Dominion Virginia Power will be removing and trimming trees along the western end of the W&OD Trail until the end of the month to ensure transmission lines are clear of branches.
"The reason we have to cut trees is to maintain a clearance above and below the transmission circuits," said Le-Ha Anderson, spokeswoman Dominion Virginia Power. "The W&OD corridor, that is a transmission line corridor."
Anderson explained although there are two types of power lines, the transmission lines are larger due to a higher voltage of electricity carried from the power plant to substations in each area, requiring more clearance.
For the lines along the W&OD Trail, Dominion Virginia Power (DVP) has a standard that all transmission lines have a 50-foot overhead clearance — on both sides of the line — and that there is nothing below the transmission line higher than 15 feet, said Anderson.
This standard is determined from regulations established by a regulatory board, made up of numerous national councils and committees in the power and electricity industry.
ALTHOUGH THIS TREE-TRIMMING and removing practice should occur every three years, Anderson explained DVP was flexible in the past with its cutting practices.
But, because of pressure coming from the regulatory board, DVP has revisited its original clearance regulations.
The return to stricter regulations resulted in concerns over the removal of trees and the town of Herndon staff to monitor the trimming closely.
"Dominion's clearing started Monday," said Mayor Michael O'Reilly, explaining at a March 1 work session Henry Bibber, director of community development, presented the Town Council with DVP's plan.
"They're not doing as major of a job of cutting in Herndon as they have done in other areas," he said, adding town staff will continue to monitor the trimming and removal process just in case.
Anderson said because of resident complaints regarding the major tree removal and trimming in Vienna, Reston residents also began to voice concerns.
"Reston [residents] have been upset about impending work because they anticipate it's going to be like it was in Vienna," said Anderson.
Because the power lines and poles are closer to the trees in Vienna, Anderson explained DVP had to clear more trees and trim more than they will do in Herndon.
"We've been doing this in a three-year cycle and some of the areas don't even notice anything different because the clearance had already been happening," she said. "In areas like Herndon the lines are high enough that it's not noticeable."
Because more trees are being removed this year due to previous flexible practices, Anderson said DVP has received more complaints.
But, she added, if the selected trees were kept and a power outage were to happen because of those trees, in addition to receiving resident complaints about loss of power, DVP would also have to face the regulatory board.
"We have people asking why we can't just trim the trees as opposed to removing them," she said. "Every time you trim a tree you wound a tree. Over time, that can cause infestation ... and decay."
Anderson said DVP would rather cut the tree down and replace it through its "Right Tree in the Right Place" campaign.
"W&OD Trail is special because it's a transmission corridor, but it is also used by the public for recreation purposes," she said. "We recognize that as a recreation area there are a lot of trees needed for shade, but from a safety and rehabilitation standpoint, we have to have clearance from the lines."
BECAUSE OF RECENT, major power outages, including the 2000 winter storm where trees fell on power lines, the 2003 North Eastern blackout and most recently Hurricane Isabel, Anderson explained pressure has been put on power companies like DVP to be strict with regulations.
Anderson said after each major event studies are conducted to see why power was lost and how that could be prevented in the future.
She said DVP was told "we needed to be more aggressive in our tree trimming practices," after one such study, adding the August 2003 blackout was, in part, caused by "poor vegetation management along a transmission corridor."
"We were flexible in the years past," said Anderson about the tree growth around power lines. "But, because of regulators and events that have happened in the recent past, we're just not willing to take that risk anymore."
JOHN DUDZINSKY, town forester, said areas like Herndon and Loudoun County will not see as much tree cutting as Vienna because the power lines are higher the farther west they run.
"It's very minimal," said Dudzinsky about the removal. "Herndon is a little bit better off ... because the wires are a little bit higher."
He said before cutting, the contractor and foreman hired by DVP and representatives from DVP walked the trail with Dudzinsky and other town staff to properly mark and identify trees that needed to be removed or trimmed.
"The stuff they are cutting right now is stuff they felt that would get too tall," he said.
Currently workers are trimming and cutting near the Herndon Centennial Golf Course.
Dudzinsky said some of the trees they have removed are actually trees he would like to see gone for good.
"Sassafras, Dogwood ... they're leaving all those," he said. "The main trees being taken out are along Crestview and Ferndale Avenue and those are Black Locust. They're also taking out a tree called Tree of Heaven, which is an invasive species, so I am glad to see that go."
In addition, Dudzinsky and Anderson said they will identify places along the trail that could need tree replacement.
"We will replace [trees] with a 6-foot tree that will mature into 15 feet," said Anderson. "This is a long-term approach to help the trail to become aesthetically pleasing while also be healthy."