An analysis of siting criteria for the KRPI 5-tower array

BBC Broadcasting, Inc. (BBC) which operates a radio station KRPI 1550 AM out of Ferndale (12), WA has applied to Whatcom County Planning and Development Services (PDS) for a Conditional Use Permit (CUP) to erect an array of five broadcasting towers on a 10 acre lot roughly 950 feet from the Canadian border. The FCC has approved the relocation of the array and pre-approved a construction permit for KRPI to broadcast at 50,000 Watts both day and night from Point Roberts, WA. This analysis reviews the impact of the cross border blanketing interference on Tsawwassen, BC.
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  2014-10-15 10:53 AM Page 1  of 21   An analysis of siting criteria for the KRPI 5-tower array Prepared by Jim Ronback, System Safety Engineer, Ret. 1530 Kirkwood Road Tsawwassen, BC, Canada V4L 1G1 Introduction BBC Broadcasting, Inc. (BBC) which operates a radio station KRPI 1550 AM out of Ferndale (12), WA has applied to Whatcom County Planning and Development Services (PDS) for a Conditional Use Permit (CUP) to erect an array of five broadcasting towers on a 10 acre lot roughly 950 feet from the Canadian border. The FCC has approved the relocation of the array and pre-approved a construction permit for KRPI to broadcast at 50,000 Watts both day and night. AM signals of this strength are known to produce harmful “blanketing interference” within an electric field of 1 Volt per meter contour around the towers. In their CUP application, BBC, Inc., and Hatfield & Dawson (H&D), an engineering consulting firm recruited by BBC, take note of this problem. They acknowledge problems with electronic equipment, phones, computers and other communication systems that are likely to occur and discuss the need for mitigation. They estimate the number of residents in Point Roberts who will be affected as 111 during the nighttime and 304 at daytime. As will become clear, this is a vast underestimate of the actual number when the population of Tsawwassen, BC, Canada which lies immediately north of the border is taken into account. In fact, some 20,000 (by the 2006 census; current estimate is approximately 21,000) residents live within the 4.5 km (2.8 mi) 1  wide blanketing interference contour. Figure 1 below takes the H&D map and overlays it on a Google map of Tsawwassen, BC and shows the full daytime and nighttime contours. Because of these blanketing interference problems affecting nearby populations, whenever possible, powerful AM broadcasting towers are located in remote rural sites or mountain tops – not highly populated areas. Blanketing interference from high power AM broadcast towers can result in an excessive wide spectrum of radio frequency (RF) energy due to harmonics that can cause coupling of RF noise in various frequency bands into conductors such as power lines, unshielded speaker wires, unshielded power cords, cordless phones, poorly shielded RF amplifiers in AM and FM radio and TV tuners and antennas. They can also compromise the functions of public address systems, HAM radio operations, baby and invalid-patient monitors, robots, emergency radio services and other electronic devices. For the public living or working near an antenna tower, the issues of the potential for negative impact upon property values and the potential for negative health effects are their greatest concerns related to antenna installations. (88) For over a decade, the residents in Ferndale have complained 2  to the Federal Communications Commission (FCC) about just such harmful RF blanketing interference. The problem has become so acute that H&D, in their report to BBC Broadcasting, described the city as a “poisoned well.” H&D was retained by BBC to find a place to relocate. They had several criteria in mind (see the position paper “Omissions and misrepresentations”), but ultimately 1 KRPI directional antenna pattern for Point Roberts showing 1Volt/meter contours  2   Ferndale Complaints ,    2014-10-15 10:53 AM Page 2  of 21  identified Point Roberts as optimal. In their CUP application and in their application to the FCC for approval to relocate, H&D identify only a small portion of the 1,300 residents of Point Roberts as being within the scope of the anticipated harmful blanketing interference. There was no mention made of those living in densely populated Tsawwassen. These circumstances produce a problem that is, literally, of international proportions. There are treaties in place that require cooperation and clearance when telecommunication and broadcast signals cross borders, specifically the 1984 Ottawa Agreement and the International Telecommunications Union (ITU). There are also guidelines that establish maximums for electromagnetic RF blanketing interference (10) have been set by both the FCC (2) in the United States and Canada’s Industry Canada (IC). IC’s radio tower site selection population rule C-10.3.1(c) 3  and the FCC codes contained in ¶73.24, ¶73.37 and ¶73.1650 (all revised in 2012) outline international guidelines and maximum population densities within affected areas. In addition, the ITU, which both the US and Canada are signatory to, states in Article 0.4 (3): “All stations, whatever their purpose, must be established and operated in such a manner as not to cause harmful interference to the radio services or communications of other Members or of recognized operating agencies, or of other duly authorized operating agencies which carry on a radio service, and which operate in accordance with the provisions of these Regulations (No. 197 of the Constitution).”(79) In the following analyses it is shown that when the full blanketing interference contours are examined without being truncated by the border between the US and Canada, they encompass a population with patterns of relative high density that violate the guidelines of the FCC and IC as well as the spirit of the ITU. An examination of the H&D report and the BBC Broadcasting applications It is worth asking why the initial application failed to trigger off alarm bells at IC and the FCC. Industry Canada was notified of the “minor” change that was requested and signed off on it in 2012. But none of the issues raised above were considered, only the question of whether there were AM stations in the vicinity whose signals might be compromised by adjacent channel interference by moving to Point Roberts and boosting nighttime broadcasting power to 50,000 watts from 10,000 watts. It seems fairly clear that BBC deliberately ignored the dense population in Tsawwassen which is part of the Corporation of Delta. It cannot be that they were unaware. The KRPI studios are in Richmond, BC just north of Delta. Their main offices are located there as well. Their stated target audience is in British Columbia’s lower mainland including Metro Vancouver. Their revenue stream is wholly (or nearly so) Canadian. It can only be that by failing to recognize the 21,000 plus residents of Tsawwassen none of the issues pointed out here needed to be taken into consideration by the FCC. Sometimes omissions are neutral. Sometimes they are simple mistakes. Sometimes they are motivated. 3  Part 2: Application Procedures and Rules for AM Broadcasting Undertakings BPR-2 Issue 2 January 2009$file/bpr2-rpr2-v2-jan2009-eng.pdf    2014-10-15 10:53 AM Page 3  of 21  Figure 1: RF Blanketing Interference contours of 1 V/m extended into Canada.  2014-10-15 10:53 AM Page 4  of 21  H&D’s report provided RF electric field strength maps in their site selection engineering report. It shows only the truncated daytime and nighttime RF blanketing interference contours of 1 V/m, omitting any details of the dense population data for Tsawwassen, BC. By providing this incomplete map on their relocation application they circumvented the need to comply with the FCC and IC site selection population regulations. To understand how this came about consider that the FCC’s ¶73.24 (g) specifies that an applicant must show that “the population within the 1 V/m contour does not exceed 1.0 percent of the population within the 25 mV/m contour…. provided, however, that where the number of persons within the 1 V/m is 300 or less the provisions of this paragraph are not applicable.” That “however” above stipulates that the minimum population within the 25 mV/m contour must be more than 30,100, of which 1% allows a population of 301 or more to be within the daytime blanketing interference contour of 1 V/m. The application BBC filed with the FCC set the nighttime and daytime populations within the 1 V/m blanketing interference contours at 111 and 304 respectively within Point Roberts only. If the daytime number is less than 300, KRPI can claim that rule 73.24(g) is not applicable during the daytime. The nighttime population of 111 means that the population within the 25 mV/m contour must exceed 11,100 south of the border. While the presented contour in the Radio-Locator map has an “open,” and hence ambiguous, segment to the south, it is highly unlikely that the population within it reaches the threshold as there are no cities within it other than Friday Harbor with a population of some 2,200. To circumvent this problem, BBC asked for and obtained a waiver on the grounds that the 304 persons within the daytime 1 V/m is barely above the cut-off of 300 persons within the blanketing interference contour. Of course, 304 is the number living within it in Point Roberts . Unless someone at the FCC who was reviewing this application knew that thousands of homes, schools, churches and businesses were directly to the north of the planned tower array across the border, there would be no reason not to grant it. It’s also worth noting the language of Industry Canada’s clause C-10.3.1 which expresses similar considerations. It states that “…the population within the day or night 1 V/m contour should be less than 0.02% of the population within the 5 mV/m contour.” There are reasons why these guidelines are expressed in this fashion. Radio waves spread like the diminishing waves in a pond when a rock is thrown into it. The strength of the signal along the radial varies as the inverse of the square root of the radius, i.e., Sqrt(1/radius). Thus the likelihood of harmful blanketing interference depends upon the distance from the source. It may require adjustments taken for geological factors such as, conductivity over land and water, terrain height, signal strength and time of day. For example, that map in Figure 1 shows that the maximum northwest radial for the nighttime 1 V/m contour is about 4.5 Km (2.8 miles). The northwest lobe of the nighttime blanketing interference contour encompasses most of Tsawwassen, including the most densely populated area. The guidelines are established so that the proportion of the population within the reach of the radio signal that will suffer harmful blanketing interference is kept at a minimum. As noted above, this is why in high-density areas efforts are made to locate broadcasting towers on the outskirts, away from neighborhoods with high population densities. The analyses that follow show that when the residents of Tsawwassen, BC are brought into the calculations the tower array slated for Point Roberts violates the guidelines of the FCC, IC and the ITU. Using the ratio of signal strengths, the estimated nighttime “local listening” 2.5 mV/m (red) contour maximum radial is {Sqrt(1000/2.5) = 20} * 4.5 = 90 km (56 miles) approximately (see Figures 2 and 4 below). Thus the nighttime maximum radial for FCC’s 25 mV/m population rule is ([Sqrt(1000/ 25)] = 6.32) * 4.5 = 28.5 km (17.7 miles) approximately. In Figure 4 the proximate Industry Canada 5 mV/m nighttime contour is shown. Its maximum
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