Publisher's note: The author of this post is Dan Way, who is an associate editor for the Carolina Journal, John Hood Publisher.
Engineers: Reprocessing waste makes roads, bridges more durable
Raleigh — Duke Energy officials unsuccessfully urged state lawmakers to reconsider mandatory deadlines for cleaning up coal ash ponds around the state, and an environmental researcher agrees that arbitrary timelines could affect the utility's ability to recycle safely leftover materials stored in 33 ash basins around the state.
Senate Bill 729
, sponsored by Senate leader Phil Berger, R-Rockingham, and Sen. Tom Apodaca, R-Henderson, survived a host of committee votes last week and is on Tuesday's calendar for consideration by the full Senate.
"Ultimately, you want all of these ash ponds cleaned up, but you want to do it in a responsible way that maximizes the recycling potential of the material," said John Daniels, associate professor and interim chairman of civil and environmental engineering at UNC Charlotte.
Daniels cautioned against relying on storing the coal ash — residue remaining after burning coal to create electricity — in landfills, and instead urged maximizing its use as a construction material.
Quick timelines should be set to do a risk assessment and develop plans, Daniels said.
"But as far as actual implementation, and to say, 'Thou shalt remove all ash by a certain date,' we want to be careful with that because there are unintended consequences that can occur," and "dubious benefits," derived, Daniels said.
"I'm very sympathetic to those who are concerned with ash" because of past spills that have compromised water quality, Daniels said. But he believes a degree of alarmism over the Dan River coal ash spill is driving public policy.
"It's constantly characterized as toxic coal ash, and I think it's irresponsible to characterize it like that," Daniels said. "It's not hazardous waste, and it's not inherently toxic." The toxicity of the ash depends on the volume of the chemicals in the ash.
"If the litmus test is that ash leaches contaminants at levels above groundwater standards ... then the entire country is hazardous," he said, from compounds seeping naturally from soil. "That's not to diminish the need to manage this stuff properly" through regulations.
Daniels agreed with Damian Shea, professor of environmental toxicology at N.C. State University, who told members of the capital press corps at a recent luncheon that no short-term toxic harm has been found from some 39,000 tons of coal ash that leaked from a stormwater pipe at a closed Duke facility into the Dan River.
Shea said he knows of only "very isolated cases" in which coal ash spills contaminated groundwater. But long-term monitoring must be conducted along the Dan River where the coal ash settled, and the state needs to determine how to best deal with its coal ash ponds.
Recycling for construction
"One of the things that the coal ash recycling industry is spending a lot of time thinking about, talking about now, is whether there's an opportunity to go into some of these older ponds and landfills and apply some technology, and use them as a source of supply for future ash," said John Ward, a committee chairman for the American Coal Ash Association and representative of Citizens for Recycling First.
"That's a future frontier for this industry. There's not a lot of that going on," Ward said. Technology now exists to transform the old, wet material stored in ash ponds into a finer, dry fly ash material commonly used in making concrete. The fly ash makes concrete less porous than Portland cement, bond more tightly, and flow more smoothly.
A little more than 40 percent
of dry coal ash produced today is recycled and repurposed for concrete, wallboard, mining, structural fill, embankments, and agricultural purposes, among other uses.
Santee Cooper, South Carolina's largest energy utility serving 2 million customers, has contracted with the SEFA Group
to reclaim and reuse stored coal ash at two sites. South Carolina-based SEFA already is converting wet coal ash to higher-use dry ash at one Santee Cooper plant, and is building a second facility.
"We have contracts to beneficially use or recycle ash in all seven of our ash ponds at three different generating stations. We expect that this will take us 10 to15 years," said Mollie Gore, Santee Cooper spokeswoman.
"In the case of our customers, it is the lower-cost solution to the long-term question of what are we going to do with our ash ponds," Gore said. "Transporting to a landfill was significantly more expensive than encapsulating in place," and "we stopped counting" the cost savings by using SEFA technology instead of those options.
"The cost we've put on this for the entire program is $250 million. That includes cleaning out the ponds, and it's delivering the ash to the customers," Gore said.
Duke spokesman Jeff Brooks said the nation's largest utility is looking into the "carbon burnout process" technology to refine wet coal ash into dry form for use by the concrete industry.
"You'd have to build a new facility, and I think we've heard early estimates of around $30 million," Brooks said. "I think that when you look at that, those facilities would be built on site, or near the site, and the coal ash would be converted there."
Ward said the American Road and Transportation Builders Association conducted a study a few years ago that found using ash to increase the durability of concrete "saves us over $5.2 billion a year by making concrete roads and bridges last longer."
Using coal ash reduces the amount of water and energy required to create concrete, and landfill space to store it.
"In a lot of places in the country, the state departments of transportation require the use of it in order to improve the concrete," he said.
"We do actually require its use in certain projects, particularly bridge decks where there would be a lot of salt, like at the coast, and our divisions essentially from Raleigh west, where we have the salt in the winter time," said Nicole Meister, spokeswoman at the North Carolina Department of Transportation.
Because ash is finer than cement, it fills holes better and protects against salt infiltration and corrosion, Meister said.
"The Federal Highway Administration encourages its use," Meister said. "Last year we used about 20,000 tons in our construction projects."
'Very aggressive' schedule
George Everett, Duke's director of environmental and legislative affairs, told Senate Agriculture Committee members Duke might be challenged to comply with the "very aggressive" cleanup schedule for removal of 102.2 million tons of stockpiled coal ash.
The proposed legislation requires closure of high-risk impoundments by Dec. 31, 2019, intermediate-risk facilities by Dec. 31, 2024, and low-risk impoundments by Dec. 31, 2029.
Everett said to meet the timetable to close high-risk ponds, Duke must compile a priority plan for the state Department of Environment and Natural Resources. DENR would study it and make a recommendation to a nine-member Coal Ash Management Commission that has yet to be created. The commission would approve a final priority list.
The priority list would then go out for public comment and hearings on a site-by-site basis. After gaining approval for the list, Duke would have to submit individual closure plans for each site and complete a second public comment/hearing process. Once closure plans are approved, the process of permitting, building landfill, and moving materials could proceed.
Everett said that process is "a little out of order" and asked for the timelines to be revisited, noting that if the necessary approvals took four years, Duke would have just one year to rush cleanup of four high-priority sites.
"I have found in my life I get more done when I have a tight guideline," Apodaca said, rejecting reconsideration of the timelines. "I think these guidelines could be met."