MIAMI — The Port of Seattle Commission approved new airport expansion and improvement projects worth nearly $1 billion for Seattle-Tacoma International Airport (SEA) earlier this week.

The projects include the construction of a new international arrivals complex, reconstructing the center runway, updating both satellite terminals, and building a bridge between the south satellite and the new arrivals facility.  Work starts in the fall of 2015, with completion expected in the summer of 2019.  The airport’s airline tenants will pay the costs.  Serving 37 million passengers per year, SEA is the 15th busiest airport in the U.S., and it has recently become a battleground between Alaska and Delta.

With the north satellite redesign, Alaska’s operations will get eight new gates for a total of 20 and bring the interior design to 21st Century standards, including a new lounge for Alaska’s frequent fliers.  Alaska, which has over 50 percent of SEA’s market share, will have its combined flights ultimately served by the north satellite and Concourse C.

The south satellite terminal, where Delta has been rapidly growing a West Coast international hub, will get an updated interior to include new carpets, new podiums, updated signage, and repainting.  A new bridge will allow international passengers to move from the south satellite to customs and immigration facilities at the new international arrivals facility.  Both satellite terminals will continue to operate normally during the expansion.

The new international arrivals complex will allow international passengers to arrive at the south satellite, as they currently do, and it will also allow them to arrive at Concourse A.  This is important given the overall rapid growth in international flights currently arriving at SEA, which cause passenger overcrowding in the current 1970’s era facility during the peak hours.