Duke Energy refused to share possible effects of coal ash dam breaches

Officials from the Department of Environment and Natural Resources say Duke has failed to provide maps that detail how breaches in 29 of the state's 46 high-hazard coal ash dams would affect surrounding areas. Known as inundation maps, these documents form a crucial part of emergency action plans in the event a dam fails.

North Carolina is one of 10 states in the country that does not require dam owners to file these emergency action plans, according to DENR spokeswoman Bridget Munger. But since DENR officials took over regulation of all of the state's dams in 2010, it has required EAPs every time a dam operator applies for any kind of new permit.

"That gives us some leverage to work with," Munger said.

But documents show the same law granting the agency that regulatory authority created a loophole Duke has used to get around the inundation map requirement.

One of bill's authors says that's not how it was supposed to work.

"That's a troubling matter, and I guess we could fix that in the coal ash legislation we're going to be filing in the next few weeks," said state Rep. Pricey Harrison, D-Guilford.

Search NC's coal ash records

Prior to 2010, Munger said, the safety of the dams keeping coal ash in retention ponds was essentially self-regulated. Duke inspected these facilities every five years, then reported its findings to the state Utilities Commission.

“Because of potential risk posed by the location of North Carolina’s coal ash ponds, we must provide greater oversight and more frequent inspections,” Perdue said in a release at the time. “This legislation will keep our citizens safer and our dams more secure.”

For a while, Munger said, the measure mostly worked as intended.  

"When that was passed and the program was new here, there was a process over the first year of starting to work with these companies," she said.

Progress Energy, which owned about 20 of the high-hazard dams, supplied many of the required inundation maps. Duke, she said, was less amenable.

"Staff was indeed frustrated because that last part kind of tied the hands of the regulators," she said.

While the state has some form of EAP on file for 38 of the 46 high-hazard dams, state data show inundation maps are old or missing entirely from two-thirds of the structures.

"An EAP without a valid and up-to-date inundation map is pretty much no good," Munger said.

Duke, DENR kept potential impacts of coal ash dam breaches secret

Although it was a busted drain pipe and not a breached dam that caused the coal ash spill in early February that released 40,000 tons of coal ash into the Dan River, Duke is shifting its stance on the release of these impact maps.

"It will take several months to update the plans because we intend to incorporate our learnings from Dan River, and this process is underway," Duke spokesman Thomas Williams said in an emailed statement.

Williams said in the email that Duke's practice is to keep emergency plans related to "major critical energy infrastructure" confidential for security reasons. But reached by phone Wednesday afternoon, he offered no explanation for why this information wouldn't be shared with environmental regulators or emergency responders.

Harrison said Wednesday that she wasn't aware energy companies were using the measure she helped craft to get around emergency plan requirements. She said the provision was inserted into the original bill to give coal plant operators planning to convert to cleaner energy some leeway with the Clean Smokestacks Act.

But as legislators enter the short session in May, she said making a fix to the oversight law is "kind of a no-brainer."

"It's been an important tool," Harrison said, "so I think we have to tighten it up."