CHARLESTON, S.C., Aug 23 (Reuters) - A $652 million deepening of the Savannah River shipping channel has been approved by the commander of the U.S. Army Corps of Engineers, according to a report made public on Thursday.
Savannah, the fourth largest container port in the nation according to the Department of Transportation, is among several South Atlantic ports that want to deepen their shipping channels for super-sized container ships expected to come through the expanded Panama Canal starting in 2014.
In July, the Obama administration announced a "We Can't Wait" initiative to fast-track the modernization of five East Coast ports, at Jacksonville, Miami, Savannah, New York/New Jersey and Charleston.
Miami has already received approval for the deepening of its port and dredging is due to begin in early 2013. Charleston's plans are still awaiting approval from the Corps of Engineers, as well as funding from Congress.
The army's final decision on the Savannah project is expected in November.
Actual dredging will take four to five years once it begins. Georgia Ports Authority Executive Director Curtis Foltz has said the entire project was expected to be finished by 2016, though some officials say that is optimistic.
After adjusting for inflation, the Savannah River project's cost is still 20 percent more than Congress has authorized, so Congress will have to appropriate additional funds, according to the report by Lt. Gen. Thomas Bostick, commander of the Corps. Georgia's share of the cost would be $198 million.
About $311 million, or about 47 percent, of the project's cost will be spent on environmental mitigation, including building fish passageways, installation of a "bubbler" system to boost oxygen levels and disposition of dredge spoil.
The Corps will remove 24 million cubic yards of sediment to deepen the waterway from 42 to 47 feet. The sediment will be deposited in existing upland containment areas and disposal sites approved by the Environmental Protection Agency, the report said.
A federal lawsuit by environmental groups to stop the dredging argues that the sediment will contain hazardous cadmium and dumping it on South Carolina shores will require a pollution permit from the state.
Environmentalists are also concerned about the impact of dissolved oxygen depletion in the river on endangered fish, said Blan Holman, attorney with the Southern Environmental Law Center.
"The Corps and Congress have steadfastly refused to ask if Savannah is the best deepwater option in the South Atlantic," Holman said on Thursday. "They'd rather borrow billions to dredge all the harbors, then let foreign shipping lines play our ports off one another."
A spokesman for the Corps would not comment on the lawsuit.
Environmental mitigation could begin in 2013, depending on funding, Savannah District Corps spokesman Billy E. Birdwell said on Thursday.
It will include the $14 million removal of a Confederate ironclad warship, the Georgia, which was sunk in the middle of the river in 1864 to prevent it from falling into Union hands. (Editing by David Adams and Todd Eastham)