Dr. John Snow and the Drinking Water Discovery

One hundred and fifty years ago this month, an English doctor named John Snow traced the source of a deadly outbreak of cholera to a water pump on the city of London's Broad Street. This pump served much of the surrounding neighborhood and it was in this area that many people had sickened and died.

At that time, the microscope hadn't been invented, no one understood what "germs" were, and no one knew that drinking water could be contaminated and make people sick. Instead, Dr. Snow relied on interviews with the neighbors, and on counting cases and marking them on maps. When he discovered that those people who drank from the Broad Street pump were more likely to become ill or die than those who did not, legend has it that he removed the handle from the pump and stopped the outbreak. For his work and because of the methods he used, Dr. Snow is considered widely to be the father of modern public health.

Today, we are still using an updated version of Dr. Snow's methods to track and control diseases...and we are still dealing with diseases caused by dirty drinking water. Yet unlike people living in 1854 when Dr. Snow made his famous discovery, we can prevent sickness caused by drinking contaminated water, as well as stop outbreaks. Read on for more about what we are doing to make drinking water safe for everyone.

The Water People Drink and the CDC Safe Water System

Did you know that people are processing safe, clean water with inexpensive, easy-to-get materials, in areas of the world where clean water is hard to find? The Safe Water System (SWS) is one way this is done. A collaborative project of CDC and public and private organizations, the SWS helps people learn how to make their own drinking water with inexpensive tools and materials they already have around them.

• For people who live in developed countries, safe drinking water is as close as the nearest tap. However, many people in developing countries are not so fortunate. How do they get their drinking water? More >>
• Visit the CDC Safe Water System website to learn how and why this program was developed, how it works, and how to start one. More >>

Do You Know Where Your Drinking Water Comes From? Safe Drinking Water in the United States

Are you one of the 52% of Americans who depend on ground water for your drinking water, either from a public source or private well? Does your water come from a public source such as ground water (a well) or surface water (a river)?

Make sure your water is safe to drink. Depending on where you get your water from, schedule a well checkup or order a Consumer Confidence Report from your local water utility. More >>

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Last edited September 7, 2004

Centers for Disease Control and Prevention
National Center for Infectious Diseases