Work on an overhaul of Dominion Energy’s electric transmission line between Vienna and Idylwood is expected to start next month, the utility says.
The project will replace the wires — known as a reconductor — that run parallel to a 3.9-mile section of the Washington & Old Dominion Trail, connecting the Clark substation at 375 Center Street near Caboose Tavern in Vienna and the Idylwood substation at 7701 Shreve Road.
The existing line is aging and needs to be upgraded to accommodate growing electricity demand in the area, officials with Dominion and its consultant Dewberry Engineers told the Vienna Town Council during a presentation at its June 3 meeting.
“It’s a transmission line upgrade, meaning the conductor that’s in the air, they need to replace that conductor for growth patterns and reliability type of needs in the project,” Dewberry project manager Andrew Dahlman said.
The new reconductor will support the same 230 kilovolts as the existing one, but it will have a new design that allows for a higher amperage, or a stronger electrical current, increasing its capacity, according to Dahlman.
Dominion has been working to update transmission lines throughout its system that date back to the 1970s, including with projects in eastern Loudoun County and Prince William County.
Paul Schmeling, a construction manager with Dominion Energy, likened the replacement to a road widening.
“When the line was put in, Northern Virginia was much, much smaller,” Schmeling said. “I live in Warrenton and there was nothing there. Now that the area has grown the way it has, that two-lane road doesn’t work anymore. You now need a four-lane road. It’s like that but for electricity.”
The Clark-Idylwood reconductor project will be implemented in two phases, starting with a roughly 2.8-mile segment from the Clark substation to Sandburg Street in Vienna. The remaining 1.1 miles from Gallows Road to the Idylwood substation are expected to be addressed in 2025.
Preliminary work on the first phase is scheduled to start in July and will primarily involve setting up equipment so crews can get access to the transmission line. The actual replacement will likely begin in the second or third week of November, a time frame chosen to avoid interfering with Election Day.
“We’re aware the Vienna Community Center is used as a polling place, so we’re trying to minimize the impact there,” Dahlman said. “We won’t do any work on voting day in that area.”
During that period, which could last one to two weeks, depending on the weather, trail users will be detoured around the construction on weekdays. The exact route is still being finalized, but Dahlman says the goal is to ensure pedestrian and bicyclist safety, so sidewalks or shared-use paths, crosswalks, signalized crossings and curb cuts will be included as much as possible.
Once the new conductor is installed, crews will remove the temporary construction equipment and restore the lines to normal operations. No power outages will be needed, Dahlman said when asked by Councilmember Roy Baldwin.
For the second phase of the project, Dominion will need to cross I-66, I-495 and Metro’s train tracks.
“When that happens, which will be next spring-to-summer time frame, there will be some impacts to that area,” Dahlman said.
In light of Vienna’s new tree preservation requirements, which will take effect on July 29, some council members urged the project team to limit tree trimming and clearing as much as possible.
Survey teams are currently staking out the transmission line easement, and a Dominion forestry team will then evaluate that area for any trees that might fall or run into the power lines, according to Dahlman.
“We have a lot of interest in the town in preserving trees to the extent that we can, particularly in areas where they’re very visible and enjoyed, and of course, one area like that is the [W&OD] trail,” Councilmember Jessica Ramakis said. “So, there may be opportunities where there’s a judgment call, but I would ask that be considered sparingly and only really take down trees that really are a risk to the project and not in good health.”
