The Big Cleanup
Work starts on closing contaminated ponds at power plant
CHESTER — A massive and costly project to clean up millions of gallons of contaminated water at Dominion Energy’s Chesterfield Power Station got underway in earnest on Tuesday and is set to continue for the next year and a half.
Preparations for the project to eliminate ponds that store water contaminated with coal ash at the Richmond-based electric utility’s largest remaining coal-fired power plant have been going on for months. Work already done includes the installation of a complex network of
state-of-the-art water filters and chemical treatment devices, and six tanks that will each hold 950,000 gallons of purified water until the water passes final testing and can be released into the James River.
Dominion Energy spokesman Robert E. Richardson said the project represents more than just the cleanup of the coal ash ponds on the company’s property at Dutch Gap, though that will be a major undertaking – the two ponds combined hold about 15 million cubic yards of coal ash and 200 million gallons of water.
More significantly, Richardson explained, the project will completely change the way the company moves and disposes of residue from the power station’s four huge coal-fired generators, which have a combined capacity of nearly 1,300 megawatts and provide electricity for 12 percent of Dominion’s customers.
Producing that much power by burning coal creates a lot of ash that has to be removed from the generators. The
method used for most of the more than 70 years the Dutch Gap plant has been operating has been to "sluice" the ash down to the ponds with water – about 6 million to 8 million gallons a day at present, Richardson said.
Keeping the ash wet does help prevent dust from getting into the air, but it also has the potential to cause major environmental problems. In just the past decade, two spills at Tennessee Valley Authority power plants released more than 5 million cubic yards of coal ash into waterways in Tennessee and Alabama, while a spill at a Duke Energy plant in North Carolina released some 27 million gallons of contaminated water into the Dan River.
Over the years, coal ash has been recycled routinely into a variety of products and uses, including Portland cement, concrete and landscaping fill. However, health concerns have mounted due to the presence in coal ash of toxic substances such as arsenic and heavy metals.
All of these issues have led the U.S. Environmental Protection Agency to rewrite the rules for disposal and storage of coal ash, and Dominion was going to have to make upgrades under the new rules. But Richardson said the company has decided not only to comply with the changes, but to go beyond them in cleaning up the ponds and changing its processes to create "an enhanced positive impact on the environment."
Like other utilities, Dominion has been moving away from using coal as fuel for its generators, switching to natural gas at most of its generating stations. For example, the two newest of the six generators at Dutch Gap burn gas. But even at the stations where the company has converted completely to gas, major amounts of ash remain, and the company is working on eliminating those legacy deposits in much the same way as it's dealing with the issue in Chesterfield.
Currently, Dominion has closed or is in the process of closing all of its remaining coal ash ponds – five at the Possum Point Power Station in Prince William County, three at the Bremo Power Station in Fluvanna County and one at the Chesapeake Energy Center in Hampton Roads, in addition to the two at Dutch Gap.
The coal ash that's left in the existing ponds will be compacted and covered with a synthetic liner and two feet of soil to prevent rainwater from reaching it and causing it to leach contaminants into the groundwater. Going forward, ash created in the generating process will be trucked to a new, state-of-the-art lined landfill the company is building on the power station property.
The new dry disposal process will eliminate the need to use 6 million to 8 million gallons of water a day to sluice the ash out of the generators, and the company is also building a new water treatment plant at Dutch Gap to handle the relatively small amount of wastewater the power plant will be producing in the future.
All of this will come at a price, of course — the "de-watering" process alone will run about $2 million a month over the next 18 months, according to Richardson.
More information on the coal ash pond closings is available on Dominion's website at www.dominionenergy.com/about-us/ electric-projects/coalash-pond-closuremanagement
Ginger Phelps, a generation construction project manager at Chesterfield Power Station, walks through a temporary water treatment system used to treat coal ash pond water as the plant phases out their coal ash ponds, during a media tour on Monday, Nov. 13, 2017.
A 30-day supply of coal, at right, is piled and ready for burning at the Chesterfield Power Station in Chester on Monday, Nov. 13, 2017.
Jason Williams, of power generation operations at Chesterfield Power Station, walks through the room of six turbine generators at the power plant that generates 12 percent of the electricity for all Dominion Energy customers, during a media tour on Monday.