Line Clearance & Right of Way
Line Clearance - Trees and Power Lines
In order to provide safe and reliable electric service to our members, reduce electrical hazards and power interruptions the trees and brush must be kept clear of all electric power lines. Tri-County REC’s engineering and operations departments have determined what clearances are necessary. The line clearances can vary depending on the voltage of the line and type of construction. The widths of the Co-ops right-of-ways are in our specifications which our contractors go by. The Co-op contracts with professional vegetation management companies whose employees are trained in safely clearing trees and brush away from energized power lines.
Trees in direct contact with energized conductors can cause power interruptions by providing a pathway for the flow of fault current. Trees can be a leading cause of power outages. Trees that become conductive can present potentially hazardous situations. A pro active right-of-way maintenance program benefits the Co-ops distribution system and membership overall. Proper vegetation management in the long term can hold down the costs associated with providing electric service to the Co-op’s members. We appreciate our members cooperation in supporting our vegetation management program.
Preventative System Maintenance
Tri-County REC has over 3,300 miles of distribution lines with 24 substations and metering points. To best maintain safe and reliable electric service to our members Tri-County REC has a year round vegetation management program. Our right-of-way maintenance is planned in advance to periodically cycle through our entire electrical distribution system. The Co-op strives to have all circuits cleared every eight to ten years. The work on circuits of a particular sub or metering point will be completed in its entirety before moving on to another area. Utilizing the industries best management practices by obtaining the best clearances will minimize the expense of future hot spotting on cycle busting re-growth. Hiring crews to do work outside of the established cycle is more costly and should be avoided.
When Tri-County REC designates an area that needs maintenance the members will usually be contacted first by mail, that our contractors will be in the area working where necessary. This gives the members the opportunity to contact our operations department with any questions or concerns. A pre-planner or general foreman will attempt to contact land owners to discuss and plan the necessary work. This contact could be in person, by phone, or a door card. Tri-County REC encourages our contractors to use a combination of directional and natural pruning. Directional pruning means trees are trimmed in such a way as to direct future growth away from the power lines. Natural pruning means the removal of limbs to the trunk or a parent limb without damaging the trunk or leaving a protruding stub. These techniques were developed by the National Arborist Association and published by the American National Standards Institute. The International Society of Arboriculture approves of these methods. Most vegetation management in Tri-County service territory involves side trimming which will remove limbs on the conductor side of the tree or height- crown reduction to provide clearance on trees growing under conductors or too close to side trim. Sometimes through pruning allows for safe clearance on lower voltage lines. If the pruning cannot be done without severely impacting their health or shape the trees may need to be removed. Electric utilities have the right-of-way easements that give the utility the right to remove any tree interfering with the maintenance or operation of the system. After trimming or clearing, brush will usually be lopped with chainsaws or a tractor brush hog along the sides of the right-of-way. Brush may also be wind rowed. It will eventually decompose along the right-of-way and may in some cases provide some food or cover for wildlife. Chipping is done where necessary and there must be access for the equipment. Typically mowed or landscaped areas or steep road side banks require brush chippers. All wood is left on site and belongs to the land owner.
Primary lines are energized at higher voltages and require the most clearance. Secondary and service lines are located between the transformer and the meter. These are a much lower voltage and require much less clearance. Tri-County REC will provide minimal trimming on these reduced right-of-ways. All lines beyond the meter are the member’s responsibility. With advance notice during normal working hours Tri-County REC will send a serviceman to disconnect-drop and reconnect service lines between the transformer and service poles or meters. The member can request this if they are making their own arrangements for heavy trimming or removals to be done by a private tree company at their own expense.
A good vegetation management program helps minimize storm damage and reduces the time necessary to restore power. The loss of electric power over large areas is most often the result of catastrophic weather. Tri-County’s engineers and operators must prioritize power restoration efforts and contractors may be called in to assist our linemen. During an emergency we are not always able to contact the member or land owner in advance for removal of downed or damaged trees. Trees or limbs are left in the safest manner as conditions allow. Cleaning up debris left by storms, accidents or emergency restoration work is the responsibility of property owners.
Plantings and Public Safety
Preventing future right-of-way maintenance costs is something all members can help with by not planting trees under power lines. Tall growing species are not compatible with electric lines. They should not be planted within twenty feet of the center of the right-of-way, further away is better because they can grow to maturity and not require trimming. Low growing shrubs and flowering fruit trees should not be planted too close to poles or directly underneath lines. Co-op linemen and pole inspectors need access to all poles, guy cables, and anchors. On many right-of-ways we have established wild low growing species. These are seen as beneficial, and they help prevent tall growing species from becoming established and often provide food and cover for wildlife. When encountering this type of growth our contractors are instructed to clear center paths and clear around poles, guys, and anchors. For safety concerning children tree houses or swings should never be in trees near power lines. Climbing or portable deer hunting stands should not be in trees near power lines and should never be attached to utility poles.
Integrated Vegetation Management
Tri-County REC employs contractors who will utilize a combination of methods to manage vegetation on our right of ways. Problem trees and vegetation must be identified. Various management options must be considered, evaluated, and implemented. It is best to be consistent yet flexible because of natural variety and diversity. Mechanical clearing and trimming must be combined or alternated with chemical techniques. The desired outcome is stable shrub-grass-forb plant communities that do not interfere with power lines, pose a fire hazard, or hamper access. Eventual domination on the right of way by desirable low growing species will inhibit tall growing species and reduce the need for future maintenance. Other benefits are erosion control and improved habitat for wildlife.
Herbicide Applications on Rights of Way
Years of experience and study have shown that the careful and selective use of herbicides is the safest and most efficient way to maintain right of ways. It is also very cost effective. No applications are done during steady rains. Guidelines are followed concerning all water sources. The herbicides used are approved by the U.S. Environmental Protection Agency, the U.S. Department of Agriculture, and the Pennsylvania Department of Agriculture. The applicators are trained in the safe use and application of herbicides. Applicators are certified and work under the supervision of certified pre-planners and General Foremen.
Cut stump treatments are applied to the cut surface at ground level. The herbicide will penetrate down to kill the remaining root system and inhibit multiple re-sprouting after tree removal or hand cutting of brush. If dense brush has been mowed by a tractor the cut stubble will be treated.
Basal treatment is a selective application to the lower stem of an individual plant. The herbicide penetrates through the bark and disrupts the growing tissues under the bark effectively girdling the plant.
Foliar treatment applications consist of wetting the leaves, branches, and stem. The herbicide is absorbed into the plant and moves to and controls the growth tissues. The plant soon dies and will eventually break up and decompose. Cut stump and basal treatments can be done year round. Foliar applications in Tri-County territory can be done June through September.
The spray program of Tri-County REC is primarily utilized as a mid-cycle follow up on previously cleared right of way. Three to four years after the circuits of a sub-station or a metering point have been cleared and trimmed right of ways are inspected again for re-growth. The tall fast growing incompatible species are targeted for selective foliar applications. Land owners are contacted prior to a crew being sent to the location. This practice greatly benefits the Co-op overall in reducing future maintenance costs and enabling the remaining beneficial plant species to flourish on the right of ways.