History of Drinking Water Treatment

A Century of U.S. Water Chlorination and Treatment: One of the Ten Greatest Public Health Achievements of the 20th Century

American drinking water supplies are among the safest in the world. The disinfection of water has played a critical role in improving drinking water quality in the United States. In 1908, Jersey City, New Jersey was the first city in the United States to begin routine disinfection of community drinking water. Over the next decade, thousands of cities and towns across the United States followed suit in routinely disinfecting their drinking water, contributing to a dramatic decrease in disease across the country (Fig 1).

Graph showing the death rate for infectious diseases, per 100,000 population - United States, 1900-1996. In 1900, the death rate was 800 per 1000 people and 40 states have health departments. Around 1915, the first continuous use of chlorine in water in the United States Occurred, and in 1917 the Spanish Influenza pandemic struck the world. In the early 1920s, the last human-to-human transmission of plague occurred. After 1940, penicillin was first administered. In the 1950s, the Salk vaccine was first given. In the 1960s, Congress passed the Vaccination Assistance Act.

Figure 1. Crude death rate* for infectious diseases - United States, 1900-1996

*Per 100,000 population per year.

Learn more about the history of U.S. drinking water chlorination

The occurrence of diseases such as cholera and typhoid dropped dramatically. In 1900, the occurrence of typhoid fever in the United States was approximately 100 cases per 100,000 people. By 1920, it had decreased to 33.8 cases per 100,000 people. In 2006, it had decreased to 0.1 cases per 100,000 people (only 353 cases) with approximately 75% occurring among international travelers. Typhoid fever decreased rapidly in cities from Baltimore to Chicago as water disinfection and treatment was instituted. This decrease in illness is credited to the implementation of drinking water disinfection and treatment, improving the quality of source water, and improvements in sanitation and hygiene.

It is because of these successes that we can celebrate over a century of public drinking water disinfection and treatment – one of the greatest public health achievements of the 20th century.

CDC. A Century of U.S. Water Chlorination and Treatment: One of the Ten Greatest Public Health Achievements of the 20th Century. Morb Mortal Wkly Rep. 1999;48(29):621-9.