The Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTP) environmental review schedule is delayed as a result of the COVID-19 pandemic. The delay is intended to provide the ability to host effective and safe public meetings, and includes a partial deferral of spending in 2020. The release of the first environmental review analysis, the draft NEPA Environmental Assessment (EA), and the accompanying public outreach, will now occur in the first quarter of 2021. The Port continues to refine the detailed schedule.

The master plan is a necessary step forward for the future of Seattle-Tacoma International Airport (SEA). The Port continues work to complete the environmental review of the SAMP NTP. Once the environmental review is complete, which is expected in 2021, Commission authorization is required to initiate any individual project.

See updated schedule below.




The Port of Seattle and FAA is conducting an environmental review of the SAMP Near-Term Projects.

Forecast and schedule update.

As part of the environmental review process for the SAMP Near-Term Projects (NTP), the Port of Seattle reviewed the original aviation forecasts prepared for the SAMP to understand if the projections of future activity remain valid. Based on yearly activity data since 2015, actual growth is exceeding forecasted growth in a notable way. As a result, the Port of Seattle undertook a forecast update to better reflect the stronger growth being observed. The forecast update was unconstrained, meaning that it projected growth solely based on market demand for air travel to/from Seattle, not considering other constraints on activity. Further analysis of the updated projected growth, and the resulting levels of delay, indicated that without constructing new facilities, the airport would likely experience significant reductions in the rate of growth after 2023. When growth rates are reduced due to delay resulting from a lack of facilities, it is referred to as a constrained operating environment.

The Port of Seattle took these factors into account when developing the level of operations and passengers for the SAMP environmental review. The table below shows the unconstrained forecasted operations and passengers from the most recent update, compared to the constrained level of operations and passengers that will be used in the SAMP NTP environmental review.



SAMP Demand Forecast and Constrained Scenarios

Extended Schedules


The Port of Seattle and FAA is conducting an environmental review of the SAMP Near-Term Projects.

In December 2019 the environmental review period was extended to incorporate feedback heard during the environmental scoping period. Environmental review will include additional topics that the public raised during the scoping period, update the 2014 demand forecast to reflect the rapid growth that occurred in the last few years, and complete the NEPA and SEPA analysis separately and sequentially.


Thanks to all who completed agency and public comment submittals during the scoping for the SAMP Near-Term Projects, which closed on September 28, 2018. The Federal Aviation Administration (FAA) and the Port of Seattle take each comment very seriously and appreciate the efforts each agency and individual took to participate.


The FAA initiated a National Environmental Policy Act (NEPA) Environmental Assessment (EA) and the Port of Seattle (Port) initiated a State Environmental Policy Act (SEPA) Environmental Impact Statement (EIS) to evaluate and disclose the potential environmental effects of the Near-Term Projects.

Comments received during scoping were reviewed and will be taken into consideration during the environmental analyses. The Port of Seattle and its consultant, in conjunction with the FAA, are currently conducting the environmental analyses.
The FAA and Port will issue two separate documents, with the FAA’s NEPA EA coming first and subsequent environmental decision; followed by the Port’s SEPA EIS. There will be an agency and public review and comment period for both documents.

As the Port and FAA go through the environmental analyses and better understand the timing of the draft environmental documents, the Port will provide updates on timing and next steps on this website.