Drunk Air Traffic Controller Under Investigation. Veteran controller tested for drugs and alcohol while working on job.

The Federal Aviation Administration is investigating an air traffic controller for allegedly working while drunk at an air traffic center in Longmont, Colorado, an FAA official confirms to CBS News.

The unidentified controller, reportedly a veteran and former union rep, was around midway through his shift July 5 when he failed a random drug and alcohol test administered onsite. The blood alcohol limit is 0.02 for ATC employees - one quarter as much as the 0.08 limit for driving in most states- but the FAA would not disclose specifics as the the controller's blood alcohol level.

"The controller in question is not working air traffic. We are investigating the incident," said the official, who spoke on condition of anonymity.

The head of the National Air Traffic Controllers Association called the incident "deeply troubling."

"We take our responsibility of ensuring aviation safety very seriously. That includes acting professionally in all that we do. Thus, this incident is deeply troubling. We do not condone the alleged conduct at Denver Center currently under investigation. We are proud of our safety record both there and at every facility and will continue to work to keep our airspace system the world's safest," Paul Rinaldi, president of the NATCA, said in a statement.

If the allegations against him are true, it's just the latest in a string of disturbing incidents.

Earlier this year, at least nine controllers were investigated for various transgressions. Among them:

Feb. 19 - a controller was found intentionally sleeping in the radar room in Knoxville, Tenn., forcing colleagues to assume his duties. That offender has since been fired.

March 23 - a controller at Reagan National Airport in Washington, D.C., is suspended for failure to respond to two incoming planes. The 20-year veteran working on four consecutive overnight shifts told investigators he inadvertently fell asleep.

April 11 - the controller at Seattle's Boeing field was terminated after twice falling asleep on duty. The next day a controller found sleeping in the tower at Reno-Tahoe International Airport while a medical flight tried to reach him. Eventually a regional controller stepped in to guide the traffic.

According to ABC affiliate KMGH, which first reported the story, the Colorado controller's family has said he's undergoing alcohol addiction treatment, and has been told by the FAA he may be reemployed, at some level, once that treatment is complete.

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