Water is perhaps the most important nutrient in our diets.
Furthermore, many freshwater sources are not suitable for humans to drink. Hence, standards were provided by the Clean Water Act and the Safe Drinking Water Act to ensure that the population of the United States would have access to safe, usable water for drinking and other daily uses. It may be surprising to find that freshwater does not consist of pure water, but contains many dissolved ions. This tutorial explains the chemistry involved in the processes used by our public-water facilities to treat our water and make it safe for us to drink and for other human uses. At Washington University in St. Louis, this tutorial accompanies a first-semester experiment in which the students begin to explore the area of chemical reactions.