Carolina Utilities Assess Florence Infrastructure Damage
Story was updated on Sept. 21, 1:00 PM EST
As flooding spread in the Carolinas one week after Hurricane Florence made landfall in eastern North Carolina, utility crews still pushed to restore power and maintain clean water supply.
Duke Energy said on Sept. 20 that about 49,000 power customers remained without power in the Carolinas, down from about 450,000 in North Carolina alone on Sept. 17, primarily in the hardest hit areas along the coast. It expects full power restoration by late on Sept. 26.
“We do have quite a bit of infrastructure damage resulting in outages. Transmission lines, substations, poles,” says Candice Knezevic, a Duke Energy spokeswoman. “Catastrophic flooding and extensive damage have prevented crews from getting to the hardest-hit areas.”
Most state outages were Duke customers, but about 150,000 ere customers of smaller cooperatives that get their power from Duke. A damaged transmission line that serves at least one of the cooperatives is preventing power from being restored for those customers.
Duke is moving additional crews to eastern North Carolina to repair major transmission lines, Knezevic says. She says there are 20,000 lineworkers working in the state and that Duke has restored more power to more than 1.2 million customers. Just about 9,000 outages are being reported in South Carolina.
Water-Wastewater Service Challenged
Florence’s landfall in its large service area proved daunting for the Wilmington-based Cape Fear Public Utility Authority (CFPUA), which has at least 67,000 water customer accounts and more than 65,000 customers for wastewater treatment, with the utility noting about 200,000 people served and 1,000 miles each of water distribution mains and sewer mains.
CFPUA warned customers early on Sept. 16 of fuel shortages that were about to shut down water service but by mid-day it had secured sufficient alternative supply.
In a Sept. 20 report on its website, CFPUA said its drinking water plants and groundwater well system had remained fully operational during Florence with its Sweeney and Richardson plants and Monterey Heights well system producing and distributing more than 75 million gallons of safe drinking water during the storm.
However, Columbia, SC-based contractor M.B. Kahn Construction Co. Inc. told ENR that continued flooding of the Cape Fear River has prevented teams from damage assessment access to the site of its $1.4-million reverse osmosis treatment facility under construction at the Sweeney plant in Wilmington, possibly until about Sept 24, according to Bill Edmonds, executive vice president of its waterworks division. The project is set for completion next March.
The firm also said flooding in Fayetteville was hampering assessment of two other projects there but that 6 projects on the coast in Georgetown, Charleston, Beaufort, SC and Savannah, Ga. were not affected significantly.
Issues were more problematic on the wastewater side, with CFPUA noting impacts to facilities located at lower elevations.
Said CFPUA on it website Sept 20: "As expected, CFPUA’s wastewater system bore the brunt of the storm. We lost power to most of our 148 pump stations at some point during the storm, requiring emergency generators. Commercial power has been restored to many stations, but many remain on a generator."
With the power losses, backup equipment failure and flooding, the utility confirmed “we experienced 21 sewer releases, including one at our Southside Wastewater Treatment Plant," where 5.25 million gallons of partially treated wastewater were released into the Cape Fear River.
CFPUA said "releases of this size are not uncommon during extreme storms, adding that "the increased environmental impact ... is expected to be minimal because of the excessive rainfall and flooding conditions. Nonetheless, we will learn from this event and make our systems even more robust and reliable."
But the Associated Press reported on Sept. 20 that rising water at the Northwest Regional Water Reclamation Facility in Richlands "devastated" the plant, according to utility CEO Jeff Hudson, damaging electrical equipment for operations. He says partially-treated wastewater then mixed with floodwater but there was no contamination from hazardous chemicals at the plant.
Hudson was unclear how long repairs will take and the status of funds for new resilience measures.
But flooding has caused 21 hog waste impoundments to overflow in North Carolina, creating a contamination risk to standing water, said the state Dept. of Environmental Quality. It said four waste lagoons had structural damage and 55 were full or nearly full.
Coal-ash Sites Monitored
Also at risk are coal ash ponds at power plant sites. Duke is already repairing damage to oneat the Sutton Power Plant, near Wilmington that displaced about 2,000 cu yd of coal ash.
According to Duke spokeswoman Dawn Santoianni, Duke has identified a berm erosion as the reason for the release of coal ash and water at the plant. A second area of coal ash, about 25 ft by 100 ft, washed off the plant property and onto a nearby industrial site.
There were other areas of erosion at the site, but Duke says it believes most ash remained within its property. Inspections have not shown that any of the ash flowed into the Cape Fear River or nearby Sutton lake, Santoianni says.
Utility Santee Cooper is watching how close the still rising Waccamaw River in South Carolina gets to what the Charlotte Observer said was 200,000 tons of coal ash at a former power plant site in Conway.
Separately, an “unusual event” was declared at Duke Energy’s Brunswick nuclear plant in Wilmington because the roads to and from the plant are flooded, says Joey Ledford, a spokesman for the US Nuclear Regulatory Commission. The plant itself is not flooded and water is not near the plant, he says.
The plant was shut down in advance of the storm, a standard procedure for nuclear plants before a major storm. Because of the flooding, employees could not get in or out of the plant for a while. But Knezevic says the workers at the plant are not stranded and now can get in and out of the site.
Ledford said to his knowledge, this is the first time the site has flooded.
“Most of the roads around Wilmington are impassable,” he says. “It’s impossible to get around in personal vehicles."