Delaware Attorney General Joseph R. "Beau" Biden 3d filed suit in U.S. District Court for the District of Delaware seeking a preliminary injunction to halt dredging that could begin as early as January until proper Delaware permits are obtained.

The Corps' decision to proceed is a "direct challenge to the territorial authority" of Delaware and "violates federal and state law," Biden said.

On Oct. 23, Jo-Ellen Darcy, assistant Army secretary for civil works, decided to proceed, although Delaware denied a permit for the work in July, eight years after the Army Corps applied for it.

Darcy concluded, as had her predecessor, John Woodley, in April, that federal supremacy trumped the need for state approval in order to protect interstate navigation.

Environmentalists and Delaware officials are concerned that dredging the 103-mile span would harm aquatic life such as the blue crab and sturgeon, and the sandbar shark, which recently became a federal protected species, the lawsuit said.

Environmental officials worry about stirring up silt and sediment and the impact on air and water quality of blasting the riverbed five more feet.

Gov. Rendell, a longtime proponent, said last night that the lawsuit ignored the wishes of Delaware's two largest Chambers of Commerce, which have asked Gov. Jack Markell to support dredging.

Rendell said the latest environment assessment in April supported 19 years of studies that "there is no harm done by dredging." The river channel is dredged every year to maintain the 40-foot depth, and "no one has ever sued."

Rendell said the Port of Wilmington favors the dredging, as do the unions. "But notwithstanding the suit, we will still extend the olive branch to Delaware and ask them to participate with New Jersey and Pennsylvania in oversight of this project," he said.

Gov. Corzine, who faces a tight race for reelection Tuesday, said this week that he directed his attorney general to "prepare legal action to stop this irresponsible move" by the Corps.

Gov. Markell yesterday called the Corps' decision to move ahead "wrong" and said the "project's environmental and economic development effects" must be "fully considered."

The first section of river to be deepened is an 11-mile stretch in Delaware state waters.

The Corps on Oct. 9 awarded a routine maintenance contract to maintain the river's current depth of 40 feet. Under that contract, the Corps has up to 60 days to exercise an option to begin the deepening work. A notice to proceed could come after Dec. 25.

The Corps has said it would proceed unless barred by litigation.

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