Staff Report
Published July 15, 2010

S.C. Electric & Gas Co. has agreed to remediate a tarry black substance discovered at the end of June in the Congaree River bed just south of the Gervais Street Bridge.

Testing of the substance indicated it is coal tar, likely created during the production of manufactured gas in the early part of the last century. At least two manufactured gas plants operated in the vicinity during the early 1900s, including one that belonged to a corporate predecessor to SCE&G.

The S.C. Department of Health and Environmental Control agreed saying, “all current evidence indicates the coal tar in the Congaree is from historical releases prior to the closing of downtown Columbia’s last manufactured gas facility in the 1950s.”

Although it may never be determined with certainty where the coal tar originated, SCE&G President Kevin Marsh said his company is committed to ensuring that the deposit is fully remediated.

“It’s simply the right thing to do,” Marsh said. “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.”

The time it will take to remediate the river or the costs are yet to be determined, said SCE&G spokesman Robert Yanity. It will depend on the extent of the affected area.

The next step is to work with the S.C. Department of health and Environmental Control to develop a remediation plan, he said.

SCE&G environmental experts will work closely with the DHEC to identify the specific areas of the river bed where coal tar has been found.

“Although manufactured gas production in Columbia occurred between 55 and 100 years ago, we’ve just learned about this situation,” Marsh said. “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. 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 know and understand what we’re doing every step of the way.”

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 Street.

That plant was built in 1906 by Broad River Power Co., a corporate predecessor to SCE&G. It closed in the mid-1950s and was eventually dismantled. A bus maintenance facility was constructed on the site 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.

“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,” DHEC said.

While it has been confirmed that the tar in the river bed did not result from SCE&G’s current remediation efforts on Huger Street, and is not the result of any recent or ongoing release, it is consistent with the coal tar created by the manufactured gas plants that operated throughout Columbia from the late 1800s until the 1950s.

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, DHEC said.