TagPort Of Seattle(2405)

Hart Crowser draft subsurface conditions data report (project J-4978-18) prepared for Port Of Seattle and HNTB, dated March 20, 2000, covering the North Safety Area Third Runway Embankment at Sea-Tac International Airport. Report includes generalized geologic description, subsurface soil conditions, hydrogeologic conditions, laboratory test results (consolidation, CU triaxial, UU triaxial, direct shear tests), hydraulic conductivity

A March 2000 Parametrix memorandum reports the results of pesticide and herbicide soil testing at the Vacca Farm site, part of the Port of Seattle's Third Runway Project. Of 59 compounds tested, only 12 were detected, primarily organochlorine pesticides, with Dieldrin slightly exceeding cleanup levels in shallow soil samples at two locations in the proposed floodplain area. The memo recommends removing the upper six inches of soil from the floodplain area for offsite disposal, while concluding that the proposed Miller Creek relocation corridor does not pose unacceptable risks to human health.

SEPA Addendum (April 27, 2000) prepared by Port Of Seattle and FAA as addendum to the Final Supplemental Environmental Impact Statement for the Proposed Master Plan Update Development Actions at Seattle-Tacoma International Airport (STIA), and to the SEPA Environmental Checklist for the Auburn Wetland Mitigation Project (August 1998). Documents modification to Master Plan Update wetland

A February 2000 draft memo from environmental consultants Parametrix summarizes testing and monitoring data concluding that stormwater runoff from Seattle-Tacoma International Airport (STIA) does not harm aquatic life in nearby Miller and Des Moines Creeks. Three lines of evidence are presented: whole effluent toxicity tests showing most outfalls are non-toxic, water effect ratio studies demonstrating that creek water significantly reduces copper toxicity, and metals monitoring confirming that copper concentrations in the creeks fell below water quality standards. The one outfall found to be toxic (SDN1) was traced to zinc leaching from galvanized rooftops, with the Port of Seattle pursuing corrective measures.

A February 2000 draft memorandum from Parametrix, Inc. outlines a scope and budget for range-finding Water-Effect Ratio (WER) studies using receiving water from Miller and Des Moines Creeks, conducted in connection with stormwater discharge permitting near the Port. The studies involve acute toxicity tests with copper-spiked water to determine whether site-specific water quality standards could be higher than generic state standards, potentially eliminating the need for a mixing zone. Estimated costs range from $2,110 for one creek site to $2,650 for two sites.

A February 2000 draft memorandum from Parametrix, Inc. outlines a scope and budget for range-finding Water-Effect Ratio (WER) studies using receiving water from Miller and Des Moines Creeks, intended to help determine whether copper discharge standards at a Port facility could be adjusted through site-specific water quality criteria. The studies involve acute toxicity tests comparing copper-spiked site water to copper-spiked laboratory water, with estimated costs ranging from $2,110 for one site to $2,650 for two sites. Results from earlier 1999 range-finding tests suggested WERs high enough to potentially justify more definitive studies, but new tests without mixing zone assumptions were recommended to better assess achievable permit limits.

A February 2000 internal draft memorandum from environmental consultants to Port of Seattle staff summarizes efforts to develop a site-specific water quality criterion for copper in Miller, Walker, and Des Moines Creeks, in connection with stormwater runoff anticipated from a proposed third runway at Sea-Tac Airport. The memo evaluates two technical approaches—the Water-Effect Ratio (WER) and the site-specific metals translator—for potentially raising copper discharge permit limits, and outlines initial toxicity screening and range-finding study results. It also describes ongoing negotiations with the Washington State Department of Ecology regarding unresolved issues such as mixing zones, AKART requirements, and critical sampling conditions.

Email chain dated February 8, 2000 among Washington State Department of Ecology staff (Roger Nye, Raymond Hellwig, Steve Alexander) regarding fill criteria compliance for the Third Runway at Sea-Tac Airport. Roger Nye describes the 401/404 permit fill acceptance policy developed with Port Of Seattle governing contaminant criteria for borrow sources used in Third Runway construction

Letter dated February 1, 2000 from John Strunk, Associated Earth Sciences, Inc. (AESI Project No. BV97016D) to Roger Nye, Washington Department of Ecology Northwest Regional Office, submitting first and second quarter ground water level measurements from the C1 (Qva) aquifer monitoring well network at Seattle-Tacoma International Airport. Reports on six pressure transducers installed in the

Memorandum BV97016D dated January 31, 2000, from John Strunk (Associated Earth Sciences Inc.) and Mike Riley (S.S. Papadopulos & Associates, Inc.) to Roger Nye, Department of Ecology, responding to nine Ecology comments on the Conceptual Flow Model Boundary Presentation for the Seattle-Tacoma International Airport ground water study. Topics addressed include MODFLOW model setup covering approximately