RALIEGH, N.C. -- This week, Duke Energy presented an update outlining possible costs of cleaning up coal ash in North Carolina.
Depending on what method the company is required to follow, it predicts the solution could cost between two and ten billion dollars.
According to Duke Energy Spokesperson Tom Williams, Duke Energy presented options but is not necessarily recommending a particular one.
"We just said we think the answer may lie somewhere within this spectrum," said Williams.
He referred to charts presented to the NC General Assembly's Environmental Review Commission.
The presentation and transcripts are located on Duke Energy's ash management webpage.
Duke Energy already has plans to move or convert ash at four plants, including the retired Dan River site.
The wide range of cost variations mostly come from questions about what to do with the remaining ten plants.
"All these sites are different. Some sites are small, some are large, some have more ash than others, some already have lined landfills in them we've been depositing ash in for some time," explained Williams.
The "one-size-fits-all" option would be most expensive, said Paul Newton, North Carolina State President for Duke Energy. It would involve totaling excavating and removing coal ash from all sites. Duke Energy estimated a seven to ten billion dollar price tag for that type of project.
Williams said the amount does not account for all variables, including inflation. "It's also the high range there. There is a much lower number that calls for more site specific activities," he said, referring to the less-expensive option.
That is called a "hybrid cap in place," where water would be removed from ponds and the ash would be covered so it stays dry.
Ponds that are not lined would still have the risk of groundwater contamination. Duke Energy said it would continue its monitoring of groundwater at those sites.
FOX8 shared a story last month about a South Carolina energy company, Santee Cooper Power, moving 11 million tons of coal ash over 10-15 years. Its estimated cost was $250 million.
Duke Energy is managing about 100 million tons of coal ash at fourteen sites. It said depending on the method, coal ash cleanup could take twenty to thirty years.
The effect on ratepayers would depend on which method the legislature mandated and how the utility commission reacted.
"To determine the cost in customers’ bills- that's really something, unless the law changes in some fashion, that's something the utilities commission will have to administer based on what the policy decision is," added Williams.