TagArmy Corp of Engineers(124)

A December 2002 letter to the U.S. Army Corps of Engineers raises environmental and public health concerns about the Sea-Tac Airport Third Runway project, arguing that construction pollution, ASARCO-contaminated fill material, and increased de-icing fluid use may be harming Puget Sound marine life, including orca populations. The author also warns of collision risks between barges transporting runway fill material and large tankers crossing the same waters. The letter calls for denial of the third runway permit, citing the absence of any cumulative air pollution or health hazard analysis and questioning the project's necessity given declining air and marine cargo traffic.

Memorandum of Agreement (MOA) between the U.S. Department of the Army and the U.S. Environmental Protection Agency (EPA) articulating policy and procedures for determining type and level of mitigation required under Clean Water Act (CWA) Section 404(b)(1) Guidelines. AR037425. Covers three mitigation types: avoidance, minimization, and compensatory mitigation; establishes no net loss of wetlands goal;

National Research Council publication by the Committee on Mitigating Wetland Losses, Board on Environmental Studies and Toxicology, and Water Science and Technology Board titled ‘Compensating for Wetland Losses Under the Clean Water Act.’ AR034586, Exhibit-2178. Covers mitigation compliance standards including jurisdictional hydrology, wetland delineation, hydrological performance standards, design standards for mitigation sites, USACE wetland filling

Draft map (AR 035005, Exhibit 1015) showing restrictive covenant boundaries, sewer line easements, IWS line, Des Moines Creek, and surveyed OHWM on the south end of Seattle-Tacoma International Airport. Identifies the Tyee Valley Golf Course Mitigation Area and Des Moines Creek Mitigation Area, with a note that mitigation was required by the Washington State Department

This 2001 Memorandum of Agreement between the U.S. Army and the EPA outlines the policies and procedures for determining what types of mitigation are required when issuing permits for discharging dredged or fill material into waters under Clean Water Act Section 404. It establishes a three-step mitigation sequence — first avoiding impacts, then minimizing unavoidable impacts, and finally providing compensatory mitigation for any remaining harm — with a goal of no overall net loss of wetlands. The document provides guidance to Army Corps of Engineers and EPA field personnel on how to evaluate standard permit applications in compliance with these environmental protection standards.

AR 018450 (DOE Misc 0033, Exhibit 191). Handwritten notes from a conference call between Seattle and City of Des Moines discussing what emergency action will override Section 401, Army Corps of Engineers regulation of indirect impacts, buffer activity language, and mitigation design. Dennis Ostencorp referenced as thinking about writing a letter on circular and mitigation

Exhibit AR018442 is a detailed map of wetland and stream impacts in the Miller Creek Basin associated with the Seattle-Tacoma International Airport Third Runway project. The map shows delineated wetlands verified by the Army Corps of Engineers (ACOE), wetlands not verified by ACOE, water features, Third Runway embankment, Runway Safety Areas (RSAs), relocated S 154th

Pre-filed testimony of W. A. Rozeboom, M.B.A., P.E. submitted to the Environmental Hearings Office (PCHB), received March 18, 2002, consisting of an index to exhibits A through P. Exhibits include Northwest Hydraulic Consultants letters to U.S. Army Corps of Engineers (November 1999, February 2001, June 2001, December 2001) commenting on stormwater, hydrology, and hydraulics of

A February 2002 technical letter from GeoSyntec Consultants, written on behalf of the Airport Communities Coalition, raises concerns about the Port of Seattle's low flow analysis for the Sea-Tac Airport Third Runway expansion project. The letter argues that the Port's analysis fails to account for the years-long delay before water would flow through the new embankment fill into drainage systems feeding nearby creeks, potentially leaving those creeks without adequate water during the critical early years of operation. GeoSyntec concludes that the Port has not demonstrated the project's storage vaults are properly sized, and that the underlying computer models are unreliable due to lack of calibration and flawed assumptions about soil hydraulic conductivity.

A February 2002 technical letter from GeoSyntec Consultants, submitted to the U.S. Army Corps of Engineers on behalf of the Airport Communities Coalition, raises serious concerns about the Port of Seattle's water flow analysis for the proposed Sea-Tac Third Runway expansion. The letter argues that the Port's analysis fails to account for the years-long delay before water would flow through the new embankment fill into drainage systems, potentially leaving nearby creeks without adequate water during the critical early years of operation. GeoSyntec concludes that the storage vaults designed to protect creek water levels may be significantly undersized due to flawed modeling assumptions and an overestimation of how quickly water would move through the embankment soil.