“What’s down there has been a subject of discussion for many, many years,” said Berresford, a South Carolina Department of Health and Environmental Control engineer associate. “But it’s never been thoroughly investigated until now.”
Scientists working from boats are midway through a project to collect and analyze more than 500 samples of sediment that has washed into the 250-acre lake since its creation around 1870.
“They’ll be testing for metals, PCBs, even mercury,” Berresford said. “It will give us a better picture of what is down there.”
The pond is part of the Horse Creek Valley, named for the 24-mile tributary of the Savannah River that powered the region’s industrial revolution more than a century ago. In its heyday, the creek was flanked by dozens of industries, dominated by the textile trade.
“Horse Creek feeds the lake, and the mills and other industries all discharged to that creek, even before the pond was built,” he said.
Suspicions and small-scale tests in the past — including an investigation by the Environmental Protection Agency — have found varying levels of contamination that warranted a broader look, he said.
The current inquiry, begun in early January, is a joint effort between DHEC and the pond’s owner, Aiken County.
The project included transecting the pond into 200-foot grids and obtaining a sample from each one. Technicians use a vibrating probe to carefully extract sediment all the way down to the area’s original, undisturbed earth. The lake’s depth ranges from 3 to 18 feet, with layers of sediment from 2 to 5 feet.
In addition to defining the concentration of any contaminants, the sampling will also create a vertical profile to determine how far into the sediment the material can be found.
“We’ve been making great progress so far,” Berresford said. “We might even finish this part of it within the next two weeks.”
Once the samples have been collected and studied, DHEC and Aiken County hope to schedule a public meeting later this year to share the results with the community.
The mere presence of contamination in sediment does not necessarily pose a health hazard. “We have a long history, going back 15 years, of surface water samples that have come back clean,” Berresford said.
The lake, like many other waterways in the region, is under a state fish consumption advisory for mercury that recommends limits on the number of fish that can be eaten — and suggests that largemouth bass from the pond not be eaten at all.
Officials say it is far too early in the study process to determine whether remediation is needed or warranted at Langley Pond, or whether the contaminants encapsulated in its buried sediment pose a hazard.