Public Health Basics: Why You Shouldn’t Drink the River Water – Lessons from John Snow to Modern-Day Water Safety

“Don't drink the river water!” might be something you’ve heard someone tell a young child on a hot day while swimming at the bottom of a small waterfall, but have you stopped to wonder why drinking the river water isn’t a good idea? Or, why most tap and bottled water sources are preferred over sipping directly from a standing lake, river or stream? Neighborhood pumps were common before the modern invention of indoor plumbing. The idea that water could be contaminated and unsafe to drink was an unheard of idea in 1854 when Englishman John Snow proposed it. After several residents using the same London pump came down with Cholera, Snow began to investigate. Working across sectors, with people from a variety of professions, Snow believed that “unhealthy air”- miasma theory- was not the cause of the Cholera outbreak. After the pump’s handle was eventually removed, the number of Cholera deaths and cases subsided. Snow’s methods, including mapping Cholera cases and interviews with residents to find out if they had used the pump’s water, or touched the pump’s handle, are some Epidemiological principles still used today! Access to clean, fresh water is still a concern for many areas of the world, including some cities in the United States. However, much of the global north, or more developed countries, including the US and Canada, require regular water testing in piped water that is going to be used for drinking or cooking.

Here, public water undergoes testing on a regular schedule. In addition to ensuring that public tap water is free of contaminants, such as bacteria or lead, the water testing also ensures that the water has the appropriate amount of chemicals such as chlorine (to keep the water clean) and fluoride. Groundwater, lake, stream, or river water are not usually required to meet the same standards as drinking water. In recent years, testing wastewater has allowed public health officials to learn if an outbreak of a disease is occurring within a small group of residents. Similar to the pump in London, wastewater from a group of buildings will be sent to the same underground pipes. If wastewater from one location is positive for Disease A, then officials know that someone in the neighborhood has Disease A. However, they do not know WHO has Disease A, and thus will usually contact everyone who is emptying wastewater into the pipe to let them know that someone in the geographical area has Disease A. To learn more about wastewater testing, visit the CDC. 

Note- If you have well water, recommendations for testing may differ from public (e.g., city or town) water. To learn more about getting your well water tested from the NYS Department of Health and the CDC.