Friday, October 7, 2005
Wireless bylaw revision gets underway
There are still no cell towers in Carlisle, but they are coming. Last Thursday evening, Wireless Bylaw Committee members Rich Boule, Brian Larson, John Williams (representing the Selectmen) and Wendell Sykes (representing the School Committee) met in the Clark Room to try to clarify Carlisle's position on cell towers and other structures needed to support wireless services here, as required by the Telecommunications Act of 1996. Also present was Paul McCormack of School Street. To assist the committee in this process was David Maxson, managing partner of Broadcast Signal Lab of Medfield.
Town stands 0 for 4
The Planning Board originally commissioned Broadcast Signal Lab in 2003 to discover and analyze possible sites in Carlisle on which to locate wireless service facilities with the least impact on the community. Broadcast Signal Lab's report recommended the construction of at least four cell towers in Carlisle ("Consultants recommend four cell towers for Carlisle," June 20, 2003). In addition to the one to be built on Bedford Road, the town must identify other sites in order to complete the required coverage.
The Selectmen have urged a deadline of June 2006 for identifying a site in the center of town. Questions still remain relating to safety and aesthetic issues as well as to the Town Bylaw requiring a 900-foot setback for all wireless structures. The courts have determined the bylaw to be overly restrictive. Carlisle must find a way to change it while taking into consideration the environmental concerns of the townspeople.
During the course of the meeting, Maxson fielded questions from the committee and McCormack in an attempt to explain the best current knowledge about wireless facilities and the specific needs of the Carlisle community.
Safety is still a labyrinthine issue
The Federal Communications Commission (FCC) has established safety standards, said Maxson, "based on the science of how radio waves [energy] interact with human physiology. If the magnitude of the energy can be sensed, the energy is increasing faster than we have the ability to disperse it." FCC standards locate the acceptable measure of magnitude far below this point. "You would have to have 3,000 Verizon antennae on your tower to come close to 'sensing,'" said Maxson.
Maxson did not answer directly, "It depends upon the surface area of the antenna, how much the antenna is transmitting, and other factors." Henoted that an exact measure of radiation exposure is difficult because of factors like topography, trees, and buildings in the area.
"If you trust the government standards for licensees of your towers," he said, "it doesn't matter where you stand because the maximum standard is so low. The FCC gives guidelines on how to figure standards and administer them, as well. If the facility meets federal criteria it will fall well below the maximum limit and will not need a routine evaluation." An evaluation may be necessary if the facility sets off or causes intereference with other electronic devices, like radar detectors. If an evaluation is required, Maxson explained, "Each party [licensee] must make sure that its power contribution does not exceed 75% of the safety limit. Any or all parties shown to be exceeding this limit must mitigate the contribution until the total output comes within bounds. It all comes down to whether or not you trust the FCC standards."
Paul McCormack argued that there are presently too many unknowns about the effects of radio waves on human beings, and that we have no long-term studies to indicate what they might be. He said that more than magnitude must be measured. Echoing the community's concerns about locating a wireless facility at Carlisle Public School, he said, "During the day, the school is the most densely populated area in the town." He added that it would be valuable to know when during the day the peak level of power usage would fall as well.
Identifying the overlay district
Maxson responded that there are several ways to identify a "wireless overlay district." To bypass the 900-foot setback restriction, it might be possible to set separate standards for a defined overlay district, which may include non-contiguous sites. "The uniqueness of the community will dictate an overlay district that will work for Carlisle," he said. Then it would be necessary to consider zoning, terrain, tree density, and other factors for effective distribution of facilities.
A low-power alternative to cell towers
Noting the discomfort with siting a tower on school property, he suggested exploring the idea of a "distributed antenna system," which involves siting a base station "hotel" on town property, running fiber optic cables down the power lines and hanging "electronic cabinets" on the telephone poles. Small antennae would be affixed to poles at about every .3- to .4-mile.
The advantage to this system is that the antennae project much lower power levels than traditional antennae and they distribute a more even amount of energy over the whole area. "You get greater band-width with smaller footprints," he said. McCormack, who works for a cell systems company, added, "This is the wave of the future."
Richard Boule agreed, saying, "Eventually more wireless facilities will be needed as there is a demand for greater band-width, features and services. We must provide for personal wireless service, but not necessarily with a traditional tower. Is having an innocuous antenna, which is not too powerful, on every block or so more appealing than concentrating moderate power on a tower?" Maxson added that, "the right confluence of conditions must exist" to make this kind of system effective. "It depends on the terrain, trees, and the presence of other towers."
Next tasks for consultant
The committee asked Maxson for a proposal that would "identify and evaluate parcels of land [an overlay district] that the community can be comfortable with, identify structure type, height and coverage, evaluate whether the distributed antennae system would work in "Carlisle," and help define ways to deal with the town setback Bylaw." The meeting closed with Maxson accepting that charge.
For more information:
The complete 112-page 2003 report by Broadcast Signal Lab is available on their web site: www. broadcastsignallab.com. Go to the Google search window at the bottom of the page and type in Carlisle. Be sure the button is on "search Broadcast Signal Lab" and search. Then click on "Broadcast Signal lab: White Papers."
The Federal Communications Commission (FCC) web site (www.fcc.gov) can provide some information about the Telecommunications Act of 1996.
Discussions on electromagnetic field safety are available all over the Internet (Google keywords: cell tower safety). Some of the web sites you will find include: www.microwavenews.com and www.nacs.uci.edu/telephone/cellsitesafety.
© 2005 The