TagWater Quality(475)

This section of the Sea-Tac Airport Master Plan Update Environmental Impact Statement examines how proposed airport expansion alternatives would affect water quality and hydrology in the surrounding area, particularly Miller Creek and Des Moines Creek. The analysis finds that increased impervious surfaces would raise stormwater runoff volumes and peak flow rates, potentially causing downstream flooding and erosion, but that required detention storage facilities and mitigation measures would largely prevent significant water quality degradation. Both creeks, while classified as Class AA extraordinary waters, already show some pollution from urban stormwater runoff, though deeper regional groundwater used for drinking remains unaffected.

Fish biologist Donald E. Weitkamp submitted this declaration opposing a legal challenge to Sea-Tac Airport's expansion plans, arguing that the airport's stormwater controls and water quality measures adequately protect nearby streams. He concluded that the headwater portions of Miller, Walker, Des Moines, and Gilliam Creeks near the airport are unlikely to support chinook or chum salmon, as urbanization has altered those streams to favor warm-water species instead. The declaration supports the Port of Seattle's position that its Master Plan Update projects meet environmental standards and will not significantly harm local aquatic resources.

In this 2001 legal declaration, Washington Department of Ecology official Kevin Fitzpatrick addresses water quality concerns raised by the Airport Communities Coalition regarding stormwater discharges from Seattle-Tacoma International Airport during its Third Runway expansion. Fitzpatrick explains that while stormwater discharges have shown elevated levels of copper, lead, and zinc, these instantaneous exceedances do not necessarily constitute violations of state water quality standards, since stormwater fluctuates rapidly by nature. He further outlines steps the Port of Seattle was taking to address pollution, including rerouting de-icing runoff, replacing zinc-emitting metal roofs, and conducting required studies to establish specific effluent limits under the Clean Water Act 401 Certification.

This document outlines Washington State water quality standards for surface waters, including criteria for total phosphorus levels in lakes across different ecoregions (Cascades and Columbia Basin) and limits for toxic substances such as heavy metals, pesticides, and radioactive materials. It establishes trophic state classifications and action values that trigger lake-specific studies when exceeded, and sets numerical criteria for aquatic life protection in both freshwater and marine environments.

This document is the curriculum vitae of Dr. Peter Willing, a water resources consultant based in Bellingham, Washington, who was retained to review surface and ground water hydrology related to the possible construction of a third runway at Sea-Tac Airport from November 1999 to February 2001. His investigation addressed issues including stormwater management effectiveness, compliance with the King County Surface Water Design Manual, and potential project effects on wetlands, stream flows, and anadromous fish. Dr. Willing holds a Ph.D. from Cornell University and has broad experience in flood analysis, water rights, and geohydrologic investigations across the Pacific Northwest.

Prefiled direct testimony of Dr. Charles S. Wisdom (Senior Project Manager, Parametrix, Inc.) before the Pollution Control Hearings Board (PCHB), case No. PCHB 01-160, filed on behalf of respondents Department of Ecology and Port Of Seattle against appellants Airport Communities Coalition (ACC) and Citizens Against Sea-Tac Expansion (CASE). Wisdom holds a Ph.D. in Chemical Ecology

NPDES Permit WA-002465-1 fact sheet for the Seattle-Tacoma International Airport (STIA), issued to the Port Of Seattle. Establishes basis for effluent limitations and requirements for discharge of treated industrial wastewater to Puget Sound (WA-PS-0270) and stormwater to Miller Creek (WA-09-2005), Des Moines Creek (WA-09-2000), and the City of SeaTac storm sewer, tributary to Gillian Creek

Prefiled testimony of Dr. Michael Riley, Civil Engineer, in PCHB No. 01-160, Airport Communities Coalition (ACC) v. State of Washington Department of Ecology and Port Of Seattle. Riley performed modeling analysis of fill criteria in the 401 Certification for the Third Runway embankment at Sea-Tac Airport, using conservative assumptions including maximum metal concentrations allowed by

Table 4 Stormwater Quality Comparators comparing water quality data across multiple study sites including NURP 1983, BURP 1984, Metro 1982, Bellevue 1995, Highway Runoff 1981, Portland NPDES 1993, and STIA Landside and Airfield locations. Parameters measured include pH, TPH, fecal coliforms, BOD5, TSS, turbidity, glycols, copper (Cu), lead (Pb), and zinc (Zn) in units of

Revised direct testimony of Dave Garland, hydrogeologist and Watershed Unit supervisor at Washington State Department of Ecology Northwest Regional Office, submitted on behalf of Ecology in PCHB No. 01-160. Proceeding involves Airport Communities Coalition (ACC) and Citizens Against Sea-Tac Expansion (CASE) as appellants against Ecology and Port Of Seattle as respondents. Garland describes his 24-year