The Virginia Department of Environmental Quality (DEQ) on May 1 filed recommendations with the Virginia State Corporation Commission regarding Virginia Electric and Power’s (Dominion) proposed Potomac Yards Undergrounding and Glebe GIS Conversion project, including that the company should ensure that the on-site wetland delineation be verified by the U.S. Army Corps of Engineers to avoid and minimize impacts to wetlands and streams.
As noted in the filing, Dominion has submitted an application to the commission for a certificate of public convenience and necessity to convert the overhead portions of Lines #248 and #2023 located between the Glebe substation in Arlington County and the Potomac Yards North Terminal Station in the City of Alexandria to underground lines and to tie the converted lines into the Glebe substation.
The project, referred to as the Potomac Yards Undergrounding, includes the removal of 550 feet of underground cable and pipe from the Potomac Yards Station to the new manhole #111 and removal of 1,000 feet of cable only from the new manhole #111 to the existing manhole #110, the DEQ said. About 2,100 feet of new underground cable would be installed from the manhole #110 to the manhole #111 to the Glebe substation, of which 1,100 feet would be installed via microtunneling and 1,000 feet would be installed in existing underground right of way (ROW).
The DEQ added that the project also includes the conversion and rebuild of the existing Glebe substation to a gas insulated substation (GIS), known as the Glebe GIS Conversion.
The project is proposed to maintain consistency with NERC reliability criteria, as well as with Condition #5 of the existing special use permit (SUP) issued by the City of Alexandria in 1996, and extended in 2013.
The DEQ added that the Potomac Yards Undergrounding would be built on existing company owned property and ROW, as well as new ROW across Four Mile Run. The Glebe GIS Conversion would take place entirely on company owned property, the DEQ said, adding that the anticipated in-service date for the project is May 2022, with construction expected from March 2020 through May 2020.
Discussing subaqueous lands and tidal wetlands, the DEQ noted that the Potomac Yards Undergrounding portion of the project crosses Four Mile Run, which is tidal. Dominion should coordinate all instream activities with the state Department of Game and Inland Fisheries (DGIF), the DEQ said, adding that to minimize adverse impacts to anadromous fish, any instream activities may be required to adhere to a time-of-year restriction (TOYR).
The DEQ also noted that to minimize the adverse impacts of linear utility/road project development on wildlife resources, the DGIF offers such general recommendations as that the company should avoid and minimize impacts to undisturbed forest, wetlands, and streams to the fullest extent practicable.
Among other things, the DEQ also said that impacts to unrecorded and/or unevaluated archaeological and historic architectural resources remain unassessed. The DEQ said that the state Department of Historic Resources (DHR) recommends, for instance, avoidance, minimization, and/or mitigation of moderate to severe impacts to Virginia Landmarks Register/National Register of Historic Places-eligible/listed resources by Dominion in consultation with the DHR and other stakeholders.