The Chicago River will turn emerald green again this March 15, continuing a six-decade tradition that defines the city’s St. Patrick’s Day celebrations. First started in 1962 by the Chicago Plumbers Union, Local 130, this vivid transformation draws thousands to the riverbanks each year. The Green Machine: How It Happens The dyeing begins precisely at 10 a.m. on Saturday, March 15, with boats dispersing a vegetable-based, food-grade formula that reacts with the water. The process takes about 45 minutes, with the vibrant green lasting anywhere from several hours to a couple of days, depending on water conditions and weather. “The … Continue reading Chicago St. Patrick’s Day: 60 Years of Green River Dyeing & Parade Crowds Exceeding 70K Set Record