One hundred and fourteen years ago this September 26, an American city became the first in the nation to provide chlorinated drinking water to consumers on a continuous basis. Conceived by Dr. John L. Leal, a physician and advisor to the Jersey City Water Supply Company, chlorination of city water was a bold science-based experiment in public health.
At the turn of the last century, public health was poor in large cities such as Jersey City. Waterborne illness, especially typhoid fever, was rampant. High rates of waterborne illnesses exacted a terrible toll in human life and suffering. In a dramatic court proceeding, the Jersey City water company was given 90 days to propose a method to purify its drinking water. The water had been shown to be microbiologically unhealthful. Dr. Leal worked rapidly with other experts to develop a system to add chlorine to the water supply as it exited the city’s reservoir and flowed to consumer taps. The first chlorinated water arrived in homes, schools, and businesses on September 26, 1908.
As the typhoid fever rate in Jersey City plummeted, public health became the clear winner. Given the glowing example provided by Dr. Leal and his colleagues, drinking water chlorination spread like wildfire across the US and to many areas globally. The results of the new technology were astounding: a 2005 study concluded clean water was responsible for large declines in deaths in major US cities during the late 19th and early 20th centuries. The authors report, “A striking finding is that clean water technologies appear to have reduced typhoid fever by 26% initially and by another 65% after five years, leading to its near-eradication by 1936.” Continuous drinking water chlorination of US municipal water has been a resounding public health success!