HomeMy WebLinkAboutItem 3.2Town
Town of Los Altos Hills December 9, 2004
Staff Report to the Planning Commission
RE: EXTENSION OF CONDITIONAL USE PERMIT FOR EXISTING WIRELESS
COMMUNICATIONS FACndTY; AT&T WIRELESS SERVICES, INC.
(AWS); PURISSIMA ROAD, LITTLE LEAGUE FIELDS (TOWN OF LOS
ALTOS HILLS); S); File #194 -04 -CUP.
FROM: Leslie Hopper, Project Planner
APPROVED BY: Cart Cahill, Planning Director
That the Planning Commission:
Approve the requested extension of the Conditional Use Permit for an additional 5 years,
subject to continued compliance with the original conditions of approval.
BACKGROUND
The subject parcel is located along the west side of Purissima Road, at the Little League
Fields near Viscaino Road. The site has been used as a communications facility since
1990, when the City Council granted a Conditional Use Permit to Sun Country Cable.
Over the years, the site has been leased (or sub -leased) and operated by various
communications companies, including Sun Country Cable, Cellular One, Comcast Cable
Communications, and AT&T Wireless Service. AT&T Wireless currently leases the site
and is requesting an extension of the Conditional Use Permit that was initially granted to
Cellular One in 1993 and extended in 1997. AT&T Wireless intends to continue its
normal operation and is proposing no changes at the site as stated in the letter included as
Attachment #1.
Existing equipment on the site includes 2 equipment buildings, 4 ground antenna dishes,
4 panel antennas mounted 60 feet high on a 70 -foot monopole, and another unused
monopole. The original Conditions of Approval are attached for review (see Attachment
#2). Condition #10 requires the Planning Commission to review the permit after 3 years,
prior to granting an extension.
DISCUSSION
The Conditional Use Permit was initially approved on October 20, 1993. Landscaping
and irrigation were installed, as approved by the Town, during construction of the facility.
As shown in the photos in Attachment #3, the landscaping has matured and almost
entirely screens the facility from view. The access road allows all-weather access to the
site. Maintenance visits are performed by the applicant as needed. No complaints have
been received regarding the existing communications facility.
Planning Commission
AT&T Wireless
December 9, 2004
Page 2
Conditions #10 and #12 require monitoring and reporting of radio frequency on a regular
basis to demonstrate compliance with regulatory limitations. As indicated in the attached
Statement of Hammett & Edison, Inc., Consulting Engineers, the maximum power
density level measured on August 12, 2004 was equal to 0.42% of the most restrictive
public limit on radio frequency exposure (see Attachment #4). Based on this information,
the site complies with the FCC guidelines limiting public exposure to radio frequency
energy.
Extension of the use permit will allow continued operation of the facility for an additional
period of time, at which point subsequent Commission review will be required. Staff
suggests a 5 -year review period, rather than the 3 -year review originally specified,
because the Town has not received any complaints about the site and does not anticipate
any problems with its continued use as a wireless communications facility.
CONCLUSION
No change is proposed to the existing facility. Since this facility was found to comply
with the required CUP findings when it was originally approved, and no complaints or
other problems related to the facility have been identified since that time, the Commission
should consider recommending approval of the extension to the City Council.
ATTACHMENTS:
1. Letter dated October 26, 2004 from AT&T Wireless requesting renewal -of the CUP
2. Conditions of Approval from the original approval, dated October 20, 1993
3. Photos showing landscape screening
4. Statement of Hammett & Edison, Inc., dated September 21, 2004
5. Site plans
cc: Marsha Converse, Property Management
Suite 1500
651 Gateway Blvd.
South San Francisco, CA 94080
ATTACHMENT/
AT&T
AT&T Wireless Services, Inc.
October 26, 2004 suite 1500
651 Gateway Blvd.
South San Francisco, CA. 94080
Ms. Leslie Hopper, AICP
Planning Department
Los Altos Hills
26379 Fremont Road
Los Altos Hills, CA 94022
Re: Renewal of Conditional Use Permit 194-04 for a Telecommunications facility.
Dear Ms. Hopper,
AT&T Wireless Services (AWS) is requesting renewal of the Conditional Use Permit for an existing
wireless communications facility at 27440 Purissima Road. The facility has been in operation
without interruption since 1993, when the Conditional Use Permit was originally approved. There
are no proposed changes to the site.
AWS currently has a cell site located on the west side of little league field near the south/west end.
A light pole was erected and AWS located its equipment shelter which consists of a pre -fabricated
one-story building to the hold the radios. The project was completed in a manner that reduces
adverse visual impacts and sufficient distance from public streets and surrounding residential uses.
This site was selected after an investigation of the topographic characteristics, frequency analysis,
adjacent cell interconnection, and site land -use compatibility. Maintenance of the building,
antennas and the grounds, including weed abatement and maintenance of weathering of the
building is to be accomplished on an on-going basis.
AWS incorporates the best stealth technology available to the industry today and is continuously
working to improve. Because of AWS overall network needs, and the importance of this particular
location for cellular coverage along the Purissima Road corridor we request that AWS be allowed
to extended permit and remain on site in accordance to original conditions of approval.
AWS is seeking extension of the Conditional Use Permit for another five years.
Please feel free to call me with any questions or concerns you may have.
Sincerely,
Marsha Converse
Property Management
AT&T / Cingular Wireless
650.266.2452 office
510.207.9519 mobile
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LOSALTOSHILLS
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CALIFORNIA
January 16, 1997
Ms. Elizabeth Pennington
Cellular One
651 Gateway Blvd., Suite 1500
South San Francisco, CA 94080
Re: 5-93-ZP-SD-CUP
Purissima Road
Extension of Conditional Use Permit
Dear Ms. Pennington:
ATTACHMENT4,
Your request for a Conditional Use Permit renewal was approved at the Planning Commission
meeting of January 8, 1997. The conditions for the Use Permit approved by the City Council on
October 20, 1993 apply to the renewal with a modification to condition #10. Please note the
conditions which apply to this approval:
1. All conditions of the Sun Country Cable Conditional Use Permit approved by the
City Council on February 15, 1990, shall be conditions of this approval.
2. The site drainage must be designed to meet the goal of reducing the rate of run off
associated with the proposed development. A grading and drainage plan shall be
submitted to the City Engineer for review and approval prior to issuance of a building
permit.
3. Fire retardant roofing is required for the new construction.
4. Paint color shall match the color of the Sun Country building.
5. Prior to final inspection and release of final building permits a landscape planting
plan must be submitted to and approved by the Planning Commission. No trees are
shown to be removed. If trees are damaged or removed it may be required to be
replaced. The replaced tree shall be equal in size to the removed or damaged tree up
to a maximum 24" box size tree. The landscape plan shall take into consideration
adequate screening of the equipment shelters and the existing dish antennas and
fencing.
_1379 Fremont Road
Los Altos Hills
California 94022
415/941-7222
Fax 415/941-3160
Ms. Elizabeth Pennington
January 16, 1997
Page 2
A landscape maintenance agreement shall be recorded in the office of the County
Recorder, prior to final building permit approval, agreeing to install and maintain in
good condition all required plantings. All planting required for mitigation screening
that does not establish itself within eight (8) months, shall be replaced.
A $5000.00 landscape deposit shall be posted prior to final inspection. Required
plantings shall be installed within one year, 50% of the bond shall be returned one
year after the date of the inspection to ensure adequate establishment and
maintenance. The remainder will be released one year later if the plantings remain
viable.
6. Prior to beginning any grading operation, all significant trees are to be fenced at the
drip line. The fencing shall be of a material and structure to clearly delineate the drip
line. Town staff must inspect the fencing and the trees to be fenced prior to
commencement of grading. The fence must remain throughout the course of
construction. No storage of equipment, vehicles or debris shall be allowed within the
driplines of these trees.
7. The location of the foundation is to be re -certified in writing by a registered Civil
Engineer or licensed land surveyor after the foundation has been poured as being in
the approved location and elevation established by this permit.
8. The property owner shall inform the Town of any damage and shall repair any
damage caused by construction of the project to pathways, private driveways, and
public and private roadways prior to final inspection and release of occupancy permits
and shall provide the Town with photographs of the existing conditions of the
roadways and pathway prior to issuance of building permits..
9. The Pathway shall remain open at all times.
10. The approval of the Conditional Use Permit will be reviewed in 3 years or with the
review of Sun Country Cable's Conditional Use Permit, whichever is sooner. The
application for extension of the use shall be re -reviewed by the Planning Commission
for determination of modifications necessary and for approval to continue the
Conditional Use Permit. This permit does not authorize the applicant to intensify
authorized emissions beyond that which is specifically required for communications
in the Advanced Mobile Phone System AMPS specification and as constrained by
ANSI specification C95.1-1992. Monitoring shall ensure that emissions are safe and
remain consistent with safety standards as they address exposure to the public.
Vs. Elizabeth Pennington
January 16, 1997
Page 3
11. In the event that any of the conditions of this permit are not satisfied, the Planning
Department may cause a noticed public hearing to be sent to review whether the
permit should be continued; and upon a showing of compelling public necessity
demonstrated at the noticed public hearing, the Town may add, amend, or delete
conditions and regulations contained in this permit.
12. Monitoring and reporting to the Town shall be accomplished at the installation of the
facility and once a year for three years. The reports shall be forwarded to the
Planning Commission for their information and review. If problems are noted, staff
or the Commission may agendize the report for review along with the Conditional
Use Permit at a public hearing.
13. Maintenance of the building, antennas and the grounds, including weed abatement
and maintenance of weathering of the building is required to be accomplished on an
on-going basis. The Town shall make random inspections of the property to ensure
that the required maintenance is being accomplished to the satisfaction of the Town of
Los Altos Hills.
14. Upon completion of construction, a final inspection shall be set with the Planning
Department and Engineering Department at least two weeks prior to final building
inspection approval.
Please contact us if you have any questions.
Sincerely,
Curtis S. Williams
Planning Director
cc: Planning Commission
Chair, Environmental Design and Protection Committee
Chair, Pathways Committee
Building Official
Susan Manca, Planner
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ATTACHMENT
AT&T Wireless • Base Station No. 095 $gyp I 1
27400 Purissima Road • Los Altos, California 20(14
Statement of Hammett & Edison, Inc., Consulting Engineers
The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained on behalf of AT&T
Wireless, a wireless telecommunications carrier, to evaluate the existing base station (Site No. 095)
located at 27400 Purissima Road in Los Altos, California, for compliance with appropriate guidelines
limiting human exposure to radio frequency ("RF") electromagnetic fields.
Prevailing Exposure Standards
The U.S. Congress requires that the Federal Communications Commission ("FCC') evaluate its actions
for possible significant impact on the environment. In Docket 93-62, effective October 15, 1997, the
FCC adopted the human exposure limits for field strength and power density recommended in 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 Institute of Electrical and
Electronics Engineers (`IEEE") Standard C95.1-1999, "Safety Levels with Respect to Human
Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz," includes nearly identical
exposure limits. 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 limit for exposures of unlimited duration to radio frequency energy from PCS transmissions at
1,950 MHz is 1.0 mW/cm2, applying in areas for which access by the general public is uncontrolled.
The most restrictive limit at any frequency is 0.20 MW/CM2, also applying in areas for which access by
the general public is uncontrolled.
General Facility Requirements
Antennas for base station use are designed to concentrate their energy toward the horizon, with very
little energy wasted toward the sky or the ground. Along with the low power of such facilities, this
means that it is generally not possible for exposure conditions to approach the FCC limits without
being physically very near the antennas.
Site Description
The site was visited by Mr. Rajat Mathur, a qualified engineer employed by Hammett & Edison, Inc.,
about 3:00 PM on August 12, 2004, a non -holiday weekday. AT&T had installed two pairs of
directional antennas near the top of a pole about 60 .feet tall, and several additional, unidentified
HAMMETT & EDISON, INC.
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AT&T Wireless • Base Station No. 095
27400 Purissima Road • Los Altos, California
antennas were mounted at the top of the pole, above the AT&T antennas. Access to the antennas was
controlled by their mounting height on the pole, and photos subsequently provided by AT&T show
that the fence around the pole has been locked. Because the antennas were not accessible to the
general public, no mitigation measures are necessary to comply with the FCC public exposure
guidelines. It is presumed that AT&T and the other FCC licensees located on the tower will take
adequate steps to ensure that their employees or contractors comply with the FCC occupational
exposure guidelines whenever work is required near the antennas themselves. Another similar pole
was located nearby, although there were no antennas mounted on it at the time of the visit.
Measurement Results
The measurement equipment used was a Wandel & Goltermann Type EMR -300 Radiation Meter with
Type 8 Isotropic Electric Field Probe (Serial No. P-0036). The meter and probe were under current
calibration by the manufacturer. The maximum power density level measured at any ground -level
location near the site was 0.00084 m W/cm2, which is equal to 0.42% of the most restrictive public
limit. The three-dimensional perimeter of RF power density equal to the FCC standard for
uncontrolled areas did not extend into any uncontrolled areas.
Conclusion
Based on the information and analysis above, it is the undersigned's professional opinion that the base
station installed by AT&T Wireless at 27400 Purissima Road in Los Altos, California, as installed and
operating at the time of the visit, complies with the FCC guidelines limiting public exposure to radio
frequency energy and, therefore, does not for this reason cause a significant impact on the
environment.
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, 2005. This work has been carried
out by him or under his direction, and all statements are true and correct of his own knowledge except,
where noted, when data has been su 'ed by others, which data he believes to be correct.
E-13026
M-20676
September 21, 2004
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Page 2of2
FCC Radio Frequency Protection Guide
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, which are
nearly identical to the more recent Institute of Electrical and Electronics Engineers Standard
C95.1-1999, "Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic
Fields, 3 kHz to 300 GHz." 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
Electric
Magnetic
Equivalent Far -Field
Range
Field Strength
Field Strength
Power Density
(MHz)
(V/m)
(A/m)
(mw/cm")
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
t00 180/1
3.0- 30
1842/f 823.8/f
4.89/ f 2.19/f
900/ f 180/1
30- 300
61,4 275
0.163 0.0729
1.0 0.2
300- 1,500
3.54 -If 1.59ff
ff/106 ff/138
f/300 f/1500
1,500- 100,000
137 61.4
0.364 0.163
5.0 /.o
1000
Occupational Exposure
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100
PCS
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Public Exposure
0.1 1 10 100
103 104
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Frequency (MHz)
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.
HAMMETT & EDISON, INC.
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