Lynn Good: Lesley, we're committing to closing all of the sites.
Lesley Stahl: When you say "close," what do you mean by "close?"
Lynn Good: So there are various methods that can be used to close. Certainly excavating them to a lined landfill is one of the methods.
That method would cost up to $8 billion. But Duke is considering two other options: lining the bottom and top of the ponds but leaving the ash there which would cost somewhat less, or least pricy at 2 billion: "cap in place" which means just covering the top of the pond.
Lesley Stahl: With no lining on the bottom?
Lynn Good: And typically "cap in place" is not lined on the bottom. But we would not move forward with a cap in place unless we had a certainty that the water is safe. And so that's where the science comes in. That's where the study needs to be completed, so that we develop smart solutions.
Lesley Stahl: It's called cap in place?
Frank Holleman: Cap in place.
Lesley Stahl: Obviously, I'm not a scientist, but shouldn't you just say, "OK, we're gonna line them all?"
Lynn Good: I'd love to tell you there is a simple solution to this. I'd love to tell you that ash--
Lesley Stahl: Well, why isn't that a simple solution?
Lynn Good:--that ash has been stored for decades can be solved quickly. We like quick answers. We like to pull our cell phone up and do research and get answers right away. But in order to do this right, we do need to do the study. We need to understand: What is the groundwater? Where is the groundwater? We need to understand the stability of the basin. We need to understand the soil type. I cannot immediately move 100 million tons of ash. It's not a response that makes any sense, doesn't make common sense. As much as I'd love to tell you there's a simple solution, it's one that requires study, it's one that requires time to complete.
But environmentalists say studying is code for stalling, because this problem isn't new. Duke has been conducting tests around their ash ponds for decades. And five years ago, when state regulators demanded to see the data, they found something alarming: the coal ash ponds in all of Duke's 14 plants were either leaking toxic chemicals into rivers and streams or contaminating the groundwater.
Lynn Good: Some of the readings that we have found are for elements like iron and manganese, which are naturally occurring.
Lesley Stahl: But nine of your plants have been found to have groundwater violations for contaminants including lead, sulfate, boron, chromium, thallium, selenium, and arsenic.
Lynn Good: So we have had exceedances. And when I said iron and manganese, Lesley, I was talking about the majority of them. We have had instances of other readings as well.
Lesley Stahl: Well, I'm citing your own monitoring statistics, which do say that there have been hazardous chemicals that have entered the groundwater or surface water, at all 14 plants, by your own admission.
Lynn Good: And what we have recommended, and will be moving forward with, and the state has recommended, is further assessments so that appropriate steps can be taken. (Lesley laughs) So, Lesley-- I think--
Lesley Stahl: Further assessments!
Lynn Good: I know, I think it's important to understand this. And I--
Lesley Stahl: But even you have to throw your head back and say, "Further assessments?" Yeah, but-- but these results go back years. And to say we need to study more, you know, is a very frustrating thing to have to hear. And I'm not even a citizen of North Carolina.
Lynn Good: We have very openly and transparently disclosed these results to work with the regulators to determine whether it really represents a risk.
Lesley Stahl: Does Duke's coal ash today pose any health risk at all?
Lynn Good: I believe our system is operating safely.
But local environmentalists showed us leaks from several of Duke's ash ponds - like this one at Cape Fear.
Kemp: This stream is like this, leaking coal ash into the river 24 hours a day, 365 days a year.
After we asked state officials about this particular leak, lab tests were done showing "notably elevated concentrations of sulphate, aluminum, iron, manganese, boron and strontium." The state says the leak doesn't impact the overall health of the river, but is illegal; a violation of the Clean Water Act. Yet environmentalists like Frank Holleman say that over the years the state never forced Duke to clean up its ash ponds, under both Democratic and Republican administrations.
Lesley Stahl: How powerful is Duke Energy in the state of North Carolina?
Frank Holleman: It's the most powerful entity in North Carolina. It spends millions of dollars on political contributions and it has traditionally had a very close relationship with the state regulators.
Just last year, Gov. McCrory cut the budget and staff of the specific department that inspects the ash ponds. The state legislature did pass a law in August, requiring Duke to clean up its plants, but only after the company had already volunteered to do that. Earlier, when Holleman tried to sue Duke, he was thwarted by the state which stepped in and negotiated a settlement that allowed Duke -- you guessed it -- more time to study, and imposed only a paltry fine.
Lesley Stahl: Tell everybody how much the fine was.
Pat McCrory: I don't have that list, but again--
Lesley Stahl: It was $99,111--
Pat McCrory: That's correct.
Lesley Stahl: which does not sound like a big fine.
Pat McCrory: It wasn't a big fine.