TagSea-Tac Airport(2027)

This document summarizes the environmental wetland impacts associated with airport expansion projects near Sea-Tac Airport, detailing acreage affected across four creek basins — Miller Creek, Walker Creek, Des Moines Creek, and Green River. It breaks down impacts by wetland vegetation type (forested, shrub, emergent, and open water) and hydrological classification (depressional, riverine, and slope), with total impacts ranging from 4% of the Walker Creek project area to 100% of the Green River area. The tables also distinguish between temporary and permanent wetland impacts as determined by the U.S. Army Corps of Engineers, covering features such as the Third Runway and Runway Safety Area extensions.

This map document illustrates the planned Third Runway expansion at Seattle-Tacoma International Airport, showing the proposed runway location, construction staging area, and fill 'borrow' areas in the Sea-Tac region. The map covers surrounding communities including Burien, Normandy Park, and Des Moines, and highlights nearby waterways such as Des Moines Creek, Miller Creek, and Walker Creek that could be affected by construction. Based on the 1996 Port of Seattle EIS Sea-Tac Airport Master Plan and 1997–1998 King County Wetlands Maps, the document provides geographic context for environmental and land-use planning related to the runway project.

This document is a draft National Pollutant Discharge Elimination System (NPDES) waste discharge permit issued by the Washington State Department of Ecology to the Port of Seattle for Sea-Tac International Airport. It governs the discharge of treated industrial wastewater into Puget Sound and stormwater runoff into nearby waterways including Des Moines Creek, Miller Creek, and Walker Creek. The permit sets effluent limits, monitoring requirements, and reporting obligations to protect water quality in the receiving waters.

This NPDES permit fact sheet for Seattle-Tacoma International Airport details the locations and receiving waterways for all stormwater and industrial wastewater discharge outfalls at the facility. It covers three categories of discharge: industrial wastewater flowing to Puget Sound, stormwater from industrial activities flowing to local waterways such as Des Moines Creek, Miller Creek, and Northwest Pond, and stormwater from construction activities discharged to Des Moines Creek, Miller Creek, Walker Creek, and Gilliam Creek. The document lists both existing and future planned outfall locations with precise latitude and longitude coordinates for each discharge point.

The Puget Sound Regional Council adopted resolutions in 1993 and 1996 establishing the region's long-term commercial air transportation policy, concluding that a third runway at Seattle-Tacoma International Airport (Sea-Tac) should be pursued alongside additional noise reduction measures. The council determined that small supplemental airports, including Paine Field, would not serve as alternatives for meeting regional commercial air capacity needs. These decisions were incorporated into the 1995 Metropolitan Transportation Plan and are maintained in the Destination 2030 regional transportation framework.

The Sea-Tac/Communities Plan outlines three noise impact programs for managing properties affected by aircraft noise at Seattle-Tacoma International Airport. All three programs involve a designated government unit purchasing affected properties through negotiation or condemnation. The programs differ in how the land is subsequently used: Program One converts it to low-intensity open space such as golf courses or farmland; Program Two redevelops it for noise-compatible industrial or commercial uses; and Program Three leases the properties back to prior owners for a set period, leaving land use largely unchanged in the short term.

This document contains official corrections and modifications to the Highline Communities Plan, a land-use planning document for communities near Sea-Tac Airport in King County, Washington. It addresses errata such as street name corrections, zoning designation changes, and map updates, as well as adopted modifications related to hazard area development, Planned Unit Developments (PUDs), and a notable recognition of Boeing's proposed corporate headquarters on Port of Seattle property west of Sea-Tac Airport. The modifications also acknowledge that an environmental impact statement was being prepared by King County regarding the Boeing proposal, while community input had not yet been formally gathered.