First stage of cofferdam on the Congaree River is complete

By Terry Ward

Work on the Area 1 cofferdam on the Congaree River, near the Gervais Street Bridge, is coming along.

The first stage of the cofferdam is complete. Dominion Energy is damming the river in order to clean tar from the bottom of the river.

In June an Unexploded Ordnance Diving Team from Tetra Tech arrived to clear Area 1 from any Civil War era munitions.

A second, smaller cofferdam will be constructed closer to the Blossom Street Bridge in Cayce.

The clean-up is being conducted on a portion of the river that could contain Confederate Army unexploded ordinances disposed of in February 1865, during The Civil War. It’s possible that unexploded ordinances are buried in the sediment.

Completion of the two dams is expected by October, said Greg Cassidy in May. He’s a project manager for the State Voluntary Clean-Up Program that is connected to the SC Department of Health and Environmental Control. Removal of the tar would likely begin in the spring of 2023 because of the unpredictable level of the river in the months of November, December or January, said Cassidy.