TagACC(1534)

This February 2001 report by Herrera Environmental Consultants presents a five-year summary of water quality monitoring conducted for the City of Des Moines, Washington, covering three creek basins: Des Moines Creek, Massey Creek, and North Fork McSorley Creek. The report examines a range of water quality parameters including temperature, pH, dissolved oxygen, metals, nutrients, turbidity, and fecal coliform bacteria, as well as benthic invertebrate conditions as indicators of stream health. It was prepared for the City's Surface Water Management Utility and provides data intended to inform stormwater and surface water management decisions in the Des Moines area near Sea-Tac Airport.

A fisheries biologist writing on behalf of the Airport Communities Coalition argues that the Port of Seattle has not provided sufficient scientific evidence to justify a Clean Water Act Section 404 permit for its proposed third runway expansion at Seattle-Tacoma International Airport. The letter contends that the project would harm local streams (Miller Creek, Walker Creek, and Des Moines Creek) and their fish populations — including federally threatened Chinook salmon — through stream relocation, contaminated fill materials, and toxic stormwater runoff containing copper, zinc, and de-icing chemicals. The author concludes that the U.S. Army Corps of Engineers lacks an adequate scientific basis to approve the permit without additional environmental study and mitigation measures.

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.

A fisheries biologist hired by the Airport Communities Coalition argues that the Port of Seattle has not provided sufficient scientific evidence to justify a Clean Water Act Section 404 permit for its proposed third runway project at Seattle-Tacoma International Airport. The report concludes that the Port's plans would harm wetlands, streams, and fish populations—including federally threatened Chinook salmon—in the Miller Creek, Walker Creek, and Des Moines Creek watersheds through contaminated fill, toxic stormwater runoff, and the rerouting of Miller Creek. The biologist urges the U.S. Army Corps of Engineers to require additional environmental studies and water quality modeling before any permit decision is made.

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.

A February 2001 letter from law firm Helsell Fetterman, representing the Airport Communities Coalition (cities of Burien, Des Moines, Federal Way, Normandy Park, Tukwila, and the Highline School District), urges the U.S. Army Corps of Engineers and Washington State Department of Ecology to deny the Port of Seattle's permits for the proposed Sea-Tac third runway. The letter argues that the Port had already spent nearly $300 million on construction before receiving required Clean Water Act approvals, and that its application lacked adequate stormwater management plans and failed to meet water quality standards. Independent experts retained by the coalition found the Port's environmental mitigation proposals to be technically flawed, incomplete, and legally insufficient.

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.

Sheldon & Associates letter dated February 15, 2001, responding to public notice comments regarding the Seattle-Tacoma International Airport Masterplan Update Projects Section 404/401 Permits. Addresses movement of water through embankment fill and Mechanically Stabilized Earth (MSE) wall, drainage layer design to prevent excess pore pressures, rock underdrain clogging prevention using Group 1A filter material, shallow

A 2001 environmental review letter from Sheldon & Associates, commissioned by the Airport Communities Coalition, challenges the Port of Seattle's technical documents for the proposed Third Runway at Seattle-Tacoma International Airport. The review finds that the Port has not adequately demonstrated that massive fill placement and engineered retaining walls would avoid long-term damage to downslope wetlands, groundwater flows, and Miller Creek. Key unresolved concerns include the reliability of the proposed underdrain system, incomplete baseline data, and the lack of independent construction oversight.

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.