TagThird Runway(1098)

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 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.

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.

Email from Ann Kenny (Ecology, Shorelands and Environmental Assistance Program) dated November 30, 2000, to Leslie Seffern (ATG) and Erik Stockdale, circulating a draft response letter to Bill Garrity, Executive Director of CECW (Consulting Engineers Council of Washington), regarding his November 22, 2000 letter challenging Ecology’s Request for Bid process for selecting a wetland consultant.

Final draft meeting notes from November 29, 2000 (9:30am–2:00pm) prepared by Kate Snider of Floyd & Snider Inc. for Sea-Tac Airport Third Runway 401 permit negotiations between Port Of Seattle (Elizabeth Leavitt, Michael Cheyne, Keith Smith) and Washington State Department of Ecology (Kevin Fitzpatrick, Ann Kenny, Dave Garland), with King County (David Masters, Kelly Whiting)

Draft Subsurface Conditions Data Report for Phase 4 Fill of the Third Runway Embankment at Sea-Tac International Airport, prepared by Hart Crowser (HartCrowser) for Port of Seattle and HNTB, dated November 29, 2000, project J-4978-28, AR 046207. Report covers generalized geologic conditions, subsurface soil conditions, hydrogeologic conditions, field exploration methods including auger borings, Standard Penetration

Memorandum dated November 27, 2000 from Dave Garland, NWRO Water Quality Program, Washington State Department of Ecology, to Ann Kenny (Shorelands and Environmental Assessment Program) and Kevin Fitzpatrick (Water Quality Program). Subject is wetland hydrology impacts from Port Of Seattle’s proposed excavation of Borrow Area 3 sand and gravel fill for the Sea-Tac Third Runway

Memorandum dated November 27, 2000 from Dave Garland, NWRO Water Quality, Washington State Department of Ecology, to Ann Kenny and Kevin Fitzpatrick regarding Sea-Tac Third Runway Borrow Area 3 wetland impacts. Addresses Port Of Seattle proposal to excavate sand and gravel from Borrow Area 3 south of Sea-Tac Airport for Third Runway fill embankment. References

Letter dated November 27, 2000 from Samuel R. Casne, Natural Resources Manager at Shannon & Wilson, Inc., to Erik Stockdale of the Washington State Department of Ecology (Shorelines & Environmental Assistance Program) in Bellevue, WA, proposing consulting services for review of the Natural Resource Mitigation Plan (NRMP) for the SeaTac Third Runway Project. The proposal,