Dyeing the Chicago River Green: How They Do It and Why
Every St. Patrick's Day, Chicago turns its river bright green. How a pollution test in 1961 became a city tradition, who does it, what's in the dye, and the debate over it.
There's nothing quite like it anywhere else: on the Saturday before St. Patrick's Day, boats race across the Chicago River downtown, crew members shake orange powder into the water, and within minutes the whole river turns a glowing, almost unreal green. Thousands of people line the bridges to watch.
It started with plumbers and pollution
The tradition goes back to 1961, when plumbers were using a fluorescent dye to trace sources of illegal pollution flowing into the river. The dye turned the water bright green, and someone had an idea: why not do this on St. Patrick's Day? The city's St. Patrick's Day dyeing began the following year, in 1962.
Who does it
The local plumbers union still runs it, the same families and crews year after year. The dyeing happens on the Saturday on or before March 17, the same day as the downtown parade.
What's in the dye
The original fluorescent dye turned out to be harmful, so organizers switched long ago to a vegetable-based powder. They use around 40 pounds of it, and the exact formula is a closely kept secret. It looks orange when it goes in and turns green when it hits the water. Organizers say it has been tested and is safe for the river.
The debate
Not everyone loves it. Groups like Friends of the Chicago River have argued that dyeing the river sends the wrong message about a river the city has worked hard to clean up. Supporters see it as a harmless, beloved tradition that brings people downtown in March.
Watching it
- Best views: the bridges and Riverwalk between about State Street and Columbus Drive.
- Get there early. The dyeing happens in the morning, before the parade.
- Dress warm. It's March in Chicago.
The green fades over the following day or so. The tradition doesn't. More Chicagoland traditions: Christkindlmarket.
Source (1)
Photo: 20170312 01 Chicago River (32421962937).jpg) by David Wilson from Oak Park, Illinois, USA, CC BY 2.0.