TagAirport Communities Coalition(272)
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2001-03-02
EXH AR021820: GeoSyntec Correction Comment #7 Pseudo-Static Seismic Stability Third Runway Wall ACC Technical Review
In March 2001, GeoSyntec Consultants submitted a correction to a technical review letter concerning the Third Runway Project at Seattle-Tacoma International Airport, clarifying that the seismic stability analysis used by Hart Crowser may seriously overestimate—not underestimate—the wall's ability to withstand earthquake loads. The firm argued that analyzing only the failure surface with the lowest static safety factor, rather than independently searching for the critical seismic failure surface, is an incorrect methodology. GeoSyntec recommended a proper pseudo-static slope stability analysis to ensure adequate ground improvement measures are applied in the right areas. -
2001-02-16
EXH AR023036: ACC Comment Letter — Azous Environmental Sciences Review Third Runway Wetland Stream Fisheries Impacts
A February 2001 letter from Azous Environmental Sciences, submitted on behalf of the Airport Communities Coalition, critiques the Port of Seattle's environmental mitigation plan for the proposed third runway at Seattle-Tacoma International Airport. The letter argues that key analyses of wetland functions, permanent and temporary wetland area losses, and cumulative environmental impacts are missing or scientifically unsupported in the Port's December 2000 documents. The author concludes that federal and state agencies lack sufficient information to determine whether the project complies with the Clean Water Act or whether the proposed mitigation adequately offsets the project's adverse impacts on wetlands, streams, and fisheries. -
2001-02-16
EXH AR021162: Water Resources Consulting Letter to Army Corps & Ecology — STIA Section 404 Permit Water Quality Review
A water resources expert hired by the Airport Communities Coalition reviewed the Port of Seattle's stormwater management plan for Sea-Tac Airport expansion and found serious water quality concerns. The review concluded that the plan would harm surrounding streams and aquifers, that existing pollution controls were already failing to meet Washington State water quality standards, and that the proposed measures offered no reasonable assurance of future compliance. The expert recommended denial of both the Clean Water Act Section 401 certification and the Section 404 permit approval. -
2001-02-16
Comments on Seattle Tacoma International Airport Project: Third Runway – Embankment Fill and West MSE Wall, and Industrial Wastewater System Lagoon #3 Expansion Project on Second Public Notice
In February 2001, engineering firm GeoSyntec Consultants submitted a technical review letter on behalf of the Airport Communities Coalition, raising serious concerns about the proposed Third Runway expansion at Seattle-Tacoma International Airport. The review identified significant deficiencies in the geotechnical investigation and analysis supporting construction of the embankment fill and West MSE Wall, including insufficient soil strength data and inadequate seismic safety assessments. GeoSyntec warned that the proposed design — which would result in the world's tallest MSE wall built over weak, potentially unstable soils in a seismically active region — could fail under earthquake conditions, threatening both airport operations and nearby natural resources. -
2001-02-15
EXH 309: NHC Letter — ACC Technical Review Comments Stormwater Hydrology Hydraulics STIA Third Runway December 2000 SMP
In February 2001, Northwest Hydraulic Consultants submitted technical review comments to the U.S. Army Corps of Engineers and Washington State Department of Ecology on behalf of the Airport Communities Coalition, raising concerns about the stormwater management plan for the proposed third runway at Seattle-Tacoma International Airport. The letter identified multiple deficiencies, including dam safety issues, vault structures that violated King County depth requirements, inadequate methods for assessing standing open water durations, and insufficient erosion and sediment control planning. These issues, the consultants warned, could pose risks to both structural safety and safe airport operations if not addressed prior to project approval. -
2001-02-15
EXH 243: NHC Letter to Army Corps & Ecology — ACC Comments Stormwater Hydrology Hydraulics STIA Third Runway Dec 2000 SMP Review
A February 2001 technical review letter from Northwest Hydraulic Consultants, submitted on behalf of the Airport Communities Coalition, raises concerns about the stormwater management plan for Seattle-Tacoma International Airport's proposed third runway expansion. The letter identifies deficiencies in hydrology and hydraulics analyses, inconsistencies in stormwater detention standards, and the lack of a clear independent review process for the complex project. Reviewers warn that without stricter oversight and well-defined engineering requirements, the development risks significant adverse impacts to local streams and wetlands, particularly Miller Creek and Des Moines Creek. -
2001-02-15
EXH AR019027: ACC Technical Review Letter — Stormwater Hydrology Hydraulics Comments STIA Third Runway SMP Dec 2000
A February 2001 technical review letter from Northwest Hydraulic Consultants, submitted on behalf of the Airport Communities Coalition, raises serious concerns about the stormwater management plans for Seattle-Tacoma International Airport's proposed third runway expansion. The review identifies multiple technical deficiencies in the project's hydrology and drainage designs, warning that they could cause significant adverse impacts to local streams and wetlands, particularly Miller Creek and Des Moines Creek. The letter also criticizes the lack of clearly defined stormwater control standards, absence of independent design review processes, and failure to provide financial guarantees for implementing the stormwater management plan. -
2000-12-19
EXH 371: Columbia Biological Assessments Letter to EPA Region X – Contaminated Fill, MTCA Method A Standards, Third Runway
A scientist retained by the Airport Communities Coalition wrote to the EPA in December 2000, raising serious concerns about the Port of Seattle accepting contaminated fill materials for the proposed Third Runway project at Seattle-Tacoma International Airport. The letter argues that the Port improperly used Washington State's Model Toxics Control Act (MTCA) cleanup standards as fill acceptance criteria, when those standards were designed to clean up existing contaminated sites, not to permit introducing pollution onto previously clean land. The scientist also criticizes the Port's soil testing methods as statistically inadequate to detect the true extent of contamination, warning that chemicals in the fill could leach into groundwater, wetlands, and surface water including Miller Creek. -
2000-12-08
EXH 370: Letter Columbia Biological Assessments to WDFW Reviewing JARPA Miller Creek Project
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. -
2000-10-25
EXH AR023709: ACC Letter to Ecology Director Fitzsimmons Protesting Removal of Tom Luster from Third Runway 401 Permit Process
In an October 25, 2000 letter to Washington State Department of Ecology Director Tom Fitzsimmons, the Airport Communities Coalition (representing cities of Burien, Tukwila, Des Moines, Federal Way, Normandy Park, and the Highline School District) protested the removal of senior environmental specialist Tom Luster from the Port of Seattle's third runway 401 water quality permit review. The coalition alleged that political pressure from the Port of Seattle — including secret meetings with the Governor's office and a coordinated public relations campaign — was improperly influencing the regulatory process. The letter demanded Luster's immediate reinstatement, citing his three years of institutional knowledge and commitment to science-based, nonpolitical decision-making on the permit.