Tagenvironmental assessment(30)

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 contains a January 2019 invoice from the law firm Lockridge Grindal Nauen P.L.L.P. to the City of Burien for $1,275 in legal services related to Preliminary Environmental Assessment Modeling, covering 5 hours of work by five attorneys. The invoice was revised in April 2019 to correct hourly rates in line with a contract amendment, and payment was approved by the City of SeaTac's Community & Economic Development Director after confirmation that the contract had been corrected.

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.

This appendix from a 2012 Environmental Assessment documents the published arrival flight procedures at Seattle-Tacoma International Airport that would be affected by proposed changes to how aircraft approach the airport. It includes detailed charts for routes such as the JAWBN Three Arrival and Olympia Seven Arrival, showing waypoints, altitudes, and speed restrictions for aircraft arriving from various directions including Canada and southern Washington. These procedures define the flight paths aircraft must follow when descending into Sea-Tac, directly influencing the noise experienced by communities surrounding the airport.