COLUMBIA, SC (WIS) – Test results indicate the tarry substance recently discovered on the Congaree River bed in the area of Gist and Senate streets in Columbia is coal tar, a by-product in the operation of coal gasification plants, the state Department of Health and Environmental Control reported Wednesday.
The river is Austin Bunn's office. He runs kayak tours and knows the river like the back of his hand, but he recently noticed something strange. "About a month or two ago, I went out to do a little paddling," Bunn said. "I stuck my paddle in the ground, there was this black sludge stuff."
DHEC found the tar on the riverbed at about waist height after hearing complaints from swimmers. "It's a very sticky thing, leaving a black residue and smells like tar, a typical petroleum smell," described DHEC spokesman Adam Myrick. "Black, sludgy kinda, like black mayo."
At least two manufactured gas plants operated in the vicinity during the early 1900s, including one that belonged to a corporate predecessor to South Carolina Electric & Gas Company. "Although manufactured gas production in Columbia occurred between 55 and 100 years ago, we've just learned about this situation," said SCE&G President Kevin Marsh.
DHEC says all current evidence indicates the coal tar in the Congaree is from historical releases before downtown Columbia's last gas facility closed in the 1950s. Historic coal gasification operations have been identified beneath the former Columbia Supply Company at Lincoln and Lady Streets and beneath the former SCE&G bus maintenance facility on Huger Street. "They'd find the nearest body of water and they'd dump it or let it flow into it and that's what happened here," said Myrick.
DHEC thinks the tar rose to surface 100 years later because of sifting in the river beds. The agency says there is no evidence that a recent or ongoing release has occurred or that the ongoing cleanup of the Huger Street Site by SCE&G has contributed to the material discovered in the Congaree.
While it is not possible to determine the contribution from either of these facilities specifically, SCE&G has agreed to investigate and develop a cleanup plan for the sediments in the river. "It's simply the right thing to do," said Marsh. "If it's determined later that other companies have some responsibility in this matter, we'll address that then. What's important now is to focus our efforts on a remedy for the situation at hand."
"It's important to move as quickly as we can to address the issue, but we also want to make sure that we do things the right way," Marsh continued. "We want to make sure that natural resources are protected and that the folks who may be affected by the work or who may just be concerned about this – local residents, area businesses, recreational river users, and others – know and understand what we're doing every step of the way."
Marsh said the presence of the tarry substance in the river bed was first brought to SCE&G's attention in late June, when DHEC approached the company to determine whether it might have come from environmental clean-up work SCE&G has been carrying out recently at the site of a former manufactured gas plant adjacent to Huger St. That plant was built in 1906 by Broad River Power Company, a corporate predecessor to SCE&G; it closed in the mid-1950s and was eventually dismantled and replaced bus maintenance facility in the 1970s. SCE&G has been conducting a voluntary remediation of the site for the past several months and expects to complete that project by the end of September.
DHEC will continue to monitor and oversee the cleanup efforts under an existing agreement with SCANA. In an effort to minimize further disturbance of the material while the cleanup is underway, the public is still advised to avoid swimming or wading in that part of the river. "We don't want it stirred up, but also to keep people out of it," said Myrick. "It's a real nuisance to clean up."
A nuisance it may be, but it's not enough to keep everyone on dry land. "As far as I know, it's not gonna stop me," said Bunn. I enjoy paddling too much."