PSO Trims Some Trees


By Kristen Wright, senior editor

Electricity consumers in the northeastern Oklahoma region known as Green Country didn’t welcome the state’s mandatory 4-year tree-trimming cycle. The thorny issue arose in 2005 when the Oklahoma Corporation Commission (OCC) approved an Interim Reliability Cost Adjustment Rider to fund an electric utility’s vegetation management program.

Two months later, the commission approved a change making the rider permanent with a cap of $20 million annually. Eight months after that, the Reliability Enhancement Cost Adjustment Rider was increased to $23.7 million a year to include underground conversion projects. Without increasing the rider, the number of tree crews would shrink from 150 to 27. Customers weren’t happy about the increased emphasis on tree trimming—they loved their trees. So in 2005, the utility upped its customer outreach. It began offering neighborhood meetings six weeks prior to performing its tree trims.

“In the earlier years of this, back in 2005-2006, we had quite a few neighborhood and community meetings as people were just getting acquainted,” said Stan Whiteford, spokesman for Public Service Co. of Oklahoma (PSO), a Tulsa-based unit of American Electric Power Co. Inc.

PSO had not been doing enough to inform and interact with customers, said Jennifer Leber, the company’s reliability manager. She started as an engineer at PSO in 1998 and was a first responder in the line department. These days Leber is responsible for providing analysis on outage causes. The utility needed to convey its outage-prevention message better to customers and gain their support.

PSO’s utility-initiated communication became much more frequent and timely. The extra effort includes delivering letters to customers in neighborhoods that will be affected by tree trims five weeks prior to the work, Leber said.

The meetings and letters provide an overview of PSO’s forestry program and make its forestry information line available to customers before they see any tree work performed in their area. The letters also explain that trees are the leading cause of power outages, contribute to power blinks, hamper maintenance and can delay service restoration.

A January 2006 letter from PSO Forestry Supervisor Richard Bewley, for example, used several bulleted items to inform customers in locations subject to upcoming trims.

  • Bewley stated which contracted tree-trimming company would perform the work under the direction of PSO’s foresters using guidelines developed by the American National Standards Institute and the International Society of Arboriculture to protect the health of the trees that are trimmed and to comply with the National Electrical Safety Code.
  • Bewley stated that work planners soon would be in the neighborhood to draw a tree-trimming plan for each yard that would be affected and would discuss it with homeowners. For homeowners unavailable to meet, the work planner would leave his or her cell phone number and trim plan. The goal was to ensure work planners are completely accessible, approachable and friendly.
  • Bewley explained how trimming trees enough to allow for four years of growth before subsequent pruning is needed maintains electric service reliability and meets state reliability requirements. In addition, the letter touted PSO’s willingness to work with customers to find agreeable solutions. “In response to customer feedback, we now offer two basic approaches to accomplish the tree work and gain the needed clearance between the power lines and the trees growing alongside and underneath the lines,” Bewley wrote. PSO can perform all tree work or customers can hire and pay a private tree maintenance contractor for annual or more frequent tree work in consultation with PSO foresters. If customers choose the PSO option, the utility also removes smaller brush and limbs from the yard and leaves stacked logs for use as firewood.
  • Bewley stated that under certain circumstances where a tree must be removed, PSO may offer a homeowner a tree voucher for use at participating nurseries, and PSO foresters are happy to discuss appropriate tree species and where customers should plant them.
  • Bewley’s letter also stated that where PSO must remove tall or fast-growing trees that threaten power lines along rights-of-way, the utility will work with individuals or groups on providing suitable replacement trees.
  • Bewley’s letter explained PSO’s commitment to working with customers individually to resolve tree-trimming issues. If an agreement cannot be reached, however, a dispute enters the Early Settlement Program, which is Oklahoma Supreme Court-sponsored mediation.
  • The letter also noted PSO’s participation in a Community Oversight and Review Committee to develop a plan to maintain and improve Tulsa’s “urban forest.” Committee members include representatives from the city of Tulsa, homeowner associations, local businesses, the OCC and other civic organizations.

PSO began seeing more content customers after the utility increased its pre-trim communication efforts, Whiteford said.

“I can only hope they are seeing the fruits of that, and as a result, we have much fewer requests for neighborhood meetings,” he said. “It seems people are beginning to understand.”


PSO customers noticed the increased numbers of tree crews, Bewley said. He’s worked more than 20 years as a PSO forester. He’s also a certified arborist through the International Society of Arboriculture. According to Whiteford, Bewley has “personally met every tree” in the system.

PSO’s forestry division includes five utility foresters: one each for the northern, southern and southwestern sections, and two in the Tulsa metro area. PSO uses 15 contracting utility foresters, about half of whom are in the Tulsa area and half are in outlying districts. The rest of the force is contract labor, Bewley said.

“When we went to over 200 tree crews, it did raise a lot of attention,” he said. “You’re much more noticeable.”

Sometimes the lay of the land makes crews more noticeable. Southwestern Oklahoma features rocky canyons, and southeastern Oklahoma has steep mountains with swampy lowlands. Sometimes trimming involves manual saws mounted to helicopters. The terrain can be inhospitable, Bewley said.

“I think they build a fence under every one of our power lines,” he said. “And then they grow trees on them.”

In addition to trimming trees, PSO’s vegetation management efforts include increased use of herbicide to change vegetation types in certain areas and tree-growth regulators, which improve crew safety, Bewley said.

Customers See for Themselves

PSO customers’ newfound understanding can be attributed partly to increased utility communications and partly to customers’ seeing for themselves what electric utilities have preached for years. In December 2007, Green Country fell victim to the ice storm from hell.

One to 3 inches of ice encased the state. President George W. Bush declared all 77 counties disaster areas, and the state medical examiner attributed 29 deaths to the worst ice storm in Oklahoma history.

Whole trees, branches and power lines heavy with ice splintered and crashed onto whatever lay beneath, including people, homes and pets. The glazed debris littered city blocks and country roads, rendering many impassable but on foot.

More than 634,000 homes and businesses in the state lost power, according to the Oklahoma Department of Energy Management. Of those, some 253,000 were PSO customers. Not everyone, however, lost power. Extension cords snaked across streets for days. Some residents had generators. Many had fireplaces. And some had chainsaws. Trash trucks and emergency vehicles couldn’t travel the streets until the debris and downed lines were cleared. And when the debris was moved from roadways, it had no where to go but up. Piles grew as high as rooflines in some neighborhoods, prompting rodent-infestation fears among homeowners.

But the storm didn’t keep linemen and tree trimmers away from the more than 230 cities and towns served by PSO. They came from 14 states to help restore power across the 30,000-square-mile territory in eastern and southwestern Oklahoma. The area includes more than 21,974 miles of distribution lines and more than 3,628 miles of transmission lines.

After the cleanup, many residents wondered how the storm would have affected them had their power lines been buried underground instead of overhead. The following summer the OCC issued a report on the subject. It found that burying the state’s distribution lines would cost more than $20 billion—more than $16,000 a customer.

“We’re really not starting those projects back up,” Whiteford said.

Money Trees

As of May 2010, PSO is officially on the second cycle of its 4-year trim cycle. The company expects fewer costs this round because the heavy cutting was performed during the first round. This time just more than 100 crews are performing lighter maintenance with handsaws, Bewley said.

“We’re enjoying a lot less tree interference with our power lines, which makes it a lot safer for the workers,” he said. “We are getting back to the trees just before they’re reaching the power lines.”

The cost to customers has been roughly $2 a month on their bills since the OCC approved the rider. Actual customer costs vary quarterly depending on the amount and type of vegetation management work performed. It’s a pay-as-you go plan in which PSO submits tree work expenses quarterly to the OCC. If the submissions fulfill OCC requirements, the costs are included in customer bills for recovery.

Leber said PSO has seen an 87 percent improvement in outage frequency caused by trees in rights-of-way and a 93 percent improvement due to SAIDI.

“Part of the program was proactive line maintenance,” she said. “That further reduced outages. Those are the benefits our customers have seen—their lights are staying on.”

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