Bryan R. Butler has come up with a possible solution for a national scourge -- pond scum.

That may not sound like such a monumental problem, but the green goo under attack by the University of Maryland Cooperative Extension agent can clog irrigation lines and inhibit aquatic life, as well as make ponds smelly and unappealing.

His solution? Throw in some bales of barley straw. Something seeps from the straw into the water, he theorizes, and makes the algae disappear.

"They're kind of like a giant tea bag," said Butler, who works for the Cooperative Extension agency in Carroll County. Word of his early success with the method has brought him inquiries from across Maryland and the country -- from local and state officials, universities, homeowners associations, farmers and individual pond owners.

"They're just really happy there may be a way to deal with this problem that doesn't involve chemicals," Butler said.

There are commercially available solutions for reducing algae, but they contain substances like copper sulfate, which could harm the environment, Butler said. Other nonchemical methods of algae control have been tried, but at least one local pond manager says they don't seem too be effective.

"We tried carp, but they just couldn't make a dent in it," said Peter Loizeaux, of the Virginia-Maryland Regional College of Veterinary Medicine, on the College Park campus.

There is a pond on campus that has been plagued for years with an increasingly severe algae problem, for the same reason algae is a problem elsewhere -- fertilizer-saturated runoff.

Loizeaux tried four of Butler's barley straw bales on the 150-by-40-foot man-made pond and found it worked -- the thick layer of algae largely disappeared. Loizeaux and his colleagues don't quite understand why the algae went away, so, scientists that they are, they are not quite ready to concede that the bales were the cause.

"Maybe it was the absence of rain, maybe something with the sunlight -- who knows?" Loizeaux said. "We'll try it again next summer."

Butler, whose work is funded by the University of Maryland, is trying to come up with the rigorous proof that is so far lacking. He is studying the barley straw effect both in the field and in the lab and hopes to publish his results this winter.

Butler heard at a pond-water management seminar that the technique is widely used in Great Britain, largely because of an accident. As he tells it, a bale of barley straw fell into a scummy British pond accidentally about 10 years ago and the farmer, noticing that the algae disappeared, told agricultural researchers. "I decided to give the technique a try and to do it in a scientific way," Butler said. His efforts to replicate the process in the lab have, so far, been disappointing, he said. But he reports success using the technique this summer in six ponds, which he has been comparing with two control ponds, which remain scummy.

"One pond we're looking at here is for fire protection and that water has to be clear. It would clog everything if it were scummy," he said. "Every year, it has been treated with chemicals -- this way we may no longer have to use them."

The people who manage ponds in Columbia say they've noticed a difference with the hay bales as well. They floated some bales at Luckpenny and Dannon Garth ponds and found that algae diminished. "We did it for aesthetic reasons more than anything else," said Chick Rhodehamel, ecologist for the Columbia Association. "And it worked. The ponds look great."