The calls are almost always from people who live under one of the main flight paths into Chicago O'Hare International Airport or Chicago's Midway Airport . This Web Page has been created to assist you in determining if Blue Ice, Blue Water or some other substance has fallen on your property. Many people are of the assumption that aircraft lavatories dump overboard when they are flushed, this is not the case.
Lavatory waste is contained on the aircraft in a holding tank until the aircraft lands.
When the aircraft is safely on the ground, only ground crew personnel may operate the valve to dump the waste tank. While in flight it is physically impossible for the pilots to dump the waste water because the valve is usually located on the exterior of the aircraft. One possible explanation that we receive more calls in the autumn is that birds, particularly Canadian Geese, are starting to flock together and prepare for their migration south. Another important thing to remember is that a lot of different fruit trees are ripening at this time of year and that is what the birds will eat. As the fruit goes through the bird's digestive system it loses none of its color.