vvEPA
United States
Environmental Protection
Agency
Response to Comments Document on the
Draft Fifth Contaminant Candidate List
(CCL 5)
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Office of Water (4607M)
EPA 815-R-22-001
October 2022
www, epa. gov/ safewater
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EPA-OGWDW
Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Table of Contents
Abbreviations and Acronyms 5
1. Introduction and Overview 8
Background 8
Who Submitted Comments 8
Science Advisory Board 9
Comment Organization 9
EPA's Categorization of Public Comments and Document Organization 10
Cross Referencing of Responses 10
2. Comments and EPA Responses by Topic 14
General Comments 14
Length of CCL 5 23
Other Drinking Water Programs 25
Other EPA Programs 33
Comments Related to Process - Chemicals 36
Chemical Data/Data Sources 37
Contaminant Groups 47
Cyanotoxins 51
Disinfection Byproducts (DBPs) 54
Per- and Polyfluoroalkyl substances (PFAS) 58
Pesticides 116
Individual Chemical Contaminants 117
1,4-Dioxane 118
Chlorpyrifos 119
Cobalt 120
Manganese 123
Tungsten 129
Vanadium 130
Molybdenum 135
Chemical Technical Support Documents 136
Microbial Screening Process/Criteria 142
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Draft CCL 5-Microbes 143
Legionella pneumophila 145
Mycobacterium 147
Contaminants Not on the Draft CCL 5 (Hepatitis A and Salmonella enterica) 149
Perchlorate 149
Endocrine Disruptor Chemicals (EDCs) and Pharmaceuticals and Personal Care Products (PPCPs).... 151
Suggestions to Improve the Process for Future CCLs 152
Comments Outside the Scope of CCL 155
References 157
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Abbreviations and Acronyms
ATSDR
Agency for Toxic Substances and Disease Registry
AMWA
Association of Metropolitan Water Agencies
ASDWA
Association of State Drinking Water Administrators
A WW A
American Water Works Association
CASRN
Chemical Abstracts Service Registry Number
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
CCL 5
EPA's Fifth Contaminant Candidate List
CDC
Centers for Disease Control
CDR
Chemical Data Reporting
CI
Cobalt Institute
CISs
Contaminant Information Sheets
CFR
Code of Federal Regulations
cPAD
Chronic Population-Adjusted Dose
CWA
Clean Water Act
CWS
Community Water System
DBP
Disinfection Byproduct
D/DBPR
Disinfectants and Disinfection Byproducts Rule
DRI
Dietary Reference Intake
DTXSID
Distributed Structure-Searchable Toxicity Database Substance Identifier
EDCs
Endocrine Disruptors
EDSP
Endocrine Screening Program
EPA
United States Environmental Protection Agency
FR
Federal Register
FDA
Food and Drug Administration
FIFRA
Federal Insecticide, Fungicide, and Rodenticide Act
HA
Health Advisory
HRL
Health Reference Level
HHBP
Human Health Benchmarks for Pesticides
IMOA
International Molybdenum Association
IOM
Institute of Medicine
IRIS
Integrated Risk Information System
ITIA
International Tungsten Industry Association
LD50
Median Lethal Dose
LOAEL
Lowest Observed Adverse Effect Level
MCLG
Maximum Contaminant Level Goal
MIG
Manganese Interest Group
MTBE
Methyl tertiary butyl ether
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NAB
NAWQA
NDWAC
MDBP
MDL
NOAEL
NPDES
NPDWR
NRC
NTP
OCSPP
OPP
OPPT
ORD
OW
PCCL
PCCL3
PCCL 4
OGWDW
PBPK
PFAS
PFBA
PFBS
PFDA
PFDoA
PFEESA
PFHpA
PFHpS
PFHxA
PFHxS
PFMBA
PFMPA
PFNA
PFOA
PFOS
PFPeA
PFPeS
PFTA
PFTrDA
PFUnA
PPCPs
PPRTV
PWS
RfD
National Advisory Board
National Ambient Water Quality Assessment
National Drinking Water Advisory Council
Microbial and Disinfection Byproduct
Method Detection Limit
No Observed Adverse Effect Level
National Pollutant Discharge Elimination System
National Primary Drinking Water Regulation
National Research Council
National Toxicology Program
Office of Chemical Safety and Pollution Prevention
Office of Pesticide Programs
Office of Pollution Prevention and Toxics
Office of Research and Development
Office of Water
Preliminary-CCL
EPA's Third Preliminary-CCL
EPA's Fourth Preliminary-CCL
Office of Ground Water and Drinking Water
Physiologically-Based Pharmacokinetic
Per-and Polyfluoroalkyl Substances
Perfluorobutanoic Acid
Perfluorobutanesulfonic Acid
Perfluorodecanoic Acid
Perfluorododecanoic Acid
Perfluoro (2-ethoxyethane) Sulfonic Acid
Perfluoroheptanoic Acid
Perfluoroheptanesulfonic Acid
Perfluorohexanoic Acid
Perfluorohexanesulfonic Acid
Perfluoro-4-methoxybutanoic Acid
Perfluoro-3-methoxypropanoic Acid
Perfluorononanoic Acid
Perfluorooctanoic Acid
Perfluorooctanesulfonic Acid
Perfluoropentanoic Acid
Perfluoropentanesulfonic Acid
Perfluorotetradecanoic Acid
Perfluorotridecanoic Acid
Perfluoroundecanoic Acid
Pharmaceuticals and Personal Care Products
Provisional Peer-Reviewed Toxicity Values
Public Water System
Reference Dose
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SAB
Science Advisory Board
SDWA
Safe Drinking Water Act
SMCL
Secondary Maximum Contaminant Level
SRMD
Standards and Risk Management Division
SWTR
Surface Water Treatment Rule
SYR
Six Year Review
TOF
Total Organic Fluorine
TRI
Toxics Release Inventory
TSCA
Toxic Substances Control Act
UCMR
Unregulated Contaminant Monitoring Rule
UCMR 1
First Unregulated Contaminant Monitoring Rule
UCMR 2
Second Unregulated Contaminant Monitoring Rule
UCMR 3
Third Unregulated Contaminant Monitoring Rule
UCMR 4
Fourth Unregulated Contaminant Monitoring Rule
U.S.
United States
USGS
United States Geological Survey
USEPA
United States Environmental Protection Agency
WHO
World Health Organization
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1. Introduction and Overview
Background
The Safe Drinking Water Act (SDWA) section 1412(b)(l)(B)(i), 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 National Primary Drinking Water Regulations (NPDWRs), are
known, or anticipated to occur in public water systems (PWSs) and may require regulation under the
SDWA. EPA uses this list of unregulated contaminants to help identify priority contaminants for
regulatory decision making and to prioritize research and data collection efforts. SDWA also requires the
agency to consult with the scientific community, including the Science Advisory Board (SAB), and
provide notice and opportunity for public comment prior to the publication of the final CCL. In addition,
SDWA 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 implemented an improved CCL process and published the Draft CCL 5 on July 19, 2021 (86 FR
37948) which included 81 contaminants or groups. The list is comprised of 69 chemicals or chemical
groups which include 66 chemicals recommended for listing by evaluation teams, one group of
cyanotoxins, one group of disinfection by products (DBPs), and one group of PFAS chemicals. The list
also included 12 microbes; specifically, 8 bacteria, 3 viruses, and 1 protozoa that were recommended for
listing based on the scores for waterborne outbreaks, occurrence and health effects, and
recommendations from various experts. EPA requested comments on the contaminants included on the
Draft CCL 5 and on improvements to the CCL 5 process. The public comment period closed on
September 17, 2021.
EPA specifically sought public comment on the following: contaminants selected for the Draft CCL 5;
data that EPA obtained and evaluated for developing the draft CCL 5; and improvements EPA
implemented in the CCL process. After considering comments, EPA developed the Final CCL 5 and
provided rationale and clarification to the CCL 5 process.
Who Submitted Comments
A total of 54 unique comments were received from the public via postings to www.regulations.gov,
under docket ID No. EPA-HQ-OW-2018-0594. There was one letter issued from a mass mailing campaign
from the Environmental Working Group containing over 9,000 signatures and another over 2,000
identical comments from private citizens urging EPA to reverse the decision not to regulate perchlorate.
All comments received that were related to CCL are included and addressed in this response to
comment document. Referenced supporting documents can be found in the CCL 5 public dockets at
https://www.regulations.gov along with any comment submitted on the draft CCL5, which can be read
as it appears within the commenter's original letter, email or posting.
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Exhibit 1. Categorizes comments by organization
type.
Organization Type
Count of Comments
Anonymous/Private Citizens
33
Drinking Water Organization
4
Environmental Groups
4
Industry Representatives
10
Non-Profit Organization
1
State Agency (1 letter representing 14 states
and District of Columbia)
2
Total
54
Science Advisory Board
In addition to public comment, a Science Advisory Board (SAB) Drinking Water Committee (DWC) was
augmented and conducted a review of EPA's fifth Drinking Water Contaminants Candidate List (CCL 5).
The SAB reviewed EPA's Draft Fifth Drinking Water Contaminant Candidate List (CCL 5) (86 FR 37948)
and three associated support documents: (1) Technical Support Document for the Draft Fifth
Contaminant Candidate List (CCL 5) - Contaminant Information Sheets; (2) Technical Support Document
for the Draft Fifth Contaminant Candidate List (CCL 5) - Chemical Contaminants; and (3) Technical
Support Document for the Draft Fifth Contaminant Candidate List (CCL 5) - Microbial Contaminants.
The SAB's subject matter experts provided comments and recommendations in response to EPA's
charge questions in a Report "Review of the EPA's Draft Fifth Contaminant Candidate List (CCL 5)" issued
on August 19, 2022 (USEPA, 2022d).
Comment Organization
Each set of public comments was assigned a unique Document ID in the CCL 5 public docket. The
Document ID is the CCL 5 Docket ID No. (EPA-HQ-OW-2018-0594) with an additional four-digit identifier.
For example, comment number 51 has the Document ID EPA-HQ-OW-2018-0594-0051. Prior to
receiving any comments via the public docket, EPA posted 50 documents to support the Draft CCL. Thus,
the first public comment received is number 51, the second is 52, etc. Exhibit 2 provides the Document
ID, corresponding comment number, and submitter information for all comments received. Clicking the
blue hyperlinked Document ID for each comment in Exhibit 2 will take the reader to the original
comment submission in the public docket, where additional information can be viewed, such as tables,
figures, attachments, and references that may have been included within the context of the original
submission. If such additional information was included with a comment, EPA has provided a note
within the comment text (presented in Section 2 of this document) and the Document ID link. If
footnotes were used, they are provided within the comment text as [FN#: ]. The original comment
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submissions can also be accessed by searching for the associated Document ID on
https://www.regulations.gov/ under Docket ID No. EPA-HQ-OW-2018-0594.
EPA's Categorization of Public Comments and Document Organization
Each set of comments were read by EPA and assigned a topic code, as appropriate. Comment excerpts
from different stakeholders that addressed similar subjects were then grouped under the corresponding
topic.
Section 2 of this document presents the public comments and EPA responses by topic. EPA developed
an Agency Topic Discussion to collectively address the comments received on each topic, which appears
at the beginning and summarizes each topic section. Throughout this document, the Agency Topic
Discussions have a green header and background. Following the Agency Topic Discussion are comment
excerpts assigned to the topic, organized numerically by comment number. No grammatical or spelling
edits were made to the text of the comments received; they are presented in this document verbatim.
The comment excerpts for each topic and their corresponding responses are presented under a blue
header and have a white background. Clicking on the blue hyperlinked comment number appearing at
the beginning of each excerpt will take the reader to Exhibit 2, which presents the full Document ID,
submitter name, and organization. Exhibit 2 should be referenced for the full list of commenters and a
link to the original comment submission in the CCL 5 public docket. Each comment excerpt is followed
by an Individual Response from EPA, which directs the reader to the associated Agency Topic
Discussion(s) and, where appropriate, provides supplemental comment-specific responses that may not
be addressed in the Agency Topic Discussion. Clicking on the blue hyperlinked topic(s) in the Individual
Response will digitally direct the reader to the corresponding Agency Topic Discussion(s) in this
document.
Cross Referencing of Responses
Comment excerpts that addressed multiple topics within a sentence or paragraph could not practically
be divided. For these excerpts, EPA has identified and digitally cross referenced all associated Agency
Topic Discussions in the Individual Responses to provide clarity, avoid redundancy, and ensure
consistency. If a response for a comment excerpt cross references multiple discussions, the excerpt is
only presented under one of those topics (i.e., the most relevant topic). This is to improve readability
and ensure that all comments are included in entirety only once in this document. It is important to note
that while most Agency Topic Discussions address multiple comments, not all related excerpts are
presented thereafter; related excerpts in other sections throughout the document instead digitally cross
reference that specific discussion in their Individual Response.
Exhibit 2: List of Public Commenters
Comment Information
Submitter Information
Commenter
Number
Document ID
First Name
Last Name
Organization Name
51
EPA-HQ-OW-2018-0594-0051
The Ranger Leadership
and Policy Center
52
EPA-HQ-OW-2018-0594-0052
Alicia
Johnston
Private Citizen
53
EPA-HQ-OW-2018-0594-0053
Anonymous
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Exhibit 2: List of Public Commenters
Comment Information
Submitter Information
Commenter
Number
Document ID
First Name
Last Name
Organization Name
54
EPA-HQ-OW-2018-0594-0054
Anonymous
55
EPA-HQ-OW-2018-0594-0055
Anonymous
56
EPA-HQ-OW-2018-0594-0056
Brian
Callahan
Private Citizen
57
EPA-HQ-OW-2018-0594-0057
W.L.
Leow
Private Citizen
58
EPA-HQ-OW-2018-0594-0058
Anonymous
59
EPA-HQ-OW-2018-0594-0059
Anonymous
60
EPA-HQ-OW-2018-0594-0060
Khemmarin
Ortez
Private Citizen
61
EPA-HQ-OW-2018-0594-0061
Kexin
Yu
Private Citizen
62
EPA-HQ-OW-2018-0594-0062
Karen
Benavente
Private Citizen
63
EPA-HQ-OW-2018-0594-0063
Michael
Vicars
Private Citizen
64
EPA-HQ-OW-2018-0594-0064
Elizabeth
Rice
Private Citizen
65
EPA-HQ-OW-2018-0594-0065
Anonymous
66
EPA-HQ-OW-2018-0594-0066
Angela
Pesquiera
Private Citizen
67
EPA-HQ-OW-2018-0594-0067
Justin
Prendergast
Private Citizen
68
EPA-HQ-OW-2018-0594-0068
International Tungsten
Industry Association
(ITI A)
69
EPA-HQ-OW-2018-0594-0069
Jason
Lowery
Private Citizen
70
EPA-HQ-OW-2018-0594-0070
National Ground
Water Association
(NGWA)
71
EPA-HQ-OW-2018-0594-0071
Diane
VanDe Hei
Association of
Metropolitan Water
Agencies (AMWA)
72
EPA-HQ-OW-2018-0594-0072
Arkema, Inc.
73
EPA-HQ-OW-2018-0594-0073
Stephen
Risotto
American Chemistry
Council (ACC)
74
EPA-HQ-OW-2018-0594-0074
Cobalt Institute (CI)
75
EPA-HQ-OW-2018-0594-0075
J. Alan
Roberson
Association of State
Drinking Water
Administrators
(ASDWA)
76
EPA-HQ-OW-2018-0594-0076
Attorneys General of
the States of
Connecticut, Delaware,
Iowa, Maine,
Maryland,
Massachusetts,
Minnesota, New
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Exhibit 2: List of Public Commenters
Comment Information
Submitter Information
Commenter
Number
Document ID
First Name
Last Name
Organization Name
Jersey, New Mexico,
New York, Oregon,
Pennsylvania, Virginia,
and Wisconsin, and
the District of
Columbia
77
EPA-HQ-OW-2018-0594-0077
G. Tracy
Mehan
American Water
Works Association
(AWWA)
78
EPA-HQ-OW-2018-0594-0078
3M Company
79
EPA-HQ-OW-2018-0594-0079
Paul
Nyffeler
Private Citizen
80
EPA-HQ-OW-2018-0594-0080
Terrence
Thrweatt Jr.
Private Citizen
81
EPA-HQ-OW-2018-0594-0081
Louisiana Chemical
Association (LCA)
82
EPA-HQ-OW-2018-0594-0082
Manganese Interest
Group (MIG)
83
EPA-HQ-OW-2018-0594-0083
David
Andrews
Earthjustice
84
EPA-HQ-OW-2018-0594-0084
D. Lee
Currey
Maryland Department
of the Environment
85
EPA-HQ-OW-2018-0594-0085
Stephen
Wilhelm
Chloropicrin
Manufacturers' Task
Force (CMTF)
86
EPA-HQ-OW-2018-0594-0086
John
Hilbert
Vanadium Producers
and Reclaimers
Association (VPRA)
87
EPA-HQ-OW-2018-0594-0087
Daniel
Estrin
Waterkeeper Alliance
88
EPA-HQ-OW-2018-0594-0088
Silent Spring Institute
89
EPA-HQ-OW-2018-0594-0089
Natural Resources
Defense Council
(NRDC)
90
EPA-HQ-OW-2018-0594-0090
Bill
Isler
Simmons
Private Citizen
91
EPA-HQ-OW-2018-0594-0091
Carter
Phillips
Private Citizen
92
EPA-HQ-OW-2018-0594-0092
Anonymous
93
EPA-HQ-OW-2018-0594-0093
Michelle
Garrigan
Private Citizen
94
EPA-HQ-OW-2018-0594-0094
Rebecca
Potvin
Private Citizen
95
EPA-HQ-OW-2018-0594-0095
Adam
Nelson
Private Citizen
96
EPA-HQ-OW-2018-0594-0096
Ned
Rollins
Private Citizen
97
EPA-HQ-OW-2018-0594-0097
Josephine
Scipione
Private Citizen
98
EPA-HQ-OW-2018-0594-0098
Anonymous
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Exhibit 2: List of Public Commenters
Comment Information
Submitter Information
Commenter
Number
Document ID
First Name
Last Name
Organization Name
99
EPA-HQ-OW-2018-0594-0099
Anonymous
100
EPA-HQ-OW-2018-0594-0100
Dan
Man
Private Citizen
101
EPA-HQ-OW-2018-0594-0101
Mass comment
campaign - unknown
sponsoring
organization
102
EPA-HQ-OW-2018-0594-0102
Mass comment
campaign -
Environmental
Working Group (EWG)
103
EPA-HQ-OW-2018-0594-0103
Princess
Eterna
Private Citizen
104
EPA-HQ-OW-2018-0594-0104
International
Molybdenum
Association (IMOA)
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2. Comments and EPA Responses by Topic
General Comments
Agency Discussion on General Comments
Agency Topic Discussion:
EPA received many general comments related to the Draft Fifth Contaminant Candidate List (CCL 5),
including comments supporting EPA's mission of protecting human health by continuing to regulate
contaminants in drinking water and identifying drinking water contaminants that may require
regulation. The Agency agrees that protecting the quality of drinking water is an important part of
protecting public health and appreciates the commenters' support for the Contaminant Candidate List
(CCL) process and the drinking water program.
A couple of commenters refer to CCL as a regulation. The CCL is not a regulation or a proposed
regulation. It has no binding effect and is not enforceable. Section 1412(b)(1) of the Safe Drinking
Water Act (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
National Primary Drinking Water Regulations (NPDWRs), are known or anticipated to occur in public
water systems (PWSs) and may require regulation under the SDWA. The SDWA also directs EPA 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 uses the CCL to help identify priority contaminants for regulatory decision making and to
prioritize research and data collection efforts. On a five-year cycle, under a separate action, known as
the regulatory determination process, the SDWA requires EPA to make decisions on whether it should
initiate a process to develop an NPDWR for no fewer than five contaminants on the CCL. Under
Section 1412 (b)(1)(a) of SDWA, EPA makes a determination to regulate a contaminant in drinking
water if the Administrator determines that it meet the three following criteria:
1. The contaminants may have an adverse effect on the health of persons;
2. The contaminant is known to occur or there is substantial likelihood that the contaminant will
occur in public water systems with a frequency and at levels of public health concern and;
3. In the sole judgement 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 must publish a proposed Maximum Contaminant Level Goal
(MCLG) and NPDWR within 24 months. After proposal, the Agency must publish the final MCLG and
promulgate final NPDWR (SDWA section 1412 (b)(1)(E) within 18 months. (These deadlines may be
extended by 9 months.)
Comments related to regulated contaminants in drinking water, such as lead, and developing new
regulations for contaminants are outside the scope of the CCL. EPA continues to value and encourage
partnerships that benefit local water systems and foster strong partnerships with other federal
agencies, tribes, local governments, and states. EPA's regional offices play a significant role in
supporting states in implementing NPDWRs.
One comment suggest that EPA make a more easily digestible document for the public. The Agency
has developed a Technical Support Document for the Final Fifth Contaminant Candidate List (CCL 5) -
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Agency Discussion on General Comments
Chemical Contaminants (USEPA, 2022a); Technical Support Document for the Final Fifth Contaminant
Candidate List (CCL 5) - Contaminant Information Sheets (USEPA, 2022b); and Technical Support
Document for the Final Fifth Contaminant Candidate List (CCL 5) - Microbial Contaminants (USEPA,
2022c)_that outlines in detail with diagrams, figures and exhibits that assist with explaining various
parts of the CCL 5 process. Between the Draft CCL 5 and the Final CCL 5, the Agency took steps, where
possible, to increase clarity and transparency of these technical support documents based on public
comments and SAB recommendations. EPA will continue to work to improve materials and
information to make the process clearer and more concise with each CCL cycle.
In addition, as described in the Technical Support Document for the Final Fifth Contaminant
Candidate List (CCL 5) - Microbial Contaminants, the Agency considers a broad range of microbes,
known as the CCL microbial universe, to identify those pathogens that present the greatest public
health concern related to health risks and occurrence in drinking water to list on the CCL. The Human
Coronavirus (SARS-COV-2), the virus that causes COVID, was included in the CCL 5 Microbial Universe
and processed through the microbial screening process. Using the exclusionary screening criteria
developed for CCL microbial pathogens, SARS-CoV-2 was screened out using Criterion 6: Pathogens
transmitted solely by respiratory secretions. The World Health Organization (WHO) has stated that
the "presence of the COVID-19 virus has not been detected in drinking-water supplies and based on
current evidence the risk to water supplies is low" (WHO, 2020). As mutations of the Human
Coronavirus may occur over time, EPA will continue to research species that could potentially be
found in drinking water. During each CCL process, which occurs every five years, there is an effort to
evaluate any new information/data on contaminants and identify any new contaminants for
evaluation through the CCL process for listing and/or as a potential as a research priority. For more
details about Coronavirus and Drinking Water please see EPA's Coronavirus and Drinking Water and
Wastewater webpage: https://www.epa.gov/coronavirus/coronavirus-and-drinking-water-and-
wastewater.
Comments Received on General Comments
Comment Excerpt from Commenter 52
The population in the United States relies on the EPA to continue to regulate the water that they use
for drinking, cooking, bathing, and even watering their own gardens that they use to grow their own
foods. The general public is unaware of the many different types of contaminants that could
negatively effect the health of themselves and their families and relies on the experience of the
scientists that make the CCL to identify the contaminants that could be harmful to their health and to
continue to regulate the previously identified contaminants and identify contaminants that requires
regulation.
Individual Response: Please see Discussion on General Comments.
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Comments Received on General Comments
Comment Excerpt from Commenter 54
The Draft CCL 5 includes an additional 81 contaminants or groups. The list is comprised of 69
chemicals or chemical groups and 12 microbes. Since 1998, the CCL listing has been revised to include
the contaminants that pose the greatest public health concern. In this recent draft I would ask if there
was research indicative of contaminants that may have come about due to the recent coronavirus
global pandemic. The pandemic has caused a rise in unemployment and a review of this data may be
important to ascertain if we have enough or appropriate number of resources still reviewing or
monitoring the data sources. Also, the recent changes in climate could have also taken a toll on our
drinking water exposure.
Individual Response: Please see Discussion on General Comments.
EPA compiled data sources identified from CCL 3 and CCL 4, along with data sources recommended by
the CCL 5 workgroup and subject matter experts. As a result of this effort, EPA identified 134
potential data sources and further assessed their potential use for the CCL 5 development process.
More information on Assessing and Identifying Data Sources can be found in section 2.2 of the
Technical Support Document for the Final Fifth Contaminant Candidate List (CCL 5) - Chemical
Contaminants (USEPA, 2022a).
EPA agrees that changes in climate may affect drinking water quality as a result of an increase in the
frequency and intensity of storms and warmer air temperatures. More frequent storms and floods
may cause overflows from sewage systems and treatment plants into freshwater sources for drinking
water. This may lead to an increase in the prevalence of waterborne parasites, such as
Cryptosporidium and Giardia. Additionally, higher air temperatures, and the corresponding increase in
water temperatures, can also promote increased growth of algae and cyanobacteria in some
waterbodies causing harmful algal blooms (HABs). An increase in HABs can threaten availability of
source water, impact drinking water quality and increase the need for drinking water treatment.
Comment Excerpt from Commenter 58
As a consumer and a private citizen, I do not know many things about chemical compounds and what
good or bad they can do for my body. However, I know that many contaminants can naturally occur in
the water and also could happen as a chemical byproduct. I am really glad that this agency is adding
more chemical groups and contaminants, that are currently not subject to any regulations to this
proposed CCL 5 regulation.
It is really important to recognize contaminants because the adverse effects of those contaminants
are not known to the health of the person. This regulation would be a good opportunity for reducing
health risks for persons served by public water systems.
Individual Response: Please see Discussion on General Comments and Contaminant Groups.
Comment Excerpt from Commenter 59
Re: Document Citation 86 FR 37948
To whom it may concern:
Thank you for the opportunity to comment on document citation 86 FR 37948. As a PhD scientist with
a Masters in Public Health, I appreciate the efforts of the EPA and support the continuation of your
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on General Comments
three step process of (1) building a broad universe of contaminants and microbes; (2) screening this
universe to identify those that need more scrutiny, and (3) selecting what makes the list based on
human health effects. I also appreciate the utilization of subject matter experts from the NAB, NRC,
NDWAC and the public in the continuous identification of contaminants and determination of future
regulatory actions on these contaminants. The general public depends on these subject matter
experts to identify contaminants that may negatively affect their health.
Individual Response: Please see Discussion on General Comments.
Comment Excerpt from Commenter 60
As a regular user of water, like many other Americans, it is imperative that the EPA continue to
generate the Containment Candidate List (CCL) which the Safe Drinking Water Act (SDWA) mandates
is published every five years. After reviewing the lists of different contaminants in our water, the EPA
has done a thorough job of listing and also providing explanations to the public of what these
contaminants are so it is easier for the public to understand.
The list can be intimidating to some and also has the ability to put fear of drinking water into others.
Though I understand that simplifying most of the list for the general public is difficult, there should be
a way to provide a more general breakdown of the list to everyone. Unfortunately, in the U.S. there
are areas where water contamination is terrible, thankfully this is not the norm.
I appreciate the publishing of this list since 1996 and hope the EPA continues to do so, in hopes that
efforts are made to continue to make our water safer for everyone. I propose the EPA make a more
easily digestible document for the public, maybe one with pictures and explanations so all can learn
from it and have any fears set aside. Thank you.
Individual Response: Please see Discussion on General Comments.
Comment Excerpt from Commenter 61
The proposed rule that regulates 66 chemicals, 3 chemical groups (per-and polyfluoroalkyl substances
(PFAS), cyanotoxins, and disinfection byproducts) and 12 microbial contaminants. I fully support the
regulation of chemicals in drinking water which might affect human health . I understand EPA has
followed 3 three-step processes to classify and select the Draft CCL5 chemicals. The last step was to
select contaminants based on occurrence in drinking water. Based on the ERA previous
announcement, tap water is still safe to drink during Covid-19 pandemic. It has raised my concern
that the select contaminants are based on the occurrence or score in drinking water. For viruses like
SARS, Coronavirus, and its mutations, they are very contiguous and it may have a huge effect on
human health, but may not be found in the drinking water now. It raises the question if we have
enough resources and techniques to analyze and monitor the data.
Individual Response: Please see Discussion on General Comments and Suggestions to Improve the
Process for Future CCLs.
Comment Excerpt from Commenter 65
The current coronavirus pandemic is resulting in significant impacts worldwide in many aspects. It has
been causing major drawbacks in terms of environmental protection policies around the global. For
example, with the fear of COVID-19 transmission, people increased use of single-us plastic,
disinfecting products and related chemicals - hand sanitizers, sanitizing wipes, toilet papers, cleaning
products and tissue, therefore, it caused increased environmental water pollution concerns. One of
the main routes of human exposure to pollutants is through our drinking water. It is important for
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on General Comments
EPA to focus on and add certain pollutants considered major contaminants in drinking water which
are expected to show increased levels during and after the COVI-19 pandemic and result in adverse
effects to human's immune system into the list of regulated chemicals.
Individual Response: Please see Discussion on General Comments.
Comment Excerpt from Commenter 77
The American Water Works Association (AWWA) appreciates the opportunity to provide comments
on the Environmental Protection Agency's (EPA's) draft of the Drinking Water Contaminant Candidate
List 5 (CCL 5). AWWA has a continuing interest in EPA's Safe Drinking Water Act (SDWA) program and
has been an active participant in, and facilitator of, technical dialogues and stakeholder engagement
around the drinking water regulatory process since its inception.
The CCL is the element of the nation's drinking water program that helps EPA identify contaminants
that represent public health risks that can be reduced through drinking water treatment / control. As
such it provides the starting point for identifying regulatory and research / information collection
priorities for EPA, the federal government, and the sector. Consequently, it is important to recognize:
1. The work of the involved EPA staff and peer-reviewers on the CCL is vitally important and
should be recognized by EPA management.
2. For the CCL to be an effective tool it must be a short, preferably prioritized, list. Given EPA's
available resources, the draft CCL 5 is not yet sufficiently focused.
3. The Final CCL 5 Federal Register notice will be a key opportunity to present research and
information needs to advance EPA's drinking water regulatory program.
4. CCL 5 and subsequent CCLs should be used to inform coordination with other EPA programs
(e.g., the Toxic Substances Control Act program [TSCA]) in order to prevent contamination of the
nation's water supply.
5. The draft CCL 5 technical support document suggests that there are significant gaps in data
that should be available from the TSCA program and the Clean Water Act National Pollutant Discharge
Elimination System. EPA should take steps now to address these gaps - action may be needed by the
TSCA and Office of Enforcement and Compliance program offices to facilitate development of future
CCLs.
6. The CCL process should be an ongoing effort rather than the current prepare-pause-
regenerate preparation model and that ongoing effort should be in concert with external expert
input.
7. The Draft CCL 5 Federal Register notice and technical support documents should be
supplemented to better communicate the effect of influential decisions in CCL preparatory process,
especially the identification of named groups rather than individual contaminants.
8. The CCL is an important and underutilized tool in EPA's risk communication efforts. A clearly
described and supported prioritized list of contaminants would provide a framework for EPA
communication about its efforts to protect the public from contaminants in drinking water
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EPA-OGWDW
Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on General Comments
AWWA hopes that the following comments will assist EPA to utilize this important element of SDWA
effectively. If you have any questions regarding this correspondence, please contact me or Chris
Moodyat 202.326.6127 or cmoody@awwa.org.
FOR THE AMERICAN WATER WORKS ASSOCATION.
G. Tracy Mehan, III
Executive Director - Government Affairs
American Water Works Association
Attachment (1)
cc: Michal Freedhoff, EPA/OCSPP
Andrew Sawyers, EPA/OW/OWM
Jennifer McLain, EPA/OW/OGWDW
Randy Hill, EPA/OECA/ETDD
Madeline Beal, EPA/OPA
Kesha Forrest, EPA/OW/OGWDW
Who is AWWA
The American Water Works Association (AWWA) is an international, nonprofit, scientific and
educational society dedicated to providing total water solutions assuring the effective management
of water. Founded in 1881, the Association is the largest organization of water supply professionals in
the world. Our membership includes more than 4,500 utilities that supply roughly 80 percent of the
nation's drinking water and treat almost half of the nation's wastewater. Our 50,000-plus total
membership represents the full spectrum of the water community: public water and wastewater
systems, environmental advocates, scientists, academicians, and others who hold a genuine interest
in water, our most important resource. AWWA unites the diverse water community to advance public
health, safety, the economy, and the environment.
ATTACHMENT A
Comments prepared by the
American Water Works Association
on the
U.S. Environmental Protection Agency's
Drinking Water Contaminant Candidate List 5-Draft
(86 Federal Register 37948, Docket ID: EPA-HQ-OW-2018-0594)
Prepared
September 17, 2021
Contents
Introduction 1
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EPA-OGWDW Draft CCL 5 Response to Comments EPA 815-R-22-001
October 2022
Structuring a More Effective CCL 5 1
Short, Manageable List is Needed 2
Communicate Priorities Within CCL 2
Lack of Information Characterizing Wastewater Discharges 3
Using CCL to Advance Source Water Protection 3
CCL Development Process 4
Coordination with Other SDWA Processes 4
External Peer-Review 4
Contaminant Information Sheets 4
Transparency 5
Specific CCL 5 Contaminants 9
Appropriately Define PFAS 9
Inclusion of Mycobacterium avium and M. abscessus 10
Cyanotoxins 10
Conclusion 11
Comments
Prepared by the American Water Works Association on
EPA's Drinking Water Contaminant Candidate List 5-Draft
(86 Federal Register 37948, Docket ID: EPA-HQ-OW-2018-0594)
Introduction
AWWA has commented extensively on prior contaminant candidate lists (CCLs) and their
development. [FN1: AWWA, 2009, Comment submitted on Drinking Water Contaminant Candidate
List 3 - Draft, EPA-HQ-OW-2007-1189-0100.] [FN2: AWWA, 2012. AWWA Response to Contaminant
Candidate list 4 Request for Nominations, Docket ID No. EPA-HQ-OW-2012-0217.
https://www.regulations.gov/comment/EPA-HQ-OW-2012-0217-0059] In its Draft CCL 5 Federal
Register notice EPA solicited comments on the following:
1. Contaminants selected for the Draft CCL 5, including any supporting data that can be used in
developing the Final CCL 5.
2. Data that EPA obtained and evaluated for developing the Draft CCL 5 may be found in the
Chemical Technical Support Document and Microbial Technical Support Document located in the
docket for this document.
3. The improvements EPA implemented in the CCL 5 process.
The following comments are focused on these areas.
AWWA appreciates that EPA's approach in developing the draft CCL 5 and implementing
recommendations from the National Drinking Water Advisory Council (NDWAC), AWWA, and others.
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on General Comments
The process described in the proposal is thorough and provided for consideration of large universe of
potential candidate contaminants. The Agency clearly recognizes that the development of the CCL
should be a comprehensive and methodical process. The CCL process is an important component of
the Agency's Safe Drinking Water Act (SDWA) work plan and is essential to moving beyond regulating
the "contaminant du jour". A well-crafted CCL is essential to informing future risk management
actions that effectively utilize scarce resources to best protect public health.
Structuring a More Effective CCL 5
As described by the SDWA, the CCL is the first step of the regulatory process for drinking water
contaminants and is intended to represent the contaminants that "present the greatest public
concern". To be an effective tool, the CCL must provide adequate focus to drinking water research
needs. When effectively developed and structured, the CCL guides EPA and external stakeholders to
conduct research important to addressing risks associated with drinking water risks, and thus
informing action under SDWA when needed.
The CCL should also facilitate clear communication with consumers and engaged stakeholders on
research gaps limiting further regulatory action, the scope of the necessary research projects (short-,
mid-, and long-term), and the relative levels of priority that contaminants present as a public health
risk. The CCL is revised on a five-year cycle so that the list reflects changes in available science and the
relative risks presented by unregulated contaminants. For example, the national occurrence of a
listed contaminant may decrease due to management efforts under the Toxic Substances Control Act
(TSCA), state regulatory actions, or changes in manufacturing and use trends. Alternatively,
contaminants not previously on the CCL due to a limited availability of data may be added to the CCL
due to new data that show the contaminant presents a greater public concern.
Individual Response: Please see Discussion on General Comments. Length of CCL 5. Other Drinking
Water Programs. Other EPA Programs. Chemical Data/Data Sources, and Contaminant Groups.
Comment Excerpt from Commenter 95
I appreciate the ability to comment on this upcoming regulation. I feel like this is a great thing to be
doing, as it notifies the public of these 66 new chemicals. I noticed that none of these 66 chemicals
are being regulated by the EPA in any way, and am curious if the EPA tests these chemicals to see if
they are a danger to human health? I noticed that there are specific effects listed for the bacterial
contaminants and pathogens listed in the regulation, however I am curious what the EPA is doing to
attempt to combat these rising new bacteria that are found in our drinking water.
Individual Response: Please see Discussion on General Comments and Draft CCL 5-Microbes. EPA
respectfully disagrees with the commenter's statement that "none of the 66 chemicals are being
regulated by the EPA in any way". The 66 individually listed chemicals on the CCL 5 are currently not
regulated under the SDWA with a National Primary Drinking Water Regulation (NPDWR); however,
some of the chemicals listed on the CCL 5 are regulated under other EPA regulatory programs. For
example, EPA regulates 2,4-dinitrophenol under the Clean Water Act's national permitting program
and regulates all pesticides listed on CCL 5, such as diazinon and dicrotophos, under the Federal
Insecticide, Fungicide, and Rodenticide Act.
Regarding the question on human health, almost all except for four contaminants (4- Methyl tert-
butyl ether (MTBE), Nonylphenol (all isomers), Desvenlafaxine, and Fluconazole) of the CCL 5 listings
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EPA 815-R-22-001
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Comments Received on General Comments
have available health effects information or qualifying health assessments developed by EPA or other
health agencies. Further, EPA works to prioritize research on CCL contaminants. EPA conducts
research including toxicity testing, computational toxicology approaches, and the development of
new approach methods to fill data gaps in support of Agency regulatory needs. EPA also conducts
research on microbial contaminants including exposure, dose-response, and treatment studies.
Results from this research can help inform future decisions on CCL 5 listed contaminants. For
additional information on data availability, please see the Technical Support Document for the Final
Fifth Contaminant Candidate List (CCL 5) - Chemical Contaminants, Table 26.
Comment Excerpt from Commenter 99
As an Environmental Policy student, I agree with the EPA's mission of protecting human health and
the American public. Through this improvement of the draft list within the Safe Drinking Water Act
(SDWA), the agency is placing a greater priority on the health and safety of Americans. As the
chemical manufacturing industry grows and mitigation of chemicals in the landscape becomes more
difficult, this type of Contaminant Candidate List is ever more pertinent. The continuation and update
to this program are needed more than ever to protect people, especially those who live in agricultural
and manufacturing adjacent communities.
Individual Response: Please see Discussion on General Comments.
Comment Excerpt from Commenter 100
This is a good reason why people should be safe, not even water is considered safe, especially if its
contaminated, it could seriously get someone hurt.
Individual Response: Please see Discussion on General Comments.
Comment Excerpt from Commenter 101
Thank you for this opportunity to comment on EPA's draft Fifth Contaminant Candidate List (Draft CCL
5) under the Safe Drinking Water Act (SDWA). I support EPA regulating all of the dangerous
contaminants on the SDWA candidate list. It is especially important that EPA include and set safe
drinking water limits on groups of extremely hazardous chemicals like cyanotoxins, disinfection
byproducts, and PFAS.
Accessing safe drinking water has been a concern of mine for many years. When my children were
preschoolers and tested high for lead, I became very aware of the importance of being vigilant about
the quality of the water we were drinking. We should be able to depend on the quality of water
coming out of our taps. We need agencies like the EPA to work with our local governments to provide
strong guidelines for safety.
We need EPA to ensure our drinking water is safe from all of the toxic and hazardous chemicals that
are being released into the environment. To do that, EPA must increase staffing and speed up the
process for reviewing the contaminants and setting legal limits on how much can be in our drinking
water.
Individual Response: Please see Discussion on General Comments. Chemical Groups. PFAS. DBPs. and
Cyanotoxins.
Comment Excerpt from Commenter 102
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on General Comments
The undersigned 9,292 supporters of the Environmental Working Group, or EWG, add their voices to
EWG's comments calling for regulating hazardous drinking water contaminants.
9,292 supporters signed EWG's petition stating:
Clean up our water! Chemicals linked to cancer, hormone disruption and infertility should not be
allowed in our water. It's time for the EPA to do its job and regulate hazardous drinking water
contaminants like PFAS, pesticides and disinfection byproducts.
EWG and our supporters urge you to take steps to clean up our drinking water.
Individual Response: Please see Discussion on General Comments, PFAS, and DBPs.
Length of CCL 5
Agency Discussion on Length of CCL 5
Agency Topic Discussion:
Section 1412(b)(1) of the Safe Drinking Water Act (SDWA), as amended in 1996, does not impose a
limit to the number of drinking water contaminants that may or should be included on a given CCL.
EPA's Science Advisory Board (SAB) report on the Third Contaminant Candidate List (CCL 3) noted,
however, that the process used for CCL 3 had "not whittled the Universe sufficiently to be efficient or
effective," with 104 contaminants identified for that iteration. The SAB report further noted that
larger CCLs could "not clearly communicate to the [drinking water community], other specific
interested parties, and/or the general public which contaminants might - or might not - be
considered for a meaningful regulatory determination" (USEPA, 2009b).
Based on SAB's feedback for CCL 3, EPA worked to deliver a shorter CCL 5 compared to its
predecessor. When considering that the improved CCL 5 process generated the broadest and most
comprehensive chemical universe of health and occurrence information to date (with approximately
22,000 chemicals and 1,435 microbes in the CCL 5 Universe compared to approximately 6,000
chemicals and 1,415 microbes in the CCL 3 Universe), EPA views the resulting list of 66 chemicals,
three chemical groups and 12 microbial contaminants as having been more effectively narrowed for
the purposes of identifying priority contaminants for both future regulatory decisions and for
prioritizing research and data collection efforts.
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EPA 815-R-22-001
October 2022
Comments Received on Length of CCL 5
Comment Excerpt from Commenter 71
The Association of Metropolitan Water Agencies (AMWA) is an organization representing the largest
publicly owned drinking water utilities in the United States. AMWA appreciates the opportunity to
comment on the Environmental Protection Agency's (EPA) draft Drinking Water Contaminant
Candidate List 5 (CCL 5). AMWA has continually supported the scientific and data-driven process
under the Safe Drinking Water Act (SDWA). The association believes following the process outlined in
the SDWA remains the best way to prioritize the agency's limited resources by focusing on those
contaminants most likely to present human health risks through drinking water while also being
conscious of the finite resources available to public water systems across the country. The CCL
process remains an essential first step for the agency to determine which contaminants should move
further through the SDWA process.
As AMWA has stressed in previous comments to the agency, the association believes that EPA should
focus the CCL in a way that will best utilize the agency's limited resources and optimize its resource
budget. AMWA maintains the need for EPA to reduce the number of substances included in each CCL.
The association believes that restricting the CCL to a more manageable number will better accomplish
the agency's goal of accurate and meaningful regulatory determinations for currently unregulated
substances.
The SDWA states that the Administrator shall regulate contaminants that will provide a "meaningful
opportunity for health risk reduction for persons served by public water systems" (§1412
(b)(l)(A)(iii)). EPA has maintained in (or throughout) previous statements that the SDWA does not
limit the number of contaminants that may be included in the CCL.
Although AMWA agrees with EPA's assessment that the SDWA does not limit to the size of the CCL, it
remains unclear how the agency can best prioritize these contaminants when the list grows
exponentially, yet EPA's budget to study emerging contaminants does not. For example, the number
of contaminants included more than doubled between CCL 2 and CCL 4, with 51 contaminants on the
list for CCL 2 and 109 contaminants on CCL 4. It appears that EPA has acknowledged this issue and
reduced the number of substances on this most recent CCL by not automatically carrying over all
chemicals from CCL 4 to CCL 5, but instead revisiting the available information for each contaminant
before including it again. AMWA encourages the agency to continue this procedure when creating
future CCLs to keep the list more manageable.
Individual Response: Please see Discussion on Length of CCL 5.
Comment Excerpt from Commenter 77
AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.
Short, Manageable List is Needed
The EPA Science Advisory Board observed that CCL 3, which included 116 contaminants was a list too
large to "achieve the stated objectives of the CCL process." [FN3: SAB. 2009. SAB Advisory on EPA's
Draft Third Drinking Water Contaminant Candidate List (CCL3).] As proposed, the Draft CCL 5 is
comprised of more than 1,400 individual contaminants. It is difficult, if not impossible, for
stakeholders and consumers to effectively understand the EPA's priorities moving forward with such
an extensive CCL. AWWA and other stakeholders have previously emphasized the need for a short,
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on Length of CCL 5
manageable CCL to facilitate the efficient advancement of research activities and to clearly
communicate potential contaminants that present opportunities for meaningful public health
protection. EPA should consider reducing the size of the CCL 5 such that only drinking water
contaminants presenting the "greatest public concern" are included on the list and that the list's
scope is commensurate with the funding available for EPA to deploy to advance SDWA decision-
making processes. Moreover, it's completely infeasible to meaningfully consider regulation for 1,400+
contaminants. This dilutes the impact of the CCL and suggests that listing doesn't truly have any
substantive significance to EPA's regulatory decision-making.
Individual Response: Please see Discussion on Length of CCL 5.
Other Drinking Water Programs
Agency Discussion on Other Drinking Water Programs
Agency Topic Discussion:
EPA received many comments related to the Unregulated Contaminant Monitoring Rule (UCMR) and
the Regulatory Determination process. The CCL, UCMR, and Regulatory Determinations are three
separate, but interrelated, steps in the drinking water regulatory process authorized under SDWA.
The selection of contaminants for previous or upcoming UCMR monitoring and prioritizing
contaminants on the CCL for regulatory determinations are both outside the scope of CCL 5.
The CCL is not a regulation and therefore there are no drinking water enforcement actions under
SDWA with respect to contaminants on the list. The statute does not authorize banning of
contaminants. EPA uses the CCL to identify priority contaminants for regulatory decision making and
information collection.
For contaminants that have sufficient information available, the Agency can proceed through the
regulatory determination process. Under that process, EPA determines whether the three statutory
criteria for regulation of a new drinking water contaminant are met for any contaminant not yet
regulated, the Agency may decide to develop a Health Advisory (HA), which provides non-regulatory
and non-enforceable concentration values for drinking water contaminants at which adverse health
effects are not anticipated to occur over specific exposure durations (one-day, ten-days, several
years, and a lifetime). HAs serve as informal technical guidance to assist Federal, State, and local
officials, and managers of public or community water systems (CWSs) in protecting public health, such
as when emergency spills or contamination situations occur.
UCMR
EPA received many comments related to previous and upcoming UCMR monitoring cycles. SDWA
section 1445(a)(2)(B)(i) requires that every five years EPA issue a new list of no more than 30
unregulated contaminants to be monitored by public water systems (PWSs).
In establishing the list of contaminants for each UCMR cycle, EPA considers the CCL and other priority
contaminants. This national occurrence study is one of the primary sources of occurrence data in
drinking water that the Agency uses to develop regulatory decisions for contaminants in the public
drinking water supply.
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October 2022
Agency Discussion on Other Drinking Water Programs
EPA selected UCMR contaminants using a multi-step prioritization process. The first step identified
contaminants that were not monitored under previous UCMR cycles; may have significant occurrence
nationally; and have a completed, validated drinking water analytical method. The next step focused
on contaminants associated with one or more of the following considerations: an available health
assessment to facilitate regulatory determinations; high public concern; critical health endpoints (for
example, a likely or suggestive carcinogen); active use (for example, pesticides); and/or an occurrence
data gap. Then EPA considered stakeholder input; looked at cost-effectiveness of analytical methods
(single methods that address multiple contaminants of interest); considered implementation factors
(such as laboratory capacity); and further considered available health data (e.g., children), occurrence
data, and persistence/mobility data.
Regulatory Determination
EPA also received many comments regarding the initiation of new drinking water regulations as a
result of the Regulatory Determination process. SDWA section 1412(b)(l)(B)(ii) directs EPA to
determine, after public notice and an opportunity to comment, whether to regulate at least five
contaminants from the CCL every five years. Prior to making regulatory determinations, EPA will
compile additional available data on all the CCL 5 contaminants to prioritize which contaminants have
sufficient information to be evaluated against the three criteria for regulation of a new drinking water
contaminant.
Under section 1412(b)(1)(A) of SDWA, EPA makes a determination to regulate a contaminant in
drinking water if the Administrator determines that:
i) the contaminant may have an adverse effect on human health;
ii) 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
iii) 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 after considering public comments on a preliminary determination, the Agency makes a final
determination to regulate a contaminant, EPA will initiate the process to propose and promulgate a
National Primary Drinking Water Regulation (NPDWR). NPDWR are legally enforceable drinking water
standards expressed as maximum contaminant levels (MCLs) or treatment technique requirements
that apply to public water systems. In that case, the statutory time frame provides for agency
proposal of a regulation within 24 months and action on a final regulation within 18 months of
proposal (with a possible extension of 9 months).
Six Year Review (SYR)
SDWA requires EPA to review each NPDWR at least once every six years and revise them, if
appropriate. Under SYR, EPA evaluates any newly available data, information and technologies to
determine if any regulatory revisions are needed to maintain or strengthen public health protection.
For EPA's third SYR, EPA concluded that eight NPDWRs are candidates for regulatory revision. EPA is
currently conducting analyses to further evaluate theses eight NPDWRs for potential regulatory
revisions under EPA's Microbial and Disinfection Byproducts (MDBP) Rule Revisions efforts.
Microbial and Disinfection Byproducts (MDBP) Rule Revisions
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Agency Discussion on Other Drinking Water Programs
Comment Excerpt from Commenter 63
The typical US resident is not equipped to comment on a draft list of contaminants that may be
subject to regulation. However, the typical US resident does rely on the FDA for protection against
harmful contaminants in our drinking water. I was struck that this is required only once every five
year and is limited to 30 contaminants and don't understand why either is in place. Beyond what is
added to the list, an explanation of the contaminants, their prevalence and coordination in mitigating
risk with local municipalities would be helpful.
Individual Response: Please see Discussion on Other Drinking Water Programs and Chemical
Technical Support Documents. The EPA regulates public drinking water (tap water) under SDWA,
while the Food and Drug Administration (FDA) regulates bottled water under the Federal Food, Drug,
and Cosmetic Act. SDWA, as established by Congress, requires EPA, once every five years, to publish a
list of no more than 30 unregulated contaminants to be monitored by public water systems, which is
known as the Unregulated Contaminant Monitoring Rule (UCMR). The UCMR is a separate action
from the CCL.
An explanation of each chemical evaluated on the Fifth Preliminary Contaminant Candidate List (PCCL
5) and the CCL 5 is provided in the Technical Support Document for the Final Fifth Contaminant
Candidate List (CCL 5) - Contaminant Information Sheets, along with the occurrence and health effects
data for those contaminants (USEPA, 2022b). Information on the microbial contaminants health risks
and occurrence can be found in the Technical Support Document for the Final Fifth Contaminant
Candidate List (CCL 5) Microbial Contaminants (USEPA, 2022c).
If it is determined that a contaminant from the Final CCL 5 warrants regulation on under SDWA, risk
mitigation would be determined as part of the rule development process to establish a NPDWR. EPA,
in partnership with states, tribes, and local municipalities, implement NPDWRs.
Comment Excerpt from Commenter 67
I support the Contaminant Candidate List (CCL) 5 Proposed Rule to regulate the "66 individual
chemicals, 12 microbes, and three chemical groups - per- and polyfluoroalkyl substances (PFAS),
cyanotoxins, and disinfection byproducts (DBPs)" (EPA 2021). If the EPA has determined that these
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EPA 815-R-22-001
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Comments Received on Other Drinking Water Programs
substances meet the criteria they set forth, then I believe the decision is sound. The criteria are as
follows:
"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 2021, II, B, 2).
The EPA should approach regulating these substances with the precautionary principle in mind. An
overabundance of caution will help to prevent potentially harmful side effects from consuming
contaminated drinking water such as cancer, infertility, organ failure, or compromising ones immune
system. If a substance has been nominated for the CCL 5, its use should be suspended from any action
that could result in its introduction to drinking water or navigable waterways or other sources of
water that are covered by the Safe Drinking Water Act (SDWA). The process of reviewing potentially
harmful substances, as mentioned, is sound, but the enforcement of the list should take greater
precedence.
All substances under review are submitted via public comment either with the scientific assumption
or knowledge that those substances could potentially cause harm to humans or the environment. The
review process is thorough and substantive in its research on the nominated substances, but the
review process is time consuming in a way that could leave compromised individuals susceptible to
harm.
My recommendation, as previously suggested, would be to generate the list of substances for review.
This includes filtering out redundant entries and substances that might not meet the criteria for
review. Once organized, the substances on the list should be suspended from use in all processes that
could result in those substances ending up in consumable drinking water. Once these substances have
been reviewed and the CCL 5 is proposed, those substances listed would become more permanently
banned and fully regulated.
In the existing process of review, the extent to which some substances affect people is estimated
using models and other predictive methods. Since not all of these substances new or old can be
consistently or safely tested on people to determine the range of symptoms, they should be
suspended from use until the entire review is conducted and a more accurate result is determined.
Individual Response: Please see Discussion on Other Drinking Water Programs. General Comments.
and Other EPA programs.
Comment Excerpt from Commenter 75
September 17, 2021
Ms. Radhika Fox,
Assistant Administrator, Office of Water
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., NW
Washington, DC 20460
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Comments Received on Other Drinking Water Programs
Subject: Proposed Rule - Drinking Water Contaminant Candidate List 5-Draft [Docket # EPA-HQ-
OW2018-0594]
Dear Ms. Fox:
In response to the notice in the Federal Register of July 19, 2021 (Volume 86, Number 135) the
Association of State Drinking Water Administrators (ASDWA) would like to offer comments on the
draft fifth Contaminant Candidate List (CCL 5). ASDWA supports and represents the collective
interests of the states, territories, and the Navajo Nation in their administration of national drinking
water program requirements within their states or territories including regulatory development and
the CCL. ASDWA appreciates the opportunity to provide the perspective of states on this important
phase of the regulatory process. It should be noted, however, that these comments do not necessarily
represent the specific views and concerns of individual states or consensus from all states. We
encourage EPA to consider individual state's comments, in addition to ASDWA's, to gain further
perspective.
The CCL Process
ASDWA strongly supports the regulatory development process outlined in the 1996 Safe Drinking
Water Act (SDWA) amendments, including the CCL, the Unregulated Contaminant Monitoring Rule
(UCMR), Regulatory Determination, and Six Year Review. Through this process, EPA can assess health
risks and assemble occurrence data needed to determine whether or not contaminants warrant
national regulations and, if so, at what levels. The regulatory determination process is designed to
capture the contaminants that pose the greatest potential public health threat, based on health
effects, occurrence and the potential regulatory opportunity for health risk reduction. This process,
supported with best available, peer-reviewed data, is vastly preferable to regulating based on
arbitrary target numbers or focusing on contaminants with high media profiles - but where there
may not be reliable data to support regulation. The CCL is the critical first step in the regulatory
consideration and development process. As such, the link between the CCL and UCMR is critical.
ASDWA is concerned with the Agency's approach for UCMR 5, specifically that the final UCMR 5 did
not include many contaminants identified in CCL 4 where national occurrence data is needed. ASDWA
recommends that EPA take steps to optimize the connection between the CCL and UCMRs. Future
UCMRs should be designed to generate robust national occurrence data to fill data gaps for
contaminants listed on the most recent CCL.
Individual Response: Please see Discussion on Other Drinking Water Programs, and General
Comments. EPA considered all public comments received on the Draft CCL 5, including comments
received from individual states. The Agency took steps to coordinate the development of the draft
CCL 5 and UCMR 5. For example, in the development of UCMR 5, EPA evaluated the contaminants
nominated by the public for potential inclusion in CCL 5 (83 FR 50364, USEPA, 2018; 86 FR 13846
USEPA, 2021c). All contaminants on the final UCMR 5 are on CCL 5. For more information on the
selection of contaminants for UCMR 5, please see the Information Compendium for Candidate
Contaminants for the Proposed Unregulated Contaminant Monitoring Rule (UCMR 5).
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Comments Received on Other Drinking Water Programs
Comment Excerpt from Commenter 75
Moving Forward with Regulatory Determinations
ASDWA recommends that EPA act on CCL contaminants with sufficient data to make a Regulatory
Determination. The CCL is not intended to be a permanent home for contaminants, yet eight
contaminants that have been on all five CCLs: Diuron, Methyl tert-butyl ether (MTBE), Vanadium,
Adenoviruses, Caliciviruses, Cyanobacteria/toxins, Helicobacter pylori, and Mycobacterium avium-
intracellular (MAC). EPA first identified these contaminants as concerning in 1998 and, from ASDWA's
perspective, no progress in regulatory-decision making has been made in over 20 years for these
eight.
Additionally, the draft CCL 5 lists 23 contaminants that have nationally representative finished water
occurrence data and qualifying health assessments. ASDWA recommends that EPA make regulatory
decisions on these contaminants in Fifth Regulatory Determination. While the law requires EPA to
make regulatory determinations for at least five contaminants from the most recent CCL within five
years after the completion of the previous round of regulatory determinations, ASDWA encourages
EPA to make a regulatory determination for any CCL contaminants with adequate data - specifically,
these 23 contaminants. Once adequate data is available to support a decision to regulate or not to
regulate, those contaminants should be removed so the focus can shift to other contaminants where
more information is needed.
Individual Response: Please see Discussion on Other Drinking Water Programs. Based on the best
available data, the eight contaminants mentioned by ASDWA as listed on previous CCLs remain
appropriate for listing on the CCL 5. The CCL process and the Regulatory Determination process
involve different statutory requirements as described in General Comments and Other Drinking Water
Programs. Contaminants that lack sufficient information for Regulatory Determination criteria will not
move forward in the regulatory determination process. For example, Diuron did not proceed from
Phase 1 to Phase 2 in the Fourth Regulatory Determination because it did not have nationally
representative finished water data and also did not have any documented occurrence in finished
water at or near levels of health concern (specifically, no documented occurrence at levels > Vz HRL).
Comment Excerpt from Commenter 87
Waterkeeper Alliance thanks you for this opportunity to comment on EPA's draft Fifth Contaminant
Candidate List (Draft CCL 5). We fully support EPA's inclusion of the robust list of dangerous
contaminants that EPA is considering for regulation under the Safe Drinking Water Act (SDWA), and
we applaud EPA's inclusion of three dangerous chemical groups (cyanotoxins, DBPs, and PFAS) rather
than listing subsets of individual chemicals. We strongly urge you to ensure that these groups of
hazardous chemicals remain on the CCL 5 when it is finalized.
We remain concerned, however, about the slow pace of EPA's administration of the SDWA over many
years with respect to review of unregulated contaminants, determining which contaminants require
listing on a CCL for further review, affirmatively determining which contaminants require regulation,
and then setting legally enforceable limits for those dangerous contaminants. We are also aware that
over the past several years EPA fell behind in meeting its statutory requirements, which resulted in
our organization and others filing a 2019 citizen suit which led to a settlement agreement pursuant to
which EPA is required to get back on track and catch up with the regulatory schedule mandated by
Congress.11 Waterkeeper Alliance, Inc., et al. v. U.S. EPA, No. 19-Civ.-899 (LJL)(S.D.N.Y.). A true and
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correct copy of this settlement agreement is available at https://waterkeeper.org/wp-
content/uploads/2020/06/
Settlement-Agreement.pdf, and is also submitted herewith as an exhibit and incorporated by
reference
herein.
In light of this history and these concerns, we urge you to do everything in your power to increase the
capacity of EPA staff assigned, and program resources allocated, to administer the SDWA, and to
dramatically enhance the agency's ability to expedite these lengthy, drawn-out, multi-year regulatory
processes. We further urge you to ensure that the precautionary principle is fully incorporated into
EPA's decision making with respect to the issuance of a Final CCL 5 and the development of final
national drinking water regulations for all of the dangerous chemicals on the draft list. Meeting the
bare minimum requirements set by Congress is simply not enough. The health of our nation, and
particularly of our children and underserved communities, depends upon EPA ensuring that the
nearly 300 million people across the United States who rely on public water systems won't
unknowingly poison themselves by drinking their tap water. There are simply too many dangerous
contaminants that remain unregulated, and when it comes to drinking water safety, what we don't
know most certainly can hurt us.
Individual Response: Please see Discussion on Other Drinking Water Programs and General
Comments. The development of final national drinking water regulations is outside the scope of the
CCL 5 process.
Comment Excerpt from Commenter 89
Overview
On behalf of the millions of members and activists of the Natural Resources Defense
Council, we submit these comments on EPA's Draft Contaminant Candidate List 5 (CCL 5), proposed at
86 Fed.Reg. 37948 (July 19, 2021). As discussed in these comments, we urge that EPA take expedited
regulatory action on PFAS (as redefined consistent with our recommendations below), unregulated
DBPs and pathogens, cyanotoxins, 1,4-dioxane, and chlorpyrifos. If the agency does not initiate
immediate regulatory steps, it should include all 66 individual chemicals and 12 microbes proposed
for the CCL 5, including the redefined PFAS class.
Individual Response: Please see Discussion on Other Drinking Water Programs, PFAS, DBPs, Draft CCL
5-Microbes, Cyanotoxins, and 1,4-Dioxane.
Comment Excerpt from Commenter 89
In sum, we recommend that EPA immediately move forward with positive regulatory determinations
for priority chemical contaminants including: (1) PFAS as a class (if the agency does not initiate an
urgent threat to health rulemaking); (2) cyanotoxins; (3) DBPs as a class (and include them in the
MDBP rulemaking); (4) 1,4-dioxane; and (5) chlorpyrifos.
Individual Response: Please see Discussion on Other Drinking Water Programs, PFAS, Cyanotoxins,
DBPs. and 1,4-Dioxane.
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Comments Received on Other Drinking Water Programs
Comment Excerpt from Commenter 89
III. EPA SHOULD INCLUDE ALL OF THE INDIVIDUAL PROPOSED
CHEMICALS & PATHOGENS IN CCL5, AND IMMEDIATELY INITIATE REGULATORY ACTION FOR KEY
CONTAMINANTS
As discussed extensively in the Federal Register notice proposing listing 66 individual chemicals and
12 microbes, and as documented in the agency's background documents and record, there is ample
evidence to justify listing all of these proposed contaminants. They are "known or anticipated to be
found in public water systems and may require regulation." [FN29: Ibid.] All may pose public health
hazards. We believe that several of these contaminants are of particularly high priority because of
their known widespread occurrence and health impacts, such as 1,4-dioxane and chlorpyrifos.
Individual Response: Please see Discussion on Other Drinking Water Programs and 1,4-Dioxane.
Comment Excerpt from Commenter 89
IV. CONCLUSION
We appreciate the opportunity to comment. We support EPA's treatment of PFAS as a class but urge
that the agency use the scientifically more soundly OECD definition rather than the overly narrow
proposed definition, The agency should immediately initiate urgent threat to health rulemaking for
the PFAS class rather than delaying by going through the CCL and complete multi-year unregulated
contaminant process that to date has not produced in a single new drinking water standard the
quarter century since 1996. We also urge that EPA consider the unregulated DBPs and microbes
proposed for the CCL for immediate controls through the upcoming MDBP rulemaking. While of
course PFAS, DBPs and the microbes all clearly qualify for the CCL5, more prompt action is required.
Similarly, with respect to cyanotoxins, we support their treatment as a class, but urge that a prompt
positive regulatory determination be made for them as well. And because of the ample database
showing the threats from 1,4-dioxane and chlorpyrifos, we urge that they too be subject to an
immediate positive regulatory determination. Clearly, all of these contaminants qualify for inclusion
on CCL5, but swifter action is needed.
Finally, with respect to all of the proposed chemical and microbial contaminants, they qualify for
inclusion on CCL5 and should be listed if EPA fails to initiate more immediate regulatory action for
them.
Individual Response: Please see Discussion on Other Drinking Water Programs, PFAS, DBPs, Draft CCL
5-Microbes, and 1,4-Dioxane.
Comment Excerpt from Commenter 96
Thank you for this opportunity to comment on EPA's draft Fifth Contaminant Candidate List (Draft
CCL5) under the Safe Drinking Water Act (SDWA). I support EPA regulating all of the dangerous
contaminants on the SDWA candidate list.
Do the right thing.
Water is Life
Individual Response: Please see Discussion on Other Drinking Water Programs.
Comment Excerpt from Commenter 97
Thank you for this opportunity to comment on EPA's draft Fifth Contaminant Candidate List (Draft
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Comments Received on Other Drinking Water Programs
CCL5) under the Safe Drinking Water Act (SDWA). I support EPA regulating all of the dangerous
contaminants on the SDWA candidate list. It is especially important that EPA include and set safe
drinking water limits on groups of extremely hazardous chemicals like cyanotoxins, disinfection
byproducts, and PFAS.
Individual Response: Please see Discussion on Other Drinking Water Programs. Cyanotoxins, DBPs,
and PFAS.
Comment Excerpt from Commenter 101
Because the public's health and safety is threatened by so many new contaminants, I am asking you
to set strict standards on the most dangerous chemicals and err on the side of protecting the public
when data is limited. The health of our nation, and particularly children and underserved
communities, depends on it.
Individual Response: Please see Discussion on Other Drinking Water Programs.
Other EPA Programs
Agency Discussion on Other EPA Programs
Agency Topic Discussion:
EPA received multiple comments related to other EPA programs including comments that Office of
Groundwater and Drinking Water (OGWDW) and Office of Research and Development (ORD) should
align efforts and that EPA should develop a stronger and more visible connection between CCL and
the Agency's research plans. Another commenter mentioned the need for CCL to inform risk
management efforts beyond the scope of the SDWA (e.g., Toxic Substance Control Act). EPA's Office
of Water coordinates its efforts with other EPA offices, including ORD and TSCA.
ORD
Office of Water's OGWDW engages with ORD throughout the CCL process, specifically obtaining input
and review of published research on current and proposed CCL chemicals and microbes. Data gaps
are identified for each CCL chemical as part of this process. EPA categorized chemical contaminants
with respect to the available occurrence, health effects and analytical methods data in the Data
Availability Assessment table (Exhibit 4), located in the Drinking Water CCL 5 - Final Federal Register
notice. EPA will continue to evaluate data needs through the regulatory determination process and
will continue to work with internal and external researchers to discuss research needs and priorities.
Additionally, ORD is currently in the next Strategic Research Action Plan (StRAP) development phase.
ORD works with other EPA Program Offices and Regions, states, and tribes to identify research gaps as
part of this process. OW provides input related to data gaps for CCL contaminants to ORD as part of
StRAP development. For the current planning cycle, research gaps include analytical methods,
occurrence/exposure, and toxicity for some CCL 5 contaminants. ORD remains flexible during research
plan implementation to adjust to changing OW priorities if they occur, enabling ORD to incorporate
CCL related research projects such as analytical methods, health effects, and treatment into ORD
research planning as needed. Existing StRAP documents for each of ORD's 6 National Research
Programs are publicly available at https://www.epa.gov/research/strategic-research-action-plans-
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Agency Discussion on Other EPA Programs
2019-2022. Once finalized the updated ORD StRAPs will be available to the public.
Toxic Substance Control Act (TSCA)
OW also coordinates with OCSPP on actions under TSCA. Under the Toxic Substances Control Act
(TSCA), as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act, EPA
evaluates potential risks from new and existing chemicals and acts to address any unreasonable risks
those chemicals present to human health and the environment. Pursuant to relevant TSCA
authorities, EPA may restrict the production, importation, processing, use, and/or disposal of specific
chemical substances in order to address unreasonable risks. For example, under TSCA section 6(a),
EPA may regulate (including restricting or banning) the manufacture, processing, distribution in
commerce, commercial use, and/or disposal of any chemical substance that EPA determined through
a risk evaluation presents an unreasonable risk of injury to human health or the environment. For
more information, see EPA's webpage on the Regulation of Chemicals under Section 6(a) of the Toxic
Substances Control Act. In addition, under TSCA section 9, EPA may coordinate certain actions on
chemical substances under TSCA with actions taken under other federal laws, including those
administered by other federal agencies as well as other laws administered by EPA. For more
information, see EPA's webpage on TSCA Section 9 Relationship to Other Federal Laws. TSCA also
gives EPA the authority to require reporting, record-keeping, and testing relating to chemical
substances and mixtures. For additional information, please visit:
https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/regulation-chemicals-under-
section-6a-toxic-substances and
https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/tsca-section-9-relationship-
other-federal-laws.
Comments Received on Other EPA Programs
Comment Excerpt from Commenter 71
AMWA encourages EPA to continue to align efforts between the Office of Ground Water and Drinking
Water (OGWDW) and the Office of Research and Development (ORD). It is vital that the work included
in ORD's multiyear strategic research action plan be in concert with the current CCL to best prioritize
research needs and utilize the agency's resources. OGWDW relies on ORD to perform the research
needed to support its mission. AMWA encourages ORD to clearly identify how it intends to support
the CCL process. Listing contaminants on the CCL should enable all offices in EPA responsible for
supporting regulatory determinations with the ability to focus precious research dollars on those
chemical and microbial contaminants that are a potential health risk to drinking water consumers.
Thank you for the opportunity to provide comments on EPA's CCL 5. If you have any questions about
these comments, please contact Stephanie Hayes Schlea, AMWA's Director of Regulatory and
Scientific Affairs, at schlea@amwa.net.
Sincerely,
Diane VanDe Hei
Chief Executive Officer
cc: Jennifer McLain, Director, Office of Ground Water and Drinking Water Eric Burneson, Director,
Standards and Risk Management Division
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Comments Received on Other EPA Programs
Individual Response: Please see Discussion on Other EPA programs.
Comment Excerpt from Commenter 75
Connecting the CCL with EPA Research
ASDWA recommends that EPA develop a stronger and more visible connection between the CCL and
the Agency's research plans. The vast amount of work to chronicle research gaps for these
contaminants listed on the CCL should serve as a springboard for federal and federally funded
research over the following five years. EPA research should aim to fill gaps in health effects data,
treatment information, and occurrence data. Contaminants listed in the CCL that do not have
approved analytical methods, for example, should be EPA's focus for analytical method development
over the next five years. If EPA already uses the CCL as the foundation for its research, ASDWA
recommends that the Agency make this connection clearer for stakeholders in the final CCL 5.
Individual Response: Please see Discussion on Other EPA Programs and Other Drinking Water
Programs. EPA has provided a table in the Final FR notice that categorizes the CCL 5 contaminants
based on the data available for each contaminant during the development of the Draft CCL 5. The CCL
is used to inform priorities for internal and external research communities.
Comment Excerpt from Commenter 77
[AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.]
Using CCL to Advance Source Water Protection
The CCL should inform risk management efforts beyond the scope of SDWA. This is especially
important for contaminants like PFAS, where the source of the contamination is beyond the
authorities of SDWA. In developing and presenting the CCL, EPA should consider how it can leverage
this information to inform discussion about chemicals that may pose a risk to the nation's drinking
water supply. For example, PFAS are a group of contaminants most appropriately addressed through
the Toxic Substances Control Act, CWA, and Resource Conservation and Recovery Act. There are
opportunities for federal agencies other than EPA to fund relevant research, employ policies and
procedures that reduce the use of PFAS substances (e.g., Department of Defense, General Services
Administration, etc.).
For other contaminants, other federal agencies may be most relevant to exposure reduction (e.g.,
Food and Drug Administration, U.S. Department of Agriculture, etc.). In order for EPA to effectively
leverage CCL 5 to reduce contaminant occurrence, the final Federal Register notice must provide a
sense of priority for (1) which contaminants appear to pose the greatest priority for action and (2)
research and data development needs to inform decision-making.
The CCL development process occurs over a five-year cycle. There are frequently stated concerns that
the SDWA regulatory process is too slow. The CCL is an opportunity for EPA to step beyond that
critique and move instead to timely initiation of action not only to inform risk in drinking water but
contamination of the nation's waters.
Individual Response: Please see Discussion on Other EPA Programs and PFAS. Actions to reduce the
occurrence of contaminants are outside the scope of the CCL process. In regard to the commenters
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Comments Received on Other EPA Programs
statement that EPA "must provide a sense of priority" for CCL, EPA has provided a table in the Final FR
notice that categorizes the CCL 5 contaminants based on the data available for each contaminant
during the development of the Draft CCL 5. As part of the Regulatory Determination process, EPA will
further prioritize CCL 5 contaminants of the greatest public health concern.
Comments Related to Process - Chemicals
Agency Discussion on Comments Related to Process - Chemicals
Agency Topic Discussion:
The CCL 5 process maintained, but improved upon, the three-step framework that was establish for
CCL 3 based on recommendation by the National Academy of Sciences' (NAS) National Research
Council and further endorsed by the National Drinking Water Advisory Council (NDWAC). The three
steps include:
(1) Building a broad universe - EPA identified and assessed a broadly defined "universe" of
potential drinking water contaminants based on occurrence and health effects data.
(2) Screening the universe to select a Preliminary CCL (PCCL) - EPA reduced the "universe" to
a preliminary CCL (PCCL) using simple screening criteria.
(3) Classifying the PCCL chemicals to select a draft CCL - Following literature searches to
collect supplemental data available for the PCCL chemicals, EPA scientist, referred to as
chemical evaluators, classified chemicals on the PCCL for listing on the draft CCL 5 based on
all of the available health effects and occurrence data for each PCCL 5 chemical.
The CCL 5 process used to select chemical contaminant has been described in detail in Technical
Support Document for the Final Fifth Contaminant Candidate List (CCL 5) - Chemical Contaminants
(USEPA, 2022a).
EPA received one comment related to CCL 5 screening process (Step 2) used to reduce the Universe to
a PCCL 5.
Comments Received Related to Process - Chemicals
Comment Excerpt from Commenter 77
If one were to focus exclusively on the 176 contaminants that were reviewed by chemical evaluators
for inclusion in the Draft CCL 5. The scoring process retained 38% of the contaminants that were
subjected to a full evaluation. Alternatively, if one were to look at the total list of provisional
contaminant candidate list (PCCL) chemicals that were listed on the Draft CCL 5 as individual
contaminants, the Draft CCL 5 chemical list would total 114 chemicals (a 44% retention rate). EPA
should consider whether the current scoring process is providing enough discrimination of high
priority contaminants or alternatively if the challenge EPA faces in refining the CCL to an actionable
length is institutional.
Individual Response: Please see Discussion on Comments Related to Process - Chemicals. Step 2 of
the CCL 5 process involves screening the Universe (~22,000 chemicals) and public nominations to a
subset of chemicals known as the preliminary CCL (PCCL), that warrant further in-depth review due to
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Comments Received Related to Process - Chemicals
their potential to occur in public water systems and pose a risk to public health.
The CCL 5 evaluation teams reviewed 214 chemicals on the PCCL and listed 66 chemicals. The
screening scores were used as a tool specifically to prioritize chemicals within the Universe and
identify a PCCL which was a subset of chemicals that required additional data gathering and
evaluation. The outcome of the screening process and screening scores were not designed to select a
CCL. The screening scores were also not meant to reflect EPA's regulatory priorities, nor reflect a
ranked list of high-priority chemicals. The screening score is a singular parameter that represents both
the relative wealth of occurrence or health data available from primary data sources and one
supplemental data source (CompTox Dashboard), and relative toxicity or occurrence for each
chemical.
As part of the classification step, EPA manually extracted additional information from supplemental
sources for PCCL chemicals, conducted in-depth reviews, and leverage the knowledge of the expert
reviewers. Because the screening score is a singular parameter that only incorporates data from
primary data sources, it is reasonable to assume and expect there will be a slight disconnect between
the screening scores and the listing decisions of the expert evaluators. The CCL process is complex;
therefore, a single parameter, screening score, cannot capture every contributing factor that
influenced listing decisions.
EPA conducted statistical tests to measure the discriminatory performance of screening scores as a
predictor of listing decisions. We found that screening scores were a moderate predictor of listing and
therefore were an appropriate tool for screening the Universe. In CCL 6, we will consider fine-tuning
the scoring rubric or adjusting the screening system to improve the screening scores' predictive
power.
Chemical Data/Data Sources
Agency Discussion on Chemical Data/Data Sources
Agency Topic Discussion:
EPA received two comments related to chemical data and data sources used in developing the CCL 5.
This included a comment supporting the agency's use of preliminary Fourth Unregulated Contaminant
Monitoring Rule (UCMR 4) data to develop the CCL 5 and the agency's "decision to no longer exclude
chemicals that could pose a public health risk through drinking water exposure from the CCL universe
solely because they lack health or occurrence data." Another comment provided recommendations
for EPA to consider with regards to using data to develop the Final CCL 5 and future CCLs, particularly
the agency's use of wastewater data as well as data collected under the Federal Insecticide,
Fungicide, and Rodenticide Act (FIFRA) and the Toxic Substances Control Act (TSCA).
The SDWA directs the agency to consider 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. In identifying these contaminants, the SDWA requires that, when
developing the CCL, EPA considers the National Contaminant Occurrence Database established under
Section 1445(g) of the SDWA. EPA must consider substances identified in Section 101(14) of the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and substances
registered as pesticides under the FIFRA as well as other relevant data sources.
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Agency Discussion on Chemical Data/Data Sources
EPA used a variety of data sources throughout the CCL 5 development process. In Step 1 of the CCL 5
process, EPA compiled health and occurrence data sources to identify chemicals that would form a
broad CCL 5 Chemical Universe. Primary data sources used to build the CCL 5 Chemical Universe met
four assessment factors: relevance, completeness, redundancy, and retrievability. These assessment
factors were developed during the CCL 3 process in response to the National Drinking Water Advisory
Council's (NDWAC) Report (2004) recommendations and are described in Section 2.2 of the Technical
Support Document for the Final Fifth Contaminant Candidate List (CCL 5) - Chemical Contaminants,
hereafter referred to as the Final CCL 5 Chemical Technical Support Document (USEPA, 2022a).
In Step 2 of the CCL 5 process, EPA applied a data-driven screening points system and screened
chemicals to a Preliminary CCL (PCCL) by evaluating the health effects and occurrence information
provided in the data sources used to compile the CCL 5 Universe. Specifically, EPA developed
screening scores for universe chemicals based on the health effects and occurrence data and
advanced the top scoring chemicals as well as publicly nominated chemicals to the PCCL for further
evaluation.
In Step 3 of the CCL 5 process, EPA conducted literature searches to identify supplemental health and
occurrence data for the PCCL chemicals. EPA summarized the data from primary and supplemental
data sources collected throughout the CCL 5 process in a standardized document called a
Contaminant Information Sheet (CIS) for each chemical. Chemical evaluators reviewed the data
provided in CISs, along with any available supplemental data and qualifying studies encountered
during the additional data collection for PCCL chemicals, to assess chemicals' potential public health
risk and make listing decision recommendations for the CCL 5.
Comments Received on Chemical Data/Data Sources
Comment Excerpt from Commenter 71
The association also greatly supports the agency's use of preliminary UCMR 4 data, as was suggested
by the SAB. This occurrence data comes directly from drinking water utilities and should be used to
inform any initiatives under the SDWA. The association agrees with EPA's assessment that it "is
important to use more recent occurrence data in the screening process to ensure that new and
potentially relevant information is not disregarded and that potentially hazardous chemicals are not
discounted."
AMWA also supports EPA's decision to no longer exclude chemicals that could pose a public health
risk through drinking water exposure from the CCL universe solely because they lack health or
occurrence data. This change to the CCL development process resulted in the compilation of the most
chemical and data-rich CCL universe to date. The association believes that the CCL process should
start by capturing all data on possible contaminants of note before moving to later steps where
qualifiers like occurrence and health effects data can be used to reduce the list to a more manageable
length for inclusion in the final CCL.
Individual Response: Please see Discussion on Chemical Data/Data Sources.
Comment Excerpt from Commenter 77
[AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.]
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Comments Received on Chemical Data/Data Sources
Lack of Information Characterizing Wastewater Discharges.
A cursory review of the information data sheets illustrates that the Agency has a limited pool of
datasets to characterize pollutant levels in wastewater discharges. The CCL 5 factsheets rely almost
exclusively on two very limited research papers. [FN5: Scott, T. M., Phillips, P. J., Kolpin, D. W., Colella,
K. M., Furlong, E. T., Foreman, W. T., & Gray, J. L. (2018). Pharmaceutical manufacturing facility
discharges can substantially increase the pharmaceutical load to US wastewaters. Science of the Total
Environment, 636, 69-79.] [FN6: Kostich MS, et al. 2014 Concentrations of prioritized pharmaceuticals
in effluents from 50 large wastewater treatment plants in the US and implications for risk estimation.
Environ Pollut. 2014 Jan;184:354-9. doi: 10.1016/j.envpol.2013.09.013. Epub 2013 Oct 3. PMID:
24095705.] Currently, permittees in the Clean Water Act (CWA) National Pollutant Discharge
Elimination System (NPDES) submit compliance monitoring data that provides discharge location,
analyte concentration, and discharge flow information. That data is submitted electronically and
should be readily available to inform the CCL process. Analytes for which monitoring is required have
specified analytical methods of known resolution and robustness. EPA's CWA analytical methods
include a number of contaminants included in the CCL 5 PCCL and it is possible that the use of this
occurrence data could inform the list of contaminants for which EPA seeks out health effects
information. [FN7: EPA, Accessed August 31, 2021. Approved CWA Chemical Test Methods.] Utilizing
data available through the CWA would be consistent with the NDWAC Report on the CCL
Classification Process and the National Research Council report that preceded the NDWAC
recommendations. [FN8: NDWAC. 2004. National Drinking Water Advisory Council Report on the CCL
Classification Process.] [FN9: NRC. 2001. Classifying Drinking Water Contaminants for Regulatory
Consideration.]
Individual Response: Please see Discussion on Chemical Data/Data Sources. EPA agrees that there is a
"limited pool of datasets to characterize pollutants levels in wastewater discharges" and that the
Clean Water Act (CWA) National Pollutant Discharge Elimination System (NPDES) compliance
monitoring data "should be readily available to inform the CCL process." EPA will consider using this
data in developing future CCLs. However, given the current CCL 5 process, EPA disagrees with the
commenter's statement that the use of this wastewater data "could inform the list of contaminants
for which EPA seeks out health effects information" for CCL 5.
To screen the Universe chemicals to a Preliminary CCL 5 (PCCL 5) and identify chemicals with the
greatest potential for public health concern, EPA developed a screening system that prioritized data
elements most relevant to drinking water exposure. Wastewater effluent data was not assigned
screening points in the CCL 5 screening system because wastewater data was considered less relevant
to drinking water exposure and less relevant than the other occurrence data elements assigned points
in the CCL 5 screening phase. EPA screened chemicals to the PCCL 5 by developing screening scores
based on the health effects and occurrence information provided in the data sources used to compile
the CCL 5 Universe. To form the PCCL 5, EPA selected the top scoring universe chemicals and publicly
nominated chemicals which were advanced for further evaluation, including conducting literature
searches to identify additional health and occurrence data.
Thirteen of the publicly nominated chemicals added to the PCCL 5 did not have available water
occurrence data, even after a targeted occurrence literature search was conducted, and therefore
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they were not included in the health effects rapid systematic review and were not evaluated by
chemical evaluators for listing on the Draft CCL 5. These chemicals were instead highlighted as having
substantial data gaps. These included 1-phenylacetone, 3-monoacetylmorphine, 6-
monoacetylmorphine, benzoic acid, benzoic acid glucuronide, hippuric acid, hydromorphone,
hydromorphone-3-glucuronide, hydroxyamphetamide, isodrin, methamphetamine, morphine-6-
glucuronide, and phenylpropanolamine. Without available data regarding measured occurrence in
water or relevant data provided by the nominators, the two evaluation teams agreed that they could
not determine whether these chemicals were likely to present the greatest public health concern
through drinking water exposure and therefore should not advance further in the CCL 5 process.
Searching for wastewater data was not part of the occurrence literature search protocol which was
targeted towards identifying finished and ambient water data. If identifying wastewater data had
been part of the occurrence literature search protocol, and wastewater data on these 13 chemicals
had been identified through NPDES or other sources, then it is possible that the use of this occurrence
data could have informed the list of contaminants for which EPA sought out health effects
information as the commenter stated. EPA may consider including wastewater data in the targeted
occurrence literature search for future CCLs. The data elements used for point assignments in the CCL
5 screening system and the occurrence literature search protocol are provided in Table 4 and
Appendix E, respectively, of the Final CCL 5 Chemical Technical Support Document (USEPA, 2022a).
Comment Excerpt from Commenter 77
[In reviewing the CCL 5 process as described by the Agency, AWWA found:]
3. In constructing the CCL Universe, EPA combined the health effects data from multiple forms
of some chemical contaminants. [FN22: EPA. 2021. Technical Support Document for the Draft Fifth
Contaminant Candidate List (CCL 5) Chemical Contaminants. EPA 815-R-21-005.] This approach is
described in the docket, and there are compounds for which this would be a sound approach.
Unfortunately, the Draft CCL 5 documentation only provides a handful of examples. The docket does
not summarize the list of CCL or PCCL chemicals for which this approach was influenced by the
availability of data. Consequently, the public does not have a clear notion of which contaminants are,
in fact, included in the CCL based on data regarding the health-effects posed by contaminants likely to
be present in water.
Individual Response: Please see discussion on Chemical Technical Support Document. The
commenter describes that "In constructing the CCL Universe, EPA combined the health effects data
from multiple forms of some chemical contaminants." It is unclear what the commenter is referring
to; however, in this response, EPA assumes the commenter is referring to the grouping of several
chemicals, such as lithium and lithium salts, under a single Distributed Structure-Searchable Toxicity
Database Substance Identifier (DTXSID). For additional examples of chemicals grouped under a single
DTXSID, please see Section 2.4.2 of the Final CCL 5 Chemical Technical Support Document (USEPA,
2022a). The commenter is correct that the "Draft CCL 5 documentation only provides a handful of
examples." EPA's efforts to group DTXSIDs in this way focused on identifying chemicals with ionized
and/or salt forms (e.g., inorganic ions). EPA recognizes that communication of this approach has not
been clear and is considering ways to make it more transparent in future CCLs.
EPA has updated the Contaminant Information Sheets (CISs) for five contaminants to clarify which
data entries are associated with other forms of the contaminant; these include cypermethrin, lithium,
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manganese, propiconazole, and vanadium (please see Technical Support Document for the Final Fifth
Contaminant List (CCL 5) - Contaminant Information Sheets, hereafter referred to as the Final CCL 5
CIS Technical Support Document (USEPA, 2022b).
Comment Excerpt from Commenter 77
[In reviewing the CCL 5 process as described by the Agency, AWWA found:]
4. EPA describes, in limited detail, a new presumption of contaminant occurrence used during CCL 5
screening. [FN23: EPA. 2021. Technical Support Document for the Draft Fifth Contaminant Candidate
List (CCL 5) Chemical Contaminants. EPA 815-R-21-005.] Specifically, EPA occurrence metrics were
calculated where non-detects were set equal to one-half the method detection level when data
sources provided a method detection level (MDL). EPA does not describe how this presumption
impacts the composition of the CCL 5 list in comparison with alternative valid approaches (e.g.,
setting non-detects equal to "0" or the MDL). Occurrence is a critical data element in the CCL
development process. No doubt EPA analyzed such a substantial change on CCL contaminant scores.
While this assumption of occurrence should generally be avoided for analyses such as construction of
the CCL, by failing to show its work the Agency prevents commenters from understanding how
influential this assumption is in the CCL 5 process. EPA makes similar assumptions elsewhere (e.g.,
chemical production data). Taken individually such assumptions can be influential; when applied
regularly to multiple data elements, the compounding conservatism can distort the occurrence data
elements that underpin the CCL process.
Individual Response: Please see Discussion on Chemical Data/Data Sources. EPA acknowledges the
commenter's concern of how EPA calculated certain occurrence metrics for CCL 5 screening. In this
response, EPA assumes the comment specifically refers to how EPA imputed or temporarily
substituted the following occurrence metrics in the screening step of CCL 5: 1) maximum
concentrations values for non-detected chemicals in finished or ambient waters when the study or
survey provided detection limits, and 2) chemical production volume categories for determining point
assignments.
EPA's decision to substitute a maximum concentration value for non-detected chemicals in ambient
and finished waters and chemical production values at the CCL 5 screening step is a conservative and
health-protective approach. In CCL 5 classification, chemical concentrations in water were based on
analytical detections only and production volumes were the same values as reported by the Chemical
Data Reporting (CDR) rule.
EPA disagrees with the commenter that substituting concentration values for non-detected chemicals
in finished and ambient waters in CCL screening should be avoided. Non-detections do not necessarily
indicate that the chemical is absent, and risk of exposure is zero, but rather indicate that the amount
of chemical present is below a level that could be detected or quantified. There is potential risk for
exposure when a chemical is reported as a non-detect; therefore, imputing maximum concentrations
for chemicals in ambient and finished waters where the study or survey provides detection limit
information is a health-protective approach. EPA did not test out alternative approaches for imputing
or substituting these occurrence metrics in the screening step for CCL 5. Therefore, EPA did not assess
the impact that these presumptions had on the screening scores or the composition of the CCL 5.
A chemical's maximum concentration in finished water is a data element used to derive a chemical's
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screening Hazard Quotient (sHQ). The sHQ is the ratio of the maximum concentration of the chemical
in finished drinking water to the most health-protective health screening level for a chemical. The
sHQ is the highest tiered occurrence data element in the scoring rubric in CCL 5 screening and most
applicable to potential hazards through drinking water. The sHQ requires a chemical to have a
maximum concentration in finished water value in order to be calculated. If the maximum
concentrations in finished water were not imputed for non-detected chemicals where the study or
survey provided detection limit information and relied solely on analytical detections, the sHQ could
not be calculated for those chemicals. Non-detections in finished water do not mean the
concentration of the chemical is zero. Therefore, not imputing maximum concentration in finished
water for non-detected chemicals may have resulted in an underestimation of potential drinking
water exposure at the screening step.
Production volume data required special data processing steps to be incorporated into the CCL 5
screening rubric. Chemical production volumes were reported as categories (i.e., a range of values
such as 100,000 - 500,000 lb.) or inequalities (e.g., < 25,000 lb.) and needed to be converted to single
numerical values so that distributions and quantiles could be calculated. These quantiles were
subsequently used to establish relative point assignments for the production volume data element.
EPA's method of converting production volumes to single numerical values was driven by how the
data was originally reported by CDR. EPA analyzed the variations of production volume categories and
determined that using the minimum value for the category ranges and temporarily substituting Vz for
the lowest production volume was the appropriate approach.
The lowest two production volume categories available for chemicals in the CCL 5 Universe were "<
25000 lb" (e.g. less than 25,000 lb.) and "25000 -100000 lb" (e.g. between 25,000 lb. and 100,000
lb.). EPA determined that these two production volumes should not be assigned the same numerical
value (25,000 lb.) because CDR reports the production volumes as two distinct categories. Therefore,
EPA temporarily substituted "12,500 lb" for "<25000 lb" and used the minimum values for the other
production volume categories for point assignments.
Similarly, the highest two production volume categories available for chemicals in the CCL 5 Universe
were "> 200,000,000,000 lb" (e.g. greater than 200 billion lb.) and "190,000,000,000-
200,000,000,000 lb" (e.g. between 190 billion lb. and 200 billion lb.). EPA determined that these two
production volume categories should not be assigned the same numerical value (200 billion lb.)
because CDR reports the production volumes as two distinct categories. Therefore, EPA substituted
"190,000,000,000 lb" for the "190,000,000,000 - 200,000,000,000 lb" category and "200,000,000,000
lb" to the "> 200,000,000,000 lb" category specifically for calculating quantiles and relative point
assignments.
Additionally, the statistical ranges, the differences between the largest and smallest values, of
production volume categories were not equal. Therefore, EPA determined that using the average
value of production volume categories was inappropriate for establishing relative point assignments
in CCL 5 screening.
EPA agrees with the commenter that contaminant occurrence is a critical element of the CCL
development process. EPA agrees with the commentor that the action of imputing or substituting
occurrence metric values individually and when applied regularly to multiple occurrence metrics can
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be influential to the CCL process. EPA may consider alternative approaches for imputing or
substituting these occurrence metrics and assess cumulative impact these assumptions have on the
CCL process in future rounds of CCL.
Comment Excerpt from Commenter 77
[In reviewing the CCL 5 process as described by the Agency, AWWA found:]
6. EPA notes the use of FIFRA modelled pesticide concentrations to estimate exposure
in developing the Draft CCL 5. The FIFRA drinking water exposure models are deliberately
conservative, which generate exposure estimates that are typically substantially higher than observed
occurrence. The chemical information sheets for three Draft CCL 5 contaminants (i.e., Bensulide,
Propanil, and Thiamethoxam) include the modelled estimates. It is not clear from the docket how
influential the FIFRA pesticide modelling estimates are as part of the CCL 5 decision-making process.
FIFRA risk assessments did not emphasize drinking water risks for Propanil or Thiamethoxam.
7. The Draft CCL 5 is inconsistent in its treatment of pesticide degradates. CCL 5 considered risk
analysis of individual pesticides conducted under the Federal Insecticide Fungicide Rodenticide Act.
CCL 5 Contaminant Information Sheets reference at least 12 FIFRA re-registration dockets that note
the role of pesticide degradates including degradates created during drinking water treatment in
estimating associated risks. Yet, the Draft CCL 5 includes four triazine degradates without explanation
of why these four degradates warrant specific inclusion and the degradates of other pesticides in the
Draft CCL 5 do not. The relative accessibility of information from available sources is not a rational
explanation for this inconsistency given the extensive referencing of FIFRA work products in the Draft
CCL 5 Federal Register notice docket.
Individual Response: Please see Discussion on Chemical Data/Data Sources and the Final CCL 5
Chemical Technical Support Document. EPA's Office of Pesticide Programs (OPP) risk assessments
were an important supplemental source of health and occurrence data for the CCL 5. EPA agrees with
the commenter that modeled estimates from the OPP risk assessments may overestimate actual
environmental concentrations as they are often based on maximum use and application rates; the
chemical evaluators were made aware of this when they were presented the data to evaluate
contaminants for listing on the CCL 5.
The commenter stated that "It is not clear from the docket how influential the FIFRA pesticide
modelling estimates are as part of the CCL 5 decision-making process." As explained in Section 4.2.1.2
of the Final CCL 5 Chemical Technical Support Document (USEPA, 2022a), EPA manually extracted
modeled concentration data, known as estimated environmental concentrations (EECs) or estimated
drinking water concentrations (EDWCs), from OPP risk assessments only for pesticides on the PCCL 5
that lacked nationally representative finished and/or nationally representative ambient water data.
As shown in the protocol in Appendix H of the Final CCL 5 Chemical Technical Support Document, EPA
prioritized the use of nationally representative finished water data to derive the final hazard quotient
(fHQ) for chemicals, followed by nationally representative ambient water data. EPA used modeled
water data developed by OPP only when no measured nationally representative water data was
available for calculating the fHQ. The fHQ is a calculated data element intended to indicate a
chemical's potential for public health risk related to exposure from drinking water by capturing the
relationship between a chemical's relative potency and the concentrations at which it may be found
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in water. The fHQ is one of many data elements that inform the CCL 5 listing process. Chemical
evaluators reviewed all relevant health effects and occurrence data provided on the CISs and any
available supplemental data and qualifying studies encountered during the additional data collection
for PCCL chemicals in order to provide listing decision recommendations for the CCL 5. For an idea of
how influential different variables may be during the listing decision process, please see Section
4.6.3.1 of the Final CCL 5 Chemical Technical Support Document (USEPA, 2022a) which provides the
results of the simple logistic regression model EPA conducted.
In particular, the commenter noted that the "FIFRA risk assessments did not emphasize drinking
water risks for Propanil or Thiamethoxam." Fourteen pesticides on the PCCL 5 lacked nationally
representative finished and/or nationally representative ambient water data and 3 of these pesticides
were included on the CCL 5: Bensulide, Propanil, and Thiamethoxam. For these pesticides, the EECs
were used to calculate the fHQ which was only one data point that chemical evaluators considered
when making listing decisions. For example, regarding Propanil and Thiamethoxam, the OPP risk
assessments were also provided to the chemical evaluators to review as part of the evaluation
process. EPA acknowledges that these two pesticides have a data gap; however, based on a review of
all of the data provided on the CISs and the risk assessments, EPA is listing these two pesticides on the
CCL 5.
EPA disagrees with the commenter's statement that the "Draft CCL 5 is inconsistent in its treatment
of pesticide degradates." In particular, the commenter expressed confusion with the inclusion of four
triazine degradates on the Draft CCL 5 while other pesticide degradates in "FIFRA re-registration
dockets" were not included. Pesticide degradates went through the CCL 5 process the same way as
every other chemical contaminant, passing through three steps: Building the Chemical Universe,
Screening Chemicals to a PCCL, and Classification of PCCL Chemicals to Select the CCL. At the end of
this process, contaminants found to be known or anticipated to occur in public water systems and not
subject to proposed or promulgated NPDWRs were listed on the CCL 5. If a pesticide registered with
FIFRA or pesticide degradate was not listed on the CCL 5, this means it either did not have enough
screening points to be included in the PCCL 5 and was not further evaluated for listing, or the
chemical evaluators did not recommend it for listing on the CCL 5 based on the evaluated data. All
evaluated data are provided in the Final CCL 5 CIS Technical Support Document.
Comment Excerpt from Commenter 77
[In reviewing the CCL 5 process as described by the Agency, AWWA found:]
9. There are more than 1,300 pesticide constituents regulated under FIFRA and 86,000
chemicals in the TSCA inventory. The Draft CCL 5 includes 39 pesticides and 5 pesticide degradates.
Pesticide-related contaminants make up over half of the individually named chemical contaminants in
the Draft CCL. FIFRA maintains an active and thorough registration / re-registration process providing
data in public-facing documents that do not exist for the thousands of industrial chemicals managed
under TSCA. Both FIFRA and TSCA regulated chemicals are in the CCL 5 Universe. It is not clear from
the docket whether the Draft CCL 5 process is being biased by the data-rich and transparent
implementation of FIFRA re-registration practice. It appears that the FIFRA program is more capable
of informing the CCL 5 process compared to the much less transparent TSCA process. In finalizing CCL
5, EPA should evaluate the impact of data accessibility and completeness between these two
programs and for their potential to influence the CCL process. Such an analysis could inform not only
EPA's SDWA processes but those implemented under TSCA.
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10. The FIFRA program evaluations of pesticide chemistry, actual use, and conservative modelling
of use patterns indicate that aggregate dietary exposure including drinking water exposure is unlikely
to reach a level of concern for roughly half of the pesticides listed in the Draft CCL 5. For several
pesticides, drinking water exposure was a significant, if not dominant, route of exposure in FIFRA
exposure assessments, but only in a few instances were levels of concern exceeded under modelled
high-risk pesticide use conditions. Even after review of FIFRA dockets (updated since the end of data
collection for the Draft CCL docket), it is not apparent how EPA is reconciling inclusion of all listed
pesticides in the Draft CCL 5 with available information from FIFRA. In finalizing Draft CCL 5 EPA
should clearly describe how this evaluation, which is largely reliant on the same data as available to
the FIFRA pesticide re-registration, is reaching different conclusions regarding the potential risk to
drinking water and why this is appropriate.
Individual Response: Please see Discussion on Chemical Data/Data Sources. The commenter noted
that "Pesticide-related contaminants make up over half of the individually named chemical
contaminants in the Draft CCL" and expressed concern about the greater accessibility of FIFRA data
compared to TSCA data and how this may bias what contaminants are listed on the Draft CCL 5. SDWA
section 1412(b)(l)(B)(i), as amended in 1996, specifies that the unregulated contaminants considered
for listing on CCL shall include, among others, substances registered as pesticides under FIFRA. For
this reason, FIFRA registered pesticide and pesticide ingredients represent a significant source of
chemicals for consideration in CCL. With regards to data collected under TSCA, EPA used production
volume information collected by EPA under the Chemical Data Reporting (CDR) rule requirements
pursuant to section 8 of TSCA as a primary data source to build the CCL 5 Universe of chemicals. Data
collected under TSCA also served as a source of supplemental data in the CCL 5 development process;
if available, EPA extracted health data from the agency's Risk Evaluations conducted under TSCA to
derive health concentrations for chemicals evaluated for listing on the CCL 5. Some TSCA data
includes confidential business information (CBI) and therefore was not included in the CCL 5 process.
EPA notes that primary data sources used to build the CCL 5 Chemical Universe must meet four
assessment factors: relevance, completeness, redundancy, and retrievability (see Section 2.2 of Final
CCL 5 Chemical Technical Support Document (USEPA, 2022a)). To be retrievable, the data must be
formatted for automated retrieval (e.g., data are stored tabular format) and publicly accessible. These
assessment factors were developed during the CCL 3 process in response to the National Drinking
Water Advisory Council's (NDWAC) 2004 recommendations. For more information on the FIFRA and
TSCA programs, please see Discussion on Other EPA Programs.
The commenter stated that "FIFRA program evaluations [...] indicate that aggregate dietary exposure
including drinking water exposure is unlikely to reach a level of concern for roughly half of the
pesticides listed in the Draft CCL 5." EPA notes that OPP risk assessments are one of many sources of
data evaluated during the CCL 5 listing decision process. Chemical evaluators reviewed all relevant
health effects and occurrence data provided on the CISs and any available supplemental data and
qualifying studies encountered during the additional data collection for PCCL chemicals in order to
provide listing decision recommendations for the CCL 5. All of the data that informed the evaluation
process is provided in the Final CCL 5 CIS Technical Support Document. EPA disagrees with the
commenter's statement that the Draft CCL 5 evaluation "is reaching different conclusions regarding
the potential risk to drinking water" than the FIFRA pesticide assessments. OPP assessment and the
CCL are two different processes. Under the SDWA, the CCL is a list of contaminants not subject to any
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proposed or promulgated NPDWR which are known or anticipated to occur in public water systems
and may require regulation under SDWA. EPA's approach to the CCL utilizes the best available data to
characterize the occurrence and adverse health risks a chemical may pose from potential drinking
water exposure. Based on all of the available data and the SDWA requirements for listing, EPA
identified the CCL 5.
Additionally, EPA manually extracted modeled concentration data from OPP risk assessments for
pesticides on the PCCL 5 that lacked nationally representative finished and/or nationally
representative ambient water data. While EPA did not manually extract the conclusions, the full risk
assessments were provided to the chemical evaluators to review as part of the evaluation process.
These data were not in a retrievable format that could be efficiently extracted for all CCL 5 Chemical
Universe pesticides; however, EPA will consider manually extracting the modeled concentration data
and conclusions from the risk assessments for all pesticides evaluated during the classification step
and including them on CISs in future CCLs.
Regarding the commenter's concern about the transparency of the TSCA process, that is outside the
scope of the CCL; please see Discussion on Other EPA Programs.
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Contaminant Groups
Agency Discussion on Contaminant Groups
Agency Topic Discussion:
EPA received many comments related to the inclusion of contaminant groups on the CCL 5. The CCL 5
includes three contaminant groups: cyanotoxins, disinfection byproducts (DBPs), and per- and
polyfluoroalkyl substances (PFAS). Many commenters expressed support for listing these three groups
on the CCL 5, while many were opposed or expressed concerns with the ways the groups were
defined. Please see Discussions on Cyanotoxins, DBPs. and PFAS for responses to comments on these
particular groups.
Multiple commenters expressed support for EPA considering contaminants as groups in the CCL
process or listing contaminant groups on the CCL. However, a couple commenters raised concerns
about the way EPA applied this grouping approach to certain contaminants while listing some other
contaminants, such as pesticides with a similar mode of action, individually. As described in Section
4.7 of the Final CCL 5 Chemical Technical Support Document (USEPA, 2022a), PFAS, cyanotoxins, and
DBPs are chemical groups that have been identified as agency priorities and contaminants of concern
for drinking water under other agency actions, including the 2021 PFAS Strategic Roadmap, the 2015
Algal Toxin Risk Assessment and Management Strategic Plan for Drinking Water, and EPA's decision
identifying a number of microbial and disinfection byproducts (MDBPs) drinking water regulations as
candidates for revision in the Six-Year Review 3 (SYR 3) of NPDWRs. As a couple of commenters
pointed out, some of the pesticides evaluated for the CCL 5, such as pyrethroids and
organophosphates, share a common mechanism and are grouped under other agency actions
including the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). While EPA evaluated and
listed contaminants in these groups individually, the agency provided chemical evaluators with the
Office of Pesticide Programs (OPP) cumulative risk assessments for these groups to consider when
evaluating these contaminants for listing on the CCL 5. EPA may consider listing these and other
contaminants as groups in future CCLs.
A couple of commenters requested more information on how EPA plans to prioritize contaminants
within the groups on the CCL 5 (cyanotoxins, DBPs, PFAS), specifically related to EPA's research
priorities. For information on research priorities, please see Discussion on Other EPA Programs. One
commenter inquired about how groups of contaminants will be treated for Regulatory
Determinations and UCMR selection. As stated in Section 4.7 of the Final CCL 5 Chemical Technical
Support Document, listing contaminant groups on the CCL 5 does not necessarily mean EPA will make
subsequent regulatory decisions for the entire group. EPA will evaluate scientific data on the listed
groups, subgroups, and individual contaminants to inform any regulatory determinations for the
group, subgroup, or individual contaminants in the group. For more information on Regulatory
Determination and UCMR, please see Discussion on Other Drinking Water Programs.
Comments Received on Contaminant Groups
Comment Excerpt from Commenter 55
I'm concerned about the data here being misleading, particularly where functional groups are
assessed separately or where data are under-represented due to isomerism.
First, to address functional groups: one group that comes up often in the PCCL but not frequently in
the Draft CCL are pyrethroids. In this category, only permethrin was listed on the draft CCL. Some of
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the others on the PCCL include: cypermethrin, cyfluthrin, bifenthrin, cyhalothrin, fenpropathrin,
lambda-cyhalothrin, and tefluthrin. There seems to be plenty of data across the board between these
pyrethroids, but it doesn't seem like the health effects data are compared. Given that they are
functional analogs and would have similar modes of action, I would encourage these to be considered
jointly or more serious consideration given to the fact that many of these will have similar modes of
action.
Individual Response: Please see Discussion on Contaminant Groups.
Comment Excerpt from Commenter 64
EPA's Contaminant Candidate List 5 (CCL 5) will have a significant impact on drinking water regulation.
EPA is tasked with implementing the Safe Drinking Water Act. As such, long-term regulatory planning
can empower EPA to make a positive contribution in building safe and healthy communities.
The draft CCL5 lists 66 unique chemicals, twelve individual microbes, and three groups of chemicals
(namely, polyfluoroalkyl substances (PFAS), disinfection byproducts (DBPs), and cyanotoxins). I
recommend PFAS be listed as a group, or class, in the final CCL5, rather than retaining only PFOA and
PFOS, which were listed in the Final CCL4. Adopting precautionary approach in environmental
regulation is essential in ensuring ecosystem and human health and safety. For too long new or poorly
understood chemicals were released into our water and soil with minimal or no regulation. In the
case of PFAS, communities have been, and will continue to be for generations, paying the price for
that lack of regulation in absorbing the costs of cancer, high infant and child mortality rates, and other
disastrous health outcomes.
Past CCLs have generally focused on listing unique substances, instead of groups. By restricting
regulation to just a handful of chemicals in an overall harmful class, EPA limits its effectiveness in
administering the SWDA. For example, the Association of Safe Drinking Water Agencies shared in its
response to the draft CCL5 that PFHxS, GenX, and PFBA (unique chemicals in the PFAS group) "will not
necessarily be removed by treatment installed for PFOA and PFOS." Regulating individual substances
in a group is akin to playing the classic game "Whack-A-Mole," where the player, using a mallet,
attempts to hit mechanical moles that pop up out of a grid of holes at random. As the game
continues, ever more moles pop up ever faster, and the player almost always loses eventually.
Because there are thousands of known unique chemicals in the PFAS group, and more may be found
or created as time goes on, the EPA will eventually lose its game of Whack-A-Mole, with deadly
consequences for communities. In contrast, by regulating PFAS as a class, water quality agencies can
more holistically address water contamination caused by these substances.
There is precedent for listing a group of chemicals. One notable example, cyanotoxins, comes from
2016's final CCL4 (83 FR 81099). Cyanotoxins are most well-known for contributing to algal blooms
and hypoxia in bodies of water, as well as harming humans and animals. Listing groups of
contaminants permits EPA and lower-level regulatory agencies flexibility in managing their water
quality programs, while also reducing the burden of regulation. I commend EPA for its commitment to
"working collaboratively with states, tribes, water systems, and local communities that have been
impacted by PFAS," as stated in an EPA press release dated February 22, 2021. By including PFAS as a
group, rather than focusing on individual chemicals, EPA can make good on its commitment to
support affected communities. Moreover, by investing in drinking water safety - a critical component
in public infrastructure - EPA can support the current Presidential administration's objectives, thereby
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not only earning a modicum of political clout but also positioning itself to make immense positive
changes in U.S. communities.
Individual Response: Please see Discussion on Contaminant Groups. Other Drinking Water Programs.
and PFAS. EPA agrees with the commenter's recommendation for "PFAS be listed as a group, or class,
in the final CCL5, rather than retaining only PFOA and PFOS, which were listed in the Final CCL4."
Including the broad group of PFAS on the CCL 5 is responsive to the many public nominations EPA
received and the agency's commitment to better understand and ultimately reduce the potential risks
caused by this broad class of chemicals. EPA notes that PFOA and PFOS are not considered under CCL
5 as the agency made final regulatory determinations to regulate these two chemicals. 3.1 PFAS The
commenter notes the importance of "Adopting a precautionary approach in environmental
regulation" and recommends "regulating PFAS as a class." EPA notes that regulation is outside of the
scope of the CCL 5.
Comment Excerpt from Commenter 71
AMWA appreciates EPA's clarification that including a set of substances as a group, such as per- and
polyfluoroalkyl substances (PFAS), cyanotoxins, and disinfection byproducts, does not necessarily
mean it will be moved further through the SDWA process as a group. AMWA believes this is
appropriate but asks EPA to include more information as to how the agency plans to prioritize
substances within these groups, specifically related to EPA's research priorities.
Individual Response: Please see Discussion on Contaminant Groups and Other EPA Programs.
Comment Excerpt from Commenter 75
Contaminant Groups
ASDWA generally supports EPA's use of groups on the CCL, however, the agency should provide
clarification on how groups of contaminants will be treated for Regulatory Determinations and UCMR
selection as well as how contaminants within the groups will be prioritized for research.
Individual Response: Please see Discussion on Contaminant Groups. Other Drinking Water Programs.
and Other EPA Programs.
Comment Excerpt from Commenter 77
Organizing the CCL so that it clearly communicates the strength of available information and the
Agency's concern based on that data would also clarify inclusion of contaminants as part of a group in
the CCL. The Draft CCL 5 also includes groups of contaminants for which there is a wide variety of
available information with respect to individual chemicals in the group (e.g., levels of toxicity,
occurrence (or a risk of occurrence)). For example, the Draft CCL 5 includes more than 1,350 per- and
polyfluoroalkyl substances (PFAS) and notes that listing all PFAS individually would be both "difficult
and challenging." Rather than choosing between the extremes (e.g., listing all PFAS as a group or
listing 1,000's of PFAS) the Agency could reflect groups of PFAS compounds based on the relevant and
applicable data at hand. This approach is not dissimilar to the implied prioritization of certain groups
of DBPs in the Draft CCL 5 Federal Register notice, though the docket underlying the notice regarding
DBPs is lacking. [FN4: 4 86 FR 37954]
Individual Response: Please see Discussion on Contaminant Groups. PFAS. and DBPs. The commenter
states that "Organizing the CCL so that it clearly communicates the strength of available information
and the Agency's concern based on that data would also clarify inclusion of contaminants as part of a
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group in the CCL." EPA notes that the contaminants included on the CCL 5 as part of a group have
been identified as agency priorities and contaminants of concern for drinking water under other EPA
actions. The CCL is not intended to be organized in a way to communicate the "strength of available
information;" the CCL is a list of contaminants, not currently subject to any proposed or promulgated
NPDWR that are known or anticipated to occur in public water systems and may require regulation
under SDWA. For information on the available information for CCL 5 contaminants, EPA recommends
the commenter view the Contaminant Information Sheets (CISs) which display health effects,
occurrence, and other data on CCL 5 contaminants (see Final CCL 5 CIS Technical Support Document
(USEPA, 2022b)). In addition, EPA has provided a table summarizing the data availability for CCL 5
chemicals (please see Chapter 5 of the Final CCL 5 Chemical Technical Support Document (USEPA,
2022a)).
Comment Excerpt from Commenter 77
[In reviewing the CCL 5 process as described by the Agency, AWWA found:]
8. The Draft CCL 5 includes three groups of contaminants (i.e., cyanotoxins, disinfection
byproducts, and per- and polyfluoroalkyl substances). These groups contain contaminants that do not
share known common mechanisms of toxicity and are known to occur in water under different
conditions and timescales. Conversely, the Draft CCL 5 includes groups of pesticides that are already
managed under FIFRA because such similarities exist, yet the docket does not address what
distinguishes one "group" from another in the CCL decision-making process (i.e., why are some
contaminants listed as individuals and others in groups). The description of EPA's area-under-the-
curve receiver operating characteristics model is the only point in the docket that the Agency notes
that orthophosphate pesticides (OPs) are highly selected by the Draft CCL 5 process when 12 of the
Draft CCL contaminants are OPs. [FN25: EPA. 2021. Technical Support Document for the Draft Fifth
Contaminant Candidate List (CCL 5) Chemical Contaminants. EPA 815-R-21-005.]
Individual Response: Please see Discussion on Contaminant Groups and Pesticides. The commenter
stated that "The description of EPA's area-under-the-curve receiver operating characteristics model is
the only point in the docket that the Agency notes that orthophosphate pesticides (OPs) are highly
selected by the Draft CCL 5 process." In this response, EPA assumes the commenter is referring to
organophosphates. As described in Section 4.6.3 of the Final CCL 5 Chemical Technical Support
Document (USEPA, 2022a), the chemical evaluators evaluated 19 organophosphates. Of these 19,
they recommended 14 for listing on the Draft CCL 5. To explore what factors may have influenced
listing decisions for the CCL 5, EPA conducted post-evaluation statistical analyses. This included the
use of an area under the curve-receiver operating characteristics (AUC-ROC) curve to assess how well
various models predict listing decisions. EPA does not state that organophosphates are "highly
selected by the Draft CCL 5 process;" however, according to one of the models assessed by the AUC-
ROC curve, chemical evaluators were more likely to recommend for listing on the Draft CCL 5 those
PCCL 5 chemicals they evaluated that had high prevalence, screening scores, or fHQs (deciles), or that
were organophosphates. Please see Section 4.6.3 of the Final CCL 5 Chemical Technical Support
Document for more information. Such post-evaluation analyses help to identify what variables may
be associated with positive listing decisions and could be used to inform how the agency addresses
groups in future CCLs.
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Cyanotoxins
Agency Discussion on Cyanotoxins
Agency Topic Discussion:
Cyanobacteria, formerly referred to as blue-green algae, are found naturally in lakes, rivers, ponds
and other surface waters. When certain conditions exist, such as in warm water containing an
abundance of nutrients, they can rapidly form harmful algal blooms (HABs). Some HABs are capable
of producing toxins, called cyanotoxins, which can pose health risks to humans and animals through
drinking water and recreational water exposure.
Conventional water treatment can generally remove intact cyanobacterial cells and low levels of
cyanotoxins from source waters. However, water systems may face challenges and/or increased costs
in providing cyanotoxin-free drinking water during a severe bloom event when there are high levels of
cyanobacteria and cyanotoxins in source waters. The prevalence, duration and frequency of HABs in
freshwater is expanding in the U.S. and HABs continue to present a challenge for many state drinking
water programs. For this reason, cyanotoxins remain an agency priority as stated in EPA's Algal Toxin
Risk Assessment and Management Strategic Plan for Drinking Water (USEPA, 2015). Cyanotoxins are
one of the three chemical groups EPA listed as a group instead of individually on CCL 5. The group of
cyanotoxins on CCL 5 includes, but is not limited to: Anatoxin-a, cylindrospermopsin, microcystins,
and saxitoxin.
As information is available, EPA will evaluate scientific data on the listed groups, subgroups, and/or
individual contaminants included in the group to inform any regulatory determinations for the group,
subgroup, or individual contaminants in the group.
Comments Received on Cyanotoxins
Comment Excerpt from Commenter 64
There is precedent for listing a group of chemicals. One notable example, cyanotoxins, comes from
2016's final CCL4 (83 FR 81099). Cyanotoxins are most well-known for contributing to algal blooms
and hypoxia in bodies of water, as well as harming humans and animals. Listing groups of
contaminants permits EPA and lower-level regulatory agencies flexibility in managing their water
quality programs, while also reducing the burden of regulation.
Individual Response: Please see Discussion on Cyanotoxins.
Comment Excerpt from Commenter 75
ASDWA supports the inclusion of cyanotoxins on CCL 5, as cyanotoxins from harmful algal blooms
(HABs) are occurring with increasing frequency in drinking water sources and negatively impacting
drinking water treatment facilities throughout the US. State drinking water programs play a key role
in helping water systems monitor for and treat cyanotoxins and respond to HAB events. Multiple
states have been adversely affected by cyanotoxins, including those along the Ohio River, in Toledo,
Ohio and in Salem, Oregon where the water systems had to issue "do not drink" notices to their
customers. These drinking water treatment facilities face a difficult task of not only addressing water
quality changes from HABs and removing cyanotoxins but doing so in a safe and cost-effective way to
protect public health.
Many states have taken action to address cyanotoxins, such as Oregon and Ohio, who have developed
state regulations for cyanotoxin monitoring. Oregon requires that drinking water systems using
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surface water sources susceptible to harmful algae blooms routinely test for Total Microcystins and
Cylindrospermopsin and notify the public about the test results. Ohio has also developed HAB
monitoring and reporting rule requirements for public water systems with a surface water source.
Additionally, Wisconsin, Indiana, Massachusetts, New York, Oregon, and Ohio have developed algae
websites that provide information, fact sheets, and resources for the public about possible high levels
of blue-green algae and the potential health effects of cyanotoxins.
Individual Response: Please see Discussion on Cyanotoxins. EPA agrees that cyanotoxins remain a
public health concern for many state drinking water programs.
Comment Excerpt from Commenter 77
Cyanotoxins
Cyanotoxins are a group of toxins naturally produced and released by some specifies of
cyanobacteria. Several cyanotoxins were listed on the Third and Fourth CCL as part of a group. AWWA
has recommended their inclusion in both the CCL and as part of the Unregulated Contaminant
Monitoring Rule sampling. UCMR 4 included several Microcystins: nodularin, cylindrospermopsin, and
anatoxin-a. As EPA summarizes, the UCMR is a nationally representative dataset providing sufficient
data to support rulemaking decisions. In EPA's most recent data summary from UCMR 4 (July 2021)
microcystins were only detected in finished water sample points at 0.2% of all participating systems
and cylindrospermopsin was only detected in less than 0.4% of participating systems. Despite the
extremely low occurrence of these cyanotoxins, the Draft CCL 5 includes these contaminants.
The role of CCL is to identify priority contaminants for potential drinking water regulation.
Contaminants listed in the CCL should represent contaminants that present a public health risk and an
opportunity for effective risk-reduction based on a chemical's occurrence and toxicity and its removal
through drinking water treatment. Given that several cyanotoxins (e.g., total microcystins and
cylindrospermopsin) were generally not detected in drinking water as part of the UCMR 4 monitoring
program, it is unclear why these contaminants are included in the Draft CCL 5. The substantiation
provided by the Agency in the docket to-date, is that inclusion is consistent with a risk assessment
and plan created in 2015 that has not been subsequently updated. [FN41: EPA. 2015. Algal Toxin Risk
Assessment and Management Strategic Plan for Drinking Water.] [FN42: EPA. 2021. Technical Support
Document for the Draft Fifth Contaminant Candidate List (CCL 5) Chemical Contaminants. EPA815-R-
21-005.] If retained in the Final CCL 5 Federal Register notice, EPA must provide additional
information to demonstrate the value and objectives in retaining the several cyanotoxins for which
EPA has occurrence data from UCMR 4. At present, EPA summarizes its bases for inclusion of the
cyanotoxins as:
1. Not based on an assessment of data availability for individual cyanotoxin occurrence or health
effects data
2. Reflecting model cyanotoxin health effects and the presumption that all cyanotoxins will have
similar effects
3. Based on an assumption that since some cyanotoxins are present, occurrence of all in the group are
likely and present at a level of concern [FN43: 86 FR 37970]
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The UCMR 4 data should give EPA pause, and the Agency should reconsider whether its assumptions
regarding inclusion of this group are sound. If retained in the Final CCL 5, EPA should more clearly
articulate a rationale for the cyanotoxins included.
Conclusion
AWWA greatly appreciates the Agency's efforts to bring the best available information to bear on
identifying contaminants of concern in drinking water. The staff involved in developing the Draft CCL 5
should be commended.
EPA is often criticized for not regulating drinking water contaminants quickly. Managing the CCL as an
ongoing component of the Agency's SDWA program rather than a cyclical statutory duty and aligning
research and communication priorities, based on prioritized needs tied to the CCL, would be an
important step toward addressing such critics. A more focused and prioritized CCL would great
improve the Agency's success in advancing a clear and consistent regulatory agenda, which would
benefit public health, the Agency's day-to -day work, and the sector more broadly.
Individual Response: Please see Discussion on Cyanotoxins. General Comments, and Other Drinking
Water Programs. Under UCMR 4, public water systems monitored for 10 cyanotoxins during a 4-
consecutive month period from March 2018 through November 2020. At the time when the Draft CCL
5 was published, the UCMR 4 data set was not finalized. The final UCMR 4 data set was published on
February 18, 2022. The next step would be for EPA to consider the cyanotoxins as part of the
regulatory determinations process. The full UCMR 4 data set will be considered as part of that
process. Cyanotoxins continue to be listed on CCL 5 as an aggregate group in order to encompass all
toxins produced by cyanobacteria. Not all cyanotoxins were monitored as part of UCMR 4 and
significant health effects data is not available for many cyanotoxins. Significant information gaps still
exist on the health impacts and/or occurrence for many cyanotoxins (e.g., euglenophycin and
saxitoxins). Therefore, cyanotoxins still pose a potential public health risk and EPA retained listing
cyanotoxins as a group on CCL 5.
Comment Excerpt from Commenter 89
We also support listing cyanotoxins as a group instead of listing them as individual chemicals.
Individual Response: Please see Discussion on Cyanotoxins.
Comment Excerpt from Commenter 89
EPA SHOULD ADDRESS CYANOTOXINS AND DBPs AS CLASSES
As discussed extensively in EPA's CCL5 proposal and the record and background documents, the class
of cyanotoxins (including but not limited to anatoxin-a, cylindrospermopsin, microcystins, and
saxitoxin) are widespread, often found in complex mixtures, known or anticipated to occur in public
water systems and pose substantial public health threats. They clearly meet the criteria under the
Safe Drinking Water Act (SDWA) for listing [FN28: See SDWA §1412(b)(l)(B)(i)(l).] as well as for a
positive regulatory determination.
Individual Response: Please see Discussion on Cyanotoxins and Other Drinking Water Programs.
EPA agrees that cyanotoxins are appropriate to be included on CCL 5 as a group. However, an
evaluation as part of the regulatory determination process is necessary to determine whether EPA
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will consider regulatory action. The regulatory determination process is outside the scope of CCL
process. A contaminant must be evaluated under the regulatory determination process to determine
whether EPA will make a positive regulatory determination and initiate regulatory action.
Disinfection Byproducts (DBPs)
Agency Discussion on Disinfection Byproducts (DBPs)
Agency Topic Discussion:
Disinfection Byproducts (DBPs) are formed when disinfectants react with naturally occurring organic
materials in water. EPA is listing 23 unregulated DBPs as a group on the CCL 5, along with cyanotoxins
and PFAS, which all having been identified as agency priorities and contaminants of concern for
drinking water under other EPA actions. The group of 23 unregulated DBPs listed for CCL 5 were
either publicly nominated, or among the 250 top-scoring chemicals included on the PCCL 5. EPA
acknowledges there are differences in occurrence and health effects information among DBPs in the
group. The CCL is not intended to be organized in a way to communicate the "strength of available
information;" the CCL is a list of contaminants, not currently subject to any proposed or promulgated
NPDWR that are known or anticipated to occur in public water systems and may require regulation
under SDWA. The 23 unregulated DBPs listed on CCL 5 can be found in Table 25 in the Final CCL 5
Chemical Technical Support Document (USEPA, 2022a).
Under the Stage 2 Disinfectants and Disinfection Byproducts Rule, there are currently 11 regulated
DBPs from three subgroups that include four trihalomethanes, five haloacetic acids, and two
inorganic compounds (bromate and chlorite). Under the third Six-Year Review (SYR 3), EPA identified
eight National Primary Drinking Water Regulations (NPDWRs) covered by the Microbial and
Disinfection Byproducts (MDBP) rules as "candidates for revision" (USEPA, 2017).
Currently, EPA is conducting analyses to further evaluate the candidates for potential regulatory
revisions identified under SYR 3 known as the Microbial Disinfection Byproducts (MDBP) Rule
Revisions. Additionally, under the MDBP rule revisions effort, EPA is also evaluating information on
unregulated DBPs.
Comments Received on DBPs
Comment Excerpt from Commenter 62
B) HAA6br: Brominated Haloacetic Acids, particularly Bromochloracetic acids (BCAA) which are added
to the drinking water supply to purify it against contaminants. Most water supplies abide by the first 5
regulated halo acetic acids (HAA5), but leave out BCAA, as it is it not necessary to detect it. BCAA
causes abnormalities in laboratory animals and is quite commonly found in drinking water. Some
harmful effects include: sore throat, vomiting and diarrhea
[FN20: Delaware Health and Social Services. Division of Public Health. "Haloacetic Acids".
https://dhss.delaware.gov/dhss/dph/files/haloaceacfaq.pdf1
Individual Response: Please see Discussion on DBPs. Disinfection byproducts are formed when an
oxidant, like chlorine or chloramine, disinfectants, are added to water and interact with organic
matter. Bromochloroacetic acid is not added to drinking water but may form in drinking water when
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bromide is present. EPA agrees with the commenter that brominated haloacetic acids are of concern
and therefore EPA listed brominated haloacetic acids as one of the 23 DBPs listed as a group on the
CCL 5. The reference that the commenter has provided will be taken into consideration.
Comment Excerpt from Commenter 75
The following comments provide additional detail on contaminants listed on the Draft CCL 5 that are a
particular concern for state drinking water programs.
Unregulated Disinfection Byproducts (DBPs)
ASDWA supports the continued inclusion of unregulated DBPs on CCL 5. According to EPA research,
"Since 1976, more than 600 DBPs have been reported, but only a few of them have been
quantitatively assessed for their occurrence and health effects." States are concerned about the lack
of information for many DBPs. As EPA considers changes to the Microbial and DBP regulations, health
effects data and additional data on the accuracy and reliability of analytical methods for detecting
unregulated DBPs at low concentrations is critical. ASDWA recommends that EPA work to fill research
gaps for these contaminants, particularly the nine species of haloacetic acids (HAA9), nitrosamines,
brominated and iodinated DBPs. This research effort should also include developing further
information, including treatment, on precursors (e.g., bromide) for these currently unregulated
contaminants and the means to protect sources of drinking water.
Individual Response: Please see Discussion on DBPs. EPA agrees that unregulated DBPs are a public
health concern and recognizes the information gaps and needs for additional research.
Comment Excerpt from Commenter 77
[In reviewing the CCL 5 process as described by the Agency, AWWA found:]
2. With the ongoing M/DBP effort, it is not clear why EPA was not able to include information on the
health effects and occurrence of DBPs in the Draft CCL 5 Federal Register notice support documents.
EPA must have information not otherwise included in the support documents to justify selecting 23
DBPs from the hundreds of known DBPs. At present, EPA cites the inclusion of 23 DBPs in the CCL 5
solely on the basis that it is contemplating revising existing M/DBP regulations. [FN21: EPA. 2021.
Technical Support Document for the Draft Fifth Contaminant Candidate List (CCL 5) Chemical
Contaminants. EPA 815-R-21-005.] In finalizing CCL 5, EPA should present the supporting data for
including DBPs as a group in the CCL, since EPA is aware that there are marked differences in both
DBP occurrence and health effects. AWWA agrees with EPA's stated intent of evaluating DBPs in a
cohesive manner while assuring adequate disinfection.
Individual Response: Please see Discussion on DBPs and Other Drinking Water Programs. The MDBP
rule revisions effort is outside the scope of CCL 5.
Comment Excerpt from Commenter 85
September 17, 2021
Via Regulations.gov
U.S. Environmental Protection Agency
EPA Docket Center, Water Docket
Environmental Protection Agency
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Mail Code: 28221T
1200 Pennsylvania Ave, NW.
Washington, DC 20460
ATTN: Kesha Forrest
Office Ground Water and Drinking Water
Standards and Risk Management Division
Re: EPA-HQ-OW-2018-0594
Dear Ms. Forrest:
The Chloropicrin Manufacturers' Task Force (CMTF) [FN1: The CMTF represents all U.S.
manufacturing-use registrants and many end-use registrants of chloropicrin.] appreciates the
opportunity to comment on the draft Drinking Water Contaminant Candidate List 5 (CCL 5). The
CMTF's comments specifically address the proposal to include chloropicrin on the CCL 5. Chloropicrin
has been proposed for the list as part of 23 unregulated Disinfection Byproducts (DBP). [FN2: 86 Fed.
Reg. 37,948 (July 19, 2021). In addition, chloropicrin was publicly nominated as a DBP. Id. at 37,968.
Chloropicrin is also a registered pesticide; however, EPA's Office of Pesticide Programs concluded as
part of the Re-Registration of chloropicrin that "the Agency does not expect the pesticidal uses of
chloropicrin to adversely impact ground water or surface water." EPA Memo re Chloropicrin Third
Revision of the HED Human Health Risk Assessment, p. 76 (April 30, 2009) (hereinafter EPA 2009).]
However, as explained below chloropicrin does not meet the Safe Drinking Water Act (SDWA) criteria
for listing.
Halogenated organic compounds like chloropicrin can form during the chlorination process of natural
water containing nitrates and dissolved organic substances. The use of ozone in the water treatment
process followed by chlorination may increase the amount of chloropicrin in the water. [FN3: EPA
Memo re Chloropicrin Final Revised HED Human Health Risk Assessment for the Reregistration of
Chloropicrin, p. 73 (June 18, 2008) (hereinafter EPA 2008); see also, EPA 2009, p. 19.] Reported
concentrations of chloropicrin in the treated water were less than 1.00 ng/L. [FN4: EPA 2008, p. 73.]
EPA's Office of Pesticide Programs concluded that "the concentrations of chloropicrin detected in
potable water are below the concentrations of HED's level of concern." [FN5: Id.]
EPA must consider three statutory criteria when identifying contaminants for potential regulation: (1)
the contaminant may have an adverse effect on the health of persons; (2) the contaminant is known
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, (3) the regulation of the contaminant presents
a meaningful opportunity for health risk reduction for persons served by public water systems. [FN6:
42 U.S.C. §300g-l(b)(l)(A).]
As explained above, there is not a substantial likelihood that chloropicrin will occur at levels of public
health concern. Regulation of the contaminant does not present a meaningful opportunity for health
risk reduction for persons served by public water systems. Therefore, the criteria for listing are not
met.
If you have any questions, please contact the Task Force's manager, Sara Beth Watson at 202-429-
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6460 or swatson@steptoe.com.
Regards,
Stephen Wilhelm
Chairman
Chloropicrin Manufacturers' Task Force
cc: Sara Beth Watson
Individual Response: Please see Discussion on DBPs. General Comments, and Other Drinking Water
Programs. EPA disagrees with the comment that chloropicrin "does not meet the Safe Drinking Water
Act (SDWA) criteria for listing". The SDWA requirements for listing a contaminant on the CCL are that
it is unregulated, known or anticipated to occur in public water systems, and may require regulation
under SDWA. The three criteria that the commenter references are the criteria for the regulatory
determinations process and are required for determining whether a CCL contaminant may require
regulation under SDWA. The regulatory determinations process is a separate process from the CCL
listing process.
Comment Excerpt from Commenter 89
With respect to the 23 unregulated disinfection byproducts EPA has proposed, we urge that they be
considered as part of the upcoming MDBP regulations, which we have under separate cover (with
AWWA, AMWA and CWA) urged be conducted through a regulatory negotiation. These DBPs also
clearly qualify as a class for inclusion in the CCL5.
Individual Response: Please see Discussion on DBPs and Other Drinking Water Programs.
EPA agrees that DBPs are appropriate to be added to CCL 5 as a group. EPA's MDBP rule revisions are
outside the scope of CCL 5.
Comment Excerpt from Commenter 89
[II. EPA SHOULD ADDRESS CYANOTOXINS AND DBPs AS CLASSES]
Similarly, the 23 unregulated disinfection byproducts EPA has listed in the proposal (four haloacetic
acids, two haloacetonitriles, three halonitromethanes, six iodinated trihalomethanes, six
nitrosamines, chlorate and formaldehyde) are known or anticipated to be of substantial health
concern and to widely occur in drinking water. They also should be considered as a class under the
upcoming MDBP rulemaking, and EPA clearly can and should make a positive regulatory
determination for them. Moreover, it is manifest that they qualify for inclusion in the CCL 5 as a class
for the reasons noted in the Federal Register notice for the proposal, supporting documents cited
therein, and in the record.
Individual Response: Please see Discussion on DBPs. Cvanotoxins. and Other Drinking Water
Programs. EPA agrees that DBPs are appropriate to be added to CCL 5 as a group. EPA's MDBP rule
revisions and the regulatory determination process are outside the scope of CCL 5.
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Comment Excerpt from Commenter 89
With respect to the 23 unregulated disinfection byproducts EPA has proposed, we urge that they be
considered as part of the upcoming MDBP regulations, which we have under separate cover (with
AWWA, AMWA and CWA) urged be conducted through a regulatory negotiation.
Individual Response: Please see Discussion on DBPs and Other Drinking Water Programs.
EPA's MDBP rule revisions and the regulatory determination process are outside the scope of CCL 5.
Per- and PolyfluoroaIkyI substances (PFAS)
Agency Discussion on Per- and Polyfluoroalkyl substances (PFAS)
Agency Topic Discussion:
PFAS are a class of synthetic chemicals that are most commonly used to make products resistant to
water, heat, and stains and are consequently found in industrial and consumer products like clothing,
food packaging, cookware, cosmetics, carpeting, and fire-fighting foam. PFAS have been detected in
water (finished and source water), air, fish, and soil at locations across the nation. These widely used
and persistent chemicals have also been found in blood samples of humans (CDC, 2019). EPA is
committed to addressing per- and polyfluoroalkyl substances (PFAS) in drinking water and the
environment in general. In October 2021, EPA announced a comprehensive PFAS Strategic Roadmap
which outlined an integrated approach for tackling PFAS challenges in the environment (USEPA,
2021b). This strategic roadmap lays out EPA's whole-of-agency approach to addressing PFAS. The
strategic roadmap builds on and accelerates implementation of policy actions identified in the
Agency's 2019 action plan and commits to bolder new policies to safeguard public health, protect the
environment, and hold polluters accountable.
EPA's integrated approach to PFAS is focused on three central directives:
• Research. Invest in research, development, and innovation to increase understanding of PFAS
exposures and toxicities, human health and ecological effects, and effective interventions that
incorporate the best available science.
• Restrict. Pursue a comprehensive approach to proactively prevent PFAS from entering air, land, and
water at levels that can adversely impact human health and the environment.
• Remediate. Broaden and accelerate the cleanup of PFAS contamination to protect human health
and ecological systems.
EPA's approach is shaped by the unique challenges to addressing PFAS contamination. EPA cannot
solve the problem of "forever chemicals" by tackling one route of exposure or one use at a time. EPA
will continue to pursue a rigorous scientific agenda to better characterize toxicities, understand
exposure pathways, and identify new methods to avert and remediate PFAS pollution. As EPA learns
more about the family of PFAS chemicals, the Agency can do more to protect public health and the
environment.
In regard to addressing PFAS in drinking water, the roadmap specifically lays out its plans to
undertake national PFAS monitoring under UCMR 5 and establish drinking water regulations for PFOA
and PFOS. The roadmap also states that as part of the PFOA and PFOS regulation, EPA will also
evaluate additional PFAS and consider regulatory actions to address groups of PFAS. Including PFAS as
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Agency Discussion on Per- and Polyfluoroalkyl substances (PFAS)
a group on the CCL 5, aligns with EPA's commitment to better understand PFAS and ultimately reduce
the potential risk caused by this broad class of chemicals.
When initiating the CCL 5 process, EPA sought public nominations for unregulated contaminants to be
considered for inclusion on the CCL 5. EPA compiled and reviewed the information from the
nominations process to assist in identifying contaminants for listing. Among the chemicals nominated,
PFAS chemicals received the most nominations. Listing a group of PFAS on CCL 5 is also responsive to
public nominations which stated that EPA should "include PFAS chemicals as a class on CCL 5."
For the Draft CCL 5, EPA proposed to list PFAS as a group inclusive of any PFAS (except for PFOA and
PFOS). For the purposes of the Draft CCL 5, the structural definition of PFAS included per- and
polyfluorinated substances that structurally contain the unit R-(CF2)-C(F)(R')R". Both the CF2 and CF
moieties are saturated carbons and none of the R groups (R, R' or R") can be hydrogen.
Listing PFAS as a group
EPA received many comments supporting EPA's decision to list PFAS as a group while multiple
commenters opposed listing PFAS as a group. EPA agrees with commenters that support listing PFAS
as a group and has retained a group of PFAS on the Final CCL 5, with the exception for PFOA and PFOS
in which EPA has made final positive regulatory determinations under the fourth Regulatory
Determinations process and is in the process of developing a National Primary Drinking Water
Regulation. EPA maintains its decision that the CCL 5 PFAS group meets the criteria for listing, which is
that they are not yet subject to drinking water regulation, are known or "anticipated" to occur in
drinking water systems and may require drinking water regulation. EPA will evaluate scientific data on
the listed groups, subgroups, and individual contaminants included in the group to inform any
regulatory determinations for the group, subgroup, or individual contaminants in the group.
PFAS definition
EPA received many comments related to expanding the Draft CCL 5 PFAS structural definition because
it was too narrow and did not include PFAS that have been identified in drinking water and source
water. Commenters also provided alternative PFAS definitions for EPA's consideration and these
alternatives have been addressed in the "Individual Responses" below. EPA agrees with the
commenters who recommended expanding the CCL 5 PFAS definition and in response, EPA is
expanding the CCL 5 PFAS structural definition to state the following:
For the purpose of CCL 5, the structural definition of per- and polyfluoroalkyl substances
(PFAS) includes chemicals that contain at least one of these three structures (except for PFOA
and PFOS which are already in the regulatory process):
1) R-(CF2)-CF(R')R", where both the CF2 and CF moieties are saturated carbons, and
none of the R groups can be hydrogen
2) R-CF20CF2-R', where both the CF2 moieties are saturated carbons, and none of the R
groups can be hydrogen
3) CF3C(CF3)RR', where all the carbons are saturated, and none of the R groups can be
hydrogen.
This revised definition maintains the Draft CCL 5 structural definition but augments it to include
additional PFAS substructures to address PFAS known to occur in drinking water and/or source water.
Many of these were mentioned in the public comments, such as Perfluoro-2-methoxyacetic acid
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Agency Discussion on Per- and Polyfluoroalkyl substances (PFAS)
(PFMOAA) and Perfluoro-2-methoxy propanoic acid (PMPA). This revised definition is only for the
purposes of CCL 5. It is not meant to represent an Agency-wide definition. The definition could be
revised for future cycles as more information is gathered on PFAS. EPA is also including additional
language in the Final CCL 5 FRN acknowledging emerging PFAS contaminants that EPA may consider
moving directly to the regulatory determination process or consider listing those contaminants for
future CCLs. The FRN also references EPA's Comptox Database which includes a CCL 5 PFAS list of over
10,000 PFAS substances that meet the Final CCL 5 PFAS definition.
Several public commenters suggested EPA apply the Organisation for Economic Co-operation and
Development (OECD) 2021 PFAS definition for CCL 5. The OECD definition states as follows:
"PFASs are defined as fluorinated substances that contain at least one fully fluorinated methyl
or methylene carbon atom (without any H/CI/Br/l atom attached to it), i.e., with a few noted
exceptions, any chemical with at least a perfluorinated methyl group (-CF3) or a
perfluorinated methylene group (-CF2-) is a PFAS."
OECD acknowledges that this definition is expansive and describes the universe of chemicals with
perfluorinated carbons, and that "working scope" definitions may be needed depending on
programmatic needs. EPA is committed to addressing PFAS known to occur in drinking water and/or
source water but the OECD 2021 definition would also include fluorinated chemicals that are unlikely
to be found in source water based on chemical characteristics.
PFAS contamination in drinking water/environment
EPA also received many comments regarding the regulation of PFAS substances and their associated
risk on the environment, especially in drinking water/environment. The regulation of PFAS substances
and their associated risk on the environment is outside the scope of CCL 5. Please see Discussion on
Other Drinking Water Programs and Other EPA Programs.
PFAS testing methods
EPA also received many comments regarding PFAS analytical testing methods. EPA has developed,
validated, and published three methods to support the analysis of 29 PFAS in drinking water: Method
533 (2019), 537 (2009) and 537.1 (2020). EPA's methods were developed and validated for the
analysis of finished drinking water (i.e., potable water) from both groundwater and surface water
sources. Multiple commenters suggested or recommended that EPA limit the CCL 5 PFAS group to the
29 PFAS included on UCMR 5 with validated drinking water analytical methods. EPA disagrees with
these suggests/recommendations. SDWA does not require validated drinking water analytical
methods for a contaminant to be included on the CCL. EPA is continuing to develop testing methods
to understand occurrence to support future regulatory decisions.
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EPA 815-R-22-001
October 2022
Comments Received on PFAS
Comment Excerpt from Commenter 56
Polyfluoroalkyl substances (PFAS) should be added to the fifth drinking water Contaminant Candidate
List (CCL 5). Millions of public citizens have expressed their concern with PFAS and the associated risk
imposed on safe drinking water. Therefore, regulating potentially toxic substances such as PFAS under
the SDWA should be a top priority for the EPA on CCL 5.
PFAS are manufactured and used in a variety of industries around the world which has led to
extensive studies on these types of chemicals. PFAS can be found in many things such as food
packaging materials, commercial household products, or within workplace production facility
equipment. In regard to CCL 5, PFAS in drinking water are typically found in a localized areas such as a
landfill or wastewater treatment center but also have the ability to build up over time in living
organisms (EPA 2021). PFAS do not easily breakdown and there is evidence that these chemicals can
accumulate overtime leading to adverse human health effects.
More than 3,000 synthetic compounds are classified as PFAS and if these chemicals are not regulated
properly, they will continue to accumulate in drinking water as well as the environment. Numerous
studies indicate that PFAS can have detrimental effects on the endocrine system in humans, including
the thyroid function in particular (Coperchini 2021). According to the US National Library of Medicine,
PFAS have been recognized as endocrine disrupters through in vitro studies and also on different
types of subjects, including animal and human data. This is important because thyroid hormones are
involved in many different biological processes including regulation of energy expenditure,
neurodevelopment, growth, synaptogenesis, and metabolic processes well into adult life (Coperchini
2021). Recent reviews of thyroid disrupting effects on various biological pathways show that any step
in the biosynthesis and secretion of thyroid hormones could be affected by PFAS exposure. These
effects include impairment of iodine uptake by thyroid cells, interference in thyroglobulin synthesis,
modification of Thyrperoxidase, and interference with feedback mechanisms (Coperchini 2021).
Thyroid disease is not the only concern associated with PFAS exposure. Recently, studies have also
linked the possible relationship between PFAS exposure and thyroid dysfunction during pregnancy
(Coperchini 2021). Elevated levels of thyroid-stimulating hormone (TSH) in early pregnancy is also
associated with possible adverse maternal and fetal outcomes. From available morbidity studies, it is
evident that PFAS definitely alters human thyroid hormone production and could potentially
contribute to thyroid autoimmunity (Fenton 2020).
Current data indicates that 90% of US residents have detectable PFAS levels in their bloodstreams and
there are many common PFAS associated with drinking water (Chowdhury 2020). Within those
detectable levels of PFAS are long chain compounds that tend to be more resistant to degradation
and decay, often persisting for 2-9 years within the human body. Table 1 below shows half-life
estimates of various PFAS substances in rats, mice, monkeys, and humans (Fenton 2020).
Given that many epidemiological studies have extensively explored the relationship between PFAS
exposure and potential human toxicity, PFAS should be nominated as a known contaminant within
public water systems on the CCL 5 list. Granted, the adverse health effects within humans are
dependent on an array of factors including magnitude, duration, and route of exposure to PFAS
chemicals. It is important to note which studies provide the strongest evidence across different
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October 2022
Comments Received on PFAS
populations. It is evident that preliminary data from heavily exposed PFAS populations is also
correlated to reproductive and development issues, kidney disease, kidney cancer, lipid and insulin
dysregulation, liver disease and cancer, immune dysfunction, hepatic and metabolic toxicity (Fenton
2020).
Individual Response: Please see Discussion on PFAS. General Comments, and Other Drinking Water
Program.
Comment Excerpt from Commenter 69
I have a question about your definition of PFAS in the CCL 5 proposed rule: "... includes per- and
polyfluorinated substances that structurally contain the unit R-(CF2)-C(F)(R')R". Both the CF2 and CF
moieties are saturated carbons and none of the R groups (R, R' or R") can be hydrogen (USEPA,
2021f)." I'm particularly confused by the term "C(F)(R')R" and also just "R" and wondering what are
some compounds that some people consider PFAS that may not be included. For example, some
definitions of PFAS include anything with a fully fluorinated C atom (a single C2 or C3). It looks like this
definition wouldn't include all these but I can't tell for sure.
Jason Lowery
Madison, Wl
Individual Response: Please see Discussion on PFAS. Perfluoroalkyl substances are fully fluorinated
(perfluoro-) alkane (carbon-chain) molecules. Their basic chemical structure is a chain of two or more
carbon atoms (or the tail) with a charged functional group (the head) attached at one end. The
functional groups commonly are carboxylates or sulfonates, but other forms are also detected in the
environment. For perfluoroalkyl substances, fluorine atoms are attached to all possible bonding sites
along the carbon chain of the tail, except for one bonding site on the last carbon where the functional
group head is attached. "CnF2n+l" defines the length of the perfluoroalkyl chain tail, "n" is >2, and
"R" represents the attached functional group head. Note that the functional group may contain 1 or
more carbon atoms, which are included in the total number of carbons when naming the compound.
Comment Excerpt from Commenter 70
National Ground Water Association Comments on:
Environmental Protection Agency Drinking Water
Contaminant Candidate List 5-Draft
ACTION: Notice of availability; request for comments; Proposed Rule by the Environmental Protection
Agency for Drinking Water Contaminant Candidate List 5
Publication Date: July 19, 2021
Document Citation: 86 FR 37948
Docket ID Number: EPA-HQ-OW-2018-0594
SUMMARY:
The U.S. Environmental Protection Agency (EPA) is publishing a draft list of contaminants that are
currently not subject to any proposed or promulgated national primary drinking water regulations for
public review and comment. These contaminants are known or anticipated to occur in public water
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October 2022
Comments Received on PFAS
systems and may require regulation under the Safe Drinking Water Act (SDWA). This draft list is the
Fifth Contaminant Candidate List (CCL 5) published by the agency since the SDWA amendments of
1996. The Draft CCL 5 includes 66 chemicals, 3 chemical groups (16 per- and polyfluoroalkyl
substances (PFAS), cyanotoxins, and disinfection byproducts) and 12 microbial contaminants. EPA
seeks comment on the Draft CCL 5 and on improvements implemented in the CCL 5 process for
consideration in developing future CCLs.
Electronic Link: https://www.federalregister.gov/documents/2021/07/19/202115121/drinking-water-
contaminant-candidate-list-5-draft
Submission Due Date: September 17, 2021.
Date Submitted: September 7, 2021
COMMENTS OF THE NATIONAL GROUND WATER ASSOCIATION (NGWA) TO EPA
The NGWA supports the inclusion on the Contaminant Candidate List 5 (CCL 5) of the 16 per- and
polyfluoroalkyl substances (PFAS) listed in the footnote below. [FN1: Perfluoro(2-((6-
chlorohexyl)oxy)ethanesulfonic acid) (9CI-PF30NS), Perfluoro-2-methyl-3-oxahexanoic acid,
Perfluorobutane sulfonic acid (PFBS), Perfluorobutyric acid (PFBA), Perfluorodecanoic acid
(PFDeA/PFDA), Perfluorododecanoic acid (PFDoA), Perfluoroheptanoic acid (PFHpA), Perfluorohexane
sulfonic acid (PFHxS), Perfluorohexanoic acid (PFHxA), Perfluoronononanoic acid (PFNA),
Perfluorooctanesulfonamide (PFOSA), Perfluorooctane sulfonic acid (PFOS), Perfluorooctanoic acid
(PFOA), Perfluorotetradecanoic acid (PFTA), Perfluorotridecanoic acid (PFTrDA), Perfluoroundecanoic
acid (PFUA/PFUnA).]
The NGWA commented on and supported the establishment of the previous list of the Unregulated
Contaminant Monitoring Rule 5 (UCMR5) monitoring program to establish the occurrence of the 29
PFAS among representative large and small water systems in order to determine exposure of the U.S.
population to these chemical substances (publication date: March 11, 2021; document citation: 86 FR
13846; Agency/Docket Number EPA-HQ-OW-2018-0530).
NGWA has focused on concerns about PFAS prior to and since its report:
National Ground Water Association (NGWA). 2017 (and Updates). Groundwater and PFAS: State of
Knowledge and Practice. NGWA Press, Westerville, Ohio.
This report documented treatment capability for PFOA and PFOS and cited concerns for other PFAS in
groundwater.
In the letter to EPA of June 3, 2020, joined by NGWA and eight other prominent water associations,
the associations asked that EPA (1) engage with outside experts to develop and review a public health
risk assessment for PFAS, (2) with all key stakeholders establish the adequacy of analytical methods
and capacity, effective risk communication, and sustainable treatment options, among other
important factors, (3) accelerate research on water treatment, occurrence, and health effects to
support future decision making and contaminant prioritization, and (4) leverage available regulatory
tools in other statutes to gather occurrence and health risk assessment data and organize them to
support research and decision making, using regulatory tools that include the Toxics Release
Inventory, Sections 4 and 8 of the Toxic Substances Control Act, and the Unregulated Contaminant
Monitoring Rule.
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Comments Received on PFAS
NGWA appreciates EPA moving forward on regulating PFAS in drinking water with this action
regarding CCL 5. The EPA PFAS program should be a comprehensive approach to protecting our
nation's population from these chemicals in the future. NGWA also notes the following factors related
to the need for regulating and monitoring of PFAS across the country:
The Centers for Disease Control and Prevention reports that PFAS chemicals are in the blood of
virtually all Americans. [FN2: Centers for Disease Control and Prevention. 2017. Per- and
Polyfluorinated Substances (PFAS) Factsheet.
https://www.cdc.gov/biomonitoring/PFAS FactSheet.html ] Seventy-seven (77) percent (401 out of
524) of military installations across the nation have measured levels of PFAS contamination. The
Environmental Working Group (EWG) found that 90 more current and former Army and Army
National Guard installations had levels of ground or drinking water contamination than previously
reported. [FN3: Military.com. 2019. List of Bases Contaminated with PFAS Chemicals Expected to
Grow, Pentagon Says, https://www.military.com/dailv-news/2019/09/13/list-bases-contaminated-
pfas-chemicals-expectedgrowpentagon-says.html ]
NGWA is very concerned that Guelfo and Adamson (2018) [FN4: Guelfo, J.L. and D.T. Adamson. 2018.
Evaluation of a national data set for insights into sources, composition, and concentrations of per-
and polyfluoroalkyl substances (PFASs) in U.S. drinking water. Environmental Pollution vol. 236 (May),
pp.505-513. Cited in U.S. Environmental Protection Agency, Regulatory Determination 4 Support
Document; EPA 815-R-19-006, December 2019, p. 3-38.] examined PFAS results from UCMR 3 in detail
and found that approximately 50 percent of samples with reportable levels of one or more PFAS
detections contained at least two PFAS and 72 percent of detections occurred in groundwater. When
detected, median total PFAS concentrations were higher in small PWSs serving 10,000 or fewer
persons (0.12 ng/L) than in large PWSs (0.053 ng/L). This PFAS level in small water systems is nearly
twice the current Health Reference Level of 70 ppt. This concern is highlighted by the fact that 75
percent (36,398) of all community water systems are primarily ground-supplied, and 96 percent of
those groundwater-supplied systems are small water systems serving 10,000 or fewer people and
have fewer resources to manage their water systems. Ninety-seven (97) percent (93,807) of
nontransient and transient noncommunity water systems are groundwater-supplied. [FN5: U.S.
Environmental Protection Agency. 2021. Drinking Water Government Performance Reporting Act
Tool.
https://obipublic.epa.gov/analvtics/saw.dllPPortalPages&PortalPath=/shared/SFDW/ portal/Public ]
Guelfo and Adamson also reported that large water systems serving more than 10,000 persons were
5.6 times more likely than small PWSs to have PFAS detections. Many large systems have
groundwater sources for supplementary or backup water supply.
Basis for the Interest of the National Ground Water Association (NGWA) in Regulation of PFAS in
Drinking Water
NGWA, the largest trade association and professional society of groundwater professionals in the
world, represents over 10,400 groundwater professionals within the United States and
internationally. NGWA represents four key sectors: scientists and engineers, employed by private
industry, by the consulting community, by academic institutions, and by local, state, and federal
governments, to assess groundwater quality, availability, and sustainability; water-well contractors
responsible for developing and constructing water-well infrastructure for residential, commercial, and
agricultural use; and the manufacturers and the suppliers responsible for manufacturing and
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Comments Received on PFAS
providing the equipment needed to make groundwater development possible. Over 41 million people
in the United States rely on private wells and over 90 million people are served by groundwater from
community water systems. NGWA's mission is to advocate for and support the responsible
development, management, and use of groundwater. Control of potential and active sources of
contamination should be a national objective, reducing the need for remediation of groundwater.
Aquifers should be protected from degradation.
Thank you for the opportunity to comment on this proposed regulatory action.
For further follow up, please contact:
Charles Job, Regulatory Affairs Manager
National Ground Water Association
202-660-0060
cjob@ngwa.org
Individual Response: Please see Discussion on PFAS, General Comments, Other Drinking Water
Programs, and Other EPA Programs.
Comment Excerpt from Commenter 71
While AMWA does not have initial concerns with EPA's inclusion of PFAS as a group on CCL 5, the
association does have concerns with EPA's definition for PFAS included in the notice. EPA has defined
PFAS as those chemicals containing the structure unit R-(CF2)-C(F)(R')R". This definition for PFAS
restricts this group to substances that contain a two-carbon chain, where one carbon is fully
fluorinated and therefore captures far fewer PFAS than other more broad classifications. [FN1:
Organization for Economic Co-operation and Development, 2018. Toward a New Comprehensive
Global Database of Per- and Polyfluoroalkyl Substances (PFASs): Summary Report on Updating The
OECD 2007 List of Per- and
Polyfluoroalkyl Substances (PFASs).
https://www.oecd.org/officialdocu ments/publicdisplaydocumentpdf/?cote=ENVJM-
MONO(2018)7&doclanguage=en ] AMWA is concerned that this restriction excludes PFAS that are
already known to be found in drinking water. For example, perfluoro-2methoxyacetic acid (PFMOAA)
is a perfluoro-ether carboxylic acid that has been found in the North Carolina Cape Fear River and
within nearby drinking water supplies [FN2: North Carolina PFAS Testing Network, 2019. NC PFAST
Quantitative Screening Results for Raw Drinking Water.] [FN3: Hopkins et al., 2018. Recently Detected
Drinking Water Contaminants: GenX and other Per- and Polyfluoroalkyl Ether Acids. Journal AWWA.
https://doi.org/10.1002/awwa.1073 ] but would not be included in the PFAS group under the
definition contained in CCL 5. As a result, this definition is not in line with EPA's stated goal for the
group to be "inclusive of any PFAS (except for PFOA and PFOS)." AMWA suggests that EPA use a
broader definition that will capture all relevant PFAS.
Individual Response: Please see Discussion on PFAS.
Comment Excerpt from Commenter 72
Comments of Arkema Inc. on EPA's NPRM "Drinking Water Contaminant
Candidate List 5-Draft", EPA-HQ-OW-2018-0594
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October 2022
Comments Received on PFAS
Arkema is a global chemical manufacturing company with operations in 22 states and over 3,500
employees, producing innovative solutions for the technologies of the future. In particular, Arkema
manufactures Kynar® PVDF fluoropolymers that are used in a variety of important applications,
including lithium ion batteries, wire and cable jacketing, semiconductors, solar energy, water
filtration, cool roofing and construction coatings that are critical to advancing sustainability. The
lithium ion battery is a necessary component of any electric vehicle.
Arkema has been a pioneer in the reformulation of PVDF fluoropolymers to be produced entirely
without the use of PFAS surfactants. This extraordinary technical innovation required many years of
dedicated R&D efforts. These innovative grades are fully industrialized and commercialized.
As a general matter, we support the transition away from PFAS materials, but we believe the
definition in this regard must be clear so that it does not include fluoropolymers made without the
use of PFAS surfactants.
To that end, we propose to modify the draft definition in the NPRM to the one recently adopted by
the state of Delaware: "PFAS means non-polymeric perfluoroalkyl and polyfluoroalkyl substances that
are a group of man-made chemicals that contain at least 2 fully fluorinated carbon atoms, excluding
gases and volatile liquids". We believe that this definition correctly captures the PFAS chemicals of
concern while leaving out fluoropolymers that have completely different properties.
Fluoropolymers, such as Kynar® PVDF, that meet the OECD "polymer of low concern" criteria are non-
toxic, bio-compatible, non-soluble and immobile molecules, and they are deemed as such to have
insignificant environmental and human health impacts. The properties of these fluoropolymers
enable a durable society as opposed to a disposable society.
Thank you for the opportunity to provide comments.
Sincerely,
Jean-Marie Cencetti
Senior Director Environment & Sustainable Development Arkema, Inc.
Individual Response: Please see Discussion on PFAS. EPA is aware of and considered that multiple
states were developing their own PFAS definitions for statewide efforts, including Delaware. At this
time, EPA is opting to use a more inclusive CCL 5 PFAS definition to represent those chemicals that are
known or anticipated to occur in public water systems and is not prematurely excluding volatiles or
fluoropolymers from further evaluation.
Comment Excerpt from Commenter 73
September 17, 2021
EPA-HQ-OW-2018-0594
EPA Docket Center - Water Docket
U.S. Environmental Protection Agency
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Comments Received on PFAS
Mail Code 28221T
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Re: Fifth Contaminant Candidate List under the Safe Drinking Water Act - notice
of availability, request for comment (86 Federal Register 37948, July 19, 2021)
To Whom It May Concern:
The American Chemistry Council (ACC) submits the following comments on the draft list of
contaminants for inclusion on the fifth Contaminant Candidate List (CCL 5) established under Section
1412(b)(l)(B)(i) of the Safe Drinking Water Act (SDWA). ACC supports the identification of individual
per- and polyfluoroalkyl substances (PFAS) that meet the criteria for inclusion on the CCL established
by the Agency, but strongly opposes the proposal to include the entire class of PFAS on the CCL 5. The
draft proposal and supporting documentation have not provided evidence to support a finding that all
PFAS "present the greatest public health concern" [FN1: 86 Federal Register 37950.] related to
drinking water exposure or even that all members of the class are reasonably anticipated to occur in
public water systems. Consequently, EPA cannot determine that most PFAS compounds meet the
three criteria required for regulatory action under Section 1412(b)(l)(B)(ii) of the Act, as amended in
1996.
When finalized, the CCL 5 will serve as the primary basis for selecting contaminants to be evaluated
for national primary drinking water regulations (NPDWRs) under the provisions of the SDWA. The Act
directs EPA 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. Section 1412(b)(l)(B)(ii) of the Act requires EPA to make determinations of
whether to issue a NPDWR for no fewer than five contaminants from the CCL every 5 years, using the
following criteria -
• 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.
As explained below, EPA has identified no scientific basis for considering that all PFAS are likely to
meet these three criteria. Indeed, it is clear from the scientific evidence that all PFAS compounds do
not meet these criteria.
According to EPA, there are more than 1,000 PFAS compounds listed on the TSCA inventory and at
least 669 that have been active in commerce since 2006. [FN2: USEPA. TSCA Section 8(a)(7) Reporting
and Recordkeeping Requirements for Perfluoroalkyl and Polyfluoroalkyl Substances. Proposed Rule.
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Comments Received on PFAS
86 Federal Register 33926 (June 28, 2021).] For most of these substances, EPA has little or no
information on potential health and environmental effects and, therefore, the Agency cannot assess
whether they present a public health concern. For example, EPA has established or proposed a
chronic reference dose (RfD) for four PFAS. EPA cannot conclude based on those four assessments
that all PFAS should be included on the CCL because all "may have an adverse effect on the health of
humans." Indeed, substances in the broad category of PFAS identified as fluoropolymers satisfy the
criteria for being polymers of low concern established by the Organization of Economic and
Cooperative Development (OECD) criteria. According to the European Environmental Bureau,
fluoropolymers "have negligible solubility, low mobility, large physical size, low biological uptake and,
hence, lower (eco)toxicological concern." [FN3: European Environmental Bureau. PFASs - Avoiding
the streetlight effect: An overview of the current situation in the EU (July 15, 2020), at 6.
https://eeb.org/library/pfass-avoiding-the-streetlight-effect/ ] It is unlikely that a finding of health risk
can be made for this group of PFAS compounds.
Regarding the likelihood that all PFAS are known, or likely, to be found in public water systems, EPA
has identified just a few PFAS compounds in drinking water systems. While the number of PFAS that
can reliably be measured in drinking water will likely continue to increase from the current list of 29,
[FN4: All 29 PFAS are proposed for inclusion in the fifth Unregulated Contaminant Monitoring Rule (86
Federal Register 13846) per the requirements of National Defense Authorization Act (Public Law 116-
92).] it is unlikely that all of the substances captured in the definition of PFAS will be found in drinking
water or that the Agency will ever develop methods to measure all those PFAS that may be found.
Moreover, unlike the two other chemical groups included in the CCL 5 proposal (i.e., cyanotoxins and
unregulated disinfection byproducts), many PFAS would not be expected to be found in drinking
water. Fluoropolymers, for example, are not water-soluble and will not be found in public water
systems. In addition, many compounds that meet the proposed definition of PFAS are present as
gases under environmental conditions and typically will not remain in drinking water supplies.
With regard to the third SDWA criteria that a drinking water regulation will result in a meaningful
health risk reduction for persons served by a public water system, EPA cannot reach this conclusion
for all PFAS compounds. EPA does not know the health risk, if any, of 99 percent of the PFAS present
so it cannot now conclude that all PFAS compounds may cause adverse health effects. Moreover, until
many more PFAS compounds are known to be in drinking water and can be measured in drinking
water, EPA has no basis for concluding that regulation of them will provide a "meaningful opportunity
for health risk reduction for persons served by public water systems."
The Technical Support Document (TSD) for the CCL 5 proposal outlines the following principles used
to achieve the critical goals of the CCL established by the SDWA -
• Classification must consider chemicals for listing based on a consideration of their potential for
occurrence in water and their potential for causing adverse health effects.
• Data supporting the decision to list or not list must be linked back to these criteria. The most
relevant data used for the classification process are health data that indicate adverse effects
associated with chronic oral exposure, and occurrence data that indicate the nature and spatial
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on PFAS
extent of potential occurrence in drinking water.
• The classification approach must be a transparent process that can be reviewed by external experts
and the public. The attributes and data characterizing the contaminants should be easy to understand
and the decision-making process to list or not list a particular chemical must be conveyed in a
straightforward manner. [FN5: USEPA. Technical support document for the draft fifth Contaminant
Candidate List (CCL 5) - chemical contaminants. EPA 815-R-21-005 (July 2021), at 43.]
The TSD asserts that EPA applied this scientific evaluation process to the chemicals it is proposing to
add to the CCL 5, but offers no explanation of how this process was followed for PFAS. Nor does the
document explain how PFAS were found to meet the science-based toxicity and occurrence criteria of
the SDWA. [FN6: In fact, the TSD (page 41) indicates that only 18 individual PFAS were included on the
preliminary CCL 5 list, or PCCL. There is no indication of how or why the Agency departed from this
original plan to consider 18 PFAS for inclusion in CCL 5 to include 1000+ PFAS.] Rather, EPA reasons
that listing several thousand PFAS individually on the CCL 5 would be "difficult and challenging." [FN7:
86 Fed. Reg. at 37962.] The challenge in evaluating a large group of substances is not an appropriate
justification for listing more than a thousand as a class. Nor is it sufficient to suggest that listing is
"responsive to public nominations" recommending inclusion of PFAS chemicals as a class. [FN8:
However Appendix C of the TSD indicates that only 16 individual PFAS, not all PFAS, were nominated
by a public commentator for inclusion on CCL 5.] As a final justification for proposing that all PFAS be
included, EPA reasons that -
[i]ncluding the broad group of PFAS on the Draft CCL 5 demonstrates the agency's commitment to
prioritizing and building a strong foundation of science on PFAS while working to harmonize multiple
authorities to address the impacts of PFAS on public health and the environment. EPA is also
committed to a flexible approach and working collaboratively with states, tribes, water systems, and
local communities that have been impacted by PFAS. [FN9: 86 Federal Register 37962.]
However, including all PFAS on the CCL 5 runs counter to the Agency's attempts to identify and
prioritize those members of the class that warrant further investigation and to building a scientific
foundation for such prioritization. Rather than serve to harmonize efforts to address potential PFAS
impacts, such an "all-in" approach is inconsistent with efforts elsewhere in the Agency to define the
scope of the PFAS issue. Although flexibility is important in working with communities impacted by
PFAS, the lack of a clear set of priorities and focus can only serve to confuse and alarm public water
supply customers.
ACC recognizes that inclusion of contaminants on the CCL 5 is an early step in the regulatory
evaluation process, and that EPA cannot legally establish maximum contaminant limits (MCLs) for
contaminants on the CCL without finding in later stages of the regulatory process that a specific
contaminant meets the statutory criteria of Section 1412(b)(l)(B)(ii) of the SDWA. Indeed, so as not to
create exaggerated expectations, EPA should expressly confirm that contaminants added to the CCL
may be candidates for further consideration as to whether their regulation in drinking water meets
the three statutory criteria. Accordingly, ACC can support the inclusion on the CCL 5 (and on the
UCMR 5) of those individual PFAS for which EPA has developed validated analytical methods.
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on PFAS
National survey data for the PFAS included in UCMR 5 will be collected between 2023 and 2025 and
will provide the Agency with important information on which to evaluate potential drinking water
exposures to PFAS. In the meantime, EPA is expected to develop validated methods for measuring
additional PFAS in drinking water and to continue its efforts to prioritize those PFAS, or properly
defined subclasses of PFAS, for priority consideration of potential public health concerns. As provided
for by the SDWA, and as noted in the proposal, inclusion on the CCL is not a prerequisite for addition
to the UCMR and is not required for the Agency to take future action on a substance found to be of
concern in drinking water. [FN10: Section 1412 (b)(l)(B)(ii)(lll)]
ACC urges EPA to abandon its proposal to add the class of PFAS to the CCL 5. Instead the Agency
should limit listing to those specific PFAS included in the proposed UCMR 5 for which the Agency has
developed analytical methods for drinking water. Thereafter, EPA should determine which, if any,
PFAS to regulate based on whether the specific contaminant meets the statutory criteria of adverse
health effects, presence in public water systems, and a meaningful opportunity for risk reduction.
Please feel free to contact me at 202-249-6727 or at srisotto@amercanchemistry.com if you have
questions about the information provided above.
Sincerely,
Stephen P. Risotto
Senior Director
Individual Response: Please see Discussion on PFAS. General Comments, and Other Drinking Water
Programs. The commenter states that "EPA has identified no scientific basis for considering that all
PFAS are likely to meet these three criteria." The three criteria mentioned in the comment are those
SDWA requires for regulatory determinations and not for CCL.
The commenter recognizes that "flexibility is important in working with communities impacted by
PFAS," and the agency agrees. On the other hand, the agency disagrees with the commenter's
suggestions that a "lack of a clear set of priorities and focus can only serve to confuse and alarm
public water supply customers". CCL is used to set priorities and prompt additional data gathering
which will assist the agency in setting future regulatory priorities and address the public's already
existing concerns about PFAS in drinking water.
Comment Excerpt from Commenter 75
Contaminant Groups
ASDWA generally supports EPA's use of groups on the CCL, however, the agency should provide
clarification on how groups of contaminants will be treated for Regulatory Determinations and UCMR
selection as well as how contaminants within the groups will be prioritized for research.
ASDWA specifically supports EPA placing the per- and polyfluoroalkyl substances (PFAS) group on the
CCL, however there are some concerns regarding the definition of PFAS the Agency is using. In the
proposed rule, EPA states the following regarding the definition of PFAS, "This group is inclusive of
any PFAS (except for PFOA and PFOS). For the purposes of this document, the structural definition of
PFAS includes per- and polyfluorinated substances that structurally contain the unit R-(CF2)-
C(F)(R')R". Both the CF2 and CF moieties are saturated carbons and none of the R groups (R, R' or R")
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on PFAS
can be hydrogen (USEPA, 2021f)." Using this definition limits the group of PFAS to substances that
contain a two-carbon chain, where one carbon is fully fluorinated. This definition undoubtedly
excludes many substances that could otherwise be considered PFAS, including those that have been
found in drinking water and their sources, for example, this definition of PFAS would not include
perfluoro-2-methoxyacetic acid (PFMOAA), a perfluoro-ether carboxylic acid which has been found in
the North Carolina Cape Fear River and nearby drinking water supplies. ASDWA recommends that EPA
reevaluate this definition to be appropriately inclusive of PFAS and should consider revising the
structural definition for PFAS being used by the agency. EPA should consider the definitions used and
developed by the Organization for Economic Co-operation and Development and the Interstate
Technology Regulatory Council. EPA should also recognize that this classification groups together
many substances that will have vastly different overall structures thereby calling into question both
their fate and transport in the environment and the likelihood that they would cause similar adverse
health outcomes. EPA should explain if and how grouping thousands of PFAS for inclusion on the final
CCL 5 will impact the treatment of individual compounds throughout the regulatory determination
process and clarify how and if screening and proxy methods such as the total organic fluorine (TOF)
method will be used.
[Comments on Select Draft CCL 5 Contaminants
The following comments provide additional detail on contaminants listed on the Draft CCL 5 that are a
particular concern for state drinking water programs.]
PFAS
ASDWA supports the inclusion of PFAS as a group on CCL 5. State and territorial drinking water
programs have been confronted over the past several years with how to appropriately address PFAS
challenges. In response to increasing discoveries of PFAS contamination in drinking water sources,
and without a federal enforceable standard for PFAS in drinking water, states that have never
developed drinking water standards in the past are now setting state-level MCLs for the first time. Six
states have state-level MCLs for a subset of PFAS; another four states have set response or action
levels. An additional five states are currently developing standards or guidelines.
Some states are also taking other non-regulatory approaches and actions to assess and address PFAS
in drinking water and more broadly for other media. These approaches and actions include:
developing multi-agency PFAS Action Plans and Response Teams; undertaking PFAS sampling
programs for drinking water systems and surface water and groundwater sources of drinking water;
conducting inventories of facilities that use, have used, or produced PFAS; responding to drinking
water contamination throughout the state and across media (e.g., residuals, effluent discharges,
landfill leachate, Superfund sites); banning use in products; and working with EPA and the
Department of Defense (DoD) to address site specific PFAS contamination. At least 15 states have a
prohibitive law or policy that prevents them from being stricter than federal water standards. PFAS
remain a high priority drinking water contaminant and further research is needed on the thousands of
compounds that make up this chemical class.
Individual Response: Please see Discussion on PFAS and Other Drinking Water Programs. EPA is
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on PFAS
aware of and considered the definitions used and developed by the Organization for Economic Co-
operation and Development and the Interstate Technology Regulatory Council. At this time, EPA is
opting to use a more restrictive CCL 5 PFAS definition that represents those chemicals that are known
or anticipated to occur in public water systems and is not prematurely excluding volatiles or
fluoropolymers from further evaluation.
Comment Excerpt from Commenter 76
The Attorneys General of the States of Connecticut, Delaware, Iowa, Maine, Maryland,
Massachusetts, Minnesota, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Virginia, and
Wisconsin, and the District of Columbia
September 17, 2021
Via Regulations.gov
Water Docket
EPA Docket Center
U.S. Environmental Protection Agency
Mail Code: 28221T
1200 Pennsylvania Ave. NW
Washington, D.C. 20460
Re: Comments on Drinking Water Contaminant Candidate List 5—Draft, 86 Fed. Reg.
37948 (July 19, 2021)
Docket ID No. EPA-HQ-OW-2018-0594
Dear Administrator Regan:
The Attorneys General of the States of Connecticut, Delaware, Iowa, Maine, Maryland,
Massachusetts, Minnesota, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Virginia, and
Wisconsin, and the District of Columbia (collectively, the States) offer these comments in support of
the U.S. Environmental Protection Agency's (EPA) Drinking Water Contaminant Candidate List 5—
Draft (Draft CCL 5), 86 Fed. Reg. 37,948 (July 19, 2021). EPA's Draft CCL 5 lists 66 chemicals, 3
chemical groups (per- and polyfluoroalkyl substances (PFAS), cyanotoxins, and disinfection
byproducts) and 12 microbial contaminants. [FN1: See Drinking Water Contaminant Candidate List
5—Draft (Draft CCL 5), 86 Fed. Reg. 37,948, 37,962 (July 19, 2021) (to be codified at 40 C.F.R. pt. 141).
These comments address only the proposed listing of PFAS as a class]. In these comments, the States
support EPA's proposal to include PFAS as a class of chemicals in CCL 5 as a first step in the process to
consider whether to set drinking water standards for these substances. The States request, however,
that EPA modify the definition of PFAS in the Draft CCL 5 to make it sufficiently comprehensive to
include all of the PFAS identified by EPA and consistent with the definition of PFAS used by the federal
government and states in other contexts.
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Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on PFAS
Background
The Safe Drinking Water Act (SDWA), [FN2: 42 U.S.C. §§ 300f et seq.] section 1412(b)(l)(B)(i), requires
EPA to publish the Drinking Water Critical Contaminant List (CCL) every five years. "The SDWA
specifies that the [CCL] must include contaminants that are not subject to any proposed or
promulgated [national primary drinking water regulations (NPDWRs)], are known or anticipated to
occur in public water systems (PWSs), and may require regulation under the SDWA." FN3: Id. at
37.949], The CCL "serves as the initial screening of potential contaminants/' and the listing "does not
mean that any particular contaminant will necessarily be regulated in the future." [FN4: Id. at
37.950],EPA may select contaminants from the CCL for inclusion in the Unregulated Contaminant
Monitoring Rule (UCMR), which requires public water systems to gather and report occurrence data
for those contaminants. [FN5:ld].The occurrence data produced by the UCMR program may then
provide the basis for EPA's regulatory determination FN6: Id]. The SDWA, section 1412(b)(l)(B)(ii),
requires EPA to make regulatory determinations no less frequently than every five years for at least
five contaminants from the CCL on whether to set NPDWRs for those contaminants.
As stated in the Draft CCL 5, "PFAS are a class of synthetic chemicals that are most commonly used to
make products resistant to water, heat and stains and are consequently found in industrial and
consumer products like clothing, food, packaging, cookware, cosmetics, carpeting and firefighting
foam." [FN7: Id. at 37,962], As EPA notes in the Draft CCL 5, there are "[o]ver 4,000 PFAS that have
been manufactured and used globally since the 1940s [FN8: Id. at 37,962], Although numerous
studies have shown that exposures to PFAS negatively affect human health, there is currently no
national requirement that public water systems test for and remove unsafe levels of PFAS in drinking
water. [FN9: See Announcement of Final Regulatory Determinations for Contaminants on the Fourth
Drinking Water Contaminant Candidate, 86 Fed. Reg. 12,272, 12,278 (Mar. 3, 2021) (to be codified at
40 C.F.R. pt. 141)].
As EPA acknowledges, [FN10: 86 Fed. Reg. at 37,962.] the large number of chemical substances that
are part of the PFAS class makes it difficult to list each of them on the CCL. As set forth below, the
States endorse EPA's proposal to include PFAS as a class in the CCL 5 and make the following specific
recommendations: (A) we urge EPA to define PFAS broadly to ensure that the entire class of PFAS is
included in the CCL 5; and (B) in addition to including PFAS as a class in the CCL 5, we urge EPA to
gather information to consider setting drinking water standards for PFAS as a class.
Discussion
A. The States urge EPA to define PFAS broadly and clearly to ensure that the entire universe of
PFAS is included as a class of chemicals in CCL 5.
While the States support EPA's proposal to include PFAS as a class in CCL 5, we urge EPA to use a
definition of PFAS that is broad enough to actually include the entire universe of PFAS as a class of
chemicals on the CCL 5. [FN11: The States urge EPA to define PFAS broadly in the CCL 5 because it is a
preliminary, investigatory step in the SDWA regulatory process. However, we do not take a position
on how any regulations that may result should be structured or how PFAS as a class should be defined
in later stages of the SDWA regulatory process], EPA states that it is proposing "to list PFAS as a group
inclusive of any PFAS." [FN12: 86 Fed. Reg. 37,962 (July 19, 2021). EPA is not including PFOA and PFOS
in the proposed CCL 5 because EPA has already made final regulatory determinations for those two
PFAS. 86 Fed. Reg. 37,969 (July 19, 2021)]. It acknowledges that "[o]ver 4,000 PFAS have been
manufactured and used globally since the 1940s." [FN13: Id. at 37,962.] By proposing to list PFAS as a
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EPA-OGWDW
Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on PFAS
class inclusive of any PFAS, the States' expectation is that the definition of PFAS in the CCL 5 includes
all PFAS formulations, both currently known PFAS and PFAS that may be created in the future.
Unfortunately, however, the definition of PFAS proposed in the Draft CCL 5 may exclude some PFAS.
The States urge EPA to analyze other definitions of PFAS and choose one that is broader and clearer
than the definition proposed in the Draft CCL 5 to ensure that the entire universe of PFAS is included
in the final CCL 5.
It is important that EPA include a broad definition of PFAS in the CCL 5 because future regulatory
determinations will be made based on that definition. As EPA notes, "[t]he CCL is the first step in the
SDWA regulatory framework for screening and evaluating the subset of contaminants that may
require future regulation." [FN14: Id. at 37,950.] And, "[h]istorically, most unregulated contaminants
chosen by EPA for monitoring" under the Unregulated Contaminant Monitoring Rule (UCMR) "have
been selected from the CCL." FN15: Id.] While listing PFAS on the CCL 5 "does not necessarily mean
that EPA will make subsequent regulatory decisions for the entire group," it does mean that "EPA will
evaluate scientific data on the listed groups, subgroups, and individual contaminants included in the
group to inform any regulatory determinations for the group, subgroup, or individual contaminants in
the group." [FN16: Id. at 37,962.] Because future regulatory decisions may be made for the entire
class of PFAS as defined in the CCL 5 or individual contaminants in the group, it is important that the
definition of PFAS capture the entire universe of PFAS.
In the Draft CCL 5, EPA proposes the following definition of PFAS:
For the purposes of this document, the structural definition of PFAS includes per- and polyfluorinated
substances that structurally contain the unit R-(CF2)-C(F)(R')R". Both the CF2 and CF moieties are
saturated carbons and none of the R groups (R, R' or R") can be hydrogen (USEPA, 2021f).[FN17: Id.]
This is the same definition of PFAS that EPA included in its recently proposed rule "TSCA Section
8(a)(7) Reporting and Recordkeeping Requirements for Perfluoroalkyl and Polyfluoroalkyl Substances"
(TSCA rule). [FN18: 86 Fed. Reg. 33,929 (June 28, 2021) ("For the purposes of this proposed action,
the structural definition of PFAS includes per- and polyfluorinated substances that structurally contain
the unit R-(CF2)-C(F)(R')R". Both the CF2 and CF moieties are saturated carbons and none of the R
groups (R, R' or R") can be hydrogen.")]. In that pending rulemaking, EPA acknowledged that this
definition may only cover a subset—"at least 1,364 chemical substances and mixtures"—of the over
4,000 PFAS that have been manufactured and used [FN19:ld.].
The States are concerned that the definition of PFAS in the Draft CCL 5 may be too narrow to ensure
that the entire universe of PFAS is included in the CCL 5. For example, the definition seems to exclude
fluorinated compounds containing a spacer, such as CH2 or oxygen, between the CF2 and CF groups.
Fluorinated chemicals containing these spacers have been found in environmental testing near PFAS
manufacturing plants [FN20: Newton S, McMahen R, Stoeckel JA, Chislock M, Lindstrom A, Strynar M.
Novel polyfluorinated compounds identified using high resolution mass spectrometry downstream of
manufacturing facilities near Decatur, Alabama, USA. Environ SciTechnol. 2017 February 07; 51(3):
1544-1552. https://doi.org/10.1021/acs.est.6b05330; Zhang C, Hopkins ZR, McCord J, Strynar MJ,
Knappe DRU. Fate of per- and polyfluoroalkyl ether acids in the total oxidizable precursor assay and
implications for the analysis of impacted water. Environ Sci Technol Lett. 2019; 6(11): 662-668.
https://doi.org/10.1021/acs.estlett.9b00525]. The definition also seems to exclude fluorinated
compounds that contain only one CF3 group, such as some fluorinated gases, pesticides,
pharmaceuticals, and dyes. The definition of PFAS should be modified to be broad enough to include
chemicals containing spacers and a single CF3 group. The States are also concerned that the current
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EPA-OGWDW
Draft CCL 5 Response to Comments
EPA 815-R-22-001
October 2022
Comments Received on PFAS
definition may not be clear enough to accurately describe the entire universe of PFAS. In this regard,
the Draft CCL 5 is not clear as to whether one of the R groups (R, R', or R") can be halogens other than
fluorine or include one or more CH2 molecules and still be included in the definition of PFAS. Also, it is
not clear why none of the R groups can be hydrogen—this requirement narrows the definition.
Recent State and Federal legislation have adopted definitions of PFAS that are simpler and may be
broader and more inclusive than the Draft CCL 5 definition. For example, the 2021 National Defense
Authorization Act (2021 NDAA) defines PFAS as "a perfluoroalkyl or polyfluoroalkyl substance with at
least one fully fluorinated carbon atom, including the chemical GenX." FN21: William M. (Mac)
Thornberry National Defense Authorization Act for Fiscal Year 2021, Pub. L. No. 116-283, § 335(e)(2)
(2021)]. Similarly, Vermont recently enacted a statute defining PFAS as "a class of fluorinated organic
chemicals containing at least one fully fluorinated carbon atom." [FN22: Vt. Stat. Ann. tit. 18, §
1661(5) (effective July 1, 2022); 2021 Vt. Acts & Resolves 36, § 1.]
EPA should analyze these and other available definitions of PFAS against the proposed
definition of PFAS in the Draft CCL 5 before issuing the final CCL 5. The States urge EPA to choose the
broadest and clearest definition to ensure that, consistent with EPA's stated intent, the final CCL 5
includes the entire universe of PFAS as a class of chemicals on the CCL 5.
B. The States support EPA's proposal to include PFAS as a class in the CCL 5, and we urge EPA to
gather information to consider setting drinking water standards for PFAS as a class.
The States support EPA's proposal to include PFAS as a class in the CCL 5. Clearly, PFAS meet the
SDWA criteria for listing in the CCL.[FN23: 42 U.S.C. § 300g-l(b))(l)(B)(i)]. First, PFAS as a class are not
currently regulated under the SDWA. [FN24: See Announcement of Final Regulatory Determinations
for Contaminants on the Fourth Drinking Water Contaminant Candidate, 86 Fed. Reg. 12,272, 12,278
(Mar. 3, 2021) (to be codified at 40 C.F.R. pt. 141)]. Second, PFAS are known or anticipated to occur in
public water systems. [FN25: For a summary of occurrence data for PFAS other than PFOA and PFOS,
see Attorneys General of Wisconsin et al., Comment Letter on the Preliminary Determinations for
Contaminants on the Fourth Drinking Water Contaminant Candidate List 12-18 (May 10, 2021),
https://www.doj.state.wi.us/sites/default/files/news-media/6.10.20_PFAS_Letter.pdf], Third, PFAS
may require regulation under the SDWA due to their prevalence in drinking water supplies and public
health impacts. This listing is a significant first step in EPA's consideration of whether to set drinking
water standards under the SDWA for PFAS as a class. We urge EPA to move forward quickly to gather
occurrence data on PFAS as a class in public water systems and to evaluate whether to set drinking
water standards for PFAS as a class.
PFAS contamination detected in the environment is generally made up of mixtures of PFAS, which
often contain PFOA or PFOS, two specific PFAS. [FN26: See, e.g., Balan SA, Mathrani VC, Guo DF,
Algazi AM. Regulating PFAS as a Chemical Class under the California Safer Consumer Products
Program. Environ. Health Perspectives 2021 Feb 17;129(2). https://doi.Org/10.1289/EHP7431.1 This
PFAS mixture results from multiple sources of PFAS present in an area, the use of PFAS as mixtures in
single products (e.g., fire-fighting foam or aqueous film forming foam (AFFF)), and the changes in the
types of PFAS that have been commonly used over time. Mixtures of PFAS may pose similar health
risks to those associated with exposure to PFOA or PFOS alone, contaminants whose public health
impact is well documented. [FN27: Id].
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Comments Received on PFAS
A class-based approach may be the most effective way to regulate PFAS as it would provide increased
protection to the public, decrease the burden on regulatory agencies, and provide greater certainty to
the operators of public water systems. Indeed, regulation of specific PFAS in the past has led to their
replacement with other PFAS with similar hazards. [FN28: Balan SA, Mathrani VC, Guo DF, Algazi AM.
Regulating PFAS as a Chemical Class under the California Safer Consumer Products Program. Environ.
Health Perspectives 2021 Feb 17;129(2). https://doi.org/10.1289/EHP7431], PFAS generally show
similar indicia of toxicity, environmental persistence (hence, the common reference to PFAS as
"forever" chemicals), bioaccumulation, and ubiquity in the environment. [FN29: Addition of Certain
Per-and Polyfluoroalkyl Substances; Community Right-to-Know Toxic Chemical Release Reporting
(ANPRM), 84 Fed. Reg. 66,369 (Dec. 4, 2019); USEPA. EPA's Per- and Polyfluoroalkyl Substances (PFAS)
Action Plan. EPA 823R18004. U.S. Environmental Protection Agency, Washington, D.C. February
2019], One of the most consistent features of the PFAS class is that, despite the diversity of PFAS
substances, all PFAS are extremely resistant to environmental and metabolic degradation. [FN30:
Cousins IT, DeWitt JC, Gliige J, Goldenman G, Herzke D, Lohmann R, Ng CA, Scheringer M, Wang Z. The
high persistence of PFAS is sufficient for their management as a chemical class. Environ Sci Process
Impacts. 2020 Dec 16;22(12):2307-2312. https://pubmed.ncbi.nlm.nih.gov/33230514/; Kwiatkowski
CF, Andrews DQ, Birnbaum LS, Bruton TA, DeWitt JC, Knappe D, Maffini MV, Miller MF, Pelch KE,
Reade A, Soehl A, Trier X, Venier M, Wagner CC, Wang Z, Blum A. Scientific Basis for Managing PFAS as
a Chemical Class. Environ. Sci. Technol. Lett. 2020 Jun 30;7, 8:532-543.
https://doi.org/10.1021/acs.estlett.0c002551.There is also a growing body of evidence that shorter-
chained PFAS have similar toxicological effects to the well documented adverse effects of longer-
chained PFAS such as PFOA and PFOS. [FN31: Kwiatkowski CF, Andrews DQ, Birnbaum LS, Bruton TA,
DeWitt JC, Knappe D, Maffini MV, Miller MF, Pelch KE, Reade A, Soehl A, Trier X, Venier M, Wagner
CC, Wang Z, Blum A. Scientific Basis for Managing PFAS as a Chemical Class. Environ. Sci. Technol. Lett.
2020 Jun 30;7, 8:532-543. https://doi.org/10.1021/acs.estlett.0c00255].
As EPA recognizes in its notice of this proposed action, listing the many individual PFAS in the CCL 5
would be challenging and impractical, while listing PFAS as a class squares with EPA's commitment to
better understand and then reduce the potential risks caused by this broad class of chemicals. [FN32:
86 Fed. Reg. at 37,962] Similarly, it is neither practical nor desirable for EPA to regulate PFAS on an
individual basis. Attempting to regulate the over 4,000 known PFAS individually, let alone the
potentially never-ending succession of formulations that may regrettably emerge, is a recipe for
failing adequately to protect the public. We acknowledge that there are also practical and technical
challenges to regulating PFAS as a class in drinking water or other environmental media. These
challenges are potentially different than those posed by regulating PFAS as a class in other settings,
such as the regulation of consumer products. In these comments, we do not address the challenges to
regulating PFAS as a class in drinking water. At this stage, we urge EPA to gather the information
needed to consider regulating PFAS as a class in the future.
We also applaud EPA's recent actions to regulate individual PFAS and to gather data for other
individual PFAS. On June 10, 2020, many of the undersigned States [FN33: The Attorneys General of
the States of California, Colorado, Connecticut, Delaware, Illinois, Iowa, Maine, Maryland,
Massachusetts, Minnesota, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon,
Pennsylvania, Rhode Island, Virginia, Washington, and Wisconsin, and the District of Columbia
submitted joint comments in support of EPA's proposed decision to set drinking water standards for
PFOS and PFOA.] submitted comments in support of EPA's proposed decision to set drinking water
standards for two PFAS—perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA)—
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Comments Received on PFAS
which EPA announced in its Preliminary Regulatory Determinations for Contaminants on the Fourth
Drinking Water Contaminant Candidate List [FN34: Preliminary Regulatory Determinations for
Contaminants on the Fourth Drinking Water Contaminant Candidate List (Preliminary Determination),
85 Fed. Reg. 14,098, 14,120 (Mar. 10, 2020)]. Some of the States [FN35: The Attorneys General of the
States of California, Colorado, Connecticut, Delaware, Illinois, Iowa, Maine, Maryland, Massachusetts,
Minnesota, New Mexico, Oregon, North Carolina, Pennsylvania, Rhode Island, Virginia, Washington,
and Wisconsin, and the District of Columbia submitted joint comments in support of EPA's proposal to
include 29 PFAS in the UCMR 5.] also recently submitted comments in support of EPA's proposal to
include 29 PFAS in the UCMR 5. [FN36: Attorneys General of Wisconsin et al., Comment Letter on the
Proposed Rule, Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 5) (May 10, 2021),
https://www.doj.state.wi.us/sites/default/files/news-media/510.21_PFAS_Comments.pdf.] Including
these individual PFAS in the UCMR 5 will provide vital information about the occurrence of these
contaminants in public water systems. However, to evaluate fully the public health protections
needed with respect to PFAS in drinking water, we urge EPA to gather such data about PFAS as a class.
The States therefore urge EPA to gather occurrence data for PFAS as a class. One way to do so is
through the UCMR program. Accordingly, in comments on the UCMR 5, some of the undersigned
States urged EPA to include PFAS as a class so that important helpful data may expeditiously be
gathered. [FN37: Attorneys General of Wisconsin et al., Comment Letter on the Proposed Rule,
Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 5) (May 10, 2021),
https://www.doj.state.wi.us/sites/default/files/news-media/510.21_PFAS_Comments.pdf. .] Whether
through the UCMR program or other means, gathering such data is an important step in setting
appropriately protective drinking water standards for these groups of contaminants.
Conclusion
The States appreciate the opportunity to submit these comments on the Draft CCL 5 and fully support
EPA's inclusion of PFAS as a class in the CCL 5. The States also urge EPA to define PFAS as a class
broadly to ensure that the entire universe of PFAS is included in the CCL 5. In addition to including
PFAS as a class in the CCL 5, we urge EPA to gather the information necessary to move forward
expeditiously in considering setting drinking water standards for PFAS as a class.
Sincerely,
FOR THE STATE OF WISCONSIN
JOSHUA L. KAUL
Attorney General of Wisconsin
By: /s/ Sarah C. Geers
SARAH C. GEERS
By: /s/ Bradley J. Motl
BRADLEY J. MOTL
Assistant Attorneys General
Wisconsin Department of Justice
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Post Office Box 7857
Madison, Wisconsin 53707-7857
Phone: (608) 266-3067 (Geers)
(608) 267-0505 (Motl)
Email: geerssc@doj.state.wi.us
motlbj@doj.state, wi. us
FOR THE COMMONWEALTH OF PENNSYLVANIA
JOSH SHAPIRO
Attorney General of Pennsylvania
By: /s/ Ann Johnston
ANN JOHNSTON
Senior Deputy Attorney General
Office of Attorney General
Strawberry Square 14th Floor
Harrisburg, PA 17120
Phone:(717)705-6938
Email: ajohnston@attorneygeneral.gov
FOR THE STATE OF CONNECTICUT
WILLIAM TONG
Attorney General of Connecticut
By: /s/ Jill Lacedonia
JILLLACEDONIA
Assistant Attorney General
Connecticut
Office of the Attorney General
165 Capitol Avenue
Hartford, CT 06106
Phone: (860) 808-5250
Email: Jill.Lacedonia@ct.gov
FOR THE STATE OF DELAWARE
KATHLEEN JENNINGS
Attorney General of Delaware
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By: /s/ Christian Douglas Wright
CHRISTIAN DOUGLAS WRIGHT
Director of Impact Litigation
Delaware Department of Justice
820 N. French Street, 5th Floor
Wilmington, DE 19801
Phone:(302) 577-8600
Email: christian.wright@delaware.gov
FOR THIS DISTRICT OF COLUMBIA
KARL A. RACINE
Attorney General of the
District of Columbia
By: /s/ Kathleen Konopka
Kathleen Konopka
Deputy Attorney General
Office of the Attorney General
for the District of Columbia
441 Fourth Street N.W.
Suite 650 North
Washington, D.C. 20001
Email: Kathleen.Konopka@dc.gov
FOR THE STATE OF IOWA
TOM MILLER
Attorney General of Iowa
By: /s/ David S. Steward
DAVIDS. STEWARD
Assistant Attorney General
Iowa Attorney General's Office
1305 E. Walnut St., Second Fl.
Des Moines, IA 50319
Phone:(515) 281-7242
Email: david.steward@ag.iowa.gov
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FOR THE STATE OF MAINE
AARON FREY
Attorney General of Maine
By: /s/ Katherine Tierney
KATHERINE TIERNEY
Assistant Attorney General
Office of the Attorney General
6 State House Station
Augusta, Maine 04333
Phone:(207) 626-8897
Email: katherine.tierney@maine.gov
FOR THE STATE OF MARYLAND
BRIAN E. FROSH
Attorney General of Maryland
By: /s/ Steven J. Goldstein
Steven J. Goldstein
Special Assistant Attorney General
Office of the Attorney General
200 Saint Paul Place, 20th Floor
Baltimore, Maryland 21202
Phone: (410) 576-6414
Email: sgoldstein@oag.state.md.us
FOR THE COMMONWEALTH OF
MASSACHUSETTS
MAURA HEALEY
Attorney General of Massachusetts
By: /s/ I. Andrew Goldberg
I. ANDREW GOLDBERG
Assistant Attorney General
Environmental Protection Division
One Ashburton Place, 18th Floor
Boston, MA 02108
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Phone:(617)963-2294
Email: andy.goldberg@mass.gov
FOR THE STATE OF MINNESOTA
KEITH ELLISON
Attorney General of Minnesota
By: /s/ Peter N. Surdo
PETER N. SURDO
Special Assistant Attorney General
Minnesota Attorney General's Office
445 Minnesota Street
Town Square Tower Suite 1400
Saint Paul, Minnesota 55101
Phone: 651.757.1061
Email: Peter.Surdo@ag.state.mn.us
FO R TH E STATE O F N EW J E RSEY
ANDREW J. BRUCK
Acting Attorney General
By: /s/ Gwen Farley
GWEN FARLEY
Deputy Attorney General
Department of Law and Public Safety
Division of Law
Environmental Enforcement
and Environmental Justice Section
P.O. Box 093
25 Market Street, 7th Floor
Trenton, NJ 08625-0093
Phone:(609)376-2740
Email: Gwen.Farley@law.njoag.gov
FOR THE STATE OF NEW MEXICO
HECTOR BALDERAS
Attorney General of New Mexico
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By: /s/ William Grantham
WILLIAM GRANTHAM
Assistant Attorney General
State of New Mexico Office of the Attorney General
Consumer & Environmental Protection Division
408 Galisteo Street
Villagra Building
Santa Fe, NM 87501
Phone:(505) 717-3520
Email: wgrantham@nmag.gov
FOR THE STATE OF NEW YORK
LETITIA JAMES
Attorney General of New York
By: /s/ Matthew J. Sinkman
Matthew J. Sinkman
Philip Bein
John D. Davis
Environmental Protection Bureau
28 Liberty Street, 19th Floor
New York, New York 10005
Phone:(212) 416-8446
FOR THE STATE OF OREGON
ELLEN F. ROSENBLUM
Attorney General of Oregon
By: /s/ Paul Garrahan
PAULGARRAHAN
Attorney-in-Charge,
Natural Resources Section
Oregon Department of Justice
1162 Court Street, N.E.
Salem, OR 97301-4096
Phone: (503) 947-4593
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Fax: (503) 378-3784
Email: Paul.Garrahan@doj.state.or.us
FOR THE COMMONWEALTH OF
VIRGINIA
MARK R. HERRING
Attorney General of Virginia
By: /s/ Christopher E. Bergin, Jr.
Christopher E. Bergin, Jr.
Assistant Attorney General
Environmental Section
202 N. 9th Street
Richmond, Virginia 23219
Phone: (804) 786-8480
Email: cbergin(5)oag.state.va.us
Individual Response: Please see Discussion on PFAS. General Comments, and Other Drinking Water
Programs.
Comment Excerpt from Commenter 77
[AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.]
Using CCL to Advance Source Water Protection
The CCL should inform risk management efforts beyond the scope of SDWA. This is especially
important for contaminants like PFAS, where the source of the contamination is beyond the
authorities of SDWA. In developing and presenting the CCL, EPA should consider how it can leverage
this information to inform discussion about chemicals that may pose a risk to the nation's drinking
water supply. For example, PFAS are a group of contaminants most appropriately addressed through
the Toxic Substances Control Act, CWA, and Resource Conservation and Recovery Act. There are
opportunities for federal agencies other than EPA to fund relevant research, employ policies and
procedures that reduce the use of PFAS substances (e.g., Department of Defense, General Services
Administration, etc.).
For other contaminants, other federal agencies may be most relevant to exposure reduction (e.g.,
Food and Drug Administration, U.S. Department of Agriculture, etc.). In order for EPA to effectively
leverage CCL 5 to reduce contaminant occurrence, the final Federal Register notice must provide a
sense of priority for (1) which contaminants appear to pose the greatest priority for action and (2)
research and data development needs to inform decision-making.
The CCL development process occurs over a five-year cycle. There are frequently stated concerns that
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the SDWA regulatory process is too slow. The CCL is an opportunity for EPA to step beyond that
critique and move instead to timely initiation of action not only to inform risk in drinking water but
contamination of the nation's waters.
Individual Response: Please see Discussion on PFAS, Other Drinking Water Programs, and Other EPA
Programs.
Comment Excerpt from Commenter 77
Specific CCL5 Contaminants
Appropriately Define PFAS
The Draft CCL 5 includes PFAS as a group of chemical contaminants. EPA describes the structural
definition as, intended to be, inclusive of all PFAS compounds. Specifically the EPA has defined PFAS
as chemicals with the chemical structure R-(CF2)-C(F)(R')R" where the CF2 and CF moieties are
saturated carbons and none of the R groups can be hydrogen. This definition is based on the
definition of PFAS included in a recently proposed TSCA Rule. [FN26: EPA, 2021. TSCA Section 8(a)(7)
Reporting and Recordkeeping Requirements for Perfluoroalkyl and Polyfluoroalkyl Substances.] Under
that rule, EPA indicated that approximately 1,346 PFAS meet this definition. This definition does not
include all PFAS. The accepted definition of PFAS broadly is those substances containing at least one
fluorinated carbon moiety. [FN27: Buck et al, 2011. Perfluoroalkyl and Polyfluoroalkyl Substances in
the Environment: Terminology, Classification, and Origins. Integrated Environmental Assessment and
Management. Doi: 10.1002/ieam.258.] [FN28: Organization for Economic Co-operation and
Development, 2018. Toward a New Comprehensive Global Database of Per- and Polyfluoroalkyl
Substances (PFASs): Summary Report on Updating The OECD 2007 List of Per- and Polyfluoroalkyl
Substances (PFASs). https://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=ENV-
JM-MONO(2018)7&doclanguage=en] [FN29: EPA, 2020. EPA: PFAS Structures in DSSTox (Update
August 2020). https://comptox.epa.gov/dashboard/chemical_lists/PFASSTRUCTV3] According to the
EPA CompTox PFAS Master List there are approximately 9,252 known PFAS chemicals, a much larger
universe of PFAS compounds than what is included by the definition in the Draft CCL 5.
The Draft CCL 5 definition for PFAS excludes certain PFAS that have been found in drinking water and
their sources from the proposed reporting requirements. For example, perfluoro-2-methoxyacetic
acid (PFMOAA) does not meet the structural definition since this compound does not have a
fluorinated tnwo-carbon chain. However, PFMOAA is a perfluoro-ether carboxylic acid that has been
found in the North Carolina Cape Fear River and nearby drinking water supplies. [FN30: North
Carolina PFAS Testing Network, 2019. NC PFAST Quantitative Screening Results for Raw Drinking
Water. https://www.brunswickcountync.gov/wp-content/uploads/2019/08/NC-PFAST-Quantitative-
Screening-Results-for-Raw-Drinking-Water-Brunswick-County-Drinking-Water-System.pdf ] [FN31:
Hopkins et al., 2018. Recently Detected Drinking Water Contaminants: GenX and other Per- and
Polyfluoroalkyl Ether Acids. Journal AWWA. https://doi.org/10.1002/awwa.1073] PFMOAA is an
example of a replacement PFAS being used as legacy PFAS compounds (e.g., PFOA and PFOS) are
phased out. If EPA anticipates using an all-inclusive structural definition of PFAS, then the appropriate
chemical structure would be R-CF(R')(R"), where R, R', and R" are not hydrogen.
If EPA includes PFAS as a group in the final CCL 5, then it should be intentional and transparent in its
inclusion and the chemical structures it is including. The framing of the CCL is as important as the list
itself. As EPA notes, the current inclusion of 1,346 PFAS compounds assumes a common level of
toxicity that is not substantiated in the docket and a premise that would be even less credible if
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applied to 9,252 PFAS compounds. This is an instance where, if EPA were to more clearly
communicate the relative levels of potential risk and gaps in information needed to craft risk
management decisions, it could more readily incorporate a group (or groups) of PFAS on the Final CCL
5.
Individual Response: Please see Discussion on PFAS and Other EPA Programs.
Comment Excerpt from Commenter 78
Submitted electronically via the Federal eRulemaking portal at www.regulations.gov
September 17, 2021
EPA Docket Center, Water Docket
Environmental Protection Agency
Mail code: 28221T
1200 Pennsylvania Ave. NW
Washington, DC 20460
Re: Drinking Water Contaminant Candidate List 5 - Draft: Proposed Rule Docket ID: EPA-HQ-OW-
2018-0594
Dear Sir or Madam:
The 3M Company ("3M") appreciates the opportunity to comment on the proposed
Drinking Water Contaminant Candidate List 5 ("CCL 5") published by the Environmental Protection
Agency ("EPA") at 86 Fed. Reg. 37948 on July 19, 2021. As a science-based company, 3M appreciates
the efforts EPA has made to take a science-based approach to the CCL 5. In particular, 3M supports
EPA's approach to screening substances for potential inclusion on the CCL 5. It is important that EPA
maintain this science-based approach with regard to its consideration of per- and polyfluoroalkyl
substances ("PFAS"), particularly when considering broad regulatory actions, such as grouping PFAS
with known variations in chemistries, and making decisions about application of the screening criteria
to PFAS.
Today's PFAS compounds are used by a broad range of customers and industries worldwide
that enable critical products such as life-saving medical devices and low-emission vehicles. Regulatory
policy must take these important applications into account. While the science behind PFAS can be
complex and continues to evolve, science must be at the forefront of providing answers and
solutions. 3M encourages EPA to apply the same scientific standards consistently across all
contaminant candidates and to consider the feasibility of the proposed CCL 5 listing. We look forward
to continued engagement in these and other important discussions around PFAS.
I. Groupings Can be Useful, But EPA Should Not List PFAS as an Undifferentiated Chemical
Group
PFAS refers to a broad category of compounds that encompasses thousands of materials with distinct
and widely varying properties, profiles, and uses. As EPA has noted, "PFAS vary widely in chemical and
physical properties, behavior, and potential risks to human health and the environment. Differences
in the chemical structure, carbon chain length, degree of fluorination, and chemical functional
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group(s) of individual PFAS have implications for their mobility, fate, and degradation in the
environment, as well as uptake, metabolism, clearance, and toxicity in humans, plants, and other
animals." EPA Multi-Industry Per- and Polyfluoroalkyl Substances (PFAS) Study - 2021 Preliminary
Report ("EPA PFAS Study") at 3-1 (September 2021). [FN1: EPA published the Multi-Industry PFAS
Study - 2021 Preliminary Report on September 16, 2021, one day before the submission deadline for
comments on the draft CCL 5. There is a significant amount of relevant information regarding the
"family" of PFAS that 3M suggests EPA incorporate into its CCL 5 listing proposal.] As a result, treating
all PFAS as a single group or class is not scientifically sound or appropriate. At the same time, we
understand some parties' desire to reduce the volume of individual regulatory assessments through
groupings or sub-groupings. We therefore support a rigorous, science based dialogue and review
among regulators, academic researchers, manufacturers, and others to determine how these
materials could be potentially be grouped in a scientifically sound way.
Consistent with sound environmental policy, such assessments must not only be based on the best
available science, but also specific ways in which these substances may or may not impact human
health and the environment. Such assessments should consider potential exposure routes and
identified hazards, not simply structural similarities. Furthermore, to reach a positive outcome for the
communities that regulators serve, these ongoing discussions must be measured and thoughtful to
yield effective solutions for use in critical regulatory applications.
a. The Proposed Definition of PFAS is Not Scientifically Sound
In the draft CCL 5, EPA proposes to define PFAS as follows [FN2: EPA's proposed definition of PFAS is
the same as what it proposes in the proposed TSCA Section 8(a)(7) Reporting and Recordkeeping
Requirements for Perfluoroalkyl and Polyfluoroalkyl Substances, 86 FR 33926, June 28, 2021 ] :
For the purposes of this document, the structural definition of PFAS includes per- and polyfluorinated
substances that structurally contain the unit R-(CF2)- C(F)(R')R". Both the CF2 and CF moieties are
saturated carbons and none of the R groups (R, R' or R") can be hydrogen (USEPA, 2021f).
This definition of PFAS presents significant problems. EPA has acknowledged that the proposed
definition "is responsive to public nominations which stated that EPA should 'include PFAS chemicals
as a class on CCL 5."' 86 Fed. Reg. at 37962. For such broad groups of substances, it is critical that this
definition is science-based and rooted in appropriate appreciation of the many implications that such
a definition could hold.
First, this definition is inconsistent with other regulatory definitions and is not recognized by any
other federal or international organization. Moreover, the definition includes substances that EPA
specifically excluded from the proposed candidate contaminant list ("PCCL"). Specifically, EPA
excluded PFOA and PFOS from the PCCL because it already made regulatory determinations for those
substances. The proposed definition itself makes no such distinction. Given the importance of
accurate regulatory definitions, 3M encourages EPA to ensure its proposal is as clear and scientifically
sound as possible.
Second, EPA's PFAS definition as drafted is both over- and under-inclusive. The definition is over-
inclusive because, as noted above and as EPA itself acknowledges, the range of substances
encompassed by the definition includes substances with widely varying toxicity, fate and transport,
and other characteristics. EPA acknowledges that data availability regarding health effects and
occurrence varies significantly within the defined PFAS group, but nonetheless lists the entire group
based on "a subset of chemicals" in the group that are known to occur and "may cause" adverse
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health effects. EPA states that it "did not assess data availability for the cyanotoxins, DBPs, and PFAS
groups because the availability of health effects and occurrence data varies with individual chemicals
in each group. EPA is addressing these groups broadly in drinking water based on a subset of
chemicals in these groups that are known to occur in PWSs and may cause adverse health effects." Id.
at 37970. EPA does not identify the "subset of chemicals" it is basing this determination on with
respect to PFAS. This is particularly troubling given that EPA is excluding PFOA and PFOS from its
listing (but not definition) of PFAS. Further, EPA has not cited any occurrence or health effects
information indicating treatment of the defined PFAS as an undifferentiated group is appropriate. In
fact, EPA has not identified any scientific basis to group thousands of substances without any
distinction. 3M has not identified any precedent in EPA's prior regulatory actions for grouping
thousands of chemicals with such widely varying characteristics.
At the same time, EPA also excluded components of significant groups of fluorinated substances from
its PFAS definition. Hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), and
hydrochlorofluoroolefins (HCFOs) are all PFAS in that they contain at least one perfluoroalkyl moiety,
yet EPA's proposed definition of PFAS excludes certain substances in these groups. For example, the
definition excludes CF3CH2CF2CH3, which has CF3 and CF2 moieties but does not have adjacent
fluorinated carbons. Likewise, although it has it two adjacent fluorinated carbons, CF3CFH2 is
excluded from EPA's PFAS definition because it contains an H atom in an "R" position. Indeed, EPA's
PFAS definition excludes nearly all commercially significant HFCs and HFOs/HCFOs used as solvents,
refrigerants, foam blowing agents, etc., as well as a number of pharmaceuticals and anesthetics
containing CF3 or CF2 groups because, in many cases, there are alternating moieties. EPA has not
identified any scientific basis to exclude these or certain other HFCs, HFOs, and HCFOs from its PFAS
definition.
It is vital that the proposed PFAS definition is fair and consistently applied to substances based on
substances' environmental, health, and safety profiles. To the extent EPA has a scientific basis to
exclude HFCs, HFOs, and HCFOs from the CCL 5 listing, it should also review the broad but incomplete
group of PFAS included in its current definition. Many PFAS are included in EPA's definition despite
there being little difference in the environmental, health, and safety properties from the compounds
excluded. EPA should either propose more narrow definitions focused on appropriate science-based
sub-groupings (based on similarity of characteristics), or it should expand the definition of PFAS to
include the full array of fluorinated substances, including all HFCs, HFOs, and HCFOs.
b. Treating PFAS as an Undifferentiated Group is Inconsistent With EPA's Treatment of Chlorinated
Organic Compounds
EPA's proposal to treat PFAS as a single undifferentiated group is inconsistent with EPA's approach to
another class of organohalogens: chlorinated organic compounds. There are more than 2,000
chlorinated organic compounds. [FN3: See, e.g., https://www.eurochlor.org/term/organic-
chlorinecompounds/#:~:text=0rganic%20chlorine%20compounds%20constitute%20a,one%20or%20
more%20chlorine%20 atoms.] Analytical test methods and approaches to assess human and
environmental risk have been established for individual chlorinated organic compounds as well as
sub-groups of those compounds. Chlorinated organic compounds are divided into several groups
based primarily on chemical structure within those sub-groups and use. Examples of these sub-groups
include:
• Polychlorinated Biphenyl's (PCBs)
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• Polychlorinated Dibenzodioxins and Furan (PCDDs/PCDFs)
• Chlorinated Solvents (i.e., dichloromethane, tetrachloroethylene)
• Chlorinated Pesticides (i.e., atrazine, metholachlor, DDT, hexachlorocyclohexanes (HcHs))
• Chlorinated hydrocarbons
• Chlorinated Phenols (i.e., 2, 4 Dicholorphenol)
• Chlorobenzenes
• Pharmaceuticals containing chlorine
In addition, EPA has developed and validated analytical test methods for nearly 500 individual
chlorinated compounds within classes of chlorinated organic compounds in a variety of
environmental matrices (i.e., air, water, and solid waste). [FN4: Such analytical methods include EPA
Methods 505, 508, 515.1, 551, 508; Methods 608, 612, and 615; Methods 1613, 1653, and 1668;
Methods 8081, 8082, 8121, 8151, 8280, and 8290; Methods TO-4a, TO-9a, and TO-lOa; and Method
23. Individual chlorinated organic compounds are also included in the target analyte list of the
following analytical methods: EPA Methods 601, 602, 604, 605, 608, 611, 612, 613, 615, 624, 625,
8021, 8081, 8082, 8121, 8151, 8260, 8270, and 8290.] Chlorinated organic compounds pose many of
the same complexities in terms of volume and diversity of the class of chemistries that EPA suggests
are raised by PFAS.
c. EPA Should Use a Scientifically Rigorous Approach to Listing PFAS
EPA should use a similarly scientifically rigorous approach to PFAS as it has for chlorinated organic
compounds. EPA has acknowledged that there are differences between, for example,
perfluorocarbons (PFCs) and PFAS generally, https://www.epa.gov/pfas/what-arepfcs-and-how-do-
they-relate-and-polyfluoroalkyl-substances-pfass. Both PFCs and PFAS molecules contain fluorine and
carbon atoms, but PFCs are "quite different from PFASs in significant respects..." Id. Despite these
significant differences, PFCs are included in EPA's proposed PFAS definition.
On September 16, 2021, EPA published the Multi-Industry Per- and Polyfluoroalkyl Substances (PFAS)
Study - 2021 Preliminary Report. That report included an entire section describing the many
significant differences between various PFAS. See EPA PFAS Study at 3-1 - 3-11. As EPA notes, "[t]he
thousands of chemicals that make up the PFAS family can be divided into two classes: nonpolymers
and polymers. Each class may contain subclasses, groups, and subgroups." Id. at 3-1. Figure 1 of the
EPA PFAS Study shows how EPA has divided the PFAS "family" into two classes (nonpolymers and
polymers), five subclasses, five groups, and ten subgroups. Id. at 3-2. EPA then identifies specific
substances that fall into each subclass, group, and subgroup, with a description of general chemical
structure. Id. at 3-5 - 3-6. EPA should consider these and other differences within the broad PFAS
group, just as it did with chlorinated organic compounds, and develop definitions based on
environmental, health, and safety properties with proven causal effects against stated target metrics.
Finally, 3M recognizes EPA's statement that "listing these three chemical groups on the Draft CCL 5
does not necessarily mean that EPA will make subsequent regulatory decisions for the entire group.
EPA will evaluate scientific data on the listed groups, subgroups, and individual contaminants included
in the group to inform any regulatory determinations for the group, subgroup, or individual
contaminants in the group." Id. at 37962. However, it is important for the scientific integrity of EPA's
future actions to apply consistent groupings across the Agency's analysis now at a foundational level.
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II. EPA Should Not Evaluate PFAS Differently Than Other Contaminants
Although EPA used a scientific screening process to identify nearly all substances it recommends for
inclusion on the draft CCL 5, PFAS are treated quite differently than other candidates considered.
PFAS as a group was a public nomination that should have been vetted based on the same scientific
standards EPA applied to screen for development of the PCCL. This includes EPA's application of the
new screening system to PFAS, but because there is no contaminant information sheet (CIS) for PFAS
provided in the supporting technical materials, it is unclear whether this important information was
taken into consideration.
The Proposed Rule describes in detail the screening process it used to identify substances for
inclusion on the PCCL:
EPA maintained the framework of screening chemicals to the PCCL based on their available toxicity
properties and occurrence data (USEPA, 2009b). To screen chemicals for the CCL 5, EPA developed a
transparent and reproducible scoring rubric and pointbased screening system. This pointbased
screening system is an improvement over the Toxicity Categories and Occurrence Hierarchies
developed for the CCL 3 (USEPA, 2009b) because it incorporates data from all the available data
elements identified for use in screening rather than relying on an individual data element that
indicates the highest toxicity or occurrence for a chemical.
Also:
There are also new data elements related to both health and occurrence endpoints that EPA included
in the CCL 5 screening process that were not available in a retrievable format or not used in previous
CCL cycles, including National Health and Nutrition Examination Survey (NHANES) biomonitoring data
and results from EPA's ToxCast in vitro screening assays. EPA designed the CCL 5 screening process to
accommodate quantitative, calculated, and descriptive types of data.
In addition to considering frequency of detections in drinking water, EPA assigned data elements to
chemicals including Reference Dose, no observed adverse effect level (NOAEL), lowest observed
adverse effect level (LOAEL), and LD50. EPA identified none of this information for PFAS, either
individually or as a group. Indeed, this kind of information is not currently available for every PFAS
and certainly not for the listed group as a whole.
For other substances, EPA's evaluation teams considered a range of data including occurrence in
water and health effects data as part of the preliminary screening process. The Proposed Rule states
that EPA "did not add publicly nominated groups like 'the top 200 most prescribed drugs in 2016 and
their parents and metabolites' to the PCCL 5 because health effects and occurrence data must be
linked to specific individual contaminants in order to be evaluated." Id. at 37969. EPA also states that
"[w]ithout available data regarding measured occurrence in water or relevant data provided by the
nominators, the two evaluation teams agreed that they could not determine whether these chemicals
were likely to present the greatest public health concern through drinking water exposure and
therefore should not advance further in the CCL 5 process." Id.
EPA did not apply this standard to PFAS. EPA did not link any health effects or occurrence data to
specific PFAS included in the listed group. The only occurrence data EPA identified related to PFAS
was specific to PFOA and PFOS, which are explicitly not included in the listing. Where occurrence data
was not available for substances other than PFAS, the substance was removed from the draft CCL.
EPA states "Data search efforts did not yield occurrence data for 13 publicly nominated chemicals that
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were lacking occurrence data in the CCL 5 Chemical Universe. As a result, these chemicals were not
evaluated for listing on the Draft CCL 5." Id. at 37960.
These inconsistencies in the screening and selection process for the CCL jeopardize the scientific
integrity of the tool. If EPA is proposing a risk-based program, as it appears to be based on the
description of the screening process, the decision to list materials would be supported by data on
these materials' potential risks. If the program is not risk-based but instead based on a precautionary
approach or external pressures, it is still vital that there be some framework through which EPA will
decide which chemicals to list. If the approach is precautionary, the potential costs and benefits of a
proposed listing must be explicit. No such information was provided for listing PFAS. EPA has not
identified any basis for treating PFAS differently other than there are many of them and therefore it is
challenging to evaluate them.
PFAS should not be evaluated differently than other substances. Using different standards, applying
screening criteria inconsistently, or requiring different or no technical support undermines the
integrity of the process and is inconsistent with past practice. It also undermines the future
precedential value of the process. EPA should identify a methodology for screening substances for
inclusion on the CCL and apply it to all substances consistently.
III. The Proposed Rule Lacks Technical Support for Listing PFAS as a Group
EPA has included almost no technical support for its decision to include PFAS on the draft CCL 5. [FN5:
One of the technical documents EPA lists as a document relied upon is not accessible on the
www.regulations.gov docket site (Identification of Novel Perfluoroalkyl Ether Carboxylic Acids
(PFECAs) and Sulfonic Acids (PFESAs) in Natural Waters Using Accurate Mass Time-of-Flight Mass
Spectrometry (TOFMS).] There is no CIS for PFAS as a group, or any specific PFAS, included in the
technical support information. EPA cites neither occurrence nor health effects information for PFAS in
the proposal or the technical support documents. Moreover, EPA did not cite any qualifying health
assessments for PFAS and there are no results for PFAS included in the Rapid Systemic Literature
Review Results ("RSR"). To the extent it relies on technical support for its PFAS listing, EPA either uses
surrogate indicators it ranked as least desirable in place of actual data for every category that it
considered in the screening process or relies on information related to substances it specifically
excluded from listing (PFOA and PFOS).
Although EPA explained that it did not conduct a health effects RSR for chemicals currently prioritized
by other agency processes (e.g., PFAS), it also did not include reasonably sufficient information in the
Federal Register notice or supporting documents to indicate the basis upon which it decided to list
PFAS as a chemical group. Combining multiple PFAS as a sum for risk assessment and/or assuming
equal potency for individual PFAS are not scientifically sound and there is no support for such a
practice.
a. There is No Technical Support for Listing PFAS as a Group
Even among just a handful of the thousands of PFAS captured by EPA's proposed definition, these
materials' distinct and widely varying properties mean there is no scientific basis for evaluating PFAS
as a monolith. Scialli et al. (2007) and Peters and Gonzalez (2011) independently evaluated the
scientific feasibility of combining perfluoroalkyl exposures for risk assessment based on the critical
concept of Toxic Equivalency Factors (TEFs), which was developed for dioxin-like compounds. Scialli et
al. (2007) reviewed similar same-species studies performed with different perfluoroalkyls and they
found large discordance in endpoints measured for PFOS, PFOA, PFBS, and PFDA. Peters and Gonzalez
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(2011) also concluded that perfluoroalkyl exposure should not be combined for risk assessment
purposes based on the following observations:
• lack of conclusive evidence demonstrating that a single receptor is required to mediate the
toxicities of perfluoroalkyl chemicals;
• the potential influence of species differences in the response to PPARa ligands that would
significantly limit this approach;
• inconsistent toxicities observed with different perfluoroalkyl chemicals; and
• a limited toxicological database for a number of perfluoroalkyls chemicals (e.g.,
perfluorinated sulfonamide polymers and perfluorinated sulfonamide-based phosphate
fluorosurfactants).
Rigorous, reliable scientific evidence indicates there is not a sound basis to treat thousands of PFAS as
a group. 3M welcomes the opportunity to continue to engage with EPA in rigorous, science-based
dialogue to determine how these materials potentially could be grouped in a scientifically sound way.
However, there is not currently any technical support in the Proposed Rule or supporting documents
that justify listing PFAS as a single group.
b. Assuming Equal Properties Among Individual PFAS is Not Scientifically
Supported
Available data demonstrate that there is a large spectrum of differences in the biological responses
observed in laboratory animals under toxicological study conditions for most perfluoroalkyls
evaluated. For example, the European Food Safety Authority (EFSA) recently applied equal toxicity
potencies to a group of selected PFAS (PFOA, PFOS, PFHxS, and PFNA). The actual data, however, are
inconsistent with that application. Qualitatively, it is true that these four perfluoroalkyls do have
longer serum elimination half-lives in humans, however, there are distinct quantitative differences for
the reported half-lives as well as in the categorical effects with animal data. Specific effects, such as
dose response outcomes included health conditions and mortality in toxicological animal studies, are
observed at largely different quantitative levels depending on the compounds and doses. The
proposed definition of PFAS includes gaseous, liquid, and solid compounds with variation in
properties such as volatility and water solubility. Therefore, it is scientifically inappropriate to assume
they all have the same effects.
IV. EPA Should Not Include Substances on the CCL 5 for Which There is Currently
No EPA Validated Testing Methodology
At this time, there is no testing methodology approved by EPA for the vast majority of substances
included in EPA's listing definition for PFAS. EPA Methods 537.1 and 533, both for drinking water, are
validated methods for 29 PFAS total. During the public comment period on the Proposed Rule, EPA
published draft Method 1633, "a single-laboratory validated method to test for 40 PFAS compounds
in wastewater, surface water, groundwater, soil, biosolids, landfill leachate, and fish tissue." [FN6: See
https://www.epa.gov/cwa-methods/cwa-analytical-methods-and-polyfluorinated-alkyl-substances-
pfas] Even the most current and innovative testing capabilities cannot test for more than
approximately 70 PFAS. Given the variety among PFAS substances, any evaluation of their occurrence
or potential health or environmental effects will vary depending on the specific PFAS under
consideration. It is also not scientifically appropriate to rely on total organic fluorine levels in
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environmental sampling as a proxy for PFAS that do not currently have an approved testing
methodology. EPA has appropriately recognized elsewhere that total organic fluorine "may not be
sensitive or specific enough to support decision making...." 86 Fed. Reg. at 13855. As EPA has noted,
total organic fluorine is broader even than PFAS and could capture other fluorine-containing
compounds.
There is no practical reason to list substances on the CCL 5 that cannot be tested. EPA should focus on
establishing testing methodology to understand occurrence, which can and should inform future
regulatory decisions. In the meantime, it should only list substances on the CCL 5 for which it has
validated testing methods. If EPA nonetheless proceeds with including substances on the CCL 5 that
have no validated test methods, 3M suggests the use of performance-based criteria and that method
validations be done for each PFAS in each environmental media (drinking water, wastewater, air, soil,
etc.).
3M appreciates the opportunity to share our input on this important topic with EPA as we seek to
work collaboratively to achieve our shared goal of regulations grounded in rigorous, reliable science.
The proposed CCL 5 provides an opportunity for this important exchange of ideas, and we welcome
the opportunity to engage further in this discussion.
Individual Response: Please see Discussion on PFAS. General Comments. Other Drinking Water
Programs, and Other EPA Programs. EPA acknowledges that PFAS, along with other groups of
contaminants listed on CCL 5, are priority contaminants and therefore were treated differently than
the individually listed contaminants. In the PFAS Strategic Roadmap, EPA also acknowledges its need
to evaluate a large number of PFAS for potential human health and ecological effects and that most
PFAS have limited or no toxicity data. To address this data gap, EPA is developing a national PFAS
testing strategy to deepen understanding of the impacts of categories of PFAS, including potential
hazards to human health and the environment. EPA will use the testing strategy to identify important
gaps in existing data and to select representative chemical(s) within identified categories as priorities
for additional studies. For more information please refer to EPA's National PFAS Testing Strategy
(USEPA, 2021a).
In response the commenters statement that EPA "should expand the definition of PFAS to include the
full array of fluorinated substances, including all HFCs, HFOs, and HCFOs." At this time, EPA is not
expanding the definition to include these substances. However, EPA is proposing its first rule under
the American Innovation and Manufacturing (AIM) Act of 2020 to phase down the production and
consumption of hydrofluorocarbons (HFCs), highly potent greenhouse gases commonly used in
refrigerators, air conditioners, and many other applications. The AIM Act, which was included in the
Consolidated Appropriations Act, 2021, provides EPA new authorities to address HFCs in three main
areas: phasing down the production and consumption of listed HFCs, maximizing reclamation and
minimizing releases (via air, water, or soil) of these HFCs and their substitutes in equipment (e.g.,
refrigerators and air conditioners), and facilitating the transition to next-generation technologies by
restricting the use of HFCs in particular sectors or subsectors.
Comment Excerpt from Commenter 79
September 17, 2021
Submitted via www.regulations.gov
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Comments Received on PFAS
Ms. Radhika Fox, Assistant Administrator
Office of Water, USEPA Headquarters William Jefferson Clinton Building 1200 Pennsylvania Avenue,
N. W.
Mail Code: 4101M
Washington, DC 20460
Re: EPA's Draft 5th Drinking Water Contaminant Candidate List [EPA-HQ-OW-2018- 0594; FRL-
7251-01-0W]
Dear Assistant Administrator Fox:
I appreciate the opportunity to comment on the EPA's Draft Fifth Drinking Water Contaminant
Candidate List (CCL5). I support the EPA's stated intention to investigate and, if supported by good
data and sound science, regulate the chemical class referred to as per- and polyfluoroalkyl substances
(PFAS) in drinking water. However, as the EPA considers such regulation, it must keep in mind the
ubiquity of PFAS chemicals in the environment and the inability to detect and quantify 99+% of the
class's constituents in drinking water, coupled with the diversity of the class, the uncertainty as to
their human toxicity, and the lack of data on the ability to remove all class members using existing
technology.
PFAS have followed that unfortunate trajectory of being discovered as having unique, beneficial
properties decades ago; used widely for numerous purposes without adequate consideration of
potential harmful effects; discovered that their use is accompanied by detrimental environmental and
health impacts; and attempting to address the problems long after the materials have been recklessly
released into the environment. Polychlorobiphenyls (PCBs) are the classic example of such a group,
yet PFAS has the potential for greater damage to public health and the environment. PFAS have no
business being in the environment or in drinking water, but it must be recognized that neither
drinking water consumers nor drinking water utilities put them there. Although I support efforts to
keep these chemicals out of drinking water, addressing the chemicals at first instance by seeking to
remove them from drinking water foists all costs on the innocent instead of those responsible for
putting them there and fails to stop these contaminants at their source. This is not merely an
environmental and public health issue, but also an environmental justice issue that must be
addressed.
I also note that the description used to define membership in PFAS (using classic Markush language) is
potentially ambiguous. As the notice states,
For the purposes of this document, the structural definition of PFAS includes per- and polyfluorinated
substances that structurally contain the unit R-(CF2)C(F)(R')R". Both the CF2 and CF moieties are
saturated carbons and none of the R groups (R, R' or R") can be hydrogen.
The potential ambiguity occurs when a given compound contains one portion that satisfies this
structural requirement but also contains another portion that does not. For example, the compound
commonly referred to as ADONA (Dodecafluoro-3H-4,8-dioxanonanoate, CAS Nos. 919005-14-4 or
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958445-44-8) has the chemical formula CF30CF2CF2CF20CHFCF2C00H (in protonated form). The
portion of the formula highlighted here in green would satisfy the structural definition of PFAS
provided by the EPA, but the portion in red would not. It would be helpful to clarify that the presence
of a portion not meeting the structural requirement would exclude the compound from the PFAS
class if one or more other portions do so.
Additionally, I believe that the definition being used is inadequate because it would omit several
compounds from the PFAS class that nevertheless should be considered along with the members of
that class. For example, this structural definition would not encompass the following compounds:
Acronym
PFMOAA
PMPA
PEPA
PF02HxA
PF030A
PF04DA
PF05DoDA
CAS No.
CF30CF2C00H 674-13-5
13140-29-9
Compound Molecular Formula
Perfluoro-2-methoxyacetic acid
Perfluoro-2-methoxypropanoic acid CF30CF(CF3)C00H
Perfluoro-2-ethoxypropanoic acid C2F50CF(CF3)C00H
Perfluoro (3,5-dioxahexanoic) acid
Perfluoro(3,5,7-trioxaoctanoic) acid
267239-61-2
39492-88-1
39492-89-2
CF3(OCF2)2COOH
CF3(OCF2)3COOH
Perfluoro(3,5,7,9-tetraoxadecanoic) acid CF3(OCF2)4COOH 39492-90-5
Perfluoro(3,5,7,9,ll- pentaoxadodecanoic) acid CF3(OCF2)5COOH
39492-91-6
As these compounds have been previously detected in the Cape Fear River in North Carolina, they
should not escape the same regulatory fate as any other PFAS compound. Putative Markush
descriptions to capture this group and other related compounds could be R-CF2-0-CF2-R' and RCF2-
O-CHF-R', wherein both the CF2 and CHF moieties are saturated carbons and none of the R groups (R
or R') can be hydrogen.
A more significant concern is the near impossibility of actually detecting and quantifying the
occurrence of 99+% of the members of the putative PFAS class in raw and finished drinking water. The
problem with not being able to detect virtually all members of the PFAS group is that no one would be
able to say with any certainty that their drinking water contained an acceptable amount of PFAS
unless it had testing data to back up such a claim. The problem can be explained using the notable
example of the compound known as 6:2 fluorotelomer alcohol (6:2 FTOH, CAS # 64742-7). In 2020,
the U.S. Food and Drug Administration (FDA) published findings from a postmarket scientific review
and analysis of data from rodent studies on 6:2 FTOH, which raised questions about the potential
human health risks from dietary exposure resulting from exposure to food-packaging material that
contained 6:2 FTOH, which the FDA had authorized. Shortly thereafter, the FDA announced that it had
convinced several manufacturers to voluntarily phase out some food-packaging materials that are
referred to as side-chain polymers, where the side chains were 6:2 FTOH and had a tendency to
escape the polymer and migrate to the food. See https://www.fda.gov/food/cfsan-constituent-
updates/fda-announces-voluntary-phase-out-industry-certain-pfas-used-food-packaging. However,
those materials were only one category of food-packaging materials that may contain 6:2 FTOH. Two
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other categories of food-packaging materials, polyfluoroalkyl phosphate monoesters (monoPAPs) and
polyfluoroalkyl phosphate diesters (diPAPs), are widely used food contact materials that imbue water
and oil repellency for surfaces to which they have been applied. See Birgit Geueke, Food Packaging
Forum, July 2016, https://www.foodpackagingforum.org/fpf-2016/wp-
content/uploads/2016/07/FPF_Dossierl0_PFASs.pdf. Both monoPAPs and diPAPs are known to have
been manufactured using 6:2 FTOH and would serve as potential sources of 6:2 FTOH in a similar
manner as the side-chain polymers that FDA convinced some manufacturers to phase out. This
background is provided because even though it is undisputed that 6:2 FTOH poses potential health
risks to humans, there is no current EPA-approved analytical method available to test drinking water
for 6:2 FTOH. In fact, there are no such approved analytical methods to test drinking water for
monoPAPs, diPAPs, or even the 6:2 FTOH-containing side-chain polymers that FDA was quick to push
to be phased out. Part of the reason that 6:2 FTOH is not included in drinking water methods is that
the class of fluorotelomer alcohols are notoriously difficult to detect using the analytical technology
and equipment employed in EPA-approved methods. See https://well-
labs.com/docs/pfc_reference_handling_guide.pdf, page 14. Yet no such difficulty exists for detecting
6:2 FTOH-containing diPAPs. See Timothy L. Coggan et. al, "A single analytical method for the
determination of 53 legacy and emerging per- and polyfluoroalkyl substances (PFAS) in aqueous
matrices," Analytical and Bioanalytical Chemistry (2019) 411:3507-3520,
https://doi.org/10.1007/s00216-019-01829-8.
Even if these compounds existed in drinking water, it is unclear how effective existing treatment
technologies would be to remove them. To be sure, monoPAPs and diPAPs would likely be removed
by granular activated carbon (GAC) and/or anionic ion exchange resins. But 6:2 FTOH will remain
nonionic in drinking water, whether introduced on its own or shed from a captured polymer or PAP,
and no one knows for how long GAC (or less likely ion exchange resins) will be effective in removing it
from drinking water, assuming any efficacy at all.
I've described one single PFAS compound, well known and under current study, as well as two
subcategories of PFAS that have been used for years in food packaging with the FDA's blessing, that
drinking water suppliers would have no practical ability to detect in their water even if they wanted
to. And there are thousands of other compounds in the PFAS family, none of which have a chance of
being detected. This brings me to my greatest concern of all: any attempt to regulate PFAS as a
uniform, monolithic group will inevitably lead to the creation of a false sense of security in the public,
because no water provider can honestly say that PFAS in its drinking water does not exceed a given
value when 99+% of PFAS compounds cannot be detected or quantified using existing analytical
methods.
I wish dealing with PFAS compounds were as simple as EPA's proposal for treating them as a class
sounds. Such an approach made sense for PCBs, which are highly similar in terms of structure and
properties. But that it is not the case for PFAS compounds, which are extremely diverse in terms of
structure, properties, occurrence, and risk to public health. PFAS compounds do pose risks to public
health, and they must be studied and dealt with. But attempting to take shortcuts without putting in
the time and effort to properly assess them is not the answer.
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For sure, some subgroups of PFAS can and should be assessed together, but even that has limits. For
example, EPA developed chronic reference doses (RfDs) for perfluorooctanesulfonic acid (PFOS) and
perfluorobutanesulfonic acid (PFBS), both of which are within the perfluoroalkanesulfonic acid (PFSA)
subgroup. However, PFBS' RfD was 150% higher than PFOS' RfD, which reflected significant lower
chronic toxicity. If EPA can extensively study two different compounds that are squarely within the
PFAS family—and the PFSA subgroup—and decide that one requires regulation in drinking water and
the other does not, how could it ever be reasonable to attempt to assess the entire PFAS class in
gross? If the EPA decides to regulate all PFAS (except PFOA and PFOS, which it has excluded from
consideration here) as a class, does that mean that the EPA erred in concluding that regulating PFBS
was unnecessary?
Perhaps it may turn out that many or even most PFAS require regulation in drinking water. The EPA
has already concluded that such regulation is unnecessary for PFBS, and others will not require
regulation. But the EPA, Congress, and the citizens of the United States need to make this a priority
and spend the time and money needed to reach the reasonable, defensible, and just conclusion for
PFAS compounds. It should and must be done, but it must be done with hard work, not by taking the
shortcut of lumping all PFAS compounds together because it is simpler or easier.
Thank you for considering my comments.
Very truly yours,
Paul T. Nyffeler, Ph.D.
Individual Response: Please see Discussion on PFAS. General Comments, and Other Drinking Water
Programs. EPA agrees with the commenters statement that PFAS are a diverse group of chemicals. As
EPA moves to the following stages of the SDWA framework, it will follow a robust process and will
provide proper assessment to individual PFAS and PFAS as a group.
Comment Excerpt from Commenter 80
Terrence Thrweatt Jr.
University of Baltimore
September 17, 2021
Per- and Polyfluoroalkyl (PFAs) are Harmful and Should be Banned
I am writing this comment in support of adding the per- and polyfluoroalkyl (PFAs) to the Candidate
Contaminant List (CCL) for Public Water Suppliers (PWS) to monitor and report any level of
contamination, as well as to comply with any initiated regulations at the local or state level. PFAs are
toxic by-products which are commonly used chemicals in the production process of non-stick
materials. They have been used in non-stick cookware (i.e. pots and pans), food packaging items, and
beauty and cosmetic items . The side effects of PFAS include low infant birth weights, adverse effects
on the immune system, cancer (for PFOA), and thyroid hormone disruption (for PFOS). Unfortunately,
PFAs remain on a product through its full production and even into the disposal. Today, due to its
unescapable use in manufacturing and industrial supply chains, nearly every American can find
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evidence of PFAs in their bloodstream . Despite PFAs imposing a public health risk, little is being done
by our law-making bodies to curb the consequences.
The CCL is a list of contaminants which currently can be found in rural, urban, and suburban water
supply systems. The listed substances are known to be pervasive enough that at least trace amounts
are expected to be found in even the most properly maintained public municipalities. Unmaintained
or outdated water systems are at an equally, or increased, pronounced risk of testing positive for the
impurities. In fact, a study of 300 military bases demonstrated that PFAs were prominent in the
drinking water of the majority of the studied sites. This is unacceptable. Due to their level of toxicity
and producible harm posed against humanity, I believe that PFAs have earned their place on the CCL
list.
Currently, only one state, Maine, has banned products containing PFAS . The people of Maine took
this necessary step to protect their citizens from PFAS-related harms. We must make this a national
priority. There is already legislation before Congress to address this deadly compound. The EPA can
take the first step. By acting within its power, it can advance PFAs on the CCL. This will lead to
regulation of PFAs in drinking water. It is my profound hope that this product will be more strictly
regulated to prevent further harm.
Individual Response: Please see Discussion on PFAS, General Comments, Other Drinking Water
Programs, and Other EPA Programs.
Comment Excerpt from Commenter 81
Gregory M. Bowser, President & CEO
COMMENTS OF THE LOUISIANA CHEMICAL ASSOCIATION on EPA Draft Drinking Water Contaminant
Candidate List—5 86 Federal Register 37948 July 19, 2021 (Proposed Rule) Docket ID Number EPA-
HQ-OW-2018-0594
INTRODUCTION
The Louisiana Chemical Association ("LCA") appreciates the opportunity to comment on the U.S.
Environmental Protection Agency's ("EPA") Notice of Drinking Water Contaminant Candidate List 5
("CCL 5") Draft under the Safe Drinking Water Act (SDWA), Docket ID No. EPA-HQ-OW-2018-0594,
published in the Federal Register on July 29, 2021, at 86 Federal Register 37948.
LCA is a nonprofit Louisiana corporation, composed of sixty-three (63) members with over one
hundred (100) chemical manufacturing plant sites in Louisiana. LCA was formed in 1959 to promote a
positive business climate for chemical manufacturing that ensures long-term economic growth for its
member companies. LCA members are committed to excellence in safety, health, security and
environmental performance, and to protecting our employees and surrounding communities.
LCA member companies have managed or have used per- and polyfluoroalkyl substances ("PFAS") in a
wide range of applications. PFAS are used in almost all industries and are found in many consumer
products. LCA members are therefore directly affected by this Draft CCL 5, as it relates to the
inclusion of PFAS as a chemical group. LCA supports the development of drinking water standards that
protect public health and reflect the best available scientific evidence. However, LCA opposes
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regulating PFAS as a class and submits these comments on behalf of its affected members.
COMMENTS
1. Background
Section 1412(b)(l)(B)(i) of the Safe Drinking Water Act ("SDWA"), as amended in 1996, requires the
EPA to publish every five years a list of drinking water contaminants which are not subject to any
proposed or promulgated National Primary Drinking Water Regulations ("NPDWR"), are known or
anticipated to occur in public water systems ("PWS"), and may require regulation under the SDWA.
This list is known as the Contaminant Candidate List, or CCL.
The SDWA directs the EPA to consider health effects and occurrence information for unregulated
contaminants to identify those that present the greatest public health concern related to exposure
from drinking water. EPA uses this list of unregulated contaminants to help identify priority
contaminants for regulatory decision making and to prioritize research and data collection efforts.
On July 19, 2021, EPA published the fifth candidate list. The Draft CCL 5 includes 66 chemicals, three
chemical groups (PFAS, cyanotoxins, and disinfection byproducts) and 12 microbial contaminants. EPA
requested comments on the Draft CCL 5 and on improvements implemented in the CCL 5 process for
consideration in developing future CCLs. With these comments, LCA focuses on the inclusion of PFAS
as a chemical group.
2. The diverse chemistries of PFAS chemicals make including them in the CCL 5 and regulating
them as a group inappropriate.
According to the Draft CCL 5, "[o]ver 4,000 PFAS have been manufactured and used globally since the
1940s, which would make listing PFAS individually on the Draft CCL 5 difficult and challenging." [FN1:
Draft CC 5, pg. 37962 (citations omitted).] Accordingly, EPA is proposing to list PFAS as a group
inclusive of any PFAS, except the two that are already in the regulatory process - perfluorooctanoic
acid (PFOA) and perfluorooctane sulfonic acid (PFOS).
PFAS as a class represent differing fundamental physical, chemical, and biological properties.
According to the EPA, "approximately 600 PFAS are manufactured (including imported) and/or used in
the United States." [FN2: Addition of Certain Per- and Polyfluoroalkyl Substances; Community Right-
to-Know Toxic Chemical Release Reporting, 84 FR 66369 (Dec. 4, 2019).] Among these 600 are
substances in the solid (e.g., fluoropolymers), liquid (e.g., fluorotelomer alcohols), and gaseous (e.g.,
hydrofluorocarbon refrigerants) forms. [FN3: American Chemistry Council, "PFAS Grouping: An
Emerging Scientific Consensus" (collecting sources) (available at:
https://www.americanchemistry.com/chemistry-in-america/chemistries/fluorotechnology-per-
andpolyfluoroalkyl-substances-pfas/resources/pfas-grouping-an-emerging-scientific-consensus) (last
visited Sept. 15, 2021).] These distinct physical and chemical properties demonstrate how varied PFAS
are and why a simple grouping approach to risk is inadequate.
EPA's reasoning that the sheer number of PFAS makes classification on a chemical or sub-class basis
impossible is a false premise. Rather, because the number of chemicals classified as PFAS is so great,
and the chemistries vary so vastly, it is scientifically accurate and appropriate to not regulate them as
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a class. EPA has already proven the Agency is capable of analyzing PFAS on a chemical basis through
its regulation of PFOA and PFOS. As such, EPA should not include PFAS as a class in the final CCL 5.
3. The inclusion of PFAS as a class without performing full screening or classification
demonstrates the inadequacy of regulating PFAS as a single class.
EPA describes its decision process for including chemicals briefly in the Draft CCL 5 Notice and more
fully in the Technical Support Document. [FN4: See Technical Support Document for the Draft Fifth
Contaminant Candidate List (CCL 5) - Chemical Contaminants.] As noted in the Technical Support
Document, EPA performs three steps: (1) assessing and identifying data sources; (2) screening; and (3)
classification. Within each of those steps, EPA performs multiple layers of analysis. For example,
during the screening step, EPA develops a scoring rubric and selects the top 250 chemicals before
considering publicly nominated chemicals and chemicals that should be excluded. For CCL 5, this
process identified 275 chemicals. [FN5: Notably, 13 individual PFAS were included in the identified
275 chemicals. But instead of analyzing these 13, EPA excluded them and opted for including PFAS as
a class. Id. at pg. 42 of 101 and Appendix D.] The selected chemicals are then further classified using
supplemental data, calculated data elements (such as health reference levels, screening levels, final
hazard quotients, and attribute scores), and contaminant information sheets. Because EPA included
PFAS as a collective group in response to public nominations, none of the PFAS chemicals were fully
analyzed under EPA's CCL development framework for chemicals.
None of the individual PFAS chemicals were fully analyzed through the screening system or subject to
the classification process. Rather, EPA included PFAS as a collective group based both on public
nominations and because it would have been "difficult and challenging." Notably, EPA did not state
that it would have been unduly burdensome or against scientific data to have analyzed one or more
PFAS chemicals or groups of chemicals. Rather, EPA noted that:
Including the broad group of PFAS on the Draft CCL 5 demonstrates the agency's commitment to
prioritizing and building a strong foundation of science on PFAS while working to harmonize multiple
authorities to address the impacts of PFAS on public health and the environment.
It was inappropriate for EPA to base inclusion of the entire class of PFAS on public nominations rather
than on the scientific method discussed above. Although SWDA section 1412 does not proscribe a
specific method for including a chemical on the CCL, EPA should follow its own method in determining
whether individual PFAS "are known or anticipated to occur in public water systems, and which may
require regulation" such that one or more should be included on the CCL 5. [FN6: 42 U.S.C.A. § 300g-
1.]
4. EPA should analyze inclusion of a PFAS on a chemical basis or at least on a smaller subclass
basis.
As noted above, the varying chemistries of PFAS makes it inappropriate to cast the entire universe of
chemicals a single group. EPA should perform the same three step analysis on relevant PFAS
chemicals to determine potential inclusion in the CCL 5. To reduce the regulatory burden, EPA may
find it appropriate to group of some substances within the broad PFAS class based on similar physical,
chemical, and biological properties. LCA would support this more nuanced approach instead of
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inappropriately grouping all PFAS as a class. For example, see Buck, R.C., Korzeniowski, S.H., Laganis,
E. and Adamsky, F. (2021), Identification and classification of commercially relevant per- and poly-
fluoroalkyl substances (PFAS). Integr Environ Assess Manag, 17: 1045-1055 (available at;
https://setac.onlinelibrary.wiley.com/doi/10.1002/ieam.4450) (last visited Sept. 15, 2021). LCA does
not comment on the specific way in which the study sub-divided PFAS chemicals or whether all PFAS
could be subjected to subdivision. In fact, the grouping of substances under a single standard is
justified only when the substances are believed to cause adverse health effects by the same
mechanism. Rather, the LCA suggests that EPA should have considered this type of approach instead
of inappropriately grouping all PFAS as a class.
LCA appreciates the opportunity to submit comments on this rulemaking.
Tokesha Collins Wright
LCA Vice President of Environmental
Affairs and General Counsel
Individual Response: Please see Discussion on PFAS. General Comments, and Other Drinking Water
Programs.
Comment Excerpt from Commenter 83
Submitted via Regulations.gov
September 17, 2021
Administrator Michael Regan
U.S. Environmental Protection Agency 1200 Pennsylvania Ave, N.W.
Washington, DC 20460-0001
Re: Docket Nos. EPA-HQ-OPPT-2020-0549, EPA-HQ-OW-2018-0594; Toxic Substances Control Act
Reporting and Recordkeeping Requirements for Perfluoroalkyl and Polyfluoroalkyl Substances, and
Drinking Water
Contaminant Candidate List 5-Draft
Dear Administrator Regan,
The undersigned are scientists with expertise in per- and polyfluoroalkyl substances ("PFAS")
chemistry and toxicity. We are dedicated to better understanding the use and impacts of PFAS and
deriving solutions to reduce serious adverse human and environmental health outcomes as a result of
PFAS exposure.
We submit these comments in response to two recent actions proposed by the United States
Environmental Protection Agency ("EPA" or the "Agency"): (1) a proposed rule under section 8(a)(7)
of the Toxic Substances Control Act ("TSCA"), [FN1: TSCA Section 8(a)(7) Reporting and Recordkeeping
Requirements for Perfluoroalkyl and Polyfluoroalkyl Substances, 86 Fed. Reg. 33,926 (proposed June
28, 2021) (to be codified at 40 C.F.R. pt. 705).] which would require reporting and recordkeeping for
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PFAS chemicals manufactured in (including imported into) the United States since 2011, and (2) a
listing of PFAS on the Safe Drinking Water Act ("SDWA") Draft Contaminant Candidate List 5 ("Draft
CCL 5"), which is the first step in the screening and evaluation of chemicals that may warrant future
regulation under the SDWA. [FN2: Drinking Water Contaminant Candidate List 5 - Draft, 86 Fed. Reg.
37,948 (proposed July 19, 2021) (to be codified at 40 C.F.R. pt. 141).] We support EPA's efforts to
acquire detailed information on PFAS and its initial steps toward greater regulation of PFAS in drinking
water.
One of the strengths of both proposals is that they apply a class-based approach to addressing PFAS.
However, in both proposed agency actions, EPA employs a "working definition" [FN3: TSCA Section
8(a) Reporting, 86 Fed Reg. at 33,929; Drinking Water Contaminant Candidate List 5, 86 Fed. Reg. at
37,962.] of PFAS that is inconsistent with the commonly accepted definition recently adopted by the
Organisation for Economic Co-operation and Development ("OECD") [FN4: OECD. (2021). Reconciling
Terminology of the Universe of Per- and Polyfluoroalkyl Substances: Recommendations and Practical
Guidance, https://www.oecd.org/chemicalsafety/portal-perfluorinated-chemicals/terminology-per-
andpolyfluoroalkyl-substances.pdf.] and used in most U.S. legislation. This overly narrow definition
would exclude many PFAS of known concern, undercutting the benefits of the Agency's actions. [FN5:
Working definition from both TSCA and SDWA proposed agency actions: "[T]he structural definition of
PFAS includes per- and polyfluorinated substances that structurally contain the unit R-(CF2)-
C(F)(R')R". Both the CF2 and CF moieties are saturated carbons and none of the R groups (R, R' or R")
can be hydrogen." TSCA Section 8(a) Reporting, 86 Fed Reg. at 33,929; Drinking Water Contaminant
Candidate List 5, 86 Fed. Reg. at 37,962.] For the reasons set forth below, we urge EPA to instead use
the PFAS definition recently adopted by the OECD ("OECD definition"), which is scientifically sound
and consistent with definitions that have been included in federal and state laws regulating PFAS.
I. EPA's Definition of PFAS in the Proposed TSCA Section 8(a)(7) Rule and SDWA Draft CCL 5 Does Not
Include All PFAS.
PFAS as a class pose dangers to human and environmental health. Due to the presence of the highly
stable, fully fluorinated carbon moieties, PFAS are either extremely resistant to environmental
degradation—or transform into other highly persistent PFAS. Studies have shown that some PFAS
take thousands of years to fully degrade. Their highly persistent nature further enables PFAS to
accumulate in the environment, including in water, sediment, soil, and plants. [FN6: Kwiatkowski, C.
F., Andrews, D. Q., Birnbaum, L. S., Bruton, T. A., DeWitt, J. C., Knappe, D. R. U., Maffini, M. V., Miller,
M. F., Pelch, K. E., Reade, A. Soehl, A., Trier, X., Venier, M., Wagner, C. C., Wang, Z., & Blum, A. (2020).
Scientific Basis for Managing PFAS as a Chemical Class. Environmental Science & Technology Letters,
7(8), 523-543. https://doi.org/10.1021/acs.estlett.0c00255.] Multiple lines of scientific evidence
suggest that many PFAS can contribute to a wide range of adverse health outcomes, including cancer,
endocrine disruption, reproductive harm, and immunosuppression. [FN7: Pelch, K. E., Reade, A.,
Kwiatkowski, C., Schultz, K., Varshavsky, J., Cavalier, H., MercedNieves, F., & Wolffe, T. (2021, June 7).
PFAS Health Database: A Systematic Evidence Map. OSF. Retrieved September 15, 2021, from
https://osf.io/f9upx/; Kwiatkowski et al., supra note 6.]
Due to these shared characteristics, many of us co-authored a scientific review of the studied human
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and environmental health harms posed by PFAS in which we recommend wide adoption of a "class-
based approach to managing the human and environmental risks associated with all PFAS, including
polymers." [FN8: Kwiatkowski et al., supra note 6, at 537.] When regulatory agencies use a class-
based approach to regulate and/or gather data on PFAS, they should use a consistent and
comprehensive definition of PFAS to ensure that they gather information on all PFAS and avoid
missing key data on unknown or newer PFAS, as well as PFAS breakdown- or by-products. EPA's PFAS
definition used in both the TSCA section 8(a)(7) proposed rule and the proposed SDWA Draft CCL 5
listing, copied below, is scientifically unsupported, does not include all PFAS, and denies the Agency
critical information about PFAS:
[T]he structural definition of PFAS includes per- and polyfluorinated substances that structurally
contain the unit R-(CF2)-C(F)(R')R". Both the CF2 and CF moieties are saturated carbons and none of
the R groups (R, R' or R") can be hydrogen. [FN9: TSCA Section 8(a) Reporting, 86 Fed Reg. at 33,929;
Drinking Water Contaminant Candidate List 5, 86 Fed. Reg. at 37,962.]
EPA did not identify any scientific support for this definition in the TSCA section 8(a)(7) proposed rule,
and the only support cited in the proposed SDWA Draft CCL 5 listing was a cite back to the TSCA
section 8(a)(7) proposed rule.
It is particularly concerning that EPA's definition excludes many high production volume PFAS due to
its unduly narrow requirement for the presence of at least two adjacent fluorinated carbons. For
example, polyvinylidene fluoride ("PVDF"), a fluoropolymer that EPA has previously identified as a
PFAS [FN10: EPA. (2018, June 1). EPA Activities on Per- and Polyfluoroalkyl Substances (PFAS)
[PowerPoint slides],
https://yosemite.epa.gov/sab/sabproduct.nsf/708FDD305E55DC7E8525829C005F9EB4/$File/P
FAS+Presentation+SAB.pdf; Phelps, L.P. (2020, August 4). Understanding Per-and Polyfluoroalkyl
Substances (PFAS) in Air [PowerPoint slides], EPA.
https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=541095&Lab=CEMM] and
that is widely used to line plastic shipping containers, [FN11: Currently, PVDF is not reportable under
the Toxics Release Inventory under the Emergency Planning and Community Right-to-Know Act)] does
not meet EPA's definition due to its alternating fully fluorinated carbon structure.
EPA's definition also excludes other high production volume fluorinated chemicals, such as many
hydrofluorocarbon ("HFC") and hydrofluoroolefin ("HFO") refrigerant compounds, even though they
have been categorized as PFAS by at least five European countries. [FN12: European Chemicals
Agency, (n.d.). Registry of restriction intentions until outcome. Retrieved September
15,2021,fromhttps://echa.europa.eu/de/registry-of-restriction-
intentions//dislist/details/0b0236el8663449b.] This concern is compounded by the fact that the
exclusion of HFCs and HFOs from the definition makes it harder (if not impossible) to track their
environmental breakdown products, particularly those that are PFAS themselves and also fall outside
of the definition. For example, trifluoroacetic acid ("TFA") is a common HFC and HFO degradation
product that poses risk to human and ecological receptors. [FN13: Several of us have co-authored a
rebuttal to industry comments in which we highlighted health concerns posed by TFA, and we refer
readers to that rebuttal for the details of these concerns: Kwiatkowski, C. F., Andrews, D. Q.,
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Birnbaum, L. S., Bruton, T. A., DeWitt, J. C., Knappe, D. R. U., Maffini, M. V., Miller, M. F., Pelch, K. E.,
Reade, A. Soehl, A., Trier, X., Venier, M., Wagner, C. C., Wang, Z., & Blum, A. (2021). Response to
"Comment on Scientific Basis for Managing PFAS as a Chemical Class". Environmental Science &
Technology Letters 8(2), 195- 197. https://doi.org/10.1021/acs.estlett.lc00049.] and has been widely
recognized as a PFAS by the California Department of Toxic Substances Control and others, [FN14:
Safer Consumer Products, Department of Toxic Substances Control, & California Environmental
Protection Agency. (2019). Product - Chemical Profile for Treatments Containing Perfluoroalkyl and
Polyfluoroalkyl Substances for Use on Converted Textiles or Leathers, https://dtsc.ca.gov/wp-
content/uploads/sites/31/2019/ll/Product-Chemical-Profile-forTreatments-with-PFASs.pdf.] but it
falls outside of EPA's definition because it only possesses one fully fluorinated carbon. Like other
PFAS, TFA is highly persistent and mobile in the environment, and has also been linked to adverse
health outcomes like skin and eye damage and harm to aquatic life. [FN15: Kwiatkowski et al., supra
note 13.] Without accurate and robust reporting and recordkeeping of HFCs and HFOs, accurate
environmental tracking of PFAS breakdown products like TFA is not possible.
In addition, EPA's overly narrow definition creates opportunity and incentive for the chemical industry
to evade future regulatory requirements by manufacturing chemicals that possess the characteristics
associated with PFAS but fall outside of EPA's narrow definition. DuPont, one of the leading
manufacturers of PFAS in the United States, has been studying such compounds for nearly a decade.
[FN16: Peng, S., & Hung, M. (2012). Fluorinated sulfonate surfactants. Journal of Fluorine Chemistry
133, 77-85. https://doi.Org/10.1016/j.jfluchem.2011.10.007; Coope, T., Moloy, K., Yake, A., Petrov, V.,
Taylor, C., Hung, M., & Peng, S. (2014). Fluorinated sulfamido amphoteric surfactants. Journal of
Fluorine Chemistry 161, 41-50. https://doi.Org/10.1016/j.jfluchem.2014.01.022.]
The chemical industry has a long history of tweaking PFAS chemistry to evade regulation, including
the recent manufacturing shift from long-chain PFAS (like PFOA [FN17: PFOA is an abbreviation for
perfluorooctanoic acid.] and PFOS [FN18: PFOS is an abbreviation for perfluorooctanesulfonic acid.])
to shorter-chain "replacement" PFAS that were erroneously assumed to be less problematic and now
pose widespread environmental contamination issues, threatening human and ecological health.
[FN19: Sun, M., Arevalo, E., Strynar, M., Lindstrom, A., Richardson, M., Kearns, B., Pickett, A., Smith,
C., & Knappe, D. R. U. (2016). Legacy and Emerging Perfluoroalkyl Substances Are Important Drinking
Water Contaminants in the Cape Fear River Watershed Of North Carolina. Environmental Science &
Technology Letters 3(12), 415-419. https://doi.org/10.1021/acs.estlett.6b00398; Zhang, X., Lohmann,
R., Dassuncao, C., Hu, X. C., Weber, A. K., Vecitis, C. D., & Sunderland, E. M. (2016). Source Attribution
of Poly- and Perfluoroalkyl Substances (PFASs) in Surface Waters from Rhode Island and the New York
Metropolitan Area. Environmental Science & Technology Letters 3(9), 316-321.
https://doi.org/10.1021/acs.estlett.6b00255.]
II. EPA Should Adopt the OECD Definition of PFAS and Use this Definition in All EPA Rulemakings.
Rather than use the PFAS definition in the proposed TSCA and SDWA actions, we recommend that
EPA adopt the PFAS definition recently published by OECD, in which PFAS are defined as:
fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon atom
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(without any H/CI/Br/l atom attached to it). [FN20: OECD, supra note 4, at 23.]
As stated in the report supporting this definition, "the intention of the revision of the PFAS definition
is not to expand the PFAS universe, but to comprehensively reflect it. More concretely, the rationale
behind the revision is to have a general PFAS definition that is coherent and consistent across
compounds from the chemical structure point of view and is easily implementable for distinguishing
between PFASs and non-PFASs, also by non-experts." [FN21: Id. at 23.] The OECD definition is
scientifically sound and comprehensive; indeed, EPA scientists were members of the OECD group that
prepared this definition. [FN22: Id. at 5.]
The OECD definition offers several benefits over the EPA definition, as detailed below.
First, the OECD definition covers all fluorinated chemicals that share common characteristics of PFAS,
including persistence in the environment. Applying this definition across all EPA rulemakings in a
uniform and consistent manner will help to avoid confusion about which chemicals are considered
PFAS, and it will eliminate potential loopholes that incentivize the production of chemicals that fall
outside of regulatory definitions but that still possess physicochemical characteristics of PFAS and
behave like PFAS in the environment.
Second, using the broader OECD definition in the context of regulations that require submission of
information will expand the data EPA receives about use of, and exposures to, PFAS in the United
States. EPA's Comptox Database now indicates that there are over 9,000 PFAS, [FN23: EPA. (n.d.).
PFAS Master List of PFAS Substances (Version 2). Retrieved September 15, 2021, from
https://comptox.epa.gov/dashboard/chemical_lists/pfasmaster.] and only 175 of these are subject to
recordkeeping and reporting requirements under the Toxics Release Inventory; [FN24: EPA. (2021).
Chemicals Added to the Toxics Release Inventory Pursuant to Section 7321 of the National Defense
Authorization Act. https://www.epa.gov/sites/default/files/202101/documents/tri_non-
cbi_pfas_list_l_8_2021_final.pdf.] PVDF and HFCs are not among the 175 PFAS subject to these
reporting requirements. Adopting OECD's PFAS definition in both the TSCA and SDWA proposed
agency actions would enable information gathering for PFAS (like PVDF and HFCs) that currently fall
through regulatory cracks and could pose widespread exposure risks to humans.
Third, several federal and state laws have already employed definitions of PFAS that are consistent
with the OECD definition. For example, the National Defense Authorization Act for Fiscal Year 2020
defined PFAS as "perfluoroalkyl and polyfluoroalkyl substances that are manmade chemicals with at
least one fully fluorinated carbon atom." [FN25: National Defense Authorization Act for Fiscal Year
2020, Pub. L. No. 116-92, § 332(c)(3), 133 Stat. 1198, 1314 (2019).] Since 2019, eight states have
passed laws using similar, broad definitions of PFAS that are consistent with OECD's, including
California, [FN26: S. 1044, 2019 Leg., Reg. Sess. (Cal. 2020).] Colorado, [FN27: H.R. 19-1279, 72nd
Gen. Assemb., Reg. Sess. (Colo. 2019).] Maine, [FN28: H.R. 1043, 129th Leg., Reg. Sess. (Me. 2019).]
Vermont, [FN29: S. 20, 2021 Gen. Assemb., Reg. Sess. (Vt. 2021).] and Washington. [FN30: S. 5135,
66th Leg., Reg. Sess. (Wash. 2019).] It would create needless confusion if EPA's new regulatory actions
adopted different definitions of PFAS than those already in place in federal and state laws.
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III. Conclusion
For the reasons set forth above, EPA should apply the OECD definition in all PFAS-related actions the
Agency takes across programs, including in the proposed agency actions under TSCA and SDWA
discussed here. The TSCA section 8(a)(7) proposed rule presents an important opportunity for EPA to
obtain much-needed information about all PFAS in commerce in the United States over the last
decade. And the SDWA Draft CCL 5 listing is a critical first step toward regulating PFAS in drinking
water. For these actions to be as consequential as possible, we strongly urge EPA to consistently use a
definition of PFAS that is comprehensive and scientifically sound, such as the OECD definition. If EPA
finalizes the TSCA section 8(a)(7) rule with the narrower definition it proposed, it will deny the
Agency—and the public—much needed information about PFAS, and it will create inconsistencies
with federal and state laws that are already in place. Moreover, a narrower definition of PFAS in the
SDWA Draft CCL 5 listing will limit EPA's ability to adopt primary drinking water regulations for PFAS in
the future, undermining the Agency's promise of ensuring safe drinking water for all. Accordingly, we
urge EPA to adopt the scientifically supported OECD definition of PFAS in all of its rulemakings
pertaining to PFAS across programs.
If you have any questions about these comments, please contact Rashmi Joglekar, Earthjustice, at
rjoglekar@earthjustice.org.
Respectfully submitted,
David Andrews, PhD
Senior Scientist, Environmental Working Group
Linda S. Birnbaum, PhD
Scientist Emeritus and Former Director, NIEHS and NTP
Scholar in Residence, Nicholas School of the Environment, Duke University
Alan Ducatman, MD, MS
Professor Emeritus, School of Public Health, West Virginia University
Philippe Grandjean, MD
Adjunct Professor of Environmental Health, Harvard T. H. Chan School of Public Health, Harvard
University
Rashmi Joglekar, PhD
Staff Scientist, Earthjustice
Detlef Knappe, PhD
S.James Ellen Distinguished Professor,
Dept. of Civil, Construction, and Environmental Engineering, North Carolina State University
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Carol Kwiatkowski, PhD
Science and Policy Senior Associate, Green Science Policy Institute
Rainer Lohmann, PhD
Professor of Oceanography and Director of the URI SRP Center on PFAS, Graduate School of
Oceanography, University of Rhode Island
Sonya Lunder, MPH
Senior Toxics Policy Advisor, Sierra Club
Katherine Pelch, PhD
Independent Scientist
Hannah L. Ray, PhD
Science and Policy Associate, Green Science Policy Institute
Anna Reade, PhD
Staff Scientist, People & Communities Program, Natural Resources Defense Council
Erika Schreder, MS
Science Director, Toxic Free Future
Individual Response: Please see Discussion on PFAS, General Comments, Other Drinking Water
Programs, and Other EPA Programs. EPA is proposing its first rule under the American Innovation and
Manufacturing (AIM) Act of 2020 to phase down the production and consumption of
hydrofluorocarbons (HFCs), highly potent greenhouse gases commonly used in refrigerators, air
conditioners, and many other applications. The AIM Act, which was included in the Consolidated
Appropriations Act, 2021, provides EPA new authorities to address HFCs in three main areas: phasing
down the production and consumption of listed HFCs, maximizing reclamation and minimizing
releases (via air, water, or soil) of these HFCs and their substitutes in equipment (e.g., refrigerators
and air conditioners), and facilitating the transition to next-generation technologies by restricting the
use of HFCs in particular sectors or subsectors.
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Comment Excerpt from Commenter 84
September 17, 2021
Radhika Fox
Assistant Administrator
Office of Water
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Re: Docket: EPA-HQ-OW-2018-0594-0031
Dear Administrator Fox:
The Maryland Department of the Environment (MDE) appreciates the opportunity to comment on the
Fifth Contaminant Candidate List (CCL5). MDE's comments mainly address the inclusion of the group
of PFAS compounds under CCL5. MDE understands that EPA is proposing to add "PFAS" as a group
under CCL5 and is using the following definition of PFAS:
"The structural definition of PFAS includes per- and polyfluorinated substances that structurally
contain the unit R-(CF2)-C(F)(R')R". Both the CF2 and CF moieties are saturated carbons and none of
the R groups (R, R' or R") can be hydrogen."
This definition appears to be the same definition of PFAS that EPA included in its recently proposed
TSCA Section 8 rule for PFAS. In that proposed rule, EPA explains that this definition covers "at least
1,364 chemical substances and mixtures".
Typically, the listing of compounds on a CCL (Contaminant Candidate List) occurs before a decision to
add such compounds to an Unregulated Contaminant Monitoring Rule (UCMR). In this case, 29 of the
PFAS compounds proposed for inclusion on the CCL5 seem to have already been added to the UCMR5
(in March of 2021), so MDE understands that the next decision for EPA with regard to these 29
compounds will be to decide (based on monitoring results) whether to proceed to develop drinking
water regulatory standards for these 29 PFAS compounds. MDE urges EPA not to delay that decision
for this subset of 29 PFAS compounds during the pendency of an EPA decision on whether to include
the other approximately 1,335 PFAS compounds included in the CCL5 in the next UCMR (UCMR6). EPA
should make clear in the final CCL5 action how the CCL5 listing that includes these 29 PFAS relates to
the UCMR 5 sampling and the timing of decisions on whether to pursue MCLs for any of these 29
compounds. While further study is always helpful, it is important to ensure that including these 29
PFAS in CCL5 does not inadvertently introduce additional delays in EPA decisions on MCLs for these
compounds.
Moreover, Maryland, similar to many states across the nation, has already initiated a substantial
statewide effort to assess the occurrence of PFAS in state drinking water sources, and MDE urges EPA
to consider using State data on the occurrence of PFAS compounds in public water systems to
expedite decision making on SDWA standards for certain PFAS compounds. Specifically, MDE urges
EPA to expedite decision making on the need for SDWA standards for the 18 PFAS compounds listed
under EPA Method 537.1 and not wait for the results of the UCMR5 for these 18 compounds if
sufficient state-generated data already exists to assess occurrence.
The effort between MDE and the Maryland Department of Health (MDH) to assess occurrence of 18
PFAS in public water systems in Maryland has involved the analysis by MDH of drinking water samples
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for the 18 PFAS listed under EPA Method 537.1. Attached is MDE's Final Report on the results of the
first phase of this effort. In brief, this report indicates that of the 18 PFAS compounds looked for, that
the following PFAS compounds may be the most commonly found in Maryland drinking water
resources (list of compounds listed from most commonly found to least commonly found): PFOA,
PFBS, PFHxA, PFHxS, PFOS, PFHpA, PFNA, PFDA (detected in only 1 sample), and 9CI-PF30NS
(detected in only 1 sample). Additional sampling is being conducted across the State, and MDE
estimates that its statewide assessment for PFAS in Community Water Systems will be completed in
2022-before the start of UCMR5. The State is also already collecting non-targeted data on water from
hundreds of sites across Maryland. This new methodology should provide a large dataset to assess
the 1300+ PFAS defined in CCL5, provided that standardized high-quality libraries become available
for the analysis of this collected data.
With regard to EPA's proposal to list PFAS as a group of 1300+ PFAS compounds on CCL5, while MDE
agrees that the grouping of certain PFAS may be beneficial, the Department encourages that
groupings are scientifically based, but cautions that re-evaluating and/or broadening the R-(CF2)-
C(F)(R')R" definition may be warranted to ensure that it does not exclude any relevant species.
With variations in the extent of fluorination, chain length, and other chemical and physical properties,
no two PFAS compounds are the same. The structural differences amongst the compounds may result
in important differences in toxicity, fate and transport, safe disposal options, and more. Because of
this, MDE encourages that if the EPA pursues a group-based regulation for PFAS compounds, the
toxicity and science behind these regulations must be able to address the variability among
compounds in order to construct scientifically defensible MCLGs and MCLs.
MDE also recommends that EPA facilitate or provide:
• Increased data sharing of PFAS occurrence data in drinking water sources among states, especially
within the same region.
• Training on how states can access PFAS occurrence data from others.
• More tailored resources and/ or training for water utilities and state agencies on the treatment of
PFAS containing source water. Training should specifically address removal options, cost of treatment,
and the maintenance of treatment systems at certain concentrations of PFAS.
• Resources for water utilities impacted by historical releases of PFAS from industries,
manufacturers, and other users of the compounds.
Sincerely,
D. Lee Currey
cc: Ben Grumbles, Secretary, Maryland Department of the Environment
Attachment
Individual Response: Please see Discussion on PFAS. Other Drinking Water Programs, and Other EPA
Programs.
Comment Excerpt from Commenter 88
September 17, 2021
Environmental Protection Agency
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1200 Pennsylvania Avenue, NW Washington, DC 20460
Submitted electronically via regulations.gov
Re: The Safe Drinking Water Act ("SDWA") Draft Contaminant Candidate List 5
Silent Spring Institute is an independent research organization that investigates links between the
environment and women's health, with a focus on breast cancer. It was founded as a collaboration of
scientists, clinicians, and families affected by breast cancer, with a mission to conduct environmental
health research that can inform disease prevention. We have studied PFAS in drinking water [FNi:
Schaider, L. A., Rudel, R. A., Ackerman, J. M., Dunagan, S. C., & Brody, J. G. (2014). Pharmaceuticals,
perfluorosurfactants, and other organic wastewater compounds in public drinking water wells in a
shallow sand and gravel aquifer. Science of the Total Environment, 468, 384-393.] [FNii: Hu, X. C.,
Andrews, D. Q., Lindstrom, A. B., Bruton, T. A., Schaider, L. A., Grandjean, P., ... & Sunderland, E. M.
(2016). Detection of poly-and perfluoroalkyl substances (PFASs) in US drinking water linked to
industrial sites, military fire training areas, and wastewater treatment plants. Environmental science
& technology letters, 3(10), 344-350.] consumer products, [FNiii: Schaider, L. A., Balan, S. A., Blum, A.,
Andrews, D. Q., Strynar, M. J., Dickinson, M. E., ... & Peaslee, G. F. (2017). Fluorinated compounds in
US fast food packaging. Environmental science & technology letters, 4(3), 105-111.] [FNiv: Boronow,
K. E., Brody, J. G., Schaider, L. A., Peaslee, G. F., Havas, L., & Cohn, B. A. (2019). Serum concentrations
of PFASs and exposure-related behaviors in African American and non-Hispanic white women. Journal
of exposure science & environmental epidemiology, 29(2), 206-217.] and blood [FNv: Trowbridge, J.,
Gerona, R. R., Lin, T., Rudel, R. A., Bessonneau, V., Buren, H., & MorelloFrosch, R. (2020).] Exposure to
perfluoroalkyl substances in a cohort of women firefighters and office workers in San Francisco.
Environmental science & technology, 54(6), 3363-3374. as this class of chemicals is associated with a
wide range of adverse health outcomes including cancers, hormone disruption, thyroid disease, and
reproductive, developmental, and immune toxicity. [FNvi: Agency for Toxic Substances & Disease
Registry (ATSDR). (2019a). Toxicological Profile for Perfluoroalkyls.
https://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=1117&tid=237 ] Silent Spring currently has 3
federally funded research studies on PFAS, including 1) Massachusetts PFAS and Your Health Study,
part of a larger study funded by CDC/ATSDR to study health effects of PFAS exposures from drinking
water, 2) PFAS-REACH, which is assessing the relationship between PFAS and pediatric
immunotoxicity, and 3) STEEP, led by the University of Rhode Island, which is investigating the
environmental transport of PFAS and health effects related to exposure.
We appreciate the opportunity to provide comments on a listing of PFAS on the Safe Drinking Water
Act ("SDWA") Draft Contaminant Candidate List 5. While we commend EPA for listing PFAS as a group
in these initial steps toward increased regulation of PFAS in drinking water, the current structural
definition of PFAS in the proposed rule [FNI: EPA's definition is the following: "[T]he structural
definition of PFAS includes per- and poly-fluorinated substances that structurally contain the unit R-
(CF2)-C(F)(R')R". Both the CF2 and CF moieties are saturated carbons and none of the R groups (R, R'
or R") can be hydrogen." ] is too narrow. Rather than this definition, EPA could include all the PFAS
included in its Master List of PFAS, [FNvii: U.S. Environmental Protection Agency (EPA). (2021). PFAS
Master List of PFAS Substances (Version 2).
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https://comptox.epa.gov/dashboard/chemical_lists/pfasmaster ] a list which currently contains 9252
chemicals and continues to expand.
Moreover, EPA needs to increase its analytical capacity to regulate PFAS as a class. Current EPA
methods 533, 537, and 537.1 support the analysis of only 29 PFAS chemicals in drinking water, a small
subset of PFAS present in the environment, and do not include many precursor compounds. These
precursors have the potential to transform into PFOS, PFOA, and other highly stable PFAS endpoints
in the environment and in our bodies. Because many PFAS are detected outside of those included in
EPA's methods, it makes sense for EPA to develop approved methods that measure total impact from
PFAS. One analytical method that could complement existing EPA methods is the total oxidizable
precursor assay, or TOP assay, which is a commercially available method for evaluating the presence
of precursor compounds. Using the TOP Assay would provide a more complete evaluation of PFAS
precursors in water. Another approach for measuring all PFAS emissions would be Total Organic
Fluorine (TOF), which is a rapid screening tool to identify total PFAS presence. We also suggest EPA
consider additional analytical methods as they become available. For instance, the European
Commission announced in December 2019 that it would develop a method to measure total PFAS in
water within 3 years and to set a limit for drinking water. [FNviii: European Parliament. Trilogue
results of the revision of the Drinking Water Directive, https://sven-giegold.de/wp-
content/uploads/2019/12/Media-briefing-Drinking-water-19.12.2019.pdf ]
There are multiple ways that EPA could incorporate total organofluorine measurements into drinking
water standards, and we urge EPA to allocate the appropriate resources for rapidly developing the
capacity to do so in advance of promulgating new drinking water regulations for PFAS.
Thank you for the opportunity to provide comments. We look forward to EPA's response.
Sincerely,
Jennifer Liss Ohayon, PhD
Research Scientist
Robin E. Dodson, Sc.D.
Research Scientist
Laurel Schaider, PhD
Senior Research Scientist
Individual Response: Please see Discussion on PFAS. PFASMASTER serves as a consolidated list of
PFAS substances spanning and bounded by the lists of chemicals of current interest to researchers
and regulators worldwide. The consolidated list contains a number of PFAS CAS-name substances,
with a subset represented with defined chemical structures. For the PFASMASTER list, there is no
precisely clear definition of what constitutes a PFAS substance given the inclusion of partially
fluorinated substances, polymers, and ill-defined reaction products on these various lists. At this time,
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EPA is opting to use a more inclusive CCL 5 PFAS definition, with chemically defined substructures, to
represent those chemicals that are known or anticipated to occur in public water systems and is not
prematurely excluding volatiles or fluoropolymers from further evaluation. EPA is also providing a list
of PFAS that meet the CCL 5 structural definition (WATER | EPA: Chemical Contaminants - CCL 5 PFAS
subset) on its CompTox dashboard (https://comptox.epa.gov/dashboard/chemical-lists).
Comment Excerpt from Commenter 89
I. EPA SHOULD ADDRESS PFAS AS A CLASS
A. EPA Should include PFAS as a Class, Broadly Defined
Several scientists with extensive expertise in per- and polyfluoroalkyl substances (PFAS) chemistry and
toxicity, many affiliated with the Global PFAS Science Panel, [FN1:
https://www.pfassciencepanel.org/about-us] have submitted extensive comments supporting listing
PFAS as a class on CCL5 but noting that EPA's proposed definition is unduly narrow. We hereby join
those comments and incorporate them by reference. As the scientists note, a strength of the proposal
is that it applies a class-based approach to addressing PFAS. However, as they point out, EPA's "overly
narrow definition of PFAS would exclude many PFAS of known concern, undercutting the benefits of
the agency's action." [FN2: Proposed definition from both TSCA and SDWA proposed rulemakings:
"[T]he structural definition of PFAS includes per- and poly-fluorinated substances that structurally
contain the unit R-(CF2)C(F)(R')R". Both the CF2 and CF moieties are saturated carbons and none of
the R groups (R, R' or R") can be hydrogen." https://www.regulations.gov/document/EPA-HQ-OPPT-
2020-0549-0001; https://www.regulations.gov/document/EPA-HQ-OW-2018-0594-0031 ] For the
reasons set forth in the scientists' letter and the attached scientific journal article, we urge EPA to use
the OECD PFAS definition, [FN3: OECD (2021), Reconciling Terminology of the Universe of Per- and
Polyfluoroalkyl Substances: Recommendations and Practical Guidance, OECD Series on Risk
Management, No. 61, OECD Publishing, Paris. Available at:
https://www.oecd.org/chemicalsafety/portal-perfluorinatedchemicals/terminology-per-and-
polyfluoroalkyl-substances.pdf] which is scientifically sound and consistent with definitions that have
been included in federal and state laws regulating PFAS. As the scientists' letter emphasizes, PFAS as a
class pose dangers to human and environmental health. Due to the presence of the highly stable fully
fluorinated carbon moieties, PFAS are either extremely resistant to environmental degradation - or
transform into other highly persistent PFAS. Studies have shown that some PFAS take thousands of
years to fully degrade. Their highly persistent nature further enables PFAS to accumulate in the
environment, including in water, sediment, soil, and plants. [FN4: Kwiatkowski, C. F.; Andrews, D. Q.;
Birnbaum, L. S.; Bruton, T. A.; DeWitt, J. C.; Knappe, D. R. U.; Maffini, M. V.; Miller, M. F.; Pelch, K. E.;
Reade, A.; Soehl, A.; Trier, X.; Venier, M.; Wagner, C. C.; Wang, Z.; Blum, A. Scientific Basis for
Managing PFAS as a Chemical Class. Environ. Sci. Technol. Lett. 2020, 7 (8), 532- 543, DOI:
10.1021/acs.estlett.0c002] Multiple lines of scientific evidence suggest that many PFAS can contribute
to a wide range of adverse health outcomes, including cancer, endocrine disruption, reproductive
harm, and immunosuppression. [FN5: Pelch, K., Reade, A., Kwiatkowski, C., Schultz, K., Varshavsky, J.,
Cavalier, H., ... Wolffe, T. (2021, June 7). PFAS Health Database: A Systematic Evidence Map.
https://doi.org/10.17605/OSF.IO/F9UPX; Kwiatowski et al, 2020 note 6 supra.] The attached scientific
review of the studied human and environmental health harms posed by PFAS recommends adoption
of a "class-based approach to managing the human and environmental risks associated with all PFAS,
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including polymers." [FN6: Kwiatowski et al, 2020 note 6 supra ] The scientists' letter concludes that
EPA's proposed PFAS definition in the SDWA CCL5 listing, quoted below, "is scientifically unsupported,
does not include all PFAS, and denies the Agency critical information about PFAS." The agency
definition is: "[T]he structural definition of PFAS includes per- and poly-fluorinated substances that
structurally contain the unit R-(CF2)-C(F)(R')R". Both the CF2 and CF moieties are saturated carbons
and none of the R groups (R, R' or R") can be hydrogen." [FN7: Cite to definition in TSCA and SDWA
proposed agency actions.]
As the scientists point out, EPA did not identify any scientific support for this proposed definition, and
it "is particularly concerning that EPA's proposed definition excludes many high production volume
PFAS due to its unduly narrow requirement for the presence of at least two adjacent fully-fluorinated
carbons. For example, trifluoroacetic acid ("TFA") is a common HFC and HFO degradation product that
poses risk to human health. [FN8: Several of the commenting scientists noted above co-authored a
rebuttal to industry comments in which they highlighted health concerns posed by TFA. See,
Response to "Comment on Scientific Basis for Managing PFAS as a Chemical Class." Carol F.
Kwiatkowski, David Q. Andrews, Linda S. Birnbaum, Thomas A. Bruton, Jamie C. DeWitt, Detlef R.U.
Knappe, Maricel V. Maffini, Mark F. Miller, Katherine E. Pelch, Anna Reade, Anna Soehl, Xenia Trier,
Marta Venier, Charlotte C. Wagner, Zhanyun Wang, and Arlene Blum. Environmental Science &
Technology Letters 2021 8 (2), 195-197. DOI: 10.1021/acs.estlett.lc00049] and has been widely
recognized as a PFAS by the California Department of Toxic Substances Control and others, [FN9:
https://dtsc.ca.gov/wp-content/uploads/sites/31/2019/ll/Product-Chemical-Profile-for-
Treatmentswith-PFASs.pdf] but falls outside of EPA's proposed definition because it only possesses
one fully fluorinated carbon. Like other PFAS, "TFA is highly persistent and mobile in the environment,
and has also been linked to adverse health outcomes like skin and eye damage and harm to aquatic
life." [FN10: Scientists' letter, citing Kwiatkowski et al, note 14 supra.]
EPA's overly narrow proposed definition incentivizes the chemical industry to try to skirt future
regulatory requirements by making PFAS that possess the characteristics associated with PFAS but fall
outside of EPA's narrow definition. DuPont long studied such compounds. [FN11:
https://www.sciencedirect.com/science/article/pii/S0022113911003782;
https://www.sciencedirect.com/science/article/pii/S002211391400044X] and the chemical industry
has a long history of making minor changes in PFAS chemistry to evade regulation, including the
shifting from PFAS like PFOA and PFOS to shorter-chain PFAS that were erroneously claimed to be less
toxic and persistent, and now pose have caused widespread environmental contamination
threatening human health. [FN12: Buck et al., supra note 3, at 524. See also Mei Sun et al., Legacy and
Emerging Perfluoroalkyl Substances Are Important Drinking Water Contaminants in the Cape Fear
River Watershed Of North Carolina, 3 Env't Sci. & Tech. Letters 415 (2016),
https://pubs.acs.org/doi/full/10.1021/acs.estlett.6b00398; Xianming Zhang et al., Source Attribution
of Poly- and Perfluoroalkyl Substances (PFASs) in Surface Waters from Rhode Island and the New York
Metropolitan Area, 3 Env't Sci. & Tech. Letters 316 (2016),
https://pubs.acs.org/doi/abs/10.1021/acs.estlett.6b00255.]
B. EPA Should Adopt the OECD Definition of PFAS
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We therefore embrace the scientists' suggestion that rather than use the PFAS definition in the draft
CCL5, that EPA adopt the recently-published OECD PFAS definition, in which PFAS are defined as
"fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon atom
(without any H/CI/Br/l atom attached to it)." [FN13: OECD (2021), Reconciling Terminology of the
Universe of Per- and Polyfluoroalkyl Substances: Recommendations and Practical Guidance, OECD
Series on Risk Management, No. 61, OECD Publishing, Paris. Available at:
https://www.oecd.org/chemicalsafetv/portal-perfluorinatedchemicals/terminology-per-and-
polyfluoroalkyl-substances.pdf.l As OECD stated in explaining this definition, "the intention of the
revision of the PFAS definition is not to expand the PFAS universe, but to comprehensively reflect it.
As the scientists' letter notes, OECD provides "a general PFAS definition that is coherent and
consistent across compounds from the chemical structure point of view and is easily implementable
for distinguishing between PFASs and non-PFASs, also by non-experts." [FN14: Id. at 23.] The OECD
definition is scientifically sound and comprehensive; indeed, EPA scientists were members of the
OECD group that prepared this definition." [FN15: Id. at 5.]
The scientific validity and benefits of the OECD definition are detailed in the scientists' comments and
the OECD report noted above, and we refer EPA to those comments. In sum, the scientists note that
the OECD definition: (1) covers all fluorinated chemicals that share common characteristics of PFAS,
including persistence in the environment; (2) will expand the data EPA receives about use of, and
exposures to, PFAS in the United States (as the scientists note, EPA's Comptox Database now
indicates that there are over 9,000 PFAS [FN16: PFAS Master List of PFAS Substances (Version2), EPA,
https://comptox.epa.gov/dashboard/chemical_lists/pfasmaster] and only 175 of these are subject to
recordkeeping and reporting requirements under the Toxics Release Inventory (TRI)); [FN17:
https://www.epa.gov/sites/default/files/2021-01/documents/tri_non-
cbi_pfas_list_l_8_2021_final.pdf] and (3) is consistent with several federal and state laws that have
already employed comparable definitions of PFAS. For example, the National Defense Authorization
Act for Fiscal Year 2020 defined PFAS as "perfluoroalkyl and polyfluoroalkyl substances that are man-
made chemicals with at least one fully fluorinated carbon atom." [FN18:
https://congress.gov/116/plaws/publ92/PLAW-116publ92.pdf, see TITLE II. SEC322.C.3 ] Since 2019,
eight states have passed laws using similar, broad definitions of PFAS that are consistent with OECD's,
including California, [ FN19:
https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201920200SB1044] Colorado,
[FN20: http://leg.colorado.gov/sites/default/files/2019a_1279_signed.pdf] Maine, [FN21:
http://www.mainelegislature.org/legis/bills/getPDF.asp?paper=HP1043&item=l&snum=129]
Vermont, [FN22:
https://legislature.vermont.gov/Documents/2022/Docs/ACTS/ACT036/ACT036%20As%20Enacted.pdf
] and Washington. [FN23: http://lawfilesext.leg.wa.gov/biennium/2019-
20/Pdf/Bills/Senate%20Passed%20Legislature/5135S.PL.pdf?q=20210811124919] It would create
needless confusion if EPA's new regulatory actions adopted different definitions of PFAS than those
already in place in federal and state laws.
Individual Response: Please see Discussion on PFAS. EPA is proposing its first rule under the American
Innovation and Manufacturing (AIM) Act of 2020 to phase down the production and consumption of
hydrofluorocarbons (HFCs), highly potent greenhouse gases commonly used in refrigerators, air
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conditioners, and many other applications. The AIM Act, which was included in the Consolidated
Appropriations Act, 2021, provides EPA new authorities to address HFCs in three main areas: phasing
down the production and consumption of listed HFCs, maximizing reclamation and minimizing
releases (via air, water, or soil) of these HFCs and their substitutes in equipment (e.g., refrigerators
and air conditioners), and facilitating the transition to next-generation technologies by restricting the
use of HFCs in particular sectors or subsectors.
Comment Excerpt from Commenter 93
Thank you for including the 3 chemical groups that PFAS is part of in the list. This needs to be tested
in our drinking water and treated.
Individual Response: Please see Discussion on PFAS.
Comment Excerpt from Commenter 98
This proposal to put limits on all of these microbes and chemicals as a part of the new CCL 5 is a no-
brainer. The inclusion of PFAS and other long-chain chemical compounds that can bio-accumulate in
the human body is a real positive.
Individual Response: Please see Discussion on PFAS. General Comments, and Other Drinking Water
Programs.
Comment Excerpt from Commenter 103
Dear Administrator Regan,
Thank you for this opportunity to comment on EPA's draft Fifth Contaminant Candidate List (Draft
CCL5) under the Safe Drinking Water Act (SDWA). I support EPA regulating all of the dangerous
contaminants on the SDWA candidate list. It is especially important that EPA include and set safe
drinking water limits on groups of extremely hazardous chemicals like cyanotoxins, disinfection
byproducts, and PFAS.
But it is also important that EPA make review and listing of additional unregulated contaminants a
priority. I'm talking about all known PFAS. We need EPA to ensure our drinking water is safe from all
of the toxic and hazardous chemicals that are being released into the environment. There are known
pfas that are not listed on the EPAs radar and that is very concerning to me. Also there there a lack of
awareness to what PFAS actually are and not a lot of normal people are aware of this danger and that
needs to change NOW. To do that, EPA must increase staffing and speed up the process for reviewing
the contaminants and setting legal limits on how much can be in our drinking water.
Because the public's health and safety is threatened by so many new contaminants, I am STRONGLY
URGING YOU because this problem is BEYOND HORRENDOUS and people are dying because of
UNSAFE DRINKING WATER and this problem is ENTIRELY PREVENTABLE that you set strict standards
on the most dangerous chemicals/ PFAS and anything like PFAS to cause bodily harm and err on the
side of protecting the public when data is limited. The health of our nation, and particularly children
and underserved communities, depends on it.
Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that includes PFOA,
PFOS, GenX, and many other chemicals. PFAS have been manufactured and used in a variety of
industries around the globe, including in the United States since the 1940s. PFOA and PFOS have been
the most extensively produced and studied of these chemicals. Both chemicals are very persistent in
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the environment and in the human body - meaning they don't break down and they can accumulate
over time. There is evidence that exposure to PFAS can lead to severe and life threatening adverse
human health effects.
PFAS can be found in:
Pretty much everything now..
Food packaged in PFAS-containing materials, processed with equipment that used PFAS, or grown in
PFAS-contaminated soil or water.
Commercial household products, including stain- and water-repellent fabrics, nonstick products (e.g.,
Teflon), polishes, waxes, paints, cleaning products, and fire-fighting foams (a major source of
groundwater contamination at airports and military bases where firefighting training occurs).
Workplace, including production facilities or industries (e.g., chrome plating, electronics
manufacturing or oil recovery) that use PFAS.
Drinking water, typically localized and associated with a specific facility (e.g., manufacturer, landfill,
wastewater treatment plant, firefighter training facility).
Living organisms, including fish, animals and humans, where PFAS have the ability to build up and
persist over time.
Studies indicate that PFOA and PFOS can cause reproductive and developmental, liver and kidney,
and immunological effects in laboratory animals. Both chemicals have caused tumors in animal
studies. The most consistent findings from human epidemiology studies are increased cholesterol
levels among exposed populations, with more limited findings related to: infant birth weights, effects
on the immune system, cancer (for PFOA), and thyroid hormone disruption (for PFOS).
Oral exposure studies of PFBS in animals have shown effects on thyroid hormone disruption,
reproductive organs and tissues, developing fetus, and kidney. Based on dose-response information
across different sexes, lifestages, and durations of exposure, the thyroid appears to be particularly
sensitive to oral PFBS exposure. The data to evaluate cancer effects associated with PFBS exposure is
unknown at this time but will in no way will the data ever show that the health effects are positive.
Do something right now before this is completely irreversible and we all suffer the consequences no
matter wealth or age, race nor gender you will doom us all if you don't act now....
Individual Response: Please see Discussion on PFAS.
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Pesticides
Agency Discussion on Pesticides
Comment Excerpt from Commenter 77
In describing how EPA prepared the Draft CCL 5, the technical support document indicates the Agency
utilized existing health effects assessments to the degree possible. In reviewing the health reference
levels listed in the Contaminant Information Sheets for pesticides listed on the Draft CCL 5, it appears
that EPA made different assumptions in setting the health reference levels used in CCL 5 than in the
Human Health Benchmarks for Pesticide update, which were published in parallel. [FN24: EPA. 2021.
Human Health Benchmarks for Pesticides (HHBPs). Accessed 9/8/2021 at
https://ordspub.epa.gov/ords/pesticides/f?p=HHBP:home.1
In part this difference appears to be the result from choosing different sensitive subpopulations.
While it may be sound practice for EPA to utilize different assumptions compared to FIFRA
assessments that are several years old, it is not clear why 16 of 24 contemporaneous health reference
levels prepared by the Office of Water would differ with 14 citing different sensitive subpopulations.
Individual Response: EPA understands the concerns raised about the differences in the selection of
the most sensitive subpopulation that were used in EPA's CCL 5 and EPA's HHBP processes. The
commenter accurately states that for 14 pesticides, while the selected toxicity value (e.g., chronic
population-adjusted dose (cPAD)) used as the basis of the CCL 5 health reference level (HRL) and
HHBP were the same, the selected sensitive subpopulation and subsequent selection of the drinking
water ingestion rate input were different. In the CCL 5 process, EPA's Office of Water (OW) used a
consistent approach of selecting the most health-protective target population for all contaminants,
including pesticides with available assessments published by the Office of Pesticide Programs (OPP).
In this approach, the most sensitive subpopulation was selected among five populations (i.e., general
population, bottle-fed infants, women of childbearing age (13-49 years), pregnant women, and
lactating women) by examining the critical study and critical effect that was used to derive the PAD
extracted from an OPP health assessment.
The updated Human Health Benchmarks for Pesticides (HHBPs) were developed by OW in
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collaboration with OPP. HHBPs were established for acute and chronic effects by applying PADs
established for the most sensitive life stage/population as determined by OPP, based on the available
toxicity data from OPP's pesticide registration and reregistration review processes. For further
information about derivation of EPA's HHBPs, see
https://www.epa.gov/system/files/documents/2021-07/hh-benchmarks-technical-document-
2021.pdf.
Comment Excerpt from Commenter 91
I support expanding the list of chemicals to be regulated under the Safe Drinking Water Act. I read
through the list of currently unregulated chemicals and recognized a number of pesticides that I have
experience with. Several of them I know to be fairly broad spectrum and while they may not be
acutely toxic in mammals I don't want them building up in our water supply. The water supply is the
foundation of human life in America and if we poison our water the results will be catastrophic. I
would like to point out that concentrations of these chemicals will be much higher in the water supply
in rural, agricultural regions, and could affect much wider swaths of land than other pollutants,
making detection more difficult.
Individual Response: Please see Discussion on Pesticides.
Comment Excerpt from Commenter 92
I would support the drafting of this list and potential future regulation of the chemicals contained by
it. The Clean Drinking Water Act is a fundamentally important environmental law and the list of
chemicals that are regulated by it should be updated to reflect the pollutants we are putting in our
water supply. In reading this document I recognized a fair number of pesticide active ingredients and
many of them were fairly broad-spectrum. Even if they are not acutely toxic in mammals I don't want
them to build up in our water supply and potentially in human bodies. The water supply is the
foundation of life in this country and every country and if we destroy it then the results will be
catastrophic. I would like to note that these chemicals will likely be found in greater concentrations in
rural, agrarian regions and therefore be present across wider tracts of land, making detection
potentially more challenging,
Individual Response: Please see Discussion on Pesticides.
Individual Chemical Contaminants
Agency Discussion on Comments on Individual Chemical Contaminants
Agency Topic Discussion:
EPA received several comments regarding the listing status or information collected for individual
contaminants listed on the Draft CCL 5. Some commenters expressed support for the listing of specific
contaminants while others disagreed with EPA's evaluation and requested EPA reconsider listing
specific contaminants on the Final CCL 5.
Some commenters provided resources and analyses that they recommended EPA consider when
listing a contaminant of interest. EPA followed protocols and established hierarchies for the data used
at each step of the CCL 5 process. These protocols and hierarchies were applied uniformly across all
chemical contaminants [See Chapter 4 Classification of PCCL Chemicals to Select the CCL of the Final
CCL 5 Chemical Technical Support Document (USEPA. 2022a)1. For example, toxicity values (i.e.,
reference doses) used to derive health reference levels and final hazard quotients were preferentially
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selected from health assessments that are externally peer-reviewed, publicly available, and published
by EPA and other health agencies that follow methodologies consistent with EPA's current health
effects guidelines and risk assessment policy documents. The recommendations provided by
commenters often conflicted with this protocol and other procedures used during the CCL 5 process.
However, public comments about the CCL 5 protocol's strengths and weaknesses will be useful when
reviewing whether to make protocol modifications in future CCLs.
Some commenters recommended considerations or analyses that are outside the scope of the CCL
process. However, placement on the CCL enables EPA to subsequently examine the available toxicity
and occurrence databases in the more focused Regulatory Determination process to determine if a
contaminant has sufficient data for regulation in drinking water. Regulatory Determination under
SDWA will be the next stage in the regulatory process for all contaminants listed on the Final CCL 5.
1,4-Dioxane
Comments Received on 1,4-Dioxane
Comment Excerpt from Commenter 75
1,4-dioxane
ASDWA supports the inclusion of 1,4-dioxane as a contaminant on CCL 5. 1,4-dioxane has been widely
used as a solvent and organic solvent stabilizer in the past. It has also been a component of many
personal care products. EPA has classified 1,4-dioxane as a likely human carcinogen and established a
1-day health advisory of 4.0 milligrams per liter (mg/L) and a 10-day health advisory of 0.4 mg/L for
l,4dioxane in drinking water for a 10-kilogram child. EPA also established a lifetime health advisory of
0.2 mg/L for 1,4-dioxane in drinking water.
Contamination of both groundwater and surface water sources of drinking water from 1,4- dioxane is
extensive. The results of the Third Unregulated Contaminant Monitoring Rule (UCMR3) found that of
the 4,916 public water systems (PWS) tested, 1,077 PWSs in 45 states detected 1,4-dioxane above
0.07 ppb, and 6.9% of PWSs detected 1,4-dioxane above 0.35 ppb. Since the UCMR monitoring
universe is the approximately 4,000 PWSs that serve over 10,000 people plus approximately 800
smaller systems, these sample results represent only a fraction of the over 50,000 Community Water
Systems (CWSs), which are a subset of the over 150,000 PWSs. The additional PWSs that may be
impacted by 1,4-dioxane and were not included in the UCMR3 are typically small groundwater
systems with limited capacity to assess and address 1,4- dioxane. The vast majority of UCMR3 PWSs
were surface water systems.
In the absence of a federal standard, some states across the country are taking additional actions to
address public health impacts from 1,4-dioxane drinking water contamination in both surface water
and groundwater sources. However, other states are unable to develop their own guidelines or
regulations that are more stringent than federal standards, and/or do not have the resources to
conduct sampling programs. Four states have developed state-level regulatory actions in the absence
of a federal standard: New York established a MCL for 1,4-dioxane at 1 ppb; Massachusetts
established a drinking water guideline at 0.3 ppb; California established a health action level of 1 ppb;
and New Hampshire established an ambient groundwater quality standard (AGQS) level of 0.32 ppb.
Additionally, 14 other states have established groundwater or drinking water standards or guidelines
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with levels ranging from 0.3 to 77 ppb.
EPA taking a leadership in driving this chemical through its drinking water standards development
process would benefit several states, as setting and implementing a drinking water exposure limit for
1,4-dioxane presents challenges to the states. Additionally, ASDWA requests the Office of Water
continue to coordinate with EPA's Office of Chemical Safety and Pollution Prevention (OCSPP) to
ensure the risk evaluation for 1,4-dioxane under the Toxic Substances Control Act (TSCA) includes
drinking water as an exposure pathway.
Individual Response: Please see Discussion on Individual Chemical Contaminants and Other Drinking
Water Programs. EPA appreciates the information provided by the commenter that supports the
inclusion of 1,4-dioxane on the CCL 5. EPA acknowledges the commenter's concerns about 1,4-
dioxane and challenges faced by states with known surface water and/or groundwater
contamination. Nationally representative finished drinking water occurrence data for 1,4-dioxane are
available from the Third Unregulated Contaminant Monitoring Rule (UCMR 3; docket EPA-HQ-OW-
2009-0090). Please see the Discussion on Individual Chemical Contaminants for information about the
next steps in the regulatory process for 1,4-dioxane.
The Office of Pollution prevention and Toxics (OPPT) published the Risk Evaluation for 1,4-Dioxane in
December 2020 (docket EPA-HQ-OPPT-2019-0238; https://www.regulations.gov/document/EPA-HQ-
QPPT-2019-0238-0091). During the risk evaluation process for 1,4-Dioxane, OCSPP collaborated with
offices within EPA that administer and implement regulatory programs under the Clean Air Act (CAA),
the Safe Drinking Water Act (SDWA), the Clean Water Act (CWA), the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) and the Resource Conservation and Recovery Act
(RCRA). The agency is continuing to evaluate 1,4-dioxane. More information on the Risk Evaluation for
1,4-dioxane is available at Assessing and Managing Chemicals under TSCA: Final Risk Evaluation for
1,4-Dioxane.
Chlorpyrifos
Comments Received on Chlorpyrifos
Comment Excerpt from Commenter 89
Similarly, EPA issued a 2016 Revised Human Health Risk Assessment (HHRA) that demonstrated that
chlorpyrifos results in unsafe drinking water exposures and adverse neurodevelopmental effects and
that EPA therefore was required to issue a final rule revoking all chlorpyrifos tolerances. [FN31:
Summarized in EPA, Chlorpyrifos; Tolerance Revocations, August 18, 2021,
https://www.epa.gov/system/files/documents/2021-08/pre-pub-5993-04-ocspp-fr_2021-08-18.pdf]
The agency recently issued a final rule revoking all chlorpyrifos tolerances based on aggregate
exposures including drinking water. [FN32: Ibid.] However, chlorpyrifos is still in use, is allowed for
non-food uses, and its toxic degradates may remain in the environment for years. We urge an
affirmative regulatory determination without further delay.
Individual Response: Please see Discussion on Individual Chemical Contaminants. Other Drinking
Water Programs, and Other EPA Programs.
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Cobalt
Comments Received on Cobalt
Comment Excerpt from Commenter 74
Comments on the draft chemical contaminant list 5 (CCL5) with reference to cobalt
Submitted by Cobalt Institute
EPA Document ID: EPA-HQ-OW-2018-0594-0031
Cobalt Institute
18 Jeffries Passage
Guildford, Surrey
GUI4AP
United Kingdom
https://www.cobaltinstitute.org/
Contact: rdanzeisen@cobaltinstitute.org and vviegas@cobaltinstitute.org
The Cobalt Institute (CI) is a trade association composed of producers, users, recyclers, and traders of
cobalt. We promote the sustainable and responsible production and use of cobalt in all its forms. Both
the CI and the Cobalt REACH Consortium (European Union) have invested in high quality, guideline
compliant studies to address human health hazard characterization and accompanying risk
assessment for different global jurisdictions.
We submit the following comments with regards to the draft chemical contaminant list 5 (CCL5)
cobalt assessment.
1. The use of the chronic RfD from USEPA PPRTV 2008 to derive the cobalt HRL
• We raise concerns regarding the use of Roche and Layrisse 1956 reference [FN1: Roche, M. and M.
Layrisse. 1956. Effect of cobalt on thyroidal uptake of 1131. J. Clin. Endocrinol. Metab. 16:831-833.] as
the point-of departure for the sub- and chronic RfD in PPRTV 2008 [FN2: USEPA. 2008. Provisional
Peer Reviewed Toxicity Values for Cobalt (CASRN 7440-48-4). PA/690/R-08/008F. U.S. Environmental
Protection Agency, Office of Research and Development, National Center for Environmental
Assessment, Superfund Health Risk Technical Support Center, Cincinnati, OH.], and thereby used in
the derivation of the cobalt HRL in the draft CCL 5 CIS. The aforementioned reference was a two-page
letter to the editor (i.e. unclear if peer-reviewed) and further, the genders of the 12 euthyroid
participants were not specified. These points were also published in a peer-reviewed manuscript
[FN3: Finley et al. 2012. Derivation of a chronic oral reference dose for cobalt. Reg. Tox. And Pharm.
64:491-503],
• The effect that the HRL is derived for is listed in the draft Co CIS as 'reproductive/developmental'
and associated with a target population of 'women of childbearing age'. As listed in point 1 above, the
key study did not specify gender and the key effect was decreased radioactive iodine uptake. In
addition, there was argumentation in the derivation of the RfD (PPRTV 2008) to derive a safe level
based on the thyroid effect instead of hematological effect, as the former was hypothesized to lead to
increased toxicity at a longer duration or higher dose in a sensitive population specifically relating to
goiter in previously anemic children.
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• The chronic RfD derivation contains an uncertainty factor of 10 as 'cobalt may not be rapidly
eliminated from the body' (after subcutaneous treatment). This should be reviewed using Danzeisen
et al. 2020, as listed under point 2 below; in which GLP, OECD compliant toxicokinetic data have been
published for a highly bioavailable cobalt substance. As observed after an oral bolus dose (in water) of
cobalt dichloride hexahydrate, 10% of the dose was bioavailable, the plasma half-life elimination was
14 hours and total elimination was observed by 72 hours.
• If protecting against the thyroid effect, we ask EPA to consider the Finley et al. 2012 [FN4: Finley et
al. 2012 derivation of a chronic oral reference dose for cobalt. Reg. Tox. And Pharm. 64: 491 - 503.]
derivation of a chronic RfD using Jaimet and Thode 1955 [FN5: Jaimet and Thode 1955. Thyroid
function studies on children receiving cobalt therapy. JAMA 158: 1353 - 1355. 311325.] as point-of-
departure (not referenced in PPRTV 2008) and use of uncertainty factors, specifically contrasted with
those used in EPA's perchlorate assessment based on thyroid effects. Based on our own guideline
compliant studies we would recommend using the hematological effect as point of departure, as
outlined below, since (at least in our studies) it is a more sensitive endpoint than the thyroid effect
and followed a dose response with the possibility to set a LOAEL and a NOAEL.
• We ultimately ask EPA to consider deriving a HRL based on the well-documented hematological
effect induced by bioavailable cobalt substances, using the argumentation that this is a more sensitive
effect in humans, occurring at doses lower than those inducing a thyroid effect and demonstrated as
a key outcome in the mode-of-action for highly bioavailable cobalt substances.
2. The derivation of a cobalt HRL based on protection against a hematological effect (most
sensitive effect)
• We request that the EPA review and include in the draft CCL5 cobalt assessment, the peer-reviewed
reference Danzeisen et al. 2020 [FN6: Danzeisen et al. 2020. Bioelution, bioavailability, and toxicity of
cobalt compounds correlate. Tox Sci. 174(2): 311325.]. This article outlines that the hematological
effect (reversible) is the most sensitive effect/occurs at lower doses than the thyroid effect;
manifesting in large (+20%) increases in hematological parameters and erythroid hyperplasia in a 90-
day oral repeated-dose toxicity study in male and female rats (i.e. LOAEL = 10 mg cobalt dichloride
hexahydrate/kg bw/d, corresponding to 2.5 mg cobalt/kg bw/d) and a NOAEL of 3 mg cobalt
dichloride hexahydrate/kg bw/d, corresponding to 0.75 mg cobalt/kg bw/d). No alterations were
observed in the thyroid (histopathology, gross pathology, organ weight) or clinical chemistry
parameters associated with the thyroid; no changes to reproductive parameters and no
spermatagonial aberrations observed at doses up to 30 mg cobalt dichloride hexahydrate/kg bw/d or
7.5 mg Co/kg bw/d (Danzeisen et al. 2020).
• We ask the EPA to consider derivation of a chronic RfD based on Danzeisen et al. 2020, which would
equate to 30 ng Co/kg-d; using:
o Point-of-departure: NOAEL = 0.75 mg Co/kg-d
Assessment Factor
Accounting for
Value applied
Interspecies variability
Correction for differences in
metabolic rate (allometric
scaling)
1*
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Remaining differences (e.g. TK,
TD)
2.5
Intraspecies
General population
5**
Exposure duration
Sub-chronic to chronic
2
Dose response
NOAEL as POD with reliable
information on dose response
1
Database
Quality of database high
^ *
Overall Uncertainty factor
25
Explanations:
*: metabolism of cobalt as an inorganic substance can be excluded. There are no reasons to assume that this
behavior which is based on the physico-chemical properties of the substance will be different between rats and
humans. Therefore, it is considered to be justified to apply substance-specific assessment factors accounting for
a correction for differences in metabolic rate of 1 instead of using the respective default factors of 4.
**: This assessment factor is used to account for an expected greater variability in response from the most to
least sensitive human would be seen, relative to an experimental animal population. ECETOC (2003) has
reviewed scientific literature on the distribution of human data for various toxicokinetic and toxicodynamic
parameters to assess intra-species variability within the human population, specifically by Renwick and Lazarus
(1998) and Hattis et al. (1999). Considering that the data analyzed by these authors includes both sexes, a
variety of disease states and ages, the use of the 95th percentile of the distribution of the variability for these
datasets is considered sufficiently conservative to account for intraspecies variability for the general population.
Based on this, a default assessment factor of 5 is recommended by ECETOC (2003).
***: key study guideline compliant OECD 408 with reproductive toxicity screening and dose response for leading
effect (hematology)
3. Consideration of the essentiality of cobalt in vitamin B12, natural background levels of cobalt
and the approximate levels in food
• The general population is exposed to anthropogenic and natural sources of cobalt through the air,
water and diet. Diet and oral exposure are the main source of cobalt intake for the general public.
Vitamin B12 has a reference nutrient intake (RNI) value of 2.4 ng of Vitamin B12/day for adults and
2.5 ng/day during pregnancy. Based on figures quoted in ATSDR 2004 [FN7: ATSDR. 2004.
Toxicological Profile for Cobalt. U.S. Department of Health and Human Services, Public Health Service,
Agency for Toxic Substances and Disease Registry (ATSDR), Atlanta, GA.], the average daily intake of
cobalt through food is between 5 - 40 ng Co/day. Inorganic cobalt is not essential to humans and has
a tolerable daily intake value, e.g. set by France at 1.6 - 8 ng/kg bw/d. Cobalt is found in a variety of
food sources such as meat, offal, coffee, yeast products, dairy products, fish, green leafy vegetables,
fresh cereals and nuts. Depending on place of living and background occurrence of cobalt, daily
exposure through the diet can be significantly higher.
• In the form of vitamin B12, cobalt is an essential nutrient for humans. Mammals are not capable of
synthesizing vitamin B12 and need to obtain it through the diet, where it is found only in some
fermented foods or in animal-based food products [FN8: Combs, G.F. and McClung, J.P (eds) 2017.
The Vitamins (5th Edition), Chapter 18 - Vitamin B12. Academic Press, pages 431-452. ISBN:
9780128029657.].
We thank you in advance for the consideration of the points outlined above.
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Individual Response: Please see Discussion on Individual Chemical Contaminants. EPA recognizes the
comments about the critical study used in the PPRTV and appreciates the commenter providing
additional references. It is important to note that the PPRTV value is supported by a second study
(Davis and Field, 1958) that identified polycythemia as the critical effect at similar doses as the thyroid
critical effect. Therefore, there is evidence of two different health endpoints observed after cobalt
exposure in the same dose range. Further, there are multiple human studies that demonstrate the
Davis and Field link between cobalt and polycythemia that support this second health effect resulting
from cobalt exposure.
The connection of the HRL to the reproductive/developmental category is based on the selection of
women of childbearing age as the most sensitive subpopulation for the derivation of the HRL. The
critical effect (decreased iodide uptake by the thyroid) can lead to developmental effects because of
the recognized neurodevelopmental impacts of low dietary iodide on the fetus. The Dietary Reference
Intake (DRI) guidelines recognize the importance of iodide during pregnancy and support use of the
drinking water intake and body-weight ratio selected by EPA for derivation of the HRL (IOM, 2006).
The EPA literature search for recent publications related to the health effects associated with cobalt
in humans and laboratory animals was conducted on October 22, 2019 and therefore did not identify
the Danzeisen et al. (2020) publication. EPA appreciates that the commenters provided a copy of the
article. The publication will be considered as part of the future CCL and Regulatory Determination
evaluations. The Finley publications mentioned in the comment were among the materials reviewed
when cobalt was evaluated for potential regulation during Regulatory Determination 3. Any studies
submitted to EPA that were not among the data collected for previous Regulatory Determination
cycles will be added to the data set evaluated for a future Regulatory Determination 5 evaluation.
EPA is aware of the presence of cobalt within the Vitamin B-12 complex as well as the Institute of
Medicine's Vitamine B-12 guidelines for various life-stage groupings including pregnancy and lactation
periods (IOM, 2006). There is an ongoing ATSDR update to the 2004 cobalt Toxicological Profile that
includes information on Vitamin B-12. The updated ATSDR Toxicological Profile was a factor in the
previous decision to delay the Regulatory Determination for Cobalt. When finalized, the updated
assessment will be considered for the next Regulatory Determination process.
Manganese
Comments Received on Manganese
Comment Excerpt from Commenter 75
ASDWA supports the inclusion of manganese on CCL 5. The health advisory for manganese (2004) is
outdated and needs to be updated in a timely manner. Research linking the secondary standard to
aesthetic issues has also been criticized, as the aesthetic issues are seen at levels much lower than
0.05 mg/L. ASDWA recommends that EPA conduct an updated risk assessment on manganese in a
timely manner, so that the manganese health effects data can catch up with the occurrence data
from the Fourth Unregulated Contaminant Rule (UCMR4) and regulatory decisions, i.e., a regulatory
determination can be made in a timely manner.
Several recent health effects studies have shown adverse neurotoxic effects of high levels of
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manganese in drinking water and many states have been taking action to address the contaminant.
For example, Massachusetts has undertaken an initiative to make its public water suppliers and their
customers more aware of the existing US EPA health advisory values for manganese and the health
implications of having exposures greater than those guidelines. This initiative included a monitoring
requirement to better understand the extent of manganese contamination. The initiative found a
significant number of samples had manganese concentrations greater than the US EPA lifetime Health
Advisory level of 0.3 mg/L. Sampling data indicated that approximately 35-40% of raw groundwater
samples and about 12-26% of finished water samples used by these public water suppliers exceed this
limit. Additionally, New Hampshire has recently adopted a state advisory of 0.1 mg/L for manganese
for protection of infants and has also adopted a state ambient groundwater quality standard of 0.3
mg/L. With numerous studies pointing to the negative impacts of high levels of manganese in drinking
water, ASDWA recommends that EPA evaluate the need to update the manganese health advisory
and make a regulatory determination.
Individual Response: Please see Discussion on Individual Chemical Contaminants. EPA agrees that
manganese should be listed on the CCL 5 and that the database for studies on both its health benefits
as a nutrient and its adverse neurodevelopmental impacts as a toxic agent has increased since the
Regulatory Determination decision to not regulate manganese in 2003. The Office of Water decision
at that time was based on a conclusion that the existing Secondary Maximum Contaminant Level
(SMCL) assessment would provide adequate protection when coupled with the 2003 Health Advisory
guideline that limited early life exposures to manganese through formula, and the lifetime drinking
water concentration to 0.3 mg/L and the ten-day exposure value to 1 mg/L.
The UCMR 4 monitoring data provide the occurrence data to support including manganese on CCL 5.
A number of states, countries, and the World Health Organization (WHO) recently updated their
manganese risk assessments and guidelines based on health effects data published after the
Regulatory Determination 1 manganese decision. EPA will consider these data when evaluating
manganese under the Regulatory Determination 5 process.
Comment Excerpt from Commenter 82
I. Introduction
On behalf of the Manganese Interest Group ("MIG"), we are pleased to submit the following
comments concerning the U.S. Environmental Protection Agency's ("EPA" or "Agency") notice
concerning Drinking Water Contaminant Candidate List 5 - Draft ("CCL 5"). See 86 Fed. Reg. 37,948
(July 19, 2021) (referring to docket EPA-HQ-OW2018-0594) (hereinafter "the Notice"). MIG is an ad
hoc coalition of trade associations and companies interested in the scientifically sound evaluation and
regulation of manganese compounds. MIG's members include steel producers, metalworkers,
chemical manufacturers, ferroalloy producers, and other like-minded stakeholders, most of which
operate in the United States. [FN 1: Group members include: the American Iron and Steel Institute,
the Steel Manufacturers Association, the Specialty Steel Industry of North America, the International
Manganese Institute, the National Slag Association, Afton Chemical Corporation, American Zinc
Recycling, Cleveland-Cliffs, Inc., Eramet Marietta, Inc., New Castle Stainless Plate LLC, North American
Stainless, Nucor Steel, S.H. Bell Company, and U.S. Steel]
MIG's principal interest in the Notice is the scientific merit of maintaining manganese on the CCL 5. As
the Agency has openly acknowledged in other regulatory settings, manganese is an essential nutrient
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that is subject to strict homeostatic control in the human body. Large amounts of manganese are
naturally present in many foods consumed as a part of a normal diet, so manganese in drinking water
at the levels typically measured is unlikely to add materially to the normal daily ingestion of
manganese from diet. Against this backdrop, the best available peer-reviewed science does not
support maintaining manganese on the CCL 5.
A validated human physiologically-based pharmacokinetic ("PBPK") model that EPA is primarily
responsible for developing has very recently been applied specifically to address EPA's main concern
about manganese in drinking water - namely, whether manganese in drinking water might lead to
developmental impacts in children. The relevant citation is Yoon, M., et al., "Assessing children's
exposure to manganese in drinking water using a PBPK model," Toxicology and Applied Pharmacology
380 (2019) 114695 (hereafter "Yoon 2019"). The Yoon 2019 paper states, "[t]hese simulations
indicate that drinking-water Mn at levels commonly encountered is expected to have minimal effect
on globus pallidus Mn concentrations in very young children through age 18" (referring to Figure 6).
The stated conclusion is based on an "expanded Mn PBPK model" that
describes age-dependent Mn homeostasis at dietary steady state, introduces
environmentally relevant inhalation and drinking water exposure conditions, and
accounts for differences in oral bioavailability of Mn for infants ingesting breast milk,
formula milk, or drinking water. This biologically-based model provides internal dose
information for children exposed by both inhalation and drinking-water and allows a
better understanding of the question whether there is age-related sensitivity to Mn
exposure via drinking water. Based on the results of the model, infants and children are
not expected to be at greater exposure than adults to Mn in drinking water.
Accordingly, MIG respectfully requests that manganese be deleted from the CCL 5. MIG appreciates
the opportunity to provide these comments.
II. EPA Has Long Recognized the Importance of PBPK Models for Risk Assessment,
Particularly for Essential Metals Such as Manganese
EPA has long recognized the potential importance of PBPK models to risk assessment [FN 2: See
"Approaches for the Application of Physiologically Based Pharmacokinetic (PBPK) Models and
Supporting Data in Risk Assessment," (EPA/600/R-05/043F) (2006) available at http://epa.gov/ncea.].
PBPK models consist of a series of mathematical representations of biological tissues and
physiological processes in the body that simulate the absorption, distribution, metabolism, and
excretion of chemicals that enter the body. PBPK models are designed to estimate how much of a
chemical reaches target tissues (i.e., the internal dose) from a particular level of exposure to that
chemical (i.e., an administered dose). The choice of an internal dose metric (sometimes called the
biologically effective dose) replaces the administered dose in the derivation of the quantitative dose-
response relationship, with the intent of reducing the uncertainty inherent in risk assessments based
on an applied dose (i.e., exposure level). This reduction in uncertainty and the improved scientific
basis for the dose-response value are the main advantages of PBPK models. PBPK models reduce
uncertainty and improve the scientific basis for determining the relationship among: (a) exposure to
the substance of interest; (b) dose to target tissues; and (c) biological response, i.e., toxicity. PBPK
models are typically used for interspecies extrapolation, estimating intraspecies variability, route-to-
route extrapolation, and duration of exposure adjustment in the risk assessment by means of
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chemical-specific adjustment factors rather than traditional uncertainty factors. [FN 3: Id.]
In the case of manganese, EPA had the foresight to mandate the generation of the data necessary to
develop human PBPK models as part of the registration testing program for the manganese-based
octane-enhancing fuel additive known as mmt® [FN4: mmt® is a registered trademark owned by
Afton Chemical Corporation.]. As explained by several EPA scientists in a paper published in 2018, the
test rule for mmt addressed a wide range of issues adding uncertainty for the risk assessment of
manganese:
Among the uncertainties identified were: the chemical forms of Mn emitted in
automotive exhaust; the relative toxicity of different Mn species; the potential for
exposure among sensitive subpopulations including females, the young and the elderly;
differences in sensitivity between test species and humans; differences between
inhalation and oral exposures; and the influence of dose rate and exposure duration on
tissue manganese accumulation. [FN5: Smith, D., et al., Manganese Testing Under a
Clean Air Act Test Rule and the Application of Resultant Data in Risk Assessment,
Neurotoxicology. 2018 January; 64: 177-184.]
As these same authors explained in their paper, "It was anticipated that development of specific sets
of pharmacokinetic (PK) information and models regarding Mn could help resolve many of the
identified uncertainties and serve as the best foundation for available data integration." [FN6: Id.
(emphasis added).] The validated human PBPK model for manganese affords EPA a clear opportunity
to integrate the available scientific data in the best possible way, just as EPA hoped would ultimately
occur when it developed and imposed the mmt registration test rule more than two decades ago. As
reflected in Attachment 1 to these comments, EPA's registration test rule for mmt has resulted in not
less than 45 publications in the peer-reviewed scientific literature, the culmination of which is a
validated human PBPK model for manganese.
III. EPA Must Rely on the Best Available Science for All Aspects of the Safe Drinking Water Act
Program
EPA is obligated to rely upon the best available science for any of its decisions relating to the CCL 5
[FN7: 42 U.S.C. § 300g-l(b)(3)(A).] EPA's proposal makes plain that it relies on the 2019 Health Canada
drinking water assessment for manganese as the basis for the Agency's manganese proposal [FN9:
Guidelines for Canadian Drinking Water Quality, Guideline Technical Document, Manganese, Health
Canada (May 2019) (hereafter "Canadian Manganese Assessment")][FN8: See Technical Support
Document for the Fifth Contaminant Candidate List (CCL 5) - Contaminant Information Sheets, p. A-
522, EPA 815-R-21-006 (July 2021). [FN9: Guidelines for Canadian Drinking Water Quality, Guideline
Technical Document, Manganese, Health Canada (May 2019) (hereafter "Canadian Manganese
Assessment")] Reliance upon the Canadian Manganese Assessment is unwarranted, however,
because it does not meet the "best available science" standard.
First, although Health Canada acknowledged the existence of the manganese PBPK models in its
assessment, Health Canada opted not to apply them in any respect, apparently based on the
misguided understanding that the manganese PBPK models have not been validated [FN10: Id., p. 47
("Although the model can be used to estimate manganese concentrations in brain tissue, such
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simulations have not been validated in humans.").]. In fact, the manganese PBPK models have been
validated a number of times, including the human manganese PBPK models [FN11: See Ramoju, S.P.,
et al., "The application of PBPK models in estimating human brain tissue manganese concentrations/'
Neurotoxicology 58 (2017) 226-237 (Figure 2); Gentry, P.R., et al., "A tissue dose-based comparative
exposure assessment of manganese using physiologically based pharmacokinetic modeling - The
importance of homeostatic control for an essential metal," Toxicology and Applied Pharmacology 322
(2017) 27-40 (Figures 1-5); Schroeter, J.D., et al., "Analysis of tracer kinetics and target tissue
dosimetry in monkeys and humans with multi-route physiologically-based pharmacokinetic models,"
Toxicological Sciences 120(2) (2011) 481-498. The Yoon 2019 paper also includes validation as
follows: "[A]II the simulated brain concentrations in the globus pallidus region were within the range
observed in human cadavers" and "[t]he age-profiles of whole-blood Mn concentrations are
consistent with the reported human data."].
Second, the literature review completed by Health Canada does not include a number of key
references which were not yet available when Health Canada completed its assessment of the
scientific literature. As explained in more detail in the following section, the omitted references
directly address EPA's concerns about manganese in drinking water and the likelihood of any adverse
developmental impacts. As noted, these studies specifically incorporate drinking water as a
component of the validated PBPK models for manganese.
Finally, EPA has stated that it will use the Umbrella Quality Assurance Project Plan ("QAPP") for PBPK
Models (i.e., EPA ORD QAPP ID Number: B-0030740-QP-1-0) "as an internal QA Project Plan in support
of U.S. EPA's Human Health Risk Assessment ("HHRA") research plan." The documentation needed to
fulfill the QAPP for the manganese PBPK model can be provided to EPA upon request.
IV. An Updated Human PBPK Model for Manganese Confirms that Children Are Not
Susceptible to Brain Manganese Tissue Increases When Exposed to Concentrations of
Manganese Measured in Drinking Water
The Canadian Manganese Assessment does not address two important papers that have updated the
validated human PBPK model for manganese to include a drinking water component that now covers
children ranging in age from infants to 18 years. The two papers are:
1. Song, G., "Physiologically-based pharmacokinetic modeling suggests similar bioavailability of
Mn from diet and drinking water," Toxicology and Applied Pharmacology 359 (2018) 70-81;
and
2. Yoon 2019.
As both papers are open-source publications, the papers are included with these comments as
Attachments 2 and 3.
Of particular importance to EPA's Notice, the Yoon 2019 paper applies the human PBPK model for
manganese to cover the following exposure scenarios:
1. A male infant exclusively breast-fed for 6 months after birth;
2. A male infant exclusively formula-fed for 6 months after birth, assuming the average daily
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intake from formula powder of 1.145 mg Mn/day;
3. A male infant exclusively formula-fed for 6 months after birth, assuming the average daily
intake from formula powder of 0.05 mg Mn/day;
4. A 3-year-old male toddler;
5. A 10-year-old male child;
6. An 18-year-old male teenager;
7. A male adult;
8. A female adult; and
9. A pregnant female and a male fetus.
According to the authors, the simulations run with the updated human PBPK model indicate "that
drinking-water Mn at levels commonly encountered is expected to have minimal effect on globus
pallidus Mn concentrations in very young children through age 18." Figure 6 from Yoon 2019, which is
replicated below, clearly shows very little or no change in brain manganese concentrations for any
childhood life stage exposed to manganese concentrations in drinking water at or below 100 ng/liter.
According to EPA's own "occurrence data" for manganese, very few samples of drinking water in the
United States reach such a high level of manganese given that the 90th percentile measurement is
more than three-fold lower [FN12: Technical Support Document for the Draft Fifth Contaminant
Candidate List (CCL 5) - Contaminant Information Sheets, pp. A521-524.]. [Figure 6: see docket ID
0082]
For very young children, moreover, the authors observe, "The PBPK modeling analysis strongly
indicated that the apparent difference in uptake in neonates is not due to immature homeostatic
mechanisms as previously inferred from earlier studies (Ballatori et al., 1987; Keen et al., 1986) but
rather the need to sequester Mn to build up tissue levels."
The authors of Yoon 2019 ultimately conclude: "Simulations with this expanded multi-dose route,
multi-age model structure indicate that the effect of adding drinking-water exposure along with
dietary intake and ambient air inhalation on tissue Mn concentrations in children is not expected to
be any greater than the effects in adults, even at drinking-water concentrations approximately twice
the Lifetime Health Advisory value set by the USEPA."
MIG strongly encourages EPA to consider this important new scientific information before the Agency
makes any final decisions concerning the CCL 5.
V. Conclusion
As explained in these comments, the best available science does not support maintaining manganese
on the CCL 5. EPA's chemical contaminants screening process inappropriately relies on the 2019
Health Canada drinking water assessment. Manganese would not have been included on the CCL 5 if
EPA's chemical contaminants screening process had appropriately relied on the best available science,
specifically the use of the validated human PBPK model for manganese updated to include a drinking
water component. Accordingly, MIG respectfully requests that EPA delete manganese from the CCL 5.
MIG very much appreciates the opportunity to provide comment on EPA's proposed CCL 5.
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Comments Received on Manganese
Individual Response: Please see Discussion on Individual Chemical Contaminants. EPA respectfully
disagrees with the Manganese Interest Group's conclusion that the available science does not support
maintaining manganese on the CCL 5.
EPA is aware of the substantial number of post-CCL 4 toxicological and epidemiological publications
on manganese that identified a number of different adverse health outcomes. EPA identified the
Yoon, Young, and Song publications as part of the rapid systematic literature review conducted to
support development of CCL 5 [See Chapter 4 Classification of PCCL Chemicals to Select the CCL of the
Final CCL 5 Chemical Technical Support Document (USEPA, 2022a)]. The Yoon paper is one of several
pharmacokinetic models for manganese published after the current 2003 Health Advisory was issued.
EPA agrees that physiologically-based pharmacokinetic (PBPK) models can be useful, although not
necessary, in conducting a risk assessment and will further evaluate the available literature for
manganese during the Regulatory Determination 5 process. Both the Young and Song papers are
included in the recent Canadian and World Health Organization updates to their manganese
assessments. EPA will evaluate the available manganese health effects literature, including the recent
publications, as part of the Regulatory Determination 5 process.
Per the CCL 5 process, manganese was included on the CCL 5 because available data from UCMR 4
indicate that manganese is known to occur in public water systems and that the available health data
indicate it may require drinking water regulation. EPA therefore maintains that its decision to include
manganese on the CCL 5 is justified.
Tungsten
Comments Received on Tungsten
Comment Excerpt from Commenter 68
Dear Sir/Madam - ITIA appreciates the Agency's dedication to the ongoing evaluation of drinking
water standards to protect human health. On 19 July 2021 the US EPA released the Drinking Water
Contaminant Candidate List 5-Draft where tungsten (CASN 7440-33-7; DTXSID8052481) is included.
We are aware the Final Hazard Quotient (HQ) for tungsten is calculated using the Reference Dose
(RfD) listed in the 2015 Provisional Peer-Reviewed Toxicity Values (PPRTV) for Soluble Tungsten
Compounds (US EPA, 2015). Since the PPRTV was prepared, new data has become available that we
believe warrants a revision of the Tungsten Contaminant Information Sheet to reflect a RfD based on
more up to date toxicity data. This new data generated by US NTP on sodium tungstate determined
that the target organ in female and male rats and mice is the kidney instead of the glomerular
stomach. Please review the attached information for additional details on this matter.
It is the hope of ITIA that further discussions can be held and a consensus reached with regard to the
revision of the provisional oral -RfD for soluble tungsten compounds.
Individual Response: Please see Discussion on Individual Chemical Contaminants. While the National
Toxicology Program (NTP) provides valuable data on health effects, including potential dose-response
data, these technical reports do not include derivation of Reference Doses or Cancer Slope Factors
used to develop Health Reference Levels for the CCL 5 Classification process [See Chapter 4
Classification of PCCL Chemicals to Select the CCL of the Final CCL 5 Chemical Technical Support
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Document (USEPA, 2022a)]. During the Regulatory Determination process, EPA will have the
opportunity to examine tungsten's entire toxicity database, including recently published toxicological
information such as the NTP Technical Report on the Toxicology and Carcinogenesis Studies of Sodium
Tungstate Dihydrate (CASRN10213-10-2) in Sprague Dawley (Hsd:Sprague Dawley® SD®) Rats and
B6C3F1/N Mice (Drinking Water Studies) (NTP, 2021).
Vanadium
Comments Received on Vanadium
Comment Excerpt from Commenter 86
September 17, 2021
Submitted via http://www.regulations.gov
Water Docket
U.S. Environmental Protection Agency
Mail Code 28221T
1200 Pennsylvania Avenue, NW Washington, DC 20460
ATTN: The Honorable Radhika Fox, Assistant Administrator for the Office of Water
Re: Docket No. EPA-HQ-OW-2018-0594, Notice of Availability, Request for Comments, Draft Drinking
Water Contaminant List 5; 86 Fed. Reg. 37948 (July 19, 2021)
Dear Assistant Administrator Fox:
The Vanadium Producers and Reclaimers Association (VPRA) would like to thank you for the
opportunity to comment on the Environmental Protection Agency's (EPA's) fifth Contaminant
Candidate List (CCL 5). VPRA is the not-for-profit corporation that is representing the domestic
vanadium industry in the United States and is the primary industry stakeholder expert on vanadium
compounds. However, our members operate in a highly competitive international environment, and
our resources are modest. Specifically, VPRA and its 3 producing members qualify as small businesses
with from 9 to no more than 250 employees. Vanadium is among the 35 minerals and metals the U.S.
Geological Survey has deemed critical to the United States. The following industry website contains
information on the strategic defense uses of vanadium as well as environmentally beneficial
applications: http://vanitec.org/vanadium/using-vanadium
VPRA finds that the scientific basis for inclusion of vanadium on the CCL 5 is flawed and recommends
removing it from CCL 5 listing under the Safe Drinking Water Act (SDWA). First, the occurrence data
used by EPA to support vanadium's listing in CCL 5 are not relevant due to lack of consideration on
the forms of vanadium to which the public may be exposed. Second, the health effects data available
on vanadium at this time are inappropriate for fully understanding the potential risks, if any,
associated with vanadium species. We think that EPA's information on vanadium occurrence and
toxicity does not meet the criteria for inclusion on the Contaminant Candidate List (CCL) and the
historical retention of vanadium on this list should be discontinued until such time as these data gaps
can be appropriately addressed.
I. Background
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Pursuant to section 1412(b)(l)(B)(i) of the SDWA, as amended in 1996, EPA is required to publish a list
of contaminants(l) that are currently unregulated; (2) that are known or anticipated to occur in public
water systems; and (3) that may require regulation under the SDWA. SDWA section 1412(b)(1)
requires EPA to make determinations every five years on whether to regulate at least five
contaminants from the CCL SDWA also 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
• The regulation of such contaminant presents a meaningful opportunity for health risk
reduction for persons served by public water systems.
VPRA thinks that CCL listings should exhibit strong potential to meet these criteria and that EPA's case
for vanadium's placement on the CCL is weak. On July 19, 2021, EPA published the fifth CCL since the
issuance of the SDWA amendments of 1996. Although EPA has included vanadium on every CCL list
since 1998 and is proposing to retain vanadium in CCL 5, we do not think EPA has ever established
that vanadium has the potential to meet the criteria for regulation above. These comments explain
why it is reasonable and appropriate for EPA to remove vanadium from the proposed CCL 5 list.
The July 19th Federal Register Notice states that the SDWA directs EPA 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 Federal
Register Notice also states that the draft CCL 5 list utilizes the best available data to characterize the
occurrence and adverse health risks a chemical may pose from drinking water exposure (86 Fed. Reg.
at 37951).
Due to data deficiencies and the utilization of inaccurate and/or low confidence information,
vanadium cannot and should not be among the contaminants considered as the greatest public health
concern. EPA has not utilized the best available data to determine either vanadium's occurrence or
adverse health risks and, therefore, EPA cannot conclude that vanadium is a concern for drinking
water or a national concern for which federal regulation may be appropriate or supportable.
II. Vanadium Chemistry Considerations are Not Factored into Occurrence Information
In developing regulations for chemical compounds containing vanadium in drinking water several
chemistry-based factors must be considered. Vanadium is a naturally occurring element and is the
20th most abundant element in the earth's crust. Like most metals, it does not occur in the native,
metallic form, but instead occurs naturally in about 65 different minerals. Notably, the most widely
toxicologically studied vanadium compound, vanadium pentoxide, V205, does not occur naturally
(with the one very rare exception of a volcano caldera in Siberia), and chemically reacts with water to
form a range of vanadium containing anions and cations, depending on the exact conditions of the
solution.
The aqueous chemistry of vanadium is complex as compared to other metals such as nickel or copper.
In simple solutions, not containing any other ligands, vanadium can occur as separate inorganic
species with four possible oxidation states (+2, +3, +4, +5) and nine different charges, including both
anions and cations. [FN1: Kelsall et al., Redox chemistry of H2S oxidation by the British Gas Stretford
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Comments Received on Vanadium
process part IV: V-S-H20 thermodynamics and aqueous vanadium reduction in alkaline solutions.
Journal of Applied Electrochemistry 23, 41-426, 1993. https://doi-org/10.1007/BF00707617.1 The
presence of other chemicals routinely used to treat public drinking water supplies (for example CI and
F compounds routinely added to water systems in the USA) only increases this complexity
There is evidence that the vanadium speciation can alter toxicity.[FN2: Roberts GK, Stout MD, Sayers
B, Fallacara DM, Hejtmancik MR, Waidyanatha S, Hooth MJ. 14-Day Toxicity Studies of Tetravalent
and Pentavalent Vanadium Compounds in Harlan Sprague Dawley Rats and B6C3F1/N Mice via
Drinking Water Exposure. Toxicol Rep. 2016; 3:531-538.
https://doi.Org/10.1016/j.toxrep.2016.05.001. Epub 2016 May 12. PMID: 28042531; PMCID:
PMC5193388. At the request of the Office of Water, the National Toxicology Program (NTP) is
investigating the toxicity of solutions of sodium metavanadate and vanadyl sulfate and found
toxicological differences in mice. However, corresponding data on the speciation of vanadium
compounds present in US drinking water is, to the best of our knowledge, simply not available at this
time. Absent this and other information, EPA has not demonstrated that vanadium presents the
potential for a meaningful opportunity for health risk reduction for persons served by public water
systems.
For CCL 5, EPA uses data collected from the Unregulated Contaminant Monitoring Phase 3 rule
(UCMR3) where drinking water systems only measured total vanadium to score and rank vanadium.
As a result of UCMR3, extensive data on the occurrence of vanadium species (measured as total V)
were generated for water systems across the USA. VPRA believes that measuring total vanadium in
drinking water is inappropriate and this approach was used against our recommendation during
UCMR3. [FN3: https://www.regulations.gov/comment/EPA-HQ-OW-2009-0090-0059.] Specifically,
the UCMR3 data capture all of the various oxidation states of vanadium under a single "vanadium"
heading. EPA is inappropriately relying on the totality of occurrence data to grossly mischaracterize
all vanadium species in drinking water as presenting a public health concern. It is not possible based
on this data set for EPA to know the forms of vanadium that occur in drinking water or whether any
forms of vanadium that may have an adverse effect on public health are "known to occur" in drinking
water.
III. Toxicity Data Are Lacking to Support a Continued CCL Listing
While there are many safety studies of oral exposure to vanadium species available in literature, a
close assessment of nearly all of them will show that they are inadequate for that purpose. The
available studies have significant limitations compared to the traditional designs for studies
conducted to support safety evaluations. The vanadium studies often don't use standard designs or
methods, leading to an inability to make comparisons between data sets. In most available studies,
very limited endpoints have been evaluated, often only a few, which makes comparison of the effects
to those reported in other studies impossible. Other deficiencies include that the test compound is
often not sourced or analyzed, therefore the vanadium concentrations already present in food or
water are not measured making the actual dose uncertain. As a result, it is not possible to establish
the form of vanadium that may have an adverse effect on the health of persons with the current data
set. These weaknesses in safety studies have resulted in divergent approaches to the derivation of an
oral reference dose for vanadium compounds that can span two orders of magnitude.
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Comments Received on Vanadium
For CCL 5, EPA is using the outdated Provisional Peer-Reviewed Toxicity Value (PPRTV) developed by
EPA in 2009. [FN4: U.S. EPA, Provisional Peer-Reviewed Toxicity Values for Vanadium and Its Soluble
Inorganic Compounds Other Than Vanadium Pentoxide (CASRN 7440-62-2 and Others) Derivation of
Subchronic and Chronic Oral RfDs, EPA/690/R-09/070F Final 9-30-2009.] The toxicity value is orders of
magnitude different from a more recent assessment of vanadium conducted by the Agency for Toxic
Substances and Disease Registry (ATSDR) and is too uncertain to be utilized for the CCL listing. In fact,
the PPRTV document acknowledges that the key study used (Boscolo et al., 1994) has low confidence,
so much so that EPA has applied a 3000 fold uncertainty factor in total, the greatest amount that can
be used in the development of a reference dose. [FN5: Boscolo, P; Carmignani, M; Volpe, AR; Felaco,
M; Del Rosso, G; Porcelli, G; Giuliano, G. (1994). Renal toxicity and arterial hypertension in rats
chronically exposed to vanadate. Occup Environ Med 51: 500-503.
http://dx.doi.Org/10.1136/oem.51.7.500.1
In a more recent review of vanadium safety, ATSDR determined the Boscolo 1994 study should not be
utilized for development of a benchmark, specifically noting the effect in Boscolo was not consistently
observed in other animal studies or in a study of healthy adults (Fawcett et al. 1997). [FN6: Fawcett
JP, Farquhar SJ, Walker RJ, Thou T, Lowe G, Goulding A. The effect of oral vanadyl sulfate on body
composition and performance in weight-training athletes. Int J Sport Nutr. 1996 Dec; 6(4):382-90.
http://doi.Org/10.1123/ijsn.6.4.382. PMID: 8953340.] As a result, EPA's reliance on the PPRTV is
insufficient to establish a substantial likelihood that forms of vanadium which may have an adverse
effect on public health will occur in public water systems with a frequency and at levels of public
health concern. We also want to note that food is the primary route of exposure for the general
population; with estimates of dietary vanadium intake ranging from 0.09 to 0.34 ng/kg/day in adults.
[FN7: U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease
Registry. Toxicological Profile for Vanadium, September 2012. Page 31.] These estimated
concentrations in daily food ingestion far exceed the toxicity benchmarks EPA is utilizing to develop
the CCL 5 list.
EPA is aware of the shortcomings of the safety database on vanadium. At the Office of Water's
request, the NTP is currently conducting toxicity studies on vanadyl sulfate (+4) and sodium
metavanadate (+5) to fill identified gaps in science. These draft NTP reports have yet to be released.
The utility of these studies will be limited without being able to correlate the results to speciated
vanadium concentrations in drinking water. At EPA's Office of Water's request, the IRIS program also
is conducting a review of vanadium and VPRA has raised similar concerns on the approach in
comments. [FN8: https://www.regulations.gov/comment/EPA-HQ-ORD-2020-0183-0014.] [FN9:
https://www.regulations.gov/comment/EPA-HQ-ORD-2020-0183-0027.] VPRA does not believe it is
appropriate for EPA to continue to include vanadium as part of the SDWA regulatory process when
EPA is not aware if any vanadium species are present in drinking water that present a public health
concern, and in light of the significant uncertainties and low confidence in the toxicity information
currently available.
IV. Conclusions
VPRA believes that vanadium does not meet the criteria for inclusion on the CCL. We recommend
removing vanadium from inclusion on CCL 5 until data are available on the form of vanadium to which
humans are exposed through drinking water and the toxicity of that form is understood.
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Comments Received on Vanadium
It would be beneficial for EPA to carry out a program of research to identify the vanadium species
actually present in drinking water and establish that they meet the CCL listing criteria as an important
step toward correlating available toxicological data with the predominant vanadium compound the
American public is exposed to in drinking water. Our industry is in the formative stage of planning a
public workshop on the speciation and environmental fate of vanadium compounds and we would
welcome an expression of interest and support from your office.
Individual Response: Please see Discussion on Individual Chemical Contaminants. Other Drinking
Water Programs, and Other EPA Programs. Based upon the data collected for CCL 5, including
occurrence data collected for UCMR 3 and the available health assessments, EPA concludes that
vanadium is known or anticipated to occur in public water systems and may require drinking water
regulation and therefore meets the criteria for listing under the SDWA. EPA recognizes the value of
data on vanadium speciation, both in terms of potential differences in health effects resulting from
oral exposures and occurrence in water from public systems.
https://ntp.niehs.nih.gov/ntp/results/pubs/posters/roberts sot20190300.pdf
The critical study for the 2009 PPRTV assessment is described as a low confidence study by EPA's
Office of Research and Development in the PPRTV document, though the confidence in the database
is medium. The observed kidney toxicity endpoint selected as the critical effect is supported by a
subchronic study (Domingo et al., 1985) that serves as the basis for the Institute of Medicine (IOM)
Tolerable Upper Limit value (IOM, 2001). The PPRTV document includes a statement acknowledging
the corroborating evidence provided by the Domingo et al. (1985) study. EPA acknowledges that the
oxidation state of vanadium may influence the observed health effects. The exposure estimates in all
of the toxicity studies in the PPRTV were converted to equivalent vanadium doses for the purpose of
dose-response assessment since oral exposures to either vanadyl (+4) or vanadate (+5) result in
internal exposures to a mixture of vanadyl and vanadate complexes as a result of reduction/oxidation
(redox) reactions that occur in the gastrointestinal tract as well as in the blood and tissues. As a result
of these physiological interconversions, the PPRTV document states that there is no firm toxicological
basis for distinguishing dose-response relationships for these two forms given the currently available
data. As such, the PPRTV applies to soluble inorganic vanadyl (+4) and vanadate (+5) compounds
(other than vanadium pentoxide which is the subject of an IRIS review and separate PPRTV
document). UCMR monitoring provides high quality nationally representative drinking water data for
the water sector and EPA believes it was appropriately used in CCL 5 to evaluate the occurrence of
total vanadium.
EPA is aware that the National Toxicology Program (NTP) is currently conducting toxicity studies on
vanadyl sulfate (+4) and sodium metavanadate (+5) to fill data gaps.
https://ntp.niehs.nih.gov/ntp/results/pubs/posters/roberts sot20190300.pdfThis study will
contribute to the vanadium health effects database to be considered for the Regulatory
Determination Process and/or future CCL cycles. The Roberts et al. (2014) study cited by the
commenter was conducted in response to an EPA post Regulatory Determination 2 request to NTP to
examine whether there are differences in the dose-response and target tissues between the vanadyl
and vanadate ions. The authors concluded that there are potential differences in toxicity between
vanadyl sulfate and sodium metavanadate but recognized that further studies are needed to fully
understand the mechanisms of toxicity underlying these differences. With this information lacking,
EPA must rely on the currently available health assessments and monitoring data for vanadium.
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Comments Received on Vanadium
Additional health effects data for vanadium have become available since it was last considered
through the CCL process. Inclusion of Vanadium on the CCL 5 indicates that vanadium will be
considered for Regulatory Determination if both the occurrence and health effects data are adequate
to support guideline development.
Molybdenum
Comments Received on Molybdenum
Comment Excerpt from Commenter 104
The International Molybdenum Association is aware from the Federal Register Vol. 86 No. 135 of 19
July 2021, that molybdenum (CAS No. 7439-98-7) is included in the US-EPA Drinking Water Draft
Contaminant Candidate List 5. Molybdenum was also listed on CCL4 and CCL3, and was a substance
for which occurrence monitoring took place under the UCMR 3 between 2013-2015.
When commenting on the Draft CCL4 in 2015, IMOA listed a series of technical submissions which we
had already provided to US EPA Office of Water, to the attention of Dr. Joyce Donohue. (The list is
repeated overleaf). Since then, further studies and documentation have become available, as
summarized below:
A two-generation reproductive toxicity study of sodium molybdate, dihydrate administered in
drinking water or diet to Sprague-Dawley rats. Murray et al, 2019. Reproductive Toxicology 84
(2019) 75-92. https://doi.Org/10.1016/j.reprotox.2018.ll.004 . This Open Access peer-
reviewed publication was submitted by IMOA in 2019 to EPA OoW (Dr. Donohue).
A copy of the following very recent documentation can be made available upon request to IMOA:
In Vivo Micronucleus Assay of Sodium Molybdate Dihydrate by Oral Gavage in Sprague
Dawley Rats. CRL Study No. 01439003. OECD 474 guideline compliant GLP study, May 2021.
Oral (Diet) Developmental Toxicity Study of Sodium Molybdate Dihydrate in Rats, extending
the dose ranges of the earlier Tyl 2013 study by 2 and 3-fold. CRL Study No. 20222165. OECD
414 guideline compliant GLP study, June 2021
September 2021 Molybdenum Hazard identification and Risk Assessment Chemical Safety
Report (300+ pages) prepared for compliance with the EU REACH Regulation.
US ATSDR published its Toxicological Profile for Molybdenum in May 2020, downloadable from:
https://www.atsdr.cdc.gov/toxprofiles/tp212.pdf. Whilst largely an excellent document, worthy of
particular note is that IMOA disagrees with the application of the Modifying Factor of 3 used to derive
the intermediate oral Minimum Risk Level, and placed its concerns in writing to US ATSDR in
correspondence dated 24 March 2021, also copied to EPA (Drs. Betsy Behl & Joyce Donohue).
The available toxicity datasets (including the most recent above-indicated data), assessments, and
monitoring data, in IMOA's assessment do not warrant molybdenum remaining on the CCL list.
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Also noteworthy is that since 2011 the World Health Organisation Guidelines for Drinking Water
Quality, Fourth Edition no longer establishes a formal guideline value for molybdenum in drinking
water. Only for guidance purposes is a health-based value of 0.07 mg Mo/L indicated. The rationale
for not deriving a formal guidance value is indicated as: '(Molybdenum) occurs in drinking water at
concentrations well below those of health concern'. (Reference: pages 177 & 394 of The World Health
Organization Guidelines for Drinking-Water Quality, Fourth Edition, 2011. ISBN 978 92 4 154815 1).
Key documentation already provided to EPA OoW between 2011-2015:
Molybdenum Hazard Identification and Risk Assessment Report - 330 pages, (as prepared for
the EU REACH Regulation No. 1907) - (E-mailed on 30 April 2011 & 8 August 2011)
Final Report of GLP OECD protocol 408-compliant, sub-chronic 90-day oral repeated dose
toxicity study, using sodium molybdate - (E-mailed 15 November 2011)
Final Report of GLP OECD protocol 414-compliant Prenatal Developmental Toxicity study,
using sodium molybdate - (E-mailed 13 August 2013)
Links to Open Access peer-reviewed journal publications for both studies - (E-mailed on 11
May 2014 and 12 March 2015 respectively)
Copies of all the above are available upon request to IMOA.
Individual Response: Please see Discussion on Individual Chemical Contaminants. EPA appreciates the
materials submitted to the Office of Water and communications about ongoing research activities of
the International Molybdenum Association. The submitted publications that were published prior to
Regulatory Determination 4 were considered during the Regulatory Determination 4 process. The
available literature on molybdenum, including the publications provided and the final ATSDR
Toxicological Profile for Molybdenum described in the comment, will be reviewed and considered
during the Regulatory Determination 5 process.
Chemical Technical Support Documents
Agency Discussion on Chemical Technical Support Documents
Agency Topic Discussion:
EPA received multiple comments in support of continued improvement to CCL documentation, with
several commenters recommending specific steps to facilitate transparency and clear communication
of the CCL process. EPA appreciates this feedback and welcomes ways it can improve the public's
understanding of how drinking water contaminants are listed to the CCL.
In drafting the CCL 5 documents, EPA attempted to strike a balance between providing enough detail
to adequately describe the three-step selection process, while also being concise enough with
descriptions for the public to be able to review all published materials within the allotted review time.
As one commenter noted, however, there were still more than 1,300 pages of technical support
documentation for the public to review and evaluate within a 60-day comment period for the Draft
CCL 5 Federal Register Notice. EPA recognizes this user-side challenge and will consider reducing the
overall length of supporting materials and/or providing a longer 90-day comment period for future
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draft CCLs.
One notable change to CCL 5 compared to previous CCLs is to the overall support document
organization; unlike with the CCL 3 and CCL 4 technical support documents that contained
descriptions for the three process steps (i.e., Building the Universe, Screening, and
Classification/Selection) across multiple documents, CCL 5 consolidated the descriptions for these
steps under single documents for both the chemical and microbial processes. EPA believes this
streamlined approach improves users' accessibility to the published materials and better
communicates how Steps 1-3 of the CCL process function in their sequential order.
Two commenters requested that EPA expand on the process used to "off-ramp" contaminants that
appeared previously for CCL 4 but were not listed on CCL 5. Out of the 97 chemicals or chemical
groups listed on CCL 4, there were 67 not listed onto CCL 5; below is a summary for those 67
chemicals (a more detailed table is provided in Appendix O of the Final CCL 5 Chemical Technical
Support Document (USEPA, 2022a):
• 45 chemicals from CCL 4 failed to qualify for the PCCL 5 based on screening points calculated
below the inclusion threshold during Step 2 of the process (see Chapter 3 of the Final CCL 5
Chemical Technical Support Document).
• 11 chemicals from CCL 4 that qualified for the PCCL 5 were determined as "not list" decisions
by EPA's chemical evaluators during Step 3 of the process (see Section 4.5 of the Final CCL 5
Chemical Technical Support Document).
• 8 chemicals from CCL 4 that qualified for the PCCL 5 were removed from consideration due to
their pending review status under Regulatory Determination 4 (see Section 3.7.1 of the Final
CCL 5 Chemical Technical Support Document).
• 2 chemicals from CCL 4 that qualified for the PCCL 5 were removed from consideration based
on their status as cancelled, not-persistent pesticides (see Section 3.7.2 of the Final CCL 5
Chemical Technical Support Document).
EPA also received one comment in support of the improvements made for the Contaminant
Information Sheets (CIS) for the CCL 5 and another comment stating concerns about "under-
representation of data for contaminants with isomers" on the CIS.
EPA developed a chemical CIS, a concise 4-page profile, for each chemical on the PCCL 5 that was
evaluated by the chemical evaluators to assist them in making listing recommendations for the CCL 5.
Each CCL 5 chemical CIS presents a chemical's health and occurrence data gathered from primary and
supplemental data sources, health and occurrence statistical measures and attribute scores, usage
information, identity information (i.e., chemical name, CASRN, and DTXSID), past CCL status, CCL 5
public nomination status, and past negative regulatory determination information.
For CCL 5, EPA improved upon the CCL 3 and CCL 4 CISs by modifying the CIS format to make the
Chemical data easier to use and interpret. EPA utilized principles of effective data visualization for the
new CIS design, such as: incorporating visual elements such as color and shading, simplifying data
tables, and emphasizing key areas most important to the chemical evaluators and stakeholders.
Additional improvements included a simplified CIS Key, an annotated graphic illustration, to assist
with interpretation of the updated CIS design and a reference page for each CIS that contains full
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Agency Discussion on Chemical Technical Support Documents
references for bracketed citations located on the CIS.
EPA will continue to improve the CIS design and chemical data presentation for future CCL cycles.
Comments Received on Chemical Technical Support Documents
Comment Excerpt from Commenter 55
However, to me, the more concerning point is that there seems to be under-representation of data
for contaminants with isomers. I'll use cypermethrin as an example and point specifically to (what I
consider) the misuse of the estimated annual USGS pesticide application use data. According to the
data presented in the Contaminant Information Sheets, in 2016, there were 14 states with estimated
cypermethrin application. However, when one goes to the 2016 USGS Pesticide Use Data
(https://water.usgs.gov/nawqa/pnsp/usage/maps/county-level/), there's more to the story. While
what is labelled as cypermethrin was used in 14 states, alpha-cypermethrin is used in 20 states, and
zeta-cypermethrin is used in 45 states. However, both alpha-cypermethrin and zeta-cypermethrin are
conspicuously absent from the PCCL, presumably because they aren't considered distinct enough for
their own consideration - after all, cypermethrin often contains one or both of these isomers. But if
that's the case, data on those isomers should certainly be included with cypermethrin. The estimated
amount applied per year is also way underestimated if all isomers are considered. The value given in
the CIS form for cypermethrin matches the low estimate from USGS for only "cypermethrin": 23,804
lb/year. In reality, when one looks at all three isomers ("cypermethrin", "alpha cypermethrin", "zeta
cypermethrin") in the USGS report, even by the low estimate, there are an estimated 180,600 lb
applied per year. That's a whole order of magnitude. I didn't even get a chance to look at the NAWQA
occurrence data for cypermethrin, but in the final CCL, I'd like to see some confirmation that the
NAWQA data includes applicable isomers. As it stands, prevalence and magnitude are under-reported
for cypermethrin and likely several other contaminants that consist of multiple isomers.
It seems the methodological problem is resulting from each isomer having its own DTXSID. But though
they have different DTXSIDs, it's clear that these isomers should be taken into consideration. So in
conclusion, there should be (1) some reconsideration of how to combine data on isomers, since those
contaminants' occurrence data are otherwise under-reported; and beyond that, (2) some
consideration on how to consider functional analogs that themselves lack important data.
And again, while I only touched briefly on one contaminant (cypermethrin) in one functional group
(pyrethroids), there are other contaminant groups, especially some other pesticides such as triazines,
that EPA should consider in terms of the issues of isomerism and functional groupings.
Individual Response: Please see Discussion on Chemical Technical Support Documents.
EPA has also updated the Contaminant Information Sheets (CISs) for cypermethrin and four other
contaminants to clarify which data entries are associated with other forms of the contaminant; the
other contaminant include, lithium, manganese, propiconazole, and vanadium (please see Technical
Support Document for the Final Fifth Contaminant List (CCL 5) - Contaminant Information Sheets,
hereafter referred to as the Final CCL 5 CIS Technical Support Document (USEPA, 2022b).
Comment Excerpt from Commenter 60
As a regular user of water, like many other Americans, it is imperative that the EPA continue to
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October 2022
Comments Received on Chemical Technical Support Documents
generate the Containment Candidate List (CCL) which the Safe Drinking Water Act (SDWA) mandates
is published every five years. After reviewing the lists of different contaminants in our water, the EPA
has done a thorough job of listing and also providing explanations to the public of what these
contaminants are so it is easier for the public to understand.
The list can be intimidating to some and also has the ability to put fear of drinking water into others.
Though I understand that simplifying most of the list for the general public is difficult, there should be
a way to provide a more general breakdown of the list to everyone. Unfortunately in the U.S. there
are areas where water contamination is terrible, thankfully this is not the norm.
I appreciate the publishing of this list since 1996 and hope the EPA continues to do so, in hopes that
efforts are made to continue to make our water safer for everyone. I propose the EPA make a more
easily digestible document for the public, maybe one with pictures and explanations so all can learn
from it and have any fears set aside. Thank you.
Individual Response: Please see Discussion on Chemical Technical Support Documents. For general
information on CCL and the process, please visit the EPA CCL website.
Comment Excerpt from Commenter 71
In this same vein, AMWA requests that EPA clarify the process for removing a contaminant from the
CCL. In a 2016 report from the Science Advisory Board (SAB) reviewing the agency's draft CCL 4, the
SAB requested that EPA clearly describe the "off-ramp" process for removing contaminants from one
CCL to another. This process was unclear to the SAB and continues to be unclear to AMWA. If no
process currently exists, AMWA urges EPA, with the help of the SAB, to develop a clear and concise
protocol to help the agency further prioritize contaminants on future CCLs. A process of this type is
critical to maintaining a more concise CCL, which the agency could use more effectively for prioritizing
research. If this process already exists and was used for CCL 5, AMWA requests that EPA make this
more apparent by including the relevant documents within the docket.
Correspondingly, AMWA requests that EPA provide a simple one or two-page document highlighting
any changes from the previous CCL. Most importantly, this document should contain information on
which chemicals were carried over, removed, and added. Currently, to determine this, a member of
the public must dig through supplemental documents within the docket. AMWA also suggests that
EPA include a simple explanation as to why a substance was removed or retained. Including a single
document explaining which chemicals were added or removed would improve transparency and
clarity for the public.
Individual Response: Please see Discussion on Chemical Technical Support Documents and Other
Drinking Water Programs. The commenter mentions an "off-ramp" process for removing
contaminants from one CCL to another. The CCL 5 was developed using the best available occurrence
and health effects data at the time and utilizing an improved process. Based on that data and the
process used for CCL 5, some contaminants from previous CCL were also listed on CCL 5 while other
were not. In regard to the commenter's statement related to the prioritization of the CCL, EPA has
provided a table that includes the data availability of occurrence data and health effects data for the
CCL chemical contaminants, as of the date by which each chemical was evaluated for placement on
the Draft CCL 5 (February to July 2020), is presented in Exhibit 4.
Comment Excerpt from Commenter 71
AMWA thanks EPA for including a table within the Federal Register notice that summarizes the
available occurrence data, health assessments, and analytical methods for each CCL 5 contaminant.
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Comments Received on Chemical Technical Support Documents
AMWA encourages EPA to show similar documentation for the ongoing state of prioritization for the
contaminants included in the CCL. This documentation might be as simple as stating a contaminant is
currently a "high," "low," or "medium" priority and including the agency's rationale behind the
characterization. The association also suggests that EPA develop similar documentation on the state
of the research for each contaminant. AMWA encourages the agency to provide this information
online and to update this information regularly outside of the standard CCL publication within the
Federal Register
Individual Response: Please see Discussion on Chemical Technical Support Documents and Other
Drinking Water Programs. In developing CCL 5, EPA purposely avoided establishing a prioritization
schema for the listed contaminants; rather, the determination regulatory priorities for drinking water
contaminants fall within the scope of EPA's Regulatory Determination programs, which follows the
CCL listing process.
Comment Excerpt from Commenter 75
ASDWA supports the process EPA used to develop CCL 5. The work the Agency completed to profile
and review thousands of contaminants is appreciated. ASDWA supports the approach of not
automatically carrying over contaminants from CCL 4 to CCL 5. However, ASDWA recommends that
EPA provide further details on why contaminants from CCL 4 were not also listed on CCL 5 when no
regulatory determination was made. For example, did new research come to light on the
contaminant's occurrence or health effects? Did another EPA program address this contaminant
making it less of a threat for drinking water sources? ASDWA recommends that EPA develop a
summary for the final CCL 5 for the 68 contaminants listed on CCL 4 but not listed on draft CCL 5. A
chart or table with some basic explanatory text would suffice. EPA's transparency in this
determination process is appreciated and especially helpful for state programs that may be
monitoring and tracking emerging drinking water contaminants.
Individual Response: Please see Discussion on Chemical Technical Support Documents.
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Comments Received on Chemical Technical Support Documents
Comment Excerpt from Commenter 77
[AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.]
Contaminant Information Sheets
The EPA Technical support document, "Technical Support Document for the Draft Fifth Contaminant
Candidate List (CCL 5) - Contaminant Information Sheets." represents a substantial body of
background research. This document is, in many ways, central to EPA's efforts to assure that the CCL
process is transparent to the public and interested stakeholders. AWWA commends the Agency for
continuing to include these information sheets in the CCL docket and on its efforts to improve on
previous CCL contaminant information sheets. [FN13: EPA. 2008. Contaminant Information Sheets for
the PCCL Chemicals Considered for CCL 3. EPA-HQ-OW-2007-1189-0043.] [FN14: EPA. 2015.
Contaminant Information Sheets (CISs) for the Draft Fourth Preliminary Contaminant Candidate List
(PCCL 4) Nominated Contaminants. EPA 815-R-15-003.] [FN15: EPA. 2016. Contaminant Information
Sheets (CISs) for the Final Fourth Contaminant Candidate List (CCL 4). EPA 815-R-16-003.] The
improvements to the formatting of the sheets for CCL 5 facilitate stakeholder review of EPA's use of
available data.
The information sheets also set the stage for EPA to elevate the influential aspects of the SDWA
decision-making processes in the CCL preamble more clearly:
1. The role of changing assumptions in setting health reference levels
2. Influential data gaps in the CCL process
Individual Response: Please see Discussion on Chemical Technical Support Documents.
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Comments Received on Chemical Technical Support Documents
Comment Excerpt from Commenter 77
Transparency
EPA has a duty to transparently present the evidentiary basis for its decision-making not only as a
matter of sound government but also in order to comply with Executive Orders and statutory
requirements. [FN16: Presidential Memorandum. 2021. Memorandum on Restoring Trust in
Government Through Scientific Integrity and Evidence-Based Policymaking.] [FN17: OMB. 2002.
Guidelines for Ensuring and Maximizing the Quality, Objectivity, Utility, and Integrity of Information
Disseminated by Federal Agencies; Republication.] This duty applies to influential documents, like the
CCL, as well as formal rulemakings.
The Draft CCL 5 Federal Register notice docket is much more concise and focused than many EPA
dockets (in large part due to the organization provided by the chemical information sheets). That the
CCL 5 universe is more than three times larger than the CCL 3 universe dataset illustrates the growing
need for of a concise summary. [FN18: EPA. 2008. Contaminant Candidate List 3 Chemicals:
Identifying the Universe. EPA 815-R-08-002. EPA-HQ-OW-2007-1189-0037.] Even so, there are more
than 1,300 pages of technical support documentation for the public to review and evaluate within a
60-day comment period. It is not clear from the contaminants listed and the information provided in
the Draft CCL 5 Federal Register notice and technical support documents that EPA fully explained how
it created the Draft CCL 5. This is not a new challenge. In reviewing the draft CCL 3, the Science
Advisory Board observed that the Agency made judgements within the CCL 3 process that were not
readily apparent in CCL process documentation. [FN19: SAB. 2009. SAB Advisory on EPA's Draft Third
Drinking Water Contaminant Candidate List (CCL3).]
Individual Response: Please see Discussion on Chemical Technical Support Documents.
Microbial Screening Process/Criteria
Agency Discussion on Microbial Screening Process/Criteria
Agency Topic Discussion:
The CCL microbial process consists of 12 exclusionary screening criteria developed during CCL 3 and is
used for initial screening of pathogens in the microbial universe for placement on the PCCL. As the
pathogens are screened through the 12 criteria, if a pathogen meets one criterion, the pathogen will
be excluded from moving on to the PCCL. All pathogens that pass through all screening criteria are
moved to the PCCL.
For the CCL 5, EPA re-evaluated the 12 criteria for applicability to microbes and reviewed certain
criteria in depth per recommendations received from previous CCL Science Advisory Boards.
For past CCLs, microorganisms that had outbreaks with no connection to contaminated distribution
system water as their cause were screened out. Thus, outbreaks occurring due to nosocomial
exposure or attributable to recreational water resulting from post-delivery contamination of drinking
water were not sufficient to place a microorganism on the PCCL unless the drinking water was shown
to be contaminated. A literature search was conducted for citations from 2009-2019 to look for
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October 2022
Agency Discussion on Microbial Screening Process/Criteria
Comment Excerpt from Commenter 77
In reviewing the CCL 5 process as described by the Agency, AWWA found:
1. The Science Advisory Board review of CCL 4 led EPA to modify Criterion 9 in its
screening of microbial contaminants to no longer exclude pathogens for which the only drinking
water-related infections were nosocomial epidemiology. [FN20: SAB. 2016. Review of the EPA's Draft
Fourth Contaminant Candidate List (CCL4).] This is a substantial and important change to the CCL
process as nosocomial infections occur under a unique combination of exposure scenarios and involve
individuals that are very susceptible to infection. Nosocomial infections often involve individuals or
exposure scenarios that require a completely sterile environment. This change was important to the
inclusion of Mycobacterium abscessus and Pseudomonas aeruginosa in CCL 5, but neither the Draft
CCL 5 Federal Register Notice nor the "Technical Support Document for the Draft Fifth Contaminant
Candidate List (CCL 5) - Microbial Contaminants" describe the weight-of-evidence approach used
when applying the revised Criterion 9. If EPA finalizes CCL 5 retaining the incorporation of this
modified criterion, it must more clearly describe its approach to implementing the revised criterion.
Individual Response: Please see Discussion on Microbial Screening Process/Criteria.
EPA addresses this comment in the document Technical Support Document for the Final Fifth
Contaminant Candidate List (CCL 5) - Microbial Contaminants.
Draft CCL 5-Microbes
Agency Discussion on Draft CCL 5-Microbes
Agency Topic Discussion:
As specified in Section 1412(b)(1) of the 1996 Safe Drinking Water Act (SDWA) Amendments, the CCL
must include contaminants that are not subject to any proposed or promulgated National Primary
Drinking Water Regulations.
The Microbial Disinfection By-product (MDBP) rulemaking and the Regulatory Determination process
are separate processes from the listing of a contaminant on the CCL and are both outside the scope of
the CCL process.
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Comments Received on Draft CCL 5-Microbes
Comment Excerpt from Commenter 89
We also urge inclusion in the MDBP rulemaking and a positive regulatory determination for key
priority microbes, including some of the agency's most highly ranked pathogens including Naegleria
fowleri, Legionella pneumophila, E. coli (0157), Pseudomonas aeruginosa, Helicobacter pylori,
Campylobacter jejuni, Mycobacterium abcessus, Shigella sonnei, Caliciviruses, and Mycobacterium
avium. These and other pathogens, including those on EPA's proposed CCL 5, can and should be
efficiently considered as part of the upcoming MDBP rulemaking. As additional information becomes
available, we may add to the list of chemicals and pathogens for which we recommend a positive
regulatory determination.
Overall, EPA should include in the CCL 5 all 66 individual chemicals and 12 microbes proposed if
regulatory action has not been initiated for them with an urgent threat to health finding or a positive
regulatory determination.
Individual Response: Please see Discussion on Draft CCL 5-Microbes and Other Drinking Water
Programs (RegDet; UCMR).
Comment Excerpt from Commenter 89
Finally, we believe that several of the pathogens that ranked high on EPA's assessment should also be
considered immediately for positive regulatory determinations and inclusion as appropriate in the
upcoming MDBP rulemaking, including for example Naegleria fowleri, Legionella pneumophila, E. coli
(0157), Pseudomonas aeruginosa, Helicobacter pylori, Campylobacter jejuni, Mycobacterium
abcessus, Shigella sonnei, Caliciviruses, and Mycobacterium avium.
Individual Response: Please see Discussion on Draft CCL 5-Microbes and Other Drinking Water
Programs (RegDet; UCMR).
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Legionella pneumophila
Agency Discussion on Legionella pneumophila
Agency Topic Discussion: Legionella pneumophila is a pathogenic bacterium that is commonly found
in moist environments including drinking water sources. Legionella bacteria can multiply in water
distribution systems and building plumbing under certain conditions, such as inadequate disinfectant
level, high water age, and warm water temperatures. These conditions usually occur in buildings with
large or complex water piping systems. However, these conditions can also occur under certain
circumstances in drinking water distribution systems.
Legionellosis is the name for two diseases, Pontiac Fever and Legionnaires' disease, Legionella
bacteria can cause. Pontiac Fever is a mild, flu-like illness and usually resolves on its own and
Legionnaires' Disease is a type of pneumonia (lung infection) that can have serious health implications
generally requires treatment.
Legionella pneumophila is proposed for CCL 5 because it has been identified in numerous Waterborne
disease outbreaks and is the most common cause of reported drinking water-associated outbreaks in
the U.S.
The Surface Water Treatment Rules (SWTR) (54 FR 27486, USEPA, 1989a) established a maximum
contaminant level goal (MCLG) of zero for Legionella. Since measuring disease-causing microbes in
drinking water was not considered to be feasible at the time of the development of the SWTR, EPA
established treatment technique for Legionella. However, Legionella is subject to limitations through
the treatment techniques under the SWTRs.
Because Legionella pneumophila is a known public health risk associated with distribution and
building water systems, Legionella pneumophila is listed on the CCL.
Furthermore, Legionella pneumophila was the most nominated contaminant for CCL 5, receiving 18
nominations.
Comments Received on Legionella pneumophila
Comment Excerpt from Commenter 62
To argue in reference to the already existing nominations, this commentary seeks to add further
support of 2 contaminants: a) Legionella pneumophila; and b) HAA6Br, known as brominated halo
acetic acids.
We maintain that these 2 contaminants have been overlooked over the years due to poor plumbing
or outdated rules, and their dangers have been caused to prove illness either in humans or laboratory
animals.
Individual Response: Please see Discussion on Legionella pneumophila and DBPs. EPA agrees with
listing Legionella pneumophila on the CCL 5.
Comment Excerpt from Commenter 62
A) Legionella pneumophila: a naturally occurring bacterium found in water, particularly in fresh bodies
of water. When inhaled by small droplets, it can cause serious lung disease (Legionnaires Disease),
particularly with the vulnerable. The bacterium can be present in old water pipes, outdated air
conditioners, and sewage systems and is very difficult to treat as the bacteria attaches itself to pre-
existing biofilms and is resilient to biocides (1)
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Comments Received on Legionella pneumophila
(l)Kim, B. R., Anderson, J. E., Mueller, S. A., Gaines, W. A., and Kendall, A. M. (2002). "Literature
review-efficacy of various disinfectants against Legionella in water systems." Water Res. 36, 4433-
4444. doi: 10.1016/S0043-1354(02)00188-4.
Individual Response: Please see Discussion on Legionella pneumophila and DBPs.
Comment Excerpt from Commenter 75
The following comments provide additional detail on contaminants listed on the Draft CCL 5 that are a
particular concern for state drinking water programs.]
Legionella
Legionella continues to present a microbial concern for states and is the most significant cause of
waterborne disease outbreaks. Although the key to preventing Legionnaires' disease is ensuring
building owners and managers maintain building water systems to reduce the risk of Legionella
growth and spread, water systems play a crucial role in delivering safe and high-quality water to these
buildings.
Part 141.3 of the National Primary Drinking Water Regulations, which is based on Section 300g-l (a)
of the Safe Drinking Water Act, specifies that buildings served by a public water system that meet
criteria that might otherwise make them a consecutive water system, are not regulated if they meet
four criteria, the first of which is that they do not treat the water. Treatment is not defined in this
exception which leaves it open to state interpretation, although EPA has issued guidance on the
definition of treatment (EPA WSG 8, 8A & H26). As awareness of Legionella continues to grow, some
buildings are installing devices or treatment to address microbial contaminants, including Legionella,
in their plumbing. States have taken various approaches to address building water systems, ranging
from regulating them as public water systems, contacting critical categories of water users (like health
care facilities) to request documentation about any treatment that might be installed to relying on
state or local building codes to govern these facilities rather than actively regulating them. The
biggest concern for states as they consider how to address building water systems is the state
resources needed to regulate these facilities. Also, assuring treatment effectiveness and optimization
coupled with a health care facility's CMS-required Water Management Plan are additional challenges
for all involved professionals. While many thousands of new public water systems could result from
aggressively identifying and regulating buildings water systems, potential adverse public health
consequences can occur by not regulating building water systems, including chemical overfeeds.
While it is primarily considered a premise plumbing problem, studies have also linked Legionella
pneumophila to detections and amplification in storage tanks, and the water sector should be looking
holistically at addressing this contaminant. ASDWA recommends that EPA develop a holistic research
strategy in coordination with the Centers for Disease Control and Prevention (CDC) for this
contaminant, including new or validated analytical methods, occurrence research and regulatory
strategies for reducing occurrence. This should include research on the removal of protozoa that
harbor Legionella and compare this to the CT (concentration of a disinfectant multiplied by the
contact time) and log filtration credit for Cryptosporidium and Giardia. Additional research is needed
on amoebae serving as a seeding vehicle for Legionella in the distribution system and premise
plumbing to ensure confidence that the existing treatment technique adequately addresses
Amoebae-Legionella interactions. Such a research plan should also include developing directions
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Comments Received on Legionella pneumophila
detailing when and where to test for Legionella pneumophila and remediation actions to take once it
is found. Jointly developed guidance from EPA and CDC in this area is needed and welcome.
Individual Response: Please see Discussion on Legionella pneumophila and DBPs. EPA agrees that
Legionella pneumophila is a microbial concern and mitigating Legionella in drinking water systems and
building water systems is a complex issue. EPA agrees additional research is needed for Legionella and
will consider the commenter's research recommendations.
Comment Excerpt from Commenter 77
[AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.]
CCL Development Process
There are aspects to the Draft CCL 5 that EPA should address in preparing the Final CCL 5 and in
preparation of future CCLs.
Coordination with Other SDWA Processes
The Draft CCL 5 includes many microbial pathogens and disinfection byproducts (M/DBPs). Some of
these contaminants, like Legionella pneumophila and brominated haloacetic acids, are currently the
focus of EPA's effort to consider potential revisions of M/DBP rules. [FN10: EPA, 2021. Potential
Revisions of Microbial and Disinfection Byproducts Rules. Accessed August 24, 2021.] EPA
presentations as part of the ongoing stakeholder process have raised the possibility of including a
wider range of pathogens and DBPs. [FN11: Ibid] The ongoing regulatory development process for
M/DBPs is occurring on a short, fixed schedule to comply with a legal settlement (i.e., the same
lawsuit that set a schedule for finalizing the CCL 5). [FN12: 2020. Waterkeeper Alliance, Inc. et al. v.
US. EPA and Andrew Wheeler. (19 Civ.899 (UL), U.S. District Court Southern District of New York).]
Despite the parallel timing of the Draft CCL 5 Federal notice with the M/DBP process, EPA has not
provided any information regarding how the inclusion of pathogens and DBPs on the CCL 5 will impact
the potential revisions, or vice versa. The Final CCL 5 Federal Register notice should address how
these two processes will interplay with respect to M/DBPs.
Individual Response: Please see Discussion on Legionella pneumophila, DBPs
and Other Drinking Water Programs.
Mycobacterium
Agency Discussion on Mycobacterium
Agency Topic Discussion:
Mycobacterium abscessus and Mycobacterium avium are listed on the CCL 5. Mycobacterium
abscessus and Mycobacterium avium are species of Mycobacterium that have adverse health risks
and that have been identified in recent waterborne disease outbreaks. Mycobacterium abscessus is a
bacterium that has never been on the CCL before. Mycobacterium avium has been listed on CCL 3 and
4.
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Comments Received on Mycobacterium
Comment Excerpt from Commenter 77
Inclusion of Mycobacterium avium and M. abscessus
AWWA supports the inclusion of Mycobacterium avium and M. abscessus on CCL 5. AWWA has
previously recommended the inclusion of M. avium for inclusion in the CCL [FN32: AWWA, 2009,
Comment submitted on Drinking Water Contaminant Candidate List 3 - Draft, EPA-HQ-OW-2007-
1189-0100.] [FN33: AWWA.2015. Comment submitted on Drinking Water Contaminant Candidate List
4 - Draft, EPA-HQ-OW-2012-0217-0059. ] M. avium and M. intracellular, which are very similar
genetically, are responsible for the greatest majority of recognized pulmonary nontuberculous
mycobacterial disease in the United States, but the number of cases of M. abscessus is growing
rapidly. [FN34: Kasperbauer, Shannon H. 2017. Nontuberculous Mycobacteria (NTM) Overview.
National Jewish Hospital. Accessed 9/2/2021 at https://www.nationaljewish.org/conditions/ntm-
nontuberculous-mycobacteria/ntm-nontuberculous-mycobacteria-overview] [FN35: Johansen, M.D.,
Herrmann, JL. & Kremer, L. Non-tuberculous mycobacteria and the rise of Mycobacterium abscessus.
Nat Rev Microbiol 18, 392-407 (2020). https://doi.org/10.1038/s41579-020-0331-l] CDC does not
identify drinking water as a key exposure for M. abscessus but case studies of nosocomial infections
have involved on-site uses of potable water. [FN36: CDC. Mycobacterium abscessus in Healthcare
Settings. Accessed 9/3/2021 at https://www.cdc.gov/hai/organisms/mycobacterium.html]
For simplicity, researchers and clinicians will refer to "non-tuberculosis Mycobacterium" (e.g., a group
of 190 non-tuberculosis Mycobacterium) (NTM). [FN37: Clinical Infectious Diseases, Volume 71, Issue
4, 15 August 2020, Pages el-e36, https://doi.org/10.1093/cid/ciaa24138] The NTM nomenclature
was initially a product of available analytical tools (i.e., phenotypic criteria based on colony
morphology and biochemical metabolism) and an international focus on addressing tuberculosis.
[FN38: Runyon EH: Typical mycobacteria: their classification. Am Rev Respir Dis. 1965;91:288-9.] Only
nine NTM are generally associated with disease. [FN39: Kasperbauer, Shannon H. 2017.
Nontuberculous Mycobacteria (NTM) Overview. National Jewish Hospital. Accessed 9/2/2021 at
https://www.nationaljewish.org/conditions/ntm-nontuberculous-mycobacteria/ntm-nontuberculous-
mycobacteria-overview40] [FN40: Note mycobacteria avium complex is defined as a group of 10
mycobacteria species.] At present, with our understanding of the Mycobacterium species that
represent a significant health threat, NTM is not an appropriate grouping to include in the CCL.
Individual Response: Please see Discussion on Mycobacterium. EPA agrees with listing speciated
Mycobacterium, Mycobacterium abscessus and Mycobacterium avium on the CCL 5.
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Contaminants Not on the Draft CCL 5 (Hepatitis A and Salmonella enterica)
Agency Discussion on Contaminants Not on the Draft CCL 5
Agency Topic Discussion:
Hepatitis A and Salmonella enterica are not listed for CCL 5. Although both contaminants were listed
on past CCLs, nominated for CCL 5, and still pose public health concerns, the outbreak data from
CDC's National Outbreak Reporting System indicate that the route of exposure is not waterborne for
the majority of infections.
Data reported to CDC's National Outbreak Reporting System suggest that there has been a decline in
the occurrence of Hepatitis A outbreaks in public drinking water systems. These findings support the
proposal to exclude hepatitis A from CCL 5. In addition, no waterborne outbreaks for Hepatitis A were
reported during 2009-2017. However, EPA acknowledges that Hepatitis A reported cases have
increased and is a public health issue, however the etiology is unknown.
Although Salmonella enterica was listed for CCL 3 and CCL 4, nominated for CCL 5, and continues to
have serious health risks, data reported to CDC's National Outbreak Reporting System suggest the
route of exposure for outbreaks documented between 2009-2017 were not waterborne. Instead, the
numerous Salmonella outbreaks within the timeframe examined for CCL are reported as foodborne
exposure.
Therefore, Hepatitis A and Salmonella enterica are not listed on CCL 5.
Comments Received on Contaminants Not on the Draft CCL 5
Comment Excerpt from Commenter 98
The presence of microbes like the Hep A virus and a strand of salmonella on the list is crucial to the
future protection of our water and health in accordance with the SDWA. I acknowledge the possible
costs that could come from regulating some of these newer chemicals, but the costs are outweighed
by the benefits. The continued battle to keep our drinking water safe in today's age of newfound
chemical usage should always be a priority, and the CCL 5 is certainly a step in the right direction.
Individual Response: Please see Discussion on Contaminants Not on the Draft CCL 5. Hepatitis A and
Salmonella enterica did not have high enough composite scores for occurrence (waterborne disease
outbreaks and occurrence supported by literature) and health effects to place them in the 12 highest
scoring microbes, placing them on the CCL 5.
Perchlorate
Agency Discussion on Perchlorate
Agency Topic Discussion:
EPA received multiple comments regarding the July 21, 2020, decision to not regulate perchlorate in
drinking water; this decision withdrew a previous positive regulatory determination for perchlorate
made on February 11, 2011, under the second cycle of the Regulatory Determination process. While
CCL and Regulatory Determination are interrelated, they are separate steps to the drinking water
regulatory process authorized under SDWA.
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Agency Discussion on Perchlorate
Comment Excerpt from Commenter 87
Finally, we strongly urge you to reconsider, and to ultimately reverse, the arbitrary, capricious, and
unlawful decision by the previous administration not to regulate Perchlorate under the SDWA. As you
are undoubtedly aware, EPA correctly determined a decade ago that Perchlorate meets the statutory
criteria set forth in SDWA section 1412(b)(1)(A), and the agency thus published a proposed drinking
water standard to regulate this extremely dangerous contaminant. As EPA acknowledged when it
decided last year to reverse course and not finalize a drinking water standard for Perchlorate, EPA had
never before reversed a SDWA regulatory determination. The agency had no legitimate factual or
legal basis to do so here. Not only did the decision defy a court order and the law, it ignored the
science that—according to the American Academy of Pediatrics and many others—dictates a strong
perchlorate standard to protect vulnerable kids. We urge you to reverse the decision of the previous
Administration and to re-propose the Perchlorate rule, with a strict standard along the lines of those
already adopted in California and Massachusetts.
Respectfully submitted,
Daniel E. Estrin
General Counsel and Advocacy Director
Individual Response: Please see Discussion on Perchlorate.
Comment Excerpt from Commenter 97
EPA must also reverse its 2020 decision not to regulate perchlorate contaminants levels in drinking
water under the SDWA.
Individual Response: Please see Discussion on Perchlorate.
Comment Excerpt from Commenter 101
EPA must also reverse its 2020 decision not to regulate perchlorate contaminants levels in drinking
water under the SDWA. Perchlorate is an extremely dangerous industrial chemical used for things like
rocket fuel and should not be in our tap water. EPA already determined, nearly 10 years ago, that
perchlorate meets the SDWA requirements for regulation and already published a proposed standard.
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Comments Received on Perchlorate
It is important for the health of our children that EPA adopts safe limits for perchlorate in drinking
water and there is no good reason for EPA not to take this action.
Individual Response: Please see Discussion on Perchlorate.
Comment Excerpt from Commenter 103
EPA must also reverse its 2020 decision not to regulate perchlorate contaminants levels in drinking
water under the SDWA. Perchlorate is an extremely dangerous industrial chemical used for things like
rocket fuel and should not be in our tap water. EPA already determined, nearly 10 years ago, that
perchlorate meets the SDWA requirements for regulation and already published a proposed standard.
It is important for the health of our children that EPA adopts safe limits for perchlorate in drinking
water and there is no good reason for EPA not to take this action.
Individual Response: Please see Discussion on Perchlorate.
Endocrine Disruptor Chemicals (EDCs) and Pharmaceuticals and Personal Care
Products (PPCPs)
Agency Discussion on EDCs and PPCPs
Agency Topic Discussion:
Early in the CCL development process, EPA evaluated 134 potential primary data sources that were
used for building the CCL 5 Universe. As directed by SDWA, EPA considered health effects and
occurrence data sources to identify unregulated contaminants that present the greatest public health
concern related to exposures from drinking water. Table 1, Table 2, Appendix A, and Appendix N of
the Final CCL 5 Chemical Technical Support Document provide additional details on the data sources
used for CCL 5 (USEPA, 2022a). Many of the data sources included health effects data on endocrine
disruption, such as the Endocrine Disruption Screening Program (EDSP) data incorporated from the
CompTox Dashboard. CCL 5 data sources also included many contaminants which are considered to
be pharmaceuticals and personal care products (PPCPs). Therefore, endocrine disruption, as a health
effect, and PPCPs were included in the CCL 5 process with the other chemicals in the CCL 5 Universe.
Comments Received on EDCs and PPCPs
Comment Excerpt from Commenter 53
To Whom It May Concern:
I support the regulation of the "66 individual chemicals, 12 microbes, and three chemical groups - per-
and polyfluoroalkyl substances (PFAS), cyanotoxins, and disinfection byproducts (DBPs)" (EPA, 2021,
para. 3) - that have been included in the Contaminant Candidate List (CCL) 5 Proposed Rule. However,
I urge the EPA to add Endocrine Disruptors (EDCs) found in pharmaceuticals and personal care
products (PPCPs) to the list of regulated chemicals to prevent the prevalence of drinking water-
induced reproductive health impairments.
EDCs include "disinfection byproducts, fluorinated substances, bisphenols, phthalates, pesticides, and
natural and synthetic estrogens" (Gonsioroski et al., 2020, p. 1). The National Institute for
Environmental Health Sciences (NIEHS) states that these harmful chemicals can be found in plastic
bottles, food containers, detergents, toys, cosmetics, and pesticides (NIEHS, 2019). Research shows
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Comments Received on EDCs and PPCPs
that EDCs have been proven to undermine the safety of drinking water by affecting development,
fertility, and reproductive function. For example, "exposure to water disinfection byproducts in
drinking water can cause cardiac anomalies in developing rat and porcine embryos" (Gonsioroski et
al., 2020, p. 2). Additionally, pesticide exposure "is associated with low sperm count and adverse
pregnancy outcomes in non-human animals and humans" (Gonsioroski et al., 2020, p. 2). The severity
of the reproductive and fertility effects of EDCs can clearly be demonstrated by existing research.
Thus, it is essential that public health be prioritized through the addition of EDCs on the CCL 5 draft.
It is important to note that PFAS, which can be found in nonstick pans, household products, cleaning
products, fabrics, polishes, and waxes (Gonsioroski et al., 2020), was added to the EPA's CCL 5 draft
due to its determination as a harmful chemical category that has significant effects on the human
body. EDCs should be considered for the CCL 5 draft, as they introduce the same level of severity and
harm to the human body. Similarly, EDCs are a group of toxic chemicals that affect fertility,
reproductive function, and human development and must be added to the EPA's CCL 5 draft to
uphold public safety and prioritize wellness in the United States.
References:
EPA. (2021). EPA identifies drinking water contaminants for potential regulation.
https://www.epa.gov/newsreleases/epa-identifies-drinking-water-contaminants-potential-regulation
Gonsioroski, A., Mourikes, V. E., & Flaws, J. A. (2020). Endocrine Disruptors in Water and Their
Effects on the Reproductive System. International journal of molecular sciences, 21(6), 1929.
https://doi.org/10.3390/iims21Q61929
NIEHS. (2019, December 10). Endocrine Disruptors.
https://www.niehs.nih.gov/research/supported/exposure/endocrine/index.cfm
Individual Response: Please see Discussion on EDCs and PPCPs.
Suggestions to Improve the Process for Future CCLs
Agency Discussion on Suggestions to Improve the Process for Future CCLs
Agency Topic Discussion:
In each cycle of the CCL, EPA attempts to improve the efficiency and transparency of the CCL
development process in response to comments from the Science Advisory Board and the public. In
developing the CCL 5, EPA has made many improvements to the CCL process to better identify,
screen, and classify potential drinking water contaminants. This included using new approaches to
rapidly screen a significantly larger universe of contaminants for the CCL 5, prioritizing data most
relevant to drinking water exposure, and identifying contaminants with the potential for the greatest
public health concern, with a better consideration for sensitive populations, including children. These
improvements resulted in a CCL 5 that can better support prioritization of chemicals for regulatory
and research efforts. For more information on improvements made to the CCL 5 process, please see
the Final CCL 5 Chemical Technical Support Document (USEPA, 2022a) and Final CCL 5 Microbial
Technical Support Document (USEPA, 2022c).
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Agency Discussion on Suggestions to Improve the Process for Future CCLs
In EPA's Drinking Water Contaminant Candidate List 5-Draft notice, published in the Federal Register
on July 19, 2021, the agency requested comment on improvements implemented in the CCL 5 process
for consideration in developing future CCLs. EPA received many public comments commending
improvements made in the CCL 5 as well as many public comments providing recommendations for
EPA to improve specific aspects of the CCL process and how it is presented. EPA has categorized and
addressed these comments in other sections of this document where appropriate, such as the
discussions on General Comments. Chemical Data/Data Sources. Chemical Technical Support
Document, and Microbial Technical Support Document. EPA also received a comment which provided
more general recommendations for EPA to improve the process for future CCLs and provide greater
clarity around the CCL 5. This comment is included and addressed here in this section of the
document. EPA will take all these comments into consideration when developing future CCLs.
Comments Received on Suggestions to Improve the Process for Future CCLs
Comment Excerpt from Commenter 77
[AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.]
Communicate Priorities Within CCL.
The development process for the CCL is complex and the CCL itself is the product of an extensive
review of available data. EPA should consider presenting the Final CCL 5, and future CCLs, as an
organized list that illustrates relative levels of potential risk and the gaps in information needed to
craft risk management decisions. Such an approach would accomplish the following benefits:
1. Help EPA prioritize research needs internally
2. Inform stakeholders on research goals (both short-term and long-term).
3. Clearly indicate to consumers what priorities the Agency has identified and the potential level of
concern that they present
Individual Response: Please see Discussion on Suggestions to Improve the Process for Future CCLs.
Other Drinking Water Programs, and Other EPA Programs. The commenter noted the complexity of
the CCL development process and recommended that the Final CCL 5 and future CCLs be presented as
"an organized list that illustrates relative levels of potential risk and the gaps in information needed to
craft risk management decisions." The CCL is a list of contaminants, not currently subject to any
proposed or promulgated NPDWR that are known or anticipated to occur in public water systems and
may require regulation under SDWA. For relative levels of potential risk and information needs for
different CCL 5 contaminants, EPA recommends the commenter view the Contaminant Information
Sheets (CISs) which display health effects, occurrence, and other data on CCL 5 contaminants (see
Final CCL 5 CIS Technical Support Document for chemicals (USEPA, 2022b) and Appendix F of Final CCL
5 Microbial Technical Support Document for microbes (USEPA, 2022c)). In addition, EPA has provided
a table summarizing the data availability for CCL 5 chemicals (please see Chapter 5 of the Final CCL 5
Chemical Technical Support Document (USEPA, 2022a)).
Comment Excerpt from Commenter 77
[AWWA offers the following recommendations for EPA to consider as the CCL 5 is finalized and in the
development of future CCLs.]
External Peer-Review
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Comments Received on Suggestions to Improve the Process for Future CCLs
EPA engaged in an extensive process to develop CCL 5, particularly in comparison to CCLs 1, 2, and 4.
However, EPA prepared the Draft CCL 5 Federal Register notice without seeking external expert
review as was recommended by NDWAC and has been past practice (e.g., CCLs 1 and 3). AWWA
appreciates that the draft CCL 5 will be reviewed by the Science Advisory Board but recommends that
future CCLs be reviewed by an external expert panel in advance of the proposal. As is demonstrated
by the two technical support documents that underpin the Draft CCL 5, it is challenging to develop the
CCL process algorithm without resolving a lengthy series of individual questions of process and data
quality. Without an external review, it is difficult to evaluate one's own work as to whether the
completely assembled product works as it should. The technical support documents do not describe
any internal process control measures, making the role of an independent third-party review even
more important. The use of multiple chemical evaluator teams only serves as an internal check on
one step in preparation of the CCL.
Individual Response: Please see Discussion on Suggestions to Improve the Process for Future CCLs
and General Comments. In developing the updated process used to select drinking water
contaminants for the CCL 5, EPA considered previous recommendations put forth by external groups,
including those contained in the National Drinking Water Advisory Council Report on the CCL
Classification Process (NDWAC, 2004), previous SAB reviews, and external expert reviews conducted
for CCL 3. As the commenter indicates, the NDWAC report recommended critical review during key
milestones of the CCL process: "Expert judgment, possibly including external expert consultation, will
be important throughout the process, but particularly at key points, such as: reviewing the screening
criteria and process from the Universe to the PCCL; assessing the training data set; and classification
algorithm performance during development of the PCCL to CCL classification step." CCL 3 conducted
extensive external reviews at each step of the process, including the review of the classification
algorithms, yet internal expert judgement was critical for reviewing the output from the classification
algorithms and making final listing decisions. While the development of the CCL 5 relied heavily on
the internal expert judgement, EPA will consider the need for conducting external expert reviews for
future CCLs.
EPA disagrees with the commenter's assertion that the technical support documentation does not
describe any internal process control measures; both Chapter 6 "Data Management and Quality
Assurance" and Appendix N "Data Management for CCL 5" of the Final CCL 5 Chemical Technical
Support Document demonstrate adherence to an internal quality control system (USEPA, 2022a). In
addition, EPA worked diligently throughout the development of CCL 5 to ensure that the project
adhered to sound methodology for the collection and management of the health effects and
occurrence data for each contaminant.
Comment Excerpt from Commenter 77
It is important to note that EPA did identify some issues that warranted more detailed explanation of
its methodology and its impact. An example is the treatment of cancelled pesticides, where there is
an obvious concern that, while older data may indicate occurrence and there would be available
health information, drinking water is much less likely to represent an ongoing source of exposure for
a cancelled pesticide. EPA's summary illustrates how available data is and can be used to identify
those cancelled pesticides that might pose a continuing risk. A more routine practice of reflecting on
the impact of methodological decisions would help the public and facilitate improvement of the CCL
process over time.
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Comments Received on Suggestions to Improve the Process for Future CCLs
It is also not clear what effect significant methodological changes over past practice have had on the
composition of CCL 5. The public would benefit from a fuller explanation of the CCL 5 process and
insight into the influential decisions made in the construction of the CCL 5.
Individual Response: Please see Discussion on Suggestions to Improve the Process for Future CCLs.
Pesticides, and Chemical Technical Support Documents. EPA describes the impact of methodological
changes made in the CCL 5 process throughout the Final CCL 5 Technical Support Document (USEPA,
2022a). The commenter provided one such example related to the treatment of cancelled pesticides.
However, the commenter states that "A more routine practice of reflecting on the impact of
methodological decisions would help the public and facilitate improvement of the CCL process over
time." EPA will consider conducting analyses to assess the potential impact of changes made to the
CCL 5 process, identifying areas for improvement, and incorporating them into future CCLs. EPA has
worked on making the CCL process more transparent through the Final CCL 5 support documents and
will also work to make the process more transparent in documentation for future CCLs.
Comments Outside the Scope of CCL
Comment Excerpt from Commenter 51
There should be a US Department of Water with cabinet positions.
And water consumption should be as follows: if it doesn't belong in the body, it doesn't belong in our
water. Use a white list of chemicals allowed in our drinking water. A black list of what chemicals aren't
allowed only let's the water be healthy enough to current standards, which will prove unhealthy in a
few years as it always does
Individual response: Please see Discussion on General Comments. The establishment of a U.S.
Department of Water with cabinet positions is outside the scope of the CCL.
Comment Excerpt from Commenter 57
1) Is the rule outcome to require neutralization of the final list of contaminants at factories that
generate them, and at water treatment plants prior to household use?
2) Where were testing samples drawn?
3) Would there be label warnings on bottled waters on possible traces of the finalized contaminants?
Individual Response: Please see Discussion on General Comments. Other Drinking Water Programs.
and Other EPA Programs. The U.S. Food and Drug Administration sets standards for bottled water. For
more information on bottled water, please see EPA's Water Health Series document on Bottled Water
Basics.
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Comments Received on Outside the Scope
Comment Excerpt from Commenter 90
Dear Administrator Regan,
Please ensure that the execrable situation that afflicted Flint, Michigan, never again affects anyone in
this country.
Individual Response: EPA continues to take steps to address lead in the nation's drinking water. For
more information on EPA's efforts to better protect the public from exposures to lead in drinking
water, please see https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-
lead-drinking-water
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References
I. Center for Disease Control (CDC). 2019. Fourth National Report on Human Exposure to
Environmental Chemicals Updated Tables, January 2019, Volume One. Available at
https://stacks.cdc.gov/view/cdc/75822/cdc 75822 DSl.pdf
II. Domingo, J.L., J.L. Llobet, J.M. Tomas et al. 1985. Short-term toxicity studies of vanadium in rats.
J. Appl. Toxicol. 5:418-421.
III. Institute of Medicine (IOM). 2001. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic,
Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium
and Zinc. The National Academy Press. Washington DC. pp 420-444, 552-543.
IV. Institute of Medicine (IOM). 2006. Dietary Reference Intakes. The Essential Guide to Nutrient
Requirements. The National Academy Press, Washington DC. ppl89-195, 356-362, 415-422.
V. 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. Available at https://www.epa.gov/sites/default/files/2014-
07/documents/report ccl ndwac 07-06-04.pdf
VI. National Toxicology Program (NTP). 2021. NTP Technical Report on the Toxicology and
Carcinogenesis Studies of Sodium Tungstate Dihydrate (CASRN 10213-10-2) in Sprague Dawley
(Hsd:Sprague Dawley® SD®) Rats and B6C3F1/N Mice (Drinking Water Studies), November, 2021.
Available at https://ntp.niehs.nih.gov/ntp/htdocs/lt rpts/tr599 508.pdf
VII. Organization for Economic Co-operation and Development, "Reconciling terminology of the
universe of per- and polyfluoroalkyl substances: recommendations and practical guidance,"
(OECD Series on Risk Management No. 61, 2021);
https://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=ENV/CBC/MONO(2
021)25&docLanguage=En.
VIII. USEPA. 2009a. METHOD 537. DETERMINATION OF SELECTED PERFLUORINATED ALKYL
ACIDS IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID
CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS). EPA/600/R-08/092.
September 2009. Available at
https://www.regulations.gov/docket/EPA-HQ-OW-2009-
0090/document?documentTypes=Supporting%20%26%20Related%20Material
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(CCL 3). U.S. Environmental Protection Agency, Office of the Administrator, Science Advisory
Board. EPA-SAB-09-011. January 2009. Available at
https://www.epa.gov/sites/default/files/2014-05/documents/sab-ccl-3-advisory.pdf
X. USEPA. 2015. Recommendations for Public Water Systems to Manage Cyanotoxins in Drinking
Water. EPA Document No. 815-R-15-010, Washington, DC; 2015. Available at:
http://www2.epa.gov/nutrient-policy-data/ guidelines-and-recommendations
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XI. USEPA. 2017. National Primary Drinking Water Regulations; Announcement of the Results of
EPA's Review of Existing Drinking Water Standards and Request for Public Comment and/or
Information on Related Issues. 82 FR 3518. January 2017.
XII. USEPA. 2018. Request for Nominations of Drinking Water Contaminants for the Fifth
Contaminant Candidate List. 83 FR 50364. October 2018.
XIII. USEPA. 2019. METHOD 533: DETERMINATION OF PER- AND POLYFLUOROALKYL SUBSTANCES IN
DRINKING WATER BY ISOTOPE DILUTION ANION EXCHANGE SOLID PHASE EXTRACTION AND
LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY. EPA Document No. 815-B-19-020.
EPA contract EP-C-17-014. November 2019. Available at
https://www.epa.gov/sites/default/files/2019-12/documents/method-533-815bl9020.pdf
XIV. USEPA. 2020. METHOD 537.1 DETERMINATION OF SELECTED PER- AND
POLYFLUORINATED ALKYL SUBSTANCES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND
LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS). EPA/600/R-20/006.
March 2020. Available at
https://www.regulations.gov/document/EPA-HQ-OW-2020-0530-00Q2
XV. USEPA. 2021a. National PFAS Testing Strategy: Identification of Candidate Per- and
Polyfluoroalkyl Substances (PFAS) for Testing. October 2021. Available at
https://www.epa.gov/svstem/files/documents/2021-10/pfas-natl-test-strategy.pdf
XVI. USEPA. 2021b. PFAS Strategic Roadmap: EPA's Commitments to Action 2021—2024. Available at
https://www.epa.gov/system/files/documents/2021-10/pfas-roadmap final-508.pdf
XVII. USEPA. 2021c. Revisions to the Unregulated Contaminant Monitoring Rule for Public Water
Systems; Public Meeting. 86 FR 13846. March 2021. Available at
https://www.regulations.gov/document/EPA-HQ-OW-2020-0530-0Q01
XVIII. USEPA. 2022a. Technical Support Document for the Final Fifth Contaminant Candidate List (CCL
5)—Chemical Contaminants. EPA 815-R-22-002, October 2022.
XIX. USEPA. 2022b. Technical Support Document for the Final Fifth Contaminant Candidate
List (CCL 5)—Contaminant Information Sheets. EPA 815-R-22-003, October 2022.
XX. USEPA. 2022c. Technical Support Document for the Final Fifth Contaminant Candidate List (CCL
5)—Microbial Contaminants. EPA 815-R-22-004, October 2022.
XXI. USEPA. 2022d. SAB Advisory on EPA's Draft Fifth Drinking Water Contaminant Candidate List
(CCL 5). U.S. Environmental Protection Agency, Office of the Administrator, Science Advisory
Board. EPA-SAB-22-007. August 2022. Available at
https://sab.epa.gov/ords/sab/f?p=114:18:17492342385800:::RP.18:P18 ID:2600#report
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XXII. World Health Organization (WHO)- Water, sanitation, hygiene, and waste management for
SARS-CoV-2, the virus that causes COVID-19. Interim guidance. COVID-19: Infection prevention
and control https://www.who.int/publications/i/item/WHO-2019-nCoV-IPC-WASH-2020.4, July
2020.
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