TagMiller Creek(260)

A December 1999 environmental assessment prepared for Citizens Against Seatac Expansion (CASE) concludes that the Port of Seattle failed to provide sufficient scientific evidence to assure compliance with Clean Water Act water quality standards for its Seattle-Tacoma International Airport expansion project. The report found that stormwater runoff from the airport was causing ongoing violations of toxic substances criteria — particularly for copper and zinc — in nearby Miller and Des Moines Creeks, with pollutant levels sometimes exceeding EPA limits by more than tenfold. The author argues that Ecology therefore lacked a scientifically defensible basis to issue a Section 401 water quality certification for the proposed wetland-filling and stormwater management improvements.

A November 1999 technical letter from Northwest Hydraulic Consultants, submitted on behalf of the Airport Communities Coalition, identifies major deficiencies in the proposed stormwater management plan for Seattle-Tacoma International Airport's 3rd runway development. The review finds that the plan fails to comply with the 1998 King County Surface Water Design Manual and Washington State Department of Ecology guidelines, including requirements for large-site drainage reviews, offsite analysis, and flow control. The consultants warn that if the plan is approved as written, it could cause significant adverse impacts to downstream creek systems, including Miller Creek and Des Moines Creek.

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.

Parametrix, Inc. summary (August 11, 1999) of key wetland findings from the Sea-Tac Runway Fill Hydrologic Studies Report (Pacific Groundwater Group 2000), prepared for the Port Of Seattle Master Plan Update Improvements JARPA review. Covers wetland delineation conservatism, limiting habitat characteristics of Miller Creek, Walker Creek, and Des Moines Creek, salmonid habitat significance, indirect embankment

A 1999 memo from the Washington State Department of Ecology evaluates construction techniques for a retaining wall near Miller Creek at Sea-Tac International Airport's Third Runway project. The memo concludes that specialized methods such as tied-back walls, bored piles, soil nailing, or ground freezing can address difficult underground soil conditions while keeping construction within the approved wetlands disturbance footprint, though at significant cost. The author also recommends installing monitoring devices in the wall and backfill to confirm the structure performs as designed throughout its service life.

Report AR042353 prepared by HNTB, Hart Crowser Inc., and Parametrix for Port Of Seattle Aviation Program Management Group, evaluating retaining wall and slope alternatives to reduce impacts to Miller Creek at embankment station 174+00 to 186+00 for the Third Dependent Runway project at Sea-Tac International Airport. Transmitted July 13, 1999 by Barbara Hinkle to Tom

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,

Technical memorandum prepared by HNTB Corporation for the Port of Seattle and Parametrix, Inc. (June 15, 1999) analyzing temporary wetland impacts during Seattle-Tacoma International Airport Third Runway embankment construction. AR 042490. Covers storm water management during construction, temporary fill in wetlands west of runway embankment toe, impacts to Wetland 37 (Miller Creek basin) and Wetland

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.

This 1999 document by C. Gower describes the Miller Creek Basin, a historic Puget Sound salmon stream located in the cities of SeaTac, Burien, and Normandy Park in King County, Washington (Water Resource Inventory Area No. 9). The basin includes several lakes — Arbor, Tub, Reba, Lora, and Burien — and drains into Puget Sound via Miller Creek and Walker Creek. The map highlights the proposed Third Runway site at Sea-Tac Airport within the watershed, raising concerns about potential environmental impacts to this salmon-bearing stream system.