The U.S. Army Corps of Engineers, Philadelphia District, and its contractor Great Lakes Dredge and Dock Company began rock blasting operations last month as part of the project to deepen the channel of the Delaware River.
This phase of the program involves fracturing of rock by controlled underwater blasting so it can be removed mechanically.
After blasting, rock is being removed by using mechanical dredging (typically bucket dredging) and placed at Fort Mifflin.
This capital development project involves dredging as needed within the existing 40-foot Delaware River federal navigation channel to deepen it to 45 feet from Philadelphia Harbor, Pa. and Beckett Street Terminal, Camden, N.J. along a 102.5-mile distance to deepwater in the Delaware Bay.
More than 16 million cubic yards of material must be removed during initial construction. Of that amount, approximately 12 million cubic yards of silt, clay, sand and gravel will be dredged from the river portion of the project.
The remaining 4 million cubic yards is primarily good quality sand from the Delaware Bay, half of which is being dredged and placed for initial construction of the Corps’ coastal storm damage reduction project (dune and beach nourishment) at Broadkill Beach, Del.
The Delaware River dredging scheme is slated for completion by the end of 2017.