Airport Snow and Ice Responsibility
SEA Airport is responsible for snow and ice maintenance of runways, taxiways and the ramp areas (in and around the gates and cargo areas). In addition, the airport is responsible for clearing the terminal area, parking garage, Starling Road, Air Cargo Road to the Employee Parking Lot and the Airport Expressway just north of the return-to-terminal loop. During heavy snowfalls, of approximately three inches or more and accumulating, the Port of Seattle hires local contractors for additional snow removal.
Note: Each airline is responsible for de-icing its aircraft.
Anti-ice Fluid
The airport uses biodegradable potassium acetate as a liquid runway anti-icer. A solid runway deicer, sodium acetate, also is used at lower temperatures. On-site tanks store 75,000 gallons of anti-icing fluid (stored near north Cargo areas). During the last few years, SEA used about 36,000 gallons per winter season. De-icing fluid is restocked through a local distributor and ordered when necessary to keep on-site supplies at acceptable levels.
Note: This fluid cannot be used to de-ice aircraft. Airlines use various forms of glycol.
- Average fluid used per season: 36,000 gallons
- Total anti-icing fluid used 2008-2009 season: over 120,000 gallons
Equipment on Hand
SEA Airport has more than 45 pieces of equipment on hand for snow and ice maintenance including:
- Nine plow and broom combination units — state-of-the-art trucks with a 24-foot plow that’s as long as a semi
- Two friction testers to measure stopping distance for the runways
- Six sander/plows
- Seven high-speed plows
- Four de-icing trucks for Runways/Taxiways and Ramp areas [three 75’ wide booms, one 50’ boom-less]
- Additional sander, plow and chemical trucks dedicated for landside maintenance
- Pickup trucks with sanders and plows
- Seven high-speed plows
- Five snow blowers
- Six high-speed brooms
- Walk-behind snow blowers
- Lots of snow shovels and brooms and team members ready to work
Additional Supplies On-hand
300 tons of roadside sand, 350 tons of runway sand, 70 tons of dry chemical (used with sand)
Treatment Procedures
Anti-icing occurs prior to snowfall when temperatures reach 33-34 degrees. Anti-icing fluid works to stop ice from bonding to the concrete. The runways have embedded temperature monitors that allow staff to apply anti-icing fluid when necessary and conserve the supply.
Snow Removal on the Runways
Snow removal on the runways takes place with several snow plows stretched out at an angle with snow brooms following. It takes approximately 30 minutes to plow one runway.
Workforce: A normal season budgets 4,000 hours for snow removal.
Largest Recent Snowfall
- 2008 - 2009 Snowfall: Overall 23.3” fell during the winter (SEA average snowfall is 12”)
- 2019, February, 20.2”
Response Levels
The following alert levels are used to classify winter weather events at SEA.
Snow Watch
Approximately 24 hours prior to the forecasted start of snow or icing conditions at SEA, or when the snow level in the greater Seattle area is between 600 and 1000 feet, a Snow Watch may be declared by the Airport Duty Manager.
Snow Warning
Approximately 24 hours prior to the forecasted start of snow or icing conditions at SEA, or when the snow level in the greater Seattle area is below 600 feet, a Snow Warning may be declared by the Airport Duty Manager.
Snow Advisory
Approximately 8 hours prior to the forecasted start of a snow or ice event of 2” of snow or less in a 24-hour period, freezing rain/drizzle (less than ¼”), or as otherwise determined by the Senior Manager, Airport Operations. Snow Advisory will be declared by Airport Operations Manager or designee.
Snow Alert
At any time if forecasted accumulation of snow is greater than 3” in a 24 hr period, freezing rain warning (1/4” or more), or as otherwise determined by the Senior Manager, Airport Operations
Snow Demobilization
At any time after a snow event where snow removal has taken place, Snow Demobilization will be declared by the contacted Airport Operations Manager or designee. SCC will reduce to a modified staffing level and Ramp Cleanup will continue until areas return to normal operations.
Snow Control Center
The Snow Control Center is a central management facility for all airport snow and ice control activities. Snow Control Center assists in facilitating increased communications and decision processes associated with a larger snow and ice event.
