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HomeMy WebLinkAboutItem 3.4Item 3.4 TOWN OF LOS ALTOS HILLS May 7, 2009 Staff Report to the Planning Commission RE: CONDITIONAL USE PERMIT RENEWAL FOR AN EXISTING/ PREVIOUSLY APPROVED WIRELESS COMMUNICATIONS FACILITY. THE FACILITY CONSISTS OF THREE GROUND EQUIPMENT CABINETS ON AN A 8'X 18' CONCRETE PAD AND FOUR PANEL ANTENNAS MOUNTED TO AN EXISTING 28' TALL MONOPOLE. LANDS OF PURISSIMA HILLS WATER DISTRICT (APPLICANT: AT&T); 26451 ASCENSION DRIVE; FILE # 21 -09 - CUP FROM: Nicole Horvitz, Assistant Planner, % APPROVED BY: Debbie Pedro, AICP, Planning Director RECOMMENDATION: That the Planning Commission: Forward a recommendation to the City Council to approve the requested modification and renewal of the Conditional Use Permit be extended from five (5) years to ten (10) years in compliance with Government Code Section 65964 (b), subject to the recommended Conditions of Approval in Attachment 1. I-AXIM61 17100 On July 17, 2003, the City Council approved the Conditional Use Permit for a wireless communications facility at the Purissima Hills Water District water storage facility at 26451 Ascension Drive. The existing wireless communications facility consists of a 28' steel monopole at the east side of the Purissima Hills Water District property. Four (4) antennas are currently mounted on the pole at 24' from grade. Associated ground equipment is located on a 8'x 18' concrete pad east of the existing pump house. DISCUSSION The applicant is proposing to add eight (8) new diplexers (cables) and two (2) new RET'S (remote electrical tilt, 7"h x 2" w x 2.4" d) to the existing facility. The upgrades are designed to optimize the facility for the I Phone and 3G technology. The proposed modifications will be screened by existing vegetation on the property. Staff Report to the Planning Commission May 7, 2009 Page 2 of 5 Pursuant to Government Code Section 65964(b) the duration of time for any permit renewal for a wireless telecommunications facility should be a minimum of 10 years (currently 5 years). Staff has amended condition of approval # 2 in Attachment 1 to comply with State Law. Staff Report to the Planning Commission May 7, 2009 Page 3 of 5 Wireless Communications Facilities Policv Pursuant to the Town's Wireless Communications Policy, the applicant has submitted a 3-5 AT&T antenna master plan for the Los Altos Hills and Los Altos areas. (Attachment 4) CONCLUSION The facility is operating in compliance with conditions of the approved Conditional Use Permit and the Wireless Communications Facilities Policy. The applicant has submitted a report demonstrating that the proposed facility will operate within federal RF emissions standards and guidelines. (Attachment 3) Extension of the Use Permit will allow continued operation of the facility for an additional ten (10) years at which time subsequent Planning Commission/City Council review will be required. CEQA STATUS The proposed application is exempt from California Environmental Quality Act (CEQA) pursuant to Section 15301(a) of the CEQA Guidelines. ATTACHMENTS 1. Original Conditions of Approval (July 17, 2003) with amended condition # 2 2. Applicant's statement requesting permit renewal 3. Radio frequency emissions report by Hammett & Edison, Inc. dated January 21, 2009 4. AT&T 3-5 Year Antenna Master Plan 5. Photo Simulations 6. Wireless Communications Facilities Policy 7. Site Development Plans Attachment 1 CONDITIONAL USE PERMIT FOR A WIRELESS COMMUNICATIONS FACILITY LANDS 26451 ASCENSION DRNE: FILE # 21 -09 -CUP PLANNING DEPARTMENT: 1. Any changes or revisions to the telecommunications facility or its use shall require an amendment to the applicable conditional use permit(s). Additionally, the Planning Director may schedule a review or revocation hearing before the Planning Commission regarding the use permit, if any condition of approval is not being met or the facility is being used inconsistent with the approved use or in violation of Town development codes. 2. The use permit shall expire five (5) ten (10) years from the date of approval. Renewal of the permit must be requested in writing, with appropriate fees, prior to the expiration date. 3. The monopole shall be painted to the satisfaction of the Planning Director, prior to final inspection of the facility. The equipment units/shelters shall be painted a color, to be determined by the Planning Department, to blend with the surrounding environment prior to final inspection of the facility. 4. Landscape screening of the equipment structures may be required by the Planning Department upon final inspection, if determined to be necessary. 5. The applicant shall submit a signed agreement to the Town, agreeing that, should the use be discontinued by the carrier, all facilities will be removed not later then 90 days after discontinuance of the use or abandonment. The agreement shall be drafted by the City Attorney, and must be signed by the applicant and submitted to the Town prior to acceptance ofplans for building plan check. 6. Not later then 30 days after installation and initial operation of the antenna facility, and on or prior to January In of each year thereafter, testing of radio frequency emissions shall be conduced by qualified professionals and the reports of such testing shall be provided in writing to the Planning Department, with comparison of applicable Federal emissions standards. If at any time the emission levels we shown not to comply with Federal standards, the use permit shall be scheduled for a revocation hearing before the Planning Commission. ENGINEERING DEPARTMENT: 7. Any, and all, changes to the proposed Site Plan shall first be approved by the Town Engineering Department. No grading shall take place during the grading Staff Report to the Planning Commission May 7, 2009 Page 5 of 5 moratorium (October 15 to April 15) except with prior approval from the City Engineer. No grading shall take place within ten feet of any property line. 8. Any, and all, areas on the project site that have the native material disturbed shall be protected for erosion control during the rainy season and shall be replanted prior to final inspection CONDITION NUMBERS 5 and 8 SHALL BE COMPLETED AND SIGNED OFF BY THE PLANNING DEPARTMENT AND THE ENGINEERING DEPARTMENT PRIOR TO ACCEPTANCE OF CONSTRUCTION PLANS FOR PLAN CHECK BY THE BUILDING DEPARTMENT. Attachment 2 JAN 2 S 2009 �ATaT [OWN OF LOS ALTOS HILLS AT&T Wireless Services R E L C O M January 27, 2009 RE: AT&T Communications Facility Proposed Modifications AT&T UMTS ID: CNU 181 I—Foothill Espy Landlord Site In McCain Tank Site Address: 25451 Ascension Drive, Los Altos Hills, CA 94022 To Planning Staff: This letter will serve as a formal request to renew the existing Conditional Use Permit at the above -noted wireless facility located within the Town of Los Altos Hills. Per Staff Planner, David Keyon, I have included the following items for my renewal: —Copies of the Plans —Phowsims of Existing and Proposed Modifications —EMF Report showing Compliance with Federal, State, and Local guidelines —500' Radius mailing labels --Five-Year Plan of Wireless Facilities in Los Altos Hills --Application --Fees Please contact me if you have any questions. Thank you in advance for your cooperation. I look forward to working with you on this application. Sincerely, Jed Peters Authorized AT&T Wireless Representative ( AT&T Wireless Services R E L C O M January 27, 2009 RE: AT&T Communications Facility—Proposed Modifications AT&T UNITS ID: CNU IBI I—Foothill Expy Landlord Site 11): McCann Tank Site Address: 25451 Ascension Drive, Los Altus Hills, CA 94022 To Planning Staff: JAN 2 8 2009 TOWN OF LOS ALTOS HILLS In order in maintain our site for our customers, it is necessary to perform routine maintenance on our facility. Therefore, we are submitting the following Application in order m proceed with the following activities: Please not: We are not expanding the lease area and all work performed will be within our rights of the lease with the underlying property owner, Purissima Hills Water District. (See attached Consent Letter). Additionally, work will be performed between the weekday hours of Siam – 5pm to minimize any potential disturbance. Please contact me ifyou have any questions. Thank you in advance for your cooperation. I look forward to working with you on this application. Sincerely, Jed Peters Authorized AT&T Wireless Representative ( Attachment 3 AT&T Mobility • Base Station No. CNU1811 26451 Ascension Drive • Los Altos Hills, California Statement of Hammett & Edison, Inc., Consulting Engineers The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained on behalf of AT&T Mobility, a personal wireless telecommunications carrier, to evaluate proposed modifications to its existing base station (Site No. CNU18H) located at 26451 Ascension Drive in Los Altos Hills, 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 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 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 most restrictive FCC limit for exposures of unlimited duration to radio frequency energy for several personal wireless services are as follows: Personal Wireless Service Any,ox Frequency Occupational Limit Public Lima Broadband Radio ("BRS") 2,600 MHz 5.00 mW/cm2 1.00 mW/cm2 Advanced Wireless ("AWS-) 2,100 5.00 1.00 Personal Communication ("PCS") 1,950 5.00 1.00 Cellular Telephone 870 2.90 0.58 Specialized Mobile Radio ("SMR") 855 2.85 0.57 Long Term Evolution ("LTE") 700 2.15 0.43 [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 HAMMETT & EDISON, INC. CONSLLUNG ENGINTE AT1811596 `aS^', ruu+nsm Page I of4 AT&T Mobility • Base Station No. CNU1811 26451 Ascension Drive • Los Altos Hills, California transceivers are often located at ground level and are connected to the antennas by coaxial cables about I inch thick. Because of the short wavelength of the frequencies assigned by the FCC for wireless services, the 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. Along with the low power of such facilities, 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 attached 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 AT&T Mobility, including zoning drawings by Streamline Engineering and Design, Inc., dated December 10, 2008, that carrier presently has installed four dualband directional panel antennas, two Kathrein Model 742-264 and two Powerwave Model 7920.00, mounted on a 28 -foot steel pole sited adjacent to water tanks located at 26451 Ascension Drive in Los Altos Hills, California. It is proposed to use the existing antennas, mounted at an effective height of about 251/2 feet above ground and oriented in pairs (one of each model) toward 0°T and 1200T, to provide additional cellular service. The maximum effective radiated power in any direction would be 2,140 watts, representing simultaneous operation at 1,320 watts for PCS and 820 watts for cellular service. There are reported no other wireless telecommunications base stations installed nearby. Study Results The maximum ambient RF level anywhere at ground due to the proposed AT&T operation is calculated to be 0.023 MW/CM2, which is 3.3% of the applicable public exposure limit. The maximum calculated level on top of the adjacent 20 -foot high water tank is 32% of the occupational limit and exceeds the public limit; the maximum calculated level at the second -floor elevation of any nearby f'1' HAMMEIT & EDISON, INC. mvsm.ma®ENcm1816 AT] 811596 : n =. 111. ". Page 2 of4 AT&T Mobility • Base Station No. CNU1811 26451 Ascension Drive • Los Altos Hills, California residence' is 3.3% 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. Recommended Mitigation Measures Due to their mounting locations, the AT&T antennas are not accessible to the general public, and so no mitigation measures are necessary to comply with the FCC public exposure guidelines. To prevent occupational exposures in excess of the FCC guidelines, no access within 9 feet directly in front of the AT&T antennas themselves, such as might occurduring maintenance work on the pole, should be allowed while the base station is in operation, unless other measures can be demonstrated to ensure that occupational protection requirements are met. Posting explanatory warning signst at the antennas and/or on the pole below the antennas, such that the signs would be readily visible from any angle of approach to persons who might need to work within that distance, would be sufficient to meet FCC - adopted guidelines. Conclusion Based on the information and analysis above, it is the undersigned's professional opinion that the AT&T Mobility base station located at 26451 Ascension Drive in Los Altos Hills, California, will comply with the prevailing standards for limiting public exposure to radio frequency energy and, therefore, will 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. Posting of explanatory signs is recommended to establish compliance with occupational exposure limitations. " Located at least 145 feet away, based aerial photographs from Google Maps. t Warning signs should comply with OET-65 color, symbol, and content recommendations. Contact information should be provided (eg., 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. rffi Wri,a HAMMETT&EDISON, INC. ATI811596 ice!" CONSILTNG FNCQJL[PS 2.'*2 SLNFAANnSM Page 3of4 AT&T Mobility • Base Station No. CNU1811 26451 Ascension Drive • Los Altos Hills, California Authorship The undersigned author of this statement is a qualified Professional Engineer, holding California Registration Nos. E-13026 and M-20676, which expire on lune 30, 2009. 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. January 21, 2009 HAMMETI& EDISON, INC. Colscinwc ENCMTERS AT) 811596 t }. >`. SAN IAWCISCO Page 4 of 4 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 ("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 a0 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 If 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 1.63 219/f 100 180/f' 3.0-30 18422f 823.8/f 4.89/f 2.19/f 900/f 180/f' 30- 300 61.4 275 0.163 0.0729 1.0 0.2 300- 1,500 3.54xff I59df dr/106 df/238 f/300 )/1500 1,500- 100,000 137 61.4 0.364 0163 5.0 1.0 1000 / Occupational Exposure 00 PCS �% c� E 10 FM Cell \ 0.1 Public ESDosure 0.1 1 10 100 103 104 l05 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. vo'I " CONsm.rMGENGMEEItS FCC Guidelines ylk,m sarvvaarvasm Figure 1 RFR.CALC'm Calculation Methodology Assessment by Calculation of Compliance with FCC Exposure Guidelines 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. 1 x P For a panel or whip antenna, power density S = 180 x 0."in mW/cmz, t%w nxD xh' and for an aperture antenna, maximum power density S..= O.1x16x t' xP�, ' , in mW/DB2 nxh where OBw = 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 q = 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: 2.56 x 1.64 x 100 x RFF2 x ERP power density S = in'ny`'/cmz, 4xnxD� 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. [EW HAMMETT& EDISON, INC. corvsurnnc ENGINEERS Methodology SAR RIICISW Figure 2 ■ x. m • ., Proposed & 71+� �+ a I. �. _ a r bti� ��`'�A - . „�- = . ss 11 �. Attachment 6 TOWN OF LOS ALTOS HILLS Policy Re: Wireless Communications Facilities Code Sections Section 10-1.703(h)(2) of the Zoning Ordinance allows service uses, including "communications facilities", to be permitted in the Town if a Conditional Use Permit is granted by the Planning Commission and City Council. Section 10-1.1107(1) of the Code outlines findings which must be made to approve a use permit, including the proper location of the use or facility relative to others in the vicinity, the adequacy of the site to accommodate the use, and that the facility or use will not have an adverse effect on adjacent properties. Intent: The purpose of this policy is to outline the desired criteria for siting of wireless communications facilities, generally including monopoles, related antennas, and equipment shelters. As the Town's land use is virtually entirely residential, wireless communication facilities will be most appropriately located on public or institutional sites existing within the Town. Collocation, location on or near existing buildings, and landscape screening will be desired to minimize the visual impacts of the facilities on neighbors and the public. Policies: Priorities for Siting. Wireless communication facilities shall generally be located on properties with priority as follows: a) Town -owned properties; b) Foothill College; c) water tanks; d) other public or quasi -public facilities, such as schools or churches; and e) residential properties of at least ten (10) acres. 2. Siting on Residential Parcels. Wireless communication facilities may be permitted on properties used for residential purposes or vacant parcels intended for residential use if the residential property owner provides written consent and significant visual impacts are mitigated. Collocation. Collocation of wireless communication facilities with other facilities is encouraged to the maximum extent feasible, as long as the collocation is technologically compatible and does not substantially increase visual impacts. The Town will generally require as a condition of approval for any conditional use permit that the applicant permit collocation of other facilities, subject to technological constraints and Town review. Policy Re: Wireless Communications Facilities page 2 3a. Applications for collocation on an existing wireless communications facility shall be subject to an administrative review provided that the following requirement is met: • The collocated antennas and ground equipment shall be mounted or installed within an existing tower, building, or structure where the physical appearance of the existing facility is not altered to accommodate the additional antennas and equipment. 4. landscape Screening and Color. Landscape screening shall be required by the Town to minimize the visual impacts of wireless communication facilities. Poles, antennas, and equipment buildings should be painted to blend with the surrounding environment and/or buildings to further minimize visual impacts. 5. Environmental Review. A Negative Declaration will typically be prepared for review of proposed wireless communication facilities, with special attention to the visual impacts of the facilities. Categorical exemptions may be used where facilities are collocated with or would be minimal additions to existing structures, with negligible additional visual impact. 6. Antenna Master Plans. Any applicant for a wireless communication facility site shall submit applications, to the best of their knowledge, for all sites anticipated to be required by the carver for a three (3) to five (5) year period, and the requests shall be reviewed by the Planning Commission and City Council as a master plan application. 7. Term of Permits and Abandonment of Sites. Conditional use permits for wireless communication facilities shall be established for periods not to exceed five (5) years, at which time renewal of the permit must be requested by the applicant. More frequent review of the operation of the permit may be made a condition of approval. Approval will also require a written agreement from the applicant that, should the use be discontinued by the carrier, all facilities will be removed not later than ninety (90) days after discontinuance of the use or abandonment. Such a provision shall also be included in any lease with the Town for use of Town lands for wireless communications facilities. The Town may require bonding or other surety to assure the removal of such facilities. 8. Wireless communication firms shall, at the time of application for permits, demonstrate efforts which have been made to inform neighboring residents of the proposed facilities, such as conducting meetings, or mailing fact sheets and/or letters, etc. to neighbors. The Planning Director is authorized to reduce or waive permit fees for any wireless communications facility that is proven to expand wireless coverage in the Town and is structurally capable of co -location. Policy Re: Wireless Communications Facilities page 3 10. The planning Director is authorized to administratively approve portable wireless communications facilities also known as cell on wheels or COWS on certain properties as specified in Policy #1 on a temporary basis. Approved by City Council: August 21, 1996 Amended September 15, 2005 Amended October 12, 2006