BALTIMORE (WJZ) — Keep the change. That’s exactly what the Transportation Security Administration does when you leave loose change at airport security checkpoints–and that change really adds up.

Marcus Washington with a look at where that money goes.

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It’s the line of uncertainty: Will it move fast or slow? Will I get through in time to catch my flight?

“Now that it’s summer time, it’s a heavy travel season. But not only a heavy travel season, it’s a heavy travel season for people who don’t tend to travel frequently,” said Lisa Farbstein, TSA.

A TSA checkpoint leaves challenges for some travelers. Many of those travelers leave something behind.

In 2014, more than $675,000 in loose change was left behind at TSA checkpoints by travelers throughout the U.S.

In our area, nearly $8,500 was left behind at BWI Thurgood Marshall. Reagan National? Try more than $9,500. And at Dulles? More than $22,000 in loose change left behind at checkpoints.

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Washington: “What do you do with all of that money?”

Farbstein: “So what happens is that in 2005 Congress gave TSA permission to use all of that money that is left behind at checkpoints for security operations. And that’s exactly how we use it.”

For some of the 20,000-plus travelers who pass through BWI TSA checkpoints, the amount of money is shocking.

“Yeah, it’s pretty surprising. I leave quite a bit in my couch, but not that much,” said one traveler.

“That’s pretty crazy to me. That’s a lot of money,” another traveler said.

So what do you do to prevent adding to the growing amount of loose change?

“You’re less likely to leave it behind if you put it into your carry-on bag,” said Farbstein.

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The top three airports with the largest amounts of loose change collected are San Francisco, Los Angeles and JFK.