Before any tree work can be performed on private property, WMECO’s contractors must notify tree owners, except under certain easement conditions. Door hanger notifications are provided when tree owners are not home. For work on public property, permission generally is granted by the appropriate highway official or municipal tree warden.
WMECO’s program has many components:
Limbs are pruned using a tree care industry technique, known as target pruning. Each limb is pruned back to a point where it meets the branch collar so that the pruning cut calluses over and prevents decay of the pruning wound. Additionally, “directional pruning” techniques are used to promote growth away from our lines.
On a typical day, WMECO’s certified Arborist oversees approximately 15 contractor crews that are working on trees to improve reliability for our customers. In the event of severe weather or widespread outages, this number increases substantially.
Vegetation management identifies trees requiring trimming, tree removal, and woody vine removal on and around utility poles and wires. All of this work is performed by contractor tree crews who are trained in tree work and the safe work practices necessary for working near energized electric lines.
Crews complete the work in accordance with professional standards established by the American National Standards Institute and the International Society of Arboriculture. Following these guidelines helps ensure that pruning cuts minimize injury to the tree and consider the individual characteristics (size, shape, form and condition) of each tree.
During the course of a year, trees are responsible for approximately 25 percent of all service interruptions. When a storm with high winds or heavy, wet snow comes through Massachusetts, more than 90 percent of customer outages on WMECO’s system are caused by trees and tree limbs.
Trimming activities reduce both the number and duration of outages for customers, and is the most effective means of improving service reliability for customers. It also benefits the communities we serve by removing dead or diseased trees that not only threaten power lines and rights-of-way but also public roads.