RUTHERFORD COUNTY N.C. -- Department of Environment and Natural Resources responded Duke's Energy's Cliffside Steam Station in Rutherford County after it was notified about a discharge.
On Thursday during a routine inspection, Duke Energy officials informed DENR they they discovered the discharge of approximately 0.8 gallons per minute coming from the permitted outfall of an emergency pond. Discharge from the pond is expected only during extreme storm events.
Officials found a corrugated steel outfall pipe was perforated from corrosion. This allowed groundwater to infiltrate the pipe.
Water infiltrating the pipe was reportedly discharged to the ground at a riprap area and never reached the Broad River, it's the closest body of water to the plant.
"Fortunately, we observe no environmental impacts from this discharge," said Tom Reeder, director of the N.C. Division of Water Resources. "However, we need to emphasize increased attention to all aspects of the infrastructure at Duke Energy's facilities across the state."
Attempts to repair the pipe Thursday were unsuccessful. Friday, Duke Energy employees started containing and collecting the discharging water into collection tanks. The company plans to pump and haul the collected from the collection tanks to a treatment pond on site twice a day until a permanent remedy is implemented.
Duke Energy collected flow data and took samples of the discharge water Thursday and tested it for total suspended solids, oil, great and pH.
The basin where the pipe is located is designed to hold comingled stormwater and wastewater overflow from an adjacent basin during extreme storm events. The last time the basin was used for emergency storage was in 2005 when a heavy storm brought 9 inches of rain to the area.
In this case, corroded areas of the pipe allowed groundwater to enter and move up through the pipe to the discharge point, where water was discharged and infiltrated the soil.
Representatives from DENR's Dam Safety Program plan to be on site early next week for a scheduled dam safety inspection and will also have an opportunity to examine the structure.