A Confined Aquatic Disposal (CAD) cell will be constructed and portions of the Boston Harbor Federal Navigation Project main ship channel in Boston, Mass., will be dredged under the terms of a $12.8 million contract issued recently by the U.S. Army Corps of Engineers, New England District.
Work will be accomplished by Great Lakes Dredge and Dock Company (GLDD), Inc. of Oak Brook, Illinois. The contract was awarded on September 30, 2016.
The project will take approximately one year to complete and the dredging work is scheduled to start in late December 2016.
Approximately 1 million cubic yards of mostly Boston blue clay will be dredged to create a CAD cell, with proposed cut depths up to elevation -90 feet Mean Lower Low Water (MLLW) in the 40-foot deep Main Ship Channel.
The material dredged to create the CAD cell will be placed at the Massachusetts Bay Disposal Site (MBDS) approximately 20 miles offshore of Boston Harbor.
Once the CAD cell is constructed, maintenance dredging of approximately 805,000 cubic yards of silty material from portions of the 40-foot Main Ship Channel, the 40-foot deep Inner Confluence, and portions of the 35-foot deep channel, will be placed into the newly constructed CAD cell.
Dredging will be accomplished by mechanical means and dredging of the silty material will require the use of a closed environmental bucket.
The project will be managed by the Corps and all work will be accomplished under the supervision of a Corps’ Quality Assurance Representative to assure compliance with contract requirements.