The answer, as the Greensboro News & Record reports, is “it depends.” A sample quote:

If coal ash were a person, it would need a really good psychiatrist to treat a classic case of schizophrenia.

Is this power-plant byproduct the “toxic sludge” so threatening to the state’s ground water, streams and lakes?

Or is it the potentially beneficial substance Charlotte coal ash expert John Daniels works with in a quest to recycle more of it in roads, buildings and other uses?

“It’s important to remember that 99 percent of this material is just like soil,” said Daniels, an associate professor of civil engineering at UNC-Charlotte. “It’s that 1 percent that gives it the bad name, but really you can have regular dirt that is just as bad.”

and:

The stuff is, indeed, potentially harmful in the massive quantities it has been stored up by Duke Energy and other power companies around the nation.

“The difference between a poison and a remedy is the dose,” said Daniels, who is among a team of coal ash researchers at UNC-Charlotte. “Let’s keep the actual risk in perspective.”

You can read the rest of the story here.