Prince George's County Health department inspectors have found no hazardous or toxic materials stored at three sites named in a congressional report as repositories for potentially dangerous wastes.

"We had crews out to all three sites," said John Koontz, director of environmental engineering for the health department. "We didn't find anything dangerous, beyond some trash that really should have been moved."

The sites were named in a report, issued last October by the House Commerce subcommittee, which identified 3,383 potentially hazardous waste disposal sites nationwide. The report was not forwarded to local officials however, and Koontz did not launch his investigation until after he was told about it by a reporter two weeks ago.

The report urged the U.S. Environmental Protection Agency to develop its own list and to work toward mitigating any dangers that might be associated with the improper storage of hazardous chemicals.

Koontz, in reviewing the EPA list of Hazardous waste sites, said he was concerned about a Montgomery County, listing -- the Army's Harry Diamond Laboratories.

The facility, which straddles the Montgomery-Prince George's county line near Adelphi, is an electronic microcircuitry and research laboratory that handle copper, iron and silver in "considerable quantities," according to a public information spokesman. Other materials handled at the facility include arsenic, cadmium, chromium, cyanide, lead and nickle.

H. Stevens Kemmel, public information officer for the laboratory, said there are no radiological, or radioactive, materials on the grounds.

"We're clean. And if we're not, we want to be," Kimmel said.

The facility was charged with illegally dumping oil and chemicals into the northwest branch of Paint Branch Creek about six years ago, said Eric Mendelsohn, chief of air and noise control at the Montgomery County Environmental Protection Department.

"Recently, we haven't heard about any problems there," he said.

The Army lab does not need an operating permit from the Maryland Department of Natural Resources to handle hazardous substances because it does not store wastes for more than 90 days, stores it in the interim in approved containers, and does not dispose of wastes on the premises. The facility does have a permit to transport waste elsewhere.