Chlorine is a chemical element that was first used for the disinfection of drinking water in the 1890s. One such application of chlorine occurred in England following a 1897 typhoid epidemic where chlorine was used to disinfect the water mains. The first continuous use of chlorine in the United States was at a Jersey City, New Jersey water utility in 1908.
Chlorine is a well proven disinfectant for the prevention of water borne disease outbreaks.
Before chlorination of drinking water, typhoid fever killed about 25 out of 100,000 people in the U.S. annually, a rate that is close to the statistics of contemporarily automobile accidents. Unfortunately there are some pathogens that are resistant to chlorine. These organisms fall in the class of intestinal parasites with the most notorious being Giardia lamblia and Cryptosporidium. Generally these pathogens are found in surface waters , and the most effective means of protection is to keep the turbidity of the water at a very low level with multimedia filtration. A water plant operator checks the chlorination equipment at the Abingdon Water Plant.