East Chicago falls into the Grand Calumet River Watershed Area. This means that when it rains, all flowing surface water ends up draining into the Grand Calumet River, which then leads to Lake Michigan.
The US Great Lakes Water Quality Agreement currently has 25 listed "area of concerns" within the United States, with the Grand Calumet River being one of them. They define AOCs as "geographic areas designated by the Parties where significant impairment of beneficial uses has occurred as a result of human activities at the local level." An AOC is a location that has experienced environmental degradation.
While the Grand Calumet River is largely an area of concern due to legacy pollutants from industrial facilities prior to the Clean Water Act in 1972, it is important that we all do our part to help prevent additional pollution.