TagDes Moines Creek(162)

This draft memorandum from Parametrix (dated April 20, 1999) summarizes range-finding toxicity tests conducted as part of a water-effect ratio (WER) study examining copper levels in streams receiving stormwater runoff from Seattle-Tacoma International Airport (STIA). Water samples were collected from Miller Creek, Walker Creek, and Des Moines Creek during a storm event in February 1999 and tested using the organism Ceriodaphnia dubia to measure copper toxicity. Results showed water effect ratios ranging from 6.7 to 16.0, leading researchers to recommend pursuing a definitive WER study and a site-specific water quality standard for copper.

Memorandum from Ken Ludwa of Parametrix, Inc. to Elizabeth Leavitt, dated June 29, 1999, reviewing the Draft De-Icing Dissolved Oxygen Report related to Sea-Tac Airport runway and taxiway acetate washoff. Comments address dissolved oxygen (DO) water quality standards (8 mg/L Class A, 9.5 mg/L Class AA) in Miller Creek and Des Moines Creek, NW Ponds,

This 1999 email exchange between Washington State Department of Ecology staff debates the legal basis for requiring the Port of Seattle to restore water quality in Des Moines Creek as a condition of receiving a Section 401 water quality certification for the Sea-Tac Airport third runway project. The central question is whether Ecology can require a single applicant to fix broader watershed problems that pre-exist their project, or whether mitigation can only address the applicant's direct project impacts. Staff ultimately conclude that under antidegradation requirements, no further degradation of the creek can be permitted until existing beneficial uses are restored, meaning the Port's mitigation plan must include measures such as flow augmentation and stormwater controls to bring the creek into compliance with water quality standards.

Email chain (AR 033708–033710) among Washington State Department of Ecology staff Paula Ehlers, Tom Luster, and Raymond Hellwig, with ATG staff Tom McDonald and Joan Marchioro, dated June 1–13, 1999, regarding the Port Of Seattle third runway proposal and 401 water quality certification for Des Moines Creek. Discusses antidegradation requirements under Washington Water Quality Standards

A 1999 internal email from Ken Ludwa to airport staff reports that upstream water quality data for Miller Creek and Des Moines Creek shows both streams exceed copper concentration standards, meaning neither is currently in compliance. The analysis suggests that applying a Water Effect Ratio (WER) adjustment of 2 or more for Des Moines Creek and 4 or more for Miller Creek could bring the streams into apparent compliance with water quality standards. The email also raises the possibility of conducting new clean sampling to potentially replace the existing non-compliant data.

Email forwarded by Erik Stockdale to Tom Luster, originating from Gail Terzi, regarding SR509 proposal conflicts with Sea-Tac Airport third runway (SASA). Key issues include wetland fills in overlapping areas, moving Des Moines Creek for SR509 while Port Of Seattle spends millions bridging the creek at Tyee, and FAA telling WSDOT they CAN mitigate habitat

BioAnalysts, Inc. report by T.W. Hillman, J.R. Stevenson, and D.J. Snyder prepared for Airport Communities Coalition (ACC), Des Moines, WA. Surveys of habitat composition and condition, redd (nest) abundance and distribution, and spawning population characteristics of coho (Oncorhynchus kisutch), chum (O. keta), and cutthroat trout (O. clarki) in Miller Creek, Walker Creek, and Des Moines

Draft report (AR 041921) prepared by Parametrix, Inc. for Port Of Seattle, STIA, summarizing procedures and results of acute screening-level Ceriodaphnia dubia bioassays conducted on site water from Seattle-Tacoma International Airport in January 1999. Samples collected January 14, 1999 during a storm event at eight locations including Miller Creek Upstream of Lake Reba, Miller Creek

Hart Crowser memorandum (J-4978-03) dated December 23, 1998, from Michael Bailey P.E. and Michael Kenrick P.E. to Barbara Hinkle, Port Of Seattle, addressing hydrologic impacts of Borrow Areas 1, 3, and 4 for the Third Runway Project at Seattle-Tacoma International Airport. Discusses impacts on baseflow to Des Moines Creek and riparian wetlands, including runoff reduction,

Draft Des Moines Creek Flow Augmentation Plan prepared by Parametrix, Inc. for Port Of Seattle, dated August 18, 1998, AR 041729. Document covers proposed design for flow augmentation of Des Moines Creek using existing wells, well upgrades, conveyance system, and stream discharge at Seattle-Tacoma International Airport (Sea-Tac Airport) Master Plan Update Improvements. Includes operational criteria,