TagStormwater(385)

Final draft meeting notes from October 2, 2000 (9:00–4:00) for Sea-Tac Airport Third Runway 401 Permit Negotiations, prepared by Kate Snider of Floyd & Snider Inc. Attendees include representatives from Washington State Department of Ecology (Ray Hellwig, Kevin Fitzpatrick, Tom Luster), Port Of Seattle (Michael Cheyne, Elizabeth Leavitt, Keith Smith, Jim Thompson), King County (Kelly

Letter dated September 28, 2000 from Tom Fitzsimmons, Director of Washington State Department of Ecology, to M.R. (Mic) Dinsmore, Executive Director of Port Of Seattle, responding to Port Of Seattle’s withdrawal of its Clean Water Act § 401 Water Quality Certification application for the Third Runway project at Seattle-Tacoma International Airport. Ecology outlines conditions for

Annual stormwater monitoring report prepared by Scott Tobiason, Environmental Management Specialist, Aviation Environmental Programs, Port Of Seattle, covering Sea-Tac Airport (STIA) for the period July 1, 1999 through June 30, 2000. Report covers STIA storm drainage subbasins, sampling locations, grab and composite sample results for total petroleum hydrocarbons (TPH), fecal coliforms, suspended solids, turbidity, biochemical

Annual Stormwater Monitoring Report for Seattle-Tacoma International Airport (STIA) covering the period July 1, 1999 through June 30, 2000, prepared by Scott Tobiason, Environmental Management Specialist, Aviation Environmental Programs, Port Of Seattle. Report AR 045668 documents stormwater sampling results from STIA storm drainage subbasins including total petroleum hydrocarbons (TPH), fecal coliforms, suspended solids, turbidity, biochemical

A September 2000 letter to the Washington State Department of Ecology raises concerns about the Stormwater Management Plan for Seattle-Tacoma International Airport's third runway expansion, arguing it fails to demonstrate compliance with the Governor's Certification requirement to avoid altering water flow between Miller and Des Moines Creeks. The letter also challenges the feasibility of proposed improvements to the airport's Industrial Wastewater System, citing inadequate modeling, unresolved capacity issues, and potential conflicts with FAA safety guidelines regarding wildlife attractants near runways.

A September 2000 letter from Northwest Hydraulic Consultants raises concerns about the Stormwater Management Plan for Seattle-Tacoma International Airport's third runway expansion, finding that it fails to demonstrate compliance with the Governor's Certification requirement to protect water flow in Miller and Des Moines Creeks. The letter also identifies serious problems with the airport's plan to manage stormwater through expansions to its Industrial Wastewater System, including unresolved engineering uncertainties and potential conflicts with FAA wildlife safety guidelines that prohibit wastewater facilities within 10,000 feet of runway areas.

A September 2000 letter from Northwest Hydraulic Consultants raises concerns that the Seattle-Tacoma International Airport's Stormwater Management Plan fails to adequately assess or mitigate the third runway embankment's impact on stream base flows and seepage flows to nearby wetlands. The consultants argue that the Port of Seattle's own data contradicts its claims that the embankment fill would maintain groundwater recharge, and that independent re-analysis suggests summer groundwater reductions to Miller Creek could be roughly twice what the Port reported. The letter calls for more rigorous and consistent hydrologic modeling before construction commitments are made.

This September 2000 letter from environmental reviewers raises concerns about the Seattle-Tacoma International Airport third runway expansion project, specifically arguing that the Port of Seattle's Stormwater Management Plan fails to adequately assess or mitigate reductions in stream base flows and seepage flows to nearby wetlands. The reviewers present hydrological modeling data suggesting that groundwater inputs to Miller Creek could be reduced significantly more than the Port's own estimates indicate, and that the fill embankment's actual drainage behavior contradicts the Port's claims that it would function like natural outwash soil. The letter challenges the Port's assurances that seepage flows to downstream wetlands would be preserved, citing conflicting data within the Port's own documents and questioning the reliability of the analyses used to support those claims.

A September 2000 letter from Northwest Hydraulic Consultants, written on behalf of the Airport Communities Coalition, raises serious technical concerns about the Stormwater Management Plan for Seattle-Tacoma International Airport's proposed third runway. The letter highlights findings from King County reviewers showing that multiple stormwater facilities in the plan were unverified, potentially infeasible, or unlikely to meet required flow control performance standards. The consultants argue that the review timeline was insufficient and that the Port of Seattle had a history of failing to deliver promised stormwater mitigation measures.

In September 2000, Northwest Hydraulic Consultants submitted preliminary technical comments on behalf of the Airport Communities Coalition, raising serious concerns about the adequacy of the Stormwater Management Plan for Seattle-Tacoma International Airport's proposed third runway expansion. The letter highlights findings from King County's independent review, which identified numerous cases where proposed stormwater control facilities were unverified, infeasible, or unlikely to meet required flow control performance standards. The consultants warned that the compressed public review timeline was insufficient for thorough evaluation of the plan before Ecology's 401 Certification decision.