FREDERICK - In a costly and unusual step in its hunt for the anthrax killer, the FBI began draining a 1-acre trout pond in a Frederick County forest yesterday, hoping to find discarded biological equipment or telltale anthrax spores on its muddy bottom.
The project, estimated to cost about $250,000 and take several weeks, began yesterday morning after a state biologist told investigators how to avoid trampling a rare yellow-fringed orchid and other endangered species in the area.
The search follows the discovery in the pond last winter of a plastic box that some investigators believe may have been used by the person who mailed anthrax-laced letters to news media organizations and U.S. senators in 2001. The attacks killed five and sickened at least 17.
The object appeared to be a homemade glove box, a biological safety device fitted with gloves to protect someone working with dangerous germs, though no gloves were attached. Anthrax tests on a rope also found in the pond have been inconclusive, according to a law enforcement official.
FBI agents began searching the woods last fall as a result of a tip suggesting that a former Army bioterrorism expert, Dr. Steven J. Hatfill, might have thrown biological equipment in the pond. The work drastically accelerated in December and January, when scores of agents combed the woods, and divers cut through the pond ice.
Hatfill, who worked at the Army's biodefense center at Fort Detrick from 1997 to 1999 and lived near the base until last summer, has been intensely scrutinized by the FBI's "Amerithrax" task force for more than a year. Surveillance teams follow him whenever he leaves his Washington apartment.
One official who talks regularly to investigators said the task force is divided into one faction that believes Hatfill is still a promising suspect and another that is frustrated by the failure to find substantive evidence against him. "Even the ones who favor draining the pond aren't all that certain they'll find anything," the source said.
Hatfill has publicly and repeatedly protested his innocence, as he did again yesterday.
"When Steve heard the news this morning, he just chuckled and shook his head that they would waste all that money," said his spokesman, Pat Clawson. "They can search every pond in Maryland and drain the Pacific Ocean and they won't find evidence linking Steve Hatfill to the anthrax attacks, because there is no such evidence. On the other hand, if this will help further establish Steve's innocence, we welcome it."
At midday yesterday, FBI agents, postal inspectors and contractors were gathered at the rain-swollen pond, known locally as Whiskey Springs Pond, as generators and pumps rattled away.
All-terrain vehicles were parked near several large tents. People authorized to pass the roadblock on Gambrill Park Road to approach the site were wearing "Fire Pond Alpha" identification cards specially manufactured for the project.
Whiskey Springs is one of a dozen fire ponds in the Frederick Municipal Forest dug by the Civilian Conservation Corps in the 1930s to provide water to fight forest fires, locals say. The city-owned watershed is about eight miles northwest of Frederick, bordering on Gambrill and Cunningham Falls state parks.
The thick hardwood forest is a favorite of fishermen, mountain bikers and hikers. It was an incongruous place to find the yellow crime scene tape that was strung from tree to tree, blocking access to Whiskey Springs and parts of four other ponds.
Frederick County workers were laying stone on a new gravel road through the muddy woods to the pond, the second such road they have built for the FBI since December.
"It's a very unnatural activity in a very natural setting," said Richard McIntire, a spokesman for the Maryland Department of the Environment, which has assigned a wetlands specialist to advise the investigators. "We're determined that when all this is over, the area will be returned to the state that evidently has made it a very special place for the people who live around there."
McIntire said no permits were required to drain the pond, because the work "is considered an emergency-type situation" and because the estimated 50,000 gallons of water will be pumped back "into the immediate environment," meaning local woods and streams.
In addition to the Maryland Department of the Environment, the state Department of Natural Resources had specialists at the scene yesterday to advise the FBI and its engineering contractor, Phillips and Jordan Inc. of Knoxville, Tenn., on minimizing environmental damage and protecting rare plants and creatures, including the wild orchid and a species of newt.
The FBI and the office of Frederick Mayor Jennifer P. Dougherty assured the public that the city's water is safe to drink.
"Over 300 soil, water and sediment tests have taken place in the course of this investigation," the mayor's statement said, and daily sampling continues.
After FBI divers left the pond over the winter, state fisheries workers stocked Whiskey Springs Pond with about 1,300 rainbow trout.
Many of the trout died because of poor water quality, but it had nothing to do with anthrax, said Heather Lynch, a DNR spokeswoman. DNR workers will monitor the pond as the water drops and may move the fish elsewhere if numbers warrant, she said.
Investigators are believed to be looking for more equipment that might be linked to the anthrax letters. In addition, outside experts say, they will probably sample the muck on the bottom extensively in search of anthrax spores.
"A small quantity of anthrax would be hundreds of thousands or even millions of spores," said Dr. William M. Nelson, president of Tetracore, an anthrax testing company, who did anthrax testing for the FBI and military while in the Navy. "You could take 1,000 samples from the bottom and try to grow it. All you need is one spore."
He said investigators are likely to use a specialized growth medium designed to kill ordinary pond bacteria but enhance the growth of anthrax. If anthrax does grow from a sample, he said, it would be possible to sequence its DNA and see if it matched the Ames strain of anthrax used in the attacks.
The Ames strain is used by the Army at Fort Detrick to test vaccines. The strain was first isolated from a dead cow in Texas in 1981. It is not found in nature in Maryland, scientists say.