As Sound Transit moves closer to building the 7.8-mile-long Federal Way Link Extension light rail project, the selection of Kiewit Infrastructure West Company to design and build the project marks a major milestone. 

Kiewit will construct the extension from the Angle Lake station in SeaTac to Federal Way, building three new stations along the way. The total amount of the contract, with contingency funding, comes in at $1.4 billion.

“The addition of light rail to Federal Way will give South King County residents a much-needed transit option,” Pete von Reichbauer, King County Council member and Sound Transit board member, said in a statement. “The Federal Way Link Extension is a long-awaited addition to our region that encourages employers to look beyond the downtown Seattle area and will transform the way we travel for work and leisure activities.”

The design-build contract includes all work to complete final design and construction of the light rail guideway, which will connect to the existing Angle Lake station in SeaTac and extend south along the west side of I-5 to the Federal Way Transit Center. Kiewit will also complete final design and construction of three new light rail stations, three parking garages, the overhead catenary system, traction power substations, train control and communications, special track work, utilities and street improvements. 

Sound Transit is collaborating with the Washington State Dept. of Transportation on the State Route 509 Completion Project, and as part of the agreement Kiewit will build a new bridge over SR 99 near 208^thStreet in the City of SeaTac as part of the first stage of the SR 509 project. Sound Transit says that the joint effort on two projects happening in the same area will reduce impacts to the community. 

Kiewit expects to start early demolition and utility relocation work later this year with major civil construction expected to begin in 2020. Service on the new regional light rail extension is scheduled for 2024. 

The Federal Way project was recently approved to advance to the engineering phase, a necessary step toward securing a grant from the Federal Transit Administration’s Capital Investment Grant program, while earning a “Medium-High” rating by the federal reviewers, one of the highest marks in the country. By moving the project into the engineering phase, the FTA locked in the grant funding amount at $790 million, the level requested by Sound Transit.

The project is in line for the final of four loans from the Transportation Infrastructure Finance and Innovation Act. Sound Transit becomes the first transportation agency in the country to enter into a master credit agreement with the U.S. Dept. of Transportation that will provide $2 billion in low-interest loans spanning four projects. The loans, enabled by the USDOT’s Build America Bureau TIFIA, are cumulatively forecasted so save regional taxpayers between $200 million and $300 million through lower interest costs. 

“This is the next step to extend Link light rail to the heart of South King County and position us to continue onward to Tacoma,” said John Marchione, Sound Transit Board chair and Redmond mayor, in a statement. “Light rail will offer congestion-free travel in the South Sound across a regional system that will eventually extend 116 miles.” 

As Sound Transit continues its plan to form a 116-mile regional system by 2041 as the fastest-growing transit agency in the country, the next scheduled extension opening is Northgate Link in 2021, followed by East Link in 2023. Additional extensions to Shoreline, Mountlake Terrace, Lynnwood, Ken/Des Moines, Federal Way and downtown Redmond are planned in 2024. Further light rail extensions will reach West Seattle, Fife and Tacoma in 2030, Ballard in 2035, Paine Field and Everett in 2036 and South Kirkland and Issaquah in 2041. 

Follow Tim Newcomb on Twitter at @tdnewcomb.