Enteroviruses and Drinking Water from Private Wells

What are enteroviruses?

Enteroviruses are a group of small viruses. There are two subgroups of enteroviruses: viruses that cause polio and viruses that cause non-polio-related diseases. The non-polio enteroviruses are second only to cold viruses as the most common cause of viral infections in humans. Enterovirus infections are most likely to occur during the summer and fall. They cause an estimated 10-15 million or more illnesses a year in the United States. Most enteroviruses are found in every part of the United States and throughout the world.

For more information about enteroviruses illness and treatment, please visit CDC’s enteroviruses page.

Where and how do enteroviruses get into drinking water?

Enteroviruses may be found in water sources such as private wells. Wells become contaminated when feces from infected humans enter the water through different ways, including sewage overflows, sewage systems that are not working properly, and polluted storm water runoff. Wells may be more vulnerable to such contamination after flooding, particularly if the wells are shallow, have been dug or bored, or have been submerged by floodwater for long periods of time.

How can I find out whether there is an enterovirus in my drinking water?

If you suspect a problem and your drinking water comes from a private well, you may contact your state certification officerexternal icon for a list of laboratories in your area that will perform tests on drinking water for a fee.

How do I remove enteroviruses from my drinking water?

To kill or inactivate enteroviruses, bring your water to a rolling boil for one minute (at elevations above 6,500 feet, boil for three minutes). Water should then be allowed to cool, stored in a clean sanitized container with a tight cover, and refrigerated. Because of the small size of the viruses, a point-of-use filter will not remove them from water.

You may also disinfect your well, although enteroviruses may be fairly resistant to disinfection. Contact your local health department for recommended procedures. Remember to have your well water tested regularly, at least once a year, after disinfection to make sure the problem does not recur.