On a weekday in the middle of spring, a crowd winds around the main terminal like confused salmon on their first spawn, searching for the end of the security line—a line that has far outgrown the stanchions and rope maze at each TSA checkpoint. Trailing roller bags with Tumi and Mickey Mouse logos, businesspeople and families search for a Sea-Tac staffer holding a tall sign that reads “End of the Line.” It’s like the worst night ever at a Trader Joe’s.

Security lines at Sea-Tac have become infamous, so much so that U.S. senator Maria Cantwell went straight to the head of the Transportation Security Administration in April to demand it open more screening lanes; at the airport’s busiest times, only about 20 of the 32 available lanes were staffed. So many passengers have missed flights that Emirates gate agents have started scouring the queues, calling out passenger names, hoping to keep customers from missing the 14-hour nonstop to Dubai.

But even if the shoes-off sideshow is tamed, Sea-Tac’s still a bustling three-ring circus. It’s the fastest growing of America’s 20 biggest airports, one that is projected to usher 66 million people a year in 2034, nearly twice its volume in 2014. Today that means 1,040 flights a day to 94 destinations; peak hours mean so few empty gates, the airport may start using hard stands, or deplaning from the tarmac onto a bus.

“With the volume that the airport is experiencing now, it is certainly slowing our ability to grow on the international front,” says Mike Medeiros, Delta Air Lines’ VP of Seattle. His airline has almost five times as many Seattle flights as it did in 2013, but they’re stymied by an International Arrivals Facility that’s in sore need of upgrades. “It was built in 1973, and not a dollar has been invested in it to improve it since then. And so it really is bursting at the seams.”

Could the answer be as simple—and gigantic—as a second airport? Picture New York City’s triumvirate of JFK, LaGuardia, and Newark, or Chicago’s twin crossroads of O’Hare and Midway. If Seattle is the new San Francisco, why don’t we have anything like the Bay Area’s trio of SFO, Oakland, and San Jose airports?

Weekday security lines at Sea-Tac. Image: Mike Kane

The idea has long been floated, and it’s finally, probably, a reality. Forget the extremely limited commercial service at Boeing Field (a few Cessnas that fly to the San Juan Islands)— developers and airlines have long been eyeing Paine Field in Everett. Designs for Paine’s terminal dropped in April, so say hello to Seattle airport number two.

Paine might be more of a Boeing field than Boeing Field—it sits next to the Boeing Everett Factory, the largest building in the world, where 747s and Dreamliners are built. There are three runways, though Boeing leases one as an airplane parking lot.

Proposals and spitball sessions about a northern Sea-Tac alternative finally gained steam by March 2015, when Snohomish County partnered with New York–based Propeller Airports to build a passenger terminal at Paine. The FAA gave the go-ahead. Low-cost carrier Allegiant expressed interest in flying to Las Vegas, and Alaska said sure, it’d consider some short hops to Portland, maybe a vacation destination or two.

“That is an airport that has great potential of serving as a secondary commercial service airport,” says Joe Sprague, senior VP of communications at Alaska Airlines. “If you’re just flying to Portland, and a lot of folks in Everett have business there, they literally might spend more time driving to Sea-Tac than they would on their flight from Sea-Tac to PDX. It’s the journey before the journey.”

So what was the holdup? Though Everett mayor Ray Stephanson has come out in support of the idea, the City of Mukilteo joined a citizen group called Save Our Communities to file suit to block it. Commercial air traffic, they argue, means pollution, unsavory businesses, and taxpayers on the hook for mitigation. In March the Ninth Circuit panel ruled against the Mukilteo contingent, and Propeller quickly announced a designer for a two-gate passenger terminal: the firm behind Denver International’s famous tent look, Fentress Architects.

Sea-Tac airport isn’t waiting for Everett to relieve its pressure. For one thing, even a handful of Paine flights wouldn’t decrease the number of transfers at the big hub; plus, Paine wouldn’t take on any of the overseas business.

Instead, Sea-Tac is in the midst of building a master plan to take Sea-Tac to the next level: The International Arrivals Facility will finally be replaced, with construction wrapping up by 2019. The airport hopes to add 35 gates to the 90 it has, plus 16 for the wide-body jets that make those long trips to Asia.

In the meanwhile, the pesky screening lines could shrink after the TSA director promised Senator Cantwell that he’d open training to more agents for Sea-Tac’s empty security lanes, and new airport director Lance Lyttle says they’re even considering moving to private security staffing rather than the TSA (which would still oversee and set standards).

Though Seattle ranks 20th nationally in size, Sea-Tac is the 13th busiest air hub. It’ll always be our gateway, but it’s about to have company. “As far as I’m concerned, it’s a certainty,” says Propeller Airports CEO Brett Smith about the imminent Everett flights. “It’s not like 10 years from now. We’re looking to start service next year.”