Dominion Energy transmission lines span the James River near Surry, Va., seen from the Hog Island Wildlife Management Area, June 18, 2019. (Photo by Parker Michels-Boyce for the Virginia Mercury)

WILLIAMSBURG — On a map propped on an easel in a dimly lit conference room of the Hilton DoubleTree, the transmission line across the James River looks like one of a dozen alternatives for bringing power to northern Hampton Roads.

But about six miles away, off the map and on the ground, the line takes on different dimensions: 7.76 miles (length), 17 (towers), 130 to 295 feet (tower heights), 500 (kilovolts). The numbers are so precise exactly because they aren’t hypothetical. All of these power lines and the infrastructure holding them in place have already been built. The Surry-Skiffes Creek line, constructed by Dominion Energy, began supplying power to 600,000 people on Virginia’s Lower Peninsula in February.

Assessing the environmental impact of a project that has already been completed is a situation new to the U.S. Army Corps of Engineers.

But in this case the agency has no choice.

On March 1 the U.S. Court of Appeals for the District of Columbia ruled that the corps’ earlier finding that the transmission line would have “no significant impact” on the surrounding environment was “arbitrary and capricious” and ordered it to conduct an environmental impact statement.

“Congress created the EIS process to provide robust information in situations precisely like this one, where, following an environmental assessment, the scope of a project’s impacts remains both uncertain and controversial,” the court declared in its opinion.

An in-depth review that incorporates public feedback and variables including air and water quality, economics, energy needs and cultural resources, an EIS also considers alternative ways of executing a project — in this case, 27 other ways.

But the process is designed to occur during the planning stage of a project, not after the work is done. And because of that, using it to evaluate the Surry-Skiffes Creek question has itself proved “uncertain and controversial.”

“We can’t ignore reality, but at the same time we have to be careful in how we use information,” said William “Tom” Walker, chief of the regulatory branch for the corps’ Norfolk division.

The primary issue is whether the existing line should be considered a variable in calculations of economic and environmental impact or whether the calculations should be done as they would have before the line was built.

It’s not an esoteric question: incorporating the cost of demolishing the line into economic assessments of other alternatives could sway the study’s outcomes. In that case, keeping the line in place would be virtually a foregone conclusion.

Still, said Walker, “it is a real impact. So we’re going to have to think about that.”

Groups like the National Trust for Historic Preservation have taken a more hardline stance. Most of them believe that the towers should never have been built, that the line should come down, and that an assessment of impact should not take into account the fact that the line already exists.

“The baseline should be a review as if the project had never been constructed,” said Sharee Williamson, associate general counsel for the National Trust for Historic Preservation, which, along with the National Parks Conservation Association and several other organizations, is behind the lawsuit that led to the U.S. Court of Appeals’ March 1 decision. “That is what the [National Environmental Policy Act] requires.”

Elizabeth Kostelny, chief executive officer of Preservation Virginia, also argued in favor of evaluating all of the alternatives as if the line had never been built but instead pointed to the U.S. Court of Appeals’ ruling as justification. That decision, she said, “infers … that the baseline is no powerlines.”

If the corps does adopt that baseline, Pam Goddard, senior mid-Atlantic program director for the parks conservation association, said she is confident that other alternatives will be shown to be better options than the Surry-Skiffes Creek line, which is estimated to have cost $435 million.

“On cost alone we think that there are some alternatives that will be cheaper,” she said — not to mention less destructive of environmental and historic resources.

But Dominion is holding firm to its stance that the existing Surry-Skiffes Creek line is the best option for supplying the Lower Peninsula with power.

“We think the Army Corps did an excellent job assessing the environmental impact,” said Dominion spokeswoman Bonita Harris. But in the meantime, “We’re happy to cooperate with them as much as we can.”

Goddard counters that the parks association does “not feel like the corps is holding the open process” it is required to, particularly with regard to gathering public input. The agency published its notice of intent to prepare a draft EIS in the Federal Register on June 21, with a comment period lasting until Aug. 1 — a short window that Goddard said “just does not give us a lot of confidence.”

The group has filed a request to extend the comment period, and the corps said that it is considering the possibility. But Mark Haviland, chief of public affairs for the agency’s Norfolk district, said the corps also doesn’t view Aug. 1 as a hard deadline for input.

“We’ll consider comments whenever they come in,” he said. “This is the beginning of a process that’s going to last for a very long time.”