TagArmy Corp of Engineers(124)

Port of Seattle response to agency and public comments on Section 404 Clean Water Act permit application (JARPA, reference 1996-4-02325) for Master Plan Update improvements at Seattle-Tacoma International Airport. Covers U.S. Army Corps of Engineers public notice history (December 19, 1997; September 30, 1999; December 27, 2000), wetland fill acreages, Miller Creek channel relocation, Highline

Memorandum for Record (MFR) dated 24 April 2001 from CENWS-OD-RG summarizing telephone conversations with Elizabeth Leavitt and Jim Kelley (Port of Seattle consultants) on 9-10 April 2001 regarding the Army Corps of Engineers’ review of the Port’s draft responses to letters from Azous and Sheldon concerning the Third Runway project at Sea-Tac Airport. Corps comments

This April 2001 memorandum summarizes a meeting between Corps of Engineers staff and Port of Seattle representatives (Elizabeth Leavitt and Jim Kelley) regarding the Port's submission of additional information related to the Third Runway project at Sea-Tac Airport. The parties discussed an approach to assessing cumulative environmental impacts, including the use of 1930s aerial photos and historical soil surveys to estimate wetland impacts from past airport construction. Several technical reports and construction drawings related to retaining wall designs along Miller Creek were also submitted for review.

This is a catalogued index of documents from 2001 related to the proposed Third Runway at Seattle-Tacoma International Airport, covering regulatory filings, public comments, and environmental studies. It includes records from agencies such as the Department of Ecology, the Corps of Engineers, and King County, addressing topics like stormwater management, NPDES permits, groundwater studies, and the impact of the February 2001 Nisqually Earthquake on airport structures. The catalog serves as a reference guide directing researchers to archival notebooks and specific shelf locations where the full documents are stored.

A March 28, 2001 letter from the Washington State Department of Ecology clarifies that lands classified as 'prior converted croplands' by the US Army Corps of Engineers are still subject to state wetland regulations if they meet the criteria outlined in the 1996 Washington State Wetland Delineation and Identification Manual. While the federal Food Security Act may exempt such lands from Clean Water Act Section 404 requirements, this exemption does not extend to state law. As a result, some wetlands may be free from federal oversight but remain fully regulated under Washington State rules.

Handwritten meeting notes dated 3-22-01 (AR018222–AR018224), participants Ann Kenny, Kelly Whiting, Katie Walters, at SKW MIG/WCED. Notes cover stormwater pond analysis including Pond D (discharge not modelled, serves SDWIB, 0.2 cfs infiltration facility capacity, seasonal groundwater at 336 ft, intercepts hydrology to wetland), Pond F (discharges to Walker Creek via riprap outfall, 2-yr flow 1.2

Handwritten meeting notes dated 3-22-01 (AR 018495–018497, Exhibit 192) from a meeting involving Kelly Whiting, Katie Walters, and others (SKW MIG at WLRD). Notes cover Pond D (discharge not modelled, meets flow standards, indirect impacts to wetlands, SDW1B, seasonal groundwater at 336 ft, infiltration facility 0.2 cfs), Pond F (discharges to Walker Creek via riprap

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.

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.

In February 2001, GeoSyntec Consultants submitted a technical review letter to the U.S. Army Corps of Engineers and Washington State Department of Ecology on behalf of the Airport Communities Coalition, raising serious concerns about the proposed Third Runway expansion at Seattle-Tacoma International Airport. The letter identified significant deficiencies in the geotechnical investigation, analysis, and design of the planned embankment fill and West Mechanically Stabilized Earth (MSE) Wall, warning that the project's foundations involved weak peat and liquefiable sands in a highly seismic area. GeoSyntec concluded that the available data was insufficient to confirm the safety of what would be the tallest MSE wall in the world, and that approval should not be granted without a more thorough geotechnical review.