Interim Guidelines For Recommendations On Communications
Construction, Operation, and Decommissioning
United States Department of Interior
Fish and Wildlife Service
Washington, DC 20240
- Any company/applicant/licensee proposing to construct a new communications
tower should be strongly encouraged to collocate the communications
equipment on an existing communication tower or other structure (e.g.,
billboard, water tower, or building mount). Depending on tower load
factors, from 6 to 10 providers may collocate on an existing tower.
- If collocation is not feasible and a new tower or towers are to
be constructed, communications service providers should be strongly
encouraged to construct towers no more than 199 feet above ground level
(AGL), using construction techniques which do not require guy wires
(e.g., use a lattice structure, monopole, etc.). Such towers should
be unlighted if Federal Aviation Administration regulations permit.
- If constructing multiple towers, providers should consider the cumulative
impacts of all of those towers to migratory birds and threatened and
endangered species as well as the impacts of each individual tower.
- If at all possible, new towers should be sited within
farmsî (clusters of towers). Towers should not be sited in or near
wetlands, other known bird concentration areas (e.g., state or Federal
refuges, staging areas, rookeries), in known migratory or daily movement
flyways, or in habitat of threatened or endangered species. Towers
should not be sited in areas with a high incidence of fog, mist, and
- If taller (>199 feet AGL) towers requiring lights
for aviation safety must be constructed, the minimum amount of pilot
obstruction avoidance lighting required by the FAA should be used.
Unless otherwise required by the FAA, only white (preferable) or red
strobe lights should be used at night, and these should be the minimum
number, minimum intensity, and minimum number of flashes per minute
(longest duration between flashes) allowable by the FAA. The use of
solid red or pulsating red warning lights at night should be avoided.
Current research indicates that solid or pulsating (beacon) red lights
attract night-migrating birds at a much higher rate than white strobe
lights. Red strobe lights have not yet been studied.
- Tower designs using guy wires for support which are proposed to be
located in known raptor or waterbird concentration areas or daily movement
routes, or in major diurnal migratory bird movement routes or stopover
sites, should have daytime visual markers on the wires to prevent collisions
by these diurnally moving species. (For guidance on markers, see Avian
Power Line Interaction Committee (APLIC). 1994. Mitigating Bird Collisions
with Power Lines: The State of the Art in 1994. Edison Electric Institute,
Washington, D.C., 78 pp, and Avian Power Line Interaction Committee
(APLIC). 1996. Suggested Practices for Raptor Protection on Power Lines.
Edison Electric Institute/Raptor Research Foundation, Washington, D.C.,
128 pp. Copies can be obtained via the Internet at http://www.eei.org/resources/pubcat/enviro/,
or by calling 1-800/334-5453).
- Towers and appendant facilities should be sited,
designed and constructed so as to avoid or minimize habitat loss
within and adjacent to the
tower ěfootprint.î However, a larger tower footprint is preferable
to the use of guy wires in construction. Road access and fencing should
be minimized to reduce or prevent habitat fragmentation and disturbance,
and to reduce above ground obstacles to birds in flight.
- If significant numbers of breeding, feeding, or roosting birds are
known to habitually use the proposed tower construction area, relocation
to an alternate site should be recommended. If this is not an option,
seasonal restrictions on construction may be advisable in order to
avoid disturbance during periods of high bird activity.
- In order to reduce the number of towers needed in
the future, providers should be encouraged to design new towers structurally
to accommodate the applicant/licenseeís antennas and comparable antennas
for at least two additional users (minimum of three users for each
tower structure), unless this design would require the addition of
lights or guy wires to an otherwise unlighted and/or unguyed tower.
- Security lighting for on-ground facilities and equipment should
be down-shielded to keep light within the boundaries of the site.
- If a tower is constructed or proposed for construction, Service
personnel or researchers from the Communication Tower Working Group
should be allowed access to the site to evaluate bird use, conduct
dead-bird searches, to place net catchments below the towers but above
the ground, and to place radar, Global Positioning System, infrared,
thermal imagery, and acoustical monitoring equipment as necessary to
assess and verify bird movements and to gain information on the impacts
of various tower sizes, configurations, and lighting systems.
- Towers no longer in use or determined to be obsolete should be removed
within 12 months of cessation of use.