TagEcology(788)

This August 2001 draft document outlines Water Quality Certification conditions (#1996-4-02325) governing stormwater management at Seattle-Tacoma International Airport (Sea-Tac). It sets requirements for the Port of Seattle to implement and maintain a Comprehensive Stormwater Management Plan, including retrofitting existing impervious surfaces, meeting state water quality standards, and obtaining Ecology approval before discharging stormwater to receiving waters. The document also addresses scheduling, flow control benchmarks, and the use of all known available and reasonable treatment methods (AKART) for runoff from impervious surfaces.

In August 2001, King County's Department of Natural Resources submitted a technical review letter to the Washington Department of Ecology evaluating the Port of Seattle's Low Flow Impact Analysis and proposed offset facilities for stormwater management near Sea-Tac Airport. The review found the proposal goes well beyond the basic requirements of the King County Surface Water Design Manual and represents substantial mitigation for low flow impacts in affected drainage basins, including Miller and Walker Creeks. Reviewers noted several inconsistencies and data gaps in the documentation and recommended that a final consolidated document be prepared incorporating all corrections and technical memoranda.

This August 2001 draft document outlines Water Quality Certification conditions for Sea-Tac International Airport (STIA), requiring the Port of Seattle to implement a Comprehensive Stormwater Management Plan covering treatment, flow control, and retrofitting of stormwater facilities. Key requirements include obtaining Ecology approval before discharging operational stormwater to state waters, conducting a Water Effects Ratio Study, and ensuring all runoff from impervious surfaces is treated using all known available and reasonable treatment methods. The Port must also retrofit existing stormwater facilities at a rate proportional to new impervious surface construction, with progress documented in quarterly reports.

In August 2001, King County's Department of Natural Resources wrote to the Washington Department of Ecology confirming that the Port of Seattle's Comprehensive Stormwater Management Plan for Sea-Tac International Airport Master Plan improvements met the technical requirements of the 1998 King County Surface Water Design Manual. The review found that the plan demonstrated a feasible conceptual strategy for managing stormwater from proposed airport construction projects. Reviewers noted that while the plan showed compliance with design standards, additional oversight and monitoring would be needed as individual projects moved from planning into construction.

Deliberative memorandum dated August 3, 2001 from Katie Walter (Shannon & Wilson, Inc.) to Ann Kenny (Washington State Department of Ecology), transmitting revised draft 401 conditions for the Port Of Seattle Natural Resources Mitigation Plan (NRMP) Auburn Mitigation Site. Document 21-1-12020-001-M1 REVISED.doc covers Auburn Mitigation Site revisions including culvert placement issues on June 28, 2001

Letter dated August 3, 2001 from King County Department of Natural Resources Director Pam Bissonnette to Ann Kenny, Senior Permit Specialist, Washington Department of Ecology Northwest Regional Office, transmitting King County’s technical review comments on the Port Of Seattle’s Low Flow Impact Analysis – Low Flow Impact Offset Facility Proposal (July 2001). The enclosure provides

Email dated August 3, 2001 from Katie Walter (KLW@shanwil.com) to Ann Kenny, cc Erik Stockdale, regarding fish and stream monitoring recommendations for Port Of Seattle mitigation area. Discusses IBI (Index of Biotic Integrity) methodology limitations and augmentation with monitoring of temperature, turbidity, channel morphology, substrate quality, large woody debris, riparian canopy cover, and fish use.

Letter dated August 3, 2001 from Pam Bissonnette, Director of King County Department of Natural Resources, to Ann Kenny, Senior Permit Specialist at Washington Department of Ecology Northwest Regional Office, conveying King County’s technical review findings on the Port Of Seattle’s Comprehensive Stormwater Management Plan (SMP) for Master Plan Update (MPU) Improvements at Seattle-Tacoma International

Email chain between John Drabek and Ann Kenny (Washington State Department of Ecology) dated August 3, 2001, regarding a preliminary deliberative draft Section 401 Water Quality Certification (WQC) for the Sea-Tac Airport Third Runway. Drabek raises question about RCW 90.48 required AKART implementation in NPDES permit reissuances and integration with the 401. Kenny’s original email

In this August 3, 2001 email, Andrea Grad, a paralegal at Helsell Fetterman, submits a Public Disclosure Act (PDA) request to Ann Kenny at the Washington State Department of Ecology. Grad notes that several sections of the Port of Seattle's two-volume Low Flow Analysis — including the Introduction and the section on Determination of Impacts to Streamflow — were either incomplete or entirely missing from the copy provided by Ecology. She asks Ecology to confirm whether the Port had submitted the missing sections, and requests copies of any such materials.