TagStormwater(373)

Letter dated July 31, 2001 from Keith R. Smith, Water Resources Manager at Port Of Seattle, to Ms. Ann E. Kenny at the Washington State Department of Ecology Northwest Regional Office (Bellevue, WA 98008-5452), transmitting conceptual drawings for the proposed Flow Impact Offset Facility at Seattle-Tacoma International Airport. Drawings relate to reserved stormwater release storage,

Email from Ann Kenny (Washington State Department of Ecology, Northwest Regional Office) dated July 29, 2001, transmitting a preliminary draft 401 Water Quality Certification (WQC) for the Port of Seattle Third Runway construction at Seattle-Tacoma International Airport (STIA). Recipients include Raymond Hellwig, Kevin Fitzpatrick, John Drabek, Ching-Pi Wang, Erik Stockdale, Joan Marchioro (ATG), Tom Young

Deliberative internal email chain dated July 27, 2001 from Erik Stockdale to Ann Kenny, forwarded to Katie Walter, transmitting draft language for additional mitigation on Miller Creek related to the SeaTac 3rd Runway project (AR 018239–018241). The draft document, titled ‘Mitigation for Temporary Impacts — SeaTac 3rd Runway,’ addresses Ecology’s determination that impacts characterized as

Letter dated July 23, 2001 from Port Of Seattle to Ann E. Kenny at Washington State Department of Ecology Northwest Regional Office regarding Low Streamflow Analysis and Summer Low Flow Impact Offset Facility Proposal for Seattle-Tacoma International Airport. Covers summer low streamflow impacts in Des Moines Creek, Miller Creek, and Walker Creek from airport Master

Port of Seattle letter dated July 23, 2001 to Ann E. Kenny, Washington State Department of Ecology, Northwest Regional Office, summarizing low streamflow impact analysis and flow impact offset facility proposal for Seattle-Tacoma International Airport Master Plan Update projects. Prepared by Parametrix, Inc. Analysis covers summer low streamflow impacts to Des Moines Creek, Miller Creek,

Parametrix, Inc. report prepared for Port Of Seattle assessing the existing (1994) and future (2006) hydrologic divide of Miller Creek, Walker Creek, and Des Moines Creek following Master Plan Update (MPU) construction at Seattle-Tacoma International Airport (STIA). Analyzes compliance with Governor’s Certification requirement that the third runway project will not cause changes in the location

A water resources consultant raised concerns in a July 2001 letter to the U.S. Army Corps of Engineers and Washington State Department of Ecology about the Port of Seattle's stormwater management plans for Sea-Tac Airport expansion. The letter challenged the effectiveness of proposed biofiltration swales, noting they can actually increase bacterial levels rather than reduce them, and warned that releasing stored stormwater from detention vaults into nearby Class AA streams could discharge pollutant-laden, oxygen-depleted water into already stressed waterways. The consultant concluded that the Port's plans fell short of providing reasonable assurance that water quality standards would be met.

In a July 18, 2001 memo to Governor Gary Locke, Washington State Department of Ecology Director Tom Fitzsimmons provided an update on the permitting process for the Port of Seattle's proposed Third Runway at Sea-Tac Airport. The department was awaiting final technical data from the Port on stream low-flow mitigation, expected by July 23, 2001, before issuing a 401 Water Quality Certification decision. Provided the information was satisfactory, Ecology planned to render a final decision on the runway project during the week of August 6, 2001.

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.

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.