Notes
Timeline and process flowchart document prepared for the Des Moines Airport Advisory Committee agenda of December 8, 2025, covering the NEPA (National Environmental Policy Act) and SEPA (State Environmental Policy Act) processes related to the Sea-Tac Airport Sustainable Airport Master Plan (SAMP). NEPA milestones include: 4-City ILA drafted 03/16/18; Des Moines and 4-City scoping comments 09/27/18; Draft EA issued 10/21/24; comment period 10/21/24–12/13/24; City Public Meeting 12/05/24; 4-City Comment Letter 12/12/24; Des Moines EA Comment Letter 12/13/24; FONSI/ROD issued 09/26/25; appeal period ended 11/24/25; 3-City ILA approved 11/13/25. Court NEPA Appeal process filed 11/24/25 (Petition for Review of FONSI/ROD), with FAA as respondent. SEPA milestones include: Determination completed 07/30/2018; Joint SEPA/NEPA Scoping 2018; Draft EIS anticipated Q1 2026. Document references Interlocal Agreements (ILA), Environmental Impact Statement (EIS), Finding of No Significant Impact (FONSI), Record of Decision (ROD), and the FAA administrative record and briefing schedule.