District News Articles

  2. The next time you enjoy a refreshing glass of water from the tap, you might want to offer a toast to what has been helping to keep water safe and healthy for American families since 1908.  One hundred years ago, Jersey City, N.J., and Chicago’s union stockyards added chlorine to water supplies, launching America’s reliance on chlorine to disinfect drinking water.

    The Boonton Reservoir incorporated the first chlorination system for drinking water in the United States.  Photo courtesy United Water.
    Chlorine destroys germs and has helped to virtually eliminate waterborne illnesses such as cholera and typhoid that once killed thousands of Americans each year.  Indeed, as the 20th century neared its conclusion, Life magazine declared: “The filtration of drinking water plus the use of chlorine is probably the most significant public health advancement of the millennium.”
    Efforts to improve drinking water date to the time when ancient civilizations established themselves around water sources.  As early as 4,000 B.C., Sanskrit and Greek writings recommended filtering water through charcoal, exposing it to sunlight, boiling and straining to reduce visible cloudiness.  Other ancient civilizations as diverse as Chinese, Arabian, Egyptian and Indian tried other coagulants, including alum, almonds, powdered ginger, cornmeal, crushed oyster shells and even toasted biscuits.
    These early attempts were based on the notion that clear water not only tasted and smelled better, but was not apt to make a person sick.  What went unrecognized until the 19th century was that the cause of most waterborne illnesses was not visible and could not necessarily be filtered out.
    Killing Germs that Cause Disease
    Standing on the sturdy shoulders of their predecessors, Louis Pasteur and other scientists in the 1800s verified “germ theory,” which explained how organisms too small to see with the naked eye could transmit disease through water and other media.  During the very late 19th and early 20th centuries, scientists turned their attention to removing “germs” in public water supplies that caused epidemics of typhoid and dysentery, as well as cholera.  They tried slow sand filtration first.
    “While filtration was a fairly effective treatment method for reducing turbidity, it was disinfectants like chlorine that played the largest role in reducing the number of waterborne disease outbreaks in the early 1900s,” according to the U.S. Environmental Protection Agency.
    In 1905, chlorine was added to London’s water supply and a typhoid epidemic ceased.  Three years later, chlorination of Jersey City’s Boonton Reservoir and Chicago’s Bubbly Creek started a revolution that made chlorine the most widely used disinfectant in the United States.  In that same momentous year, British scientist Harriet Chick figured out a relationship between germ kill efficiency and contact time with a disinfectant.
    Based on Chick’s Law, cities across the United States adopted water chlorination rapidly, with more than 1,000 water systems using this life-saving technology by 1918.  Then in the 1920s, Maryland Department of Health engineer Abel Wolman perfected the formula for the appropriate application of chlorine to water supplies.
    Chlorine Saves U.S. Lives, Helps Extend Lifespan
    In the years before chlorine’s introduction, waterborne diseases claimed thousands of American lives every year.  For example, there were more than 27,000 typhoid deaths during the Civil War.  The widespread use of chlorine and improved sanitary engineering practices reduced the number of reported waterborne disease outbreaks and individual cases of waterborne illness dramatically.
    In the decade 1900-1910, average U.S. life expectancy was 49 years.  By 2005, a child born in the United States could expect to live 77.9 years, the U.S. Centers for Disease Control and Prevention (CDC) reported in September 2007.  According to the CDC, the steep decline in infectious diseases made possible by vaccinations, chlorination of drinking water and other advances in public sanitation and hygiene directly contributed to this nearly 60 percent increase in life expectancy.
    Chlorine: The Backbone of U.S. Drinking Water Infrastructure
    Over the past 100 years, a national infrastructure has been developed using chlorine as a drinking water disinfectant.  Chlorinated systems deliver water through nearly 900,000 miles of pipe to more than 200 million Americans.  The U.S. enjoys one of the safest drinking water supplies in the world, in large part due to disinfection and treatment provided by water systems across the country.  Chlorine disinfectants destroy germs and have helped to virtually eliminate waterborne illnesses--such as cholera and typhoid fever--that once killed thousands of Americans each year.
    Today, nearly nine out of 10 U.S. public water systems rely on chlorine in one form or another.  Many systems use chlorine gas (elemental chlorine).  Others use liquid chlorine bleach (sodium hypochlorite) or calcium hypochlorite (often also used in swimming pools).  Each form produces “free chlorine” to destroy disease-causing microorganisms.  Chlorine offers numerous other benefits, as well.  For example, chlorine removes many unpleasant tastes and odors and certain metal contaminants, such as iron and manganese.  Chlorine also provides a residual level of disinfectant to help keep water safe from the treatment plant to consumers’ taps.
    All of the vast water-treatment infrastructure and the public health benefits it delivers track back to 1908, when Jersey City and the Union Stockyards of Chicago made very wise decisions to add chlorine to their water supplies.  To celebrate the 100th anniversary of the use of chlorine as a drinking water disinfectant, the American Chemical Council has developed an extensive Web site, Chlorine Chemistry: 100 Years of Safer Lives, with a timeline, a quiz, a graph illustrating the dramatic decline in waterborne disease in the United States, and a series of articles related to disinfection.