Rapid urban growth of Chicago after incorporation as a city in 1837, gave rise to cholera
epidemics aggravated by poor drainage and uncertain drinking water quality. Muddy streets and cesspools were the way of life until an innovative sewer system was installed beginning in 1856. Lacking effective technology to treat large quantities of sewage, the river became grossly polluted, threatening the water supply, Lake Michigan. Several schemes to deal with the pollution through trial and error failed, until a massive flood caused the creation of the Sanitary District of Chicago. A long canal, surmounting the subcontinental divide, allowed the polluted river to flow away by gravity to the Illinois and Mississippi Rivers by 1900. Using Lake Michigan water for dilution was practiced until replaced by construction of sewage collection and treatment infrastructure. The Clean Water Act’s requirement to end combined sewer
overflow was met with construction of a huge tunnel and reservoir system to capture and treat all overflow. Initial opposition to the diversion of Lake Michigan water was resolved through litigation, protecting the lake, providing water for navigation on the Illinois Waterway, and providing safe drinking water for Northeast Illinois.
Download the presentation by Dick Lanyon: Metro Chicago Water Systems: Ensuring Healthy and Sustainable Resources (July, 2023).