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Operations and Maintenance Facility South

The comment period for the NEPA Draft /SEPA Supplemental Draft Environmental Impact Statement closed on November 6, 2023. The Final EIS, which will include responses to substantive Draft EIS comments and evaluation of the preferred and other alternatives, is anticipated to be issued in mid-2024. After that, the Sound Transit Board will select a project to be built in mid to late 2024, and the Federal Transit Administration is anticipated to issue a Record of Decision under NEPA.

Welcome

What's the latest?

We published a Draft EIS under the State Environmental Policy Act in 2021 that evaluated three possible sites for the OMF South facility. After a public comment period (engagement summary, comment summary), the Sound Transit Board identified the South 336th Street site in Federal Way as the preferred alternative in December 2021. To align federal and state processes, we are now publishing a National Environmental Policy Act Draft/SEPA Supplemental Draft EIS (Draft EIS) that evaluates these same alternatives. Based on its transit expertise and greater federal funding opportunities, the Federal Transit Administration will be the lead federal agency. A joint NEPA/SEPA Final EIS will follow in 2024.

  • All public comments provided on the SEPA Draft EIS in 2021 are valid and do not need to be resubmitted.
  • We will respond to all substantive comments from both comment periods in the Final EIS.
  • After the Final EIS is published, the Sound Transit Board will select the project to be built.

Sound Transit is working toward an opening in 2032 but is also pursuing measures to advance the opening earlier (potentially 2030). If the Midway Landfill alternative is selected as the project to be built, the opening date would be between 2035 and 2037 depending on the subsurface construction design option. We will share an updated project schedule when we have more certainty.

What has changed since the SEPA Draft EIS was published in 2021?

We’ve continued the project’s design and engineering work since the 2021 publication of the SEPA Draft EIS. We’ve evaluated the potential environmental impacts of several design refinements, in the Draft EIS which include:

  • The addition of a test track and associated access road to the proposed site layouts for South 336th Street preferred alternative and South 344th Street alternatives. The test track would help us prepare new and existing light rail vehicles for service. The Midway Landfill alternative would not include a test track.
  • Updates to the South 336th Street preferred alternative site layout in close coordination with the City of Federal Way.
    • The main site entrance has been moved from SR 99 to South 340th Street.
    • 18th Place South has been extended to replace the functionality of 20th Avenue South. The 18th Place South extension would also include a multi-use path.
    • The site has been expanded to the southwest to accommodate the 18th Place South extension and to provide more yard area space.
    • 21st Avenue South has been extended to connect to South 344th Street.
    • Road widening has been incorporated on the south side of South 336th Street to meet city requirements.
    • Existing culverts that convey the West Fork Hylebos Creek Tributary under South 336th Street and the East Fork Hylebos Creek Tributary under South 344th Street are planned to be removed and replaced with fish passable structures.
    • The site and internal track configuration has been modified to allow for a wider stream and wetland corridor on the east side of the OMF, between the site and I-5.

An OMF is where Link light rail trains go for cleaning, storage, and maintenance, 24 hours a day, 365 days a year. Sound Transit needs four strategically located OMF facilities. We need this new OMF in the South Sound to receive, store, and service a larger train fleet to support future light rail extensions to Tacoma and throughout the region. To build this new facility, we need approximately 60-70 acres (for reference, one football field is 1.3 acres) near the Federal Way Link Extension.


November 2016: Voter approval

Voters approved 118 miles of Link light rail, including two new OMFs—one in the north corridor and another in the South Sound—to serve the growing light rail system.

Mid to late 2018: Initial community idea gathering and evaluation

After receiving community input during the early scoping outreach period in April 2018, Sound Transit identified 24 potential OMF South sites for further analysis. After initial screening, we reduced the number of potential sites to 20. We assessed these 20 sites with a robust list of evaluation criteria, including project schedule, long-term facility planning, operational requirements, environmental impacts, and engineering risks, among others.

February to April 2019: SEPA Scoping

Based on the results of the detailed screening, Sound Transit recommended six sites in Kent and Federal Way for further consideration. The public had the opportunity to share their thoughts on the six potential sites, as well as the OMF South project Purpose and Need Statement and environmental resources to evaluate in the Draft Environmental Impact Statement, during the scoping comment period under the State Environmental Policy Act.

May 2019: Sound Transit Board action

After reviewing community feedback gathered during scoping and the thorough evaluation on the the six potential sites, the Sound Transit Board identified three sites for further study in the Draft EIS:

  • Midway Landfill alternative
  • South 336th Street alternative
  • South 344th Street alternative

Summer 2019 to 2021: SEPA Draft EIS

Sound Transit prepared a Draft EIS under SEPA to share findings with tribes, agency and jurisdictional partners, social service and cultural organizations, and the public. We published the SEPA Draft EIS in 2021 and held a public comment period (engagement summary, comment summary).

December 2021: Sound Transit Board identified a preferred alternative

After the SEPA Draft EIS comment period, the Sound Transit Board considered the SEPA Draft EIS analysis and comments received and then identified the South 336th Street site in Federal Way as the preferred alternative, with all three sites still to be evaluated in a Final EIS.

December 2021 to July 2023: Project refinements

After the Sound Transit Board identified the South 336th Street site in Federal Way as the preferred alternative, we completed additional fieldwork activities and environmental analysis. Additional site refinements were made to the preferred and South 334th Street alternatives.

July to August 2023: NEPA Scoping

After the Federal Transit Administration became the lead agency for the OMF South project, both the Federal Transit Administration and Sound Transit held a scoping comment period under NEPA for comments in addition to those received during SEPA scoping.

We are here: Draft EIS

To align the federal and state processes, the Federal Transit Administration (FTA) and Sound Transit have published a NEPA Draft/SEPA Supplemental Draft EIS that evaluates the same three alternatives as the 2021 SEPA Draft EIS. FTA is the lead agency under NEPA and Sound Transit is the lead agency under SEPA. This additional review is to support federal approvals, federal funding and assess project design changes. The findings from the EIS are being shared with Tribes, agency and jurisdictional partners, and the public through a 45-day public comment period. All public comments provided on the SEPA Draft EIS in 2021 remain valid and do not need to be resubmitted. After receiving and considering public comments, FTA and Sound Transit will complete a joint Final EIS before the Sound Transit Board selects the project to be built.


Aerial view of the existing operations and maintenance facility in Seattle. This facility receives, stores and services Sound Transit’s Link light rail trains. The site includes a Link train storage building, offices for operations and controls, and a yard with Link trains lined up on tracks.

We service our current light rail trains at a central OMF on South Forest Street in Seattle

The benefits of OMF South

  • Creates high-skilled, living-wage jobs for more than 610 people in South King County. At our existing OMF, the average employee wage is more than $40 per hour, or $80,000/year.
  • Ensures thousands of passengers can rely on clean, well-maintained trains.
A worker performs maintenance on a Link light rail train at the operations and maintenance facility in Seattle. The worker is inside the train making a repair to the overhead lighting with a screwdriver.

 

 

Environmental review

What is an Environmental Impact Statement?

Before Sound Transit builds projects, we study the potential effects each project alternative may have on the natural and built environment in a document called an Environmental Impact Statement. The EIS helps decision makers, the public and our project partners evaluate the possible environmental impacts of each potential site during construction and operation. The EIS also compares the effects of each alternative to inform the public, agencies, and the Sound Transit Board.

In the OMF South Draft EIS, we looked at how the Midway Landfill, South 344th Street, and South 336th Street alternatives would affect air and water quality, historical and cultural resources, property acquisition and land use, economic effects, hazardous materials, ecosystem resources, cost, schedule, and more. In December 2021, the Sound Transit Board identified the South 336th Street alternative as the preferred alternative.

Now, we’re combining our state (SEPA) and federal (NEPA) environmental review processes. We’ve published a Draft EIS that evaluates these same alternatives. A Final EIS will follow in 2024.

What potential environmental effects are different from the 2021 SEPA Draft EIS?

Since the 2021 SEPA Draft EIS, we've updated the analysis for all three alternatives. Here are some key updates.

Increased residential displacements for Federal Way sites (preferred alternative and South 344th Street)

Other notable changes to potential effects from the preferred alternative

Other notable potential effects

Why should I comment on the Draft EIS?

All comments that were provided on the SEPA Draft EIS in 2021 remain valid and do not need to be resubmitted. We will respond to all substantive comments from both comment periods in the Final EIS.

During this Draft EIS comment period through Nov. 6, you can provide feedback on the alternatives, EIS analysis, and summary of scoping comments. SEPA Draft EIS comments from 2021 remain valid and do not need to be resubmitted; however, if you’d like to comment again, focus your comments on the project changes and updated analysis. After the comment period, we’ll then prepare a Final EIS, which will evaluate the preferred and other alternatives, and include responses to all substantive comments received on the Draft EIS. We expect to publish the Final EIS in 2024, then the Board will select the project to be built. Why comment? Comments from Tribes, the public, and agency partners inform the Board in their decision-making.

Did you receive a property owner letter or think the project may affect your property? A notification of potential impact does not mean a decision has been made to purchase your property, but it does mean there’s a possibility we would need to acquire your property in the future.

Final decisions on affected properties and acquisitions generally won’t occur until after the Final EIS and the Sound Transit Board selects the project to be built. In some limited cases, Sound Transit purchases properties prior to the Board's action. If we determine that your property is needed for OMF South, Sound Transit will initiate official conversations around acquisitions and relocation at that time and after an independent appraisal process.

Our project outreach team is available to help with questions every step of the way. To set up a property owner briefing with members of the project team you can:


 

Alternatives

This section of the online open house provides key features about each of the three alternatives. This information is also provided in the Draft EIS. Learn more about how each of the alternatives could affect air and water quality, historical and cultural resources, nearby properties, ecosystem resources, cost, schedule, and more. Scroll through this section to learn key features for all alternatives and view key impacts in the next section of this website. Then, comment to share your thoughts on our findings.

You can also explore this information as a downloadable PDF (available in English, Korean, Spanish, and Russian), in the Draft EIS Executive Summary (English), and in the Draft EIS (English). These documents are accessible for screen readers. Please contact us at OMFSouth@soundtransit.org or 206-398-5453 for additional accessibility resources.

The Draft EIS is available for public review in a variety of formats and locations.

 

Preferred alternative (South 336th Street)

On Dec. 16, 2021, the Sound Transit Board identified the South 336th Street alternative in Federal Way as the preferred alternative for OMF South.

Key features

  • The preferred alternative is in Federal Way, between South 336th Street and South 341st Place, and between I-5 and SR 99.
  • The site footprint is approximately 66 acres.
  • The preferred alternative includes about 1.4 miles of mainline light rail tracks🛈 . These tracks would also be needed for the Tacoma Dome Link Extension light rail alignment.
  • The preferred alternative also includes a test track to prepare new vehicles for service. The test track would run parallel and on the east side of the connecting light rail tracks.

We would need to construct 1.4-1.8 miles of additional track (also called “mainline” track) between the end of the Federal Way Link Extension (currently in construction) to the potential OMF sites in Federal Way—the preferred alternative at South 336th Street and the South 344th Street alternative—to transport light rail cars from the regional system to the OMF South. We’re also studying this track in the environmental review for the Tacoma Dome Link Extension as part of the route.

If the Midway Landfill alternative is selected as the project to be built, these tracks in Federal Way would be built as part of TDLE.

The Midway Landfill site is next to the Federal Way Link Extension route, so aside from short connecting tracks to the facility (also called “lead” tracks), there would be no added light rail track needed for that alternative.


Before a new light rail vehicle can start carrying passengers, we need to test how it performs on the track. Since we have light rail service running on the mainline track during most of the day, we currently do all vehicle testing during the short service window from 1-5 a.m. Building a test track will allow us to test vehicles more quickly to get them ready for service—and we have a lot more cars coming online as we expand the regional light rail system! After analyzing the most suitable location for a test track in our system, we found that siting it near OMF South was the best fit technically and operationally.

A map of test track and access road associated with the preferred and South 344th Street alternatives in Federal Way.
A test track would run parallel to the connecting light rail tracks for the preferred alternative and South 344th Street alternative. | Click to enlarge

South 344th Street alternative

Key features

  • The South 344th Street alternative is in Federal Way, between South 336th Street and South 344th Street, and between I-5 and 18th Place South.
  • The site footprint is approximately 64 acres.
  • The South 344th Street alternative includes about 1.8 miles of mainline light rail tracks🛈 . The tracks would also be needed for TDLE.
  • This site would include a test track. The test track would run parallel and on the east side of the connecting light rail tracks.

We would need to construct 1.4-1.8 miles of additional track (also called “mainline” track) between the end of the Federal Way Link Extension (currently in construction) to the potential OMF sites in Federal Way—the preferred alternative at South 336th Street and the South 344th Street alternative—to transport light rail cars from the regional system to the OMF South. We’re also studying this track in the environmental review for the Tacoma Dome Link Extension as part of the route.

If the Midway Landfill alternative is selected as the project to be built, these tracks in Federal Way will be built as part of TDLE.

The Midway Landfill site is next to the Federal Way Link Extension route, so aside from short connecting tracks to the facility (also called “lead” tracks), there would be no added light rail track needed for that alternative.


Before a new light rail vehicle can start carrying passengers, we need to test how it performs on the track. Since we have light rail service running on the mainline track during most of the day, we currently do all vehicle testing during the short service window from 1-5 a.m. Building a test track will allow us to test vehicles more quickly to get them ready for service—and we have a lot more cars coming online as we expand the regional light rail system! After analyzing the most suitable location for a test track in our system, we found that siting it near the OMF South was the best fit technically and operationally.

A test track would run parallel to the connecting light rail tracks for the preferred alternative and South 344th Street alternative.
A test track would run parallel to the connecting light rail tracks for the preferred alternative and South 344th Street alternative. | Click to enlarge

Midway Landfill alternative

Key features

  • The Midway Landfill alternative is in Kent, between South 246th Street and South 252nd Street, and between I-5 and SR 99.
  • The site footprint is approximately 68 acres.
  • Due to its location along the Federal Way Link Extension line, the Midway Landfill does not include mainline connecting tracks.
  • This site would not include a because of varying grades. A test track needs to be primarily at-grade and on relatively straight and flat terrain, making this location not suitable for meeting minimum operational and construction requirements.

Building on top of a landfill is a unique and complex challenge. Sound Transit must address the likelihood that this ground will continue shifting and settling over time, which could affect the tracks, equipment and other infrastructure. To prevent settlement, Sound Transit is considering three methods to prepare the Midway Landfill site for possible OMF construction: Platform, Hybrid, and Full Excavation. Due to contaminated material, material removed from the Midway Landfill during construction would require disposal at another landfill facility equipped to accept contaminated waste. The material would be hauled by truck to a regional transfer facility and sent on by rail for disposal.

Platform

Construct an approximately 3.5-foot thick, 35-acre concrete platform on top of a new landfill cap to support the facility. The platform option would require removing some of the landfill and drilling approximately 700 concrete support shafts roughly 120-180 feet deep.

Graphic illustrating the Midway Landfill Platform construction method.
Click to enlarge

Hybrid

Excavate almost all the landfill and replace it with soil and a 1-foot thick, 30-acre concrete slab supported by beams to provide a new surface to build the OMF. The Hybrid option would also require approximately 300 drilled concrete support shafts roughly 140 feet deep.

Graphic illustrating the Midway Landfill Hybrid construction method.
Click to enlarge

Full Excavation

Remove and dispose of virtually all the landfill material and backfill with new soil. The Full Excavation option would not include concrete support shafts.

Graphic illustrating the Midway Landfill Full Excavation construction method.
Click to enlarge

These three site preparation options have different impacts, which is why you’ll sometimes see three different values listed for the Midway Landfill site in the next section.


Key impacts

Because of the need for the mainline track, the environmental impacts for the preferred and South 344th Street alternatives are shown as two numbers, representing the impacts for the site and the mainline tracks.

Midway Landfill construction opotions

*Estimates are to be used for comparisons between alternatives only and do not represent the project budget. The preferred alternative and South 344th Street alternative estimates are for the sites only and do not include costs for mainline tracks.

** These track impacts in Federal Way would occur as part of TDLE if the Midway Landfill alternative were selected as the project to be built.

¹Includes GarageTown, comprised of ~60 owners.

**These track impacts in Federal Way would occur as part of TDLE if the Midway Landfill alternative were selected as the project to be built. 

Next steps

What comes next for OMF South

After the NEPA Draft/SEPA Supplemental Draft EIS comment period closes on Nov. 6, 2023, comments will be compiled and evaluated, and a summary of your comments will be provided to the Sound Transit Board. Comments will be made available to the public at that time. The Final EIS, which will include responses to substantive Draft EIS comments and evaluation of the preferred and other alternatives, is anticipated to be issued. After that, the Board will select a project to be built in mid to late 2024, and the Federal Transit Administration is anticipated to issue a Record of Decision under NEPA.

OMF South schedule*

Sept. 22 to Nov. 6 2023

  • Draft EIS comment period

Mid-2024

  • Final EIS published

Mid to late 2024

  • Sound Transit Board selects the project to be built and FTA issues Record of Decision

TBD

  • Design and construction

2032**

  • Open for operations

*Subject to change.

**Sound Transit is pursuing measures to advance the opening earlier (potentially 2030). If the Midway Landfill alternative is selected as the project to be built, the opening date would be between 2035 and 2037 depending on the subsurface construction design option.

Link light rail trains are staged on maintenance platforms in the Link Storage Building. Stairs are provided on the platform so that workers can access both the top of the train and the underside of the train to perform routine maintenance.

Link light rail trains are parked on maintenance platforms in the Link Storage Building.