Today, Virginia Dominion Power is set to begin the process of treating and releasing about 220 million gallons of water from its coal-ash ponds into Quantico Creek, and eventually into the Potomac River, an endeavor that will cost $35 million and take nearly a year to complete.
During a two-hour media tour of the Dumfries-area power plant last Tuesday, Dominion officials detailed the water-treatment facility they’ve assembled near the banks of “pond D,” the largest of five holding ponds the utility has used to store coal ash, a byproduct of burning coal to make electricity.
Dominion hasn’t burned coal at Possum Point since 2003. The power plant is located just outside of Dumfries on the Possum Point peninsula, so named because it’s shaped like a possum’s head. The plant now burns only natural gas.
But Dominion must clean up an estimated 200,000 cubic yards of coal ash that has accumulated at the plant since it opened in 1948. As was the industry standard, the ash was dumped in pits and covered with water to keep it from becoming airborne.
Massive coal-ash spills in Tennessee and North Carolina in recent years prompted new federal rules requiring power plants to drain and close coal-ash ponds around the country.
The process has sparked protest from environmentalists, who worry water seeped in coal ash will pollute receiving waterways, threatening fish, aquatic life and possibly groundwater-fed drinking wells. Coal ash contains a mix of toxic heavy metals, including arsenic, lead, boron, selenium, chromium and hexavalent chromium.
Dominion officials say the onsite treatment process is “state of the art” and will clean the water beyond what is required by the controversial permit modification Dominion received from the Virginia Department of Environmental Quality in January.
“For those of us here at the station, this a personal project,” said Cathy Taylor, Dominion’s director of electric environmental services. “We live in the community. We drink the water from the river. We boat and fish in the river. … It’s very important to us that we do this right.”
Water from the ash ponds has mostly been consolidated into one pond, “pond D,” but also remains in the ashy sludge in the plant’s other four ash ponds – A, B, C and E – which will also be pumped into the treatment system.
Operated by Michigan-based ProAct Services Corporation, the system is designed to treat both the less-contaminated surface water and the more heavily-contaminated “pore” water, which is commingled with the ash, said Jason Williams, a Dominion environmental manager.
The treatment system spans about 900 yard and includes nine steps. The water is first piped into four aeration tanks, which begin the process of separating out the coal ash contaminants. In the second and third steps, the pH is reduced to induce further separating, and two chemicals are added to bind the coal ash constituents together.
The water then passes through two filtering steps, during which the coal-ash constituents are collected in truck-sized “geobags” that will be hauled away to a landfill in King George at a rate of a few truckloads per week, Taylor said.
The water is then tested and processed through an “enhanced treatment” process if necessary.
Finally, the pH is adjusted back up to levels considered safe for the river and held in two 100,000-gallon holding tanks, where it will undergo another round of tests to determine if it meets the more stringent constituent limits Dominion promised Prince William County officials in a March agreement that kept the county from challenging the utility in court.
Taylor said the agreement did not substantively change Dominion’s treatment process but rather that Dominion officials better explained their plans to win the board of supervisors’ approval.
“It clearly defined in writing what standard we were going to use, what number we were going to use for turning on the enhanced treatment,” Williams said. “So it was an effort in being transparent in communicating with the county.”
The State of Maryland, which has jurisdiction over the river, and the Potomac Riverkeeper Network are still fighting Dominion’s permit to dewater the ponds in court.
Potomac Riverkeeper Dean Naujoks said Dominion is not using “the best available technologies” to treat the water, as is required by federal law. North Carolina, for example, requires more stringent limits on arsenic in treated coal-ash water. The Riverkeeper Network also objects that the treated water will be tested by contractors paid by Dominion.
“We have to trust that what Dominion is doing is good enough for Quantico Creek and for the Potomac River,” Naujoks said.
Williams emphasized that the treated water would be held in tanks until testing by two outside vendors – GAI Consulting and Pace Laboratories – confirm it is safe enough to be released into the creek. If any of the constituents exceed Dominion’s agreed-upon limits, the water can be retreated, Williams said.
“So we have the ultimate fail-safe with having those [holding] tanks in that we recollect that water and make sure, absolutely, that everything that leaves here has been tested by a third-party, verified and safe for Quantico creek,” Williams said.
The water will be tested hourly, and the results will be posted on the Dominion website.
Once the process begins, the water will be treated around the clock, with 16 to 20 workers manning 12-hour shifts until the ponds are adequately drained, which is expected to occur by May 2017.
Dominion hopes to proceed with the pond closure plans by burying the dewatered coal ash in pond D, which has a packed, natural-clay liner. The pond will be topped by a synthetic liner, two feet of dirt and vegetation. Dominion has said it will monitor the pond for leakage for at least three decades.
To proceed with those cap-in-place plans, however, Dominion will need to obtain a separate DEQ solid waste permit. That, too, is expected to be opposed by environmental groups who say toxic coal ash should be moved to synthetically lined landfills away from rivers and major waterways.