COLUMBIA, S.C. — Driving down Columbia's Gervais Street looks a little different now if you look over the bridge.
You'll find a giant coffer dam being built by contract workers. The project is a combined effort from the Congaree Riverkeeper, DHEC and Dominion Energy.
Wheels are turning, trucks are dumping rocks and workers are operating heavy equipment to make sure it all stays compacted.
Progress is moving along in the Congaree river sediment cleanup.
"They're working from both ends. They're almost ready to connect in the next couple weeks, then they'll build the dam up a little more, then put these concrete mats on top and then that will allow them to go in and dewater that area, start digging and then treating what they've got and hauling it out to the landfill," Bill Stangler, Congaree Riverkeeper said.
Stangler explains a few thousand tons of chemically-infused coal tar is sitting underneath this water and sand from centuries ago.
The tar drained into the river from an old gas plant in the area that closed back in the 1950s.
Dominion Energy purchased the Cayce-based company SCANA three years ago, which makes them responsible for the project.
"When Sherman took Columbia and the union soldiers burned down the city, they took the confederate armory, marched it out to the end of Senate Street and dumped it in the Congaree river here, so there's potentially a lot of historic artifacts underneath that coal tar, but also potentially unexploded cannon balls," Stangler said.
Today, in June 2022, agencies are now cleaning up after them.
"We would get calls, year after year of people taking out of the river from kayaking or tubing and getting this tar on them. They couldn't get it off and it burned their skin," Stangler said.
The dam should be done by the end of July if weather allows, then throughout the next 3 -5 years they'll section off other areas of the river where tar sits.
According to Dominion Energy, crews will work on this project May to October each year.
The access point to the river at Senate Street will be closed the next several years, so you will have to go to the West Columbia Riverwalk, Grandby park or downstream boat ramps instead.