Extreme care and understanding of the hazards associated with power lines should be acknowledged before any tree planting or tree maintenance is performed.

National electric standard requires that poles supporting electrical conductors carry the highest voltage at the highest point of attachment. Simply stated, voltage decreases as points of attachment move down the pole. Any conductor (wire) carrying more than 750 volts are considered "high voltage" a high voltage placard (as seen in yellow in the diagram) should be visible. Only qualified line clearance tree workers should work on trees within 10ft. of high voltage power lines.

"Secondary" conductors carry electricity pole to pole. Working on trees near secondary wires should only be done by competent tree workers who are familiar with tree care tools and the potential hazards surrounding these electrical facilities.

"Service Wires" carry electricity from a pole to a home. The point of attachment to a home is called the "periscope". The periscope delivers power to a customer's meter. Tree limbs should be maintained away from service wires and doing so is the responsibility of the property owner, not the utility company. Service wires can be re-routed through a tree should strain or abrasion to the wire become evident. Utility companies can perform this work with advanced notice, but an interruption in power will result. Maintenance on service wire should always be preventative. Tree planting near any power line should be avoided, if pruning becomes necessary, try to do so before a hazard is created.