Antifreeze Poored into Washer Fluid Tank

Well someone poored some antifreeze into the washer fluid tank..... Not me. The owner of the car does not use the washer fluid yet he has to fill the washer fluid as if it has been in use. Its either one of two things
A) The washer fluid tank has a leak
B) The fluid is being used automatically by the car


If the fluid is being used automatically by the car than I just want to know if there would be damage if antifreeze comes into play.

Does anyone know of a way I can pump the antifreeze out? Thats what I might end up doing.

could u remove the washer fluid tank???

or perhaps syphon it with a long length of hose