It took an additional three months to hammer out final details, but Fairfax County supervisors on July 16 unanimously approved Dominion Energy’s plans to improve its main substation in Tysons.
The substation, which was built in 1964 and expanded in 1970, sits on 3.29 acres at 8440 Tyco Road next to the Dulles Airport Access Road. Dominion will make the facility more efficient and less-cluttered by installing gas-insulated equipment, which uses less space than standard air-insulated technology.
The gas-insulated equipment will supplant older technology on the western side of the property and be enclosed in a building. Dominion will replace three 70-foot-tall “backbones” at the substation with two 75-foot-high ones. These will be located on lower-level areas of the property to minimize the height increase’s visual impact.
The utility also will remove six distribution centers, place existing distribution lines underground and install a 75-foot-tall “static pole” to guard against lightning.
The upgraded Tyco Road facility will help Dominion meet future electricity demands in Tysons, relieve the burden imposed on surrounding substations and prevent the utility from violating reliability standards.
The Tyco Road substation also will be the end point for a future underground-transmission line running between Idylwood Road and Tysons.
“Don’t forget we have a lot to do with the Idylwood substation still,” Supervisor Linda Smyth (D-Providence) reminded Dominion’s representatives at the meeting.
Dominion also plans to construct a new substation south of the Spring Hill Metro Station in Tysons. Substations connect with high-voltage transmission lines and reduce the voltage to levels where it can be used by residents and businesses.
No members of the public spoke at the Board of Supervisors’ July 16 hearing on the substation proposal. The county’s Planning Commission on April 3 unanimously recommended approval of Dominion’s plans, but county official spent the intervening months ironing out details, such as the site’s screening wall.
Dominion will shield the facility from the surrounding area with a 12-foot-tall textured precast-concrete wall. The site currently is surrounded by a 7-foot-high chain-link fence with a foot of barbed wire on top.
In addition, Dominion will add stormwater-management equipment and plant 75 new trees and 77 new shrubs at the site, and install an 8-foot-wide sidewalk and street trees along Tyco Road.
Utility officials have provided design alternatives for the substation that will accommodate the planned access ramp from Greensboro Drive to the Dulles Access Road, said Sheri Akin, a senior planner with McGuireWoods.
“This site has been here since the 1960s with relatively little improvement to it,” Akin said. The new equipment “will be less cluttered and technologically superior,” she added.