Water: The Six-Year Review
Six-Year Review of Drinking Water Standards
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The Safe Drinking Water Act (SDWA) requires EPA to review each National Primary Drinking Water Regulation (NPDWR) at least once every six years and revise them, if appropriate. The purpose of the review, called the Six-Year Review, is to identify those NPDWRs for which current health effects assessments, changes in technology, and/or other factors provide a health or technical basis to support a regulatory revision that will maintain or strengthen public health protection.
Statutory Requirements for the Six-Year Review
Section 1412(b)(9) of the Safe Drinking Water Act states,
"The Administrator shall, not less often than every 6 years, review and revise, as appropriate, each national primary drinking water regulation promulgated under this title. Any revision of a national primary drinking water regulation shall be promulgated in accordance with this section, except that each revision shall maintain, or provide for greater, protection of the health of persons."
Overview of the Six-Year Review Efforts
Since the 1996 SDWA Amendments were enacted, the Agency has completed two comprehensive reviews of existing National Primary Drinking Water Regulations. The links below provide more information about the first and second Six-Year Reviews.
Review of the Fluoride Drinking Water Regulation
On January 7, 2011, the Agency announced its intent to review the national primary and secondary drinking water regulations for fluoride. By initiating the current review, EPA is following up on a commitment made in the second Six Year Review (SY2), which was released in March 2010. In SY2, the Agency indicated that the Office of Water was in the process of updating its health and exposure assessments and that when the Agency finalized these assessments, it would review the existing drinking water regulation to determine whether revisions are appropriate.
The Agency released the new risk and exposure assessments on January 7, 2011. These assessments address recommendations made by the National Research Council (NRC) of the National Academies of Science (NAS).The NRC review was conducted at the request of the EPA in 2003 as part of the first Six Year Review, in which EPA found that new health and exposure data were available on orally ingested fluoride. In 2006, NRC published their evaluation in a report entitled Fluoride in Drinking Water: A Scientific Review of EPA's Standards. In this report, the NRC recommended that EPA update its fluoride risk assessment to include new data on health risks and better estimates of total exposure. Based on the new assessments, EPA will begin the process of reviewing the current drinking water standards for fluoride to decide whether revisions are appropriate.
- Fact sheet for more information about the results of the new risk assessments and EPA's next steps for evaluating the fluoride drinking water standard (PDF) (10 pp, 55 K, About PDF).
Other information or activities related to fluoride:
Other Related Efforts
In a related effort, SDWA includes a process that we must follow to identify and list unregulated contaminants which may require a national drinking water regulation in the future. EPA must publish this list of unregulated contaminants (called the Contaminant Candidate List or CCL) and decide whether to regulate at least five or more contaminants on the list (called Regulatory Determinations). EPA uses this list of unregulated contaminants to prioritize research and data collection efforts to help us determine whether we should regulate a specific contaminant.