Fairfax County's 3,000-acre Lorton prison property is contaminated with leaking underground fuel storage tanks, tear gas chemicals, asbestos and elevated levels of lead in the water--problems that must be corrected before the soon-to-close D.C. prison can be converted into a vast park and 1,500-home residential community.

The environmental damage to the property, a prison site since 1914, is detailed in a report prepared by a private firm for the General Services Administration, the federal agency that owns the land.

Fairfax officials said they were not surprised by the report's findings and predicted that the need for environmental cleanup will not become a stumbling block for the development of what will be called Laurel Hill.

"There are a number of significant environmental issues, all of which I believe can be cleared up within a reasonable amount of time," said Fairfax County Supervisor Gerald W. Hyland (D-Mount Vernon), who represents the area.

Fairfax supervisors voted in July to convert the Lorton site into a 2,500-acre park, with one area reserved for homes and businesses. The plan was a departure from earlier proposals that called for large retail and office construction.

But the project is far from a done deal.

Part of the deal to transfer the land from the federal government to Fairfax involves a complicated land swap between the GSA and a private landowner who has a parcel in southeastern Fairfax that the government would like. That swap has yet to be finalized, in part because of disputes among the parties about the value of the land.

In addition, there is the question of who will pay for the environmental cleanup at Lorton, which county officials have said could cost several million dollars.

Fairfax officials insist those costs are the responsibility of the federal government, which by law must ensure land is clean before it can transfer title. Federal officials have said the issue of who pays will be determined by Congress.

"The responsibility for cleanup is the federal government's," Hyland repeated yesterday. "This report is being done to give the Congress a handle on what it's going to cost to clean up the site."

Whoever cleans up the land will find problems that have festered for decades, the report says. Among them: 16 underground fuel storage tanks that have been leaking for years; soil and groundwater at a chemical training area that has been contaminated with tear gas; several unauthorized dumping areas; and high concentrations of lead, both in paint and the water supply.

Officials at GSA said work on cleaning up some of the contamination, including the tear gas leaks, has already started.

CAPTION: The Lorton property in Fairfax County, a D.C. prison site that is slated to close soon, is to be converted into a park and 1,500-home residential community.