TagEnvironmental Impact Statement(400)

Biological Assessment prepared by Parametrix, Inc. for the Federal Aviation Administration and Port Of Seattle regarding reinitiation and initiation of Section 7 ESA consultation for Seattle-Tacoma International Airport Master Plan Update Improvements. Covers ESA-listed species managed by USFWS and NMFS including Chinook salmon, bull trout, and essential fish habitat (EFH). Analyzes hydrologic systems including Miller

Port Of Seattle SEPA Addendum (POS SEPA No. 00-07) dated May 5, 2000, to the Final Supplemental Environmental Impact Statement for the Proposed Master Plan Update Development Actions at Seattle-Tacoma International Airport (STIA), issued jointly by FAA and Port Of Seattle in May 1997. Documents the Auburn Wetland Mitigation Project on an approximately 67-acre parcel

Northwest Hydraulic Consultants submitted follow-up technical comments in May 2000 raising serious concerns about flawed stormwater modeling used to assess the impact of a proposed third runway at Seattle-Tacoma International Airport. The consultants identified major inconsistencies in soil-type assumptions and runoff parameters in the hydrologic models, concluding that the Stormwater Management Plan's predictions of detention facility performance were unreliable and required a complete overhaul. The letter also flagged a lack of adequate local regulatory oversight to ensure that Port of Seattle stormwater designs complied with King County surface water standards.

A technical review by Northwest Hydraulic Consultants, submitted to the U.S. Army Corps of Engineers and Washington State Department of Ecology in May 2000, raises serious concerns about the stormwater management plan for Seattle-Tacoma International Airport's proposed third runway. The report identifies major flaws in the hydrologic modeling used to assess drainage impacts, including inconsistent soil-type assumptions and unreliable flow predictions for Miller Creek. The consultants call for a complete overhaul of the modeling process, independent technical review, and clearer regulatory oversight of the Port of Seattle's stormwater design work.

SEPA Addendum (April 27, 2000) prepared by Port Of Seattle and FAA as addendum to the Final Supplemental Environmental Impact Statement for the Proposed Master Plan Update Development Actions at Seattle-Tacoma International Airport (STIA), and to the SEPA Environmental Checklist for the Auburn Wetland Mitigation Project (August 1998). Documents modification to Master Plan Update wetland

A February 2000 email from hydraulic consultant Bill Rozeboom argues that the proposed expansion of Sea-Tac Airport's Integrated Wetlands System (IWS) lagoon—tripling its storage capacity—is primarily driven by the airport's Master Plan Improvements, including the proposed third runway, rather than being a routine water quality project. Rozeboom notes that the planned increase in impervious drainage area (roughly 521 additional acres) closely mirrors the proposed increase in IWS storage volume, supporting his conclusion that the third runway is the primary driver of the expansion. He also raises concerns that the environmental documents fail to adequately assess the impact of large-scale out-of-basin water transfers on aquifer recharge and stream base flows in the Miller Creek and Des Moines Creek basins.

Internal forwarded email chain dated January 28, 2000, from Erik Stockdale to Tom Luster (copying Sarah Suggs original), forwarding a SEPA register entry (Ecology File# 200000524, LA File# 00-02) for an Addendum EIS issued by the Port of Seattle as lead agency. The addendum EIS covers Third Runway Wetland Fill and Temporary Construction at Sea-Tac

SEPA Addendum dated January 24, 2000, Port Of Seattle, POS SEPA No. 00-02, addressing modifications to the Master Plan Update Development Actions for the Third Parallel Runway at Seattle-Tacoma International Airport. Addendum covers: (1) increased wetland acreage affected by the project, revised from 12.23 acres to 18.33 acres, with 15.41 acres affected by the runway

A November 1999 technical letter from Northwest Hydraulic Consultants, submitted on behalf of the Airport Communities Coalition, identifies major deficiencies in the proposed stormwater management plan for Seattle-Tacoma International Airport's 3rd runway development. The review finds that the plan fails to comply with the 1998 King County Surface Water Design Manual and Washington State Department of Ecology guidelines, including requirements for large-site drainage reviews, offsite analysis, and flow control. The consultants warn that if the plan is approved as written, it could cause significant adverse impacts to downstream creek systems, including Miller Creek and Des Moines Creek.

Parametrix, Inc. prepared this Supplemental Airport Site Wetland and Stream Analysis for Port Of Seattle, dated November 12, 1999 (AR 043120). The report analyzes wetland and stream conditions at three supplemental airport candidate sites — Arlington, Lake Sawyer, and Frederickson — comparing 1994 MSA study findings with 1998 field-verified wetland boundary data. Includes tables comparing