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HomeMy WebLinkAbout41965 NIER report 326 Tryon Road Raleigh, North Carolina 27603 (815) 721-6954 WWW.TEPGROUP.NET Non-Ionizing Radiation (NIER) Study Site Number: 419657 Site Name: Bridger View MT Location: Bozeman, Montana Tenant: Verizon Wireless, T-Mobile Prepared For: American Tower, Inc. Woburn, Massachusetts September 17, 2026 63174 P-535030 Prepared By Approved By Gautam J. Sopal Tower Engineering Professionals TEP Engineering, PLLC TEP Is a family of companies licensed to provide different services in different Jurisdictions. Depending on the jurisdiction, professional engineering and land Surveying services are provided by TEP OpCo LLC, a Delaware limited liability Company, TEP Engineering, PLLC, a North Carolina professional limited liability Company, or M&H Engineering, PLLC, a New York professional limited Liability company. General contractor services are provided by TEPDB OpCo LLC, A Delaware limited liability company. We acquire the requisite licenses in each State. Additional information can be obtained from the company. 223345 2 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Contents DISCLAIMER NOTICE .............................................................................................................................. 3 INTRODUCTION ........................................................................................................................................ 4 SITE AND FACILITY CONSIDERATIONS ............................................................................................ 4 POWER DENSITY CALCULATIONS ..................................................................................................... 4 SITE MITIGATION & CONTROL ............................................................................................................. 5 MITIGATION DRAWINGS ........................................................................................................................ 6 COMPLIANCE DETERMINATION .......................................................................................................... 6 APPENDIX 1 SITE PHOTOS ............................................................................................................ 7 APPENDIX 2.1 ANTENNA INVENTORY ............................................................................................ 8 APPENDIX 2.2 ANTENNA INVENTORY ............................................................................................ 9 APPENDIX 2.3 ANTENNA INVENTORY .......................................................................................... 10 APPENDIX 3.1 MPE LIMIT STUDY GENERAL POPULATION .................................................... 11 APPENDIX 3.2 MPE LIMIT STUDY OCCUPATIONAL LIMIT ....................................................... 12 APPENDIX 3.3 MPE LIMIT STUDY GENERAL POPULATION – HORIZONTAL VIEW .......... 13 APPENDIX 3.4 MPE LIMIT STUDY OCCUPATIONAL LIMIT – HORIZONTAL VIEW ............. 14 APPENDIX 4.1 BARRIER & SIGN TYPES ....................................................................................... 15 APPENDIX 4.2 BARRIER & SIGN TYPES ....................................................................................... 16 APPENDIX 5 INFORMATION PERTAINING TO MPE STUDIES ............................................. 17 APPENDIX 6 MPE STANDARDS METHODOLOGY .................................................................. 19 3 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Disclaimer Notice This work is based upon our best interpretation of available information. However, these data and their interpretation are constantly changing. Therefore, we do not warrant that any undertaking based on this report will be successful, or that others will not require further research or actions in support of this proposal or future undertaking. In the event of errors, our liability is strictly limited to the replacement of this document with a corrected one. Liability for consequential damages is specifically denied. Any use of this document constitutes an agreement to hold Tower Engineering Professionals and its employees harmless and indemnify it for all liability, claims, demands, and litigation expenses and attorney’s fees arising out of such use. Work product documents released prior to account settlement remain the sole property of Tower Engineering Professionals and must be returned on demand. Underlying work notes and data relating to this document remain the property of Tower Engineering Professionals. This document shall not be reproduced in whole or part without the permission of Tower Engineering Professionals. Any dispute hereunder shall be adjudicated in North Carolina. Any use or retention of this document constitutes acceptance of these terms, the entire work product, and all charges associated therewith. COPYRIGHT © 2026 BY TOWER ENGINEERING PROFESSIONALS RALIEGH, NORTH CAROLINA 4 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Non-Ionizing Electromagnetic Radiation (NIER) Study 419657 Bridger View MT Bozeman, Montana INTRODUCTION Tower Engineering Professionals RF Design & Services Division (TEP-RF) of Raleigh, North Carolina, has been retained by American Tower, Inc. (ATC), of Woburn, Massachusetts to evaluate the RF emissions compared to the Maximum Permissible Exposure (MPE) limit for facilities at this location. This evaluation uses compliance standards as outlined in Federal Communications Commission (FCC) document OET-65. SITE AND FACILITY CONSIDERATIONS Site Number 419657 Site Name Bridger View MT Address 705 Bridger Dr., Bozeman, Montana Co-ordinates 45.703589, -111.026992 Structure Type Monopole Structure Height 80 ft Tenants Verizon Wireless (VZW), T-Mobile (TMO) POWER DENSITY CALCULATIONS Power densities were calculated based on FCC MPE limits for both General Population/Uncontrolled and Occupational/Controlled environments. For the purpose of this study, a radius of 200’ from the base of the monopole with heights of 6’ above ground level and the antenna centers of radiation were used. Beyond 200’ the MPE levels become di minimus. This study utilized FCC recognized and accepted software programs using the maximum ERP levels for the antenna models provided by ATC. Diagrams depicting the predicted spatial average power density level at any specific location may be found in Appendix 3, MPE Limit Study. Descriptions of RF signage can be found in Appendix 4, Barrier & Sign Types. A discussion regarding the FCC limits may be found in Appendix 5, Information Pertaining to MPE Studies. Prediction Models used in this study may be found in Appendix 6, MPE Standards Methodology. 5 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA All data used in this study was collected from one or more of the following sources: • ATC furnished data and does not include other unidentified communication facilities. • Load List at 419657 Bridger View MT RF NIER Study 09/08/2026. • FCC databases. • Carrier standard configurations. • Empirical data collected by TEP. SITE MITIGATION & CONTROL In order to comply with FCC, tenant, & ATC requirements, TEP recommends the placement of signage at the following points: Site Entrance 1. Site ID Sign (tower owner defined) 2. RF Information Sign (Green) Tower Access Point 1. RF Exposure Sign (Yellow) Alpha Sector No additional mitigation is required. Beta Sector No additional mitigation is required. Gamma Sector No additional mitigation is required 6 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA MITIGATION DRAWINGS COMPLIANCE DETERMINATION Based on the findings of this report and signage information provided by ATC, TEP-RF has determined that this installation IS in compliance with current FCC MPE limits as described in FCC OET-65. 1. Mitigation Diagram – Site Access Point (Green) 2. Mitigation Diagram – Tower Access Point (Yellow) 7 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 1 Site Photos Aerial View of the Site 8 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 2.1 Antenna Inventory Ant #Carrier Manufacturer Antenna Model Az (deg)TX (MHz)RX (MHz)EDT (deg) MDT (deg) Gain (dBd)ERP (W)Rad Ctr (ft) 1 TMO Nokia AEHC 000 2496-2690 2496-2690 5 0 22.6 48994.8 75.0 2 TMO Nokia AEHC 120 2496-2690 2496-2690 5 0 22.6 48994.8 75.0 3 TMO Nokia AEHC 240 2496-2690 2496-2690 5 0 22.6 48994.8 75.0 622-640 668-686 5661.6 728-734 698-704 6806.8 1740-1765 1740-1765 7691.8 1960-1965 1880-1885 8054.3 1980-1990 1900-1910 8054.3 2140-2165 2140-2165 8831.4 622-640 668-686 5661.6 728-734 698-704 6806.8 1740-1765 1740-1765 7691.8 1960-1965 1880-1885 8054.3 1980-1990 1900-1910 8054.3 2140-2165 2140-2165 8831.4 622-640 668-686 5661.6 728-734 698-704 6806.8 1740-1765 1740-1765 7691.8 1960-1965 1880-1885 8054.3 1980-1990 1900-1910 8054.3 2140-2165 2140-2165 8831.4 7 VZW Ericsson AIR 6449 B77D/ C-Band 000 3500-3700 3500-3700 6 0 23.6 71639.1 57.0 8 VZW Ericsson AIR 6449 B77D/ C-Band 090 3500-3700 3500-3700 6 0 23.6 71639.1 57.0 9 VZW Ericsson AIR 6449 B77D/ C-Band 220 3500-3700 3500-3700 6 0 23.6 71639.1 57.0 776-787 746-757 6952.2 835-845 880-890 7279.8 846.5-849 891.5-894 7279.8 1710-1720 1945-1950 11018.5 1725-1730 1970-1975 11018.5 1735-1740 2110-2120 11537.8 1740-1745 2125-2130 11537.8 1745-1755 2135-2140 11537.8 1755-1760 2140-2145 11537.8 1760-1765 2145-2155 11537.8 1865-1870 2155-2160 11537.8 1890-1895 2160-2165 11537.8 73.0 73.0 73.0 57.00013.8 2 0 12.9 6 TMO Commscope FFVV-65C-R2N23 240 2 0 12.9 5 TMO Commscope FFVV-65C-R2N23 120 4 TMO Commscope FFVV-65C-R2N23 000 2 0 12.9 10 VZW Commscope NHHSS-65C-R2B 000 9 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 2.2 Antenna Inventory Ant #Carrier Manufacturer Antenna Model Az (deg)TX (MHz)RX (MHz)EDT (deg) MDT (deg) Gain (dBd)ERP (W)Rad Ctr (ft) 776-787 746-757 6952.2 835-845 880-890 7279.8 846.5-849 891.5-894 7279.8 1710-1720 1945-1950 11018.5 1725-1730 1970-1975 11018.5 1735-1740 2110-2120 11537.8 1740-1745 2125-2130 11537.8 1745-1755 2135-2140 11537.8 1755-1760 2140-2145 11537.8 1760-1765 2145-2155 11537.8 1865-1870 2155-2160 11537.8 1890-1895 2160-2165 11537.8 776-787 746-757 6952.2 835-845 880-890 7279.8 846.5-849 891.5-894 7279.8 1710-1720 1945-1950 11018.5 1725-1730 1970-1975 11018.5 1735-1740 2110-2120 11537.8 1740-1745 2125-2130 11537.8 1745-1755 2135-2140 11537.8 1755-1760 2140-2145 11537.8 1760-1765 2145-2155 11537.8 1865-1870 2155-2160 11537.8 1890-1895 2160-2165 11537.8 776-787 746-757 9706.4 835-845 880-890 9932.5 846.5-849 891.5-894 9932.5 1710-1720 1945-1950 12562.3 1725-1730 1970-1975 12562.3 1735-1740 2110-2120 14423.4 1740-1745 2125-2130 14423.4 1745-1755 2135-2140 14423.4 1755-1760 2140-2145 14423.4 1760-1765 2145-2155 14423.4 1865-1870 2155-2160 14423.4 1890-1895 2160-2165 14423.4 0 0 13.812VZWCommscopeNHHSS-65C-R2B 220 11 VZW Commscope NHHSS-65C-R2B 090 0 0 13.8 13 VZW Commscope NHH-65C-R2B 000 57.0 57.0 57.00013.2 10 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 2.3 Antenna Inventory Ant #Carrier Manufacturer Antenna Model Az (deg)TX (MHz)RX (MHz)EDT (deg) MDT (deg) Gain (dBd)ERP (W)Rad Ctr (ft) 776-787 746-757 9706.4 835-845 880-890 9932.5 846.5-849 891.5-894 9932.5 1710-1720 1945-1950 12562.3 1725-1730 1970-1975 12562.3 1735-1740 2110-2120 14423.4 1740-1745 2125-2130 14423.4 1745-1755 2135-2140 14423.4 1755-1760 2140-2145 14423.4 1760-1765 2145-2155 14423.4 1865-1870 2155-2160 14423.4 1890-1895 2160-2165 14423.4 776-787 746-757 9706.4 835-845 880-890 9932.5 846.5-849 891.5-894 9932.5 1710-1720 1945-1950 12562.3 1725-1730 1970-1975 12562.3 1735-1740 2110-2120 14423.4 1740-1745 2125-2130 14423.4 1745-1755 2135-2140 14423.4 1755-1760 2140-2145 14423.4 1760-1765 2145-2155 14423.4 1865-1870 2155-2160 14423.4 1890-1895 2160-2165 14423.4 0 0 13.2 57.0 57.0 0 15 VZW Commscope NHH-65C-R2B 220 14 VZW Commscope NHH-65C-R2B 090 0 13.2 11 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 3.1 MPE Limit Study General Population 12 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 3.2 MPE Limit Study Occupational Limit 13 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 3.3 MPE Limit Study General Population – Horizontal View 14 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 3.4 MPE Limit Study Occupational Limit – Horizontal View 15 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 4.1 Barrier & Sign Types Stanchion Type Cone Type A-Frame Type 16 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 4.2 Barrier & Sign Types 17 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 5 Information Pertaining to MPE Studies In 1985, the FCC first adopted guidelines to be used for evaluating human exposure to RF emissions. The FCC revised and updated these guidelines on August 1, 1996, as a result of a rule-making proceeding initiated in 1993. The new guidelines incorporate limits for Maximum Permissible Exposure (MPE) in terms of electric and magnetic field strength and power density for transmitters operating at frequencies between 300 kHz and 100 GHz. The FCC's MPE limits are based on exposure limits recommended by the National Council on Radiation Protection and Measurements (NCRP), and, over a wide range of frequencies, the exposure limits were developed by the Institute of Electrical and Electronics Engineers, Inc., (IEEE) and adopted by the American National Standards Institute (ANSI) to replace the 1982 ANSI guidelines. Limits for localized absorption are based on recommendations of both ANSI/IEEE and NCRP. The FCC's limits, and the NCRP and ANSI/IEEE limits on which they are based, are derived from exposure criteria quantified in terms of specific absorption rate (SAR). The basis for these limits is a whole-body averaged SAR threshold level of 4 watts per kilogram (4 W/kg), as averaged over the entire mass of the body, above which expert organizations have determined that potentially hazardous exposures may occur. The MPE limits are derived by incorporating safety factors that lead, in some cases, to limits that are more conservative than the limits originally adopted by the FCC in 1985. Where more conservative limits exist, they do not arise from a fundamental change in the RF safety criteria for whole-body averaged SAR, but from a precautionary desire to protect subgroups of the general population who, potentially, may be more at risk. The FCC exposure limits are also based on data showing that the human body absorbs RF energy at some frequencies more efficiently than at others. The most restrictive limits occur in the frequency range of 30-300 MHz where whole-body absorption of RF energy by human beings is most efficient. At other frequencies, whole-body absorption is less efficient, and consequently, the MPE limits are less restrictive. 18 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA MPE limits are defined in terms of power density (units of milliwatts per centimeter squared: mW/cm2), electric field strength (units of volts per meter: V/m) and magnetic field strength (units of amperes per meter: A/m). The far-field of a transmitting antenna is where the electric field vector (E), the magnetic field vector (H), and the direction of propagation can be considered to be all mutually orthogonal ("plane-wave" conditions). Occupational/controlled exposure limits apply to situations in which persons are exposed as a consequence of their employment and in which those persons who are exposed have been made fully aware of the potential for exposure and can exercise control over their exposure. Occupational/controlled exposure limits also apply where exposure is of a transient nature as a result of incidental passage through a location where exposure levels may be above general population/uncontrolled limits (see below), as long as the exposed person has been made fully aware of the potential for exposure and can exercise control over his or her exposure by leaving the area or by some other appropriate means. General population/uncontrolled exposure limits apply to situations in which the general public may be exposed or in which persons who are exposed as a consequence of their employment may not be made fully aware of the potential for exposure or cannot exercise control over their exposure. Therefore, members of the general public would always be considered under this category when exposure is not employment-related, for example, in the case of a telecommunications tower that exposes persons in a nearby residential area. Additional details can be found in FCC OET 65. 19 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Appendix 6 MPE Standards Methodology This study predicts RF field strength and power density levels that emanate from communications system antennae. It considers all transmitter power levels (less filter and line losses) delivered to each active transmitting antenna at the communications site. Calculations are performed to determine power density and MPE levels for each antenna as well as composite levels from all antennas. The calculated levels are based on where a human (Observer) would be standing at various locations at the site. The point of interest where the MPE level is predicted is based on the height of the Observer. Compliance with the FCC limits on RF emissions are determined by spatially averaging a person’s exposure over the projected area of an adult human body, that is approximately six-feet or two-meters, as defined in the ANSI/IEEE C95.1 standard. The MPE limits are specified as time-averaged exposure limits. This means that exposure is averaged over an identifiable time interval. It is 30 minutes for the general population/uncontrolled RF environment and 6 minutes for the occupational/controlled RF environment. However, in the case of the general public, time averaging should not be applied because the general public is typically not aware of RF exposure, and they do not have control of their exposure time. Therefore, it should be assumed that any RF exposure to the general public will be continuous. 20 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA The FCC’s limits for exposure at different frequencies are shown in the following Tables. Limits for Occupational/Controlled Exposure Frequency Range (MHz) Electric Field Strength (E) (V/m) Magnetic Field Strength (H) (A/m) Power Density (S) (mW/cm2) Averaging Time |E|2, |H|2 or S (minutes) 0.3 - 3.0 614 1.63 100* 6 3.0 - 30 1842/f 4.89/f 900/F2 6 30 - 300 61.4 0.163 1.0 6 300 - 1500 -- -- f/300 6 1500 - 100,000 -- -- 5 6 f = frequency * = Plane-wave equivalent power density 21 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Occupational/controlled limits apply in situations in which persons are exposed as a consequence of their employment provided those persons are fully aware of the potential for exposure and can exercise control over their exposure. Limits for occupational/controlled exposure also apply in situations when an individual is transient through a location where occupational/controlled limits apply provided he or she is made aware of the potential for exposure. f = frequency * = Plane-wave equivalent power density General population/uncontrolled exposures apply in situations in which the general public may be exposed or in which persons that are exposed as a consequence of their employment may not be fully aware of the potential for exposure or cannot exercise control over their exposure. It is important to understand that these limits apply cumulatively to all sources of RF emissions affecting a given area. For example, if several different communications Limits for General Population/Uncontrolled Exposure Frequency Range (MHz) Electric Field Strength (E) (V/m) Magnetic Field Strength (H) (A/m) Power Density (S) (mW/cm2) Averaging Time |E|2, |H|2 or S (minutes) 0.3 - 1.34 614 1.63 100* 30 1.34 - 30 824/f 2.19/f 180/F2 30 30 -300 27.5 0.073 0.2 30 300 -1500 -- -- f/1500 30 1500 -100,000 -- -- 1.0 30 22 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA system antennas occupy a shared facility such as a tower or rooftop, then the total exposure from all systems at the facility must be within compliance of the FCC guidelines. The field strength emanating from an antenna can be estimated based on the characteristics of an antenna radiating in free space. There are basically two field areas associated with a radiating antenna. When close to the antenna, the region is known as the Near Field. Within this region, the characteristics of the RF fields are very complex, and the wave front is extremely curved. As you move further from the antenna, the wave front has less curvature and becomes planar. The wave front still has a curvature, but it appears to occupy a flat plane in space (plane-wave radiation). This region is known as the Far Field. Two models are utilized to predict Near and Far field power densities. They are based on the formulae in FCC OET 65. Cylindrical Model (Near Field Predictions) Spatially averaged plane-wave equivalent power densities parallel to the antenna may be estimated by dividing the antenna input power by the surface area of an imaginary cylinder surrounding the length of the radiating antenna. While the actual power density will vary along the height of the antenna, the average value along its length will closely follow the relation given by the following equation: Where: S = Power Density P = Total Power into antenna R = Distance from the antenna L = Antenna aperture length S P RL=2 23 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA For directional-type antennas, power densities can be estimated by dividing the input power by that portion of a cylindrical surface area corresponding to the angular beam width of the antenna. For example, for the case of a 120-degree azimuthal beam width, the surface area should correspond to 1/3 that of a full cylinder. This would increase the power density near the antenna by a factor of three over that for a purely omni-directional antenna. Mathematically, this can be represented by the following formula: Where: S = Power Density θBW = Beam width of antenna in degrees (3 dB half-power point) P = Total Power into antenna R = Distance from the antenna L = Antenna aperture length If the antenna is a 360-degree omni-directional antenna, this formula would be equivalent to the previous formula. ()S P RLBW=180 / 24 Site Number: 419657 Site Name: Bridger View MT, Bozeman, MT , CA Spherical Model (Far Field Predictions) Spatially averaged plane-wave power densities in the Far Field of an antenna may be estimated by considering the additional factors of antenna gain and reflective waves that would contribute to exposure. The radiation pattern of an antenna has developed in the Far Field region and the power gain needs to be considered in exposure predictions. Also, if the vertical radiation pattern of the antenna is considered, the exposure predictions would most likely be reduced significantly at ground level, resulting in a more realistic estimate of the actual exposure levels. Additionally, to model a truly "worst case" prediction of exposure levels at or near a surface, such as at ground-level or on a rooftop, reflection off the surface of antenna radiation power can be assumed, resulting in a potential four-fold increase in power density. These additional factors are considered, and the Far Field prediction model is determined by the following equation: Where: S = Power Density EIRP = Effective Radiated Power from antenna Rc = Reflection Coefficient (2.56) R = Distance from the antenna The EIRP includes the antenna gain. If the antenna pattern is considered, the antenna gain is relative based on the horizontal and vertical pattern gain values at that particular location in space, on a rooftop or on the ground. However, it is recommended that the antenna radiation pattern characteristics not be considered to provide a conservative "worst case" prediction. This is the equation is utilized for the Far Field exposure predictions herein. S EIRP Rc R=4 2