Dive Brief:

As Hurricane Florence takes aim at the southeastern United States, utilities in the region say they are prepared to deploy emergency protocols.

Power outages associated with the Category 4 storm could last for days or weeks in the Carolinas, Duke Energy officials told Utility Dive. Flooding could also affect regional power plants, like in 2016, when Hurricane Matthew flooded cooling ponds at Duke Energy's Lee coal plant.

Another concern is the fate of unlined coal ash pits in the Carolinas and Virginia. Duke and Dominion Energy still have several unlined coal ash facilities along the coast and inland that leave communities vulnerable to potential flooding or leaks from the sites, Frank Holleman, a senior attorney at the Southern Environmental Law Center, told Utility Dive.

Dive Insight:

U.S. utilities are bracing themselves for another round of powerful storms after a record season in 2017.

Last year, Hurricane Harvey cost utilities in the Gulf Coast region around $520 million in damage, and weather events as a whole cost U.S. utilities $306 billion, the highest figure ever recorded by the federal government.

Experts say the more powerful and frequent storms are fueled in part by a warming climate. Repairs to Puerto Rico's electric grid in the wake of Hurricane Maria are expected to take years, and Hurricane Isaac is expected to slide just south of the island this week.

Further west, Hawaiian Electric is monitoring closely Hurricane Olivia, which could hit the state this week as well.

The biggest storm, however, remains Hurricane Florence, and utilities along the southeast coast have spent the week outlining safety measures customers should take, including staying clear of fallen power lines and evacuating if necessary.

"Everyone at [Duke] has a storm job," said Paige Sheehan, director of policy and environmental communications at Duke Energy. Thousands of the utility's employees being deployed across affected regions, she said.

"We're particularly focused on senior citizens or people with medical conditions, making sure that they're in a safe place so emergency personnel can get to them if there's a real crisis," she said.

A particular concern for many residents in the southeast is the safety of the region's coal ash pits, which store the toxic byproduct of burning coal for electricity generation.

While South Carolina coastal utilities, such as SCE&G and Santee Cooper have been working to excavate coal ash facilities, Holleman said inland and coastal facilities at Duke and Dominion are still at risk.

At Duke, coal facility preparations are "much the same" as preparing the rest of the company's assets for the storm, Sheehan said.

"Several days ago we started taking steps to make sure coal ash basins and all the different infrastructure around them are prepared for Florence," she said. Coal ash basins that are in the closure process have significantly less water, she added, which creates space that could prevent overflow in the case of flooding.

The utility is considering deploying drones for aerial surveillance if it's unable to access coal ash ponds on the ground. Part of its inspection rules require observing inactive ash basins after 4 inches or more of rain in a 24 hour period.

Duke's main concern is not with coal ash, Sheehan said, but with plant cooling ponds.

In 2016, rains from Hurricane Matthew flooded those ponds at the Lee plant in North Carolina, a converted coal generator that now runs on natural gas.

Photos released by an environmental group following the storm led activists to demand answers from the utility about how much coal ash from the plant was released to the surrounding area. Duke maintained, however, the photos showed an inert byproduct of coal generation called cenospheres, not coal ash.

Either way, Holleman said Duke and other utilities should have moved their facilities away from waterways and toward dry storage years ago, so there would be less risk to communities.

"There is one and only one way that the coal ash utilities can protect communities from the threats posed by hurricanes like Florence, floods, and intense local weather events," he said.

To do that, utilities must "remove their coal ash from primitive unlined leaking riverfront lagoons and move it to safe dry lined storage away from the waterway or recycle it for cement and concrete."

The current practice of keeping coal ash so close to waterfronts "is irresponsible and dangerous," Holleman added.

Duke and other utilities say they are moving to close the riskiest coal ash facilities after a series of ash spills sparked new regulatory requirements.

In 2014, the EPA reported 39,000 tons of ash and 27 million gallons of ash pond water flooded from the utility's Dan River Stream station to the surrounding area. Following the spill, the utility pled guilty to nine Clean Water Act violations relating to its handling of coal ash in North Carolina, forcing it to commit to dry, lined storage facilities and close other basins, in line with the Obama administration's Coal Combustion Rule.

Duke joins a number of other power companies shifting towards dry storage, including Georgia Power and Tennessee Valley Authority, after a slew of concerning spills over the past decade.

"Change is coming," for the management of coal ash pits, Holleman said, but for now communities can only "cross their fingers."