Maybe not happening anymore but I read an article in a magazine about Piper Pawnees being used to de-ice the runways in the Chicago area(including O'Hare Airport) in 1970. The article included a picture of one of the aircraft at the airport.

Very little on the internet about it but I did find this brief mention about it on the right side just above the picture of the Beech 99.

https://www.flightglobal.com/pdfarchive ... r%20pawnee

It is called Dew De-icing for some reason.

Interesting that they would use an aircraft to disperse Urea, the same stuff we use today I would imagine.