Monday, March 13, 2006
Chicago River dyed green for St. Paddy's Day
Every year on St. Patrick's Day, the river is dyed green. The Pipefitters Union uses fluorescein dye which can also be used to study moving water. While in 1962, 100 pounds (45 kg) of dye were used, more recently the amount has been decreased to about 40 pounds (18 kg). The tradition of dying the river green for St. Patrick's Day dates back more than 40 years.