Bacon's Rebellion

Landfill, Recycle or Close in Place?

Coal ash disposal underway at Dominion’s Possum Point Power Station. Photo credit: Dominion Virginia Power

Executives at Dominion Virginia Power thought they were being good corporate citizens a year ago by acting quickly to implement Environmental Protection Agency regulations governing the disposal of coal ash. When the EPA published its new rules, the electric utility promptly announced plans to create a long-term storage solution for the containment ponds at its Bremo and Possum Point power stations.

The EPA had enacted the rules in response to the rupture of a Tennessee Valley Authority coal ash pond in 2008 and a spill from a Duke Energy facility in 2014, both of which caused extensive contamination of nearby rivers. The incidents sparked national outrage and stoked demands for measures to prevent another disaster. The fixes that Dominion detailed in its requests for waste-water and solid-waste permits put the company on the fast track to eliminate any chance of a spill from either power plant.

But the power company is not feeling the love. Environmental groups have contested company plans on the grounds that they would not prevent traces of heavy metals from leaching into the groundwater and eventually into rivers and streams. Denouncing Dominion for ravaging the environment, protesters marched on the state capital. Every other day seems to bring another controversial headline.

Rob Richardson, a Dominion spokesman on the coal ash issue, expressed the bewilderment felt by many within the utility. Dominion has been forward-thinking on coal ash, he said. While other companies submitted plans in late November 2016, Dominion unveiled its plans late in 2015. Instead of winning praise and moving expeditiously through the permitting process, the company has been subjected to an endless litany of criticism. Said Richardson: “We’ve been taking a beating.”

Environmentalists have moved beyond the original goal of stabilizing the coal ash. Through lawsuits, press releases and news stories, critics have changed the terms of debate. Dominion may be solving one problem — the threat that breaking levies might send large volumes of slurried coal ash spilling into the James or Potomac rivers — but critics says its plans to consolidate the coal ash in existing, unlined containment pits won’t halt the leaching of heavy metals into the groundwater.

The company did act quickly, but only to take advantage of a loophole in the EPA rule that allowed utilities to close “inactive” ponds with fewer monitoring requirements, says Greg Buppert, a Southern Environmental Law Center (SELC) attorney who has represented the Virginia Chapter of the Sierra Club and local river-keeper organizations in lawsuits against Dominion. The EPA has since eliminated that loophole.

“Dominion is ignoring an emerging industry standard in how utilities are dealing with these ash ponds,” he says. “Throughout the region, utilities are excavating unlined ponds, putting the ash in landfills, and in many cases recycling the coal ash.”

Stung by charges that it isn’t living up to the standard set by other utilities, Dominion recently released data culled from EPA filings. In truth, the company says, its closure practices fall well within the norms of the electric-utility industry. Only a minority of coal ash ponds are being landfilled. Many are being closed in place, as seen in the chart below.

Number of coal ash ponds, by company, that are being closed in place. (Click for more legible image.)

Atlantic Coastal Plain. Image source: Wikipedia

But the chart doesn’t come close to settling the debate. Buppert counters that industry-wide comparisons aren’t relevant. Dominion’s power plants are located in the Atlantic Coastal Plain, a low-lying area where groundwater lies close to the surface. Hydrological conditions are different there than in the Piedmont and mountain regions where many coal plants are located. Utilities in the Carolinas and Georgia have agreed to landfill and recycle their coal ash rather than bury it in pits. Dominion has proposed instead to consolidate its coal ash in unlined pits — one at Bremo and one at Possums Point — and cap them with polyethelene lining and a two-foot layer of dirt. Dominion’s proposal, he argues, does not prevent groundwater from migrating through the pits and picking up leached metals from the ash.

In turn, Dominion argues that comparing its power plants to those of Duke Energy, Santee Cooper, Georgia Power and SG&E (SCANA) on the basis of superficially similar hydrology is flawed thinking. Each power plant is unique. Each site has distinctive topographical and hydrological features. Measures that make sense for one site don’t necessarily make sense for another.

Dominion insists that its approach protects the environment without the huge expense of landfilling the coal ash, which could run up the cost to $3 billion. Furthermore, trucking the coal ash to a landfilled location would take many years to complete, leaving the public little safer from potential spills during the interim than they were before. Indeed, literally thousands of truck trips through residential areas would elevate the risk of traffic accidents while diesel fumes and dust pose a nuisance and health risks.

Who’s right? It gets complicated. Strap on your face mask and buckle your scuba tank for a deep dive into the arcane discipline of coal ash disposal.


Coal ash, known formally as Coal Combustion Residuals or CCR, is the finely grained mineral material left over from the combustion of coal in electric utility boilers. For decades, utilities placed the ash in containment pits and mixed it with water to prevent the dust from blowing away. Typically, rain water accumulated on top of the coal ash, creating a pond.

The new EPA guidelines outline two steps. The first is de-watering the coal ash, which requires a waste-water permit to release the water into a river or stream. The second entails creating a permanent place to store the de-watered coal ash, which requires a solid-waste permit.

Dominion is in the process of de-watering the coal ash at its Bremo and Possum Point power stations. Water drained from the ponds runs through an elaborate filtration process to extract heavy metals and other potentially toxic compounds. The state’s Department of Environmental Quality has set contaminant limits for the water released into the James River and Quantico Creek. Normally, the contaminants pose no threat to human health or aquatic life except in a small mixing bowl where they are diluted by fresh river water. In extreme drought conditions, the mixing bowl could extend plume-like miles down the river. But Dominion spokesman Dan Genest says the water released into the water at Bremo is so clean that for “all intents and purposes” there is no mixing zone at all.

Most of the issues associated with de-watering have been settled at Bremo and Possum Point — the treatment and monitoring standards were tightened after negotiations with environmental groups — although discussions continue at Dominion’s Chesterfield Power Station and the Chesapeake Power Station.

The new round of controversy centers on what to do with the coal ash after the water has been removed. Broadly speaking, the EPA allows two options. The first is “capping in place.” Dominion proposes consolidating five ash ponds at Possum Point into one impoundment basin. The company then proposes covering each basin with an impermeable polyethelene liner and two feet of topsoil, enough to support vegetation.

The second option is to “landfill” the coal ash, either on-site if there is enough acreage to create a landfill, or off-site. The landfill option is significantly more expensive than the capping-in-place alternative because it requires utilities not only to apply a polyethelene cap, but to place a liner on the bed and sides of the pit as an extra layer of protection against groundwater coming into contact with the ash, and also to install a leachate collection system to divert any water that might make it through. Dominion estimates that landfilling all of its coal ash would run up the tab for disposal from about $500 million to $3 billion.

A variant of the second option is to “recycle” the coal ash, usually as a replacement for cement in concrete or an additive to cement. The concrete-making process binds the ash and its heavy metals with other compounds and renders them chemically inert. Environmentalists consider recycling to be a permanent and desirable solution.


Jason Williams, Dominion’s environmental manager, contends that capping in place is the safe and relatively inexpensive option at Bremo and Possum Point. “The best thing to do,” he says, “is to get the water out, and get these things capped and sealed up.”

While Dominion has decided to use cap-in-place at its Bremo and Possum Point plants, the economic and engineering logic varies from location to location depending upon the size and shape of the real estate parcel, topography and hydrology. The company has not yet announced how to deal with coal ash at its Chesterfield facility on the James River or its Chesapeake plant on the Elizabeth River.

At Bremo and Possum Point, says Williams, the company didn’t have the space to build a landfill to meet EPA’s requirements for setbacks from the river. Landfilling would have required building a facility off-site, which in the case of Possum Point would have entailed moving nearly half a million truckloads through a residential neighborhood. “If we excavated,” he says, “we’d be doing it for the next 19 years.” EPA requires the ponds to be closed within 15  years.

Buppert with the SELC notes that Possum Point also is served by rail. While trucks carry only 15 tons, railcars can transport 90 to 100 tons each. At Duke Energy’s Sutton site, an 85-car train leaves twice a week with about 8,000 tons. Dominion has examined rail as an alternative to trucks at Possum Point but has not made public its findings.

Just because it makes sense for Duke to use rail, Dominion cautions against comparing one power station to another. Does a site require construction of a loading facility? Is there space to hold enough cars to comprise a train? Is there a recipient for the coal ash along the rail line, and does it have a facility for the material to be off-loaded? How much would these facilities cost to build, and could they be built in time to meet EPA deadlines?

The fact is, Williams argues, cap-in-place is perfectly acceptable. At Possum Point, the impoundment pond is lined with clay, which, though not as impermeable as polyethelene liners, limits the flow of groundwater. And even that may be redundant because groundwater will not migrate through the coal ash depositories, either there or at Bremo. “All the data we’ve seen so far shows a clear separation from the bottom of the pond and the top of the groundwater.”

As long as the coal ash is situated above the underground water table and as long as there is a polyethelene cap to prevent rainwater to percolate through, there is no way for the groundwater to get contaminated. But just in case, EPA regulations require Dominion to maintain monitoring wells around the containment pit for thirty years. If there is any sign of contamination in the test wells, EPA rules require Dominion to redress it.

“As a general matter, if the impoundment has removed the hydraulic head (the rainwater atop the coal-ash slurry), removed the discharge into the receiving stream, and put a cap on it, you have greatly reduced the chances of something bad occurring,” says Richard Kinch, a retired chief of the Industrial Materials Reuse Branch of the EPA. “You’ve addressed the greatest drivers of significant risk.”

An EPA analysis of groundwater contamination at unlined landfills found that groundwater would not pose significant risk at 80% of the sites modeled for a 10,000-year period. However, there was a  significant risk for 20%. Says Kinch: “That’s why individual circumstances need to be evaluated — the depth of the groundwater, local rainfall, hydraulic conductivity, and presence/influence of a nearby water body.”


SELC thinks Bremo and Chesterfield fall in the 20% category. Using Dominion’s own maps, Buppert says, he can demonstrate that parts of the coal pits do intersection with underground water tables. Water will migrate through and pick up contaminants.

Below appears an image based upon a Dominion document that shows a cross-sectional profile of the Bremo containment pit. The yellow line shows the depth (in feet above sea level) of the impoundment pit. The red oval shows where the depth descends as deep as 260 feet above sea level.

Cross-section of Bremo coal ash impoundment.

The map below, also based upon a Dominion document, shows a top-down look at the coal ash ponds at Bremo along with the contours of the underground water (blue dashed lines). Water flows perpendicular to the contour lines toward the James River (seen as a broad stripe). The  yellow oval marks where the water table drops from 306 feet in elevation to 255 feet.

Groundwater contour map of Bremo coal ash impoundment.

In summary, the first map shows that the coal ash deposit descends to a depth of 260 feet above sea level at roughly the same spot that the second maps shows groundwater is migrating from 306 feet above sea level to 255 feet. That, says, Buppert, is a significant overlap and a point at which the coal ash likely would contaminate the water flowing into the river.

Dominion documents also suggest that coal ash is in contact with groundwater at the Chesterfield site as well, Buppert says. “We think these documents contain information that allows us to draw the conclusion that ash is in contact with groundwater at these sites.”

Not necessarily so, says Dominion’s Williams. “With all pond closures the removal of surface water will likely have an effect on the surrounding subsurface water levels as the hydrology of the immediately surrounding area will change,” he says. “As such we are continuing to evaluate and study the groundwater elevation surrounding our ponds. Our closure plans will accommodate for whatever groundwater scenarios those evaluations reveal in full compliance with the closure performance standards included in the CCR Rule.”


Buppert argues that Dominion should store the coal ash in state-of-the-art landfills built with clay liners, polyethelene liners and leachate collection systems. Other Southeastern utilities in the Atlantic Coastal Plain are adopting this approach, often adding a recycling component to reduce the volume of coal ash that needs to be landfilled. Dominion should do the same, he says.

Representing the Sierra Club in a case against Dominion, the SELC noted that Dominion “stands alone” with his closure-in-place plans. An SELC brief noted the following:

“In sum, says the brief, “every utility in North Carolina, South Carolina, and Georgia has agreed to excavate multiple coal ash impoundments across multiple sites; and every coal ash impoundment situated in the Atlantic Coast Plain physiographic province is being excavated.” Cumulatively, Southeastern utilities are recycling or placing in dry, lined storage more than 75 million tons of coal ash, Buppert says.

Sources contacted by Bacon’s Rebellion confirmed that the utilities cited by SELC utilities are relying heavily upon recycling and landfilling, but said there are exceptions. And they stressed that each situation is unique, and that the optimum solution varies from location to location.

Santee Cooper has been recycling dry ash (directly from the boilers, also referred to as fly ash) for years and had built up good relations with companies that took the ash. Now it plans to recycle much of the wet ash (stored in ponds). “We expect to recycle as much of the ash as we can,” says spokeperson Mollie Gore. “We would be happy if it can all be beneficially reused, but a small amount most likely will be landfilled.”

One advantage Santee Cooper has is the availability of land site to build the recycling facilities that process the ash by separating out unburnt carbon. “The companies that take our ash are very close to our generating facilities,” says Gore. “Transportation is a huge, huge expense. … This is not a solution that makes sense for everybody. It makes sense for Santee Cooper because of the proximity of the vendors.”

Duke Energy did not make any of its officials available to Bacon’s Rebellion for an interview, but it did provide coal ash fact sheets. The documents indicate that the company is closing 34 ponds by removing the coal ash but is closing 18 others in place. Regarding the options provided by state and federal law, Duke states: “Excavation [and landfilling] may be appropriate for certain technical reasons, such as a basin located in a flood plan. Each basin is unique, and the closure plan will be customized to the site to ensure it is most effective.”

“The cheapest option is cap-in-place. That’s known,” says David Wright, a former South Carolina public service commissioner. “Everybody is all concerned about the cost and impact on ratepayers. … It would be nice to make [the coal ash] all go away. But if the cost is prohibitive, there’s a balance that needs to be struck. … There’s not just one answer.”


Aside from transportation issues, the driving variable in the decision whether or to landfill coal ash is the ability to recycle the material. By reducing the millions of tons that must be landfilled at great expense, recycling tips the economics in favor of landfilling over closure in place.

The primary consumer of coal ash is the concrete industry. About half the concrete in the United States contains fly ash, which is added to improve durability. Bottom ash is recycled for use in concrete blocks, and another coal ash residual, synthetic gypsum, is used to make wallboard. Boiler slag is often used as a sand-blasting media.

Coal ash is not a uniform product, says Kinch, the former EPA manager. Certain classes of coal produce an ash that is more appropriate for use in concrete.  If the residuals contain too much carbon that didn’t combust in the boiler, the material will not be useful in concrete unless a secondary treatment process removes the carbon. The expense of processing varies depending, among other factors, upon how far the power company must ship the material. Locating a processing plant nearby reduces trucking costs.

Wet ash from surface impoundments is different from dry ash coming directly out of the power plants, says Kinch. Lengthy exposure to water creates a less desirable coal ash for use in concrete. Wet ash can be effectively treated, but that requires an extra processing step, which adds extra expense. “To the extent that the market has leeway to absorb additional use,” he says, “the market will favor the additional supply of newly generated dry ash.”

Another factor affecting the economics of recycling the is availability of other additives such as ground-granulated blast furnace slag, a byproduct of iron and steel making. If there are blast furnaces nearby, blast furnace slag can compete with coal ash.

Market conditions vary from state to state. “There is a tremendous coal ash market in Virginia that is grossly under-served,” says Hank Keiper, Mid-Atlantic area manager for the SEFA Group, which provides coal-ash beneficiation services. The Virginia Department of Transportation requires either coal ash or blast furnace slag in the concrete used in road and highway construction.

“Slag cement is imported into New Jersey and Maryland, then trucked into Virginia,” Keiper says. “All fly ash used in concrete is imported from other states.  There are no in-state sources of concrete-grade fly ash in Virginia currently.”

However, Dominion paints a different picture of the market for coal ash in Virginia. Bill Murray, Dominion’s manager of public policy, says Dominion recycles about 700,000 tons a year of residuals from its four coal-burning power plants. Based on the volume of ash stored at the Chesterfield facility and the current projections of the concrete ash grade market, it could take 40 to 60 years to recycle the ash at just the Chesterfield facility.

A bill proposed by state Sen. Scott Surovell, D-Fairfax, would require owners of coal ash ponds “within the Chesapeake Bay watershed” to evaluate the feasibility of recycling and landfilling as an alternative to closure in place. Such assessments would be transmitted to the General Assembly. A compromise version in the House of Delegates deleted the requirement that the information be compiled before the state issues waste-water permits allowing the ponds to be closed.

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