This report examines how Seattle-Tacoma International Airport has affected nearby surface water quality from 1997 to 2019, focusing on streams, wetlands, and stormwater systems that receive runoff from airport property. Researchers analyzed water quality data from multiple airport drainage outfalls — measuring pollutants such as copper, zinc, glycols, and turbidity — using records submitted to Washington State environmental regulators. The study also tracks how major airport developments, including the construction of a third runway, have influenced local waterways like Miller Creek, Walker Creek, and Des Moines Creek.Open full document
Notes
This section of a 2020 study reviews changes in surface water quality at and around Sea-Tac Airport from 1997 to 2019, including analysis of the airport’s NPDES stormwater outfalls and water quality data. It examines the effects of airport operations and developments—particularly the construction of a third runway—on nearby streams and wetlands including Miller, Walker, and Des Moines creeks. Water quality data was sourced from Washington Department of Ecology’s PARIS database and covers parameters such as copper, zinc, turbidity, pH, and biochemical oxygen demand.