Chlorination of Drinking Water 1910 – An Effective Disinfectant

In 1997, LIFE magazine ran the headline: “The filtration of drinking water and the use of chlorine are probably the most important public-health development of the millennium”. 

Adding chlorine, a chemical element, to water is generally an effective treatment against bacteria, viruses and amoebae. It played an important role in the dramatic increase in life expectancy in developed countries in the 1900s. For example, waterborne bacterial diseases such as typhoid and cholera became rare in the United States after drinking water was chlorinated. After chlorination, chlorine remains in the water supply and continues to combat contamination from possible pipe leaks.

Although chlorine was known to be an effective disinfectant in the 1800s, water chlorination systems did not come into continuous use for public water supplies until the 1900s.

• In 1903, the community of Middelkerke in Belgium used chlorine gas to disinfect drinking water. 
• In 1908, a water company in New Jersey used sodium hypochlorite to chlorinate water. 
• In 1910, Major General Carl Rogers Darnall, a United States Army chemist and surgeon, used compressed, liquefied chlorine gas to purify water for soldiers at war. 
• The Army scientist Major William Lyster invented the Lyster cloth bag, which contained sodium hypochlorite and was used by soldiers in the field to purify, store and distribute water. 

According to spokespeople for Darnall Army Medical Center, “Few events in medicine have saved as many lives and prevented as much disease as Darnall's contribution to safe water.”

Chlorine applied during water disinfection can react with organic compounds in the water to produce trihalomethanes and haloacetic acids, which have the potential to cause cancer. However, this risk is low compared with the risk of waterborne diseases. Alternatives to chlorination include disinfection with ozone, chloramine and ultraviolet light.

About the Article Image: A well at the Great Mosque of Kairouan in Tunisia (a postcard dated 1900, overlaid on patterns from the prayer-hall door). Today, wells are sometimes periodically cleaned with a chlorine solution to reduce bacterial levels.

Historical Figures Mentioned in the Article: Carl Rogers Darnall (1867–1941), William J. L. Lyster (1869– 1947)

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