Environmental Protection
       Agertcy
                          Fact Sheet: Preliminary Regulatory
                          Determination for Perchlorate
The U.S. Environmental Protection Agency conducted extensive review of scientific data related
to the health effects of exposure to perchlorate from drinking water and other sources and found
that in over 99% of public drinking water systems, perchl orate was not at levels of public health
concern. Therefore, based on the Safe Water Drinking Act criteria, the Agency determined there
is not a "meaningful opportunity for health risk reduction" through a national drinking water
regulation.

The Agency is seeking comment on its preliminary determination not to regulate perchlorate in
drinking water at a national level. EPA will make a final determination for perchlorate after
considering information provided in the 30-day public comment period.

EPA is committed to working with states and localities to ensure public health is protected.
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 intends to issue a health advisory
at the time it issues its final regulatory determination for perchlorate, to assist states with their
local response.

EPA has drinking water regulations for more than 90 contaminants. To assess risks posed by
unregulated contaminants, EPA, in accordance with the Safe Drinking Water Act (SDWA),
identifies and  seeks public comment on a list of contaminants that may require regulation in the
future. At least every five years, EPA determines whether it should regulate some of the
contaminants from the list.

Questions and Answers

What is EPA's preliminary regulatory determination for perchlorate?

Less than 1%  of drinking water systems have perchlorate levels above the health reference level.
Therefore, the agency has determined that it does not occur frequently at levels of health
concern. EPA has also determined that there is not a meaningful opportunity for a national
drinking water regulation to reduce health risks.

To assist state and other public health officials, the agency intends to issue a health advisory for
perchlorate at the time of the final determination to provide information to federal, regional,
state, and local public health officials regarding potential health risks from perchlorate-
contaminated  drinking water.
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Office of Water (4607M)  EPA 815-F-08-009 October  2008  www.epa.qov/safewater

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What happens next?

EPA will accept public comment on its preliminary determination for 30 days following
publication of the preliminary determination in the Federal Register. EPA is also carrying out a
peer review of a modeling analysis supporting this determination. EPA will respond to the public
comments it receives on the preliminary determination and will review the comments from the
peer review of its model application. After considering comments, EPA plans to issue a final
regulatory determination for perchlorate by December 2008.

What is a regulatory determination?

A regulatory determination is a formal decision on whether EPA should initiate a rulemaking
process to develop a national primary drinking water regulation for a specific contaminant.

EPA identifies contaminants for decisions on whether drinking water regulations are needed and
for research prioritization with the drinking water Contaminant Candidate List (CCL). The
contaminants on the list are  known or anticipated to occur in public water systems. However,
they are currently not regulated with a national primary drinking  water regulation. Under the
Safe Drinking Water Act, EPA publishes a CCL every five years. EPA then makes regulatory
determinations from the list of contaminants. The first CCL was published in March 1998, and
the second CCL (CCL 2) was published in February 2005.

What is a health advisory?

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.

What criteria does EPA consider in making regulatory determinations?

When making a determination to regulate, the law requires consideration of three criteria:
   •   the potential  adverse effects of the contaminant on the health of humans,
   •   the frequency and level  of contaminant occurrence in public drinking water, and
   •   whether regulation of the contaminant presents a meaningful opportunity for reducing
       public health risks.

Do regulatory determinations impose any requirements on public water systems?

No. The notice seeks public comment on EPA's preliminary determination that a national
primary drinking water regulation is not necessary for perchlorate, and thus imposes no
requirements on public water systems. After review and consideration of public comment, EPA
Office of Water (4607M)  EPA 815-F-08-009 October 2008 www.epa.qov/safewater

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will issue a final regulatory determination. If a decision is made to regulate a contaminant, the
rulemaking process begins.

Where can I find more information about this notice and the perchlorate regulatory
determination ?

For information on the regulatory determinations for contaminants from the second CCL
including perchlorate, please visit http://www.epa.gov/safewater/ccl/reg_determine2.html. For
general information on drinking water, please visit the EPA Safewater Web site at
http://www.epa.gov/safewater or contact the Safe Drinking Water Hotline at 1-800-426-4791.
The Safe Drinking Water Hotline is open Monday through Friday, excluding legal holidays,
from 10:00 a.m. to 4:00 p.m., Eastern time.
Office of Water (4607M)   EPA 815-F-08-009 October  2008  www.epa.qov/safewater

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