Chicago Water Quality: Yesterday
During the Industrial Revolution, the city of Chicago rapidly became a bustling metropolis with varied industries and a growing population. However, its growth was jeopardized by the practice of disposing industrial, animal, and human waste into the Chicago River and Lake Michigan. By the 1850s, after several cholera epidemics, city planners recognized the critical public health need to create a reliable source of clean drinking water.
In 1861, the Chicago Board of Public Works began construction of an extensive water system that is still in use today. A 2-mile tunnel was excavated under Lake Michigan, creating a clean water intake protected by a “crib” – a structure that surrounds and protects the intake shaft from possible pollutants. Engineers and miners toiled 24 hours a day, 6 days a week to finish the construction of Two-Mile Crib within a year. As the city grew, six additional cribs were added over the next 50 years, including the Carter H. Harrison, Edward F. Dunne, Wilson Avenue, and William E. Dever Cribs.
At the same time, a complex sewer system was developed to carry wastewater away from the drinking water intakes in Lake Michigan. Originally, waste discharged into the Chicago River often found its way into Lake Michigan, carried by heavy rain or melting snow. By constructing a series of four channels, including the 28-mile Sanitary and Ship Canal, the flow of the Chicago River was reversed to carry sewage well away from drinking water supplies of Lake Michigan.