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South Carolina Governor applauds Dominion Energy, project partners, for completing project ahead of schedule
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Project crew completes complex a multiyear project to remove tar-like material from the Congaree River in downtown Columbia, South Carolina.On time and under budget.
That’s the phrase any project manager loves to hear. And it came true in 2023 for Dominion Energy and its project partners on a complex, multiyear project to remove tar-like material from the Congaree River in downtown Columbia, South Carolina.
“This was a highly unique project that had never been attempted anywhere in the United States in a river at this scale,” Dominion Energy South Carolina President Keller Kissam said. “Its successful completion is a testament to the excellent coordination and relationships among our employees, regulators, contractors and stakeholders who helped guide the work. There were many who doubted that it could be done, but I’m proud to say that, not only did our exceptionally talented and dedicated team do it, they did it in a manner that sets the example for others to follow.”
Crews removed tar-like material in the Congaree riverbed that was first discovered in June 2010. Dominion Energy made a commitment to remediate the material after lab testing showed it was consistent with coal tar created at a manufactured gas plant located near what is now the South Carolina State Museum and operated by predecessor companies approximately a century ago. The plant produced gas from coal, oil and other feedstocks, which was used for lighting, cooking and heating Columbia homes and businesses.
Starting in June 2022, crews installed cofferdams and dewatering pumps at two locations in the river so they could work on a dry riverbed. They then removed more than 35,000 tons of sediment for disposal in an approved landfill. In addition to the sediment, crews also removed more than 2.5 tons of debris from the river, including tires, scrap metal and other trash.
– Keller Kissam - President, Dominion Energy South Carolina
The modified removal agreement reached with the South Carolina Department of Health and Environmental Control, Army Corps of Engineers and other stakeholders authorized work in the river from May 1 until Oct. 31 of each year.
“The river levels over the last two years were very cooperative,” Dominion Energy Director, Environmental Services Tom Effinger said. “It helped our crews finish work in the river a year earlier than originally scheduled. I’m very proud of the way our contractors found innovative ways to overcome the numerous challenges to make this happen for the good of our community.”
Elected officials, including South Carolina Gov. Henry McMaster and Columbia Mayor Daniel Rickenmann, joined other dignitaries in a November 2023 ceremony to recognize the $20 million project. "Protecting our environment and natural resources is a top priority for Team South Carolina," said McMaster. "Healthy waterways benefit us all and ultimately lead to a happier and healthier state. I thank Dominion Energy and all of those involved for getting this project done ahead of schedule."
Dominion Energy also worked with archaeologists to recover hundreds of historical artifacts from the river sediment, including cannonballs and other ordnance that have been in the river bottom since the Civil War. The artifacts were primarily weapons dumped into the river after Union troops captured Columbia in April 1865.
These two 10-inch artillery shells from the Civil War were recovered during the cleanup.
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