On Monday, the North Carolina Department of Environmental Quality issued determinations with respect to six Duke Energy coal plants, 
requiring that Duke close coal combustion residual surface impoundments at the plants by excavating and removing all coal ash from the impoundments. DEQ did so notwithstanding that the impoundments all received “low-risk” classifications by DEQ.
According to Greenwire (subscription required), the directives will increase the cost of complying with CCR requirements at these plants by $4B-$5B.
Why did DEQ require Duke Energy to remove all coal ash from on-site impoundments? Because it concluded that removing the coal ash “is more protective than leaving the material in place.”
Count me skeptical of DEQ’s conclusion. First, do landfills qualified to take CCR in these volumes even exist? We’re talking about a very substantial volume of waste. Second, what about years of truck traffic to remove all the CCR and the environmental costs and nuisance impacts of that work?
The DEQ directives were based on state law provisions, so for now coal plant operators outside North Carolina have nothing to fear. However, what happens if other states get the idea that replicating the North Carolina statutory requirements would be a good idea? Then we might really find out how much capacity is required to move and redispose of all of the CCR currently in surface impoundments at coal plants in the United States.
I hear Yucca Mountain has some extra capacity. I’m sure Nevada would love to have the nation’s CCR!
I think your skepticism is well founded, but this is a complicated situation. I was in charge of part of the EPA’s 18-month field monitoring study of coal ash disposal at one of these plants (Allen Steam Station near Belmont) in the 1980’s. At that time, we found that potentially toxic metals in groundwater, including arsenic, were being attenuated in and under the un-lined ash pond by other substances (e.g., iron), so that they didn’t reach the nearby Catawba River. Is that still true today, or has the attenuative capacity been exhausted? I don’t know…
However, it seems to me that case-by-case field measurements, if not already done, would be appropriate instead of a one-size fits all regulation.