We are leading the design of an expanded wastewater treatment system at Seattle-Tacoma International Airport (SEA) to improve environmental performance and operational efficiency.
The project achieves 30 percent design in early 2026. When operational, it will introduce an aerated gravel bed biological treatment system to remove de-icing fluid from stormwater, enabling most industrial waste from the airfield to be safely discharged into local water bodies rather than the municipal sewer system.
This approach will significantly reduce the airport’s reliance on external treatment facilities and support sustainable water management.
Key sustainability benefits
- Natural process: biological treatment for de-icing fluid reduces chemical load and improves water quality before discharge.
- Flow equalization and storage: a 5-million-gallon tank ensures controlled treatment and minimizes environmental impact.
- Infrastructure modernization: replacement of the existing dissolved air flotation system with advanced technology is tailored for current needs.
- Integrated design across disciplines: structural, civil, electrical, instrumentation and control, architectural and landscape elements work together for efficiency and resilience.
- Energy and resource optimization: new blower building, chemical dosing facility and operator control space improve operational control and reduce energy waste.