Exhibits for Public Hearing held on August 9, 2004
B Proof of Publication C Garfield Count D E A lication F Staff Memorandum BOCC 08109104 FJ
PROJECT INFORMATION AND STAFF COMMENTS
REOUEST Special Use Permit for a "Communications Facility"
OWNER I APPLICANT Chad & Kristin Campbell
REPRESENTATIVE Gamba & Associates
LOCATION NW \I.I of the SE \I.I of Section 16, Township 7 South, Range 95 West of the 6'h PM; practically located 1.5 miles east of Battlement Mesa
SITE DATA 40 acres
ACCESS CR 302 (Underwood Lane)
EXISTING ZONING ARRD
SUROUNDING ZONING ARRD I Open Space (BLM)
I. DESCRIPTION OF THE PROPOSAL The Applicant proposes to erect a 60-foot tall translator tower on a privately owned 40-acre property located just east of the Battlement Mesa community. The property is zoned ARRD and is surrounded to the south and east by BLM and by ARRD to the north and west. The purpose for the proposed tower is to transmit an FM signal from a Grand Junction radio station to rural areas obscured by topography. The tower is comprised of three sections that total 48 feet. A 12-foot antenna is placed on top of the tower for a total height of 60 feet. The tower is free standing and uses no wires. The translator (FM) is a small box measuring 19" wide, 8" high, and 15" deep which emits 34 watts with a frequency of 101.9 and is mounted at the base of the tower and is enclosed in a cabinet. Electrical power (underground) to the site will be provided by Holy Cross Electric. The area around the base of the tower will be enclosed with a 6 foot high chain-link fence. This type of structure (and its associated use) is defined in the Zoning Resolution as a Communications Facility which is contemplated in the ARRD zone district as a special use.
II. SITE DESCRIPTION As mentioned above, the property is bordered by BLM to the south and east and by private lands to the north and west. It is located just east of the Battlement Mesa community. The 40-acre property is presently improved with a single-family dwelling and water tank the remaining portion of the property consists of relatively flat open land with some mature pinion vegetation and sage brush I scrub oak used for the grazing of horses. The south portion of the far rear of the lot where the tower is proposed sits at the toe of significant slopes that stretch southward and eastward into BLM. eliminating visual impact in low light periods.
Staff agrees that the tower structure is relatively thin (28" wide at the bottom and approximately 12" at the top) does not use guide wires, is not lighted, and will be located such that the backdrop of steep slopes behind the tower will significantly reduce the visual impact. Further, due to the remote location of the tower, in that, it will be situated on the rear of a 40- acre tract and approximately I to 1.5 miles from any developed area also reduces its visual impact to the general public. Staff finds this standard is met.
B. Section 5.03.13 Review Standards: Communication Facilities Such communication facility shall be approved by the FCC and the FAA, where appropriate. In addition, the following standards will be used in the review application for a communication facility:
1. All facilities shall comply with the radio ji·equency emission requirements of the Federal Communications Commission (FCC) and any facility in compliance cannot be denied.
Staff Finding Regarding compliance with the Federal Aviation Administration (FAA), the Applicant sent the proposal to the FAA and received a "Determination of No Hazard to Air Navigation" which is included in the application binder. The FAA's letter stated:
This aeronautical study revealed that the structure does not exceed the obstruction standards and would not be a hazard to air navigation.
Based on this elevation, marking and lighting are not necessary for aviation safety. However, if marking and! or lighting are accomplished on a voluntary basis, we recommend it be installed and maintained in accordance with FAA advisory Circular 7017460-1AC70I7460-JK.
This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency (ies) andpower. Any changes in coordinates, heights, and frequencies or use ofgreater power will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.
This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA.
This determination concerns the effect ofthis structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance 3 III.REFERRALS Staff referred the application out to the following review agencies and or County Departments:
a. Town of Parachute: No comments received. b. Battlement Mesa: No comments received. c. Bureau of Land Management: No comments received.
IV. COMPREHENSIVE PLAN The property lies within Study Area 3 and is designated on the proposed land use map as outlying residential. The proposed tower is not located in any defined visual corridor or any urban areas of influence as mapped in the plan.
V. REVIE\V STANDARDS Special Uses are subject to the standards in Section 5.03 of the Zoning Resolution. In addition, the proposed use shall also be required to address the standards fro a communications facility found in Section 5.03.13 of the Zoning Resolution. These review standards are presented below followed by a response by Staff.
A. Section 5.03 Review Standards
1) Utilities adequate to provide water and sanitation service based on accepted engineering standards and approved by the Board ofCounty Commissioners shall either be in place or shall be constructed in conjunction with the proposed use;
Staff Finding The proposed tower is an unmanned stand-alone structure which requires no utilities for providing water or a method for dealing with wastewater. This standard is met. 2) Street improvements adequate to accommodate traffic volume generated by the proposed use and to provide safe, convenient access to the use shall either be in place or shall be constructed in conjunction with the proposed use;
Staff Finding The existing access to the property is County Road 302. Proposed traffic generated to the site for the tower will be approximately I trip to and from the site every three months. This does not represent any measurable impact on the County road system. This standard is met.
3) Design ofthe proposed use is organized to minimize impact on andfrom adjacent uses ofland through installation ofscreen fences or landscape materials on the periphery of the lot and by location ofintensively utilized areas, access points, lighting and signs in such a manner as to protect established neighborhood character;
Staff Finding The zoning for this property allows structures to be up to 25 feet tall. The proposed tower will exceed this height limitation by 35 feet. The application states that the tower is inherently small of profile and is located on a down slope to prevent being silhouetted against the sky. The Federal Aviation Administration (FAA) does not require the tower to be lighted 2 responsibilities relating to any law, ordinance, or regulation ofany Federal, State, or local government body.
Therefore, the FAA has approved the tower. Staff suggests that should the Board approve the request, these points above be considered conditions of approval. This standard is met.
Further, the application states that the proposed tower and the emanating frequencies have been approved by the FCC under a permit number ofBNPFT-2003081 IADV. The application also contains a print-out of a form from the FCC website that indicates an approval from the FCC for 101.9 MHZ. Staff contacted the FCC regarding the form and the tower and its frequency has been approved by the FCC. This standard is met.
2. The co-location of telecommunication facilities on one site is encouraged and the denial of a landowner/ lessor of the co-location of a site shall be based on technical reasons, not on competitive interests. It is the County's policy to minimize the number of communication facilities by the encouragement of co-locating such facilities.
Staff Finding The application states that Maranatha Broadcasting investigated other co-location opportunities and that the other towers in the area were not acceptable for the proposed facility. In an additional supplement at the request of Staff, the Applicant elaborated on their endeavors and provided the following reasons why co-location was not a possibility:
"Maranatha has three FM stations, two of which are presently rebroadcast in Garfield County, K-JOY 92.3 and Magic 93.1. We hope to add the signal from another one of our stations, Moose Country 100.7, in the near future. For a translator signal to reach Rifle, an intermediate hop between Rifle and Grand Junction needs to be established. A site east of Battlement Mesa that is line of site to Anvil Points is ideal. Both the proposed Kimball property site and Dog Head Electronics Site (owned by American Tower) reach Anvil Point. And both our proposed site and Dog Head reach Parachute/Battlement Mesa."
Point #I: Interference "We are concerned about interference. If two antennas are positioned too close to each other, they will interfere with each other. On FM, this takes the form of noise, hiss, and loss of frequency response - all of which result in a decrease in the quality of service being provided to residents of Garfield County. On cellular, this takes the form of noise, dropped calls, and voice distortion. With FM, transmit and receive antennas need to be separated by 10 feet vertically, or perhaps as much as I 00 feet horizontally to eliminate interference. We think adding another 3 FM translators at the existing, crowded Dog Head site has the likelihood to cause numerous interference issues, issues that may never be completely eliminated."
"We are also concerned about interference from services outside the FM band. There are dozens of transmitters at Dog Head, representing numerous services in a wide range of frequencies like wireless, two-way, FM translator, TV translator, business band, public safety, etc. Adding three additional FM signals on Dog Head to the already crowded spectrum, with 4 each frequency having multiple harmonics, and then concentrating them all within a few feet of each other, plus resolving all the combinations and permutations of the intermixing of all the frequencies together is a serious concern. We need to receive 4 crystal clear signals from the FM band, as well as be able to transmit 4 crystal clear signals. This is much easier to accomplish when the antennas are widely separated from each other, as we are proposing with the Kimball property site."
"Interference is difficult to predict and remove. At Black Ridge Electronic Site (above Grand Junction) one of our primary FM stations has caused interference with a cellular provider. Tens of thousands of dollars have been invested to correct this interference, all to no avail. The station's transmitter is within specifications, so the cellular provider will either have to live with the interference, or move off the site. Another example of interference on a crowded site was Gray Head Mountain near Telluride. There, an FM translator caused interference to San Miguel County emergency services. That interference issue is still not satisfactorily resolved."
Point #2: Unreasonable Fees "A second concern is fees. Maranatha Broadcasting and translator operators, who rebroadcast our signals, expect to pay reasonable fees for our translator sites. In our opinion, the Dog Head site on BLM land has become unreasonable. Below are found the potential numbers of listeners at each site, and the approximate fees at each site."
Montrose, CO 12,000 people $250 I month 2.1 ¢ I person Cedaredge, Orchard City, CO 5,000 $100 I month 2.0¢ I person Moab, UT 5,000 $100 I month 2.0¢ I person Rifle, CO 5,000 $125 I month 2.5¢ I person Eagle, Gypsum, CO 5,000 $120 I month 2.4¢ I person
However, American Tower at Dog Head Electronic Site proposes the following base rate:
Parachute, Battlement Mesa 3,000 people $500 I month 16.6¢ I person
"We think a rate 8 times higher than those at comparable sites is unfair and unreasonable. Our translators serve thousands of Garfield County citizens with news, weather and unique programming. K-JOY is also the primary Emergency Alert Station, not only for our home Mesa County, but for Garfield County as well. Emergency messages go out immediately on all our stations as they come to us from the Weather Service, State of Colorado, Department of Homeland Security, and various county governments. We have been serving Garfield County in this capacity since the EAS system started. We hope to keep serving the people of Garfield County, but costs need to be reasonable."
Based on the foregoing, the Applicant finds that interference with other translators (FM, TV, cellular providers, etc.) would diminish their FM service and possibly jeopardize the transmission of public safety information. Further, this supplemental information admits that co-location continues to be possible by the number and varied type ofuses already co-locating at the Dog Head site. No technical data was provided to support this finding. Lastly, the 5 applicant is also concerned with the inflated cost of the base fee ($500 per month) charged at the American Tower at Dog Head Electronic Site. As an interesting note, the standard above states that ... [inter-alia J the denial ofa landowner/ lessor of the co-location of a site shall be based on technical reasons, not on competitive interests. The Applicant makes a point in stating that an existing tower site is charging "a rate 8 times higher than those at comparable sites which is unfair and unreasonable." Arguably, the tower owner and not this applicant is in conflict with this language. Co-location should be allowed except where technical reasons such as interference preclude additional users. In the same manner, the Applicant's proposed tower should be available for additional users at a reasonable rate and can only deny co-location requests for technical reasons. This standard is met.
3. A freestanding telecommunication facility, including antennas, shall not exceed the maximum structure height (25 feet) in the applicable zone district unless an exception is approved by the Board based on the applicant demonstrating the following:
a. Use of existing land forms, vegetation and structures to aid in screening the facility from view or blending in with the surrounding built natural environment;
Staff Finding As mentioned above, Staff finds that the tower structure is relatively thin (28" wide at the bottom and approximately 12" at the top) does not use guide wires, is not lighted, and will be located such that the backdrop of steep slopes behind the tower will significantly reduce the visual impact and allow it to blend with the surrounding environment rather than skyline against the open sky. Further, due to the remote location of the tower, in that, it will be situated on the rear of a 40-acre tract and approximately 1 to 1.5 miles from any developed area also reduces its visual impact to the general public. Staff finds this standard is met.
b. Design, materials and colors ofantennas and their support structures, shall be compatible with the surrounding environment, and monopole support structures shall taper from the base to the tip; and
Staff Finding The proposed tower is a mono-pole design that tapers from the base to the tip. The Antenna is an FM Dipole Antenna. The application contains the technical specifications (dimensions) of the both the support tower and the antenna. The tower is constructed of gray colored steel. The design of the tower is ofa tripod construction (three sides) that is approximately 28" wide at the base tapering to approximately 10-12" at the top ( 48 feet) where a 12-foot antenna mast (monopole) is attached that will hold the actual antennas. These dimensions outline a tower that is relatively "thin" and also does not use guide wires for additional support. However, Staff suggests, should the Board approve the request, that the Applicant indicate that all colors used on the tower shall not make the tower reflect light or stand out from the surrounding and background vegetation. 6 c. It is consistent with existing communication facilities on the same site.
Staff Finding There are no other communication facilities on the same property. This standard is met.
VI. STAFF RECOMMENDATION Staff recommends the Board of County Commissioners approve the request for a Special Use Pe1mit for a "Communications Facility" for a property owned by Chad & Kristin Campbell located in the NW \,,; of the SE \
VII. RECOMMENDED MOTION "I move to approve a Special Use Permit for a Communications Facility" for a property owned by Chad & Kristin Campbell located in the NW \'4 of the SE \'4 of Section 16, Township 7 South, Range 95 West of the 6'h PM; practically located 1.5 miles east of Battlement Mesa with the following conditions:
I) That all representations made by the Applicant in the application and as testimony in the public hearing before the Board of County Commissioners shall be considered conditions of approval, unless specifically altered by the Board of County Commissioners.
2) The Applicant shall continuously remain in compliance with the requirements of the Federal Aviation Administration (FAA), as stated in the "Determination of No Hazard to Air Navigation" including:
a. Based on this elevation, marking and lighting are not necessary for aviation safety. However, if marking and/ or lighting are accomplished on a voluntary basis, we recommend it be installed and maintained in accordance with FAA advisory Circular 70/7460-1 AC70 I 7460-IK.
b. This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency (ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.
c. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA.
d. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation ofany Federal, State, or local
7 government body.
3) That all colors used on the tower, if any, shall not make the tower reflect light or stand out from the surrounding and background vegetation.
4) The tower shall be available for additional users to co-locate on the tower at a reasonable rate and the owner of the tower can only deny co-location requests for technical reasons.
8 ) ) EXHIBIT '
------~ Maranatha Broadcasting " 1360 E. Sherwood Drive Grand Junction, Colorado 81501 (970) 254-2100 Fax 245-7551
June 9, 2004
Fred A. Jarman, AICP, Senior Planner Garfield County Building & Planning Dept. 108 8th Street, Suite 201 Glenwood Springs, CO 81601
RE: Special Use Permit request for a "Communications Facility"
Dear Mr. Jarman,
Maranatha Broadcasting has proposed to erect a tower on the Kimball property east of Battlement Mesa. This letter further explains the efforts Mara natha Broadcasting has made towards eliminating other co-location possiblities, and why those alternatives have been rejected.
Maranatha has three FM stations, two of which are presently rebroadcast in Garfield County, K-JOY 92.3 and Magic 93.1. We hope to add the signal from another one of our stations, Moose Country 100.7, in the near future. For a translator signal to reach Rifle, an intermediate hop between Rifle and Grand Junction needs to be established. A site east of Battlement Mesa that is line of site to Anvil Points is ideal. Both the proposed Kimball property site and Dog Head Electronics Site (owned by American Tower) reach Anvil Point. And both our proposed site and Dog Head reach Parachute/Battlement Mesa.
We are concerned about interference. If two antennas are positioned too close to each other, they wi ll interfere with each other. On FM, this takes the form of noise, hiss, and loss of frequency response - all of which result in a decrease in the quality of service being provided to residents of Garfield County. On cellular, this takes the form of noise, dropped calls, and voice distortion. With FM, transmit and receive antennas need to be separated by 10 feet vertically, or perhaps as much as 100 feet horizontally to eliminate interference. We think adding another 3 FM translators at the existing, crowded Dog Head site has the likelihood to cause numerous interference issues, issues that may never be completely eliminated.
' I
KMGJ 93.1 KJYE 92.3 KMOZ 100.7 KNZZ 1100 KTMM Page 2
We are also concerned about interference from services outside the FM band. There are dozens of transmitters at Dog Head, representing numerous services in a wide range of frequencies like wireless, two way, FM translator, TV translator, business band, public safety, etc. Adding three additional FM signals on Dog Head to the already crowded spectrum, with each frequency having multiple harmonics, and then concentrating them all within a few feet of each other, plus resolving all the combinations and permutations of the intermixing of all the frequencies together is a serious concern. We need to receive 4 crystal clear signals from the FM band, as well as be able to transmit 4 crystal clear signals. This is much easier to accomplish when the antennas are widely separated from each other, as we are proposing with the Kimball property site.
Interference is difficult to predict and remove. At Black Ridge Electronic Site (above Grand Junction) one of our primary FM stations has caused interference with a cellular provider. Tens of thousands of dollars have been invested to correct this interference, all to no avail. The station's transmitter is within specifications, so the cellular provider will either have to live with the interference, or move off the site.
Another example of interference on a crowded site was Gray Head Mountain near Telluride. There an FM translator caused interference to San Miguel County emergency services. That interference issue is still not satisfactorily resolved.
A second concern is fees. Maranatha Broadcasting and translator operators who rebroadcast our signals, expect to pay reasonable fees for our translator sites. In our opinion, the Dog Head site on BLM land has become unreasonable. Below are found the potential numbers of listeners at each site, and the approximate fees at each site. Montrose, CO 12,000 people $250/month 2.1¢/person Cedaredge, Orchard City, CO 5,000 $100/month 2.0¢/person Moab, UT 5,000 $100/month 2.0¢/person Rifle, CO 5,000 $125/month 2.5¢/person Eagle, Gypsum, CO 5,000 $120/month 2.4¢/person
However, American Tower at Dog Head Electronic Site proposes the following base rate: Parachute, Battlement Mesa 3,000 people $500/month 16.6¢/person We think a rate 8 times higher than those at comparable sites is unfair and unreasonable. Page 3
Our translators serve thousands of Garfield County citizens with news, weather and unique programming. K-JOY is also the primary Emergency Alert Station, not only for our home Mesa County, but for Garfield County as well. Emergency messages go out immediately on all our stations as they come to us from the Weather Service, State of Colorado, Department of Homeland Security, and various county governments. We have been serving Garfield County in this capacity since the EAS system started. We hope to keep serving the people of Garfield County, but costs need to be reasonable.
Thanks for your help.
Jim Terlouw, GM, Maranatha Broadcasting [email protected] 970 254 2112 • • FCC Home Page Commissioners Bureaus!Oflices Finding Info
Application Search Details File Number: BNPFT-20030811ADV Call Sign: K270AY Facility Id: 152271 FRN: 0008607855 Applicant Name: PROFESSIONAL ANTENNA, TOWER AND TRANSLATOR SERVICE (PAITS) Frequency: 101.9 Channel: 270 Community of License: BAITLEMENT MESA, CO Application Type: ORIGINAL CONSTRUCTION PERMIT Status: GRANTED Status Date: 07/30/2004 Expiration Date: 07/30/2007 NCE Supplement Date: Tolling Code: Application Service: FX Disposed Date: 07/30/2004 Accepted Date: 10/10/2003 Tendered Date: 09/10/2003 Amendment Received 09/09/2003 Date: Last Public Notice: 08/04/2004 Last Report Number: 45791
Authorization \li~wAuthod~ http://svartifoss2.fcc.gov/cgi-bin/ws.exe/prod/cdbs/pubac .. ./a pp_ Authorizing Official: Official Mailing Address: PROFESSIONAL ANTENNA, TOWER AND TRANSLATOR E George H. Gwinn P.O. BOX 1738 Supervisory Engineer 12469 64. 50 ROAD Audio Division MONTROSE co 81401 Media Bureau Grant Date: July 30, 2004 Facility Id: 152271 This permit expires 3:00 a.m. Call Sign: K270AY local time, 36 months after the Permit File Number: BNPFT-20030811ADV grant date specified above. Commission rules which became effective on February 16, 1999, have a bearing on this construction permit. See Report & Order, Streamlining of Mass Media Applications, MM Docket No. 98-43, 13 FCC RCD 23056, Para. 77-90 (November 25, 1998); 63 Fed. Reg. 70039 (December 18, 1998). Pursuant to these rules, this construction permit will be subject to automatic forfeiture unless construction is complete and an application for license to cover is filed prior to expiration. See Section 73.3598. Name of Permittee: PROFESSIONAL ANTENNA, TOWER AND TRANSLATOR SERVICE (PATTS) Principal community to be served: CO-BATTLEMENT MESA Primary Station: KJYE (FM) 'Channel 222, GRAND JUNCTION, co Via: Direct - off-air Frequency (MHz): 101.9 Channel: 270 Hours of Operation: Unlimited FCC Form 351A October 21, 1985 Page 1 of 3 Call sign: K:.:!"/UAY Permit No. BNPFT-20030811ADV ·Antenna Coordinates: North Latitude: 39 deg 26 min 17 sec West Longitude: 108 deg 00 min 03 sec Transmitter: Type Accepted. See Sections 73.1660, 74.1250 of the Commissio1 Antenna type: (directional or non-directional): Non-Directional Major lobe directions (degrees true) : Not Applicable Horizontally Vertically Polarized Polarized Antenna: Antenna: Effective radiated power in the Horizontal Plane (kw): 0.034 Height of radiation center above ground (Meters) : 11 Height of radiation center above mean sea level {Meters) : 1844 Antenna structure registration number: Not Required Overall height of antenna structure above ground: 11 Meters Obstruction marking and lighting specifications for antenna structure: It is to be expressly understood that the issuance of these specifications is in no way to be considered as precluding additional or modified marking or lighting as may hereafter be required under the provisions of Section 303(q) of the Communications Act of 1934, as amended. None Required Special operating conditions or restrictions: 1 Prior to commencing program test operations, FM Trans~ator or FM Booster permittee must have on file at the Commission, FCC Form 350, Application for an FM Translator or FM Booster Station License, pursuant to 47 C.F.R. Section 74.14. 2 The permittee/licensee in coordination with other users of the site must reduce power or cease operation as necessary to protect persons having access to the site, tower or antenna from radiofrequency electromagnetic fields in excess of FCC guidelines. FCC Form 351A October 21, 1985 Page 2 of 3 Callsign: K~"/UAY Permit No.: BNPFT-20030811ADV Special operating conditions or restrictions: 3 Warning signs which describe the radiofrequency electromagnetic field must be posted at appropriate intervals. Access must be restricted to prevent the exposure of humans to RF emissions in excess of the FCC guidelines (OET Bulletin No. 65, Edition 97-01, released August 1997). Permittee shall submit documentation of compliance with this special operating condition when filing FCC Form 350, application for license. *** END OF AUTHORIZATION *** FCC Form 351A October 21, 1985 Page 3 of 3 KNZZ KJYE KMGJ KMOZ KTMM KDTA Memo To: Garfield County Building and Planning Department From: Jim TerLouw, GM Date: 8/9/2004 Re: Electromagnetic Radiation at the The Staff had a concern about the radio frequency radiation emanating from the KJYE translator. In response: The Office of Engineering and Technology of the Federal Communications Commission has adopted limits for radio frequency radiation from broadcast stations. The limit for the FM band (88 to 108 MHz) is 0.2 mW/cm2 for the general population. An accompanying chart shows that no radiation in excess of this amount is received at a distance of 19 feet from the FM antenna. Since the antenna is at the 60-foot level, no significant radiation reaches ground level. Antennas used for FM radio broadcast stations normally consist of an array of elements stacked vertically and typically side-mounted on a tower. The elements are usually spaced about one wavelength apart and are fed in phase with power distributed equally among the elements. FM radio stations transmit in the 88-108 MHz band. Consulting Table 1 in Appendix A of OET Bulletin 65 ~hows that at these frequencies the MP~ l~mit for general 2 pcpulation/uncontrolled exposure 1s 0.2 mW/cm2 (200 µW/cm ) and the lumt for 2 occupational/controlled exposure is 1 mW/cm2 (1000 µW/cm ). Section 2 of Bulletin 65 explains how calculations can be performed to predict RF field-strength or power density near various antennas, including those used for FM radio transmissions. In addition, in 1985, the Environmental Protection Agency (EPA) developed a computer model for estimating ground-level power densities in the vicinity of typical FM broadcast towers. The EPA model estimates power densities in the vicinity of typical FM broadcast antennas for various antenna types and patterns. With some minor modifications, the FCC has successfully used this model over the past several years to predict ground-level power densities near FM towers. The EPA model considers the following variables of an FM antenna in arriving at is predictions: (1) the total effective radiated power (both horizontal and vertical), (2) the height above ground to the center of radiation of the antenna, (3) the type of antenna element used in the antenna array and (4) the number of elements (or bays) in the antenna array. The model is discussed in detail in an EPA publication by P. Gailey and R Tell (Reference 11 in Bulletin 65). The FCC' s version of the FM computer model can be downloaded from the FCC's Office of Engineering and Technology World Wide Web site.3 The FM computer model uses element and array radiation patterns to develop predicted field strengths and power densities on the ground.4 Ground reflection is taken into account in these calculations (a factor of 1.6 for field strength as discussed in Section 2 of Bulletin 65). Although the model is theoretical, measurements made by the EPA and by others around existing FM antenna towers have shown good agreement with predicted values. 3 The FCC's FM computer model ("FM Model") may be downloaded via the Internet from the FCC's Web Site at http://www.fcc.gov/oet/info/software/. Any furore revisions to this software may be found at this location. For further details contact: rf [email protected] or the FCC's RF Safety Program at (202) 418-2464. 4 The EPA measured the vertical radiation patterns of several element types and incorporated the measurement data into its computer model. The FCC has also used the EPA element pattern data and has added Other data submitted by manufacrurers for additional antenna elements. 11 Appendix J - 21 ;•.= Main-Bea1n Exposure (No Reflection) 100000 ~- 10000 ;:;-- 1000 s ~ "' > :g ~.....,, 100 El • • ./ Q. 0 "'- . ·~ "'- ~ ' • •Oa i:: :p "'0) • "'- ./.a "'9000 . ~ Cl • . v '.:;,;, tv .... 10 0) ~Oo, . ~ ' '. ' ' ' ' I • ' > ' ' ' ' ' I I . t I ' I ' ( t 'I . I I ' I ' I I I 1 10 100 1000 10000 6 fr!-e,ferJ - Distance From Antenna (meters) ;91 FIGUREl.