TagWater Quality(53)

In November 1999, Highline Water District and the Port of Seattle reached a settlement agreement resolving competing claims over two water rights near Seattle-Tacoma International Airport. Under the deal, the Port retained rights to Well #1 for uses including Des Moines Creek flow augmentation tied to the proposed third runway project, while the District secured rights to a replacement for Well #2 to continue providing drinking water to its 58,000 customers. The District emphasized that the agreement was strictly about protecting its water rights and service area, and that it took no official position on the controversial third runway expansion.

The 1997 Des Moines Creek Basin Plan is a collaborative watershed management document produced by the City of SeaTac, City of Des Moines, Port of Seattle, and King County. It addresses stormwater, drainage, and environmental conditions within the Des Moines Creek basin, an area significantly influenced by Sea-Tac Airport and surrounding urban development. The plan establishes coordinated strategies among the four jurisdictions to manage water quality and flooding in this shared watershed.

This 1997 Annual Stormwater Monitoring Report, prepared by Scott Tobiason of Port of Seattle Environmental Services, documents water quality data collected from Seattle-Tacoma International Airport's stormwater discharges between July 1, 1996 and May 31, 1997. The report analyzes discharge samples from stormwater outfalls across the airport's drainage basins, comparing results to regional and national benchmarks, and notes that improvements from newly installed Best Management Practices (BMPs) would be evaluated in the following year's report. It was submitted to the Washington Department of Ecology in fulfillment of Special Condition S.9 of the airport's NPDES permit.

The 1994 Puget Sound Water Quality Management Plan is a regional environmental policy document adopted on May 18, 1994 by the Puget Sound Water Quality Authority, based in Olympia, Washington. It outlines strategies and guidelines for managing and protecting water quality across the Puget Sound region. Note: This document pertains to water quality management and does not contain content related to Sea-Tac Airport noise policy.

A 1993 Port of Seattle letter to Des Moines resident Barbara Stuhring explains that airplane deicing at Sea-Tac uses only FAA-approved ethylene or propylene glycol, and that wastewater from deicing drains to the airport's treatment system before being discharged to Puget Sound — not to Miller or Des Moines Creeks. A 1996 Final Environmental Impact Statement (EIS) later addressed public concerns about deicing fluid effects on local waterways, concluding that glycol quantities in stormwater runoff were too small and too diluted to cause lethal impacts on aquatic life in those creeks. Stuhring subsequently wrote to the Port challenging what she saw as a contradictory response in the Final EIS compared to the original 1993 letter.

This Washington State Department of Ecology report outlines stormwater erosion and sediment control requirements for large construction projects involving one or more acres of disturbed land in the Puget Sound Basin. It describes best management practices (BMPs) such as covering exposed soil, trapping sediment onsite, and protecting adjacent properties from runoff and sediment. Developers are required to create an erosion and sediment control plan and are financially responsible for its implementation.

A 1992 water quality study of Des Moines Creek, prepared by Parametrix, Inc. for the FAA and Port of Seattle, assessed the health of the creek during storm runoff events. The creek, which originates near Sea-Tac International Airport and flows to Puget Sound, had its aquatic ecosystem severely damaged by jet fuel spills in 1985 and 1986. The study sampled seven locations along the creek and three tributaries to identify water quality problems and determine whether stormwater pollution from airport operations was causing toxic conditions.