TagACC(1534)

This document contains a September 2000 email exchange regarding the proposed expansion of Lagoon #3 in the Sea-Tac Airport Industrial Wastewater System (IWS), in which consultant Bill Rozeboom follows up on unresolved comments submitted to the Washington State Department of Ecology. The attached July 31, 2000 comments raise concerns about discrepancies in the lagoon's design capacity, the risk of frequent overflow into Des Moines Creek, and potential wildlife hazards near aircraft movement areas that may violate FAA guidelines. Additional issues flagged include incomplete construction plans, unaddressed lagoon deficiencies, and the apparent overlap of the lagoon expansion project with 3rd runway construction activities affecting nearby wetlands.

A biological assessments consultant, writing on behalf of the Airport Communities Coalition, critiques the Port of Seattle's revised plan to use City of Seattle drinking water to boost summer flows in Des Moines Creek near Sea-Tac Airport. The letter raises concerns that the plan inadequately addresses the toxicity of fluoride and residual chlorine in treated drinking water, which can harm fish and other aquatic life at very low levels. The consultant also warns that differences in temperature, pH, and dissolved oxygen between the makeup water and the creek could cause serious ecological damage if not corrected before augmentation begins.

Technical memorandum dated September 5, 2000 from Elizabeth Leavitt (Port Of Seattle) to Ray Helwig (Washington State Department of Ecology), cc’d to Erik Stockdale, Nancy Groves (Ecology), Jim Kelley and Paul Fendt (Parametrix), Project No. 556-2912-001(03). Addresses CWA Section 401 permit issues for Seattle-Tacoma International Airport Master Plan Update projects involving wetlands and streams. Topics

Draft subsurface conditions data report prepared by HartCrowser for HNTB regarding the Third Runway Embankment at Sea-Tac International Airport, project numbers J-4978-23, -26, -27, and -31. Covers additional field explorations and advanced geotechnical testing including auger borings, standard penetration tests (SPT), Shelby tubes, pocket penetrometer, test pits, piezocone penetrometer probes, cone penetration tests (CPT), and

This September 2000 preliminary design report, prepared by Kennedy/Jenks Consultants for the Port of Seattle, outlines a plan to augment water flow in Des Moines Creek near Seattle-Tacoma International Airport. The report covers facility configuration, process components such as backflow prevention, dechlorination, and aeration systems, as well as an evaluation of chemical dechlorination alternatives. The project was designed to improve creek water quality by treating and releasing water in a controlled manner.

A September 2000 report by Azous Environmental Sciences, commissioned by the Airport Communities Coalition, critically analyzes the Port of Seattle's wetland mitigation plan for the SeaTac Third Runway construction project. The report identifies numerous errors in wetland acreage accounting, inadequate mitigation ratios, and flaws in the proposed compensatory measures, including out-of-basin mitigation that fails to replace lost wetland functions in the affected Miller, Walker, and Des Moines Creek watersheds. The author concludes that the Port's plan falls short of Washington State Department of Ecology standards and the regulatory goal of no net loss of wetland functions.

Reinforced Earth Company (job number 8079, designer MJB, dated 09/01/00) design calculations for Port Of Seattle Sea-Tac International Airport, West Wall 181+25. Document covers internal and external stability analysis for a Mechanically Stabilized Earth (MSE) retaining wall structure including design parameters (select backfill φ=37°, γ=0.140 kcf, Ka=0.24858; random backfill φ=35°, γ=0.140 kcf, Ka=0.27269; foundation φ=35°,

AR017487. Email from Chung K. Yee (Ecology, NWRO Water Quality Program) to Kevin Fitzpatrick dated August 24, 2000, commenting on draft clean fill criteria language for the 401 Certification for the Third Runway at Sea-Tac Airport. Comments address sections E6, E7c.2.(b), E7c.2.(e), and E7c.3, covering inappropriate fill, EPA databases, Confirmed & Suspected Contaminated Sites Report,

Internal email chain from Chung K. Yee to Kevin Fitzpatrick (Supervisor, Industrial Permit Unit, Water Quality Program, NWRO, Washington Department of Ecology) dated August 24, 2000, commenting on draft clean fill criteria language for the 401 Certification for the Third Runway at Sea-Tac Airport. Comments address sections E6, E7c.2(b), E7c.2(e), E7c.2(f), and E7c.3, covering issues

A fisheries biologist assessed the Port of Seattle's plan to use City of Seattle drinking water to boost summer flows in Miller and Des Moines Creeks when levels drop below 1.0 cubic feet per second. The report concludes that chlorine and fluoride in drinking water are toxic to fish and other aquatic life at very low concentrations, and that mixing drinking water into these small streams would far exceed Washington State water quality standards even with dilution. The biologist recommended against the plan and suggested that treated well water from within the local watersheds might be a less harmful alternative.