A federal judge ruled Thursday that Dominion Virginia Power’s storage of coal ash at a now-closed plant near the Elizabeth River has been illegally polluting groundwater and the river for years. The decision could impact Dominion’s plans to permanently store ash in pits at other plants where coal has historically been burned for power.

U.S. District Judge John Gibney Jr. in Richmond ruled that the Sierra Club had proved that arsenic from four coal ash impoundments at Chesapeake Energy Center has contaminated groundwater and seeped into the Elizabeth River. In a 21-page opinion, Gibney wrote that the pollution violates the federal Clean Water Act because the company did not have a discharge permit from state regulators for such releases.

But the judge did not immediately require Dominion to excavate the pits that he ruled have been leaking. Rather, he is requiring Dominion to perform additional testing and has asked both sides to submit briefs outlining their preferred remediation plans within 30 days. He would like to see the two sides agree on what to do, but if they cannot, the judge said he would decide based on their suggestions. 

Overall, the judge’s decision was a mixed bag for both parties, with each declaring victory in some aspects. 

“We’re pleased the court agreed Dominion is breaking the law because its coal ash is polluting the Elizabeth River, but we are disappointed the court did not order a full cleanup,” said Deborah Murray, lead attorney on the case for the Southern Environmental Law Center, which represented the Sierra Club.

The Sierra Club had asked the judge to require Dominion to excavate and remove the more than 3 million tons of ash in four pits at the site to a lined landfill. Murray said she was still digesting the judge’s decision, but that he seems to want the two parties to reach a compromise in a suggested remediation.

Still, she said, “it is not a viable option to leave the pollution source in place and allow the pollution to continue.”

Dominion spokesman Rob Richardson said in a statement that the company was pleased with parts of the judge’s decision, including comments in his opinion that removing the ash from the site would not be in the “public interest” because it would “entail years of efforts costing hundreds of millions of dollars, for little return.”

Dominion added in the statement that requiring such action would result in higher electric rates for customers. Murray, though, said the company did not present any evidence on the potential cost to ratepayers at the trial.

Gibney ruled that the company would not be required to pay civil penalties for violations of the Clean Water Act, stating in his opinion that “Dominion should not suffer penalties for doing things that it, and the Commonwealth, thought complied with state and federal law.”

The judge did declare the four coal ash “piles” at the site to be “point sources” of pollution under the Clean Water Act, rejecting Dominion’s argument that the facility was too large to be considered a single source of contamination. His opinion did not seem to distinguish between ponds that were lined or unlined. The plant in Chesapeake, VA, does have two permits from the state to discharge wastewater from the site, “but neither authorizes the utility to release discharges into groundwater” or to discharge arsenic, the judge wrote in his opinion.

Arsenic is a naturally occurring element, but it's also an ingredient in coal ash. If ingested at high doses, it can cause death; lower levels of exposure can cause a variety of health effects. Many common arsenic compounds dissolve in water, and can wind up in bottom sediment. Fish and shellfish can accumulate arsenic, though much of it is in an organic form that is less harmful, according to the U.S. Agency for Toxic Substances and Disease Registry. 

Legal experts have said they think the case could affect how Dominion and other power plant owners go about closing other impoundments they have used for decades to hold the ash residue from burning coal for power.

Patrick Parenteau, an environmental law professor at Vermont Law School, said that the case deals with a longstanding subject of controversy on which courts are still divided: whether the Clean Water Act applies to pollution from groundwater.

“It is important that a court has now said definitively that discharges from coal ash impoundments via groundwater to surface water are discharges requiring a permit under the Clean Water Act,” he said. “I think it’s an important precedent from that standpoint.”

Robert Percival, director of the environmental law program at the University of Maryland Law School, called the ruling a “significant victory” for the environmental groups, even if the judge was cautious about ordering a remedy.

“The decision suggests that Dominion will be held responsible for stopping the pollution,” he said, “and that decisions concerning Dominion’s solid waste permit and others’ in similar situations will have to take into account potential impacts of groundwater pollution on surface waters.”

Dominion is currently seeking a solid waste permit from the state to permanently store ash at its Possum Point power plant near the Potomac River in Quantico, VA, and a decision was expected in June.

But on Wednesday, Virginia Gov. Terry McAuliffe amended a recently passed bill dealing with coal ash, restoring a provision imposing a year-long moratorium on ash-related permits and requiring the company to make more information about alternative disposal options available to the public. The measure will need to be approved by the General Assembly in early April.

Murray said the judge’s decision did establish that the Clean Water Act applies to groundwater, which could have implications for other coal ash storage decisions in the state and beyond.

“This has established the principle that, in this court in Virginia, the Clean Water Act covers discharges to surface water by means of hydrological connections via the groundwater,” Murray said.

Dominion’s own groundwater monitoring reports to the state Department of Environmental Quality about the Chesapeake site were used in the case to show that arsenic, along with other contaminants, had been leaking from the pits for more than 30 years. DEQ did require Dominion to take “corrective action” because of the groundwater pollution, but the judge found that was not sufficient.

The court found that Dominion’s solution of “monitored natural attenuation” — which relies on natural dilution to reduce too-high concentrations of contaminants in the groundwater over time — “does not adequately address the discharge of arsenic.”

The judge equated the two parties’ suggested remediation for the problem as an “all or nothing approach: all (the Sierra Club’s scheme of moving the ash), or nothing (Dominion’s MNA plan).”

Dominion’s Richardson said the company is evaluating additional groundwater treatment options for the site, “including technologies that would treat any impacted groundwater at the property boundary,” for consideration.