TagPollution Control Hearings Board(1532)

Final draft meeting notes from July 5, 2001 technical meeting on 401 Permit Decision-Making for the Sea-Tac Airport Third Runway, prepared by Rachel McCrea of Floyd & Snider Inc. Attendees include Ann Kenny (Dept. of Ecology), Kelly Whiting (King County), Keith Smith (Port of Seattle), Felix Kristanovich (Foster Wheeler), Paul Fendt and Tom Atkins (Parametrix),

Water Resources Consulting LLC submitted technical comments in July 2001 on behalf of the Airport Communities Coalition, challenging the Port of Seattle's stormwater management plans for SeaTac Airport expansion. The document disputes Port claims about impervious surface increases, water diversions affecting Miller, Walker, and Des Moines creeks, and the effectiveness of bioswale filtration systems for removing pollutants such as metals from airport runoff.

In a July 2, 2001 email chain, Kelly Whiting of Metro King County raises concerns about the analysis of 'non-hydrologic' effects related to water rights relinquishments and their impact on summer low flows in a Sammamish River watershed study. Whiting questions the assumptions made about non-respondents to a water withdrawal survey, arguing that the rates assigned to them appear disproportionately high compared to trends shown by actual survey respondents. The email requests a walkthrough during an upcoming Thursday meeting to clarify how these figures would be incorporated into a low-flow mitigation plan.

A July 2001 email from King County engineer Kelly Whiting summarizes ecological recommendations regarding proposed stream flow mitigation measures. A lead stream ecologist advised that mitigation plans be compared against existing stream hydrology to avoid abrupt changes that could disrupt biological processes, such as sudden summer flow increases confusing fish behavior. The ecologist also emphasized that water quality factors like temperature and dissolved oxygen are as important as flow rates, and suggested introducing reserved water gradually through ponds or wetlands rather than directly into streams.

Port Of Seattle memo opposing Airport Communities Coalition (ACC) motion for stay in PCHB No. 01-133, Volume 2 of 3, containing Declaration of Paul S. Fendt and SMP Volume 3 materials. Includes preface to the Comprehensive Stormwater Management Plan (SMP) for Seattle-Tacoma International Airport Master Plan Update Improvements, July 2001, with replacement pages developed in

This table from a July 2001 Comprehensive Stormwater Management Plan summarizes drainage area measurements and changes in impervious surfaces (such as pavement and rooftops) across Miller Creek, Walker Creek, and Des Moines Creek watersheds at Seattle-Tacoma International Airport (STIA). It compares 1994 baseline conditions to projected 2006 future conditions, showing a total increase of approximately 305.7 acres of impervious area across all drainage basins. The data was compiled from GIS coverage to support stormwater management planning for the airport's master plan update.

This section of Sea-Tac International Airport's Comprehensive Stormwater Management Plan outlines proposed Master Plan Update (MPU) improvements and their likely stormwater management requirements. It describes how land use changes — including increases in impervious surfaces across various airport development phases — were analyzed using GIS and hydrologic modeling to assess drainage impacts. The document also notes that projects such as the relocated Airport Surveillance Radar required specific flow controls to manage stormwater runoff on the west side acquisition area.

This document is Table A-3 from the Sea-Tac Airport Master Plan Update, outlining construction projects that require stormwater management. It details activities such as runway safety improvements, taxiway construction, terminal expansions, and embankment work, noting for each whether permanent stormwater detention was provided, the construction timeline, and the type of drainage facility used. Projects are categorized as either new or retrofit stormwater installations, with comments describing impervious surface impacts and drainage routing to temporary or permanent detention facilities.

This document describes the Integrated Water System (IWS) stormwater management configuration at Seattle-Tacoma International Airport (Sea-Tac), detailing storage lagoons totaling 76.9 million gallons and a treatment rate of 4.0 million gallons per day across approximately 435 acres. Simulations over a 50-year period confirmed zero overflow events under proposed conditions, with overflows only beginning to occur if treatment rates dropped below 3.1 million gallons per day. The system experienced only one historical overflow during an extreme rain-on-snow event in December 1996–January 1997, with no petroleum hydrocarbons detected downstream.

STIA construction site stormwater monitoring report dated 6/28/01, sampled by K. Ludwa and J. Brandt. Documents monitoring of multiple construction sites including Third Runway Embankment Phase 4, S. 160th St. Detention Ponds, S. 157th Pl. Detention Pond, North Safety Fill Construction, Third Runway Embankment Phase 3, North Runway Embankment Phase 3, Wetland 44a, Lonistic Site