Trimming cycles are highly dependent on tree growth rates and the type of electric facilities in the area. We trim the distribution circuits in our system on a 4-year cycle and also perform reliability enhancement trimming as required.
Why don't you consider aesthetics when pruning trees?
ComEd follows the American National Standards Institute (ANSI) A300 Part 1 when pruning trees to maintain proper line clearance. The following factors represent a prioritized list of considerations that ComEd crews take into account when performing utility line clearance work:
Can you prune my tree lightly?
ComEd line clearance specialists are trained in proper arboricultural pruning techniques which follow industry professional standards (ANSI A300, part 1) and the best management practices published by the International Society of Arboriculture. Still, the amount of pruning your tree(s) may require for line clearance depends upon several factors:
When trimming the tree, can it be "shaped" or "rounded over" on the top?
We do not "round trees" over because it's not good for the health of your trees. We subscribe to a method of pruning called lateral and directional pruning. These methods are endorsed by the tree-care industry as being the best pruning techniques for the health of the tree. The basis for lateral pruning is that each limb removed from a tree is removed either where it joins another limb or at the trunk. This procedure is different than the philosophy of "rounding" trees over in which limbs are cut at arbitrary points normally leaving unhealthy "stub" cuts. Directional pruning involves cutting a limb back to another limb (or lateral) so that future growth of the resulting limb is directed away from the power lines. With directional pruning techniques, tree growth causes minimal impact to public safety and electrical service.
ComEd does not perform non-emergency tree trimming on trees located near the power line running directly to customers' meters (also known as the service line). If a customer is concerned about tree growth near the service line, ComEd will de-energize the service line while the customer or a qualified tree trimmer performs the trimming, and then re-connect the service line when trimming is finished. The customer's home will be without power while this is done. There is no charge for this service. Please contact ComEd at 1-800-EDISON-1 (1-800-334-7661) at least 5 days prior to schedule an appointment.
Does ComEd maintain vegetation for telephone and cable television lines?
No. Please contact your local communication provider for further information.
Is there an alternative to repeated tree pruning which sometimes results in the tree's disfigured appearance?
Yes. The property owner may want to have trees removed to avoid the need for future periodic pruning. Small "volunteer" trees or trees inappropriately planted too close to lines are good candidates for removal. ComEd will be happy to review possible candidates on a case by case basis. Please contact us at 1-800-Edison-1 (1-800-334-7661) to schedule a visit.
Do you paint open pruning cuts?
ComEd's contract crews do not use commercial tree paint products because these are no longer recommended in the arboriculture industry. The latest research indicates that such dressings are primarily cosmetic and do not stop decay. Proper placement of pruning cuts will allow the tree to grow over the cut.
Why do you prune the trees back so far?
ComEd's vegetation management program is designed to minimize interruptions to electrical supply. The closer a tree grows to a high voltage line, the greater the amount of pruning required to maintain a minimum clearance between the tree and the power wires. The amount of pruning required varies based on line voltage, line construction, proximity of the trees to the line and tree species. All pruning is done in conformance with proper arboricultural pruning techniques, which follow industry professional standards (ANSI A300, part 1) and the best management practices published by the International Society of Arboriculture.
Will pruning hurt my tree?
ComEd uses only professional contractors and requires that they follow American National Standards Institute (ANSI) A300 for tree pruning. These pruning techniques minimize the potential damage caused to trees.
Why doesn't ComEd put the lines underground?
Despite being extremely expensive, and sometimes costing several times more than overhead construction, an underground line is not problem-free for trees. During construction, tree roots may be cut. Cutting tree roots can lead to tree decline or death or may cause a tree to uproot in high winds. Future maintenance of underground lines may also cause damage to existing tree roots, landscape plantings and lawns.
Pruning trees around power lines should only be attempted by trained professionals. Serious injuries and even fatalities have occurred when untrained individuals do this work without the assistance or supervision of qualified professionals. ComEd recommends that you do not attempt to trim or prune trees and vegetation located near any power lines. Please contact ComEd at 1-800-Edison-1 (1-800-334-7661) if you have questions or concerns.
Why is ComEd pruning and removing trees?
Trees that contact transmission lines can cause service interruptions, safety concerns and can even damage electrical equipment. ComEd is mandated by state and federal agencies to eliminate power interruptions caused by tree and vegetation interference and so uses the industry's best practices to manage growth along or near wire and border zones of transmission power lines.
The wire zone is the area directly beneath the transmission wires, plus an additional 10 feet on either side. Any vegetation that can grow more than 10 feet high is not allowed in the wire zone. Trees growing in the wire zone are often removed (especially tall-growing species).
The border zone is the area on each side of the wire zone that extends to the edges of the transmission line right-of-way (the corridor where electrical towers, poles and wires are located). Vegetation in this area is pruned to eliminate a tree's ability to grow or fall into wires. If the pruning of certain trees and vegetation is impractical or deemed to be ineffective, they are removed.
Herbicides control targeted undesirable or incompatible plant species. ComEd employs only professional State Certified applicators to control unwanted vegetation under its power lines and on its rights-of-way so that this vegetation won't interfere with the power lines, causing interruptions in electrical service or presenting a safety issue.
If you do not find an answer to your questions or concerns on this Web page, or among the pages located within ComEd.com/Trees, you may contact us at 1-800-Edison-1 (1-800-334-7661) and ask to speak with a Vegetation Management representative.
ComEd's recommendations depend upon whether the power lines in question are transmission or distribution lines; as well as on the type of utility facility and property ownership. ComEd does not allow trees underneath transmission voltage power lines. But ComEd can allow trees with a mature height of less than 25 feet beneath distribution lines. If you have questions, please contact us at 1-800-Edison-1 (1-800-334-7661).
Does ComEd take away storm damaged trees or branches?
ComEd removes the branches or trees from the electrical wires and places them on the ground. ComEd clearance crews do not dispose of branches, logs or other debris associated with trees damaged by storms, ice, winds or other natural circumstances. Our crew's first priority in response to any storm is to restore electric service to customers as quickly and as safely as possible, and to keep electrical facilities safe. Assisting customers with the disposal of tree debris would impede our crews' ability to respond in a timely manner to other power outage situations, and it could also create safety concerns.
In most cases, stumps will be cut off flush with the ground. Trees that are located in fencerows or that contain metal, cement, rocks, etc., will be cut above the interfering material. ComEd's vegetation management crews do not remove tree stumps or the roots of trees.
Wood that is too large for the chipper is cut into manageable lengths and left on the property, near the base of the tree. Disposal or use of all such wood is the property owner's responsibility. All other trimmings are recycled by ComEd. Through a partnership with the Brookfield Zoo, ComEd's vegetation management department donates branches with leaves to the zoo on a regular basis for their Browse Program. (Browse is a natural material that promotes zoo animals' dental and gastrointestinal health, in addition to providing them with mental and physical stimulation). All other tree trimmings are recycled by turning them into landscape mulch.
Our tree-pruning program adheres to the practices contained in ANSI A300, and include:
ComEd vegetation management crews are specially trained and conform to Occupational Safety and Health Administration (OSHA) Regulations and American National Standards Institute (ANSI) Standards in order to safely work on trees that are in proximity to electrical conductors. ComEd also requires that line clearance specialists be trained in proper arboricultural pruning techniques, which follow industry professional standards (ANSI A300, part 1) and the best management practices published by the International Society of Arboriculture.
Electric utilities are proactive and prune trees BEFORE they pose a risk to the power lines. Factors such as trees swaying in the wind, sagging with ice or snow, or uprooting in storms are examples of problems that can occur without warning. Tall growing vegetation under power lines can also pose a threat as the conductors can sag during high temperatures. Consequently, utilities must also consider the electrical "flash distance" – also known as the distance that a grounded object can attract an electrical shock from an energized high-voltage line. Addressing vegetation before it causes a problem is a smart, efficient and safe way to help prevent the development of dangerous conditions in the future.
ComEd is committed to providing customers with reliable electric service. Tree branches that contact power lines can cause interruptions to power delivery. These interruptions, aside from being inconvenient, also pose a threat to public health and safety. For example, power supply interruptions affect those on life support, and may disrupt schools, hospitals, traffic signals and sewer and water pumping facilities. Additionally, Federal standards mandate that utilities have a vegetation management program to prevent widespread outages on the transmission system, and the State of Illinois requires ComEd and other utilities to provide reliable electricity to customers. ComEd's program is designed to minimize service interruptions by clearing limbs, trees, vines and other vegetation away from power lines on a regular basis.
