Safe Drinking Water Act (SDWA) Compliance Monitoring

Providing safe drinking water is a partnership that involves EPA, the states, tribes, public water systems and their operators, and certified laboratories that conduct required analyses of drinking water samples collected by public water systems.  EPA, states, and the tribes monitor compliance under the following Safe Drinking Water Act regulatory programs:

Public Drinking Water Systems

Public drinking water systems must meet health-based federal standards for contaminants, including performing regular monitoring and reporting.

The Public Water System Supervision (PWSS) program is designed to protect public health by ensuring the safety of drinking water.  The public drinking water systems regulated by EPA, and authorized states, territories and tribes provide drinking water to 90 percent of Americans. These public drinking water systems, which may be publicly- or privately-owned, serve at least 15 service connections or 25 persons. Private, individual household wells are not regulated by EPA. 

EPA’s and states’ primary means of monitoring public water system compliance with the SDWA and its implementing regulations is the review and evaluation of analytical results of water samples collected by public water systems.  These reports provide the water systems and regulators with the data they need to ensure that drinking water monitoring is ongoing and that the drinking water standards are being met.  When results indicate that a contaminant is present at a level that exceeds standards, states and EPA work with public water systems to take steps to prevent or remove the contaminants, and notify consumers so that they can make informed choices.

Underground Injection Control

Underground injection is the technology of placing fluids underground into porous formations of rocks through wells or similar conveyance systems.  The Underground Injection Control (UIC) program regulates the construction, operation, permitting and closure of injection wells.  It is designed to ensure that underground injection wells do not endanger any current and future underground sources of drinking water (USDWs).  EPA's and states' primary means of monitoring UIC compliance with SDWA and its implementing regulations is by inspecting for compliance with permit conditions on-site at UIC facilities.  

See underground injection control program information for the types and purposes of injection wells and for guidance on injection well construction and operation to prevent contamination of underground drinking water resources.