But the new system, which would take the next two years to implement, probably will not save any money - at first. Bloomberg's trash plan will cost the city a few hundred million dollars. Each of the eight existing marine transfer stations will have to be expanded, to varying degrees.

In addition, a new $35 million one will have to be built on Staten Island - now the only borough without one. And 10,000 containers at a cost of around $1,000 each will have to be bought or built.

But Bloomberg hopes that once the trash is compacted, put on barges, and loaded onto ships or rail cars, more localities will be willing to burn or dump the garbage in landfills. That will put the city in a better bargaining position than it is now, when the bulk of the trash travels by truck.

Virginia and Pennsylvania are two of the only states that accept the city's trash. Private garbage collectors, who haul away as much as 13,000 tons of trash each day from the city's commercial enterprises, dump it upstate and in New Jersey. NEW STRATEGY BASED ON WATER ACCESS

"Do I think it is going to take the cost of sanitation from $1 billion to $600 million, which is what it was before Fresh Kills closed? I don't think there's any realistic chance of that," Bloomberg told City Hall reporters.

The Fresh Kills landfill on Staten Island, reviled as the world's largest garbage dump, was closed in March 2001 after years of protests by local politicians, residents and environmentalists. Staten Island's new marine transfer station, however, might be built near Fresh Kills, the mayor said. But it will not have to handle trash from other boroughs.

Bloomberg's new strategy capitalizes on one of the city's natural advantages, its waterways, which touch all five boroughs. Noting how truck traffic will drop, Bloomberg added: "We are not going to continue to give our kids lung diseases, no matter what the economic cost - that's the bottom line."

Ex-mayor Rudolph Giuliani tried hard to solve the city's trash problems but found it difficult to find other localities willing to take on the role of New York City's garbage dump. Ex-Gov. Christie Whitman, trying to safeguard her state, once said the city could "drop dead."

In contrast, New Jersey Gov. James McGreevey, who did not favor one alternative Giuliani explored - building a transfer station in Linden, New Jersey - said he would work with Bloomberg. "The mayor's decision provides an opportunity for Port Elizabeth/Port Newark to increase capacity as a prospective center of operations," McGreevey said in a statement.

Figuring out what to do with the trash produced by the city's 8 million residents has been one of the thorniest problems facing the new mayor - who already has riled environmentalists by suspending the recycling of plastic and glass as a cost-cutting measure. The city faces a $5 billion budget gap because of the national slowdown and the Sept. 11 air attacks.