COMMISSION AGENDA MEMORANDUM BRIEFING ITEM Item No. Date of Meeting 11b May 26, 2026 DATE: May 8, 2026 TO: Stephen P. Metruck, Executive Director FROM: Sarah Cox, Director, Aviation Environment and Sustainability Steve Rybolt, Senior Environmental Program Manager, Aviation Environment and Sustainability SUBJECT: Sustainable Airport Master Plan Near-Term Projects Environmental Review - SEPA Draft Environmental Impact Statement and Public Comment Period EXECUTIVE SUMMARY This briefing will provide an overview of the State Environmental Policy Act (SEPA) Draft Environmental Impact Statement (DEIS) findings for the SAMP NTPs that will be published on May 22, 2026. This will include a summary of the rigorous and thorough analysis that was completed for the sixteen SEPA elements of the environment categories that are required to be evaluated by the Port's SEPA Policy (Commission Resolution No. 3650) and State of Washington's SEPA provisions (Washington Administrative Code [WAC] 197-11). It will also provide an overview of the outreach and engagement plan for the 60-day public comment period that will occur between May 22, 2026, to July 21, 2026. It is anticipated that SEPA will be completed by the end of 2026. DETAILS The Port of Seattle has completed the SEPA DEIS of the SAMP NTPs. The SEPA DEIS built upon the rigorous Environmental Assessment (EA) that was completed by the Federal Aviation Administration (FAA) under the National Environmental Policy Act (NEPA). The purpose of SEPA and this DEIS is to assess if the NTPs have the potential to result in impacts to sixteen different SEPA element of the environment resource categories. When impacts were identified, the analysis evaluates the extent of those impacts, and if required, identified ways to reduce, avoid, or mitigate them. The following SEPA elements of the environment categories were evaluated: Template revised April 12, 2018. COMMISSION AGENDA - Briefing Item No. 11b Meeting Date: May 26, 2026 • • • • • • • • Air Quality Plants and Animals Climate Recreation Hazardous Materials, Solid Waste, and Spill Prevention Historical Architectural, Archeological, and Cultural Resources Land and Shoreline Use Energy and Natural Resources Page 2 of 3 • • • • • • • • Noise Socioeconomics and Environmental Justice Surface Transportation Aesthetics, Light, and Glare Water Resources Public Services and Utilities Earth Housing The DEIS identified that surface transportation had significant impacts, but these impacts can be mitigated. There were other impacts identified, however these impacts did not exceed regulatory or human health standards and do not require any additional action. For many of these categories, the Port has incorporated minimization measures that currently minimize and will further reduce impacts into the future. For example, if these projects move forward there will be increases in air emissions that do not exceed the National Ambient Air Quality Standards (i.e., standards that meet human health requirements). The Port has many programs to minimize air emissions at SEA such as providing pre-conditioned air to aircrafts or implementing efficiencies to the central mechanical plant, both of which minimize fossil fuel use. There will be four public meetings in the cities of SeaTac, Burien, Des Moines, and Federal Way on June 22, 23, 25, and 27, as well as two virtual public meetings. These meetings will allow agencies and the public to speak with subject matter experts and submit comments. Agencies and the public will also have the option to provide comments during the 60-day public comment period by email, the project website (sea-samp.com), and by mail. The Port will provide a thorough and broad outreach that will include, and is not limited to, local, BIPOC (Black, Indigenous, and People of Color), and underrepresented communities. This includes using variety of media outlets, information on the project website, community meetings, and translating materials into multiple languages. Once the public comment period closes, the Port will review and respond to comments received and these comments will be considered within SEPA Final Environmental Impact Statement (FEIS). It is expected that the SEPA FEIS will be published in in late 2026. SCHEDULE Quarter 2 2026 Quarter 4 2026 SEPA Draft EIS released for public comment (5/22) + comment period (60 days: 5/22 - 7/21) SEPA EIS Final Document & Determination (Port issues decision document) + 21-day appeal period Template revised September 22, 2016. COMMISSION AGENDA - Briefing Item No. 11b Meeting Date: May 26, 2026 Page 3 of 3 ATTACHMENTS TO THIS BRIEFING (1) Presentation slides PREVIOUS COMMISSION ACTIONS OR BRIEFINGS March 24, 2026 - Commission Action: "Sustainable Airport Master Plan (SAMP) Near-Term Projects Environmental Review - Additional Contract Authorization" October 22, 2025 - Commission Briefing: "Sustainable Airport Master Plan Near-Term Projects Environmental Review - Draft NEPA Environmental Assessment Findings and Public Comment Period" June 27, 2023 - Commission Action: "Sustainable Airport Master Plan (SAMP) Near-Term Projects Environmental Review - Update and Budget Increase" February 25, 2020 - Commission Action: "Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTP) Environmental Review Briefing and Request for Additional Funds" January 28, 2020 - Commission Briefing: "Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTP) Environmental Review Briefing - Forecast and Schedule Update" February 26, 2019 - Commission Briefing: "Sustainable Airport Master Plan (SAMP) NearTerm Projects (NTP) Environmental Review Briefing - Scoping Report" May 8, 2018 - Commission Briefing: "Sustainable Airport Master Plan (SAMP) Planning and Environmental Update" February 13, 2018 - Commission Briefing: "Sustainable Airport Master Plan (SAMP) Planning Update" Template revised September 22, 2016.