Along Potomac, an Ecological Mystery Surfaces

"You have this sense that you're really in this really wild place," said Matthew Logan, president of the Potomac Conservancy. "And then" -- he whistled, watching an imaginary barrel pass -- "industrial society floats by."

Environmentalists' attempts to trace the barrels have led only to frustration.

Gina Mathias, of the Alice Ferguson Foundation, entered words printed on one barrel into an Internet search engine and found a manufacturer's name: Plasti-Drum of Lockport, Ill.

But then she hit a wall: Plasti-Drum ceased to exist in 1986.

The company was sold, and then sold again, and wound up in the hands of the Greif company in Delaware, Ohio, which has no idea which customers in the Potomac watershed might have purchased Plasti-Drum barrels.

"Not after so long," Deb Strohmaier, a spokeswoman for Greif, said.

Ed Merrifield, an environmentalist whose title is Potomac riverkeeper, got a little further up the chain.

He had noticed that many barrels seemed to have once held fruit juice, and he thought that they might be traced to the McCutcheon Apple Products company in Frederick.

Robert McCutcheon III, the company's president, said his business does buy grape juice concentrate in this type of barrel.

But McCutcheon said that his company re-sells the empty barrels by the hundreds and that the public buys them for $9.95 each.

From there, the barrels are believed to be used as floats in Potomac River docks and piers, or as trash cans or feed troughs on farms.

All those uses could put the barrels in the river, environmentalists have said, because strong spring floods can break off docks or wash away the contents of a streamside farm or front yard.