A century ago, in 1908, chlorine chemistry’s germ-defeating properties were demonstrated in drinking water in two very different settings in the United States. First, chlorination transformed animal feed water, drawn from a highly polluted stream in Chicago’s Union Stockyards, into a product that exceeded the purity of city water. Days later, in Jersey City, chlorinated water was supplied for the first time on a permanent basis to a large U.S. municipality. The results included a dramatic decline in the local typhoid fever rate and a water supply that, according to a 1928 sanitary engineering report, “is not only of a high sanitary quality, but…it compares favorably with the best in the country.”
