Map of Operations and Maintenance Facility South project area

Operations and Maintenance Facility South project updates

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An OMF is where trains go for cleaning, storage and maintenance and operates 24 hours a day, 365 days a year. Light rail can't operate effectively in the South Sound without an additional OMF in South King County. Finding sites is challenging, as Sound Transit requires at least 30 relatively flat acres (for reference, 1 football field is 1.3 acres) that are near an operating light rail line, with specific site conditions often pushing the acreage requirement higher. 

One OMF currently exists in Seattle, and another facility is under construction in Bellevue. To accommodate additional vehicles for the future 116-mile voter-approved regional light rail system, the system requires an additional OMF in the South Sound and one in Sound Transit's North Corridor. 

What are the benefits of the OMF South?

  • Ensures thousands of passengers have clean, well-maintained trains. Trains receive cleaning and servicing between 1-5 a.m.
  • Enables nightly safety inspections of light rail tracks.
  • Employment: When the OMF South opens in 2026, it will create high-quality jobs for more than 300 people.

What can I expect as a project neighbor?

  • If you are a resident, business or property owner near an OMF South site, we encourage you to sign up for project email updates.
  • The EIS will evaluate property impacts of potential sites in detail following further design work.
  • An official decision by the Sound Transit Board about which site to select on OMF South will occur following the issue of the Final EIS in 2021.