6:55 p.m. Update: Farbstein wrote by e-mail that she’s “excited about the opportunity to focus on the challenges facing national transportation security.”

Original post: Lisa Farbstein, the longtime director of media relations at Metro, is leaving to join the Transportation Security Administration.

Farbstein’s departure comes as General Manager Richard Sarles makes overall changes in the communications department at the transit authority. The Washington Examiner first reported Farbstein’s departure.

Farbstein’s position is being taken over in part by Dan Stessel, who is director of communications for the New Jersey Transit system, which Sarles headed until he retired in January 2010. Stessel will help oversee the day-to-day media relations shop and will work to enhance the agency’s social media activities, a Metro official said.

Stessel posted the news in the biographical section of his Twitter account, where he wrote, “Until May 20: Senior Director, Corporate Communications at New Jersey Transit ... As of May 23: Chief Spokesperson/Dir. Communications at WMATA.”

“It's a very exciting opportunity to be joining this team at Metro,” Stessel told The Washington Post.

Stessel, 35, said he lived in the D.C. area when he was a student at George Washington University and later resided in the Arlington and Alexandria areas for 10 years. He previously worked at Amtrak as manager for media relations for the Northeast Corridor.

“I remember Metro from the ’90s,” he said. “I know what a world-class transportation system it is. There’s work to be done to make the system more reliable. We’re committed to doing even more to bring it back to a state of good repair. It is gratifying to be a part of that.”

A Metro official said Stessel was selected from a pool of 80 candidates by a three-member panel. Since taking the reins as temporary chief last year, Sarles has brought in new Metro managers from his days at NJ Transit and Amtrak. (Sarles was named to the permanent job in January 2011.)

A Metro spokeswoman said Farbstein is leaving Metro for the TSA, where she will work in the agency’s communications department, representing the New York and New Jersey regions. Farbstein, who began a two-week vacation last week, did not respond immediately to a message left on her cellphone voice mail or to an e-mail.

Sarles begin making changes in the communications team last year. He hired Barbara Richardson, who he worked with at Amtrak, as assistant general manager of customer service, communications and marketing. Last fall he brought in Lynn Bowersox to work as Metro’s managing director of public relations. She had worked at NJ Transit as assistant executive director for communications.

  Personnel in the media relations department will report to Stessel, who will report to Bowersox. Bowersox reports to Richardson; and Richardson reports directly to Sarles.