"The 53,000 water utilities in the United States deliver some of the safest drinking water in the world — a public health victory of unrivaled success that began in 1908 with chlorination campaigns in Jersey City and Chicago. Still, millions of individual cases of waterborne diseases occur annually and related hospitalization costs approach $1 billion each year. In 2007 and 2008, the most recent years for which figures are available, the Centers for Disease Control and Prevention recorded 164 waterborne disease outbreaks, almost entirely from protozoan cysts of the parasite Cryptosporidium."
"A Quest for Even Safer Drinking Water"
Source: NY Times, 08/27/2013