Since the 1850s, chlorine has been used as a disinfectant to kill harmful bacteria in water itself or the pipes that transport it. It has helped end a number of major threats to public health. Although chlorine in water is essential at the treatment plant and in the water distribution system, it is no longer necessary once the water reaches your home.
Though chlorine is vital for stopping the spread of disease, its benefits come at a price. Chlorine tastes and smells bad. It dries skin and hair, fades clothes (bleach is made of chlorine) and can dry out the rubber seals in appliances, shortening their lives.