Source: https://www.postandcourier.com, February 19, 2018
By: Bo Peterson
Oily sludge still oozes into containment wells across the street from the South Carolina Aquarium — at volumes ranging from 50 to 400 gallons per month.
The soil under the former coal tar gasification plant continues to bleed toxins in the ground, long after the contamination was first revealed in the early 1990s and helped lead to the closing of the nearby public housing complex, Ansonborough Homes.
The pollution and its expensive clean-up delayed the building of the South Carolina Aquarium and launched millions of dollars worth of lawsuits and settlements.
The mess could haunt the construction of the International African American Museum nearby, though state regulators say there’s no sign so far of significant pollution there.
The plant is now an SCE&G electric substation on Charlotte Street, a city block-sized lot between Concord and Washington streets.
The sludge oozing under the lot is largely the residue of waste from a plant that once turned coal into gas for street lights and home heating.
SCE&G is responsible for the clean up. The work will continue for the foreseeable future, said Susan Fulmer, federal remediation section manager for the S.C. Department of Health and Environmental Control.
Sludge pollution at the rest of the 18-acre overall site — which regulators dubbed “Calhoun Park” — has been considered cleaned to safe levels since 2006.
But “there was also a coal tar seep along the Cooper River,” said Andrew Wunderlay, of the nonprofit Charleston Waterkeeper. “That was left in place and capped. That’s a big concern: It’s best to remove it to prevent any future contamination.”
His group inspects the shoreline around Harbor Walk and the aquarium a few times a year to keep an eye on it, he said.
“I haven’t seen any evidence of a seep,” Wunderlay said. “We have a number of legacy contamination sites like Calhoun Park, Shipyard Creek or the old phosphate plants on the Ashley River.”
The overall park site today is occupied by the aquarium, the Fort Sumter Visitor Education Center and ferry terminal, office buildings, College of Charleston laboratories, condominiums and parks. The proposed African American museum site sits at its southeastern edge, the farthest away from the substation.

“We don’t have any reason to believe” the grounds underneath the proposed African-American museum are contaminated, said Fulmer, the DHEC remediation manager. DHEC won’t require any testing for the construction, but if pollution is found during the routine construction testing, the state and EPA would be called in, she said.
The sludge is not the only contaminant that’s been found in the Calhoun Park area. The site also once was home to commercial and military wharves, a steam generating plant, a coal tar and pine pitch refinery, a wood treating plant, a paint and and chemical manufacturer and a shipyard, according to the EPA.
Heavy metals and other carcinogens also were found there in a 1993 study. Testing by the EPA and DHEC determined that the sludge “was the major contributor of contamination,” according to the EPA.
The EPA considers the remediation work done there a model.
“Our commitment to site cleanup and redevelopment has supported local tourism, generating economic growth, and improving quality of life,” said Paul Fischer, an SCE&G spokesman.