The U.S. Environmental Protection Agency (EPA) is seeking advice from the National Academy of Sciences (NAS) before making a final determination on whether to issue a national regulation for perchlorate in drinking water.
The agency also is issuing an interim health advisory of 15 parts per billion (ppb) to assist state and local officials in addressing local contamination of perchlorate in drinking water and making a corresponding change to the factors it considers in cleaning up Superfund sites. States have the right to establish and enforce drinking water standards, and EPA encourages state-specific situations to be addressed at the local level. EPA expects to issue a final health advisory concurrent with the final regulatory determination for perchlorate.
"This is a sensible step for protecting public health and preserving regulatory options as the science of perchlorate is reviewed," said Benjamin H. Grumbles, EPA’s assistant administrator for water.
On Oct. 10, 2008, the agency issued a preliminary regulatory determination for public comment in the Federal Register. The notice described the agency’s decision that there is not a "meaningful opportunity for health risk reduction" through a national drinking water regulation for perchlorate. The agency received more than 32,000 comments on the notice.
After considering public comments, as well as recommendations from EPA advisory groups and offices, EPA is asking the NAS to provide additional insight on various issues. Specifically, EPA is asking the NAS to evaluate its derivation of the Health Reference Level of 15 ppb, the use of modeling to evaluate impacts on infants and young children, and the implication of recent biomonitoring studies. The agency is also asking the NAS how it should consider the role of perchlorate relative to other iodide uptake inhibiting compounds and if there are other public health strategies to address this aspect of thyroid health.
EPA is replacing the existing preliminary remediation goal of 24.5 ppb with the interim health advisory value of 15 ppb. This goal will be used as a consideration when establishing cleanup levels for perchlorate at Superfund sites.
A regulatory determination is a formal decision by EPA as to whether it should initiate development of a national primary drinking water regulation for a specific contaminant under the Safe Drinking Water Act. EPA has drinking water regulations for more than 90 contaminants. Every five years, EPA develops a Contaminant Candidate List to consider for regulation and then makes regulatory determinations on some of the contaminants based on scientific information on health effects, occurrence in drinking water and the opportunity for risk reduction.
A health advisory provides technical guidance to federal, state and other public health officials on health effects, analytical methods and treatment technologies associated with drinking water contamination. Health advisories also contain guidance values that are concentrations of a contaminant in drinking water that are likely to be without adverse health effects.
More information on the perchlorate health advisory is available at: www.epa.gov/safewater/contaminants/unregulated/perchlorate.html