Chicago has been pouring dye into the river for over sixty years. Originally, 100 pounds of dye was dumped in the river in order to clean up the waterfront areas. The dye left the river green for an entire week. Today, the river is dyed with 40 pounds of environmentally-friendly dye, which is vegetable based and actually is orange in color. Two motor boats are used to color the river emerald green. One boat dumps the powder and the other boat acts to stir it. The dye typically lasts four to five hours, but can last up to 24-48 hours.
Dyeing of the river has become a Chicago tradition and is dyed in coordination with the Chicago St. Patrick’s Day parade.

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