The Safe Drinking Water Act

The 1996 Amendments to SDWA requires that every 5 years US EPA establish a list of contaminants which are known or anticipated to occur in public water systems and may require future regluations under SDWA. The list is developed with significant input from the scientific community and other interested parties. After establishing this contaminant candidate list, US EPA identifies contaminants which are priorities for additional research and data gathering. US EPA uses this information to determine whether or not a regulation is appropriate and this process is repeated for each list, every 5 years.

In order to support this decision-making, US EPA has also established a National Contaminant Occurrence Database (NCOD), which stores data on the occurrence of both regulated and unregulated contaminants. US EPA is also required to list and develop regulations for monitoring certain unregulated contaminants. This monitoring data will provide the basis for identifying contaminants that may be placed on future Contaminant Candidate Lists and support the US EPA Administrator's decisions to regulate contaminants in the future.

Health effects

Adverse health effects from contaminants that may occur in drinking water include acute effects that may immediately impact health and chronic effects that may occur if contaminants are ingested at unsafe levels over many years. Drinking water that meets US EPA's health-based standards is generally safe. People who are not healthy as a result of illness, age, or weakened immune systems, are more likely to be at risk from certain contaminants that may be found in drinking water. Infants and very young children are also more susceptible to some contaminants. Individuals concerned about their particular situations should consult their health care providers. For a list of current drinking water standards, information on potential health effects of specific contaminants, and guidance to persons with severely compromised immune systems, see the US EPA web site at http://www.epa.gov/safewater/dwhealth.html or call the Safe Drinking Water Hotline at 1-800-426-4791.