You probably have noticed that The Highline Times has recently run a couple of articles about the Third Runway at Sea-Tac Airport, and how many of the airport neighbors in surrounding cities are feeling "duped" because we were told (promised) that the runway was to be used as an alternate to the existing two in inclement weather, and now, it is obvious that it is being used daily.
The Port has even admitted that it "will be used 365 days a year."
I personally also believe that they are using it for takeoffs as well.
Having spent over 20 years in the airline bus