Method to the muck Charleston Harbor vitality depends on dredge disposal site in Cooper River

Motorists traveling on the Don Holt Bridge pass over the Cooper River and, perhaps without notice, a swath of parched muck that will play an important role in the proposed deepening of Charleston Harbor.

The span that links Daniel Island with North Charleston also crosses over the Clouter Creek Disposal Area. The 1,400-acre federal property is used by the Army Corps of Engineers' Charleston District as its main storage site for the soupy sediment pulled from the floor of Charleston Harbor, helping keep the waterway deep enough for safe passage of cargo ships and other large vessels.

Plans call for the Clouter Creek property to house some of the sediment from a proposed $300 million project to deepen the harbor, said Glenn Jeffries, public affairs officer for the Army Corps' Charleston office.

The State Ports Authority wants to deepen the local shipping channel to about 50 feet from 45 by 2018 so it can accommodate the mega-sized cargo ships that will be to get though the soon-to-be expanded Panama Canal.

Using Clouter Creek as part of the project is an about-face from the Army Corps' initial plan to send all sediment miles off-shore into the Atlantic Ocean.

"More recently and with more specific information regarding the types and quantities of material likely to be encountered during deepening, the Corps estimates that it can continue to effectively manage the Clouter Creek Disposal Area and accept approximately 20 percent of the deepening sediment into Clouter Creek and other inland disposal areas," Jeffries said.

She added that using Clouter Creek and a disposal site owned by the SPA on Daniel Island will save an estimated $41 million because it will require less equipment and time to transport the material.

"Clouter Creek helps make this project much more competitive for approval and funding," Jeffries added.

Jim Newsome, president and CEO of the SPA, agreed.

"Clouter Creek, a site we utilize in partnership with U.S. Army Corps of Engineers, provides an adequate, cost-effective location to dispose of dredge material," Newsome said. "The site will become increasingly important as we move forward with our harbor-deepening project."

That project is currently before the Army Corps, which is studying the feasibility of deepening the harbor. The agency's recommendation for the deepening project will be released next year.

As for Clouter Creek, the area has been piling up with dredge sediment for several decades.

Each year, Charleston Harbor's 36-mile federal shipping channel collects sediment that needs to be removed to maintain the required 45 feet of depth.

The waterway that snakes up the Cooper and Wando rivers costs the Army Corps as much as $12 million each year to clear what is more than 2 million cubic yards of sediment, officials have said.

In addition to Clouter Creek and the Daniel Island site, dredge materials are handled at Drum Island, a parcel of land under the Ravenel Bridge, as well as Morris Island and Yellow House Creek, a site off the Cooper River. The SPA owns dredge sites on those latter three spots, in addition to its Daniel Island disposal property.

"Dredging is a critical, ongoing process that ensures large shipping vessels calling on the Port of Charleston can access our terminals," Newsome said.

That explains the role of Clouter Creek today.

What may look like a mosquito-ridden area of parched earth and lakes actually represents various stages of the dredging process.

About 1.2 million cubic yards of dredge sediment each year is dumped at the site each year. The area costs the Army Corps as much as $2 million annually to maintain, Jeffries said.

"It is a critical piece of our dredging strategy." she said.

Sign up for our new business newsletter

We're starting a weekly newsletter about the business stories that are shaping Charleston and South Carolina. Get ahead with us - it's free.

The Clouter Creek area is made up of four areas known as cells. Each usually takes seven years before it reached capacity, officials said.

"This is very slow and very methodical and labor-intensive, and it has been designed over a very long time to capitalize on the condition of the material," said David Warren, civil works project manager for the Army Corps.

The tedious task require several workers on the site, along with equipment such as backhoes and cranes that they use to move and otherwise handle the muck.

The process starts with the sediment sucked from the bottom of the harbor and piped to the site. The material is a mixture of sand, mud and other material that creates an unstable surface that has a quick-sand texture, said Frank Russell, quality assurance representative.

So the area is no playground.

The Army Corps htries to discourage outsiders by posting several "No trespassing" and "Warning" signs.

"Eventually, it will dry up enough for someone to walk on it, but initially, if you go out there . you won't have to walk very far before you're going to start to feel the unsettling," Russell said.

The drying process can take up to a year, and the landscape wind up looking like a barren desert.

But all the material isn't dry, so construction crews create ditches to help drain the remaining moisture before the material is used to create dikes for a new wave of dredge sediment.

The area also is home to swarms of mosquitoes, and wildlife such as birds, bobcats and deer. And what's pumped from the dredge pipes is not always limited to sediment. Russell said he's seen bikes, wrenches and animal carcasses.

"Whatever gets tossed from a boat or ship ends up down there. ... I've also seen some large shark teeth, too," he added.