How North Carolina law could make it harder to recycle coal ash

This article was originally published by Southeast Energy News and is republished here with permission. The article was written by Coal Ash Chronicles’ director Rhiannon Fionn.

Deadlines in North Carolina’s coal ash law have some worried that Duke Energy may choose recycling options that could leave prospective concrete customers unsatisfied and much of its coal ash inventory in wet impoundments.

Henry Batten, president of Concrete Supply Co. in Charlotte, says he is committed to buying Duke Energy’s recycled coal ash even though he says it will cost him more than purchasing imported Asian ash. However, because of state law, he questions whether Duke Energy can choose to build the type of reprocessing plant that produces ash that, he says, “is 100 percent consumable by us without question; in fact, I would take it all day, every day if I could get it.”

Citing geopolitical concerns, he says having a regional source of coal ash that meets international and state specifications for concrete is critical for his company. But his preferred process for beneficiation – optimizing the ash for use in concrete — is the most expensive, and Coal Ash Management Act (CAMA) deadlines don’t seem to leave room for facilities with long enough lifespans to justify the investment.

Between its North and South Carolina operations, Batten reports that his company “consumes about 2.1 to 2.5 million tons of ash annually,” adding, “I’m probably the largest consumer of ash in the Carolinas, and I made a commitment that I would buy that ash because I need a reliable source.”

Batten made his comments during a presentation to the Alliance of Communities Together (ACT) Against Coal Ash group.

“We feel like the better informed we are, the better we can make decisions, and the better we can advocate for those people who will be most affected,” says, Caroline Armijo, a member of ACT, who says she never imaged herself advocating for the concrete industry.

Duke’s options
North Carolina law requires Duke Energy to create three beneficiation plants capable of annually producing 300,000 tons of ash “to specifications appropriate for cementitious products” from wet waste impoundments.

The law also requires the company to announce siting for two of the three plants by Jan. 1, 2017, and a third by July 1, 2017. In October, as part of a lawsuit settlement, Duke identified its Buck plant, in Salisbury, North Carolina, as one of the three sites.

The company could go with one or more of multiple options at the two additional plants, and those options could be provided by different vendors; the technology used at each plant could vary since the technology selected must be site-specific.

The associated costs range from less than $5 million for dry-ash-handling only to more than $50 million for thermal beneficiation that can process both wet and dry ash. It’s the latter that produces the quality of ash Batten wants for his concrete company.

A market study, to be presented to the North Carolina Environmental Management Commission on Nov. 9, states, “To our knowledge, the only large scale commercial operation in the U.S. that is currently processing wet ash is the SEFA STAR process.”

Another company, PMI Ash Technologies, based in Raleigh, is listed as a thermal beneficiation company for dry ash using its Carbon Burn Out process, but CEO Lisa Cooper says her company is also qualified to handle wet ash.

Both she and Jimmy Knowles, Vice President of Market Development and Research at The SEFA Group, headquartered in Lexington, South Carolina, say that the $50 million price tag represents the high end of the price range for thermal facilities at large coal-fired plants, but that it’s not an unreasonable estimate.

“The cited all-in cost above would be for a large plant, probably with a maximum feed rate approaching 500,000 tons per year,” says Knowles. “The design for an ash beneficiation plant at any of the Duke Energy sites in N.C. would probably be similar in size.”

Cooper says the price estimate likely includes storage, an important consideration during winter months when there is less construction activity. She says storage costs could be mitigated through agreements with ash marketers.

A site’s location could also drive beneficiation costs up. “We have a nice plant in Georgetown, South Carolina,” says Knowles, “but between the seismic zone it’s in and hurricane issues, there were all kinds of additional costs that were built into it that increased the costs.”

Duke Energy could also save by mixing and matching its options, installing the more expensive, but smaller-scale, thermal option along with less expensive dry-ash processors, enabling its ability to upgrade or expand its ash processing in the future in response to market conditions.

The company has only begun the process of requesting information from the companies and declined to comment on vendor-related matters.

Duke could be competitive on coal ash

The market study, produced by Electric Power Research Institute (EPRI), the University of Kentucky Center for Applied Energy Research and Golder Associates, indicates that Duke Energy is well positioned to turn coal ash into a revenue stream with its “competitive advantage” in North Carolina. The study also noted that Duke might be competitive in several other states as well and that annual demand for coal ash is increasing.

In fact, demand is so high that Batten says the controversial “cap-in-place” closure method isn’t a deterrent. Capping an impoundment, however, would add to closure expenses.

“We would hope that every plant that ever gets capped would eventually allow us, or someone like us, to harvest that ash for reuse in concrete because it’s better – it’s a more sustainable option than leaving it in the impoundments,” says Batten.

“We are exploring how cap-in-place designs can be used to allow for potential coal ash recycling,” says Duke Energy spokesperson Zenica Chatman, adding that in Florida the company is harvesting previously capped ash to meet market demand there.

North Carolina ratepayers could pay for the beneficiation plants, but they could also benefit from them.

Currently, according to Chatman, “The company does not profit from ash sales in North Carolina. If we have a profit in the net sale of ash byproducts, North Carolina customers get the benefit. If we have a net loss, the company may recover the losses through the fuel clause.”

Deadlines not beneficial
According to the study, “Beneficiation will be most attractive at those facilities that will eventually require excavation of the ponded ash, do not have an alternative use (e.g. clay mine fill), and have a minimum 15 to 20-year period to evaluate, design, construct, and operate a beneficiation facility.”

Deadlines were mentioned as an impediment, however, though the 2016 law allowsthe secretary of the Department of Environmental Quality to extend the deadlines.

Currently, the deadline for closing intermediate-risk impoundments is August 1, 2028, and the deadline for closing impoundments at plants with beneficiation processing is Dec. 31, 2029, both allowing for less time than the study’s stated minimum timeframe.

The lifespan of a thermal beneficiation plant is estimated to be 30 years.

No one seems to know how the deadlines in CAMA were determined. Duke Energy said to ask the legislators, but each legislator asked either didn’t respond or suggested that another legislator be asked.

“I can say that closure deadlines are one of the factors that we look at in determining where these units will ultimately be located,” said Chatman. “Sites with closure deadlines in the 2028-2029 time frame are better candidates for recycling since it allows you time to recycle a substantial amount of material, making the investment more cost competitive with other closure options.”

Duke Energy estimates it has 158 million tons of coal ash stored in impoundments and landfills at the company’s 14 North Carolina plants, with 124 million tons at its active plants. At the rate of 900,000 tons per year, it would take 138 years to beneficiate its current inventory at active plants (assuming no waste ash, and not counting gypsum, which is also recycled from coal ash).

Despite lower ash production as the company’s energy mix shifts more toward natural gas, the study predicts Duke Energy will continue to produce more than a million tons of ash annually for the foreseeable future.

Ash that is not beneficiated will be relegated to landfills or left in wet impoundments.

Ash quality matters
Southern bakers know that the wrong flour can ruin their biscuits. The same goes for concrete made with coal ash.

The market study states that thermal beneficiation processing “is a proven and highly flexible technology that can operate on a variety of ash types with a wide range of carbon concentration. It produces an ash that is low or even free of carbon. It also eliminates ammonia from fly ashes impacted by nitrous oxide controls. In addition, the process also produces ash with improved fineness by liberating the very small particles that are trapped in the carbon particles.”

Coal ash displaces Portland cement in the concrete mixture, and the ash makes for a more durable product. Further, the creation of Portland cement is also a major contributor to greenhouse gas emissions. For those reasons, coal ash is now required to be used for many construction and transportation projects.

“In order to make concrete to meet specifications,” Batten says, “we have to have it.”

UPDATE:
Following publication, we received additional information from Jennifer McGinnis, Attorney and Principal Legislative Analyst for the N.C. General Assembly, as requested by Rep. Pricey Harrison. In essence, McGinnis said that due to confidentiality agreements she couldn’t speak specifically to how the coal-ash cleanup deadlines were established in North Carolina law, but that based on public feedback that “I think there was a desire to close the ponds, and eliminate associated risks, as quickly as possible.” She also referenced the U.S. Environmental Protection’s coal-ash regulation, which became effective in Oct. 2015.

CORRECTION:
Henry Batten wishes to correct this quote: Batten reports that his company “consumes about 2.1 to 2.5 million tons of ash annually,” writing via email: “The quote was referring to cubic yards of concrete at 2.5 million cyds. We consume about 150,000 to 200,000 tons of ash annually.”



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Ethics case leaves unanswered questions over N.C. governor’s meeting with Duke Energy

This article was originally published by Southeast Energy News and is republished here with permission. The article was written by Coal Ash Chronicles’ director Rhiannon Fionn.

While the North Carolina Ethics Commission earlier this year dismissed a complaint against Gov. Pat McCrory’s office related to a meeting with Duke Energy officials and other issues, advocates say key questions remain unanswered.

In particular, the process did not provide any more insight into a 2015 dinner between state officials and Duke Energy’s CEO and key staff. Advocates have raised questions about the timing of the meeting, which took place just days before the state issued key permits for two coal ash sites.

“They just looked at it on its face and didn’t dig – they didn’t have time to,” says Therese Vick of the Blue Ridge Environmental Defense League, who authored the complaint.

In its decision, obtained by Southeast Energy News last month, the commission said there are not “facts sufficient” to determine a violation. Records requests by BREDL and media organizations have failed to turn up an agenda or notes from the meeting.

A government scholar says the commission acted within the scope of its duties.

“Based on my review of the complaint, Commission determination and state law, it appears to me that the Commission acted within the scope of its statutorily imposed parameters, a scope that it does not have the legal authority to exceed,” says Norma R. Houston, a lecturer for UNC Chapel Hill’s School of Government.

When asked to comment on the meeting, Duke Energy spokesperson Paige Sheehan responded via email, “As a highly regulated company, we seek to have constructive discussions with regulators and elected officials where we respond to their questions and update them on a variety of issues that are of importance to the state and its citizens.”

Gubernatorial debate revives controversy
At the time the meeting was disclosed by WRAL, a Raleigh TV station that discovered it through a review of public records, a McCrory spokesman said the discussion “included topics about the economy, the environment, energy and job creation.” State officials at the time declined to discuss further details.

During a debate between McCrory and political rival Roy Cooper, the state’s attorney general, on Oct. 18, the governor broke his silence about the meeting. McCrory, a longtime former employee of Duke Energy, stated that during the dinner meeting he and his guests discussed coal ash legislation that he later vetoed.

However, his statement does not match the timeline of events.

The North Carolina General Assembly passed the Coal Ash Management Act in 2014, which became law without McCrory’s signature in August of that year. The dinner meeting at the governor’s mansion took place 10 months later, and the vetoed bill in question wasn’t introduced in the General Assembly until a year after that.

McCrory did, in fact, veto a coal ash bill in July 2016, objecting to the creation of a Coal Ash Management Commission whose purpose would have been to watchdog the North Carolina Department of Environmental Quality during the statewide coal-ash cleanup process.

While the Cooper campaign did not respond to requests for comment, it did release a statement immediately following the debate pointing out the governor’s gaffe.

Southeast Energy News contacted the governor’s office for comment and was referred to his campaign chair, Ricky Diaz, who did not respond to multiple requests.

Coal-ash landfill permits issued following dinner meeting
The four-page ethics complaint, received by the Commission on June 26, 2016, cites potential violations of the State Government Ethics Act, including the June 1, 2015, dinner between McCrory, Duke Energy CEO Lynn Good, Department of Environmental Quality Secretary Donald van der Vaart, “and various legal counsel” at the governor’s mansion. The complaint also accuses the McCrory administration of using NCDEQ media resources for political purposes and cites a lack of transparency by state government regarding public records requests and the controversial dinner meeting.

In the complaint, Vick writes, “Four days after the meeting between the governor, Duke Energy and the DEQ secretary, permits were issued for two controversial coal ash landfills in Lee and Chatham counties.”

A press release announcing the issuance of those permits was published via NCDEQ’s website on June 5, 2015.

At that time, Vick says, “There had already been a violation at the Brickhaven location (in Chatham county); the violation was for doing something they didn’t have a permit for.”

Vick suspects the new permits were an outcome of the dinner meeting.

“I think that Gov. McCrory has a unique relationship with Duke Energy,” she said.

Requests for comment sent to NCDEQ Communication Director Mike Rusher went unanswered.

A March 2016 profile on NCDEQ Secretary van der Vaart in the Triangle Business Journal included this comment from him, “‘If you look at my publicly available calendar, you’ll find I have meetings with Duke all the time,’ he says, adding that he meets with all kinds of groups, from the state’s largest utility to the Sierra Club. ‘There’s nothing secret about that meeting. That’s a great example of a non-issue.’”

A matter of transparency
In its Notice of Dismissal, dated July 26, 2016, the Ethics Commission writes, “After reviewing the complaint and other information provided by Complainant, the Panel determined that the complaint did not allege facts sufficient to constitute a violation within the Commission’s jurisdiction.”

Vick, however, notes that the state agencies that may be in possession of those facts have been unwilling to make them public.

“Our compilation was pretty specific,” she says, referring to the portion of her complaint alleging NCDEQ’s failure to disclose information in response to public records requests.

In the complaint, Vick explains that she submitted a public records request to NCDEQ “asking for information related to DEQ staff meeting with representatives from Duke Energy. The information on the June 1 meeting was withheld. Also troublesome, the meeting was not disclosed during the discovery process related to challenges to two environmental permits regarding coal ash disposal.”

Information about the meeting was requested as part of the discovery process for a BREDL lawsuit regarding the mining permits and also as a separate public records request.

“We know that van der Vaart was there (at the dinner meeting), and he was one of the people that we had specifically asked for a list of any contacts he had with anyone from Duke Energy,” said Vick; “We found out about the dinner when the media found out.”

On July 21, 2015, at the request of BREDL, the North Carolina Attorney General’s office issued a memo to NCDEQ stating, in part, “As you should already be aware, your Departments are under a continuing obligation to preserve all records related to coal ash.” The memo continues: “This litigation gives rise to a legal duty to preserve records that may be potentially relevant to the case, and to prevent destruction of such records. The failure to adequately perform this duty, even when inadvertent or unintentional, can have serious consequences, including sanctions from the court.”

At the time it broke the news of the meeting, state officials told WRAL that no records of what was discussed at the dinner existed: “In response to a public records request, the Department of Environmental Quality said Secretary Donald van der Vaart neither received an agenda for the meeting nor recorded the discussion in any way. A similar request to the Governor’s Office yielded only emails and calendar entries arranging the meal and the meeting, but officials say there were no emails or other documents detailing what topics were discussed or why exactly the meeting was called.”

Ethics Commission findings confidential
“By statute, neither the commission nor its staff may comment on or provide any documents related to any complaint or possible complaint against someone covered by the Ethics Act,” wrote Pamela B. Cashwell, Assistant Director of the North Carolina State Ethics Commission. “Complaints and responses filed with the Commission and reports, other investigative documents and records of the Commission connected to an inquiry, are confidential and not matters of public record.”

The Commission’s dismissal letter was provided to Southeast Energy News on Sept. 22 by Vick with the approval of BREDL’s attorney.

The Notice of Dismissal states that McCrory “was notified of the allegations on June 27” and that the commission forwarded the complaint to McCrory on July 8 “and initiated a preliminary inquiry.” On July 20, “the Panel reviewed the information resulting from the preliminary inquiry.” And on July 26, the Notice of Dismissal was signed by Perry Y. Newson, Executive Director for the Panel.

The commission’s dismissal of her ethics complaint has not deterred Vick.

“If we don’t continue to push – the communities being impacted by coal ash and other things – to bring this information into the sunshine, they are going to keep doing their dirty work in the dark. They are certainly not trying to be transparent,” Vick says.



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Report outlines challenges to recycling North Carolina coal ash

Crews remove ash from the W.S. Lee Steam Station in Belton, S.C. Photo courtesy of Duke Energy.

Crews remove ash from the W.S. Lee Steam Station in Belton, S.C. Photo courtesy of Duke Energy.

This article was originally published by Southeast Energy News and is republished here with permission. The article was written by Jim Pierobon.

A long-awaited report presents a conundrum for coal ash recycling in North Carolina.

As Duke Energy, the state’s largest utility, works to meet state requirements to safely dispose of coal ash, there is a ready market for concrete producers, who currently import much of their fly ash from overseas. However, the technology to make North Carolina’s ash suitable for recycling may be too expensive to implement on a short timeline.

Technical and research executives at some concrete companies have expressed a willingness to shoulder all of the processing costs, including building facilities from scratch, but not without a guaranteed, long-term, supply of ash.

The report was coordinated by the Electric Power Research Institute (EPRI), which teamed with the University of Kentucky Center for Applied Energy Research and Golder Associates, an environmental consulting firm. It was submitted to the North Carolina Environmental Management Commission.

North Carolina’s Coal Ash Management Act lays out specific deadlines and options for closing Duke Energy’s ash basins. This year’s amendment to the act requires Duke to determine locations for two ash processing facilities by the end of this year and a third facility by next June. Together, Duke Energy is required to be able to process 900,000 tons of ash annually already stored in basins for the concrete industry once the facilities are built.

Last year, Duke Energy said it recycled 63 percent of the roughly 3 million tons of ash it produced – but did not dispose of – in 2015. How long it could take Duke to build the three processing facilities remains to be seen.

‘A significant investment’


Duke Energy spokeswoman Zenica Chatman said the company is using the report’s findings to help determine which plants that ash will come from and what new technologies can process more of it for concrete products.

Concrete makers say they could use a lot more ash now if it’s processed, or “beneficiated,” to meet quality control criteria. Many companies actually import ash from China and other countries because they say they can’t get enough of the right kind of ash in North Carolina. Ash that retains much of its carbon content that wasn’t burned due to emissions controls makes it less useful for concrete makers.

Most of the ash in North Carolina is stored in basins or ponds and concentrated at three of Duke Energy’s 17 active or retired coal-fired power plants. All totaled, ash is stored at 33 sites throughout the state. Currently there are a total of about 150 million tons of coal ash stored throughout North Carolina, according to Duke Energy.

Ash from the Marshall facility in Terell typifies the challenge and opportunity facing the utility and policymakers. While it generates a lot of ash and is in a “good” market location, the ash itself is only of marginal quality, thus requiring beneficiation, according to the report.

“Beneficiation represents a significant investment, with payback periods on the order of decades for some technologies,” the report said.

More recycling means less ash to be disposed of, further reducing risks to the environment and groundwater supplies, said Nick Torrey, an attorney with the Southern Environmental Law Center in Chapel Hill, North Carolina.

“The more people who learn about the absurdity of importing coal ash,” SELC’s Torrey said, “the sooner progress can be made. We should be making more out of the ash we already have.”

North Carolina vs. South Carolina


South Carolina has made significant progress on coal ash due in large part to legal action against utilities there and a more responsive government. That has contributed to the commercialization of two reprocessing facilities there developed by the SEFA Group.

“The one thing that stands out in South Carolina is the role of state government,” Torrey said. SELC sued Santee Cooper and South Carolina Electric and Gas, two large utilities there, to facilitate action there.

Cassie Gavin, a lobbyist for the Sierra Club in North Carolina, agreed. She said without incentives, Duke Energy will pursue the least-cost options. “Right now, there’s no financial incentive for them to do so.”
The EPRI report outlines new options for processing ash, but most of them are too costly without a guaranteed, long-term, supply of ash from Duke Energy. Industry experts and environmental advocates don’t expect Duke Energy to do anything more than what current law calls for.

“For concrete, fly ash is priced competitively with Portland cement and represents a potential revenue stream,” according to the market assessment portion, or Phase 1, of the report.

Phase 2 of the report explores commercial beneficiation technologies. Phase 3identifies technologies and the ash products they produce that currently have a limited market, or no market, in the U.S.

‘Concrete producers are willing to pay’


Companies such as the Concrete Supply Co. of Charlotte, where Duke Energy is headquartered, and Chandler Concrete Co. of Burlington, North Carolina, have spoken out or lobbied for a law requiring utilities to give up a lot more ash and more quickly than current law requires. That, they said, would help foster long-term supply contracts.

Jimmy Knowles, a vice president at the SEFA Group, said, “concrete producers are willing to pay for quality fly ash which, in effect, pays for the removal of ash from coal ash ponds.” This, he added, is preferable to “having ratepayers pay to clean up old ash ponds which are environmental liabilities.”

Complicating the decisions how and whether to treat coal ash is the longer it sits in ponds or landfills, the more it deteriorates, making it more costly to process it for construction projects. The utility industry’s transition away from coal also means less ash is being produced.

“As an industry, we need a high quality fly ash available year round,” said Eric Misenheimer, Technical Services Manager at Chandler Concrete Co.

SEFA’s Knowles explained that if “high-quality” ash were consistently and readily available in North Carolina, “concrete producers would use more of it and the coal ash stored in ponds would be eliminated more quickly.”

If fly ash “just barely meets the minimum requirements of ‘specification-grade fly ash,’ it will not translate into the intended outcome for North Carolina,” Knowles said.

Knowles explained that many of the ash treatment processes cited in the report have been tried before but without commercial success. “However, the opportunity/technology to reclaim coal ash from ponds and use it as SCM (supplementary cementitious material) in concrete is very realistic,” he said. “We are doing it every day in South Carolina.”

Policy challenges


Chatman said the scope and scale of ash for Duke Energy to manage in North Carolina very different than South Carolina’s. “We also have aggressive state deadlines we must meet for closing ash basins that do not apply in South Carolina.” Some of those deadlines fall before new processing facilities could likely be built.

The EPRI report states that “while some regulatory uncertainty remains, especially at the state and local levels, the regulatory environment should provide a growing forward market in environment that encourages innovation and development of new use technologies.” It goes on to spotlight other options: “Applicable technologies for the recovery and processing of wet ash can be readily found in the mineral processing industries.”

Henry Batten, President of Concrete Supply Co., said he wishes Duke Energy was more proactive about coal ash solutions. “As much as I want to browbeat them,” he said he understands that won’t happen unless the utility is required to act.

“Duke could lead the market in supplying reclaimed ash if they wanted to,” Batten said.


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For closing North Carolina’s coal ash ponds, one size doesn’t fit all

Catawba Riverkeeper Sam Perkins patrols the Riverbend Steam Station on Mountain Island Lake near Charlotte, North Carolina.

Catawba Riverkeeper Sam Perkins patrols the Riverbend Steam Station on Mountain Island Lake near Charlotte, North Carolina.


This article was originally published by Southeast Energy News and is republished here with permission. The article was written by Coal Ash Chronicles’ Rhiannon Fionn.

As North Carolina’s policies for coal ash cleanup continue to evolve, the discussion has centered largely around two options – total excavation of ash ponds, or “cap-in-place,” essentially draining and covering the ash where it sits.

And as Duke Energy pushes for the latter, less expensive option, advocates and experts say other techniques may pose fewer risks to the public.

In May, when the state Department of Environmental Quality called for all coal ash sites to be excavated in North Carolina, Duke Energy, the state’s largest utility, called it “the most extreme” option. A new law, passed in July, allows for the ash to stay put if the company establishes permanent drinking water solutions for affected residents by 2018 and repairs the earthen dams holding the impoundments in place.

“Cap in place,” or “closure in place,” is the practice of leaving an industrial waste impoundment in place and covering it with both earthen and synthetic materials, it’s a closure option that’s been in use for decades, and one the Tennessee Valley Authority intends to use at its coal ash sites fleet-wide.

In North Carolina, Duke Energy projects that in 2016 alone it will excavate 2.25 million tons of coal ash in North and South Carolina. Fleet-wide, the company stores a total of 180 million tons of coal ash in wet impoundments, according to spokesperson Paige Sheehan.

Problems with cap-in-place
While state officials insist cap-in-place is safe, environmental advocates argue it doesn’t prevent groundwater contamination or eliminate the risk of dam failures.

“There are a number of problems with the sites in North Carolina,” says Sam Perkins of the Catawba Riverkeeper Foundation. “First and foremost, they are unlined, and that is a major problem with capping them in place. In some cases, a vast majority of the ash lies below the groundwater table – that’s in the engineering reports. There is significant concern about continued leaching because of lateral groundwater movement,” he says.

“The dams sometimes continue into the lake,” he says, “These are waterways that serve as drinking water reservoirs that have flooding issues that we’re seeing becoming worse due to increased stormwater runoff. That is going to be a structural problem regardless of (excavation or capping in place) because they’re saturated with water.”

Other options
Christopher Hardin, an engineer and consultant who works for the University of North Carolina at Charlotte, says hybrid closure methods are the way to go, combining excavation, capping and stabilization methods while reusing the ash when possible, and that each site’s closure plans should be customized.

He’s a proponent of a process called “stabilization in place,” or solidifying coal ash in impoundments with concrete or lime, which, he says, is a closure procedure already in use at other waste sites; he’s looking for a test site to prove the method for coal ash impoundments.

Hardin harbors some concerns about excavating ash too close to dams and “potentially failing them.” Stabilization-in-place could be used to solidify ash near the earthen dams, he says, making it safer to excavate the interior of the impoundments. He also says that instead of dewatering the impoundments – a practice that recently spiked arsenic levels in Charlotte’s drinking water reservoir, the water could be mixed in with a stabilizer and ash.

According to Robert Bachus of Geosyntec Consultants, it’s the water on top of the impoundments that can lead to “flows” like the one that occurred during the 2008 Tennessee Valley Authority spill that clogged two rivers and covered more than 300 acres in black sludge.

Hardin agrees that removing the water – whether through dewatering or as part of a stabilization method – reduces the risk of a dam failure. However, he says it’s important to conduct an analysis at each site and that he’d like “the legislature to stop dictating the remedies, listen to the citizens and develop (closure) plans on a site-by-site basis.”

Dr. John Daniels agrees: “It’s not one size fits all,” he says. Daniels is an engineering professor at UNC Charlotte and chair of the National Coal Ash Advisory Committee. He has developed a laboratory method using organo-silane chemistryto make coal ash water-resistant.

“It could be used where you want to control infiltration – maybe that’s cap-in-place, maybe that’s a new landfill, maybe that’s beneficial reuse. Anytime you’ve got ash, and you want to prevent water from getting into it, this might be something you would want to consider.” He, too, is seeking a test site.

Another engineer seeking a test site is Tim Siler, a geoscientist and former environmental risk manager for Progress Energy, which merged with Duke Energy in 2012; he also consults for Duke Energy. Using his method, “the ash is hydraulically isolated from the groundwater by constructing a hydraulic barrier at the bottom of the impoundment using engineered in-situ solidification/stabilization application on the ash and/or underlying natural material.”

Siler says the process, which is already used at “a number of EPA Superfund sites,” enhances the stability of the dams while creating a barrier between the ash and groundwater. “This could be used at sites where it might not be feasible to excavate,” Siler says, adding, “there won’t be groundwater flowing through the cell and leaching and contaminating groundwater.” The process also preserves the ash for future beneficial reuse.

“It’s more expensive than cap-in-place,” Siler says, “It’s a fairly labor-intensive solution, but it certainly costs less than excavating.” He says he’s presented his method to Duke Energy, environmental advocates, and North Carolina regulators and legislators. “We’ve gotten a very positive response,” he says.

Can’t be based on cost
Duke Energy estimates that traditional cap-in-place is the least expensive closure method for its impoundments in North Carolina. However, the EPA, in its coal ash regulation that became effective in October 2015, states that closure plans can’t be “justified based on the costs or inconvenience.”

“In South Carolina,” says Perkins, “where they decided to move the ash, we have not seen rates rise, or companies go bankrupt, but we have seen the arsenic levels (in the groundwater) drop dramatically.”

Department of Environmental Quality spokesperson Mike Rusher has stated that “Closure methods are to be determined in impoundment-specific closure plans. Only if Duke Energy meets the requirements of the law and meets the satisfaction of the department can an impoundment classification be eligible under state law for cap closure, or they may require excavation.”

“A dedicated team is hard at work to identify options that are proven, safe and cost effective,” says Duke Energy spokesperson Paige Sheehan. “Given that this is a dynamic process, we are not in a position to discuss any specific approach or vendor we might be considering right now. Once our plans are finalized and agreements in place we’ll be in a much better position to discuss the approaches we are taking.”

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