15 St. Patrick's Day trivia questions to try while drinking a green beer
Chicago
As far back as 1962, Chicago has been known for its glowing green river in March. The dye is produced by the Chicago Plumbers' Union, and they pour 40 pounds of it into the river!
The dye usually filters out fo the water within a day or two, and the CPU assures citizens that there is no danger the humans, animals, or the environment thanks to their specialized formula. Some other cities try to mimic the effect, but none have managed to be quite as effective as the Chicago team.