What turns the Chicago River Green?

March 17th, 201413217804355_6d96961318

If you are fortunate enough to be in Chicago on St. Patrick’s Day, you will become witness to many delightful sights, such as the annual St. Patty’s Day Parade, waves of green beer and people dressed as modern-looking leprechauns. One sight to behold is the Chicago River turning green.

Chicago goes all out for St. Patrick’s Day. Both locals and tourists come together in their green clothing at Michigan Avenue and Wacker Drive to witness the dying of the river followed by an impressive parade.


When living in Chicago, I had always wondered how it all got started and because of the color fit for emerald city, whether or not it was eco-friendly.

How it got started:
According to Chicago parade organizers, the tradition began when in 1961, a business manager for the plumber’s union named Stephen Bailey saw a plumber whose coveralls had been stained green. The stains had appeared thanks to a special dye used to detect leaks. 1961 was also the year that the city had begun enforcing pollution controls and the plumber was using a dye to locate the source of illegal waste disposal in the Chicago River. Mr. Bailey then had an idea. He contacted city officials and dumped 100 pounds of a disodium salt called fluorescein into the river. It was so powerful it turned the river green for a week. Nowadays, it is only green for a day.

The Formula:
Since fluorescein can prove to be a toxic substance, environmentalists became obviously very concerned about the welfare of the river and the creatures inside it so they lobbied to do away with the fluorescein and instead dye the river using an eco-friendly vegetable dye.

Although city officials claim that the dye is safe, it is unclear because the formula is a heavily guarded secret. The parade committee once compared the formula to that of Coca Cola. That statement indeed raised some eyebrows but the secret ingredients remain to be known. Perhaps someday with the luck of the Irish, we will find out what turns the Chicago River green and whether or not it is eco-friendly.

-Monica Bologna

Photo Credit: Flickr/MrsSparkyC

Share
, , , ,