[Federal Register Volume 74, Number 194 (Thursday, October 8, 2009)]
[Notices]
[Pages 51850-51862]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-24287]
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ENVIRONMENTAL PROTECTION AGENCY
[EPA-HQ-OW-2007-1189 FRL-8963-6]
RIN 2040-AD99
Drinking Water Contaminant Candidate List 3--Final
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: The Environmental Protection Agency is publishing the third
Contaminant Candidate List (CCL 3) since the Safe Drinking Water Act
(SDWA) amendments of 1996. The CCL 3 is a list of contaminants that are
currently not subject to any proposed or promulgated national primary
drinking water regulations, that are known or anticipated to occur in
public water systems, and which may require regulation under SDWA.
Today's final CCL 3 includes 104 chemicals or chemical groups and 12
microbiological contaminants.
ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OW-2007-1189. All documents in the docket are listed on
http://www.regulations.gov. Although listed in the index, some
information is not publicly available. For example, confidential
business information or other information whose disclosure is
restricted by statute is not publicly available. Certain other
material, such as copyrighted material, is not placed on the Internet
and is only in hard copy form. Publicly available docket materials are
available either electronically through http://www.regulations.gov or
in hard copy at the Water Docket, EPA/DC, EPA West, Room 3334, 1301
Constitution Ave., NW., Washington, DC. 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 Thomas Carpenter, Office of Ground Water and
Drinking Water, Standards and Risk Management Division, at (202) 564-
4885 or e-mail [email protected]. For information on microbial
contaminants contact Tracy Bone, Office of Ground Water and Drinking
Water, at (202) 564-5257 or e-mail [email protected]. For general
information contact the EPA Safe Drinking Water Hotline at (800) 426-
4791 or e-mail: [email protected].
Abbreviations and Acronyms
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
CERCLA--Comprehensive Environmental Response, Compensation, and
Liability Act
CFR--Code of Federal Regulations
CSF--Cancer Slope Factor
DBP--disinfection byproduct
EPA--United States Environmental Protection Agency
ESA--ethanesulfonic acid
FDA--United States Food and Drug Administration
FIFRA--Federal Insecticide, Fungicide, and Rodenticide Act
FR--Federal Register
HRL--Health Reference Level
ICR--Information Collection Request
IUR--Inventory Update Rule
MCL--maximum contaminant level
MCLG--maximum contaminant level goal
NCFAP--National Center for Food and Agricultural Policy
NDWAC--National Drinking Water Advisory Council
NDMA--N-nitrosodimethylamine
NIRS--National Inorganic Radiological Survey
NRC--National Academies of Science's National Research Council
NPDWR--national primary drinking water regulation
OPP--Office of Pesticide Programs
PCCL--Preliminary CCL
PFOA--perfluorooctanoic acid
PFOS--perfluorooctane sulfonic acid
[[Page 51851]]
PWS--public water system
RAISHE--Risk Assessment Information System, Health Effects
RDX- Cyclotrimethylenetrinitramine
RfD--reference dose
RTECS--Registry of Toxic Effects for Chemical Substances
SAB--EPA Science Advisory Board
SDWA--Safe Drinking Water Act
TRI--Toxics Release Inventory
TNT--2, 4, 6-trinitrotoluene
UCMR--Unregulated Contaminant Monitoring Regulation
UCMR 1--First Unregulated Contaminant Monitoring Regulation
UCMR 2--Second Unregulated Contaminant Monitoring Regulation
UCM R1/2--Unregulated Contaminant Monitoring Round \1/2\
U.S.--United States of America
USGS--United States Geological Survey
WBDO--waterborne disease outbreak
WHO--World Health Organization
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does This Action Impose Any Requirements on My Public Water
System?
B. What Is the Purpose of this Action?
C. SDWA Risk Management Provisions
1. Contaminant Candidate List 3
2. Regulatory Determinations
3. Unregulated Contaminant Monitoring
II. What is on EPA's Drinking Water Contaminant Candidate List 3?
III. What Comments did EPA Receive on the Draft CCL 3 and How did
the Agency Respond?
A. Advisory from the EPA Science Advisory Board (SAB)
B. Chemical Contaminants
1. Pesticides and Degradates
2. Cancelled Pesticides
3. Perfluorinated Compounds
4. Pharmaceuticals
5. Perchlorate
6. Disinfection Byproducts
C. Microbial Contaminants
1. Using the CDC WBDO's as a Scoring Criteria
2. Mycobacterium avium
3. Vibrio cholerae and Entamoeba hystolitica
D. Other comments
1. Data Sources for the Contaminant Candidate Lists
2. Contaminant Candidate List and Unregulated Contaminants
Monitoring Regulation
IV. Data Needs for CCL 3 Contaminants
A. Chemical Contaminants
1. Health Effects
2. Occurrence
3. Analytical Methods
B. Microbial Contaminants
V. Next Steps/Future Contaminant Candidate Lists
VI. References
I. General Information
A. Does This Action Impose Any Requirements on My Public Water System?
The final Contaminant Candidate List 3 (CCL 3) will not impose any
requirements on anyone. Instead, this action notifies interested
parties of the availability of U.S. EPA's final CCL 3, and provides
information on the Agency's next steps to evaluate these contaminants.
B. What Is the Purpose of This Action?
The purpose of this action is to present the final CCL 3, a summary
of the comments received on the draft CCL 3, and a description of the
Agency's process for identifying contaminants to be placed on the list.
Pursuant to section 1412(b)(1)(B)(i) of SDWA, as amended in 1996, EPA
is required to publish a list of contaminants (1) that are currently
unregulated, (2) that are known or anticipated to occur in public water
systems, and (3) which may require regulations under the Safe Drinking
Water Act (SDWA). This section briefly summarizes the statutory
requirements for CCL 3, and related activities surrounding the
contaminants included on the final CCL 3.
C. SDWA Risk Management Provisions
1. Contaminant Candidate List 3
SDWA section 1412(b)(1) requires that in the development of the
CCL, EPA consider specific data sources and include the scientific
community. EPA must evaluate substances identified in section 101(14)
of the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) of 1980 and substances registered as pesticides
under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
SDWA also requires the Agency to consider the National Contaminant
Occurrence Database established under section 1445(g) of SDWA. SDWA
directs the Agency to consult with the scientific community, including
the Science Advisory Board (SAB). In addition it 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.
EPA interprets the criterion that contaminants are known or
anticipated to occur in public water systems broadly. In evaluating
this criterion, EPA considers not only public water system monitoring
data, but also data on ambient concentrations in surface and ground
waters, and releases to the environment (e.g., Toxics Release
Inventory). While such data may not establish conclusively that
contaminants are known to occur in public water systems, EPA believes
these data are sufficient to anticipate that contaminants may occur in
public water systems and to place them on the CCL. Once contaminants
have been placed on the CCL, EPA identifies if there are any additional
data needs, including gaps in occurrence data.
In selecting contaminants for the CCL 3, each of the above
requirements was met. The Agency considered adverse health effects that
may pose a greater risk to life stages and other sensitive groups which
represent a meaningful portion of the population. Adverse health
effects associated with infants, children, pregnant women, the elderly,
and individuals with a history of serious illness were evaluated for
both chemicals and microbes.
2. Regulatory Determinations
SDWA section 1412(b)(1) requires EPA to determine whether to
regulate at least five contaminants from the CCL every five years. SDWA
specifies that EPA shall regulate a contaminant if the Administrator
determines that:
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.
EPA interprets these criteria as more rigorous than what is used to
place contaminants on the CCL. Section IV of this notice presents the
current data needs for regulatory determination for the CCL 3
contaminants.
If EPA makes a determination that a national primary drinking water
regulation is needed, then the Agency has 24 months to publish a
proposed Maximum Contaminant Level Goal (MCLG) \1\ and a proposed
National Primary Drinking Water Rule (NPDWR).\2\ After the proposal,
the Agency has 18 months to publish a final
[[Page 51852]]
MCLG and promulgate a final NPDWR (SDWA 1412(b)(1)(E)).\3\
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\1\ An 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 CFR 141.2).
\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.
\3\ The statute authorizes a nine month extension of this
promulgation date.
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3. Unregulated Contaminant Monitoring
SDWA provides EPA with the authority to require all large and a
subset of small systems to monitor for up to 30 unregulated
contaminants every five years under the Unregulated Contaminant
Monitoring Regulation (UCMR). The second unregulated contaminant
monitoring rule (UCMR 2), which was promulgated on January 4, 2007 (72
FR 367; USEPA, 2007a), requires monitoring for several pesticides and
pesticide degradates, five polybrominated diphenyl ether (PBDE) flame
retardants, a group of nitrosamines, and two munitions (TNT and RDX).
All of the chemicals on UCMR 2 were included among the contaminants
evaluated for CCL 3.
Data collected under the UCMR are an important source of occurrence
information for both the CCL and Regulatory Determination processes.
There is an additional discussion of the relationship between CCL and
UCMR in Section III. D of this Federal Register (FR) notice.
II. What Is on EPA's Drinking Water Contaminant Candidate List 3?
The draft CCL 3 was published on February 21, 2008 (73 FR 9628;
USEPA 2008a), and included 93 chemicals or chemical groups and 11
microbiological contaminants. EPA provided information and sought
comment on its efforts to expand and strengthen the underlying CCL
listing process, the draft list, and EPA's efforts to improve the
contaminant selection process for future CCLs.
In developing the draft CCL 3, EPA implemented a new process from
that used for CCL 1 and CCL 2. This new process builds on evaluations
from previous CCLs, and was based on substantial expert input and
recommendations from various groups, including the National Academy of
Science's National Research Council (NRC) and the National Drinking
Water Advisory Council (NDWAC). This process is summarized in the draft
CCL 3 FR notice.
In general, the criteria for including a contaminant on the CCL
consisted of determining whether the occurrence or anticipated
occurrence of a contaminant was likely at levels of concern to human
health. The draft CCL 3 notice solicited input from the public, and
specifically requested comments on (1) the approach EPA used to create
the list; (2) contaminants on the list; and (3) on specific
contaminants such as pharmaceuticals, perfluorinated compounds, and
microbes.
The final CCL 3 includes 104 chemicals or chemical groups and 12
microbiological contaminants (Exhibit 1). The list includes, among
others, pesticides, biological toxins, disinfection byproducts,
chemicals used in commerce, and waterborne pathogens. The Agency
considered the best available data and information on health effects
and occurrence to evaluate 7,500 unregulated contaminants and selected
116 candidates for the final CCL 3, which have the potential to present
health risks through drinking water exposure.
Exhibit 1. Final Contaminant Candidate List 3:
Chemical Contaminants
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CASRN Common name--registry name
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630206.................................... 1,1,1,2-Tetrachloroethane.
75343..................................... 1,1-Dichloroethane.
96184..................................... 1,2,3-Trichloropropane.
106990.................................... 1,3-Butadiene.
99650..................................... 1,3-Dinitrobenzene.
123911.................................... 1,4-Dioxane.
57910..................................... 17 alpha-Estradiol.
71363..................................... 1-Butanol.
109864.................................... 2-Methoxyethanol.
107186.................................... 2-Propen-1-ol.
16655826.................................. 3-Hydroxycarbofuran.
101779.................................... 4,4'-Methylenedianiline.
30560191.................................. Acephate.
75070..................................... Acetaldehyde.
60355..................................... Acetamide.
34256821.................................. Acetochlor.
187022113................................. Acetochlor ethanesulfonic
acid (ESA).
184992444................................. Acetochlor oxanilic acid
(OA).
107028.................................... Acrolein.
142363539................................. Alachlor ethanesulfonic acid
(ESA).
171262172................................. Alachlor oxanilic acid (OA).
319846.................................... Alpha-Hexachlorocyclohexane.
62533..................................... Aniline.
741582.................................... Bensulide.
100447.................................... Benzyl chloride.
25013165.................................. Butylated hydroxyanisole.
133062.................................... Captan.
14866683.................................. Chlorate.
74873..................................... Chloromethane (Methyl
chloride).
110429624................................. Clethodim.
7440484................................... Cobalt.
80159..................................... Cumene hydroperoxide.
NA........................................ Cyanotoxins.
141662.................................... Dicrotophos.
55290647.................................. Dimethipin.
60515..................................... Dimethoate.
298044.................................... Disulfoton.
330541.................................... Diuron.
517099.................................... Equilenin.
474862.................................... Equilin.
114078.................................... Erythromycin.
50282..................................... Estradiol (17-beta
estradiol).
50271..................................... Estriol.
53167..................................... Estrone.
57636..................................... Ethinyl Estradiol (17-alpha
Ethynyl Estradiol).
13194484.................................. Ethoprop.
107211.................................... Ethylene glycol.
75218..................................... Ethylene oxide.
96457..................................... Ethylene thiourea.
22224926.................................. Fenamiphos.
50000..................................... Formaldehyde.
7440564................................... Germanium.
74975..................................... Halon 1011
(bromochloromethane).
75456..................................... HCFC-22.
110543.................................... Hexane.
302012.................................... Hydrazine.
72333..................................... Mestranol.
10265926.................................. Methamidophos.
67561..................................... Methanol.
74839..................................... Methyl bromide
(Bromomethane).
1634044................................... Methyl tert-butyl ether.
51218452.................................. Metolachlor.
171118095................................. Metolachlor ethanesulfonic
acid (ESA).
152019733................................. Metolachlor oxanilic acid
(OA).
2212671................................... Molinate.
7439987................................... Molybdenum.
98953..................................... Nitrobenzene.
55630..................................... Nitroglycerin.
872504.................................... N-Methyl-2-pyrrolidone.
55185..................................... N-Nitrosodiethylamine
(NDEA).
62759..................................... N-nitrosodimethylamine
(NDMA).
621647.................................... N-Nitroso-di-n-propylamine
(NDPA).
86306..................................... N-Nitrosodiphenylamine.
930552.................................... N-nitrosopyrrolidine (NPYR).
68224..................................... Norethindrone (19-
Norethisterone).
103651.................................... N-Propylbenzene.
95534..................................... O-Toluidine.
75569..................................... Oxirane, methyl-.
301122.................................... Oxydemeton-methyl.
42874033.................................. Oxyfluorfen.
14797730.................................. Perchlorate.
1763231................................... Perfluorooctane sulfonic
acid (PFOS).
335671.................................... Perfluorooctanoic acid
(PFOA).
52645531.................................. Permethrin.
41198087.................................. Profenofos.
91225..................................... Quinoline.
121824.................................... RDX.
135988.................................... Sec-Butylbenzene.
7440246................................... Strontium.
107534963................................. Tebuconazole.
112410238................................. Tebufenozide.
13494809.................................. Tellurium.
13071799.................................. Terbufos.
56070167.................................. Terbufos sulfone.
59669260.................................. Thiodicarb.
23564058.................................. Thiophanate-methyl.
26471625.................................. Toluene diisocyanate.
[[Page 51853]]
78488..................................... Tribufos.
121448.................................... Triethylamine.
76879..................................... Triphenyltin hydroxide
(TPTH).
51796..................................... Urethane.
7440622................................... Vanadium.
50471448.................................. Vinclozolin.
137304.................................... Ziram.
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Microbial Contaminants
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Adenovirus
Caliciviruses
Campylobacter jejuni
Enterovirus
Escherichia coli (0157)
Helicobacter pylori
Hepatitis A virus
Legionella pneumophila
Mycobacterium avium
Naegleria fowleri
Salmonella enterica
Shigella sonnei
------------------------------------------------------------------------
III. What Comments Did EPA Receive on the Draft CCL 3 and How Did the
Agency Respond?
EPA received comments from 177 individuals or organizations on the
draft CCL 3. Commenters identified several issues on the draft CCL 3
and the process used to select contaminants for the list. Many
commenters noted the substantial effort, overall improvement, improved
scientific rigor, and increased stakeholder involvement employed by EPA
to develop the draft CCL 3. Commenters also provided information and
recommendations for the Agency to consider as it finalized the CCL 3.
The Agency has provided responses to individual comments in the ``Final
Comment Response Document for the Third Drinking Water Contaminant
Candidate List 3 (Categorized Public Comments)'' document that is
available in the docket (USEPA 2009c).
A. Advisory From the EPA Science Advisory Board
The EPA SAB and its Drinking Water Committee reviewed the draft CCL
3 during 2008, and provided an advisory to the Administrator on January
29, 2009. EPA staff met with the SAB to provide an overview of the
draft CCL 3, to answer questions from the Drinking Water Committee, and
to clarify questions from the full SAB. The Agency also participated in
teleconferences with SAB during the development of the ``SAB Advisory
on EPA's Draft Third Drinking Water Contaminant Candidate List (CCL
3)'' (USEPA 2009d). SAB comments on the overall CCL 3 process and
documentation are summarized in the following paragraphs.
The SAB noted that the process used to develop the draft CCL 3
represents a major improvement over the previous CCL processes and
recognized the adaptive management strategies employed by EPA as an
appropriate approach that should continue to be used in future CCLs.
However, the SAB also believes the documentation of the process used to
develop the draft CCL 3 lacks transparency. For example, one suggestion
stated that EPA should document and justify why each of the
contaminants from previous CCL lists were excluded from the draft CCL
3.
The SAB also stated that the current list may be too large for
chemicals; and it may include too few pathogens. The SAB acknowledged
that the CCL 3 has dual goals of developing regulatory determinations
and identifying longer-term research needs. They also recommended that
EPA prioritize the list to better identify regulatory priorities,
research needs, and longer term needs for the next CCL.
EPA Response to SAB Recommendations
The Agency has updated the technical support documents for the CCL
3 to increase the transparency of the process that was used to
determine which contaminants to include on the final CCL 3. Several
specific suggestions to improve the transparency of the process are
addressed in the supporting documents and identified in Section III of
this notice. Documents describing the process and tables that identify
the data used to select contaminants can be found on EPA's Web site at:
http://www.epa.gov/safewater/ccl/index.html. More detailed information
on the contaminants, such as the ``Final CCL 3 Contaminant Information
Sheets.'', (USEPA, 2009e) and the ``Final Contaminant Candidate List 3
Microbes: PCCL to CCL Process'' can be found in the docket (USEPA,
2009g) and on EPA's Web site.
In Section IV of this FR notice, the Agency has also identified
which contaminants will need additional data and information on their
occurrence, health effects, and analytical methods. As the Agency
continues to evaluate contaminants on the CCL 3, we will work with EPA
and non-EPA scientists to develop and collect the best available
science to support decision making for future regulatory
determinations.
B. Chemical Contaminants
EPA evaluated data and information on chemical contaminants
provided by commenters and collected by the Agency after the draft CCL
3 was published. EPA used the same process described in the draft CCL 3
FR notice (73 FR 9628, USEPA 2008a) to evaluate contaminants for which
data became available after the publication of the draft CCL 3. Based
on these analyses, EPA is taking the following actions on chemical
contaminants: EPA is removing two pesticides from the CCL 3 that are no
longer used in the United States, and the Agency is adding 13 chemical
contaminants to the final CCL 3. EPA concluded that one antibiotic
(erythromycin), nine hormones (17 alpha-estradiol, 17 beta-estradiol,
equilenin, equilin, estriol, estrone, ethinyl estradiol, mestranol, and
norethindrone), two potential disinfection byproducts (DBP) (Halon 1011
(bromochloeromethane) and chlorate), and one perfluorinated compound
(Perfluorooctanoic sulfonic acid (PFOS)) should be included on the CCL
3 based on their potential adverse health effects and potential for
occurrence in public water systems. The Agency has summarized the
comments and information used to evaluate these contaminants in this
section of the FR notice. The specific data used to evaluate these
contaminants can be found in the response to comment document (USEPA,
2009c) and the ``Final CCL 3 Contaminant Information Sheets'' in the
docket (USEPA, 2009e).
1. Pesticides and Degradates
EPA received more than 65 public comments on pesticides and their
related degradates. Some commenters were concerned about the number of
pesticides listed on the draft CCL 3. One commenter states, ``* * * in
the process of narrowing the universe of 7,500 unregulated chemicals
down to 93 * * * EPA selected nearly half (42 out of 93) to be
pesticides or pesticide degradates.'' This and other commenters viewed
the listing of pesticides as a selection bias and noted that EPA has
not clearly demonstrated, in the process used to derive the draft CCL
3, that these 42 pesticides and degradates pose the greatest public
health concern. In addition, this commenter believed that the inclusion
and proportional share of pesticides and their degradates on the draft
CCL 3 should take into account the Agency's regulatory determination
findings where none of the pesticides or degradates evaluated were
ultimately determined to provide a meaningful opportunity to provide
public health protection. In contrast, some commenters were in
agreement with the pesticides included on the draft CCL 3, and in some
cases, commenters
[[Page 51854]]
suggested placing additional pesticides on the final CCL 3.
EPA Response: EPA does not agree with the commenter's statement
that there is a selection bias for pesticides. The CCL 3 process was
developed to evaluate contaminants from a broad universe of chemicals
in accordance with the NRC and NDWAC recommendations. The chemicals are
subject to consistent screening and evaluation based on chemical
specific factors such as physical properties, health effects data, and
their potential to occur in public water systems. SDWA requires EPA to
evaluate substances registered as pesticides under FIFRA. All
pesticides identified in the universe of chemicals were evaluated by
EPA using the same process as other chemicals. Previous regulatory
determinations not to develop a NPDWR for 10 pesticides or degradates
in Regulatory Determinations 1 and 2 are irrelevant to other pesticides
on the CCL 3. The regulatory determination process, like the CCL
process, is data driven. To make a regulatory determination, EPA
evaluates the available occurrence and health effects data for that
contaminant against the criteria in SDWA Section 1412 (b)(1)(a). The
Agency has responded to comments on specific pesticides in the response
to comment document (USEPA, 2009c).
2. Cancelled Pesticides Registrations
SAB and other public commenters suggested that specific pesticide
active ingredients (Nitrofen and Ethion) should be removed from the CCL
3 because they are no longer used in registered pesticides. The SAB
also commented that EPA should consider removing pesticides from the
CCL 3 that are no longer registered products or are in the process of
being phased out of use. The pesticides identified by the commenters,
Nitrofen and Ethion, are not included on the final CCL 3. The
evaluation of these two pesticides is summarized in the following
paragraphs.
a. Nitrofen
EPA received comment from the public and the SAB that Nitrofen
should not be included on the final CCL 3. Commenters noted that the
available information on use, release, and potential environmental
occurrence of Nitrofen indicate that it should not be anticipated to
occur in public water systems (PWS).
EPA Response: EPA agrees with the commenters that Nitrofen should
be removed from the CCL 3. It is no longer manufactured or sold in the
United States. Its inclusion on the draft list was based on a reported
TRI release which, when investigated, indicated that Nitrofen stocks
were recently found in a warehouse and properly disposed of in
accordance with the Resource Conservation and Recovery Act Subtitle C
landfill regulations. TRI requires that information on landfill
releases, even releases in compliance with regulations, be reported;
therefore, the Nitrofen release was incorporated in the total TRI data
used in the CCL process. Based on this information, Nitrofen is not
anticipated to occur in PWSs, and the Agency has not included Nitrofen
on the final CCL 3.
b. Ethion
Commenters noted that the registration for Ethion was cancelled and
therefore EPA should not include Ethion on the final CCL 3.
EPA Response: EPA agrees with the commenters and has not included
Ethion on the final CCL 3. On March 22, 2002, EPA published a
cancellation order discontinuing the manufacture of Ethion containing
products as of October 1, 2003, and prohibiting the use of existing
stocks after December 31, 2004 (67 FR 13328; USEPA, 2002). A July 23,
2004 action revoked the remaining Ethion tolerances, as of October 1,
2008 (69 FR 43918; USEPA, 2004). EPA notes that SDWA criteria consider
whether a contaminant is known or anticipated to occur in PWSs and may
have an adverse effect. It is possible for a contaminant to occur in a
PWS even after its uses are canceled if it is very persistent in the
environment. Ethion is moderately persistent in the environment, but is
not likely to contaminate surface water through dissolved runoff. Based
on laboratory and field data, including monitoring data compiled in
EPA's Pesticides in Ground Water Database, EPA does not expect that
Ethion will contaminate ground water (USEPA, 2001). Based on Ethion's
discontinued registration status, prohibited use of stocks, and
moderate persistence, the Agency does not anticipate that it will occur
in PWSs; therefore, it is not included on the final CCL 3.
3. Perfluorinated Compounds
In the draft CCL 3 FR notice, EPA sought comments on its proposed
decisions to include perfluorooctanoic acid (PFOA) and not to include
PFOS on the draft CCL 3 (73 FR 9652, USEPA 2008a). The majority of
commenters agreed with the inclusion of PFOA on the CCL 3. Commenters
pointed out that PFOA warrants inclusion on the CCL due to its known
occurrence in drinking water supplies and systems and its potential
adverse health effects. A number of these commenters also wrote in
support of regulating PFOA under SDWA. The SAB also stated that PFOA
should be a high priority for consideration by the Agency for the CCL
3. One commenter argued that EPA did not use the most relevant
information in the CCL 3 process to characterize PFOA's health effects
and occurrence. Some of the commenters who were in support of including
PFOA on the CCL also recommended adding PFOS and other perfluorinated
compounds to the list. The SAB noted that perfluorochemicals may be a
class of contaminants that the Agency should consider as a group based
on their similar structures and chemical makeup.
EPA Response: The Agency agrees with commenters that potential
health effects based on animal studies and the occurrence of PFOA in
drinking water supplies warrant its inclusion on the CCL 3. The Agency
used the best available science and information to evaluate and list
drinking water contaminant candidates. PFOA has been detected in a
number of drinking water supplies and ambient waters. It is also highly
persistent in the environment and has been shown to be toxic in animal
studies. Based on these potential adverse health effects and occurrence
information, EPA concludes that PFOA is known or anticipated to occur
in public water systems and may require regulation. Therefore EPA has
included PFOA on the final CCL 3.
PFOS was not included on the draft CCL 3, but has been included on
the final CCL 3. A major factor in EPA's decision to not include PFOS
on the draft CCL 3 was the voluntary phase-out of production of PFOS in
the U.S. between 2000 and 2002 (FR 73 9652; USEPA 2008a). However, EPA
has evaluated new information from the October 9, 2007, significant new
use rule (SNUR) that shows there are ongoing uses of PFOS that could
lead to its occurrence in water (FR 72 57222-57235; USEPA 2007b). The
Agency concluded, based upon this potential to occur in PWSs, existing
data on environmental persistence, and toxicity in animal studies, that
PFOS is known or anticipated to occur in public water systems and may
require regulation. Therefore, EPA has included this compound on the
final CCL 3.
The Agency continues to analyze the data and information related to
the possible adverse health effects associated with PFOA and PFOS. As
noted in the draft CCL 3 FR notice, the SAB completed a review of a
draft PFOA risk assessment in 2006 and made
[[Page 51855]]
recommendations for the further development of the risk assessment
(USEPA, 2006a). A number of important studies are underway, and the
Agency continues to participate in research regarding the toxicity of
related perfluorochemicals, as well as research to help identify routes
of human exposure. EPA is evaluating additional research and has not
made any definitive conclusions on the risk assessment at this time.
The Agency also issued ``Provisional Health Advisories for PFOA and
PFOS'' (USEPA 2009f) to provide technical information to State and
local officials, and PWSs for consideration in addressing local
contamination of drinking water to protect public health. This
information has been included in the docket and the ``Final CCL 3
Contaminant Information Sheets'' for PFOA and PFOS (USEPA, 2009e).
While the Agency did not specifically seek comment on other
perfluorinated compounds in the draft CCL 3 FR notice, some of these
compounds were included in the CCL 3 Universe. However, the Agency had
only limited data on the potential occurrence of these compounds and
potential adverse health effects. Commenters did not provide additional
occurrence or health effects data than those already evaluated by the
Agency; therefore, they are not listed on the CCL at this time. The
Agency will continue to evaluate perfluorinated compounds to ascertain
whether they possess similar toxicological properties and if they are
anticipated or known to occur in public water systems.
4. Pharmaceuticals
In the draft CCL 3 FR notice (73 FR 9652; USEPA, 2008a), EPA
explained how pharmaceuticals were evaluated in the CCL 3 process, and
sought additional data and information on the concentrations of
pharmaceuticals in finished or ambient water. EPA also requested
comment on how pharmaceuticals have been considered in the CCL 3
process. In addition, EPA sent a letter to State public health and
environmental departments requesting information on the States'
activities and initiatives involving pharmaceuticals. The Agency
specifically requested information on pharmaceuticals in the areas of
occurrence, human health effects research, analytical methods
development, and stewardship. EPA received a number of comments on
pharmaceuticals and the CCL 3. Commenters pointed out that additional
research is needed to address the health effects and occurrence of
pharmaceuticals in drinking water. Commenters also noted that the
contaminants were detected at low levels. Commenters differed on
whether pharmaceuticals should be included on the CCL 3. Some
commenters provided references from the published literature on the
occurrence of pharmaceuticals in water and on the health effects of
pharmaceuticals. In its comments, the SAB noted that pharmaceuticals
may be a class of contaminants that need special attention when
considering them for CCL 3 or future CCLs, and recommended that EPA use
additional data on occurrence of pharmaceuticals in water from the
United States Geological Survey (USGS), or studies in the peer-reviewed
literature (USEPA, 2009d).
EPA Response: EPA is actively working to evaluate the potential
risks to human health and aquatic life posed by trace amounts of
pharmaceuticals and personal care products in water, and to identify
measures to minimize their occurrence. The Agency has a number of
activities underway and will continue to add activities as appropriate.
All of these activities are described in further detail on our Web site
located at http://www.epa.gov/waterscience/ppcp. Additional information
on the Agency's research related to pharmaceuticals can be found at
http://www.epa.gov/ppcp.
In the CCL 3 process, EPA evaluated the potential adverse health
effects of pharmaceuticals and their occurrence in public drinking
water systems to determine if pharmaceuticals should be added to the
list. Since the draft CCL 3 was published, several publications have
focused on the occurrence of pharmaceuticals in ambient water and
drinking water. In response to comments, EPA has conducted additional
data collection efforts to comprehensively review recent published
information from USGS and other sources, including those cited by
commenters, to identify the best available occurrence information for
pharmaceuticals. EPA identified new occurrence data for 81 contaminants
from 22 sources. The Agency also conducted additional literature
reviews to identify the best available health effects information and
identified data from sources including: EPA Office of Pesticide
Programs, the Food and Drug Administration (FDA) Center for Veterinary
Medicine, the Joint Food and Agriculture Organization/World Health
Organization (WHO) Expert Committee on Food Additives, and the European
Medicines Agency, and the FDA Center for Drug Evaluation and Research.
EPA used the new data in the same process that was described in the
draft CCL 3 FR notice to further evaluate pharmaceutical contaminants.
Based upon this re-evaluation with new data, EPA concluded that one
antibiotic (erythromycin) and nine hormones (17 alpha-estradiol, 17
beta-estradiol, equilenin, equilin, estriol, estrone, ethinyl
estradiol, mestranol, and norethindrone), should be included on the CCL
3 because these contaminants are known or anticipated to occur in
public water systems and may require regulation. The specific data used
to evaluate these contaminants can be found in the ``Final CCL 3
Contaminant Information Sheets'' (USEPA, 2009e).
5. Perchlorate
EPA received several comments on perchlorate in response to the
draft CCL 3. Commenters noted that perchlorate should be included on
the final CCL 3 and provided occurrence and health effects data.
Commenters also identified potential sources of perchlorate in the
environment.
EPA Response: EPA included perchlorate on the first CCL in 1998 and
on the second CCL in 2005. EPA is including perchlorate on CCL 3 while
the Agency continues to evaluate scientific information related to a
regulatory determination.
EPA published a preliminary regulatory determination for
perchlorate in the FR on October 10, 2008 (73 FR 60262; USEPA, 2008b).
In this notice, EPA solicited public comment on its preliminary
determination not to regulate perchlorate. The Agency issued an interim
health advisory for perchlorate to provide technical information to
State and local officials and PWSs for consideration in addressing
local contamination of drinking water (USEPA, 2008c).
EPA received more than 32,000 comments on the preliminary
regulatory determination (73 FR 60262; USEPA 2008b). The majority of
comments were submitted by individuals opposed to the decision. There
were also unique comments that recommended further scientific
evaluation of the information EPA used to make the preliminary
determination. These commenters included EPA's NDWAC, SAB, and
Children's Health Protection Advisory Committee. All of the comments
received on the preliminary regulatory determination FR notice can be
reviewed on www.regulations.gov. Refer to docket number EPA-HQ-OW-2008-
0692.
6. Disinfection Byproducts (DBP)
EPA received several comments on unregulated disinfection
byproducts.
[[Page 51856]]
Most comments supported the inclusion of N-nitrosodimethylamine (NDMA)
and the other N-nitrosamines (N-nitrosodiethylamine, N-nitroso-di-n-
propylamine, N-nitrosodiphenylamine, N-nitrosopyrrolidine) on CCL 3,
citing the evidence for their carcinogenicity and the overarching need
to evaluate this risk. The SAB advised EPA to consider N-nitrosamines
as a group because of their similar toxicities and likelihood to occur
together. One commenter expressed concern that two N-nitrosamines: N-
nitroso-di-n-butylamine and N-nitroso-methylethylamine (which are
included in UCMR 2) are not listed on the draft CCL 3. Several
commenters expressed concern about the overall lack of DBPs on the
draft CCL 3, citing their assumed presence as a result of drinking
water disinfection. One commenter requested that the remaining halo-
acetic acids not covered under the current DBP regulation
(bromochloroacetic acid, dibromochloroacetic acid, bromodichloroacetic
acid, and tribromoacetic acid) be added to the CCL 3. Several
commenters mentioned groups of chemicals, such as halo-nitriles, halo-
aldehydes, halo-nitromethanes, and other nitrogenous DBPs that they
believed should be included on the CCL 3.
EPA Response: The CCL 3 process took into consideration the
potential formation of DBPs in disinfected and treated drinking water.
Potential DBPs with available health information were added to the CCL
Chemical Universe even if they did not have measured occurrence data.
This is because DBPs were considered to have ``default'' occurrence for
the Universe since they are potentially formed in treated drinking
water supplies (USEPA 2009a). In screening chemicals from the Universe
to the Preliminary CCL (PCCL), EPA added DBPs to the PCCL that lacked
quantitative occurrence data but were in the Toxicity Category 1 or
Toxicity Category 2 groupings because of their potential presence in
disinfected and treated drinking water (USEPA 2009b). EPA attempted to
identify additional health effects and occurrence data for these DBPs
to determine whether to include them on the CCL 3. Quantitative
occurrence data were needed in order for DBPs to be evaluated for
inclusion on the CCL 3. The Agency sought comment on the approach and
the data used to select contaminants in the draft CCL 3.
EPA evaluated 85 chemicals in the groups of potential DBPs
mentioned by the commenters, but the available data showed that most
DBPs had limited or low levels of occurrence, or lacked health effects
data. For example, the two UCMR 2 nitrosamines that are not on CCL 3
lacked sufficient occurrence information for inclusion on the list.
There is additional discussion of the interrelationship between the CCL
and UCMR in Section III.D of this FR notice.
Several commenters mentioned chemicals that were not included in
the Universe data compilation, but they did not submit the health
effects and/or occurrence information that would be necessary to
support their inclusion on the final CCL 3.
In addition to the data used by the Agency in the draft CCL 3, such
as the May 14, 1996, DBP Information Collection Rule (ICR) (61 FR
24354, USEPA 1996), EPA used drinking water occurrence data from the
State of California Department of Health Services ICR and studies cited
by commenters (Krasner et al., 2006) to evaluate the occurrence of
DBPs. The Agency also sought and identified new health effects
information. A study EPA requested during the development of the Stage
2 Rule on chlorate was completed (NTP 2008) and occurrence information
on bromochloromethane (Halon 1011) was also identified. EPA concluded
that chlorate and bromochloromethane are known or anticipated to occur
in PWSs and may require regulation. Therefore the Agency added these
two contaminants to the CCL 3.
EPA continues to participate in research concerning the toxicity,
occurrence, exposure, and treatment of unregulated disinfection
byproducts. This research will inform the development of future CCLs
and the regulatory determination process, as well as future reviews of
existing drinking water regulations.
C. Microbial Contaminants
EPA is including twelve pathogens on the final CCL 3, one more than
the eleven pathogens on the draft CCL 3. The Agency is adding
Adenovirus, Enterovirus, and Mycobacterium avium to the final CCL 3,
and is removing Vibrio cholerae and Entamoeba histolytica from the
final CCL 3.
The protocol EPA used to select the microbial contaminants for the
CCL 3 is described in detail in the draft CCL 3, notice (73 FR 9631,
9644; USEPA, 2008a). Except for a minor change discussed in Section
III.C.1, the protocol for selecting pathogens for the final CCL 3
remains the same as the protocol for the draft CCL 3; EPA selected the
pathogens based on their health effects and occurrence in drinking
water.
Based on public comment, EPA modified the waterborne disease
outbreak (WBDO) protocol. The Agency removed older, Centers for Disease
Control (CDC) reported WBDOs (prior to 1990) from the occurrence
analysis to account for the impact of drinking water regulations that
have been implemented since 1990. This change in the WBDO protocol
resulted in the exclusion of Vibrio cholerae and Entamoeba hystolitica
from the final CCL 3 and the inclusion of Adenovirus and Enterovirus to
the final CCL 3.
Based on public comment, EPA reviewed the health score for
Mycobacterium avium. After re-evaluating the health effects
information, EPA determined that a higher health effects score was
appropriate for this pathogen.
1. Using the CDC WBDO's as a Scoring Criterion
A commenter recommended the use of outbreak data tied to the
implementation of the SDWA and its amendments (i.e., after 1990). The
commenter, as well as SAB, also encouraged EPA to develop its own
occurrence database instead of relying on CDC reported WBDOs. A few
commenters noted that, in general, the information on occurrence of
pathogens in drinking water is limited, and that EPA should develop
more occurrence information.
EPA Response: EPA agrees in part with this recommendation, and
recognizes that after implementation of SDWA and its amendments, PWSs
should have changed their practices resulting in fewer outbreaks.
Therefore, early outbreaks (i.e., before 1990) may not represent the
current situation and controls at PWSs operating under these
regulations. EPA removed CDC WBDOs prior to 1990 from the occurrence
analysis. This change resulted in the exclusion of Vibrio cholerae and
Entamoeba hystolitica from the final CCL 3 because their WBDO scores
were reduced due to the removal of older documented WBDOs from
consideration (USEPA, 2009e).
EPA disagrees with abandoning the CDC database and continues to use
the CDC documented WBDOs in the CCL 3 pathogen scoring process. CDC
collects statistical data on WBDOs every year (since 1920). CDC has
consistently applied a definition for WBDO as well as consistently
investigated and verified epidemiological information related to
illnesses. This consistency in definitions and methods allows EPA to
consistently compare the WBDO data. In contrast, individual research
studies on isolated outbreaks may have different methods and goals, and
therefore disparate study designs, making evaluation of the results
difficult from a
[[Page 51857]]
national perspective. No other national database on drinking-water
related illnesses exists.
EPA contributes and collaborates with CDC on the Morbidity and
Mortality Weekly Report's annual surveillance summary, and is confident
of the quality of the information in the report. EPA agrees with the
commenter that there is a need for more information on occurrence of
pathogens in drinking water; however, EPA believes that the CDC WBDO
data is the best available information at this time.
2. Mycobacterium Avium
EPA received more than a dozen comments requesting that EPA re-
examine the health effects score for Mycobacterium avium and to include
the pathogen on the final CCL 3. Commenters pointed to the long
treatment duration and the severity of the disease particularly for the
elderly population. Commenters also cited the increased incidence of
disease, particularly amongst the elderly.
EPA Response: EPA re-evaluated Mycobacterium avium's health effects
information and increased the health effects score for one of the
sensitive life stages, or populations; specifically, the elderly. The
Agency agrees with commenters that the potential health effects on the
elderly and the occurrence of Mycobacterium avium in drinking water
supplies warrant its inclusion on the CCL 3. The health effects score
was increased based on the severity and treatment duration on the
elderly as described in Murray 2007 (USEPA, 2009g). Based on this
information, EPA anticipates that Mycobacterium avium may occur in PWSs
and require regulation. Therefore the Agency has included Mycobacterium
avium on the final CCL 3.
3. Vibrio cholerae and Entamoeba hystolitica
EPA received a few comments recommending the exclusion of both
Vibrio cholerae and Entamoeba hystolitica from the final CCL 3.
Commenters recommended that EPA not include these pathogens because
cholera and amebiasis are currently rare in the United States, even
though they are still common in other countries. Also, commenters felt
that current treatment practices (i.e., disinfection) will provide
sufficient protection against Vibrio cholerae. However, one commenter
supported keeping Vibrio cholerae because its occurrence is likely to
increase and expand as climate change continues.
EPA Response: Based on public comment discussed earlier, EPA
changed the WBDO protocol. The Agency removed older, CDC reported WBDOs
(prior to 1990) from the occurrence analysis to account for recently
implemented regulations (e.g., Surface Water Treatment Rule, Total
Coliform Rule). This change in the WBDO protocol resulted in the
reduction of the WBDO score for both Vibrio cholerae and Entamoeba
hystolitica, and their exclusion from the final CCL 3. However, EPA did
not consider treatment as one of the parameters for inclusion or
exclusion of a pathogen onto the CCL 3 because many public water
systems are not required to treat, as discussed in the draft CCL 3 FR
notice (73 FR 9648; USEPA, 2008a). Further, EPA acknowledges the
potential impact climate change may have on water quality; however, at
this time EPA does not have enough information to assess the risk.
D. Other Comments
1. Data Sources for Contaminant Candidate Lists
Several commenters noted that EPA used occurrence data sources that
could only identify a contaminant's potential to occur in PWSs. These
included data from the TRI, National Center for Food and Agricultural
Policy (NCFAP), modeled occurrence data for pesticides, and chemical
production data. While some commenters urged EPA to rely on this type
of data, other commenters suggested that production data should only be
used to identify chemicals for initial consideration (i.e., inclusion
on the CCL 3 Universe) and more rigorous data should be used to screen
or include chemicals on the CCL.
EPA response: The Agency used data from the TRI and modeled
occurrence data for pesticides developed by the Office of Pesticide
Programs (OPP) to support the inclusion of contaminants on the CCL 3,
but EPA did not rely on the Chemical Update System (CUS) and the
Inventory Update Rule (IUR) data (i.e., production volume).
In developing the CCL, SDWA requires that EPA consider unregulated
contaminants that are known or anticipated to occur in PWSs and may
require regulation. EPA believes that the TRI and the OPP data are
sufficient for it to anticipate that a contaminant that is released
into the environment may occur in a PWS. The Agency coupled these data
with health effects information to evaluate contaminants. The NRC
(2001) and NDWAC (2004) reports included specific recommendations on
data and information that the Agency could use to anticipate the
occurrence of contaminants in PWSs. Both of these panels cited the
importance of identifying contaminants that did not yet have occurrence
information indicating detections in source waters or drinking water.
NDWAC recognized that the Agency could apply a hierarchy to the use of
detected occurrence over potential occurrence, but also noted that the
use of these types of data enables the Agency to be proactive in
protecting public health.
EPA also conducted several reviews of the data sources and
information used to develop the CCL 3. EPA sought contaminants for the
Agency to consider in its FR notice, seeking nominations (71 FR 65573,
USEPA 2006b). The Agency published a list of data sources including the
TRI, CUSIUR, and NCFAP. Many of the nominated contaminants are
chemicals included solely on those lists. The Agency also conducted
several expert panels to review the types of data and information it
used to evaluate contaminants. While these panels provided
recommendation to qualify these types of data, which the Agency
implemented, the panels did not recommend excluding these data sources.
Based on this input from stakeholders and expert reviews, the Agency
included 51 contaminants with TRI and/or modeled occurrence data for
pesticides to support inclusion on the CCL 3 because EPA anticipates
that these contaminants may occur in PWSs and may require regulation.
2. Contaminant Candidate List and Unregulated Contaminant Monitoring
Regulation
Several commenters requested clarification on the interrelationship
between the UCMR and the CCL. Commenters wanted to know whether the CCL
draws from chemicals on the UCMR, or the UCMR draws from chemicals on
the CCL to develop the respective lists. One commenter encouraged EPA
to ``improve correlation between the CCL and the UCMR.''
EPA response: The 1996 amendments to SDWA instituted the CCL and
UCMR programs to provide information EPA needs to determine which
drinking water contaminants have the greatest potential to present a
meaningful opportunity to reduce health risk through a NPWDR. The CCL
is the primary mechanism for the identification of contaminants that
may require regulation, while UCMR provides EPA with the data necessary
to determine if a contaminant occurs at a frequency and at levels of
public health concern. The CCL and UCMR are parts
[[Page 51858]]
of the risk management process, and they support and inform each other.
The UCMR sampling program was designed to consider the technical
difficulty and expense of analyzing up to 30 contaminants as well as
their potential to occur in treated drinking water at levels of public
health concern. The UCMR approach includes three different sampling
design options, with the determination of the appropriate option for
each contaminant based primarily on the difficulty and expense of the
analytical methods used, and the associated issue of laboratory
capacity. The sampling designs described below are discussed in detail
in the proposed UCMR 2 (70 FR 49094; USEPA 2005). Assessment monitoring
is the most extensive, and is used when the technology of the
analytical methods is in common use in drinking water laboratories.
Screening monitoring relies more on identifying a statistically valid
representation of the universe of PWSs in order to reduce the number of
utilities impacted by the monitoring. It is designed to assure the
necessary laboratory capacity in those cases where the analytical
technology is more complex and/or expensive. The pre-screening
monitoring option detailed in the UCMR program is based on assessing
the vulnerability of selected PWSs and may be used when the analytical
techniques are so complex that commercial laboratory capacity is
severely limited; this option has not been exercised to date.
EPA promulgated UCMR 2 on January 4, 2007 (72 FR 367; USEPA 2007a).
The UCMR program was developed in coordination with the development of
the CCL. Both programs consider the adverse health effects a
contaminant may pose through drinking water exposures.
Sixteen contaminants on the UCMR 2 monitoring list are also on the
final CCL 3. The final CCL 3 includes acetochlor and its degradates,
alachlor degradates, dimethoate, 1,3-dinitrobenzene, metolachlor and
its degradates, RDX, terbufos sulfone, and four of the nitrosamines
that are a part of UCMR 2. In addition to the health effects data and
potential occurrence, the UCMR 2 also considers analytical method
availability and cost, availability of analytical standards, and
laboratory capacity to support a nationwide monitoring program in
selecting contaminants.
The UCMR 2 includes nine contaminants that are not on the final CCL
3. The five polybrominated flame retardants can be measured by the same
analytical method used for terbufos sulfone. The polybrominated flame
retardants are listed on UCMR 2 because of concern that these have
become more widespread environmental contaminants (Darnerud et al.,
2001). The polybrominated flame retardants lacked sufficient occurrence
information to be listed on final CCL 3 (73 FR 9628; USEPA 2008a). This
UCMR 2 monitoring data will provide information for future CCLs.
Similarly, 2,4,6-trinitrotoluene (TNT) and two of the nitrosamines not
on CCL 3 are also measured by an analytical method in the UCMR 2.
Alachor was listed on UCMR 2 for monitoring along with its degradates
to allow for the measurement of co-concurrence between the parent
compound and its degradates. It was removed from consideration for CCL
3 because it is currently regulated. The Agency will use the results
from UCMR 2 as a source of occurrence information during the
development of CCL 4, as well as for CCL 3 regulatory determinations.
IV. Data Needs for CCL 3 Contaminants
After the listing process, the CCL 3 contaminants are evaluated
further to determine if a contaminant has sufficient data to meet the
regulatory determination criteria set forth in SDWA section 1412(b)(1)
and previously outlined in Section I.C of this notice. If the data are
sufficient, a regulatory determination may be made. EPA must make
regulatory determinations on at least five CCL 3 contaminants every
five years.
The SAB and other commenters have indicated that the CCL 3 may be
too large and recommended additional priority ranking of contaminants
to focus resources. EPA acknowledges that many contaminants on the CCL
3 have substantial data and information needs that will have to be met
before the Agency can make a regulatory determination in accordance
with SDWA 1412 (b)(1)(A). Currently, several of the CCL 3 contaminants
have data or information needs. These are described in the following
section.
A. Chemical Contaminants
EPA assessed the data and information gathered on the CCL 3
chemical contaminants and generated a table (Exhibit 2) to help
identify data/information needs for further regulatory determination
evaluations. In general, EPA characterized each chemical contaminant
included on the final CCL 3 for their data needs in three categories;
health effects, occurrence, and analytical methods. The data needs were
characterized as no data needs, specific data needs, or substantial
data needs. The health effects, occurrence, and analytical methods
data/information used to classify data needs are featured in the
supporting documentation and in the ``Final CCL 3 Contaminant
Information Sheets'' in the docket (USEPA, 2009e). Blank cells in
Exhibit 2 generally indicate that there is no data need for that
contaminant in that category. Cells with a ``2'' indicate that the data
are under evaluation by EPA and the contaminant has a specific need.
Cells with a ``1'' indicate that there is a data need for that
contaminant, and that need may be substantial. The following sections
describe the types of data or information gaps outlined in Exhibit 2
and provide examples.
1. Health Effects
EPA categorized the health effects data needs for Exhibit 2 using
the following set of assumptions. Any chemical that had an existing EPA
quantitative assessment (Reference Dose (RfD) or Cancer Slope Factor
(CSF)) for the oral route of exposure is identified on the table as not
having a health effect data need based on the assumption that EPA will
be able to use the existing data along with more recent studies to
develop a quantitative health effects assessment. These chemicals are
designated with a blank cell in the health effects column. There may
well be opportunities to further elucidate mode of action or to reduce
uncertainty for the analyses associated with these contaminants, but
such data would not be necessary to develop an assessment. Similarly,
any chemical that has an assessment being developed by EPA is not
identified on the table as having a data need, and is represented by a
blank cell because that work is currently ongoing.
The next category of chemicals with health effects data needs have
quantitative assessments conducted by other government agencies such as
WHO, and Agency for Toxic Substances and Disease Registry. These
chemicals are designated with a ``2'' in the health effects column on
the table, signifying that an EPA assessment is needed and sufficient
information may be available to initiate the assessment. These data
apply to oral exposures that can be used to support a quantitative
assessment of risk; however, EPA has not yet thoroughly evaluated the
existing risk assessment to determine if it and the supporting data
meet EPA data quality guidelines and is compatible with EPA risk
assessment policies. For example, at times there may be an RfD-
equivalent for oral exposures based on inhalation data (i.e.,
California EPA), which is an approach EPA does not typically use unless
there is a physiologically-based
[[Page 51859]]
pharmacokinetic model that supports the cross route extrapolation. The
Agency is currently evaluating whether this type of model information
and results are available. For a few chemicals marked with the ``2''
designation in the health effects column, there is no assessment by
another agency, but EPA identified a critical study suitable for
quantification of likely cancer risk during the development of the CCL
3 process. In these cases, an assessment is needed based on the data
identified.
The final group of chemicals on Exhibit 2 is designated with a
``1'' in the health effects column of the table. For these chemicals,
the CCL process used data from a small group of studies identified
through the Registry of Toxic Effects for Chemical Substances (RTECS),
a provisional Risk Assessment Information System Health Effects
assessment, and/or a limited literature search for the health effects
component of the CCL 3 evaluation. These chemicals have the most
substantial health effects data gaps and information collection needs.
2. Occurrence
EPA categorized the occurrence data needs for Exhibit 2, after
evaluating data availability from UCMR 1 and 2, Unregulated Contaminant
Monitoring Round 1 and 2 (UCM R1/2), National Inorganic Radiological
Survey (NIRS), NAWQA, TRI, NCFAP, and other supplemental data sources.
Chemicals with finished water occurrence data from UCMR 1, UCMR 2,
or UCM R1/2 were generally characterized as not having an occurrence
data gap because these data are considered nationally representative;
therefore, they have sufficient occurrence data to be further evaluated
if it is consistent with the health effects information. These
chemicals are designated with a blank cell in the occurrence column of
Exhibit 2.
Contaminants from data sources with limited PWS monitoring data
(i.e., ground water systems only), spatial or geographical data
limitations, and/or a small sample size were identified as having a
data gap because additional monitoring data may be needed for further
evaluation as part of the regulatory determinations process. These were
given a ``2'' in the occurrence column of Exhibit 2, and examples of
data sources with this type of data include the UCMR screening survey,
NIRS, DBP ICR data, and others.
Chemicals from occurrence data sources with ambient monitoring
data, environmental release data, or modeled data were given a ``1'' in
the occurrence column because there are substantial additional data
needs to be considered and evaluated as part of the regulatory
determinations process. Examples of data sources with this type of data
include USGS's NAWQA, National Reconnaissance of Emerging Contaminants,
TRI, and others with similar data.
3. Analytical Methods
To conduct nationally representative drinking water occurrence
studies, and support a regulatory determination, EPA must have an
analytical method that is suitable for the drinking water matrix and is
robust enough to be used by many laboratories to conduct national
studies and/or compliance monitoring. The analytical method should be
sensitive enough to allow for quantitation of the chemical at a
concentration below the HRL, or as close to the HRL as practically
feasible.
EPA categorized available analytical methods for the CCL chemicals
to define the data needs presented in Exhibit 2. EPA reviewed the
methods to assess if they had been developed for drinking water and
then evaluated estimated reporting levels for the chemical by that
method. When available, method-specific reporting levels, lowest
concentration minimum reporting levels, and promulgated minimum
reporting levels were also used to measure method sensitivity. When
this was not possible, EPA used a value of five times the method
detection limit or detection limit; this approach has been used in the
past.
Chemicals with blanks in the analytical methods column of Exhibit 2
are generally those chemicals for which EPA has an established drinking
water method, with estimated reporting levels that are adequate for
analysis relative to the HRL. However, in some cases, a blank may also
signify that EPA is currently in the process of developing a method
that it believes will have adequate reporting levels. Chemicals with a
``2'' in the analytical method column of Exhibit 2 have a drinking
water method that is under development by EPA. EPA has evaluated the
available methods for each of these chemicals and determined that the
reporting level does not allow for quantitation of the chemical at a
concentration below the HRL or as close to the HRL as practical.
Therefore, EPA has designated that these methods require further
development to increase their sensitivity and lower the estimated
method reporting level or method detection level. Those chemicals
listed as a ``1'' in the methods column do not have an established
method for drinking water or a method that is suitable for a national
drinking water occurrence study.
Key to Exhibit 2
The following key is a reference guide to reading Exhibit 2 and
interpreting the data presented in the table.
Note: Categories are based on the extent of available data for
each contaminant.
1. Health Effects:
1 = Substantial data needs (RTECS, RAISHE, and other small study
data); 2 = Assessments exist from other government agencies.
Sufficient information may exist to conduct an EPA assessment; Blank
= Existing or ongoing EPA quantitative assessment (e.g., IRIS)
2. Occurrence:
1 = No comprehensive drinking water occurrence data (e.g., often
only environmental release data such as TRI, or ambient water data),
2 = Limited available drinking water monitoring data; however, data
may be limited by scope and sample size (e.g., UCMR 1 Screening
Survey, NIRS); Blank = EPA has more extensive national drinking
water monitoring data (e.g., UCMR, UCM R1/2)
3. Analytical Method:
1 = No analytical method suitable for national drinking water
occurrence studies; 2 = Drinking water method in development or
being re-evaluated for comparison with new health effects
information; Blank = EPA has a method or is in the process of
developing a method that could be used for national drinking water
monitoring.
Exhibit 2. Regulatory Determination Data/Information Needs for CCL 3 Chemicals
----------------------------------------------------------------------------------------------------------------
Health Analytical
CASRN Common name effects Occurrence methods
----------------------------------------------------------------------------------------------------------------
630206............................. 1,1,1,2-Tetrachloroethane....... ......... .............. ..............
75343.............................. 1,1-Dichloroethane.............. 1 .............. 2
96184.............................. 1,2,3-Trichloropropane.......... ......... .............. ..............
106990............................. 1,3-Butadiene................... 1 1 2
99650.............................. 1,3-Dinitrobenzene.............. ......... .............. ..............
[[Page 51860]]
123911............................. 1,4-Dioxane..................... ......... 1 ..............
71363.............................. 1-Butanol....................... ......... 1 1
109864............................. 2-Methoxyethanol................ 2 1 1
107186............................. 2-Propen-1-ol................... ......... 1 1
16655826........................... 3-Hydroxycarbofuran............. 2 .............. ..............
101779............................. 4,4'-Methylenedianiline......... 2 1 1
30560191........................... Acephate........................ ......... 1 2
75070.............................. Acetaldehyde.................... ......... 2 ..............
60355.............................. Acetamide....................... 2 1 1
34256821........................... Acetochlor...................... ......... .............. ..............
187022113.......................... Acetochlor ethanesulfonic acid 2 .............. ..............
(ESA).
184992444.......................... Acetochlor oxanilic acid (OA)... 2 .............. ..............
107028............................. Acrolein........................ ......... 1 1
142363539.......................... Alachlor ethanesulfonic acid 2 .............. ..............
(ESA).
171262172.......................... Alachlor oxanilic acid (OA)..... 2 .............. ..............
319846............................. alpha-Hexachlorocyclohexane..... ......... 1 2
64285069........................... Anatoxin-a...................... ......... 1 2
62533.............................. Aniline......................... 2 1 1
741582............................. Bensulide....................... ......... 1 1
100447............................. Benzyl chloride................. ......... 1 1
25013165........................... Butylated hydroxyanisole........ 2 1 2
133062............................. Captan.......................... ......... 1 2
14866683........................... Chlorate........................ ......... 2 ..............
74873.............................. Chloromethane (Methyl chloride). 2 .............. ..............
110429624.......................... Clethodim....................... ......... 1 2
7440484............................ Cobalt.......................... ......... 2 ..............
80159.............................. Cumene hydroperoxide............ 1 1 1
143545908.......................... Cylindrospermopsin.............. ......... 1 2
141662............................. Dicrotophos..................... ......... 1 2
55290647........................... Dimethipin...................... ......... 1 2
60515.............................. Dimethoate...................... ......... .............. ..............
298044............................. Disulfoton...................... ......... 2 ..............
330541............................. Diuron.......................... ......... 2 ..............
114078............................. Erythromycin.................... 2 1 1
13194484........................... Ethoprop........................ ......... 1 2
107211............................. Ethylene glycol................. ......... 1 1
75218.............................. Ethylene oxide.................. 1 1 1
96457.............................. Ethylene thiourea............... ......... 1 2
22224926........................... Fenamiphos...................... ......... 1 2
50000.............................. Formaldehyde.................... ......... 2 ..............
7440564............................ Germanium....................... 1 2 2
74975.............................. Halon 1011 (bromochloromethane). 1 .............. 2
75456.............................. HCFC-22......................... 1 1 2
110543............................. Hexane.......................... 1 1 1
302012............................. Hydrazine....................... ......... 1 1
10265926........................... Methamidophos................... ......... 1 2
67561.............................. Methanol........................ ......... 1 1
74839.............................. Methyl bromide (Bromomethane)... ......... .............. ..............
1634044............................ Methyl tert-butyl ether......... ......... .............. ..............
51218452........................... Metolachlor..................... ......... .............. ..............
171118095.......................... Metolachlor ethanesulfonic acid 2 .............. ..............
(ESA).
152019733.......................... Metolachlor oxanilic acid (OA).. 2 .............. ..............
101043372.......................... Microcystin-LR.................. ......... 1 2
2212671............................ Molinate........................ ......... .............. ..............
7439987............................ Molybdenum...................... ......... 2 ..............
98953.............................. Nitrobenzene.................... ......... .............. ..............
55630.............................. Nitroglycerin................... 2 1 1
872504............................. N-Methyl-2-pyrrolidone.......... 2 1 1
55185.............................. N-Nitrosodiethylamine (NDEA).... ......... .............. ..............
62759.............................. N-nitrosodimethylamine (NDMA)... ......... .............. ..............
621647............................. N-Nitroso-di-n-propylamine ......... .............. ..............
(NDPA).
86306.............................. N-Nitrosodiphenylamine.......... ......... 1 1
930552............................. N-nitrosopyrrolidine (NPYR)..... ......... .............. ..............
103651............................. n-Propylbenzene................. 1 .............. 2
95534.............................. o-Toluidine..................... 2 1 2
75569.............................. Oxirane, methyl-................ ......... 1 1
301122............................. Oxydemeton-methyl............... ......... 1 2
42874033........................... Oxyfluorfen..................... ......... 1 2
14797730........................... Perchlorate..................... ......... .............. ..............
1763231............................ Perfluorooctane sulfonic acid 2 1 ..............
(PFOS).
335671............................. Perfluorooctanoic acid (PFOA)... 2 1 ..............
[[Page 51861]]
52645531........................... Permethrin...................... ......... 1 2
41198087........................... Profenofos...................... ......... 1 2
91225.............................. Quinoline....................... ......... 1 2
121824............................. RDX............................. ......... .............. ..............
135988............................. sec-Butylbenzene................ 1 .............. 2
7440246............................ Strontium....................... ......... 2 ..............
107534963.......................... Tebuconazole.................... ......... 1 2
112410238.......................... Tebufenozide.................... ......... 1 1
13494809........................... Tellurium....................... 1 2 2
13071799........................... Terbufos........................ ......... 2 ..............
56070167........................... Terbufos sulfone................ 2 .............. ..............
59669260........................... Thiodicarb...................... ......... 1 2
23564058........................... Thiophanate-methyl.............. ......... 1 2
26471625........................... Toluene diisocyanate............ 2 1 1
78488.............................. Tribufos........................ ......... 1 2
121448............................. Triethylamine................... 1 1 1
76879.............................. Triphenyltin hydroxide (TPTH)... ......... 1 1
51796.............................. Urethane........................ 2 1 1
7440622............................ Vanadium........................ 2 2 ..............
50471448........................... Vinclozolin..................... ......... 1 2
137304............................. Ziram........................... ......... 1 1
57910.............................. 17alpha-estradiol............... 1 1 1
517099............................. Equilenin....................... 1 1 1
474862............................. Equilin......................... 1 1 1
50282.............................. Estradiol (17-beta estradiol)... 2 1 ..............
50271.............................. Estriol......................... 1 1 2
53167.............................. Estrone......................... 1 1 2
57636.............................. Ethinyl Estradiol (17-alpha 1 1 2
ethynyl estradiol).
72333.............................. Mestranol....................... 1 1 1
68224.............................. Norethindrone (19- 1 1 1
Norethisterone).
----------------------------------------------------------------------------------------------------------------
B. Microbial Contaminants
EPA intends to look at the over-arching risk posed by pathogens
in drinking water. To this end, EPA is planning to evaluate the CCL
3 pathogens in the context of the existing drinking water regulatory
program to determine the sufficiency of the barriers that help to
prevent exposure.
Commenters noted a need for information on the national
occurrence of pathogens in drinking water. Development of such data
would aid EPA in determining the likelihood that pathogens will
occur in public water systems and thus clarify the extent to which
they represent a significant public health threat. One aspect of
determining the occurrence of any contaminant is the availability of
a method to monitor for that contaminant. While there are many
methods for monitoring the CCL 3 pathogens available from scientific
papers and consensus organizations, not all of them may be
appropriate for use in drinking water or for a national monitoring
effort. Of the CCL 3 pathogens, only enterovirus has an EPA-approved
method for drinking water. EPA is working on developing and
approving drinking water methods for some of the pathogens, and is
considering the need for additional occurrence information. In
addition, EPA is evaluating the suitability of current microbial
indicators as well as the reliability of other indicators for CCL
pathogens.
Furthermore, the Agency is actively working with stakeholders on
additional information on distribution system issues needed to
inform national risk management actions such as regulations and
guidance. Based on currently available information, EPA and other
stakeholders have identified the following issues as being the most
relevant to protecting public health and maintaining the integrity
of drinking water distribution systems for future consideration:
cross connections and backflow of contaminated water; storage
facility design, operation, or maintenance; main installation,
repair or rehabilitation practices; intrusion due to pressure
conditions; significance and control of biofilm and microbial
growth; nitrification issues; and accumulation and release of
contaminants from distribution system scales and sediments. These
issues may be applicable to chemicals as well as microbial
contaminants.
V. Next Steps/Future Candidate Contaminant Lists
The CCL process is a critical input to shaping the future
direction of the drinking water program. The Agency will continue to
gather information and evaluate contaminants on the CCL 3 to make a
regulatory determination for at least five contaminants by 2013. The
Agency will also continue to refine the CCL process and gather more
data to identify contaminants for the fourth CCL by 2014. EPA will
also continue to work to prioritize contaminants on the CCL 3, both
for regulatory determination and for additional research and data
collection.
VI. References
Darnerud, P.O., G.S. Erickson, T. Johannesson, P.B. Larson, and
M. Viluksela. 2001. Polybrominated Diphenyl Ethers: Occurrence,
Dietary Exposure, and Toxicology. Environmental Health Perspectives
Supplements. Vol. 109, No. S1. Available on the Internet at: http://ehp.niehs.nih.gov/members/2001/suppl-1/49-68darnerud/darnerud-full.html.
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.
National Toxicology Program (NTP). 2008. Toxicology and
carcinogenesis studies of sodium chlorate (CAS No. 7775-09-9) in
F344/N rats and B6C3F1 mice (drinking water studies). TR-
517. U.S. Department of Health and Human Services. http://ntp.niehs.nih.gov/?objectid=00132319-F1F6-975E-778A4E6504EB9191.
Krasner, S. W., H. S. Weinberg, et al. (2006). ``Occurrence of a
new generation of disinfection byproducts.'' Environ. Sci. Technol
40(23): 7175-7185.
USEPA. 1996. National Primary Drinking Water Regulations:
Monitoring Requirements for Public Drinking Water Supplies:
Cryptosporitium, Giardia, Viruses, Disinfection Byproducts, Water
Treatment Plant Data and Other Information Requirements; Final Rule.
Federal Register. Vol. 61, No. 94. p. 24354. May 14, 1996.
USEPA. 2001. Reregistration Eligibility Decision for Ethion.
Available at: http://
[[Page 51862]]
www.epa.gov/pesticides/reregistration/REDs/ethion_letter.htm
(Section III. Summary of Ethion Risk Assessment, B. Environmental
Risk Assessment 1. Environmental Fate and Transport) or in hard copy
form from the EPA's Office of Pesticide Program's Special Docket
(Docket ID: EPA-HQ-OPP-2007-0151-0007 on http://www.regulations.gov).
USEPA. 2002. Ethion; Cancellation Order. Federal Register. Vol
67, No. 56. p. 13328, March 22, 2002.
USEPA. 2004. Bitertanol, Chlorpropham, Cloprop, Combustion
Product Gas, Cyanazine, et al.; Tolerance Actions. Federal Register.
Vol. 69, No. 141. p. 43918, July 23, 2004.
USEPA. 2005. Unregulated Contaminant Monitoring Regulation
(UCMR) for Public Water Systems Revisions; Proposed Rule. Federal
Register. Vol. 70, No. 161. p. 49094. August 22, 2005.
USEPA. 2006a. SAB Review of EPA's Draft Risk Assessment of
Potential Human Health Effects Associated with PFOA and Its Salts.
EPA-SAB-06-006.
USEPA. 2006b. National Primary Drinking Water Regulations:
Ground Water Rule; Final Rule. Federal Register. Vol. 71, No. 216.
p. 65573, November 8, 2006.
USEPA. 2007a. Unregulated Contaminant Monitoring Regulation
(UCMR) for Public Water Systems Revisions; Final Rule. Federal
Register. Vol. 72, No. 2. p. 367, January 4, 2007.
USEPA. 2007b. Perfluoroalkyl Sulfonates; Significant New Use
Rule. Federal Register. Vol. 72, No. 194, p. 57222-57235, October 9,
2007.
USEPA. 2008a. Drinking Water Contaminant Candidate List 3--Draft
Notice. Federal Register. Vol, 73. No 35. p. 9628. February 21,
2008.
USEPA. 2008b. Drinking Water: Preliminary Regulatory
Determination on Perchlorate. Federal Register. Vol. 73. No 198. p.
60262. October 10, 2008.
USEPA. 2008c. Interim Drinking Water Health Advisory for
Perchlorate. EPA 822-R-08-025. December 2008.
USEPA. 2009a. Final Contaminant Candidate List 3 Chemicals:
Identifying the Universe. EPA. 815-R-09-006. August, 2009.
USEPA. 2009b. Final Contaminant Candidate List 3 Chemicals:
Screening to a PCCL. EPA 815-R-09-007. August, 2009.
USEPA. 2009c. Final Comment Response Document for the Third
Drinking Water Contaminant Candidate List 3 (Categorized Public
Comments). EPA 815-R-09-010. August, 2009.
USEPA. 2009d. SAB Advisory on EPA's Draft Third Drinking Water
Contaminant List (CCL 3). EPA-SAB-09-011. January 2009. http://yosemite.epa.gov/sab/sabproduct.nsf/WebProjectsbyNameBOARD!OpenView.
USEPA. 2009e. Final CCL 3 Contaminant Information Sheets. EPA
815-R-09-012. August, 2009.
USEPA. 2009f. Provisional Health Advisories for
Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS).
January 2009.
USEPA. 2009g. Final Contaminant Candidate List 3 Microbes: PCCL
to CCL Process. EPA 815-R-09-009. August, 2009.
Dated: September 21, 2009.
Michael H. Shapiro,
Acting Assistant Administrator, Office of Water.
[FR Doc. E9-24287 Filed 10-7-09; 8:45 am]
BILLING CODE 6560-50-P