Drinking water quality in the U.S. is regulated by state and federal laws and codes, which set maximum contaminant levels (MCLs) and Treatment Technique requirements for some pollutants and naturally occurring constituents, determine various operational requirements, require public notification for violation of standards, provide guidance to state primacy agencies, and require utilities to publish Consumer Confidence Reports.

The National Primary Drinking Water Regulations are water quality standards and water treatment rules set by EPA. Utilities must follow these regulations. The water quality standards and treatment techniques limit the levels of more than 90 contaminants (such as harmful germs and chemicals) that can get into tap water.

The Safe Drinking Water Act (SDWA) is federal law that protects Americans' drinking water quality. Under SDWA, EPA sets standards for drinking water quality for both natural and man-made contaminants. EPA oversees states, localities and water suppliers implementing those standards and protecting water sources.