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2020.0259.PR0008 NIER_Report_TCOMM911_Yelm_Water_Tank_08282020 Final Report NIER Calculations TCOMM Yelm Water Tank Site Prepared for Rich Hall Land Development Consultants Prepared by Tom Manley ADCOMM Engineering Company Reviewed by Joe Blaschka, Jr. PE ADCOMM Engineering Company Date Prepared July 30, 2020 ADCOMM ENGINEERING COMPANY | COMMUNICATIONS CONSULTING Page iii Contents Contents ......................................................................................................................................... iii Acronyms and Abbreviations ........................................................................................................ iv Summary ......................................................................................................................................... 5 Regulatory Background .................................................................................................................. 7 Calculations..................................................................................................................................... 9 Evaluation ....................................................................................................................................... 9 ADCOMM ENGINEERING COMPANY | COMMUNICATIONS CONSULTING Page iv Acronyms and Abbreviations AGL above ground level ERP effective radiated power EIRP Equivalent Isotropically Radiated Power FCC Federal Communications Commission MPE maximum permissible exposure MW microwave RF radio frequency Page 5 Summary Calculations and measurements were done for a TCOMM radio site planned for a City of Yelm water tank at 901 NW Rhoton Rd, Yelm, WA (see Figure 1). The site will host 800 MHz radio equipment, VHF radios, and two MW antennas for connection to other sites. Figure 1- Water Tank Site Existing RF equipment was shown on the construction drawings provided so measurements were planned and performed. However, no equipment was observed on the water tank itself at the time of the site visit. There was unidentified radio equipment (a vertical antenna and a MW dish) noted on the roof of the Yelm Public Works building approximately 250-ft to the Northwest of the water tank (see Figures 2 and 3). Figure 2- Location of existing radio equipment Page 6 Figure 3- Adjacent radio equipment Measurements were conducted in the vicinity of the water tank and radio equipment as well as adjacent residential areas. Measured values representing the percentage of MPE for a General Population/Uncontrolled Exposure area are shown in Figure 4. Measurements were performed with a Narda NBM-550 Broadband Field Strength Meter equipped with a 300kHz-50GHz Shaped Isotropic Probe. Figure 4- Measured power density levels Page 7 The measurements found a maximum exposure of 10.155% of the MPE for a General Population/Uncontrolled Exposure area. Calculations indicate a maximum additional exposure at 375-ft from the base of the tank of 1.5102% of the MPE for General Population/Uncontrolled Exposure. The site meets the FCC requirements for General Population/Uncontrolled Exposure at ground- level. Regulatory Background The procedures for calculating the RF power densities are taken from “Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields, OET Bulletin 65, August 1997.” FCC Rules and Regulations further describe requirements for compliance in CFR 47 §1.1310, “Radiofrequency Radiation Exposure Limits.” The formula used for calculation is Equation 9 of OET65 on page 21: 2 4.33 R ERPS= Where: S= power density in µW/cm2 ERP= power in watts R= distance in meters Where this equation is applied in a spreadsheet, the vertical attenuation pattern of the antenna is taken into account. The FCC limits for maximum permissible exposure (MPE) are shown graphically in Figure 2 and in tabular form in Table 2. The exposure limit differs depending on frequency due to the variable rate of RF absorption of the human body at different frequencies. 100 10 1 0.1 0.03 0.3 3 30 300 30,0003,000 1,000 0.2 5 Occupational/Controlled Exposure 300,000 General Population/Uncontrolled Exposure 100,0001.34 1,500 FCC Limits for Maximum Permissible Exposure (MPE) Plane-wave Equivalent Power Density Frequency (MHz) Page 8 Figure 2. FCC Limits for MPE Although the label “radiation” is often used in this situation, a distinction is made between ionizing radiation and non-ionizing radiation such as RF. Ionizing radiation is so energetic that it literally breaks electrons away from atoms creating an ion. Electromagnetic radiation is only capable of this at frequencies of 1015 Hz, 106 GHz, or higher. This is the realm of some UV light, X-rays, gamma rays, cosmic rays, and particles produced in radioactive decay. The frequencies of interest here are well below those of ionizing radiation, well within the RF spectrum, and universally recognized as non-ionizing electromagnetic radiation (NIER). The effects of NIER are thermal. The energy impinging on the human body causes heat to be generated in body tissue. The effect of this heating has biological effects above certain power levels. The curve above for general population/uncontrolled exposure is typically 2 percent of the level at which thermal effects begin to be seen. The antennas typically used in the service found at this site are directional so that most of the RF energy emitted by the antennas is concentrated in a limited field of view. In particular, energy is usually directed toward the horizon with appreciable attenuation below the antenna. Table 2 (A) Limits for Occupational/Controlled Exposure ______________________________________________________________________________ Frequency Electric Field Magnetic Field Power Density Averaging Time Range Strength (E) Strength (H) (S) |E|2, |H|2 or S (MHz) (V/m) (A/m) (mW/cm2) (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 ______________________________________________________________________________ (B) Limits for General Population/Uncontrolled Exposure ______________________________________________________________________________ Frequency Electric Field Magnetic Field Power Density Averaging Time Range Strength (E) Strength (H) (S) |E|2, |H|2 or S (MHz) (V/m) (A/m) (mW/cm2) (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 Page 9 1500-100,000 -- -- 1.0 30 ______________________________________________________________________________ f = frequency in MHz *Plane-wave equivalent power density NOTE 1: 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. NOTE 2: 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. Calculations The proposed antennas include an RFI Wireless Model CC807-06 Collinear Antenna, two 4-ft 11 GHz MW antennas, a 4-bay Bird BA-80 VHF folded dipole used as two 2-bay folded dipoles. Specific model numbers were not provided for the MW antennas or the folded dipole so standard performance MW dishes , with slightly less directivity than high performance dishes that are pictorially shown on drawings were used for analysis. Likewise, EIRP values were not provided so the maximum power expected for each antenna was used. These measures ensure that the exposure calculated represents a worst-case scenario for evaluation. In formation for the analysis was taken from the drawings LDC-Pyramid TCOMM911 Yelm Water Tank PZD Rev 5 and 20200612 LDC-Pyramid Tracker TCOMM911.xlsx. In addition, information on the VHF antennas was provided in an email from Richard Hall, titled TCOMM911 Yelm VHF Antenna Data, dated July 29, 2020. The calculations are included in the Attachment section. A composite spreadsheet shows the cumulative exposure at the ground-level. Note that the heights used represent the center-of- radiation for each antenna and also account for a head-height of 6-ft. Evaluation The maximum exposure value measured at the site was 10.155% of the MPE for a General Population/Uncontrolled Exposure area. The maximum calculated %MPE on the ground occurs at a distance of 375-ft from the base of the building with a level that is 1.5102% of the FCC MPE for an uncontrolled area. The site meets the FCC requirements for General Population/Uncontrolled Exposure at ground level. Page 10 Attachments Calculation spreadsheets Page 11 30-Jul-20 ADCOMM Engineering Company Non-Ionizing Electromagnetic Radiation Calculations Site: TCOMM Yelm Freq(MHz): XMT(dBm):N/A Ant. Gain:N/A Ant. Model: Composite XMT(Watts):N/A Ant. C.L. (ft):N/A MPE:N/A ERP(Watts):N/A Trans Loss:N/A Client: 25 0.2395 0.0756 0.0007 0.000204 0.3160 50 0.5589 0.1400 0.0105 0.000293 0.7097 75 0.6296 0.0791 0.1178 0.000504 0.8270 100 0.5485 0.0274 0.1626 0.000532 0.7390 125 0.2972 0.0470 0.0881 0.000697 0.4330 150 0.0401 0.1266 0.0299 0.000725 0.1973 175 0.0858 0.1078 0.0639 0.000757 0.2582 200 0.1840 0.0731 0.0137 0.000797 0.2716 225 0.4991 0.0198 0.0235 0.001064 0.5434 250 0.6821 0.0541 0.0403 0.000905 0.7774 275 0.9389 0.0937 0.0350 0.000777 1.0683 300 1.0330 0.1297 0.0386 0.000673 1.2019 325 1.1437 0.1141 0.0269 0.000739 1.2854 350 1.2741 0.0802 0.0238 0.000818 1.3789 375 1.4273 0.0714 0.0106 0.000911 1.5102 400 1.2771 0.0639 0.0095 0.001286 1.3518 425 1.1484 0.0456 0.0027 0.001152 1.1979 450 1.3065 0.0327 0.0077 0.001306 1.3483 475 1.1855 0.0236 0.0070 0.001181 1.2173 500 1.2115 0.0341 0.0202 0.001074 1.2668 525 1.2432 0.0197 0.0185 0.001233 1.2825 550 1.1409 0.0718 0.0170 0.001129 1.2308 575 1.0505 0.0661 0.0247 0.001038 1.1424 600 0.9700 0.0769 0.0288 0.001205 1.0769 625 0.8985 0.0712 0.0266 0.001114 0.9974 650 0.9361 0.0661 0.0311 0.001301 1.0347 675 0.8713 0.0615 0.0290 0.001210 0.9631 700 0.8130 0.1442 0.0340 0.001128 0.9924 725 0.7604 0.1349 0.0318 0.001327 0.9285 750 0.7127 0.1264 0.0298 0.001242 0.8702 775 0.7509 0.1495 0.0353 0.001166 0.9368 800 0.7062 0.1406 0.0332 0.001096 0.8811 825 0.6656 0.1325 0.0313 0.001032 0.8304 850 0.6282 0.1251 0.0372 0.000973 0.7914 875 0.5939 0.1182 0.0351 0.001158 0.7484 900 0.5624 0.1119 0.0333 0.001096 0.7087 925 0.5331 0.1061 0.0315 0.001039 0.6718 950 0.5061 0.1268 0.0377 0.000986 0.6716 975 0.4812 0.1206 0.0358 0.000937 0.6386 1000 0.4580 0.1148 0.0341 0.001122 0.6080 1025 0.4364 0.1093 0.0325 0.001069 0.5793 1050 0.4671 0.1313 0.0310 0.001019 0.6304 1075 0.4461 0.1254 0.0296 0.000973 0.6021 1100 0.4264 0.1199 0.0283 0.000930 0.5755 11 GHz MW800 MHz Two 2-bay folded dipoles (VHF) Center-line distance from antenna (ft) Composite On- ground %MPE Land Development Consultants VHF (PD220) Page 12 30-Jul-20 ADCOMM Engineering Company Non-Ionizing Electromagnetic Radiation Calculations Site: TCOMM Yelm Freq(MHz):VHF XMT(dBm):N/A Ant. Gain:N/A Ant. Model: Celwave PD 220 XMT(Watts):N/A Ant. C.L. (ft):155 MPE:200 uW/cm2 EIRP(Watts):1640 Trans Loss:N/A Comment: Client: 25 157 0.89741 81 22 0.000151 0.0756 50 163 0.22435 72 19 0.000280 0.1400 75 172 0.09971 64 21 0.000158 0.0791 100 185 0.05609 57 25 0.000055 0.0274 125 199 0.03590 51 22 0.000094 0.0470 150 216 0.02493 46 17 0.000253 0.1266 175 234 0.01831 42 17 0.000216 0.1078 200 253 0.01402 38 18 0.000146 0.0731 225 273 0.01108 35 23 0.000040 0.0198 250 294 0.00897 32 18 0.000108 0.0541 275 316 0.00742 29 15 0.000187 0.0937 300 338 0.00623 27 13 0.000259 0.1297 325 360 0.00531 25 13 0.000228 0.1141 350 383 0.00458 24 14 0.000160 0.0802 375 406 0.00399 22 14 0.000143 0.0714 400 429 0.00351 21 14 0.000128 0.0639 425 452 0.00311 20 15 0.000091 0.0456 450 476 0.00277 19 16 0.000065 0.0327 475 500 0.00249 18 17 0.000047 0.0236 500 524 0.00224 17 15 0.000068 0.0341 525 547 0.00203 16 17 0.000039 0.0197 550 571 0.00185 16 11 0.000144 0.0718 575 596 0.00170 15 11 0.000132 0.0661 600 620 0.00156 14 10 0.000154 0.0769 625 644 0.00144 14 10 0.000142 0.0712 650 668 0.00133 13 10 0.000132 0.0661 675 693 0.00123 13 10 0.000123 0.0615 700 717 0.00114 12 6 0.000288 0.1442 725 741 0.00107 12 6 0.000270 0.1349 750 766 0.00100 12 6 0.000253 0.1264 775 790 0.00093 11 5 0.000299 0.1495 800 815 0.00088 11 5 0.000281 0.1406 825 839 0.00082 11 5 0.000265 0.1325 850 864 0.00078 10 5 0.000250 0.1251 875 889 0.00073 10 5 0.000236 0.1182 900 913 0.00069 10 5 0.000224 0.1119 925 938 0.00066 10 5 0.000212 0.1061 950 963 0.00062 9 4 0.000254 0.1268 975 987 0.00059 9 4 0.000241 0.1206 1000 1012 0.00056 9 4 0.000230 0.1148 1025 1037 0.00053 9 4 0.000219 0.1093 1050 1061 0.00051 8 3 0.000263 0.1313 1075 1086 0.00049 8 3 0.000251 0.1254 1100 1111 0.00046 8 3 0.000240 0.1199 Pattern angle from antenna Centerline signal level (mW/cm2) Path length (ft) Center-line distance from antenna (ft) Power level worst-case Land Development Consultants On-ground %MPE On-ground signal level (mW/cm2) Pattern attenuation (dB) Page 13 30-Jul-20 ADCOMM Engineering Company Non-Ionizing Electromagnetic Radiation Calculations Site: TCOMM Yelm Freq(MHz):VHF XMT(dBm):N/A Ant. Gain:N/A Ant. Model: Two 2-bay Folded Dipoles (Bird BA-40) XMT(Watts):N/A Ant. C.L. (ft):155 MPE:200 uW/cm2 EIRP(Watts):3280 Trans Loss:N/A Comment: Client: 25 157 1.79482 81 20 0.000479 0.2395 50 163 0.44870 72 16 0.001118 0.5589 75 172 0.19942 64 15 0.001259 0.6296 100 185 0.11218 57 15 0.001097 0.5485 125 199 0.07179 51 17 0.000594 0.2972 150 216 0.04986 46 25 0.000080 0.0401 175 234 0.03663 42 21 0.000172 0.0858 200 253 0.02804 38 17 0.000368 0.1840 225 273 0.02216 35 12 0.000998 0.4991 250 294 0.01795 32 10 0.001364 0.6821 275 316 0.01483 29 8 0.001878 0.9389 300 338 0.01246 27 7 0.002066 1.0330 325 360 0.01062 25 6 0.002287 1.1437 350 383 0.00916 24 5 0.002548 1.2741 375 406 0.00798 22 4 0.002855 1.4273 400 429 0.00701 21 4 0.002554 1.2771 425 452 0.00621 20 4 0.002297 1.1484 450 476 0.00554 19 3 0.002613 1.3065 475 500 0.00497 18 3 0.002371 1.1855 500 524 0.00449 17 2.5 0.002423 1.2115 525 547 0.00407 16 2 0.002486 1.2432 550 571 0.00371 16 2 0.002282 1.1409 575 596 0.00339 15 2 0.002101 1.0505 600 620 0.00312 14 2 0.001940 0.9700 625 644 0.00287 14 2 0.001797 0.8985 650 668 0.00266 13 1.5 0.001872 0.9361 675 693 0.00246 13 1.5 0.001743 0.8713 700 717 0.00229 12 1.5 0.001626 0.8130 725 741 0.00213 12 1.5 0.001521 0.7604 750 766 0.00199 12 1.5 0.001425 0.7127 775 790 0.00187 11 1 0.001502 0.7509 800 815 0.00175 11 1 0.001412 0.7062 825 839 0.00165 11 1 0.001331 0.6656 850 864 0.00155 10 1 0.001256 0.6282 875 889 0.00147 10 1 0.001188 0.5939 900 913 0.00138 10 1 0.001125 0.5624 925 938 0.00131 10 1 0.001066 0.5331 950 963 0.00124 9 1 0.001012 0.5061 975 987 0.00118 9 1 0.000962 0.4812 1000 1012 0.00112 9 1 0.000916 0.4580 1025 1037 0.00107 9 1 0.000873 0.4364 1050 1061 0.00102 8 0.5 0.000934 0.4671 1075 1086 0.00097 8 0.5 0.000892 0.4461 1100 1111 0.00093 8 0.5 0.000853 0.4264 Power level worst-case Land Development Consultants On-ground %MPE On-ground signal level (mW/cm2) Pattern attenuation (dB) Pattern angle from antenna Centerline signal level (mW/cm2) Path length (ft) Center-line distance from antenna (ft) Page 14 30-Jul-20 ADCOMM Engineering Company Non-Ionizing Electromagnetic Radiation Calculations Site:TCOMM Yelm Freq(MHz):800 MHz XMT(dBm):N/A Ant. Gain:N/A Ant. Model: RFI CC807-06 XMT(Watts):N/A Ant. C.L. (ft):155 MPE:533 uW/cm2 EIRP(Watts):820 Trans Loss:N/A Comment: Client: 25 157 0.44870 81 35 0.000004 0.0007 50 163 0.11218 72 23 0.000056 0.0105 75 172 0.04986 64 12 0.000628 0.1178 100 185 0.02804 57 10 0.000867 0.1626 125 199 0.01795 51 12 0.000470 0.0881 150 216 0.01246 46 16 0.000159 0.0299 175 234 0.00916 42 12 0.000341 0.0639 200 253 0.00701 38 18 0.000073 0.0137 225 273 0.00554 35 15 0.000125 0.0235 250 294 0.00449 32 12 0.000215 0.0403 275 316 0.00371 29 12 0.000187 0.0350 300 338 0.00312 27 11 0.000206 0.0386 325 360 0.00266 25 12 0.000144 0.0269 350 383 0.00229 24 12 0.000127 0.0238 375 406 0.00199 22 15 0.000057 0.0106 400 429 0.00175 21 15 0.000051 0.0095 425 452 0.00155 20 20 0.000014 0.0027 450 476 0.00138 19 15 0.000041 0.0077 475 500 0.00124 18 15 0.000037 0.0070 500 524 0.00112 17 10 0.000108 0.0202 525 547 0.00102 16 10 0.000099 0.0185 550 571 0.00093 16 10 0.000090 0.0170 575 596 0.00085 15 8 0.000132 0.0247 600 620 0.00078 14 7 0.000153 0.0288 625 644 0.00072 14 7 0.000142 0.0266 650 668 0.00066 13 6 0.000166 0.0311 675 693 0.00062 13 6 0.000155 0.0290 700 717 0.00057 12 5 0.000182 0.0340 725 741 0.00053 12 5 0.000170 0.0318 750 766 0.00050 12 5 0.000159 0.0298 775 790 0.00047 11 4 0.000188 0.0353 800 815 0.00044 11 4 0.000177 0.0332 825 839 0.00041 11 4 0.000167 0.0313 850 864 0.00039 10 3 0.000198 0.0372 875 889 0.00037 10 3 0.000187 0.0351 900 913 0.00035 10 3 0.000177 0.0333 925 938 0.00033 10 3 0.000168 0.0315 950 963 0.00031 9 2 0.000201 0.0377 975 987 0.00030 9 2 0.000191 0.0358 1000 1012 0.00028 9 2 0.000182 0.0341 1025 1037 0.00027 9 2 0.000173 0.0325 1050 1061 0.00025 8 2 0.000165 0.0310 1075 1086 0.00024 8 2 0.000158 0.0296 1100 1111 0.00023 8 2 0.000151 0.0283 Pattern angle from antenna Centerline signal level (mW/cm2) Path length (ft) Center-line distance from antenna (ft) Power level worst-case Land Development Consultants On-ground %MPE On-ground signal level (mW/cm2) Pattern attenuation (dB) Page 15 30-Jul-20 ADCOMM Engineering Company Non-Ionizing Electromagnetic Radiation Calculations Site: TCOMM Yelm Freq(MHz):11 GHz XMT(dBm):N/A Ant. Gain:N/A Ant. Model: 4-ft 11 GHz SP XMT(Watts):N/A Ant. C.L. (ft):130.5 MPE:1000uW/cm2 EIRP(Watts):20000 Trans Loss:N/A Comment: Client: 25 133 10.94400 79 53 0.000002 0.000204 50 140 2.73600 69 51 0.000003 0.000293 75 151 1.21600 60 48 0.000005 0.000504 100 164 0.68400 53 47 0.000005 0.000532 125 181 0.43776 46 45 0.000007 0.000697 150 199 0.30400 41 44 0.000007 0.000725 175 218 0.22335 37 43 0.000008 0.000757 200 239 0.17100 33 42 0.000008 0.000797 225 260 0.13511 30 40 0.000011 0.001064 250 282 0.10944 28 40 0.000009 0.000905 275 304 0.09045 25 40 0.000008 0.000777 300 327 0.07600 24 40 0.000007 0.000673 325 350 0.06476 22 39 0.000007 0.000739 350 374 0.05584 20 38 0.000008 0.000818 375 397 0.04864 19 37 0.000009 0.000911 400 421 0.04275 18 35 0.000013 0.001286 425 445 0.03787 17 35 0.000012 0.001152 450 469 0.03378 16 34 0.000013 0.001306 475 493 0.03032 15 34 0.000012 0.001181 500 517 0.02736 15 34 0.000011 0.001074 525 541 0.02482 14 33 0.000012 0.001233 550 565 0.02261 13 33 0.000011 0.001129 575 590 0.02069 13 33 0.000010 0.001038 600 614 0.01900 12 32 0.000012 0.001205 625 639 0.01751 12 32 0.000011 0.001114 650 663 0.01619 11 31 0.000013 0.001301 675 688 0.01501 11 31 0.000012 0.001210 700 712 0.01396 11 31 0.000011 0.001128 725 737 0.01301 10 30 0.000013 0.001327 750 761 0.01216 10 30 0.000012 0.001242 775 786 0.01139 10 30 0.000012 0.001166 800 811 0.01069 9 30 0.000011 0.001096 825 835 0.01005 9 30 0.000010 0.001032 850 860 0.00947 9 30 0.000010 0.000973 875 885 0.00893 8 29 0.000012 0.001158 900 909 0.00844 8 29 0.000011 0.001096 925 934 0.00799 8 29 0.000010 0.001039 950 959 0.00758 8 29 0.000010 0.000986 975 984 0.00720 8 29 0.000009 0.000937 1000 1009 0.00684 7 28 0.000011 0.001122 1025 1033 0.00651 7 28 0.000011 0.001069 1050 1058 0.00620 7 28 0.000010 0.001019 1075 1083 0.00592 7 28 0.000010 0.000973 1100 1108 0.00565 7 28 0.000009 0.000930 Pattern angle from antenna Centerline signal level (mW/cm2) Path length (ft) Center-line distance from antenna (ft) Land Development Consultants On-ground %MPE On-ground signal level (mW/cm2) Pattern attenuation (dB)