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Fact Sheet: Announcement of Regulatory Determinations for

Priority Contaminants on the Drinking Water Contaminant

Candidate List

1. What is Today’s Action?

The Environmental Protection Agency (EPA) is announcing its final determination to not

develop National Primary Drinking Water Regulations (NPDWR) for nine contaminants from

the Contaminant Candidate List (CCL). EPA published its preliminary CCL regulatory

determination in the Federal Register on June 3, 2002 (67 FR 38222). 

2. What is the Contaminant Candidate List?

The Safe Drinking Water Act (SDWA), as amended in 1996, directs EPA to publish a list

(referred to as the Contaminant Candidate List, or CCL) of unregulated contaminants that

present a potential public health concern in drinking water. The CCL published in the Federal

Register on March 2, 1998 (63 FR 10273) contains 60 contaminants (50 chemicals and 10

microbes). The CCL was developed with considerable input from the scientific community and

stakeholders. The EPA uses the CCL to prioritize the Agency’s research and data collection

efforts for potential drinking water contaminants. An updated CCL is expected to be published

during 2003. 

3. What are CCL Regulatory Determinations?

SDWA also directs EPA to select at least five contaminants from the CCL every five

years (beginning in August 2001) to determine if regulating the contaminants as NPDWRs

would present a meaningful opportunity to reduce health risk. EPA must have adequate data to

evaluate when and where the contaminants occur, and the exposure and risk to public health. 

For many of the contaminants, additional data is needed before a decision can be made. The

Agency sets occurrence and research priorities for contaminants with insufficient data to support

a regulatory determination. 
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4. What contaminants from the CCL did EPA consider for regulation determinations?

The Agency has determined that the following nine contaminants have sufficient data and

information on which to base a regulatory determination. 

• Acanthamoeba – microscopic amoeba commonly found in the environment

• Aldrin – banned insecticide, used primarily on corn and cotton

• Dieldrin – banned insecticide, used primarily on corn and cotton

• Hexachlorobutadiene – used primarily to make rubber compounds

• Manganese – essential nutrient, occurs naturally, and has a variety of uses

• Metribuzin – herbicide used primarily on soybeans, potatoes, and alfalfa

• Naphthalene – intermediary manufacturing product and moth repellent

• Sodium – essential nutrient, naturally occurring element

• Sulfate – present in the diet, naturally occurring element

Reports on the CCL website (http://www.epa.gov/safewater/ccl/cclregdetermine.html)

present scientific data and summaries of technical information prepared for, and used in, the

regulatory determination. Information regarding each contaminant’s physical and chemical

properties, environmental fate, occurrence and exposure, health effects, analytical methods, and

treatment technologies are discussed. 

5. What comments did EPA receive?

EPA received and reviewed 15 public comments on the June 3, 2002, Federal Register

notice, “Announcement of Preliminary Regulatory Determinations for Priority Contaminants on

the Drinking Water Contaminant Candidate List”, (67 FR 38222). After careful consideration of

these public comments, EPA decided that regulatory action is not appropriate or necessary for

any of these nine CCL contaminants. The public comments, and EPA’s response to each, can be

obtained through EPA’s Water Docket at http://www.epa.gov/edocket/.

6. Additional Considerations

EPA is only making decisions on CCL contaminants that have sufficient information to

support a regulatory determination at this time. EPA continues to conduct research and/or to

collect occurrence information for the remaining 51 contaminants on the CCL.

EPA recognizes that stakeholders may have a particular interest in the timing of future

regulatory determinations for other contaminants on the CCL (e.g., perchlorate and methyl-tbutyl ether (MTBE)). Stakeholders may be concerned that regulatory determinations for such

contaminants should not necessarily wait until the end of the next regulatory determination

cycle. In this regard, it is important to recognize that the EPA is not precluded from: (1) taking

action on CCL contaminants if information becomes available and may proceed with regulatory
United States Environmental Protection Agency July 2003

Office of Water (4607M) EPA 815-F-03-007

www.epa.gov/safewater 3

determinations prior to the end of the next regulatory determination cycle (i.e., August 2006); or

(2) monitoring, conducting research, developing guidance, or regulating contaminants not

included on the CCL to address an urgent threat to public health (see SDWA section

1412(b)(1)(D)). 

7. Where can I find more information about drinking water standard development

and the CCL?

For additional information on the standard development process (including the CCL) and

more than 80 contaminants currently regulated by EPA, 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 Federal holidays,

from 9:00 a.m. to 5:30 p.m. Eastern Time.