ComEd performs routine tree and vegetation maintenance on regular cycles. These cycles are four years in length. ComEd also performs some mid-cycle work where trees are especially fast growing, or there are other problems that may result in interruptions to electric service.
Electric utility pruning is often perceived differently from other types of pruning because the objectives are different. However, when pruning trees in urban and suburban environments, the tools and methods used are similar to those used for other pruning purposes. Likewise, utility arborists are expected to adhere to the same professional standards as other arborists.
ComEd employs professional contractors to perform its line clearance work. The work is performed in accordance with American National Standards Institute (ANSI) Standard A300, Part 1: Tree, Shrub, and Other Woody Plant Maintenance – Standard Practices, Pruning.
The type of tree pruning used by ComEd is called directional pruning (or natural target pruning). This method is designed to encourage the tree to grow away from the electric lines and has been adopted as a national standard (ANSI A300, Part 1) and the International Society of Arboriculture as a Best Management Practice. Directional pruning allows ComEd to take characteristics of each tree into consideration when determining the extent of pruning needed. The pruning clearances to which we hold our contractors are based on the growth rate and mature size and shape of each tree, the location of the tree in relation to the power line, the type of utility facility, and a cycle length of 4 years.
ComEd has been recognized for 13 years as a Tree Line USA utility by the Arbor Day Foundation for our sustained commitment to proper tree care and maintenance while continuing to meet service objectives. The requirements for the award include training workers in quality tree-care practices, educating the public about planting trees for energy conservation and helping customers to plant appropriate trees near utility lines.
CORRECT: The diagram above shows how directional pruning guides the growth of the tree away from the wires.
INCORRECT: The diagram above shows how “topping” or “rounding over” of trees can cause a flush of fast growing sprouts that grow directly back into the wires. Find out further information about how to avoid tree and utility conflicts by visiting the International Society of Arboriculture's website. Additional information about reducing tree and utility conflicts is available on the Arbor Day Foundation website.