6 IDR June/July 2019 www.dredgemag.com
Beneficial Use Pilot Project Underway for Jekyll Creek
BY WENDY LARIMER Cottrell Contracting began dredging Je- kyll Creek in Georgia on April 15 under a $12,740,080 contract from the U.S. Army Corps of Engineers Savannah District. The contract, awarded January 23, includes both a beneficial use pilot project in Jekyll Creek and the regular maintenance dredging of other sites along the Atlantic Intracoastal Waterway (AIWW). Cottrell, based in Chesapeake, Virginia, has deployed its 18-inch, 4,200 hp cutter suction dredge Rockbridge for the entire project. Three tender boats, two crane barges, survey boats and a booster pump are also on-site. Devon Carlock, vice president of safety and government relations for Cottrell Contracting, said that the project also requires a total pipeline length of 35,000 feet because material is being discharged into very deep water. Staging, which included laying the pipe and coir logs began at the end of March. The entire maintenance dredging project is removing approximately 900,000 cubic yards of material, with 220,000 cubic yards coming from Jekyll Creek. The dredging and material placement for Je- kyll Creek is part of a pilot project to develop economically efficient and environmentally ac- ceptable methods to manage the dredged mate- rial. Jekylll Creek is the shallowest point in the 160 miles of Georgia's portion of the AIWW and has not been dredged since 1998. The sediment in the creek is fine-grain with low sand content, known as "pluff mud," which has posed a dispos- al challenge and prohibited any dredging. "There were no upland facilities that would hold the volume of material. The onshore and offshore containment facilities were not large enough nor could we afford to transport the ma- terials the needed distance. The closest offshore site is about seven miles away," Georgia Federal Consistency Coordinator for Coastal Resources Division of the Department of Environmental Resources Kelie Moore said. PROJECT PLANNING In designing this pilot strategy, the Corps' Jacksonville and Savannah districts worked with the Corps' Regional Sediment Management Center of Expertise, as well as other federal, state and nonprofit agencies to come up with a plan. The research (and this project) was funded entirely by the Corps, which worked with state partners to come up with monitoring protocol, and placement sites.
Material dredged from Jekyll Creek is being rainbowed onto this wetland area to raise the elevation of the land while maintaining marsh grass growth. Coconut coir logs are placed around the wetland dis- posal area to keep the material from running off into adjacent waterways and marsh. The coconut coir logs for this project required the use of a biodegrad- able netting instead of plastic to ensure the coirs com- pletely degraded.Previous Page