By Maemie Chan, Melissa Corey, Lauren May, Leilani Dec, Caroline Nelson, and Chase Anderson
The Chicago River is 156 miles long, counting tributaries, and is two to 21 feet in depth. It used to be Chicago's water supply.
Lake Michigan is the third largest lake in the US and Chicago is lucky to have it so near. Lake Michigan is 306 miles long and 118 miles wide, with an area of 22,300 square miles. The maximum depth is about 922 feet. The surface is 577 feet above sea level. the level of Lake Michigan has been rising over the past two decades.
Rainfall in a typical year for Lake Michigan is distributed like this:
Chicago seemed like a perfect place to build a city with all its fresh water lake nearby. The Chicago River seemed like it would give good water forever. Yet it did not take long for people to discover that this fortune would not last long. People took their water from the Chicago River without caring about purification. But as the population increased, so did pollution. In 1854 cholera struck Chicago as sewage was emptied directly into the river and carried out into Lake Michigan.
Years later pollution was still a problem. To get clean water for an enlarging population a 2-mile tunnel was build right under Lake Michigan out to offshore water-intake cribs to carry water beneath the polluted shoreline and straight to a water distribution system. But the river still posed a pollution problem, as a natural tributary to Lake Michigan.
In 1900 the river's flow was reversed to carry polluted water away from the city's fresh water supply. But the heart of the problem still remained. As population grew, so did pollution, both man-made and natural. Filtration and purification treat our water, but the question remains: what besides our water flows from the tap, and is it safe to drink?
Congress passed the Safe Drinking Water Act in 1974 and amended it in 1986. The Environmental Protection Agency has various rules to ensure our water is safe. Public water systems are required to collect samples from the water system for testing at laboratories.
Lead poses one health threat. It is considered to be hightly toxic to infants and pregnant women. Water for drinking or cooking should never be drawn from the hot water tap, since hot water dissolves lead more quickly. Chicago has one of the highest lead rates in our country. More than 52 percent of homes have too much lead in the water that flows through their taps.
Water that evaporates fro the lake comes back in the form of rain. Unfortunately when the rain comes back it is sometimes acid rain. All rain is somewhat acid. Acid rain is rain that is made unuasually acidic by pollutants in the air. Factories and power plants give off chemicals when burning oil and coal. Auto exhaust contains sulfer dioxide, which also adds to the acid in the rain. The result is that lakes, rivers, and streams get polluted and fish and plants are harmed.
Thermal pollution is another problem. Significant increases of temperature caused by the industrial discharge of heated water may be harmful to aquatic life.
Other major things that pollute the water are oil, litter, and gasses.
Go back to the Water in Chicago's Community page.