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St. Patrick's Day tradition: Why Chicago dyes its river green

About 40 pounds of green dye are dumped into the river each year to celebrate St. Patrick’s Day.
Posted at 4:50 PM, Mar 12, 2023
and last updated 2023-03-12 16:50:57-04

For more than 60 years, Chicago’s uniqueSt. Patrick’s Daytradition has had people seeing green.

And it’s not just the sea of bagpipers, people in costumes, or politicians decked in their sashes to celebrate Irish heritage; it also includes thousands who gather to watch the mile-long Chicago River turn bright, bright green.

"Spring is coming. So, it’s good to see this green," said Gloria Cervantes of Cicero, Illinois.

About 40 pounds of green dyeare dumped into the river. Some boats spray it, while others mix it to get the color just right.

The well-loved tradition was started by plumbers in the 1960s by the Chicago Journeymen Plumbers Local Union.

The dye was initially used to detect leaky pipes and pollution, but when the Head of the Union, Stephen Bailey, noticed the color on the plumber’s white overalls as the perfect shade of shamrock, the idea to greenify the river was born.

"This experience is just amazing. No words to say how I'm feeling now. It's beautiful," said Gabriella Dos Sangos, who is from Brazil and seeing the river for the first time.

People celebrating St. Patrick's Day Parade in New York City.

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Thousands of people from around the world and the country flock to the Windy City for this very event.

"We continue to come back every year. So, this is generation number three," said Cole Brandon, from Kalamazoo, Michigan.

While the ingredients of the emerald dye remain a secret, the Union says it is vegetable-based and safe. But an environmental group, the Friends of the Chicago River, pushed back on that response because of the lack of transparency.

"There is no way to know what the dye is or whether it is harmless," the group said in a statement. They stressed that the river is a living ecosystem, not a sewer system as it had been in the past.

"I hope someone took the time to investigate if it's doing any harm to our rivers and lakes. If they find out that it is, it needs to stop," said Chicago resident Brett Horton.

For now, there’s no stopping this tradition.

While Chicago was the first to dye its waters green, other cities have followed suit, like Savannah, Georgia’s fountain, and San Antonio’s River Walk. Still, Chicago prides itself on being the original and most famous.

"Chicago is one of the top cities in my list, you know, and this is amazing," said Amanda Passos, who is visiting from Brazil.

The Union says the green dye will flow to the Mississippi River and will eventually make its way to the Gulf and then to the Atlantic, creating a green path from Chicago to Ireland.