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Managing vegetation around utility lines presents a unique set of challenges. Whether you are a tree company looking to do utility line clearance pruning, or a utility looking to hire line clearance pruning crews, the following fundamentals are essential to completing utility tree work safely and successfully:

Fundamentals of Utility Vegetation Management

By Sara Sankowich


Trees and power lines enjoy a delicate coexistence along our roads and highways. In regions like New England, where the tree canopy is dense and beautiful, trees have the potential to cause outages even in the fairest of weather, be it from a broken limb or a fallen tree. Against these challenges, utilities strive to maintain a balance in their right-of-ways, but they must ensure the system can withstand a variety of typical weather events.

Vegetation management (VM) is a critical part of system maintenance for most North American electric utilities because of this coexistence. As the system arborist for a utility in New England, my responsibility is to develop and implement a successful VM program that helps ensure system reliability and mitigates risk. This also includes continuous monitoring and periodic updates and improvements. It is important to always keep sight of your goals, whether they concern reliability, customer satisfaction, or safety — and adjust your program as needed to meet those goals.

Managing vegetation around utility lines presents a unique set of challenges, which requires me to work closely with independent vendors providing qualified line-clearance contract crews and other specialized equipment to ensure they are prepared to deal with everyday hazards they encounter in the field. Whether you are a tree company looking to do utility line clearance pruning, or a utility looking to hire line clearance pruning crews, the following fundamentals are essential to completing utility tree work safely and successfully:


Obtain proper qualifications

Only qualified individuals should prune near power lines. Before an arborist can work around utility lines, it is essential that he or she obtain proper training, experience and credentials. One of the first things a utility will look for when evaluating bids for a project is whether the contractor’s personnel are properly trained and are Qualified Line-Clearance Arborists or Line-Clearance Arborist Trainees. These titles mean they have gone through the training and certification process to learn how to safely work around utility lines. Being able to identify the electric line, how much voltage it conducts, and the appropriate minimum approach distance are essentials for these qualifications. This type of training can be conducted with the assistance of the Tree Care Industry Association’s (TCIA) Electrical Hazards Awareness Program (EHAP). Candidates must complete the requirements of the EHAP training program, and TCIA will issue a certificate of completion, which is valid for one year. Each year a renewal process, with unique training content for a five-year interval, must be completed.


 Understand utility line clearance

Utility arborists face unique challenges when pruning around utility lines. Because of this, it is critical that a tree worker understand the fundamentals of pruning around utility lines before he or she begins working in the field.

Pruning is done for a specific purpose — to keep vegetation from contacting and causing problems with electric utility lines. As a utility system arborist, I do not work for a tree care company, even though I have a forestry education and specialize in tree care. I work for a company that delivers safe and reliable electric power. This is an important point to remember. While we follow all pruning and tree care best practices and genuinely care for the health of our street trees, the overall objective of tree work for a utility is unique.

Utility line-clearance is done on a cyclical basis. A population of trees along a set number of miles of power lines must be continually maintained. To facilitate this maintenance, pruning work is distributed over a set timeframe where maintenance objectives (such as system reliability, safety, customer satisfaction and cost) are evaluated. Often this is a four- or five-year cycle — meaning only one-fourth or one-fifth of the total lines are pruned each year. This cycle setup means there will be a gap in time where the trees are not reviewed or monitored. Workers must think of the pruning “window” or time interval before they will be back again to do work. What is the health of the tree being worked? Will it rapidly deteriorate and become an issue over that four- or five-year timeframe? Unfortunately, utility programs do not usually have the ability to visit and evaluate trees every year like a concerned homeowner may have the ability to do. This changes the amount of risk that may be acceptable, and ultimately changes the work performed on the tree.

This brings up the fact that utility pruning is done on trees that are owned by someone else. Unless the utility owns the land where line-clearance pruning is being performed, the utility does not own the trees being maintained around the power lines. Work must be done on trees owned by municipalities and by private land-owners. This often adds another complex dynamic as sometimes the utility and landowner objectives for the trees are not the same.


Practice good customer service

Customer service is a crucial part of a utility arborist’s job. Unlike the role of a traditional arborist or tree care worker, who is hired by a customer to work on a tree in his or her yard, utility tree crews are assigned to complete work on behalf of the utility company. Tree crews sometimes may encounter homeowners with a different point of view regarding the trees along a property. What might be seen as a dangerous risk to electric service in the neighborhood by the utility might be a valued natural buffer to a property owner. In these instances, tree crews will always benefit from treating customers well, being devout professionals, and acting as a knowledgeable resource. In many cases, tree workers must take extra care to educate the customer on why the work needs to be done, and then clearly communicate the benefits of the tree work so the customer is comfortable with the process.

Customers appreciate personal interaction and care, especially when their property will be impacted by tree work. By assessing customer satisfaction and addressing follow-up issues, tree workers can maintain customer goodwill — and perhaps even build their company brand in the process.

Sometimes, to make an area more resilient to storms, a utility may have to remove a large amount of trees in a small geographic area, and customers are often concerned with tree loss. Utility tree workers in this scenario may find it helpful to offer to replant trees. Offering to replant low-growing trees to replace those that have been removed leaves people feeling more satisfied with the work — even if they decide not to take the company up on the offer.

When project work is complete, utility arborists should follow up with both residential and municipal customers to determine their satisfaction levels and if any additional resources are needed. By finding out how the program went from the customers’ point of view, utility employees may uncover new ways to help things run even more smoothly in the future.


Adjust your aesthetic expectations

Pruning trees to ensure system reliability may involve a different style of pruning than some tree workers are used to. The key difference is that utility tree workers are pruning for a function, rather than purely for aesthetics. Sometimes this means pruning the tree in a way that is not aesthetically pleasing, but that makes the area safe and protects the integrity of the system. Ultimately, a utility’s goal is to use directional pruning to direct growth away from the power lines so the tree remains healthy, avoids contact with power lines, and is still pleasing in appearance.


Know the right tree for the right place

Education is an extremely important component of a utility arborist’s job. When tree workers are in the field interacting with customers, they have a great opportunity to communicate to customers about “right tree, right place.” From a utility perspective, this is the idea that before planting any tree, customers should choose a species and location that keeps the tree clear of overhead wires and away from underground electric lines. Proper tree species selection and placement helps avoid utility line conflicts in the future—and, therefore, helps avoid future outages.

Working as an arborist or tree care worker at a utility company presents many unique challenges, but it can also offer great rewards. Utility tree workers make a significant impact on their communities by helping customers with tree care issues, directing them to the right resources, and, ultimately, ensuring the electric system remains safe and reliable through careful work and planning.


Sara Sankowich is system arborist at Unitil, a public utility holding company, headquartered in Hampton, New Hampshire, that provides electric and natural gas distribution services in New England.

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