Background on Private Drinking Water and Public Health

What Is Private Drinking Water?

Private drinking water includes

  • Private (or household) wells,
  • Springs,
  • Cisterns,
  • Water storage tanks, and
  • Trucked water.

About 1 in 9 American residents get their drinking water from private wells. These systems may have contaminants that can affect health.

Photo of a private well in an Ohio backyard

Private well in an Ohio backyard

Can Private Drinking Water Cause Health Problems?

Yes. Private drinking water is not always treated to remove contaminants. In addition, because private drinking water systems are not covered by the Safe Drinking Water Act, they may not be tested regularly for contaminants. Without regular testing, people may be exposed to things that can affect their health without knowing it or being able to do anything about it.

What Contaminants Might Be in Private Drinking Water Sources?

Contaminants such as germs, chemicals, or radionuclides can contaminate wells and other private drinking water sources. These contaminants could also affect health.

Corrosive groundwater can cause lead to leach from pipes, plumbing fixtures, and solder that contain lead into the public drinking water supply. Lead also poses a threat to private well users. Learn more about corrosive groundwater and what to do when private well owners find lead in their drinking water.

Note: Fluorides are naturally occurring compounds. Low levels of fluorides can help prevent dental cavities. High levels can cause fluorosis.


How Do Contaminants Get Into Private Drinking Water?

Private drinking water can become contaminated in a variety of ways. Some regions are prone to high levels of certain contaminants in rock or soil that dissolve into water sources. For example, the northeastern part of the United States has high levels of naturally occurring arsenic in rock formations that can leach into the water during the process of drilling and constructing the well. Other times, pathogens from farm animals can infiltrate poorly designed or lined wells and enter groundwater used for drinking. In addition, flooding and other emergencies can introduce contaminants to wells, springs, and other individual water sources.

Photo of a boy drinking water from a glass.

What Is Our Unique Role in this Work?

We fund state and local health departments that serve communities and populations using small drinking water systems (for example, private wells, springs, cisterns). These sources are not covered by the federal Safe Drinking Water Act, which focuses on public water systems. Through our Safe WATCH program, we fund health departments to

  • Identify and close program performance gaps,
  • Increase use of efficient practices among drinking water programs,
  • Increase the services reach of drinking water programs, and
  • Reduce exposures to waterborne contaminants.