FBI begins draining Maryland pond in anthrax probe

The FBI announced Monday that it has begun to drain a pond near Frederick, Md., as part of the bureau's investigation into the 2001 anthrax mail attacks.

"The FBI and the U.S. Postal Service are conducting forensic searches on public land located near the city of Frederick, Maryland," the FBI said in a press release. "To facilitate the search activity, one pond will be drained."

The area surrounding the 1-acre, 50,000-gallon pond will remain classified and restricted during the investigation, the city of Frederick said in a press statement today. This stage of the bureau's investigation is set to last up to four weeks, after which the FBI will fully restore the pond and surrounding area, according to the Frederick release.

The FBI is unsure as to how long it will take to drain the pond, bureau spokeswoman Debbie Weierman told Global Security Newswire Monday.

A set of ponds located in the Maryland forest has been a focus of the FBI's investigation into the attacks since late last year when the bureau first searched the ponds using divers. The Washington Post reported last month that those pond searches uncovered several pieces of laboratory equipment, including what could be a box that would allow someone to manipulate material inside it while wearing gloves.

The searches also discovered a piece of rope, which investigators initially believed could have been used to anchor the box in the pond, USA Today reported last week. Initial tests indictating traces of anthrax on the rope were later reversed, according to USA Today.

The stretch of forest where the pond being drained is located is near the former home of Steven Hatfill, a former Army biologist who has been the public focus of the FBI's investigation into the anthrax attacks. Hatfill has repeatedly denied any involvement in the attacks.