Virginia health investigators told Dulles International Airport officials yesterday that barrels of jet fuel and other flammable liquids have been illegally dumped in a remote, wooded area on airport property for the past several years.

Officials for the Virginia Bureau of Hazardous Waste Management ordered airport officials to halt the dumping and gave them 90 days to dispose of 40 to 45 drums accumulated at the site. The drums are now sitting partially covered in a pit in an isolated area at the southern end of the airport near the Fairfax-Loudoun County border.

"An airport which has all kinds of jet fuel needs to store the fuel properly," said Wladimir Gulevich, director of the state waste-management bureau. "Materials like jet fuel and solvants are hazardous because they are ignitable. They are more of a safety problem than a toxic waste problem."

Gulevich said state officials have not yet determined whether Dulles will be fined for the illegal dumping.

"In general we prefer to clean up things rather than drag it out and start a paper war," said Gulevich.

Airport manager Dexter Davis said yesterday that he will order an immediate cleanup of the area.

"We shouldn't have done it," Davis said. "We did it quite innocently. . . . If I'd known it was against the law, we wouldn't have done it."

The barrels, containing materials such as paint thinner, waste jet fuel, crude oil and used motor oil, have been hauled at irregular intervals during the past three years to the pit several hundred yards from a fire-drill field used for training airport firefighters, Davis said.

According to Davis, some of the contents of the 55-gallon barrels of flammable materials have been ignited at the nearby fire drill field for training exercises. Gulevich said that although he is not familiar with the Dulles practice drills, such procedures are permitted by the state under certain circumstances.

Davis noted, however, that many of the barrels of materials have not been used in drills, and some have been lying in the field for almost two years.

He said the airport also has allowed the Smithsonian Institution to dispose of some of its flammable waste at the site during the past several years. Davis said that in the past few years, the Smithsonian has dumped 30 to 40 barrels of flammable liquid in the pit.

Two weeks ago airport officials decided to clean up the drill field and partially buried many of the unused barrels of liquids with a bulldozer, Davis said.

"Nobody said, 'Hey, this is wrong, let's try to cover it up,' " Davis said, adding he did not know the airport was violating state safety regulations.

But state health officials said the drums are being disposed of illegally and cannot remain on the site.

Davis said that the dump site, located off an interior road about 1 1/2 miles from the airport boundary, "doesn't present any immediate danger. . . . If it blew up, it isn't going to hurt anything but a crow."

"We were not taking a steady stream of hazardous material there," said Davis.