Public water system, 1974-2017

State environmental policy
U.S. environmental policy
Endangered species policy
State endangered species
Federal land policy
Environmental terms

A public water system provides water for human consumption through pipes and other infrastructure. For purposes of the federal Safe Drinking Water Act, a public water system is defined as a system that regularly serves water for human consumption to at least 25 individuals. Despite its name, a public water system may be publicly or privately owned. Public water systems can include municipal systems, gas stations, campgrounds, schools, and more. As of March 2017, there were approximately 152,700 public water systems, both privately and publicly owned.

Background

The federal Safe Drinking Water Act was enacted in 1974 and amended in 1986, 1996, and 2016. The act established programs for drinking water standards and water treatment requirements for public water systems and authorized federal funding for drinking water infrastructure projects.

Enforcement is divided between the federal government and the states. States have authority to implement and enforce drinking water regulations if they adopt standards that mirror national requirements, adopt adequate enforcement mechanisms, conduct water system monitoring, and maintain records and compliance information. As of March 2017, 49 states had primary authority over public water systems (all but Wyoming. The original 1974 act gave the EPA discretionary authority to regulate drinking water contaminants and gave states primary authority for implementing and enforcing the act's requirements on public water systems.

Types of water systems

Public water systems in the United States are distinguished in the following ways:

• Community water systems deliver water to the same residences year-round. As of March 2017, community water systems served approximately 299 million U.S. residents—92 percent of the U.S. population. Community systems can serve populations ranging from 500 people or fewer to 100,000 people or more. Around 8 percent of community water systems served populations of 10,000 or more, which accounted for approximately 76 percent of the U.S. population—246 million people. Among all community water systems, 71 percent relied on groundwater and 29 percent on surface water as of March 2017.
• Non-transient, non-community water systems deliver water to at least 25 of the same people for at least six months per year, but not year-round. These systems are used within schools, factories, office buildings, and hospitals, which generally have their own on-site water systems. As of March 2017, these water systems served approximately 6.2 million people.
• Transient, non-community water systems provide water in places where people do not remain for a long period of time, such as gas stations or campgrounds. These systems are open for at least 60 days per year. As of March 2017, these systems served approximately 12.7 million people.

See also

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  Safe Drinking Water Act

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  Water quality criteria

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  Wetland

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  Glossary of environmental terms