Why does Eversource invest in tree work?
- To maintain electric service to our customers
- To assure visual and physical access to our equipment
- To find trouble sooner and fix it
- To prevent equipment damage - replacing and repairing equipment is very time-consuming and expensive
- To assure the safety of the public, our employees and contractors, and for other utility workers (phone, cable TV) who may be working nearby
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 New England, more than 90 percent of the outages on our system are caused by trees and tree limbs.
By working strategically and proactively, our tree-trimming activities reduce both the number and duration of outages for customers. Tree trimming is the most effective means of improving reliability for customers, our tree work also benefits the communities we serve by removing dead or diseased trees that not only threaten the lines and rights-of-way but also public roads.
Who performs Eversource's tree work?
Our company certified Arborists will oversee contractor crews that are working on trees to improve reliability for our customers. In the event of severe weather or widespread outages the number of contractors will increase substantially.
Every year our company invests in proactive vegetation management programs identifying tree trimming and woody vine removal on and around utility poles. All of this work is performed by contractor tree crews who are trained in all aspects of 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. These guidelines ensure that pruning cuts minimize injury to the tree and consider the individual characteristics (size, shape, form and condition) of each tree.
How is tree work performed?
Before any tree work can be performed on private property, Eversource’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.
Eversource undertakes two types of tree work:
- Scheduled Maintenance Trimming (SMT) is performed on a regular basis by electrical circuit, with a goal of trimming roughly 15 to 25 percent of NU's circuits every year. The clearance required for SMT is eight feet on sides, 10 below, and 15 feet above the line.
- Enhanced Tree Trimming (ETT) is higher-priority tree trimming and entails work closer to substations that would potentially impact more customers. ETT protects the "backbone" of the distribution system and requires clearances of eight feet on the sides, 10 feet below and removal of all overhanging limbs whenever possible or a minimum of 20 feet above the line.
Trees that are decayed, insect-infested, damaged or structurally weak may be removed.
Small trees and saplings that are capable of growing into the conductors are normally removed before they grow tall enough to interfere with the lines.
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 will callous over and prevent decay of the pruning wound.
When is tree work performed?
Line clearance tree work is performed year round. Crews prune on a four- to seven-year cycle.
Will Eversource trim the trees around my service wire?
We will remove branches or limbs in direct contact with Eversource wires located between a Eversource pole and the house only when trees or branches are applying pressure to Eversource service wires. Service wires are insulated for leaf and occasional branch contact, but direct rubbing can eventually damage the wires. Please call Eversource at 800-880-2433 for more information on removing branches against your service wire.
What should I do if I need to have a tree cut down near wires?
Homeowners can hire professional tree pruning contractors for pruning work near these lines. We may temporarily remove pole-to-house lines for professional tree contractors so they can prune or remove trees safely. Please call Eversource's New Service Clearing Desk at 800-880-2433 for more information on temporarily "dropping" your service wire.