municipal Code,Section 9.18. 180 DAYS FROM LAST CALLED INSPECTION.
Signature ) Date 09/25/2018 Issued by:Jasmine Archbold
U Date:09/25/2018
OWNER-BUILDER DECLARATION
I hereby affirm that I am exempt from the Contractor's License Law for one of the RE-ROOFS:
following two reasons: All roofs shall be inspected prior to any roofing material being installed.If a roof is
t. I,as owner of the property,or my employees with wages as their sole installed without first obtaining an inspection,I agree to remove all new materials for
compensation,will do the work,and the structure is not intended or offered for inspection.
sale(Sec.7044,Business&Professions Code)
2. 1,as owner of the property,am exclusively contracting with licensed Signature of Applicant:
contractors to construct the project(Sec.7044,Business&Professions Code). Date:09/25/2018
I hereby affirm under penalty of perjury one of the following three declarations: ALL ROOF COVERINGS TO BE CLASS"A"OR BETTER
r. I have and will maintain a Certificate of Consent to self-insure for Worker's
Compensation,as provided for by Section 3700 of the Labor Code,for the
performance of the work for which this permit is issued. HAZARDOUS MATERIALS DISCLOSURE
2. I have and will maintain Worker's Compensation Insurance,as provided for by I have read the hazardous materials requirements under Chapter 6.95 of the
Section 3700 of the Labor Code,for the performance of the work for which this California Health&Safety Code,Sections 25505,25533,and 25534. I will
permit is issued. maintain compliance with the Cupertino Municipal Code,Chapter 9.12 and the
3. I certify that in the performance of the work for which this permit is issued,I Health&Safety Code,Section 25532(a)should I store or handle hazardous
shall not employ any person in any manner so as to become subject to the material. Additionally,should I use equipment or devices which emit hazardous
air contaminants as defined by the Bay Area Air Quality Management District I
Worker's Compensation laws of California. If,after making this certificate of will maintain compliance with the Cupertino Municipal Code,Chapter 9.12 and
exemption,I become subject to the Worker's Compensation provisions of the the Health&Safety Code,Sections 25505,25533,and 25534.
Labor Code,I must forthwith comply with such provisions or this permit shall
be deemed revoked. Owner or authorized agent: `
APPLICANT CERTIFICATION Date:09/25/2018
I certify that I have read this application and state that the above information is CONSTRUCTION LENDING AGENCY
correct.I agree to comply with all city and county ordinances and state laws I hereby affirm that there is a construction lending agency for the performance
relating to building construction,and hereby authorize representatives of this city of work's for which this permit is issued(Sec.3097,Civ C.)
to enter upon the above mentioned property for inspection purposes. (We)agree Lender's Name
to save indemnify and keep harmless the City of Cupertino against liabilities,
judgments,costs,and expenses which may accrue against said City in Lender's Address
consequence of the granting of this permit. Additionally,the applicant understands
and will comply with all non-point source regulations per the Cupertino Municipal ARCHITECT'S DECLARATION
Code,Section 9.18. 1 understand my plans shall be used as public records.
Licensed
Signature Date 09/25/2018
Professional
Sprint • Base Station No. FS04xc153
10889 North De Anza Boulevard • Cupertino, California
T2TR
Page 1 of 4
Statement of Hammett & Edison, Inc., Consulting Engineers
The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained by Sprint, a personal
wireless telecommunications carrier, to evaluate proposed modifications to its existing base station (Site
No. FS04xc153) located at 10889 North De Anza Boulevard in Cupertino, California, for compliance
with appropriate guidelines limiting human exposure to radio frequency (“RF”) electromagnetic fields.
Executive Summary
Sprint proposes to add directional panel antennas behind existing view screens above the roof
of the four-story Cupertino Hotel, located at 10889 North De Anza Boulevard in Cupertino.
The proposed operation will comply with the FCC guidelines limiting public exposure to RF
energy.
Prevailing Exposure Standards
The U.S. Congress requires that the Federal Communications Commission (“FCC”) evaluate its actions
for possible significant impact on the environment. A summary of the FCC’s exposure limits is shown
in Figure 1. These limits apply for continuous exposures and are intended to provide a prudent margin
of safety for all persons, regardless of age, gender, size, or health. The most restrictive FCC limit for
exposures of unlimited duration to radio frequency energy for several personal wireless services are as
follows:
Wireless Service Frequency Band Occupational Limit Public Limit
Microwave (Point-to-Point) 5–80 GHz 5.00 mW/cm2 1.00 mW/cm2
WiFi (and unlicensed uses) 2–6 5.00 1.00
BRS (Broadband Radio) 2,600 MHz 5.00 1.00
WCS (Wireless Communication) 2,300 5.00 1.00
AWS (Advanced Wireless) 2,100 5.00 1.00
PCS (Personal Communication) 1,950 5.00 1.00
Cellular 870 2.90 0.58
SMR (Specialized Mobile Radio) 855 2.85 0.57
700 MHz 700 2.40 0.48
[most restrictive frequency range] 30–300 1.00 0.20
General Facility Requirements
Base stations typically consist of two distinct parts: the electronic transceivers (also called “radios” or
“channels”) that are connected to the traditional wired telephone lines, and the passive antennas that
send the wireless signals created by the radios out to be received by individual subscriber units. The
transceivers are often located at ground level and are connected to the antennas by coaxial cables. A
small antenna for reception of GPS signals is also required, mounted with a clear view of the sky.
Because of the short wavelength of the frequencies assigned by the FCC for wireless services, the
Sprint • Base Station No. FS04xc153
10889 North De Anza Boulevard • Cupertino, California
T2TR
Page 2 of 4
antennas require line-of-sight paths for their signals to propagate well and so are installed at some height
above ground. The antennas are designed to concentrate their energy toward the horizon, with very little
energy wasted toward the sky or the ground. This means that it is generally not possible for exposure
conditions to approach the maximum permissible exposure limits without being physically very near
the antennas.
Computer Modeling Method
The FCC provides direction for determining compliance in its Office of Engineering and Technology
Bulletin No. 65, “Evaluating Compliance with FCC-Specified Guidelines for Human Exposure to Radio
Frequency Radiation,” dated August 1997. Figure 2 describes the calculation methodologies, reflecting
the facts that a directional antenna’s radiation pattern is not fully formed at locations very close by (the
“near-field” effect) and that at greater distances the power level from an energy source decreases with
the square of the distance from it (the “inverse square law”). The conservative nature of this method for
evaluating exposure conditions has been verified by numerous field tests.
Site and Facility Description
Based upon information provided by Sprint, including construction drawings by J5 Infrastructure
Partners, dated March 14, 2018, that carrier presently has fifteen directional panel antennas – three RFS
Model APXVFRR12X-C-I20 antennas installed on separate short poles and twelve inactive antennas in
groups of four behind view screens – above the roof of the four-story Cupertino Hotel, located at
10889 North De Anza Boulevard in Cupertino. It is proposed to install remove the twelve antennas and
to install three CommScope Model DT465B-2XR directional panel antennas, one each behind the three
view screens. The six antennas would employ up to 6° downtilt, would be mounted at an effective
height of about 45 feet above ground, 7½ feet above the roof, and would be oriented in identical pairs
toward 94°T, 200°T, and 345°T. The maximum effective radiated power in any direction would be
6,270 watts, representing simultaneous operation at 3,670 watts for BRS, 2,170 watts for PCS, and
430 watts for SMR service. Also located above the roof is a microwave “dish” antenna, for
interconnection of this site with others in the Sprint network. There are reported no other wireless
telecommunications base stations at the site or nearby.
Study Results
For a person anywhere at ground, the maximum RF exposure level due to the proposed Sprint operation,
including the contribution of the microwave antenna, is calculated to be 0.019 mW/cm2, which is 1.9%
of the applicable public exposure limit. The maximum calculated level at the second-floor elevation of
any nearby building* is 1.8% of the public exposure limit. The maximum calculated level at the
* Located at least 140 feet away, based on photographs from Google Maps.
Sprint • Base Station No. FS04xc153
10889 North De Anza Boulevard • Cupertino, California
T2TR
Page 3 of 4
top-floor elevation of any nearby residence† is 0.96% of the public exposure limit. The maximum
calculated level at the top floor of the Hotel is 1.7% of the public exposure limit. It should be noted that
these results include several “worst-case” assumptions and therefore are expected to overstate actual
power density levels from the proposed operation. Levels may exceed the applicable public exposure
limit on the roof of the subject building, in front of the antennas.
Recommended Mitigation Measures
It is recommended that the roof access door be kept locked, so that the Sprint antennas are not accessible
to unauthorized persons. To prevent occupational exposures in excess of the FCC guidelines, it is
recommended that appropriate RF safety training, to include review of personal monitor use and
lockout/tagout procedures, be provided to all authorized personnel who have access to the roof,
including employees and contractors of Sprint and of the property owner. No access within 11 feet
directly in front of the Sprint antennas themselves, such as might occur during certain maintenance
activities, should be allowed while the pertinent antennas are in operation, unless other measures can be
demonstrated to ensure that occupational protection requirements are met. It is recommended that the
boundary lines be marked on the roof with blue paint to identify areas within which exposure levels are
calculated to exceed the public FCC limit, as shown in Figure 3. It is recommended that explanatory
signs‡ be posted at the roof access door, at the boundary lines, on the screens in front of the antennas
and at the antennas, readily visible from any angle of approach to persons who might need to work
within that distance.
Conclusion
Based on the information and analysis above, it is the undersigned’s professional opinion that the
proposed operation of the Sprint base station located at 10889 North De Anza Boulevard in Cupertino,
California, can comply with the prevailing standards for limiting human exposure to radio frequency
energy and, therefore, need not for this reason cause a significant impact on the environment. The
highest calculated level in publicly accessible areas is much less than the prevailing standards allow for
exposures of unlimited duration. This finding is consistent with measurements of actual exposure
conditions taken at other operating base stations. Locking the roof access door is recommended to
establish compliance with public exposure limits; training authorized personnel, marking roof areas, and
posting explanatory signs are recommended to establish compliance with occupational exposure limits.
† Including the three-story residential buildings located at least 270 feet to the west, based on photographs from Google
Maps.
‡ Signs should comply with OET-65 color, symbol, and content recommendations. Contact information should be
provided (e.g., a telephone number) to arrange for access to restricted areas. The selection of language(s) is not an
engineering matter, and guidance from the landlord, local zoning or health authority, or appropriate professionals
may be required.
Sprint • Base Station No. FS04xc153
10889 North De Anza Boulevard • Cupertino, California
T2TR
Page 4 of 4
Authorship
The undersigned author of this statement is a qualified Professional Engineer, holding California
Registration Nos. E-13026 and M-20676, which expire on June 30, 2019. This work has been carried
out under his direction, and all statements are true and correct of his own knowledge except, where
noted, when data has been supplied by others, which data he believes to be correct.
_________________________________
William F. Hammett, P.E.
707/996-5200
May 23, 2018
FCC Radio Frequency Protection Guide
FCC Guidelines
Figure 1
Frequency (MHz)
1000
100
10
1
0.1
0.1 1 10 100
103 104 105
Occupational Exposure
Public Exposure
PCS
CellFM
PowerDensity(mW/cm2)The U.S. Congress required (1996 Telecom Act) the Federal Communications Commission (“FCC”)
to adopt a nationwide human exposure standard to ensure that its licensees do not, cumulatively, have
a significant impact on the environment. The FCC adopted the limits from Report No. 86, “Biological
Effects and Exposure Criteria for Radiofrequency Electromagnetic Fields,” published in 1986 by the
Congressionally chartered National Council on Radiation Protection and Measurements (“NCRP”).
Separate limits apply for occupational and public exposure conditions, with the latter limits generally
five times more restrictive. The more recent standard, developed by the Institute of Electrical and
Electronics Engineers and approved as American National Standard ANSI/IEEE C95.1-2006, “Safety
Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to
300 GHz,” includes similar limits. These limits apply for continuous exposures from all sources and
are intended to provide a prudent margin of safety for all persons, regardless of age, gender, size, or
health.
As shown in the table and chart below, separate limits apply for occupational and public exposure
conditions, with the latter limits (in italics and/or dashed) up to five times more restrictive:
Frequency Electromagnetic Fields (f is frequency of emission in MHz)
Applicable
Range
(MHz)
Electric
Field Strength
(V/m)
Magnetic
Field Strength
(A/m)
Equivalent Far-Field
Power Density
(mW/cm2)
0.3 – 1.34 614 614 1.63 1.63 100 100
1.34 – 3.0 614 823.8/ f 1.63 2.19/ f 100 180/ f2
3.0 – 30 1842/ f 823.8/ f 4.89/ f 2.19/ f 900/ f2 180/ f2
30 – 300 61.4 27.5 0.163 0.0729 1.0 0.2
300 – 1,500 3.54 f 1.59 f f /106 f /238 f/300 f/1500
1,500 – 100,000 137 61.4 0.364 0.163 5.0 1.0
Higher levels are allowed for short periods of time, such that total exposure levels averaged over six or
thirty minutes, for occupational or public settings, respectively, do not exceed the limits, and higher
levels also are allowed for exposures to small areas, such that the spatially averaged levels do not
exceed the limits. However, neither of these allowances is incorporated in the conservative calculation
formulas in the FCC Office of Engineering and Technology Bulletin No. 65 (August 1997) for
projecting field levels. Hammett & Edison has built those formulas into a proprietary program that
calculates, at each location on an arbitrary rectangular grid, the total expected power density from any
number of individual radio sources. The program allows for the description of buildings and uneven
terrain, if required to obtain more accurate projections.
RFR.CALC ™ Calculation Methodology
Assessment by Calculation of Compliance with FCC Exposure Guidelines
Methodology
Figure 2
The U.S. Congress required (1996 Telecom Act) the Federal Communications Commission (“FCC”) to
adopt a nationwide human exposure standard to ensure that its licensees do not, cumulatively, have a
significant impact on the environment. The maximum permissible exposure limits adopted by the FCC
(see Figure 1) apply for continuous exposures from all sources and are intended to provide a prudent
margin of safety for all persons, regardless of age, gender, size, or health. Higher levels are allowed for
short periods of time, such that total exposure levels averaged over six or thirty minutes, for
occupational or public settings, respectively, do not exceed the limits.
Near Field.
Prediction methods have been developed for the near field zone of panel (directional) and whip
(omnidirectional) antennas, typical at wireless telecommunications base stations, as well as dish
(aperture) antennas, typically used for microwave links. The antenna patterns are not fully formed in
the near field at these antennas, and the FCC Office of Engineering and Technology Bulletin No. 65
(August 1997) gives suitable formulas for calculating power density within such zones.
For a panel or whip antenna, power density S = 180
BW
0.1 Pnet
D 2 h , in mW /cm 2,
and for an aperture antenna, maximum power density Smax = 0.1 16 Pnet
h 2 , in mW /cm 2,
where BW = half-power beamwidth of the antenna, in degrees, and
Pnet = net power input to the antenna, in watts,
D= distance from antenna, in meters,
h= aperture height of the antenna, in meters, and
= aperture efficiency (unitless, typically 0.5-0.8).
The factor of 0.1 in the numerators converts to the desired units of power density.
Far Field.
OET-65 gives this formula for calculating power density in the far field of an individual RF source:
power density S = 2.56 1.64 100 RFF 2 ERP
4 D2 , in mW /cm 2,
where ERP = total ERP (all polarizations), in kilowatts,
RFF = relative field factor at the direction to the actual point of calculation, and
D= distance from the center of radiation to the point of calculation, in meters.
The factor of 2.56 accounts for the increase in power density due to ground reflection, assuming a
reflection coefficient of 1.6 (1.6 x 1.6 = 2.56). The factor of 1.64 is the gain of a half-wave dipole
relative to an isotropic radiator. The factor of 100 in the numerator converts to the desired units of
power density. This formula has been built into a proprietary program that calculates, at each location
on an arbitrary rectangular grid, the total expected power density from any number of individual
radiation sources. The program also allows for the description of uneven terrain in the vicinity, to
obtain more accurate projections.
Sprint • Base Station No. FS04xc153
10889 North De Anza Boulevard • Cupertino, California
Calculated RF Exposure Levels on Roof
T2TR
Figure 3NorthRecommended Mitigation Measures
Notes: See text.
Base drawing from J5 Infrastructure Partners, Inc., dated March 14, 2018.
Calculations performed according to OET Bulletin 65, August 1997.
Shaded color
Boundary marking
Sign type
Legend:Exceeds
Occupational
- Yellow
CAUTION
N/A
blank
Less Than
Public
- Green
INFORMATION
Exceeds 10x
Occupational
- Orange
WARNING
Exceeds
Public
- Blue
NOTICE
• Lock roof access door
• Mark boundaries as shown
• Post explanatory signs
• Provide training
FEET
FEET
25 0 25 50
Calculations performed according to OET Bulletin No. 65, August 1997.
Colors shown represent percent of applicable FCC public limit.
[blank] <100%>100%>500%
FEET
25 0 25 50
Calculations performed according to OET Bulletin No. 65, August 1997.
Colors shown represent percent of applicable FCC public limit.
[blank] <100%>100%>500%
roof
access door
Sprint
antennas
courtyard