The decision of the Army Corps of Engineers to withdraw support for the state's plan to dump dredge material north of the Chesapeake Bay Bridge has cheered environmentalists and elected officials who have been fighting an uphill battle against the proposal for more than a year.

It has also focused attention on alternatives to disposing of sand and silt dredged from shipping lanes leading into Baltimore Harbor--alternatives that one leading opponent acknowledged can be expensive.

"They got slam-dunked, and now they're back to square one," said Del. Richard D'Amato (D-Anne Arundel), referring to Maryland Port Administration officials who have been seeking approval of the dumping site for more than a year. "Now the search for alternatives takes on a new urgency."

In withdrawing a favorable draft report on the environmental impact of the proposal, Corps officials said they will delay until next summer a final decision on whether 18 million cubic yards of dredged muck can be dumped between Sandy Point State Park and Kent Island, an area known as Site 104.

The Corps acted after biologists from the Environmental Protection Agency and the U.S. Fish and Wildlife Service criticized the draft report for "bias" and for underestimating the impact of dumping on water quality and aquatic life.

Judy Scioli, a spokeswoman for the Port Administration, predicted the Corps' extended review ultimately will prove that dumping at Site 104 is not environmentally harmful.

"Everyone must have confidence in the Corps' report and the science. We have no problem with the decision to refine that analysis and get that confidence," she said.

But opponents, including Rep. Wayne T. Gilchrest (R-Md.) and the Chesapeake Bay Foundation, proclaimed the Site 104 plan dead.

"This is not a question of refining the draft environmental impact statement or tidying up its language," D'Amato said. "The criticisms of the EPA and the Fish and Wildlife Service went right to the heart of the proposal."

Last week, D'Amato circulated legislation to impose a moratorium on open bay dumping until February 2002 and to establish a task force to "thoroughly explore alternative land-base sites." D'Amato claims to have 22 co-sponsors for the bill.

The Port Administration estimates that its efforts to keep Baltimore Harbor open to the biggest tankers and cargo ships will require dredging some 110 million cubic yards of underwater soil over the next 20 years.

"We know it's going to cost more to get rid of dredge material on land," D'Amato said. "The only thing that Site 104 had going for it was that it was cheap."

Right now, the state is placing dredge material at Hart-Miller Island, a man-made island east of Baltimore. But Hart-Miller, which has been used since 1975, is nearing capacity.

This winter, the Army Corps of Engineers began using dredge material to rebuild Poplar Island, a once sinking land mass in the bay near Tilghman Island. But the port administration says that Poplar Island will not be big enough for all the soil dredged over the next 20 years.

"We could do another Poplar Island," D'Amato said. "It's hideously expensive, but you can do it."

The state estimates that it would cost anywhere from $1 to $4 per cubic yard to dump at Site 104. At Hart-Miller Island, the disposal costs run from $2.50 to $5.00 per cubic yard. The cost at Poplar Island is estimated at $11 per cubic yard. So while the Site 104 proposal would cost $72 million at most, a new man-made island might cost upwards of $200 million.

Other possible disposal sites include the Aberdeen Proving Ground north of Baltimore and areas of the Atlantic Ocean.

Gilchrest, who represents Anne Arundel County and the Eastern Shore, says the higher costs are unavoidable.

"Keeping the bay healthy costs farmers more money. It costs developers more money. Why should the port be different?" he said.

Both Gilchrest and D'Amato said that the state will need to obtain federal funding to support on-land disposal efforts.