Drinking Water Regulation

Who Regulates Drinking Water Quality in the U.S.?

Public drinking water quality is regulated by the U.S. Environmental Protection Agency (EPA) by provisions of the Safe Drinking Water Act (SDWA), although individual states can apply and enforce their own standards if more stringent than those set by the EPA. The SDWA was originally passed by the U.S. Congress in 1974, and has been amended twice (1986, 1996) and now provides standards for drinking-water sources, treatment, and quality at the tap, as well as the disposal of wastewater underground. Private wells pumping groundwater that serve fewer than 25 people are not regulated. They should be tested regularly, however.

It is estimated that there are over 160,000 public drinking-water systems that fall under the aegis of the EPA standards. These standards are health-based and attempt to establish maximum levels (MCL—Maximum Contaminant Level) for possible contaminants that are below those that are thought to cause health problems (you can see specific contaminants and MCLs at EPA: Drinking Water Contaminants - Standards and Regulations). Of course, there are many contaminants for which there are insufficient data to establish stringent limits.

Over the past decade, bottled water, usually sealed in "plastic" containers has become quite popular worldwide. Accoring to bottledwater.org, in the U.S., over 15.9 billion gallons of bottled water were sold in 2022, revenues were more than $46 billion, assuming an average price of $1 per liter. Although convenience is certainly a factor, the perception has been that such water must be safe to drink—perhaps more safe than tap water—also drives bottled water sales. In the U.S., bottled water is actually regulated by the U.S. Food and Drug Administration (FDA), not the EPA. The FDA regulates bottled water as a food (requiring compliance with the Federal Food, Drug and Cosmetic Act) and does not require certified lab testing or violation reporting, even though the FDA does inspect bottling plants and ensures that suitable source waters are used. The FDA also has generally adopted limits for contaminants established by the EPA. Nonetheless, the FDA does not require bottled water companies to disclose to consumers the source of the water, treatment processes, or contaminants it contains, whereas the EPA requires public water systems to report results of their testing annually.