CDC - Drinking Water Home

Drinking Water

Drinking water comes from a variety of sources including public water systems, private wells, or bottled water. Ensuring safe and healthy drinking water may be as simple as turning on the tap from an EPA-regulated public water system. Other water sources may need a water filter, a check on water fluoridation, or an inspection to ensure a septic tank is not too close to a private well. It is important to know where drinking water comes from, how it’s been treated, and if it's safe to drink.

Drinking Water Topics

Public Water Systems

Quality & Testing, Regulations, Sources, Treatment...

Bottled Water

Basics, Immunocompromised Individuals, Fluoride...

Camping, Hiking, Travel

Safe Drinking & Recreational Water, Illness...

Private Water Systems

Wells (Basics, Testing, Treatment), Nonpublic Water Sources...

Water & Nutrition

Health Benefits, Daily Water Needs, Weight Management...

Water Fluoridation

Benefits, Safety, Guidelines, Fact Sheets...

Drinking Water Fast Facts

Regulations

All public water systems in the U.S. are required to follow the standards and regulations set by the U.S. Environmental Protection Agency (EPA).
EPA regulations that protect public water systems do not apply to privately owned wells or other individual water systems. Owners of private wells are responsible for ensuring that their well water is safe from contaminants.

Prevention

The impact of clean water technologies on public health in the U.S is estimated to have had a rate of return of 23 to 1 for investments in water filtration and chlorination during the first half of the 20th century ⁴.
Community water fluoridation prevents tooth decay safely and effectively. Water fluoridation has been named one of 10 great public health achievements of the 20th century ⁵.

Two types of Drinking Water Systems: Public and Individual

There are two types of drinking water systems in the United States. They are:

Public water systems that are subject to United States Environmental Protection Agency (EPA) regulations.
Individual water systems that are not subject to EPA regulations.

According to the EPA, approximately 286 million Americans receive their tap water from a community water system. These public water systems are monitored and regulated as set by the EPA.

An estimated 15% of Americans, or about 45 million people, get their water from private ground water wells that are not subject to EPA regulations. Private ground water wells can provide safe, clean water. However, well water can also become contaminated, leading to illness. It is the responsibility of well owners to maintain and treat their well ^1,2,3.

U.S. Environmental Protection Agency. Factoids: drinking water and ground water statistics for 2007.
U.S. Environmental Protection Agency. Private Drinking Water Wells.
U.S. Census Bureau. National and State Population Estimates.
Cutler, D., G. Miller, 2004. The role of public health improvements in health advances: the 20th century United States. [PDF - 50 pages] National Bureau of Economic Research. Working Paper 10511. Cambridge, MA, USA.
CDC. Achievements in public health, 1900-1999: Fluoridation of drinking water to prevent dental caries. MMWR Morb Mortal Wkly Rep. 1999;48:933-40.

* Based on tracking of waterborne outbreaks from 1971-2008. Only confirmed causes have been included in the analyses. For outbreaks with multiple causes, each agent counted toward the total. Outbreak reporting is dependent on capacity to detect, investigate, and report the outbreaks. This requires health effects to be measured and these health effects to be easily linked to water exposure. Clusters of illnesses associated with chronic chemical exposures are not part of waterborne disease outbreak reporting or part of these lists.