One step closer to dredging: Army Corps of Engineers retrieves offshore samples for testing
Another task done, plenty more to go. The U.S. Army Corps of Engineers, Charleston District retrieved rock core samples from sites in the Charleston Harbor’s entrance channel to help better grasp costs of the deepening project.
This was the final step of the feasibility study. The feasibility report and environmental impact statement is on track to be released next summer with the final report submitted to Congress by September 2015.
Deepening the harbor was one of President Obama’s “Can’t Wait” iniatives because of potential benefits to our local economy, as well as national impact.
Sampling took place at 49 different sites, stretched 15 miles offshore and occurred as deep as 62 feet below the water. After a news conference at Sunrise Park in James Island, the samples were sent to a laboratory in Marietta, Ga.
“They’ll draw conclusions on those lab results about how easily those materials can be dredged by traditional dredging technology – something that doesn’t involve blowing things up – and that will figure out our costs,” project manager Brian Williams told media members. “That’s really what this is about. We’re trying to come out with the most accurate representation of the cost to dredge Charleston Harbor.”
Williams held a fragment of cocina, which crumpled slightly at the touch. Cocina, a type of sedimentary rock, is made up of shell fragments, silk, sand and clay that have compacted over time. He said there’s a “very low probability it will need to be blasted.”
“There’s still uncertainty, and that’s what we’re trying to reduce,” he added. If dynamite is needed underwater, it will further complicate the matter environmentally and increase costs.
“We had made the assumption from the beginning that we would not encounter anything that needed to be blasted,” Williams said. “Our assumption to this date has been held up from what we’ve seen in the field.”
Results from Georgia are expected in the coming weeks. Williams added that “optimistically,” once the Corps of Engineers receives the green light to dredge, it could take between three and four years to deepen the shipping channel by five feet to a total depth of 50 feet.