October 10, 2003 98-R-0859
FROM: Kevin E. McCarthy, Principal Analyst
RE: Zoning and Telecommunications Towers
You asked, on behalf of a constituent, for the following information in connection with an application to the Vernon Zoning Commission to build a personal communications service (PCS) tower:
1. What health and environmental issues are associated with such towers;
2. Are there any local regulations barring the placement of such towers in residential neighborhoods or schools, and whether they can be located in wetlands;
3. Are there any regulations regarding the noise produced by such towers, particularly with regard to the noise produced by generators at the towers;
4. Are there any restrictions on the types of antennas that can be sited on a single tower (co-located)?
According to the Vernon town planner's office, the application that prompted the constituent's letter has been withdrawn as a result of local opposition.
The primary concern raised by PCS towers is the radiofrequency emissions that the antennas on such towers produce. These emissions can heat human skin and have been alleged to cause other health effects. Towers also raise concerns as to their effects on environmentally sensitive areas such as wetlands and their visual impact.
Vernon's zoning ordinance allows towers to be located in all zones and does not bar them from residential areas, wetlands, or areas near schools. But there are restrictions on where they can be located. These include a ban on the use of lots that are smaller than 20,000 square feet and various setback requirements. The ordinance requires the generators used to power PCS facilities to comply with state noise regulations, although there are currently no state regulations that apply specifically to generators.
By policy, Vernon encourages co-location, and gives preferences to proposals to place new antennas on existing towers and structures. Various types of antennas can be located on the same tower, although there are restrictions on the number of antennas a tower can hold and the distance between antennas using the same bandwidth.
ZONING AND TELECOMMUNICATIONS TOWERS
Under Connecticut law, the Siting Council regulates the location of cellular telecommunications facilities but local planning and zoning commissions regulate PCS facilities. PCS is a wireless telecommunications technology that is superseding cellular systems. The technology uses a network of antennas to transmit signals to and from PCS telephones. The PCS antennas to be placed closer to the ground than cellular antennas, and in urbanized areas antennas can often be placed on structures such as buildings and water towers. In more rural areas, the antennas must be placed on towers. PCS operates at a higher wavelength and lower power levels than does cellular systems. As a result, PCS antennas need to be located relatively close together. While a cellular antenna can serve an area of three to 15 miles in diameter, a PCS antenna can only serve an area of 0.5 to 2 miles in diameter. As a result, the deployment of the PCS technology will require substantially more towers than are used in the cellular system.
Health and Environmental Issues
The most salient concern raised by the deployment of PCS systems has been the radiofrequency (RF) emissions they produce. RF emissions, such as microwaves, are non-ionizing and are significantly less powerful than x-rays and other forms of ionizing radiation. But RF emissions can heat conductive materials, including human skin, at short distances. This thermal effect is seen at exposure levels of 10 milliwatts per square centimeter but exposure drops off sharply with distance. As a result, concern regarding this effect focuses on workers building and maintaining PCS facilities. Public exposure is rarely greater than 0.001 milliwatts per square centimeter.
In addition to the thermal effect, some research has indicated that RF emissions can cause non-thermal effects. It appears that exposure to low levels of RF can enhance the release of calcium ions in animal brains. The extent to which this effect is harmful is not known. Other researchers have found that RF exposure is correlated with changes in the immune system, neurological and behavioral effects, and various biological effects such as headaches and fatigue. However, contradictory experimental results have also been reported.
Section 704 of the federal Telecommunications Act of 1996 required the Federal Communications Commission (FCC) to finalize its rules on maximum permissible RF exposure from PCS and other wireless facilities. OLR memo 98-R-0038 describes how FCC set these rules. Under the Telecommunications Act, a municipality cannot regulate a wireless facility on the basis of the environmental effects of its RF emissions if the facility complies with the FCC rules. OLR memo 96-R-0532 describes section 704, which governs municipal regulation of wireless facilities, in more detail.
Among the environmental concerns raised by PCS facilities are disruption of sensitive areas such as wetlands and the visual effect of locating towers on ridgelines, in forests, or in other scenic areas. Under federal law, all towers must comply with the National Environmental Policy Act of 1969 and related laws. The developer of the facility must investigate all of its potential environmental effects and disclose any significant effect in an Environmental Assessment before building the tower. If the tower may significantly effect the environment, the developer must await FCC approval before building the tower.
Vernon's zoning ordinance allows PCS towers to be built in all types of zones, but establishes preferences for where they are to be located. Under the ordinance, the preference is to locate towers in the following order:
1. On existing structures such as buildings and water towers,
2. On existing or approved towers,
3. On new towers located on property with an existing tower,
4. On new towers located in commercial or industrial zones, and
5. On new towers of less than 75 feet in residential in residential zones.
The ordinance also imposes setback requirements on proposed towers. (Zoning ordinances routinely require that structures be set back specified distances from the edge of a front, rear, or side yard.) If the front or side yard of the property is on a street, the tower must be located at a distance equal to 3/4 of the height of the tower or the setback required for the zone, whichever is greater. In other situations, the setback for a side or rear yard differs for residential and nonresidential zones. In a residential zone the setback must be 50 feet for towers up to 75 feet in height and 100 feet for taller towers. In nonresidential zones, these setbacks are 25 and 50 feet, respectively. But, if the lot abuts a residential zone the setback requirement for the relevant yard is the same as though it were in a residential zone. The ordinance also imposes setback requirements on the accessory buildings that house generators and other equipment for the tower. The effect of these requirements is to bar the erection of towers in certain areas. For example, towers cannot be built on residential lots that are less than 100 feet wide because a tower would not meet the side yard setback requirement. The ordinance bars towers, although not antennas, on any lot smaller than 20,000 square feet. Under the Telecommunications Act, municipalities cannot “zone out” PCS or other telecommunication facilities.
The zoning ordinance also limits the tower's height to that allowed in the zone. In no case can a tower be more than 175 feet high or taller than any existing tower on the property. It requires that the application undergo site plan review, which covers such issues as the color of the antennas and fencing for the site. In addition, the ordinance requires that any application to place an antenna or tower on a historic property or in a historic district preserve the historic or architectural character of the area. If the property is in a floodplain (which often overlap wetlands), the application must conform with the relevant provisions of zoning ordinance.
It is possible for PCS antennas to be located on the same tower or structure as cellular or other wireless antennas, and co-location is quite common. There are limits on how many antennas a tower can hold, which vary by the size and type of tower. In addition, antennas using the same radio bandwidth must be located some distance apart from each other to prevent interference. The distance varies by the strength of the signal, among other things.
As a matter of policy, Vernon encourages the maximum use of existing towers to minimize the number of new towers, and encourages telecommunication providers to co-locate their facilities on a single site. If a proposed antenna is not to be located on an existing structure or tower or on a property that already has a tower, the applicant must describe its efforts to locate the tower in such areas. The applicant must demonstrate why these options were not technologically, legally, or economically feasible. Among the acceptable reasons for a decision not to locate the tower in such areas are that (1) the proposed tower would cause unacceptable interference with existing towers or vice versa and (2) the equipment cannot be placed on an existing tower due to structural constraints. Such determinations must be made by a licensed engineer.
Any proposed tower that is 50 to 100 feet high must be designed to accommodate at least one additional user. Towers of more than 100 feet must be designed to accommodate at least two additional users. In addition, the commission may require that the tower be designed to allow for future rearrangement of antennas and allow for placing antennas at various heights.
In addition to this local provision, CGS § 16-50aa includes a procedure where any commercial or public user of the radio bandwidth can apply to Siting Council to require the owner of an existing facility to share the facility, regardless of whether or not the existing facility is subject to council's siting jurisdiction.