Imagine living in a world without chlorine disinfection of drinking water…You would have no idea when a dreaded disease might strike you down or strike down your children or other family members. This is the world that everyone in the U.S. lived in at the turn of the twentieth century.
–Michael J. McGuire in the foreword of ACC’s just-released Drinking Water Chlorination: A Review of U.S. Disinfection Practices and Issues. McGuire is also the author of The Chlorine Revolution: Water Disinfection and the Fight to Save Lives.
This revolution in public health McGuire mentions began in Jersey City in 1908 and soon cascaded to other U.S. cities. Before drinking water chlorination became commonplace, waterborne diseases like cholera, typhoid fever and dysentery killed thousands annually. As more and more communities began chlorinating their drinking water, corresponding death rates plunged dramatically. In fact, the treatment and distribution of drinking water has been called one of the greatest achievements of the twentieth century. Providing clean, safe drinking water requires source water protection, appropriately filtering and treating raw water and ensuring safe distribution of treated water to consumers’ taps. During the conventional treatment process, chlorine is added to drinking water as elemental chlorine (chlorine gas), sodium hypochlorite solution (bleach) or dry calcium hypochlorite. When applied to water, each forms free chlorine, which destroys or inactivates most disease-causing organisms such as bacteria and viruses. Chlorine-based alternative disinfectants include chloramine and chlorine dioxide.
Almost all U.S. drinking water treatment plants use some type of chlorine-based process—either alone or in combination with other disinfectants. Only chlorine-based disinfectants provide residual disinfection that helps prevent microbial growth or regrowth in the distribution system and in storage.
Intended for water quality professionals, students, researchers, and public health officials, the report is substantially updated and expanded from our previous (2003) edition and reviews:
- Chlorination and public health
- The risks of waterborne disease
- The challenge of disinfection byproducts (DBPs)
- Drinking water security
- Alternative disinfection methods
- The future of chlorine disinfection, including its role in achieving the UN’s Sustainable Development Goal 6 (“Ensure availability and sustainable management of water and sanitation for all”)
The review also includes a wide variety of informative and accessible figures, sidebars and tables. It can help provide water quality professionals the information they need to help evaluate and choose among available disinfection methods to match each system’s specific needs, resources and source water quality.
Unfortunately, we do not have to go back a century to see what contaminated water does to a community—an ongoing cholera epidemic in Haiti has already sickened more than 750,000 and killed almost 10,000 people. Chlorine can provide cost effective, scalable disinfection for remote rural villages and large cities alike, helping to bring safe water to those in need. Despite a century of continuous use and evolving challenges, drinking water chlorination will remain a cornerstone of waterborne disease prevention and public health protection in the U.S. and abroad.