Safe Drinking Water Act (1974)


The Safe Drinking Water Act (SDWA) of 1974 is the main federal law that ensures the quality of drinking water in the Unites States.


When implemented, the SDWA extended coverage of federal drinking water standards to all public water supplies. Previous standards, established by the U. S. Public Health Service beginning in 1914 and administered by the U.S. Environmental Protection Agency (EPA) since its creation in 1970, had legally applied only to water supplies serving interstate carriers (e.g., planes, ships, and rail cars engaged in interstate commerce). However, many states and municipalities complied with them on a voluntary basis.


Under the SDWA, public water supplies were defined as publicly or privately owned community water systems having at least 15 connections or serving at least 25 year-round customers or noncommunity water supplies serving at least 25 nonresidents for at least 60 days per year.


The SDWA required the EPA to promulgate primary drinking water regulations to protect public health and secondary drinking water regulations to protect the aesthetic and economic qualities of the water. The EPA was granted authority to regulate: 1) contaminants which may affect health (e.g., trace levels of carcinogenic chemicals that may or may not have an impact on human health); 2) compounds that react during water treatment to form contaminants; 3) classes of compounds (if more convenient than regulating individual compounds); and 4) treatment techniques, when it is not feasible to regulate individual contaminants (e.g., disinfection is required in lieu of standards on individual disease-causing microorganisms).

Recognizing the right and the responsibility of the states to oversee the safety of their own drinking water supplies, the SDWA authorized the EPA to grant primacy to states willing to accept primary responsibility for administering their own drinking water program. To obtain primacy, a state must develop a drinking water program meeting minimum federal requirements and must establish and enforce primary regulations at least as stringent as those promulgated by the EPA. States with primacy are encouraged to enforce the federal secondary drinking water regulations, but are not required to do so.

Other provisions of the SDWA authorized control of underground injection (e.g., waste disposal wells); required special protection of sole-source aquifers (those providing the only source of drinking water in a given area); authorized funds for research on drinking water treatment; required the EPA to conduct a rural water supply survey to investigate the quality of drinking water in rural areas; allocated funds to subsidize up to 75% of the cost of enlarging state drinking water programs; required utilities to publicly notify their customers when the primary regulations are violated; permitted citizens to file suit against the EPA or a state having primacy; and granted the EPA emergency powers to protect public health.


The 1986 SDWA amendments also prohibited the use of lead solder, flux, and pipe; authorized the EPA to treat Indian tribes as states, making them eligible for primacy and grant assistance; required the EPA to conduct a survey of drinking water quality on Indian lands; authorized the EPA to initiate enforcement action if a state fails to take appropriate action within 30 days; and increased both civil and criminal penalties for failure to comply with the SDWA.

Since 1986 was a congressional election year and every member of Congress wanted to go on record as having voted for safe drinking water, the amendments passed unanimously. However, Congress failed to provide federal funds to assist state programs in complying with the many new provisions of the SDWA. The average annual cost per state to comply with the SDWA by 1995 was estimated to be nearly $500 million.

Further amendments to SDWA were passed in 1996. The new amendments established a Drinking Water State Revolving Fund to finance state compliance costs for water treatment facilities, easier access to water quality information for consumers, and contamination prevention initiatives. The mandate for contaminant testing was changed to a risk-based prioritized system that granted the EPA the authority to decide whether or not to regulate a contaminant after completing a required review of five contaminants every five years. The amendments also called for specific risk assessments and final regulation of radon, arsenic, DBP/cryptosporidium, and sulfate.

The SDWA ranked the following drinking water standards as rule-making priorities:

Research and general acceptance

In the summer of 2010, the EPA launched its new Drinking Water Strategy initiative. Touted by the EPA as a “national conversation” on how to best improve the nation's public drinking water supply, the Strategy encompassed four basic principles: determining which water contaminants might best be addressed within groups, instead of individually; developing new technologies to deal with broad categories of drinking water contaminants and doing so in the most economical ways feasible; applying multiple federal statues governing water supplies in the effort to improve drinking water safety; and finally, encouraging cooperation between the states and the appropriate federal agencies to share a larger variety of data compiled from monitoring public water systems.

See also Lead ; Water quality .



Ertuo, Kudret, and Ilker Mirze, eds. Water Quality: Physical, Chemical, and Biological Characteristics. New York: Nova Science, 2010.

Langwith, Jacqueline, ed. Water. Detroit: Greenhaven Press, 2010.

Midkiff, Ken. Not a Drop to Drink: America's Water Crisis (and What You Can Do). Novato, CA: New World Library, 2007.

Symons, James M., et al., eds. Plain Talk About Drinking Water: Answers to Your Questions About the Water You Drink. Denver, CO: American Water Works Association, 2010.


Centers for Disease Control and Prevention. “Drinking Water.” (accessed August 16, 2012).

U.S. Environmental Protection Agency. “Water: Drinking Water.” (accessed August 13, 2012).

World Health Organization. “Drinking Water.” (accessed August 12, 2012).

World Health Organization. “Guidelines for Drinkingwater Quality.” (accessed August 12, 2012).


Water Environment Federation, 601 Wythe St., Alexandria, VA, 22314-1994, Fax: (703) 684-2492, (800) 666-0206, .

Stephen J. Randtke
Revised by Stacey Chamberlin

  This information is not a tool for self-diagnosis or a substitute for professional care.