Why might chlorine be added to drinking water?
To kill pathogens..........
Addition of chlorine to water apparently kills the microbes that might be otherwise responsible for typhoid, cholera, and dysentery - which historically have been scourges of humanity. Sometimes, the local water authority adds too much chlorine to the water, and you can actually smell the chlorine in the water.
And yet the fact that we (or at least most of us) can open a tap in our homes, and get potable, drinkable water that poses no health hazard is something that we should probably appreciate more than we do. This is especially true in that not only do we drink the water, we also bathe in it, and flush the lav with it, and even clean the motor with it........ I am glad I was not born 200 years ago.....
In the same vein, the addition of fluoride salts to water supplies has long been performed to improve dental health; look up