Today is celebrated as ‘St. Patrick’s Day’ and one of the great traditions to mark the event is the green dying of the Chicago River. This is performed by the Plumbers Union, who use an environmental friendly dye, used in their everyday work, to create the effect that draws thousands of spectators. In Chicago, the St.Patrick’s Day parade, sponsored by the Plumbers Union, is held on the Saturday before St. Patrick’s Day, so that all working families have the opportunity to participate and enjoy the festivities.