Key points
- CDC estimates at least 1.1 million people in the United States get sick every year from germs in drinking water.
- Legionella germs are the most common cause of illness outbreaks linked to drinking water.
- If you are concerned about your tap water, contact your water utility or health department.
Overview
In the United States, 9 out of 10 people get their tap water from a regulated public water system. Most other people living in the United States get their tap water from a privately owned well.
In the early 1900s, communities across the United States started routinely treating tap water to remove harmful germs and chemicals. Water treatment has greatly reduced the number of people who get sick from drinking water. However, sometimes tap water still gets contaminated with harmful germs or chemicals and makes people sick.
Avoid getting sick from your water
U.S. data
CDC estimates at least 1.1 million people in the United States get sick every year from germs in drinking water. This is about 1 in every 300 people.
See below for the germs that most often cause illness outbreaks in drinking water.
Public tap water
Top 5 causes of outbreaks linked to public (community) drinking water in the United States during 2010–2022:
Private tap water
Top 5 causes of outbreaks linked to private drinking water in the United States during 2010–2022:
Private drinking water includes privately owned wells and rainwater collection systems.
Find more data about outbreaks linked to water using the "NORS View" tab on CDC's BEAM dashboard.
- Gerdes ME, Miko S, Kunz JM, et al. Estimating Waterborne Infectious Disease Burden by Exposure Route, United States, 2014. Emerging Infectious Diseases. 2023;29(7):1357-1366. doi:10.3201/eid2907.230231.