TagThird Runway(1067)

A fisheries biologist hired by the Airport Communities Coalition reviewed the Port of Seattle's permit application for the Miller Creek Relocation Project, raising serious scientific concerns about the proposed construction near Sea-Tac Airport. The review found that the project design lacked supporting scientific citations and calculations, and concluded that summer water temperatures would likely exceed safe levels for cutthroat trout for several years until riparian vegetation matured. Additional concerns were raised about inadequate water flow depths and the risk of the stream running dry due to highly porous spawning gravels used in the channel design.

A December 7, 2000 letter from the Port of Seattle to the Washington Department of Ecology responds to questions raised at a November 16, 2000 meeting regarding the Seattle-Tacoma International Airport Ground Water Study conducted under Agreed Order #97TC-122. The letter addresses the completion status of various research tasks, including hydrogeological surveys, contamination site identification, groundwater flow modeling, and pollution prevention for underground storage tank systems. The Port agrees with some of Ecology's assessments of incomplete tasks while disputing others, and clarifies its position on the scope of work required under the agreement.

Hart Crowser draft geotechnical engineering report (J-4978-28) prepared for HNTB, December 4, 2000, addressing the Third Runway embankment at Seattle-Tacoma International Airport, SeaTac, Washington. Covers embankment fill materials, slope stability analyses, foundation instability, subgrade improvements, liquefaction analysis (175-year and 475-year seismic events), FLAC deformation modeling, MSE walls (North Satellite Area, West, South), Phase 4 fill,

Wetland Functional Assessment and Impact Analysis prepared by Parametrix, Inc. for Port Of Seattle, Seattle-Tacoma International Airport, December 2000 (project number 556-2912-001). AR 048122. Covers wetland delineation, functional assessment, and impact analysis for Master Plan Update Improvements including Runway Safety Areas, relocation of South 154th Street, new Third Runway, borrow areas, and South Aviation Support

This December 2000 report by Parametrix, Inc. for the Port of Seattle presents a Comprehensive Stormwater Management Plan for Master Plan Update improvements at Seattle-Tacoma International Airport. It maps the airport's drainage basins, surrounding watersheds (including the Duwamish River, Des Moines Creek, and Miller Creek watersheds), and identifies pollution-generating and non-pollution-generating surfaces across the airport property. The plan outlines water quality treatment strategies for existing and proposed impervious surfaces to manage stormwater runoff from airport operations.

The Industrial Wastewater System (IWS) at Seattle-Tacoma International Airport was built in 1963 to collect and treat runoff from airport aprons, taxiways, hangars, and maintenance areas that may be contaminated by fuel spills, de-icing chemicals, and aircraft wash water. The system channels wastewater through two main drainage areas to an on-site treatment plant, with treated water ultimately discharged into Puget Sound under an NPDES permit. Ongoing upgrades aim to expand the system's capacity to handle a 25-year design storm event.

This December 2000 report assesses the impact of Seattle-Tacoma International Airport's Master Plan Update improvements on Pacific Coast salmon Essential Fish Habitat (EFH) in nearby waterways, including Miller Creek, Des Moines Creek, and the Green River Basin. Prepared by Parametrix, Inc. for the Federal Aviation Administration and the Port of Seattle, it evaluates water quality, aquatic habitat, and hydrological effects of airport expansion on local salmon species such as Chinook, Coho, and Pink salmon. The report also outlines conservation and mitigation measures proposed to offset adverse effects on salmon habitat in the airport's surrounding watersheds.

This technical document describes hydrological modeling conducted for the Seattle-Tacoma International Airport (Sea-Tac) Master Plan Update, focusing on stormwater runoff analysis for Des Moines Creek, Miller Creek, and Walker Creek subbasins. It details the calibration of computer models using rainfall and evaporation data spanning October 1948 through September 1996, along with parameters for airport embankment fill materials. The analysis was used to evaluate future stormwater detention facility requirements associated with airport expansion projects, including the Third Runway.

This document outlines the U.S. Army Corps of Engineers' analysis of a December 2000 mitigation plan developed by the Port of Seattle to offset wetland impacts caused by the construction of a third runway at Seattle-Tacoma International Airport. The plan covers roughly 18.6 acres of on-site wetland restoration near the airport—including the relocation of a stretch of Miller Creek and improvements to Lora Lake's shoreline—as well as 23.39 acres of off-site wetland mitigation in Auburn. Key goals include improving water quality, restoring floodplain and fish habitat, and managing vegetation to reduce wildlife hazards such as bird strikes near the airfield.

Wetland Delineation Report prepared by Parametrix, Inc. for Port Of Seattle, Seattle-Tacoma International Airport (Sea-Tac Airport), December 2000, project number 556-2912-001 (41). Report covers wetland delineation for Master Plan Update Improvements including North Employee Parking Lot, Runway Safety Area Extension, Third Runway project area, Borrow Areas 1 and 3, South Aviation Support Area (SASA)/Tyee Valley