Gov. James S. Gilmore III vowed today to fight to the U.S. Supreme Court to ensure Virginia's right to restrict garbage imports, even as the state braced for the possibility of new barge shipments bringing New York City trash.

Lawyers for the state meanwhile lost an appeal of Tuesday's preliminary injunction, which has blocked Virginia's new restrictions on garbage barge traffic and trash dumping at the state's seven giant privately run landfills. The laws were to take effect Thursday.

Many state officials and environmentalists said it is now clear that Virginia has few options for slowing the flow of trash unless a reluctant Congress changes course and takes on the issue.

But Gilmore (R) told a radio audience on WTOP that he would continue fighting for the garbage restrictions, which he made a centerpiece of the administration's agenda during this year's General Assembly session.

"We're going to fight hard," Gilmore said. "Virginia cannot become the dumping ground for garbage from New York or anywhere else. . . . We'll take it all the way to the Supreme Court if we have to."

The battles in federal court moved into a second day. Lawyers filed documents regarding the state appeal of U.S. District Judge James R. Spencer's strongly worded ruling in favor of Waste Management Inc., the nation's largest trash company, and other plaintiffs. Spencer's comments suggested that the challenge to the new laws would have a good chance of prevailing at an upcoming trial. Tonight, the 4th U.S. Circuit Court of Appeals refused to overrule Spencer's decision.

As environmentalists' hopes dimmed that the garbage restrictions would survive constitutional scrutiny, they warned that imports could grow sharply in the next few years. Virginia is the nation's second-leading garbage importer, bringing in 4.6 million tons in 1998, a 43 percent increase over the previous year.

Pennsylvania, which has also sought to restrict the trash trade, leads the nation with 9.8 million tons in 1998. But Jim Sharp of Campaign Virginia, an anti-garbage group, said Virginia is catching up.

In legal filings, Waste Management officials said they are vying for 12,000 tons per day in new garbage contracts from New York City; 60 percent of that, the suit says, would come to Virginia, mainly on barges.

Waste Management declined to predict how much New York City garbage may eventually come to Virginia, but Sharp said the annual total could soon grow to 7 million tons or more.

"It's going to double," Sharp said. "The sheer volume of trash means long-term economic and environmental problems."

Waste Management officials confirmed that they are considering when to resume shipping garbage to their $15 million port in suburban Richmond. They stopped in April 1998 to renovate and expand a barge port near one of the company's mega-fills.

"I don't think you'll see us sending a barge down there today," said company spokesman Tom Corbett.

As news of the Spencer's ruling spread, few inside or outside Virginia expressed surprise. States have consistently lost cases when they seek to restrict the booming garbage business, because federal courts consider them a restraint on constitutionally protected interstate commerce.

Pennsylvania Gov. Tom Ridge (R), like Gilmore, is battling out-of-state garbage, but he has focused on lobbying Congress, where a bill to give states more authority over the trade is languishing.

"The governor feels there's enough precedent to show the federal government needs to do this," said Ridge spokesman Tom Charles. "Governor Ridge certainly saw the writing on the wall."

One who did express surprise was Virginia state Sen. William T. Bolling (R-Hanover), the author of the anti-garbage bills. He held out hope for an eventual victory in the state's appeals but said, "If that doesn't work, then I think we're back to the drawing board."

The court, Bolling said, "will have given Virginia an arrowless quiver in terms of letting the state develop a comprehensive waste management plan."

Environmentalist Allen Hershkowitz, of the Natural Resources Defense Council in New York, said Virginia could slow imports by tightening restrictions on what landfills are allowed to take, or it could return to the days when local governments ran their own dumps.

But he said the easiest solution would have been to restrict the giant landfills before they were built, as environmentalists urged.

"To some extent," Hershkowitz said, "Virginia made its own bed, and now it has to sleep in it."

CAPTION: Sen. William T. Bolling (R-Hanover) hopes for victory in the courts.