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Billing Code 6560-50-P

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 141

[EPA-HQ-OW-2012-0217 FRL-_______-_______]

RIN 2040-A537

Drinking Water Contaminant Candidate List 4– Draft

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

SUMMARY: 

EPA is publishing for public review and comment a draft list of contaminants that are currently 

not subject to any proposed or promulgated national primary drinking water regulations

(NPDWRs), that are known or anticipated to occur in public water systems (PWSs), and which 

may require regulation under the Safe Drinking Water Act (SDWA). This draft list is the fourth

Contaminant Candidate List (CCL 4) published by the agency since the SDWA amendments of 

1996.

This Draft CCL 4 includes 100 chemicals or chemical groups and 12 microbial contaminants. 

The EPA seeks comment on the Draft CCL 4, and on improvements to the CCL selection 

process to be considered for future CCLs.

DATES: Comments must be received on or before [INSERT DATE 60 DAYS AFTER DATE 

OF PUBLICATION IN THE FEDERAL REGISTER]. 
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ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-2012-0217,

by one of the following methods:

• Email: www.regulations.gov: Follow the on-line instructions for submitting 

comments.

• Mail: Water Docket, Environmental Protection Agency, Mail code: 28221T, 1200 

Pennsylvania Ave., NW, Washington, DC 20460. 

• Hand Delivery: Water Docket, EPA Docket Center (EPA/DC) EPA West, Room 

3334, 1301 Constitution Ave., NW, Washington, DC 20004. Such deliveries are 

only accepted during the Docket’s normal hours of operation, and special 

arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. EPA-HQ-OW-2012-0217. EPA's 

policy is that all comments received will be included in the public docket without change and 

may be made available online at www.regulations.gov, including any personal information 

provided, unless the comment includes information claimed to be Confidential Business 

Information (CBI) or other information whose disclosure is restricted by statute. Do not submit 

information that you consider to be CBI or otherwise protected through www.regulations.gov or 

email. The www.regulations.gov website is an “anonymous access” system, which means EPA 

will not know your identity or contact information unless you provide it in the body of your 

comment. If you send an e-mail comment directly to EPA without going through 

www.regulations.gov, your e-mail address will be automatically captured and included as part of 

the comment that is placed in the public docket and made available on the Internet. If you submit 

an electronic comment, EPA recommends that you include your name and other contact 
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information in the body of your comment and with any disk or CD-ROM you submit. If EPA 

cannot read your comment due to technical difficulties and cannot contact you for clarification, 

EPA may not be able to consider your comment. Electronic files should avoid the use of special 

characters, any form of encryption, and be free of any defects or viruses. For additional 

instructions on submitting comments, go to Section I.B of the GENERAL INFORMATION 

section of this document. 

Docket: All documents in the docket are listed in the www.regulations.gov index. 

Although listed in the index, some information is not publicly available, e.g., CBI or other 

information whose disclosure is restricted by statute. Certain other material, such as copyrighted 

material, will be publicly available only in hard copy. Publicly available docket materials are 

available either electronically in www.regulations.gov or in hard copy at the Water Docket, 

EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW, Washington, DC 20004. The 

Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 

legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the 

telephone number for the EPA Docket Center is (202) 566-2426.

FOR FURTHER INFORMATION CONTACT: For information on chemical contaminants 

contact Meredith Russell, Office of Ground Water and Drinking Water, Standards and Risk 

Management Division, at (202) 564-0814 or e-mail russell.meredith@epa.gov. For information 

on microbial contaminants contact Hannah Holsinger, Office of Ground Water and Drinking

Water, Standards and Risk Management Division, at 202-564-0403 or email 

holsinger.hannah@epa.gov. For general information contact the EPA Safe Drinking Water 

Hotline at (800) 426-4791 or e-mail: hotline-sdwa@epa.gov.
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Abbreviations and Acronyms

ATSDR -- Agency for Toxic Substances and Disease Registry

AWWA -- American Water Works Association 

CA -- California

CASRN -- Chemical Abstract Services Registry Number

CDC -- Centers for Disease Control and Prevention

CCL -- Contaminant Candidate List

CCL 1 -- EPA’s First Contaminant Candidate List

CCL 2 -- EPA’s Second Contaminant Candidate List

CCL 3 -- EPA’s Third Contaminant Candidate List

CCL 4 -- EPA’s Fourth Contaminant Candidate List

CFR -- Code of Federal Regulations

CUS/IUR -- Chemical Update System/Inventory Update Rule

EPA -- United States Environmental Protection Agency

ESA -- ethanesulfonic acid

FL -- Florida

FR -- Federal Register

GAMA -- The California State Water Resources Control Board’s Groundwater Ambient 

Monitoring Assessment program

HPC -- Heterotrophic Plate Count

IL -- Illinois
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IOM -- Institute of Medicine

IRIS -- Integrated Risk Information System

MCL -- Maximum Contaminant Level 

MCLG – Maximum Contaminant Level Goal

MMWR -- Morbidity and Mortality Weekly Report

NC -- North Carolina

NCOD -- National Contaminant Occurrence Database

NDWAC -- National Drinking Water Advisory Council

NRC -- National Academy of Science’s National Research Council

NPDWR -- National Primary Drinking Water Regulation

NTP -- National Toxicology Program

OH -- Ohio

OPP -- Office of Pesticide Programs

OSRTI -- Office of Superfund Remediation and Technology Innovation

PCCL 3 -- Preliminary Contaminant Candidate List 3

PCCL 4 -- Preliminary Contaminant Candidate List 4

PDP -- Pesticide Data Program developed by USDA

PFOA -- perfluorooctanoic acid

PFOS -- perfluorooctane sulfonic acid

PPRTVs -- Provisional Peer Reviewed Toxicity Values

PWS -- public water system

SAB -- Science Advisory Board
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SDWA -- Safe Drinking Water Act

SD -- South Dakota

STORET -- EPA’s Storage and Retrieval database of water quality monitoring data collected by 

water resource management groups across the U.S.

TRI -- Toxics Release Inventory

TT -- Treatment Technique - an enforceable procedure or level of technological performance,

which public water systems must follow to ensure control of a contaminant

TX -- Texas

UCM -- Unregulated Contaminant Monitoring

UCMR 1 -- First Unregulated Contaminant Monitoring Rule

UCMR 2 -- Second Unregulated Contaminant Monitoring Rule

US -- United States of America

USDA -- United States Department of Agriculture

USEPA -- United States Environmental Protection Agency

USGS -- United States Geological Survey

WHO -- World Health Organization

WI -- Wisconsin

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information

A. Does this Action Impose Any Requirements on My Public Water System?

B. What Should I Consider as I Prepare My Comments for EPA?
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II. Purpose, Background, and Summary of This Action

A. What is the Purpose of This Action?

B. Statutory Requirements for CCL, Regulatory Determinations and Unregulated 

Contaminant Monitoring

1. Contaminant Candidate List

2. Regulatory Determinations

3. Unregulated Contaminant Monitoring

C. Interrelationship of the CCL, Regulatory Determinations, and Unregulated Contaminant 

Monitoring

D. Brief History of Previous CCLs and Regulatory Determinations

1. The First Contaminant Candidate List

2. The Regulatory Determinations for CCL 1 Contaminants

3. The Second Contaminant Candidate List 

4. The Regulatory Determinations for CCL 2 Contaminants

5. The Third Contaminant Candidate List

6. The Regulatory Determinations for CCL 3 Contaminants

E. Summary of the Approach Used to Identify and Evaluate Candidates for CCL 4

1. Carry Forward of CCL 3 Contaminants

2. Summary and Evaluation of CCL 4 Nominated Contaminants

3. Evaluation of Previous Negative Regulatory Determinations

F. What is on EPA’s Draft CCL 4?

III. Request for Comment
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IV. EPA’s Next Steps

V. References

I. General Information

A. Does this Action Impose Any Requirements on My Public Water System?

The Draft Contaminant Candidate List 4 (CCL 4) and the Final CCL 4, when published, 

will not impose any requirements on regulated entities. Instead, this action notifies interested 

parties of the availability of EPA’s Draft CCL 4 and seeks comment on the contaminants listed. 

B. What Should I Consider as I Prepare My Comments for EPA? 

You may find the following suggestions helpful for preparing your comments:

 Explain your views as clearly as possible.

 Describe any assumptions that you used.

 Provide any technical information and/or data you used that support your views.

 Provide full references for any peer reviewed publication you used that support your 

views.

 Provide specific examples to illustrate your concerns.

 Offer alternatives.

Make sure to submit your comments by the comment period deadline. To ensure proper 

receipt by EPA, identify the appropriate docket identification number in the subject line on the 

first page of your response. It would also be helpful if you provided the name, date, and Federal 

Register citation related to your comments.
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II. Purpose, Background, and Summary of This Action

This section briefly summarizes the purpose of this action, the statutory requirements, 

previous activities related to the Contaminant Candidate List (CCL), and the approach used to 

develop the Draft CCL 4. 

A. What is the Purpose of This Action?

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

list every five years of currently unregulated contaminants that may pose risks for drinking water 

(referred to as the Contaminant Candidate List, or CCL). This list is subsequently used to make 

regulatory determinations on whether to regulate at least five contaminants from the CCL with a 

national primary drinking water regulation (NPDWR) (SDWA Section 1412(b)(1)). The purpose 

of today’s action is to present EPA’s draft list of contaminants on the CCL 4, a description of the 

selection process and the rationale used to make the list. Today’s action only deals with the CCL

4. Regulatory determinations for contaminants on the CCL are made as part of a separate agency

action.

EPA requests comment on the Draft CCL 4 and suggestions for further improvements to 

the selection process to be considered for future CCLs.

B. Statutory Requirements for CCL, Regulatory Determinations and Unregulated Contaminant 

Monitoring 

1. Contaminant Candidate List
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Section 1412(b)(1) of the SDWA, as amended in 1996, requires EPA to publish the CCL

every five years. The SDWA specifies that the list must include contaminants that are not subject 

to any proposed or promulgated NPDWRs, are known or anticipated to occur in PWSs, and may

require regulation under the SDWA. The unregulated contaminants considered for listing shall 

include, but not be limited to, substances identified in section 101(14) of the Comprehensive 

Environmental Response, Compensation, and Liability Act of 1980, and substances registered as 

pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act. The SDWA also 

directs the agency to consider the health effects and occurrence information for unregulated 

contaminants to identify those contaminants that present the greatest public health concern 

related to exposure from drinking water. The statute also directs the agency to take into 

consideration the effect of contaminants upon subgroups that comprise a meaningful portion of 

the general population (such as infants, children, pregnant women, the elderly, and individuals 

with a history of serious illness, or other subpopulations) that are identifiable as being at greater 

risk than the general population of adverse health effects due to exposure to contaminants in 

drinking water. EPA considers age-related subgroups as “lifestages” in reference to a 

distinguishable time frame in an individual’s life characterized by unique and relatively stable 

behavioral and/or physiological characteristics that are associated with development and growth. 

Thus, childhood should be viewed as a sequence of lifestages, from conception through fetal 

development, infancy, and adolescence (see http://www2.epa.gov/children/early-life-stages). 

2. Regulatory Determinations

Section 1412(b)(1)(B)(ii) of the SDWA, as amended in 1996, requires EPA at five year 

intervals to make determinations of whether to regulate or not to regulate no fewer than five 
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contaminants from the CCL. The 1996 SDWA Amendments specify three criteria to determine 

whether a contaminant may require regulation:

 the contaminant may have an adverse effect on the health of persons; 

 the contaminant is known to occur or there is a substantial likelihood that the contaminant 

will occur in public water systems with a frequency and at levels of public health 

concern; and

 in the sole judgment of the Administrator, regulation of such contaminant presents a 

meaningful opportunity for health risk reduction for persons served by public water 

systems. 

If EPA determines that these three statutory criteria are met and makes a final determination 

to regulate a contaminant, the agency has 24 months to publish a proposed Maximum 

Contaminant Level Goal1(MCLG) and NPDWR2. After the proposal, the agency has 18 months 

to publish and promulgate a final MCLG and NPDWR (SDWA section 1412(b)(1)(E))3. 

3. Unregulated Contaminant Monitoring

Section 1445 of the SDWA mandates that EPA promulgate regulations (known as the 

Unregulated Contaminant Monitoring Rule or UCMR) to establish criteria for a monitoring 

program for unregulated contaminants. The SDWA requires all large public water systems and a 

 

1 The MCLG is the "maximum level of a contaminant in drinking water at which no known or anticipated adverse 

effect on the health of persons would occur, and which allows an adequate margin of safety. Maximum contaminant 

level goals are non-enforceable health goals." (40 C.F.R. 141.2; 42 U.S.C. 300g-1)

2 An NPDWR is a legally enforceable standard that applies to public water systems. An NPDWR sets a legal limit 

(called a maximum contaminant level or MCL) or specifies a certain treatment technique (TT) for public water 

systems for a specific contaminant or group of contaminants. The MCL is the highest level of a contaminant that is 

allowed in drinking water and is set as close to the MCLG as feasible using the best available treatment technology 

and taking cost into consideration.

3

 The statute authorizes a nine month extension of this promulgation date.
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representative sample of smaller public water systems to monitor for unregulated contaminants. 

The statute requires EPA to issue a list every five years of not more than 30 unregulated 

contaminants to be monitored. The SDWA also specifies that EPA include the results of such 

monitoring, along with monitoring data for regulated contaminants and reliable information from 

other public and private sources, in a national drinking water occurrence database. EPA 

developed the National Contaminant Occurrence Database (NCOD) to contain the monitoring 

data from the UCMR program and the other data as specified by the SDWA. The current UCMR

(UCMR 3) requires monitoring for 30 contaminants (28 chemicals and 2 viruses) (77 FR 26071, 

May 2, 2012 (USEPA, 2012a)). Sampling will occur during 2013-2015. Twenty-one 

contaminants on the CCL 3 and twenty contaminants on the Draft CCL 4 are included on the 

UCMR 3. This occurrence information will be used in the development of future CCLs and 

regulatory determinations. 

C. Interrelationship of the CCL, Regulatory Determinations, and Unregulated Contaminant 

Monitoring 

The CCL is the first step in evaluating the subset of potential contaminants that may

require future NPDWRs. The CCL serves as the initial screening of potential contaminants, and 

inclusion on the CCL does not mean that any particular contaminant will necessarily be regulated 

in the future. The UCMR provides a mechanism to obtain nationally representative occurrence 

data for contaminants. Most unregulated contaminants chosen by EPA for monitoring have been 

selected from the CCL. When selecting contaminants for monitoring under the UCMR, EPA 

considers the availability of health effects data and the need for national occurrence data for 
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contaminants, as well as analytical method availability and cost, availability of analytical 

standards, and laboratory capacity to support a nationwide monitoring program when selecting 

contaminants. The contaminant occurrence data collected under the UCMR serves to better 

inform future CCLs and regulatory determinations. Contaminants on the CCL are evaluated to 

see which ones have sufficient information to allow the agency to make a regulatory

determination. Those contaminants with sufficient information to make a regulatory

determination are then evaluated based on the three statutory criteria in the SDWA Section 

1412(b)(1) to determine whether a regulation is required (called a positive determination) or not 

required (called a negative determination). EPA must make regulatory determinations for at least 

five contaminants listed on the CCL every five years. For those contaminants without sufficient 

information to allow the agency to make a regulatory determination, EPA encourages research to 

provide the information needed to determine whether to regulate the contaminant. Today’s action 

deals only with the CCL 4 and not with the UCMR or regulatory determinations.

D. Brief History of Previous CCLs and Regulatory Determinations

1. The First Contaminant Candidate List

The first CCL (CCL 1) was published on March 2, 1998 (63 FR 10274 (USEPA, 1998)). 

CCL 1 was developed based on recommendations by the National Drinking Water Advisory

Council (NDWAC) and review by technical experts. It contained 50 chemicals and 10 microbial 

contaminants/groups. EPA consulted with the scientific community, including the Science 

Advisory Board, on a process for developing the first CCL. 
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2. The Regulatory Determinations for CCL 1 Contaminants

EPA published its final regulatory determinations for a subset of contaminants listed on 

CCL 1 on July 18, 2003 (68 FR 42897 (USEPA, 2003)). EPA identified nine contaminants from 

the 60 contaminants listed on CCL 1 that had sufficient data and information available to make 

regulatory determinations. The nine contaminants were Acanthamoeba, aldrin, dieldrin, 

hexachlorobutadiene, manganese, metribuzin, naphthalene, sodium, and sulfate. The agency

determined that an NPDWR was not necessary for any of these nine contaminants at that time. 

The agency issued guidance on Acanthamoeba and health advisories for manganese, sodium, and 

sulfate. 

3. The Second Contaminant Candidate List

The agency published its Final CCL 2 on February 24, 2005 (70 FR 9071 (USEPA, 

2005)). The CCL 2 carried forward the 51 remaining chemical and microbial contaminants from

CCL 1 that did not have regulatory determinations. 

4. The Regulatory Determinations for CCL 2 Contaminants

EPA published its final regulatory determinations for a subset of contaminants listed on 

CCL 2 on July 30, 2008 (73 FR 44251 (USEPA, 2008b)). EPA identified 11 contaminants from 

the 51 contaminants listed on CCL 2 that had sufficient data and information available to make 

regulatory determinations. The 11 contaminants were boron, the dacthal mono- and di-acid 

degradates; 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (DDE); 1,3-dichloropropene; 2,4-

dinitrotoluene; 2,6-dinitrotoluene; s-ethyl propylthiocarbamate (EPTC); fonofos; terbacil; and 

1,1,2,2-tetrachloroethane. The agency made a final determination that an NPDWR was not 
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necessary for any of these 11 contaminants. New or updated health advisories were issued for 

boron, the dacthal degradates, 2,4- dinitrotoluene, 2,6- dinitrotoluene and 1,1,2,2-

tetrachloroethane. 

5. The Third Contaminant Candidate List

The agency published its Final CCL 3 on October 8, 2009 (74 FR 51850 (USEPA, 

2009e)). The CCL 3 contained 104 chemicals or chemical groups and 12 microbial

contaminants. In developing CCL 3, EPA improved and built upon the process that was used for 

CCL 1 and CCL 2. In 1998, the agency requested advice from the National Academy of 

Sciences’ National Research Council (NRC) on how to improve the CCL process. The NRC

proposed a broader, more reproducible process to identify the CCL than the process used by EPA 

in the first and second CCLs. The NRC recommended that EPA develop and use a multi-step 

process for creating CCL 3 and future CCLs, whereby a broadly defined “universe” of potential 

drinking water contaminants is identified, assessed, and reduced to a preliminary CCL (PCCL) 

using simple screening criteria (NRC, 2001). All of the contaminants on the PCCL would then 

be assessed in more detail using classification tools to evaluate the likelihood that specific 

contaminants could occur in drinking water at levels that pose a public health concern. In 2002, 

the agency sought input from the National Drinking Water Advisory Council (NDWAC) on how 

to implement the NRC’s recommendations to improve the CCL process. NDWAC agreed that 

EPA should proceed with the NRC’s recommendations and provided some additional 

considerations and recommendations in a 2004 report (NDWAC, 2004). 
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Based on these consultations and input, as well as substantial input from experts and the 

public, EPA developed a multi-step process to select contaminants for the CCL 3, which 

included the following key steps: 

 Identification of a broad universe of potential drinking water contaminants (the CCL 3 

Universe);

 Screening the CCL 3 Universe to a preliminary CCL (PCCL) using screening criteria 

based on the potential to occur in public water systems and the potential for public health 

concern; 

 Evaluation of the PCCL contaminants based on a more detailed evaluation of occurrence 

and health effects using a scoring and classification system; and

 Incorporating public input and expert review in the CCL 3 process. 

EPA convened several expert review panels for peer review of both the process and the 

contaminants. As the result of peer review, refinements to the process were made. EPA sought 

and incorporated public input by seeking nominations for contaminants to be considered for the 

Draft CCL 3 and published the Draft CCL 3 with an opportunity for public comments before the 

list was finalized. EPA also allowed opportunity for and considered contaminants identified by

surveillance efforts, which included ongoing collaboration with internal EPA offices and other 

Federal agencies and the review of scientific publications and data, to enable consideration of 

new information on contaminants. Any contaminants identified through the nomination and/or 

surveillance mechanisms were considered at any step of the CCL 3 process, but only the 

contaminants that met the criteria applied for all steps of the CCL 3 process were included on the 

Draft CCL 3.
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Exhibit 1 illustrates the CCL 3 multi-step approach previously described. This 

generalized process is applied to both chemical and microbial contaminants, though the specific 

execution of particular steps differs between them.

Exhibit 1. Schematic of CCL process

A complete description of the CCL 3 process can be found in the Draft and Final CCL 3 

Federal Register notices (73 FR 9628, February 21, 2008 (USEPA, 2008a) and 74 FR 51850, 

October 8, 2009 (USEPA, 2009e)). Supporting documents that explain each stage of the CCL 3 

process in further detail (i.e., identifying the Universe, screening to the PCCL, and the 

classification of the PCCL to the CCL) can be found at: 

http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3_processflowdiagram.cfm and in the 

CCL 3 docket at www.regulations.gov (Docket ID: EPA-HQ-OW-2007-1189).

Evaluation 

Expert Review 

Universe

PCCL

Draft CCL

Surveillance

And

 Nomination 

STEP 1

Identifying the

Universe

STEP 2

Screening 

to a PCCL

STEP 3

Classification

of the PCCL to 

the CCL

Final CCL

Public Comment
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6. The Regulatory Determinations for CCL 3 Contaminants

On February 11, 2011, as a separate action, the agency issued a positive regulatory

determination for perchlorate, a chemical listed in CCL 1, CCL 2, and CCL 3 (76 FR 7762) 

USEPA, 2011)). Recently, EPA has published preliminary regulatory determinations for five 

unregulated contaminants (xx FR xxxxx (USEPA, 2014a)). The five contaminants include: 1,3-

dinitrobenzene; dimethoate; strontium; terbufos; and terbufos sulfone. The agency is making

preliminary determinations to regulate one contaminant (strontium) and to not regulate four 

contaminants (1,3-dinitrobenzene, dimethoate, terbufos, and terbufos sulfone). Therefore, the 

agency is removing perchlorate and these five contaminants from the Draft CCL 4, pending the 

result of the final regulatory determinations for CCL 3. 

E. Summary of Approach Used to Identify and Evaluate Candidates for CCL 4

EPA is proposing an abbreviated evaluation and selection process for CCL 4. This

abbreviated CCL 4 process includes a three pronged approach: (1) carrying forward CCL 3 

contaminants (minus those with regulatory determinations), (2) seeking and evaluating 

nominations from the public for additional contaminants to consider, and (3) evaluating any new 

data for those contaminants with previous negative regulatory determinations from CCL 1 or 

CCL 2 for potential inclusion on the CCL 4. While EPA is proposing this abbreviated process for 

developing the CCL 4, the agency also seeks comments for how to further improve upon the 

process developed for CCL 3 as a tool for future CCLs. 
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1. Carry Forward of CCL 3 Contaminants

All contaminants listed on CCL 3 were carried forward to the Draft CCL 4 with the 

exception of perchlorate, for which a positive regulatory determination was made, and the 5 CCL 

3 contaminants with preliminary regulatory determinations (listed in Section D.7. of this notice), 

pending their final determinations. This carry forward process is consistent with that previously

used in CCL 2. The EPA believes that it is appropriate for the Draft CCL 4 to carry forward the 

CCL 3 contaminants for the following reasons: (1) In developing the CCL 3, the agency 

implemented a robust process recommended by the NRC and the NDWAC to screen and score 

the universe of potential contaminants, (2) EPA used the best available, peer-reviewed data and 

information to evaluate contaminants for CCL 3; and (3) Carrying forward CCL 3 contaminants 

allows the agency to focus resources on evaluating contaminants nominated by the public for 

CCL 4 and review new data for CCL 1 or CCL 2 contaminants with previous negative regulatory

determinations.

2. Summary and Evaluation of CCL 4 Nominated Contaminants

a. CCL 4 Nominations Summary 

The agency sought public nominations on May 8, 2012, for contaminants to be 

considered for possible inclusion in the CCL 4 (77 FR 27057 (USEPA, 2012b)). In the notice, 

EPA also requested supporting information that has been made available since the development 

of the CCL 3, or existing information that was not considered for CCL 3, which shows that the 

nominated contaminant may have an adverse effect on people, and occurs or is likely to occur in 

public water systems.
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EPA received nominations for 59 unique contaminants for the CCL 4, including 54 

chemicals and five microbials. Eight contaminants were nominated by more than one nominator. 

Aldicarb, bisphenol A, carbaryl, chlorpyrifos, Toxoplasma gondii, and Microcystin-LR were 

each nominated by two separate nominators. Manganese and perfluorooctanoic acid (PFOA) 

were nominated by three different nominators each. 

Nominations were received from 10 different organizations and/or individuals. The 

agency did not require nominators to provide their name or an affiliated organization. Two 

nominators remained anonymous while providing documentation and rationale for the 

contaminants. Two other individuals identified themselves but did not provide an organization 

affiliation. The organizations that nominated contaminants were:

 American Water Works Association (AWWA), 

 Natural Resources Defense Council, (NRDC), 

 Massachusetts Department of Environmental Protection (MDEP),

 Minnesota Department of Health (MDH),

 New Jersey Department of Environmental Protection (NJDEP), and

 U.S. Department of Agriculture (USDA).

EPA received three general types of nominations:

 specific individual chemicals, 

 specific individual organisms, and 

 groups of contaminants (e.g., Heterotrophic Plate Count (HPC) was considered as a 

group). 
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The AWWA also provided a letter with recommendations for the CCL 4 process. The full 

text of this letter and all of the nomination submittals in their original form can be found at 

http://www.regulations.gov (docket ID: EPA-HQ-OW-2012-0217). Exhibit 2 contains the 

specific contaminants identified in public nominations. A more detailed summary of the 

nominations process is included in the support document “Summary of Nominations for the 

Fourth CCL” (USEPA, 2014e). 

Exhibit 2. Contaminants Nominated for Consideration on the Draft CCL 4:

Nominated Microbial Contaminants

Adenovirus

Heterotrophic Plate Count Bacteria (HPC)

Naegleria fowleri

Toxoplasma gondii

Vibrio cholerae

Nominated Chemical Contaminants

Common Name – Registry Name CASRN

3-chloro-4-dichloromethyl-5-hydroxy2(5H)-furanone 77439-76-0

alpha-Hexachlorocyclohexane 319-84-6

Aldicarb 116-06-3

Alkylphenol mono- to tri-oxylates 68555-24-8

Amoxicillin 26787-78-0

Azinphos-methyl 86-50-0

Bacitracin zinc 1405-89-6
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Common Name – Registry Name CASRN

Bentazone 25057-89-0

Benzyl butyl phthalate 85-68-7

Bisphenol A 80-05-7

Bromoxynil 1689-84-5

Carbaryl 63-25-2

Cesium 137 10045-97-3 

Chlorothalonil 1897-45-6

Chlorpyrifos 2921-88-2

Dibutyl phthalate 84-74-2

Dicamba 1918-00-9

Dichlorvos 62-73-7

Dicofol 115-32-2

Dicyclohexyl phthalate 84-61-7

Diethyl phthalate 84-66-2

Di-isononyl phthalate 28553-12-0

Dimethyl phthalate 131-11-3

Di-n-octyl phthalate 117-84-0

Endosulfan 115-29-7

Fluometuron 2164-17-2

Linezolid 165800-03-3

Linuron 330-55-2

Malathion 121-75-5

Manganese 7439-96-5

Methicillin 61-32-5

Methyl parathion 298-00-0

Methyl tertiary butyl ether (MTBE) 1634-04-4

Microcystin-LR 101043-37-2

Nonylphenol 25154-52-3
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Common Name – Registry Name CASRN

Nonylphenol ethoxylate 9016-45-9

Octylphenol 27193-28-8

Octylphenol ethoxylate 9036-19-5

Oxacillin 66-79-5

Penicillin (multiple CASRNs)

Perfluorooctanoic acid (PFOA) 335-67-1

Permethrin 52645-53-1

Phosmet 732-11-6

Progesterone 57-83-0

Radon 10043-92-2

Spiramycin 8025-81-8

Strontium 90 121831-99-0

Testosterone 58-22-0

Trichlorfon 52-68-6

Triclocarban 101-20-2

Triclosan 3380-34-5

Tylosin 1401-69-0

Vancomycin 1404-90-6

Virginiamycin 11006-76-1

b. Evaluation of Nominated Contaminants and Data Sources

The SDWA specifies that the CCL only include those contaminants without any proposed 

or promulgated NPDWRs. Two nominated contaminants are covered under the existing NPDWR 

for beta photon emitters (40 CFR §141.66 (d)(1)) (i.e., strontium 90 and cesium 137) and 

therefore will not be considered for CCL 4. Radon was also nominated, but is not eligible for 
Page 24 of 40

CCL 4 since a proposed NPDWR has been developed (64 FR 59245, November 2, 1999

(USEPA, 1999). Aldicarb was nominated but is not eligible for CCL 4 since it has an existing 

NPDWR (40 CFR §141.61(c)); (Note, in response to an administrative petition, the agency

issued an administrative stay of the effective date of the maximum contaminant levels (MCLs) 

for aldicarbs).

For the remaining 55 nominated contaminants, EPA reviewed the nominations and 

supporting information provided by nominators to determine if any new data were provided that 

had not been previously evaluated for CCL 3. The agency also collected additional data for the 

nominated contaminants, when it was available, from both CCL 3 data sources and from new 

data sources that were not available at the time of CCL 3. A complete list of references provided 

by nominators can be found in the support document “Summary of Nominations for the Fourth 

CCL” (USEPA, 2014e). A more detailed description of the CCL data sources collected by EPA

may be found in the support document “Data Sources for the CCL 4” (USEPA, 2014c)). If new 

data were available, EPA screened and scored the nominated contaminants using the same 

process as was used in CCL 3. Seven of the nominated contaminants were on CCL 3. Therefore, 

EPA carried forward these seven contaminants to the Draft CCL 4 along with the other CCL 3 

contaminants. The seven contaminants are: perfluorooctanoic acid (PFOA), Microcystin-LR, 

methyl tertiary butyl ether (MTBE), alpha-hexachlorocyclohexane, permethrin, Naegleria 

fowleri, and Adenovirus. Microcystin-LR is included within the group of cyanotoxins in the 

Final CCL 3 and the Draft CCL 4.

Data sources for chemical and microbial contaminants
Page 25 of 40

In addition to the data provided by nominators, and the data EPA collected previously

under CCL 3, EPA collected data for the nominated contaminants from data sources that were 

used for CCL 3 and that had been updated (for a complete list of data sources used in CCL 3, see 

the “Final Contaminant Candidate List 3 Chemicals: Identifying the Universe” document 

(USEPA, 2009a)) and the “Final Contaminant Candidate List 3 Microbes: Screening to the 

PCCL” (USEPA, 2009d)).

For nominated chemicals, occurrence data was collected from updated CCL 3 data sources 

including: 

 2006 production data collected in the Chemical Update System (CUS) under the 

Inventory Update Rule (IUR),

 2010 data from the Toxics Release Inventory (TRI), 

 2003-2009 data from the U.S. Department of Agriculture’s (USDA) Pesticide Data 

Program (PDP), and

 EPA’s Storage and Retrieval (STORET) data as of January 2013. 

Additional occurrence data for the nominated chemicals was collected from data sources 

that are new since the CCL 3 including: 

 USGS studies that focused on contaminant occurrence in source waters for public water 

systems (Hopple et al., 2009, and Kingsbury et al., 2008) and water quality in publicsupply wells (Toccalino et al., 2010); 

 Individual State public water supply data provided to EPA during the second Six-Year 

Review of regulated contaminants (for the time period covering 1998-2005) from States 

including: CA, FL, IL, NC, OH, Region 9 Tribes, SD, TX, and WI; 
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 Data from The California State Water Resources Control Board’s Groundwater Ambient 

Monitoring Assessment (GAMA) program; and 

 EPA also evaluated new data from a literature review of published studies on 

pharmaceuticals, personal care products, and other contaminants. 

In addition to health effects data provided by the nominators, EPA searched for health 

effects data for the nominated chemicals from data sources used in CCL 3 that may have been 

updated including:

 EPA’s Integrated Risk Information System (IRIS) program, 

 EPA’s Office of Pesticide Programs (OPP), 

 the Agency for Toxic Substances and Disease Registry (ATSDR), 

 California EPA (Office of Environmental Health Hazard Assessment), 

 Institute of Medicine (IOM), 

 the National Toxicology Program (NTP), and 

 the World Health Organization (WHO). 

EPA also considered new or updated health effects information contained in the agency’s

Office of Superfund Remediation and Technology Innovation (OSRTI) Provisional Peer 

Reviewed Toxicity Values (PPRTVs).

For microbial contaminants, EPA evaluated waterborne disease outbreak data, 

occurrence, and health effects data from data sources used in CCL 3 that have been updated 

(Murray et al., 2011; CDC, 2008; CDC, 2011). EPA also collected and evaluated information

for microbial contaminants from data sources that are new since publication of the Final CCL 3.
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A more detailed description of the data sources used to evaluate contaminants for CCL 4 

can be found in the support document “Data Sources for the CCL 4” (USEPA, 2014c) available 

at www.regulations.gov (Docket ID: EPA-HQ-OW-2012-0217).

c. Outcomes for the CCL 4 Nominated Contaminants

EPA evaluated the nominated contaminants (see Exhibit 2) using the best available health 

effects and occurrence data and the same process for screening and scoring contaminants that 

was used for CCL 3. Forty-three of the nominated chemicals were included in the CCL 4 

Universe. Forty of the nominated chemicals were previously included in the CCL 3 Universe and 

were carried forward to the CCL 4 Universe. In addition to these forty, EPA has added three

nominated chemicals (i.e., octylphenol ethoxylate, oxacillin, and virginiamycin) to the CCL 4 

Universe based on health effects and/or occurrence data that is newly available since the 

development of the CCL 3. EPA screened all of the nominated chemicals in the CCL 4 Universe 

according to the screening criteria developed for CCL 3, and based on that evaluation, twenty of 

the nominated chemicals were included in the PCCL 4. Eighteen of those 20 chemicals were also

included in the PCCL 3, and EPA added two new chemicals (manganese and nonylphenol) to the 

PCCL 4. The data used to screen the nominated chemicals from the CCL 4 Universe to the 

PCCL 4 can be found in the “Screening Document for the Draft PCCL 4 Nominated

Contaminants” (USEPA, 2014d). EPA further evaluated the nominated chemicals on the PCCL 4 

based on the classification process developed in CCL 3 and determined that manganese and 

nonylphenol should be added to the Draft CCL 4 (in addition to the chemicals carried forward 

from the CCL 3 to the Draft CCL 4) based on new health and/or occurrence information that 

warrants further evaluation. The data that was used to further evaluate the nominated 
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contaminants from the PCCL 4, and to select those that were included in the Draft CCL 4 can be 

found in the “Contaminant Information Sheets for the Draft PCCL 4 Nominated Contaminants” 

(USEPA, 2014b).

Manganese is an element that naturally occurs in oxide forms and in combinations with 

other elements in many minerals. Small amounts, found in foods, are an essential nutrient for 

humans and animals. Manganese ores are used in a variety of applications in the US. Its principal 

use is in steel production to improve hardness, stiffness, and strength (ATSDR, 2012). In 2003 

and as part of the CCL 1 Regulatory Determination process, EPA made a negative regulatory

determination for manganese based on the health and occurrence data available at that time. 

However, CCL 4 nominators cited more than 20 recent studies that indicate concern for 

neurological effects in children and infants exposed to excess manganese, which were not 

available at the time manganese was considered for Regulatory Determination 1 or CCL 3. In 

addition, new monitoring studies from USGS and drinking water monitoring information from 

several States support an earlier survey (i.e., the National Inorganics and Radionuclides Survey) 

that indicates manganese is known to occur in drinking water. EPA believes the new health 

effects information and additional occurrence data merit listing manganese in the Draft CCL 4.

Nonylphenol is used in the preparation of lubricating oil additives, resins, plasticizers, 

and antioxidants for plastics and rubber. Additionally, sixty percent of nonylphenol is used in the 

production of nonylphenol ethoxylates, which are found in detergents and used in the treatment 

of textiles. Nonylphenol was previously considered for CCL 3. It was included in the CCL 3 

Universe, but was not included in the PCCL 3 or CCL 3. Updated health and occurrence data 

(since the development of the CCL 3) are now available for nonylphenol, and these data (as 
Page 29 of 40

follows) were considered in evaluating nonylphenol for the Draft CCL 4. Nonylphenol and some 

of its degradation products have been found to have estrogenic activity in rats and mice (WHO, 

2004). Monitoring data are available from a USGS National Reconnaissance monitoring study of 

ambient water (Kolpin et al., 2002). EPA believes this updated health data and additional 

occurrence data show that nonylphenol is anticipated to occur in PWSs and has potential adverse 

health effects, and therefore merits listing on the Draft CCL 4.

EPA considered adding dicofol to the Draft CCL 4; however, both of the most recent 

manufacturers of the pesticide ceased all production as of May 17, 2011, and agreed to an EPA 

registration cancellation, which effectively prohibits all labeled uses of existing stocks after 

October 31, 2016. Use of dicofol has declined significantly in recent years. The chemical 

properties of dicofol indicate that it is has low mobility in water because it is expected to adsorb

to organic matter in soil and sediment and it has moderately low solubility in water. Therefore,

EPA did not list dicofol on the Draft CCL 4 because it is not known or anticipated to occur in 

drinking water due to its low mobility. Additionally, the registration cancellation, which will 

prohibit use of existing stocks beyond October 2016, is expected to further lessen any potential

occurrence in drinking water. 

EPA evaluated the microbial contaminants nominated (see Exhibit 2) for the CCL 4 using 

the same process developed for the CCL 3. A general description of the microbial contaminant 

evaluation process is provided below. The microbial CCL 3 Universe was defined by EPA as all 

known human pathogens. Taylor et al. (2001) was used as the basis of the microbial CCL 3 

Universe, which includes a list of 1,415 known human pathogens. EPA added 10 additional 

microbes to the CCL 3 Universe based on CCL 3 public nominations and other available data,
Page 30 of 40

thus bringing the total number of microbes in the CCL 3 Universe to 1,425. More detailed 

information about the selection of the CCL 3 Universe for microbial contaminants can be found 

in the support document “Final CCL 3 Microbes: Identifying the Universe” (USEPA, 2009b).

The microbes in the CCL 3 Universe were subsequently screened into the PCCL 3 by

applying 12 screening criteria to narrow the Universe of all human pathogens to just those 

pathogens that could be transmitted through drinking water. More detailed information on the 

screening process developed under CCL 3 for the microbial contaminants can be found in the 

support document “Final CCL 3 Microbes: Screening to the PCCL” (USEPA, 2009d).

All the microbes nominated for the CCL 4, with the exception of Heterotrophic Plate 

Count (HPC) bacteria, were already included in both the CCL 3 Universe and PCCL 3. Thus, 

they were carried forward to the CCL 4 Universe and PCCL 4, respectively. 

EPA reviewed new and/or updated sources of information for the nominated microbes on 

the PCCL 4 (i.e., Adenovirus, Naegleria fowleri, Toxoplasma gondii and Vibrio cholerae), and 

determined that there was no new data that would change the scores or listing decisions for these 

contaminants. 

Vibrio cholerae and Toxoplasma gondii will remain on the Draft PCCL 4 because there is 

no new data that would change the CCL 3 scores or listing decisions for these contaminants. 

Naegleria fowleri and Adenovirus were on the Final CCL 3 and are therefore being carried 

forward to the Draft CCL 4, along with the other microbes included on the Final CCL 3. A 

detailed description of the CCL 3 scoring protocol for microbes can be found in the support 

document “Final CCL 3 Microbes: PCCL to CCL Process” (USEPA, 2009c). The data used to 
Page 31 of 40

further evaluate the nominated microbes on the PCCL 4 can be found in the “Contaminant 

Information Sheets for the Draft PCCL 4 Nominated Contaminants” (USEPA, 2014b).

The group of HPC bacteria was nominated for CCL 4, but EPA is not including it on the 

Draft CCL 4. HPC may include both pathogenic and harmless bacteria. However, available 

epidemiological evidence shows no relationship between gastrointestinal illness and HPC 

bacteria in drinking water (Calderon, 1988; Calderon and Mood, 1991; Payment et al., 1997; 

WHO, 2003). Thus, EPA considers the potential health risk of HPC bacteria in drinking water as 

likely negligible and is not including HPC on the Draft CCL 4. In addition, HPC bacteria are 

addressed under the Surface Water Treatment Rule as a treatment technique (TT) where they can 

be monitored in lieu of a disinfectant residual.

3. Evaluation of Previous Negative Regulatory Determinations

EPA evaluated the 20 contaminants from CCL 1 and CCL 2 for which the agency made

negative regulatory determinations. EPA collected and evaluated new or updated data for the 

previous negative regulatory determinations, if data were available, from the data sources listed 

in Section II.E.2(b) “Evaluation of the Nominated Contaminants and Data Sources.” Since 

regulatory determinations for the CCL 3 contaminants were recently made using the best 

available data, EPA did not include the CCL 3 regulatory determinations in this evaluation. EPA 

is adding manganese to the Draft CCL 4, as discussed above in subsection 2 of this section, titled 

“Nominations and Evaluation for CCL 4 Contaminants.” The agency concluded there was not 

sufficient new information for any of the other 19 contaminants with previous negative 

regulatory determinations to justify including them on the Draft CCL 4. A listing of previous 

negative regulatory determinations is included in Sections II.D.2 and II.D.4.
Page 32 of 40

F. What is on EPA’s Draft CCL 4?

The Draft CCL 4 includes 100 chemicals and 12 microbes. 

Exhibit 3. Draft Contaminant Candidate List 4:

Microbial Contaminants

Pathogens

Adenovirus

Caliciviruses

Campylobacter jejuni

Enterovirus

Escherichia coli (0157)

Helicobacter pylori

Hepatitis A virus

Legionella pneumophila

Mycobacterium avium

Naegleria fowleri

Salmonella enterica

Shigella sonnei

Chemical Contaminants4

Common Name – Registry Name CASRN

1,1,1,2-Tetrachloroethane 630-20-6

 

4 Contaminants on the Final CCL 3 but not on the Draft CCL 4 are: 1, 3-dinitrobenzene, 

dimethoate, perchlorate, strontium, terbufos, and terbufos sulfone.
Page 33 of 40

Common Name – Registry Name CASRN

1,1-Dichloroethane 75-34-3

1,2,3-Trichloropropane 96-18-4

1,3-Butadiene 106-99-0

1,4-Dioxane 123-91-1

17 alpha-Estradiol 57-91-0

1-Butanol 71-36-3

2-Methoxyethanol 109-86-4

2-Propen-1-ol 107-18-6

3-Hydroxycarbofuran 16655-82-6

4,4'-Methylenedianiline 101-77-9

Acephate 30560-19-1

Acetaldehyde 75-07-0

Acetamide 60-35-5

Acetochlor 34256-82-1

Acetochlor ethanesulfonic acid (ESA) 187022-11-3

Acetochlor oxanilic acid (OA) 194992-44-4

Acrolein 107-02-8

Alachlor ethanesulfonic acid (ESA) 142363-53-9

Alachlor oxanilic acid (OA) 171262-17-2

Alpha-Hexachlorocyclohexane 319-84-6

Aniline 62-53-3

Bensulide 741-58-2

Benzyl chloride 100-44-7

Butylated hydroxyanisole 25013-16-5

Captan 133-06-2

Chlorate 14866-68-3

Chloromethane (Methyl chloride) 74-87-3

Clethodim 110429-62-4

Cobalt 7440-48-4

Cumene hydroperoxide 80-15-9

Cyanotoxins (Microcystin-LR, 

Cylindrospermopsin, Anatoxin-a) N/A

Dicrotophos 141-66-2

Dimethipin 55290-64-7

Disulfoton 298-04-4

Diuron 330-54-1
Page 34 of 40

Common Name – Registry Name CASRN

Equilenin 517-09-9

Equilin 474-86-2

Erythromycin 114-07-8

Estradiol (17-beta estradiol) 50-28-2

Estriol 50-27-1

Estrone 53-16-7

Ethinyl Estradiol (17-alpha Ethinyl Estradiol) 57-63-6

Ethoprop 13194-48-4

Ethylene glycol 107-21-1

Ethylene oxide 75-21-8

Ethylene thiourea 96-45-7

Fenamiphos 22224-92-6

Formaldehyde

50-00-0

Germanium 7440-56-4

Halon 1011 (bromochloromethane) 74-97-5

HCFC-22 75-45-6

Hexane 110-54-3

Hydrazine 302-01-2

Manganese 7439-96-5

Mestranol 72-33-3

Methamidophos 10265-92-6

Methanol 67-56-1

Methyl bromide (Bromomethane) 74-83-9

Methyl tertiary butyl ether (MTBE) 1634-04-4

Metolachlor 51218-45-2

Metolachlor ethanesulfonic acid (ESA) 171118-09-5

Metolachlor oxanilic acid (OA) 152019-73-3

Molinate 2212-67-1

Molybdenum 7439-98-7

Nitrobenzene 98-95-3

Nitroglycerin 55-63-0

N-Methyl-2-pyrrolidone 872-50-4

N-nitrosodiethylamine (NDEA) 55-18-5

N-nitrosodimethylamine (NDMA) 62-75-9

N-nitroso-di-n-propylamine (NDPA) 621-64-7
Page 35 of 40

Common Name – Registry Name CASRN

N-Nitrosodiphenylamine 86-30-6

N-nitrosopyrrolidine (NPYR) 930-55-2

Nonylphenol 25154-52-3

Norethindrone (19-Norethisterone) 68-22-4

n-Propylbenzene 103-65-1

o-Toluidine 95-53-4

Oxirane, methyl75-56-9

Oxydemeton-methyl 301-12-2

Oxyfluorfen 42874-03-3

Perfluorooctane sulfonic acid (PFOS) 1763-23-1

Perfluorooctanoic acid (PFOA) 335-67-1

Permethrin 52645-53-1

Profenofos 41198-08-7

Quinoline 91-22-5

RDX (Hexahydro-1,3,5-trinitro-1,3,5-triazine) 121-82-4

sec-Butylbenzene 135-98-8

Tebuconazole 107534-96-3

Tebufenozide 112410-23-8

Tellurium 13494-80-9

Thiodicarb 59669-26-0

Thiophanate-methyl 23564-05-8

Toluene diisocyanate 26471-62-5

Tribufos 78-48-8

Triethylamine 121-44-8

Triphenyltin hydroxide (TPTH) 76-87-9

Urethane 51-79-6

Vanadium 7440-62-2

Vinclozolin 50471-44-8

Ziram 137-30-4

III. Request for Comment

The purpose of this notice is to present the Draft CCL 4 and seek comment on the 

contaminants selected for the Draft CCL 4, including any supporting data that can be used in 

developing the Final CCL 4. Data obtained and evaluated for developing the Draft CCL 4 may
Page 36 of 40

be found in the CCL 4 support documents located in the docket for this notice. Specifically, the 

agency is also asking for public comments on including manganese and nonylphenol in the CCL

4 and any additional data and information on manganese and nonylphenol health effects and 

concentrations in finished or ambient water. EPA is also seeking comment on ways the agency

can improve or refine the selection process developed for CCL 3, and will take these comments 

into consideration when developing future CCLs. Information and comments submitted will be 

considered in determining the Final CCL 4, as well as in the development of future CCLs and in 

the agency's efforts to set drinking water priorities in the future.

IV. EPA’s Next Steps

Between now and the publication of the Final CCL 4, the agency will evaluate comments 

received during the public comment period for this notice, consult with the agency’s Science 

Advisory Board, and revise the CCL 4, as appropriate. 

V. References

ATSDR. 2012. ToxFAQs for Manganese. Atlanta, GA. October, 2012. Available on the Internet 

at: http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=101&tid=23.

Calderon, R.L. 1988. Bacteria Colonizing Point-of-Entry Granular Activated Carbon filters and 

their Relationship to Human Health. EPA CR-813978-01-0, US Environmental Protection 

Agency, Washington, DC.

Calderon, R.L. and Mood, E.W. 1991. Bacteria Colonizing Point-of-Use Granular Activated 

Carbon Filters and their Relationship to Human Health. EPA CR 811904-01-0, US 

Environmental Protection Agency, Washington, DC.

CDC. 2008. Surveillance for Waterborne Disease and Outbreaks Associated with Drinking 

Water and Water not Intended for Drinking — United States, 2005-2006. MMWR 57 (SS-9). 

CDC. 2011. Surveillance for Waterborne Disease and Outbreaks Associated with Drinking 

Water - United States, 2007-2008. MMWR 60 (SS-12).
Page 37 of 40

Code of Federal Regulations. Revised as of July 1, 2012. Title 40 Protection of the Environment. 

Subpart G—National Primary Drinking Water Regulations: Maximum Contaminant Levels and 

Maximum Residual Disinfectant Levels. Section 141.61 (c).

Code of Federal Regulations. Revised as of July 1, 2012. Title 40 Protection of the Environment. 

Subpart G—National Primary Drinking Water Regulations: Maximum Contaminant Levels and 

Maximum Residual Disinfectant Levels. Section 141.66 (d)(1).

Hopple, J.A., G.C. Delzer, and J.A. Kingsbury. 2009. Anthropogenic Organic Compounds in 

Source Water of Selected Community Water Systems that Use Groundwater, 2002–05. U.S. 

Geological Survey Scientific Investigations Report 2009–5200. 74 pp. Available on the Internet 

at: http://pubs.usgs.gov/sir/2009/5200/pdf/sir2009-5200.pdf.

Kingsbury, J.A., G.C. Delzer, and J.A. Hopple. 2008. Anthropogenic Organic Compounds in 

Source Water of Nine Community Water Systems that Withdraw from Streams, 2002–05. U.S. 

Geological Survey Scientific Investigations Report 2008–5208. 66 pp. Available on the Internet 

at: http://pubs.usgs.gov/sir/2008/5208/pdf/sir2008-5208.pdf.

Kolpin, D. W., E. T. Furlong, M. T. Meyer, E. M. Thurman, S. D. Zaugg, L. B. Barber, and H. T. 

Buxton. 2002. Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in U.S. 

Streams, 1999-2000: A National Reconnaissance. Environmental Science and Technology, v. 36, 

no. 6.

Murray, P. R., E. J. Baron, J. H. Jorgensen, M. L. Landry, and M. A. Pfaller (ed.). 2011. Manual 

of Clinical Microbiology, 10th Edition, ASM Press, Washington, DC. 

National Drinking Water Advisory Council (NDWAC). 2004. National Drinking Water 

Advisory Council Report on the CCL Classification Process to the U. S. Environmental 

Protection Agency, May 19, 2004.

National Research Council (NRC). 2001. Classifying Drinking Water Contaminants for 

Regulatory Consideration. National Academy Press, Washington, DC.

Payment, P., J. Siemiatycki, L. Richardson, G. Renaud, E. Franco, and M. Prevost. 1997. A 

prospective epidemiological study of gastrointestinal health effects due to the consumption of 

drinking water. Int. J. Environ. Health Res. (7): 5-31.

Taylor, L.H., S.M. Latham, and M.E. Woolhouse. 2001. Risk Factors for Human Disease 

Emergence (Appendix A). Phil. Trans. R. Soc. Lond. B. Vol 256, pp. 983-989.

Toccalino, P.L., J.E. Norman, and K.J. Hitt. 2010. Quality of Source Water from Public-supply

Wells in the United States, 1993–2007. U.S. Geological Survey Scientific Investigations Report 

2010-5024. 206 pp. Available on the Internet at: http://pubs.usgs.gov/sir/2010/5024/.
Page 38 of 40

USEPA, 1998. Announcement of the Drinking Water Contaminant Candidate List; Notice. 

Federal Register. Vol. 63, No. 40. p. 10273, March 2, 1998.

USEPA, 1999. National Primary Drinking Water Regulations; Radon-222; Proposed Rule. 

Federal Register. Vol. 64, No. 211. p. 59245, November 2, 1999.

USEPA. 2003. Announcement of Regulatory Determinations for Priority Contaminants on the 

Drinking Water Contaminant Candidate List. Federal Register. Vol. 68, No. 138. p. 42898, July

18, 2003.

USEPA. 2005. Notice - Drinking Water Contaminant Candidate List 2; Final Notice. Federal 

Register. Vol. 70, No. 36. p. 9071, February 24, 2005.

USEPA. 2008a. Drinking Water Contaminant Candidate List 3 - Draft. Federal Register. Vol. 73, 

No. 35. p. 9628, February 21, 2008.

USEPA. 2008b. Drinking Water: Regulatory Determinations Regarding Contaminants on the 

Second Drinking Water Contaminant Candidate List. Federal Register. Vol. 73, No. 174. p. 

44251, July 30, 2008.

USEPA. 2009a. Final Contaminant Candidate List 3 Chemicals: Identifying the Universe. EPA 

815-R09-006. August, 2009. 

USEPA. 2009b. Final Contaminant Candidate List 3 Microbes: Identifying the Universe. EPA 

815-R-09-004. August, 2009.

USEPA. 2009c. Final Contaminant Candidate List 3 Microbes: PCCL to CCL Process. EPA 

815-R-09-009. August, 2009.

USEPA. 2009d. Final Contaminant Candidate List 3 Microbes: Screening to the PCCL. EPA 

815-R-09-0005. August, 2009.

USEPA. 2009e. Drinking Water Contaminant Candidate List 3 - Final. Federal Register. Vol. 74, 

No. 194. p. 51850, October 8, 2009.

USEPA. 2011. Drinking Water: Regulatory Determination on Perchlorate. Federal Register. 

Vol. 76, No. 29. p. 7762, February 11, 2011.

USEPA. 2012a. Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) 

for Public Water Systems. Federal Register. Vol. 77, No. 85. p. 26071, May 2, 2012.
Page 39 of 40

USEPA. 2012b. Request for Nominations of Drinking Water Contaminants for the Fourth 

Contaminant Candidate List. Federal Register. Vol. 77, No. 89. p. 27057, May 8, 2012.

USEPA. 2014a. Announcement of Preliminary Regulatory Determination for Contaminants on 

the Third Drinking Water Contaminant Candidate List. Federal Register. Vol. 79, No. xx, p. 

xxxxx, Month, 2014.

USEPA. 2014b. Contaminant Information Sheets for the Draft PCCL 4 Nominated 

Contaminants. EPA xxx-Rxx-xxx. Month, 2014.

USEPA. 2014c. Data Sources for the CCL 4. EPA xxx-Rxx-xxx. Month, 2014.

USEPA. 2014d. Screening Document for the Draft PCCL 4 Nominated Contaminants. EPA 

xxx-Rxx-xxx. Month, 2014.

USEPA. 2014e. Summary of Nominations for the Fourth CCL. EPA xxx-Rxx-xxx. Month, 

2014. 

WHO. 2003. Emerging Issues in Water and Infectious Disease Series: Heterotrophic Plate 

Counts and Drinking-water Safety. ed. J. Bartram, J. Cotruvo, M. Exner, C. Fricker, and A. 

Glasmacher. IWA Publishing, London, UK. P. 119 – 122.

WHO. 2004. Integrated Risk Assessment: Nonylphenol Case Study. ed. D. Bontje, J. Hermens, 

T. Vermeire, and T. Damstra. 63 pp. December, 2004. Available on the Internet at: 

http://www.who.int/ipcs/methods/Nonylphenol.pdf.

Dated 

Kenneth J. Kopocis,

Deputy Assistant Administrator, Office of Water.
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