TagMiller Creek(260)

Memorandum dated August 7, 2001 from Dave Garland, NWRO Water Quality Watershed Unit Supervisor, Washington State Department of Ecology, to Ann Kenny, Kevin Fitzpatrick, and Ray Hellwig, reviewing Parametrix Inc.’s July 2001 “Low Flow Analysis, Flow Impact Offset Facility Proposal” prepared for the Port Of Seattle regarding the proposed third runway at Sea-Tac Airport. Reviews

Memorandum dated August 7, 2001 from Dave Garland, NWRO Water Quality Watershed Unit Supervisor, to Ann Kenny, Kevin Fitzpatrick, and Ray Hellwig of the Washington State Department of Ecology Northwest Regional Office. Reviews the Parametrix Inc. July 2001 report ‘Low Flow Analysis, Flow Impact Offset Facility Proposal’ prepared for Port Of Seattle regarding predicted impacts

A technical review letter from Northwest Hydraulic Consultants, written on behalf of the Airport Communities Coalition, raises serious concerns about the Port of Seattle's Low Flow Analysis related to the proposed 3rd runway at SeaTac Airport. The letter identifies the July 23, 2001 document as incomplete and inconsistent with other project plans, citing missing sections, absent facility drawings, and unresolved questions about how water storage and release systems would function in practice. Key technical issues flagged include inadequate accounting for water transit losses, potentially impractical small-orifice flow controls, and poor calibration of streamflow models for Walker Creek.

Draft memorandum dated 8/6/01 from Ray Hellwig, Director, Washington State Department of Ecology, to Tom Fitzsimmons, Director, recommending approval of a 401 Water Quality Certification for the Port Of Seattle’s Sea-Tac International Airport Third Runway project. Document covers 8,500-foot parallel third runway, Runway Safety Areas (RSAs), South Aviation Support Area (SASA), impacts to approximately 700

A biological scientist hired by the Airport Communities Coalition reviewed the Port of Seattle's plan to store airport stormwater in detention vaults and release it into Miller, Walker, and Des Moines Creeks during summer low-flow periods. The review found that the plan could worsen water quality in those creeks, because stored sediments may release toxic levels of copper and zinc, and potentially harbor human pathogens from airplane wastewater. The scientist concluded that regulators lacked sufficient information to approve the proposal without further testing, modeling, and independent scientific review.

A water resources consultant, writing on behalf of the Airport Communities Coalition, argues that the Port of Seattle's July 2001 Low Flow Analysis for Sea-Tac Airport expansion fails to provide reasonable assurance that the project will meet water quality standards in Miller, Walker, and Des Moines Creeks. The letter criticizes the submission as incomplete and rushed, noting missing figures, unfinished sections, and an unresolved plan to store the required 46 acre-feet of stormwater across the three watersheds. The consultant contends that the Port's proposed water quality protections—including filtration, aeration, and biofiltration swales—are unproven, inadequately designed, and fall short of the regulatory standard required for Section 401/404 permit approval.

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

This August 2001 King County review evaluates the Port of Seattle's Low Flow Impact Analysis and proposed Flow Impact Offset Facility, which aims to mitigate reductions in stream flows in local creeks—including Des Moines, Miller, and Walker creeks—caused by future airport development. The review finds that while the proposed water storage and augmentation measures substantially offset low-flow impacts during the critical late-summer period, there are significant gaps in documentation, biological assessment, and design details that need to be addressed. Recommendations include professional engineering certification, enhanced biological monitoring, improved calibration documentation, and refinements to the reserve storage facility designs.

Deliberative memorandum dated August 1, 2001 from Katie Walter (KLW@shanwil.com) to Ann Kenny, Washington State Department of Ecology, re Draft 401 Conditions for Auburn Mitigation Site revisions. Covers culvert placement issues in revised grading plan (June 28, 2001) at northwest corner and south central portion of site, drainage swale, maintenance pathway, and southwestern basin. Performance

Deliberative memorandum dated August 1, 2001, from Katie Walter to Ann Kenny, Washington State Department of Ecology, re Draft 401 Conditions for the Auburn Mitigation Site. Covers culvert placement issues in the revised grading plan (June 28, 2001) including northwest corner drainage swale culvert (approximately 60 feet long), south central mis-located culvert, and two additional