The Chicagoist will be launching later but in the meantime please enjoy our archives.

How The Chicago River Was Dyed Green

By Chuck Sudo in Arts & Entertainment on Mar 16, 2012 3:00PM

In Chicago we just marked the return of the South Side Irish Parade, so tomorrow's official parade by the city means residents here have a second chance to be Irish for a day.

One of the unique local touches to Chicago's St. Patrick's Day celebrations is the dyeing of the Chicago River a nearly radioactive looking Kelly green. It's a 51-year tradition that came about by happenstance.

A couple of plumbers discovered the orange dye they used to detect leaks and illegal discharges of sewage into the Chicago River turned the water that Irish green that's so ubiquitous this time of year. They brought the news to Chicago Journeymen Plumbers Local 110 business manager Stephen Bailey, who then asked around and ultimately received permission to try and dye the river green.

The Plumbers Local union is charged with dyeing the river green every year. They first used 100 pounds of the vegetable dye, which kept the river green for about a week. Today, 40 pounds of vegetable dye is mixed into the river using motorboats, which is enough to keep the river a Shamrock green for about four-to-five hours, after which the river reverts back to its murky, polluted green. If one thinks about it, it's a sad commentary on the state of the Chicago River's water quality that vegetable dye and pollution can create such a stunning image. One wonders how tougher EPA water quality standards for Chicago's waterways and a vote by the Metropolitan Water Reclamation District last year to stop dumping partially treated sewage into the waterway will effect the tradition in the future.