Tagenvironmental assessment(33)

This section of the Seattle-Tacoma International Airport Environmental Assessment lists the individuals and organizations responsible for preparing the document, including staff from the FAA, Port of Seattle, and several consulting firms. The team covered a wide range of technical areas, with specialists handling noise analysis, air quality, surface transportation, wetlands, cultural resources, and public engagement. The assessment was produced in October 2024 as a draft under the airport's Sustainable Airport Master Plan for near-term projects.

This section of the Seattle-Tacoma International Airport Environmental Assessment examines cumulative impacts from past, present, and reasonably foreseeable future development projects at and around SEA airport, covering the period from 2017 through 2032. It reviews actions by the Port of Seattle and surrounding cities and agencies — including hotel construction, terminal expansions, and flight procedure changes — to assess how their combined environmental effects, such as noise, emissions, and land use changes, may affect nearby communities. Projects beyond 2032 or those in the long-term vision phase are excluded from detailed analysis due to insufficient specificity.

This October 2024 draft Environmental Assessment evaluates the potential environmental impacts of near-term construction and operational projects at Seattle-Tacoma International Airport under three alternatives: No Action, a Proposed Action, and a Hybrid Terminal Option. The analysis covers impacts through 2032 and an out-year of 2037, finding that increases in air quality emissions and effects on biological resources are not considered significant, with mitigation measures proposed for stormwater management and migratory bird nesting. Farmlands and Wild and Scenic Rivers were determined to have no presence in the study area and required no further analysis.

This draft Environmental Assessment from October 2024 examines the existing conditions around Seattle-Tacoma International Airport (SEA) as part of the Sustainable Airport Master Plan Near-Term Projects. Using 2022 as the baseline year, it describes SEA's location on approximately 2,800 acres in the City of SeaTac, situated 12 miles south of downtown Seattle and surrounded primarily by residential neighborhoods. The study covers a General Study Area of 3,692 acres to identify where proposed airport development actions could have direct or indirect environmental impacts on nearby communities.

This draft Environmental Assessment chapter from October 2024 outlines the process used to evaluate alternatives to proposed construction and expansion projects at Seattle-Tacoma International Airport (SEA). Using a two-step screening process, planners assessed public suggestions — such as building a new airport, using high-speed rail, or limiting growth — against the project's core purpose of serving 56 million annual passengers at an optimal level of service, rejecting most suggestions as unfeasible or insufficient. A No Action Alternative is also included, which assumes none of the proposed improvements would be built, though several independent projects already underway or planned by 2032 would still proceed.

This October 2024 Draft Environmental Assessment, prepared by Landrum & Brown for the Port of Seattle and the FAA, evaluates the environmental impacts of near-term construction projects at Seattle-Tacoma International Airport as part of its Sustainable Airport Master Plan. The assessment covers a wide range of environmental topics—including noise and noise-compatible land use, air quality, water resources, and environmental justice—for proposed improvements to passenger terminals, cargo facilities, airfield design, taxiways, and fuel storage. It is intended to support FAA decision-making under the National Environmental Policy Act (NEPA) and addresses the airport's ability to accommodate a projected 56 million annual passengers.

The Port of Seattle announced the release of a draft Environmental Assessment (EA) for Seattle-Tacoma International Airport's Sustainable Airport Master Plan (SAMP) on October 21, 2024, covering 31 near-term development projects including a second terminal, elevated busway, and new cargo facilities. The plan addresses projected regional population growth of one million people by 2035. Members of the public were invited to submit comments on potential environmental impacts during an open comment period running from October 21 to December 5, 2024.

The FAA issued a Negative Determination in July 2024, concluding that planned Near-Term Projects at Seattle-Tacoma International Airport (SEA) are not likely to cause coastal effects under the Coastal Zone Management Act. The projects include taxiway extensions, blast pad expansions, and relocation of navigational equipment across four airfield areas, with construction set to begin in 2026 over a six-year period. Because all FAA actions are confined to upland areas within the airport property, no significant impacts to Washington State's coastal zone resources were identified.

This document explains the noise metrics used to evaluate aircraft noise around Seattle-Tacoma International Airport, including decibels (dB), A-weighted decibels (dBA), and the Day-Night Average Sound Level (DNL). It describes how sound is measured on a logarithmic scale, meaning noise levels don't add up the way ordinary numbers do, and explains why A-weighted measurements are the standard used by the FAA and EPA because they best match how human ears perceive sound. These concepts form the technical foundation for assessing the environmental impact of proposed flight arrival procedures at Sea-Tac.

This document is Appendix D of the Final Environmental Assessment for proposed new arrival flight procedures at Seattle-Tacoma International Airport, dated November 1, 2012. It contains TARGETS files—technical routing data packages used to define new RNAV (area navigation) flight paths, such as the HAWKZ RNAV Version 4.2 procedure, which charts a series of waypoints guiding arriving aircraft toward Sea-Tac from the south. The files were prepared in coordination with Seattle ARTCC and are intended to support evaluation of how the new routes may affect noise levels in surrounding communities.