Federal prosecutors allege a gold and silver refining plant has been discharging excessively high amounts of selenium into the Jordan River and Great Salt Lake and concealing its illegal activities.

A 29-count indictment was returned late Wednesday citing numerous charges against Johnson Matthey Inc., an international conglomerate with a local plant at 4601 W. 2100 South, West Valley City.

Also named were two men, John David McKelvie, director of gold and silver operations for North America and Europe, and Paul Card Greaves, a former plant manager.

Prosecutors say the firm and the two men allowed illegally high amounts of selenium to be discharged into local waters and conspired to hide what they had done.

"These allegations are disturbing, and we take them very seriously as we do any illegal behaviors that would undermine the enforcement of our environmental laws," Justice Department spokeswoman Cynthia J. Magnuson said.

Lengthy exposure to selenium can hurt humans by damaging tissue in the kidneys and liver, as well as harming the nervous and circulatory systems. High levels of the chemical also are harmful to various kinds of birds and can cause reproductive problems and deformities in their offspring.

The Jordan River and the Great Salt Lake are part of a shorebird reserve, a temporary home to millions of migratory birds each year.

If the men are convicted, each count carries a maximum penalty of five years in prison and a $250,000 fine. The corporate fine, if a conviction occurs, would be $500,000 on each count.

Lynn de Freitas, executive director of the conservation group Friends of Great Salt Lake, was concerned about whether these allegations involve an isolated situation or whether other industries might be engaging in illegal activities. "That's something that should trouble all of us," de Freitas said.

Robert M. Talley, a vice president for Johnson Matthey, said in a written statement that the firm has cooperated fully in the federal investigation and has conducted its own investigation.

"Johnson Matthey will continue to cooperate and work with the Department of Justice and EPA in an effort to resolve these charges and is prepared to defend against them in Salt Lake City federal court, if necessary," Talley said.

Talley said the firm "has invested millions of dollars in environmental control equipment at the Salt Lake refinery."