De-Icing & Stormwater
Safe Flights, Responsible Runoff
What is the De-Icing & Stormwater Program?
Why De-Icing Matters
De-icing is vital for flight safety. Snow and ice buildup can disrupt the aerodynamics needed for safe takeoff. The FAA requires commercial carriers to provide timely application of de-icing fluid before departure to ensure aircraft can operate safely in freezing conditions.
How It Works at Spokane International Airport
- Application & Collection: Airlines de-ice their own aircraft. The Airport operates three glycol recovery vehicles (GRVs) that collect spent de-icing fluid from ramps and taxiways.
- Land Application Program: Since 2011, the Airport has worked with Ecology to test and implement a sustainable disposal process. Fluid and stormwater are collected, stored through winter, and applied to a land treatment site in spring. Soil microbes safely break down the compounds before they reach groundwater.
Regulatory Approval & Long-Term Benefits
After nine years of successful pilot testing, the Washington State Department of Ecology issued the Airport a permanent permit-by-rule in 2020. Monitoring showed no adverse effects—and even improvements—to groundwater quality.
See Letter of Support from Washington State Department of EcologyRead Letter ›
Regulatory Approval & Long-Term Benefits
- Reduces risk of groundwater contamination
- Minimizes pollutant loads in stormwater
- Avoids costly offsite treatment
- Preserves safety while meeting FAA and Ecology standards
FAQ
What is de-icing fluid made of?
De-icing fluid is a biodegradable compound made of propylene glycol and water.
Where does de-icing take place?
De-icing fluid has a holdover time, meaning that the solution’s effectiveness decreases as time goes on. For this reason, de-icing fluid is applied when a plane is ready for departure, either at the gate after pushback or at a designated de-icing pad on the ramp.
De-icing fluid is also sprayed onto public roadways as a preemptive measure to keep streets and freeways from ice and snow build up.
Who is responsible for de-icing?
Ensuring safety and efficiency, especially in winter weather conditions, takes a team!
Airlines are responsible for managing their own aircraft de-icing operations. This includes purchasing, storing and applying de-icing fluid to their planes, while the Airport maintains responsibility of keeping runways, taxiways and ramps clear of snow and ice.
The Airport also plays an important role in the safe disposal of spent de-icing fluid.
How much fluid is collected and where does it go?
A Glycol Recovery Vehicle (GRV) is a specialized vehicle that collects slush and water containing spent de-icing fluid from the Airport’s ramps, taxiways, runways and other areas…in other words, a really large airfield vacuum. The Airport currently owns and operations three GRVs, which each have the capacity to hold 1,000 – 2,000 gallons.
What is “land application” and is it safe?
Land application uses natural soil processes to break down de-icing compounds. After a multi-year pilot, Ecology confirmed the method improves groundwater quality.
Does de-icing fluid contain PFAS?
No. De-icing fluid is a biodegradable compound made of propylene glycol and water.
