A lighthouse stands on Plum Island. (Oct. 6, 2010)

A lighthouse stands on Plum Island. (Oct. 6, 2010) Credit: Ed Betz

A final federal environmental report released Tuesday recommended that Plum Island be sold to a private party and that it could support as many as 500 homes, even as it identified 24 former waste sites still undergoing cleanup.

The impact statement, another possible step toward the closure of the East End laboratory that employs 100 scientists and 300 support personnel, didn't pick a preference among three development options it weighed.

Those options are turning the government testing laboratory into a private research facility or business park; selling the island, a mile and a half off Orient Point, to a housing developer, for one to 500 homes; or making it into a nature and conservation preserve.

Further environmental review and cleanup would still be needed before it's sold to a private individual, the report said.

"Information from these [environmental] review processes will be critical in informing the terms and conditions of the sale," said Patrick Sclafani, spokesman for the General Services Administration, which is handling the sale.

The Suffolk County Planning Commission this month called on further disclosure of environmental contamination at Plum Island, which has for decades been used to study animal diseases.

The 512-page report said 87 former waste sites have been identified at the Plum Island facility. While some have been "determined to require no further action" by state environmental officials, the Department of Homeland Security "is continuing its ongoing voluntary program of site investigation and remediation" at 24 of the sites.

Rep. Tim Bishop (D-Southampton) said the report "shows that the island's unique natural and historic resources are ideally suited for adaptive re-use of the current facility for research and preservation of the undeveloped areas."

He said he will introduce a bill to reverse the requirement in current law that Plum Island be sold.

The U.S. Department of Homeland Security wants to replace Plum Island with a new research lab in Manhattan, Kan., the National Bio and Agro-Defense Facility. That facility is estimated to open in 2019, according to the environmental impact statement, with Plum Island to be shut in 2021.

Environmentalists have argued that the land should be retained by the U.S. government.

"Selling a publicly owned, rare and precious resource to a private developer is reckless and imprudent," said Adrienne Esposito, executive director of Citizens Campaign for the Environment, Tuesday.

Southold Town created new zoning for the island, which would prevent single-family homes or commercial businesses from being developed there. Local real estate experts said there would be demand for the island, but testing is needed. "Some serious scientific tests would need to be done before anyone would be attracted to it as a residential development," said Adam Miller, a real estate attorney who specializes in the Hamptons and North Fork. "But stranger things have happened. The location is incredible. And it's an island. They're not making any more islands. Someone will be attracted to it."