BALANCING TREES, MEMBERS AND ELECTRIC RELIABILITY
United’s goal is to keep trees healthy while making sure they do not interfere with United’s electric or fiber optic infrastructure. The amount of tree trimming depends on many factors such as:
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Tree species
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Voltage of surrounding power lines
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Reason for trimming (general maintenance vs. preparation for construction)
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Proximity of tree branches to power lines
United follows a pruning method developed by the International Society of Arboriculture (ISA). This type of pruning keeps the overall structure of the tree strong and more resistant to high winds and heavy ice. At the same time, it directs growth away from power lines.
United does not “top” or “round” trees because this practice is discouraged by the National Arbor Day Foundation.
Overhang Removal - Primary lines will be trimmed "line to sky”, clearing all overhang that is above the power lines.
“V” Pruning - When utility wires run directly over a tree, a v-cut is made to allow branches on either side of the wire to grow naturally.
Side Pruning - Interfering side branches are removed from trees adjacent to power lines.
Tree Removal – Trees within the right-of-way are subject to removal when considering several factors. See Tree Removals section for more information.
Clearance Requirements
United requires a 15 foot minimum clearance or 5 years of growth on either side of the closest conductor on all primary lines. Secondary (service) lines require a minimum clearance of 5 feet around. Fiber optic cable requires a 10-foot minimum clearance or 5 years of growth around the cable. All trees in the right-of-way will be subject to removal; where removal is not possible, trees will be trimmed to the minimum clearance.
In unmaintained areas, vegetation within the clearance distance will be removed. It may be necessary to remove vegetation outside of the clearance area, depending on the species and amount of trimming required.
Additionally, vines will be cut at the base and removed up to 40 inches below the neutral conductor. For pad mount transformers, a 6-foot minimum clearance is required in front of the transformer door to allow United crews access to the equipment and the ability to make any necessary upgrades or repairs.
Tree Debris Removal
Routine Trimming - During normal trimming projects, United contractors will remove and/or chip the tree limbs and debris from member property unless otherwise requested.
Emergency Trimming - United does not remove tree debris caused by a storm or emergency situation. Crews may need to cut broken and uprooted trees to make repairs to our lines, but it is the responsibility of the property owner to remove the tree debris.