The classified ad might read: "Island for sale. Gem of a property, teeming with fish and wildlife, only a two-hour drive from nation's largest metro area. Features power plant, sewage treatment. Ripe for development."

What it might not say: "Site of animal disease research and germ warfare testing; old Army coastal defense post."

Plum Island held an open house of sorts for environmental leaders Wednesday as the federal government proceeds with plans to relocate its 50-year-old animal disease research laboratory to Kansas and sell the 840-acre pork chop-shaped island off the eastern tip of New York's Long Island.

The laboratory is modern and would not look out of place on any college campus, but the rest of the island is largely undeveloped with freshwater marshes, pristine beaches and seals resting on huge rocks just offshore. There is also an 1869 lighthouse (no longer in use) and buildings from a U.S. Army base that closed after World War II.

The visit was part of an ongoing effort by Plum Island brass to end the suspicion surrounding the island made famous in a 1997 Nelson DeMille best-selling book of the same name, and its mention as a possible home for Hannibal Lecter in the film "Silence of the Lambs."

"There has been, in the past, more secrecy about the facility," said lab director Dr. Larry Barrett, who noted more than a dozen community groups have visited this year. "This facility is not a threat to the nation, it's not a threat to anyone. The job here is to protect our nation against attacks on our livestock."

Agriculture Department scientists perform the lab studies, but the Department of Homeland Security has overseen the island and its security since 2003.

Because the island is a potential target for those who might want to steal dangerous pathogens or wreak havoc, visitors must undergo FBI background checks and all bags are inspected before anyone is permitted onto a ferry for the 1.5-mile trip. Armed guards check visitors leaving the island to ensure no food or other material is carried back to the populated areas.

Environmentalists peppered Plum Island officials with questions about sewage treatment, groundwater testing, whether surveys have been conducted on the impact a sale might have on wildlife and concerns about possible contamination. The officials were short on specific answers but promised a follow-up meeting.

"I was a little surprised by the lack of detailed environmental information so that was a little disappointing, said Adrienne Esposito, executive director of the Citizens Campaign for the Environment. "So we still have the same concerns. The same concerns about groundwater, soil, wetland contamination. We need to make sure that public health is protected as well as the natural assets."

Most of the environmentalists said they would support a research and development facility to replace the laboratory but were adamant that most of the island should remain in its natural state.

"It would be a terrible insult to the millions of people who live within an hour's drive of the (Long Island) Sound for this to be developed as a playground for the few, as opposed to making it a managed and loved place for the many," said Curt Johnson, program director of a group called Save the Sound.

He said the island has been identified as an exemplary site for fish and wildlife. Great Gull Island and Little Gull Island, both nearby, combined with Plum Island have a large population of nesting roseate terns, an endangered species, he added.

"This is an incredible snapshot of what Long Island Sound looked like hundreds of years ago," Sandy Breslin, director of governmental affairs for Audubon Connecticut, said as she watched seals resting on rocks.

The General Services Administration, which is responsible for selling the island, is compiling a draft environmental impact statement, a preliminary step for any sale. Expected last month, the statement has been delayed until late November or early December to allow input from the Environmental Protection Agency and the Fish & Wildlife Service, GSA spokeswoman Paula Santangelo said.

Documents, some obtained this year by The Associated Press under the Freedom of Information Law, reveal that hundreds of tons of medical waste, contaminated soil and other refuse have been shipped off the island. Other island sites have been cleaned in compliance with federal regulations.

And the U.S. Army Corps of Engineers determined in 2006 that no munitions or ordnance remain from the Army base. As late as 2007, New York government inspection reports said there is no environmental threat on the island.

Despite talk of selling Plum Island, officials said a new lab in Manhattan, Kan., is not scheduled to open until 2018. Still pending is a congressional risk assessment of Homeland Security's decision to move the animal disease lab there; some lawmakers question the wisdom of studying dangerous pathogens in the so-called Beef Belt. DHS has determined that an accidental release of foot-and-mouth disease would have a $4.2 billion impact on the economy, regardless of the lab's location.

Alan Schnurman, a real estate developer in the Hamptons on Long Island's east end, said he has heard estimates that Plum Island could fetch as much as $50 million.

"As a high-end real estate project, whether it's developed as a resort or for high-end individual homes, Plum Island is very appealing to a certain segment of the population," Schnurman said. "They should develop the area where the lab is located and set aside the rest for environmental purposes."