By D. A. (Midwested) on Sunday, January 7, 2018 - 01:06 pm:
Alex,
Aircraft deicing uses propylene glycol antifreeze chemicals that would run directly into the lake. There are systems used on some ships that use mini-excavators or superheated water in power washers. My estimate is they are actually making a path (or trench if you will) so later warm water applied has a path to run off easily rather than refreezing.