Traces of a bacteria possibly related to Legionnaires' disease were found in the cooling system at a Northeast Washington postal facility more than a month after the disease was diagnosed in a man who works there, a Postal Service spokeswoman said yesterday.

The quantity found was "very minuscule" and poses no danger to the 1,000 employees who work at the Curseen-Morris facility, said Deborah Yackley, the Postal Service spokeswoman. "We are not recommending that they leave; it is perfectly safe," she said.

The Postal Service ordered the tests after an employee contracted the disease in July. The sometimes fatal lung infection is often caused by inhalation of bacteria from air conditioning. The disease has not been diagnosed in any other employees, she said.

Of 93 test samples, the Postal Service found "Legionella-like bacteria" in three of the samples, Yackley said. In one sample, the level of bacteria was higher than what the Occupational Safety and Health Administration deems acceptable, she said.

The samples were sent for further testing, Yackley said, and the air conditioning system where the bacteria were found has been taken apart and disinfected.

The Curseen-Morris plant is where two workers died from anthrax contamination four years ago. Postal employees learned of the Legionnaires' test results Monday night and yesterday.

Joe Henry, a union leader representing letter carriers at the facility, said he believes the Postal Service is aggressively moving to ensure that workers are safe. Describing his members' response, he said, "While they're concerned, they're okay."

Gregg A. Pane, director of the District's Health Department, said his agency is monitoring testing.