Contractors will begin laying concrete for Sea-Tac Airport’s 8,500-foot third runway beginning in mid-July.
That date is about three weeks later than orginally planned, but the delay isn’t expected to materially affect the runway’s opening date, now scheduled for November next year.
The runway project from conception to completion will have taken some 15 years by the time the first plane lands on it next year.
A coalition of cities and neighborhood organizations challenged the runway project repeatedly in court, and the runway’s actual construction has taken more than three years.
The paving will require some 133,000 cubic yards of concrete and 35,000 tons of asphalt. The runway concrete will be about 17 inches thick to withstand the pounding it will receive from planes landing at high speed.
The most difficult and sensitive part of the project is now behind the contractors. That phase required acquisition and demolition of homes on the airport’s west side and cleanup and rerouting of several creeks in the area. Bringing the land surface up to the level of the airport’s other two runways required thousands of dump truck loads of soil to be brought from off-site areas and the construction of huge retaining wall to keep the soil in place.
At last report, the runway’s construction and associated environmental mitigation activities was budgeted at $1.2 billion.