The U. S. Environmental Protection Agency (EPA) established the Public Water System Supervision (PWSS) Program under the authority of the 1974 Safe Drinking Water Act (SDWA). Under the SDWA and the 1986 Amendments, EPA sets national limits on contaminant levels in drinking water to ensure that the water is safe for human consumption. These limits are known as maximum contaminant levels (MCLs). For some regulations, EPA established treatment techniques in lieu of an MCL to control unacceptable levels of contaminants in drinking water. The Agency also regulates how often public water systems monitor their water for contaminants and report the monitoring result to the states or EPA. Generally, the larger the population served by a water system, the more frequent the monitoring and reporting requirements. In addition, EPA requires PWSS to monitor for unregulated contaminants to provide data for future regulatory development. Finally, EPA requires public water systems to notify the public when they have violated these regulations.

The SDWA allows states and territories to seek EPA approval to administer their own PWSS programs. The authority to run a PWSS Program is called primacy. To receive primacy, States must meet requirements laid out in the SDWA and regulations, including the adoption of drinking water regulations that are at least as stringent as the Federal regulations and a demonstration that they can enforce the program requirements. Georgia sought and received primacy for the PWSS program in 1977.

http://www.gaepd.org/Documents/fullrpt9.html

http://water.epa.gov/lawsregs/guidance/sdwa/laws_statutes.cfm