&EPA
Screening Document
United States .^ -rkx^x^T
Environmental Protection fOf the Draft PCCL 4
Agency
Nominated
Contaminants
-------
Office of Water (4607M)
EPA815-R-15-002
January 2015
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
Contents
1.0 Introduction 1
2.0 Summary of the CCL 3 Chemicals Screening Process 3
2.1 Health Effects Data Elements 4
2.2 Occurrence Data Elements 6
2.3 Selection of the PCCL 7
3.0 Screening the Nominated Chemicals from the CCL 4 Universe to the PCCL 8
4.0 Summary of the CCL 3 Microbes Screening Process and Screening of the Nominated
Microbes from the CCL 4 Universe to the PCCL 4 8
5.0 References 10
6.0 Appendices Al
Appendix 1. Screening data for the Nominated Chemicals in the CCL 4 Universe Al
Page i of vi
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
Page ii of vi
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
Exhibits
Exhibit 1: Partition for Screening the Universe 4
Exhibit 2: Potency Measures for Universe Data Element Partitioned Based on Toxicity
(mg/kg/day ormg/kg) 5
Exhibit 3: Partitioning of Cancer Data Based on TD50 Values and Weight of Evidence 6
Exhibit 4: Criteria for a Chemical to Pass to the PCCL 7
Page ill of vi
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
Page iv of vi
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
Acronyms and Abbreviations
< Less than
< Less than or equal to
> Greater than
> Greater than or equal to
|i Microgram, one
|ig/L Micrograms per liter
ADI Acceptable Daily Intake
AWWARF American Water Works Association Research Foundation
CASRN Chemical Abstract Services 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
CE Clear evidence of carcinogenicity
CUS/IUR Chemical Update System/Inventory Update Rule
DBF-CAN EPA Water Disinfection By-Products with Carcinogenicity Estimates
DSSTOX Distributed Structure-Searchable Toxicity Database Network
E Equivocal
EE Equivocal evidence of carcinogenicity
EPA United States Environmental Protection Agency
EPA HA EPA Health Advisory
FR Federal Register
g Gram
H High probability of causing cancer
HM High moderate probability of causing cancer
IARC International Agency for Research on Cancer
ITER International Toxicity Estimates for Risk
JECFA Joint FAO/WHO Expert Committee on Food Additives
kg Kilogram
L Liter
LDso Lethal dose 50; an estimate of a single dose that is expected to cause the death
of 50 percent of the exposed animals; it is derived from experimental data.
M Moderate probability of causing cancer
LM Low moderate probability of causing cancer
LOAEL Lowest Observed Adverse Effect Level
MCL Maximum Contaminant Level
Page v of vi
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
MCLG
mg/kg
mg/kg/day
mg/L
MRDD
N
NAWQA
NE
MRS
NOAEL
NCI
NCFAP
NDWAC
NRC
NREC
NTP
OPP
P
PFOA
PWS
QSAR
RfD
RAIS
RTECS
SDWA
SE
TDso
TRI
UCM Round 1
US
WHO
yr
Maximum Contaminant Level Goal
Milligrams per kilogram body weight
Milligrams per kilogram body weight per day
Milligrams per liter
Maximum Recommended Daily Dose
Negative
National Water Quality Assessment
No evidence of carcinogenicity
National Inorganics and Radionuclides Survey
No Observed Adverse Effect Level
National Cancer Institute
National Center for Food and Agricultural Policy
National Drinking Water Advisory Council
National Academy of Science's National Research Council
National Reconnaissance of Emerging Contaminants
National Toxicology Program
Office of Pesticide Programs
Positive
Perfluorooctanoic acid
Public water system
Quantitative Structure Activity Relationship
Reference dose
Risk Assessment Information System
Registry of Toxic Effects of Chemical Substances
Safe Drinking Water Act
Some evidence of carcinogenicity
Tumorigenic dose 50; The dose-rate which if administered chronically for the
standard life-span of the species will have a 50% probability of causing
tumors at some point during that period.
Toxics Release Inventory
Unregulated Contaminant Monitoring Round 1
United States of America
World Health Organization
Year
Page vi of vi
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
1.0 Introduction
Section 1412(b)(l) of the Safe Drinking Water Act (SOWA), as amended in 1996, requires EPA
to publish the Contaminant Candidate List (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 the agency 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, 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 published the third CCL (CCL 3), which listed 116 contaminants on October 8, 2009 (74
FR 51850 (USEPA, 2009a)). In developing the CCL 3, EPA implemented a multi-step process to
select contaminants for the final CCL 3, which included the following key steps:
(1) The identification of a broad universe of potential drinking water contaminants (CCL 3
Universe);
(2) Screening the CCL 3 Universe to a Preliminary CCL (PCCL) using screening criteria
based on the potential to occur in PWSs and the potential for public health concern;
(3) Evaluation of the PCCL contaminants based on a more detailed review of the occurrence
and health effects data using a scoring and classification system to identify a final list of
116 CCL 3 contaminants; and
(4) Incorporating public input and expert review in the CCL 3 process.
Steps 1, 2 and 3 in the process are described in detail in the CCL 3 support documents:
• Final CCL 3 Chemicals: Identifying the Universe (USEPA, 2009b);
• Final CCL 3 Chemicals: Screening to a PCCL (USEPA, 2009c);
• Final Contaminant Candidate List 3 Chemicals: Classification of the PCCL to the CCL
(USEPA, 2009d);
• Final CCL 3 Microbes: Identifying the Universe (USEPA, 2009e);
• Final CCL 3 Microbes: Screening to the PCCL (USEPA, 2009f); and
• Final CCL 3 Microbes: PCCL to CCL Process (USEPA, 2009g).
These documents can be found on the EPA web site at: http://www2.epa.gov/ccl/contaminant-
candidate-list-3-ccl-3 or at http://www.regulations.gov (docket ID: EPA-HQ-OW-2007-1189).
After a Final CCL is published, SDWA section 1412(b)(l)(B)(ii) as amended in 1996, requires
EPA at five year intervals to make determinations of whether to regulate or not to regulate no
fewer than five contaminants from the CCL in a process called regulatory determinations. This is
Page 1 of 11
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
a separate process from the listing of contaminants on the CCL. The 1996 SDWA Amendments
specify three criteria to determine whether a contaminant may require regulation:
• the contaminant may have an adverse effect on the health of persons;
• the contaminant is known to occur or there is a substantial likelihood that the contaminant
will occur in PWSs 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 PWSs.
If EPA determines that these three statutory criteria are met and makes a final determination to
regulate a contaminant, the agency has 24 months to publish a proposed Maximum Contaminant
Level Goal1 (MCLG) and NPDWR2. After the proposal, the agency has 18 months to publish
and promulgate a final MCLG and NPDWR (SDWA section 1412(b)(l)(E))3.
On February 11, 2011, as a separate action, the agency issued a positive regulatory determination
for perchlorate, a chemical listed in CCL 1, CCL 2 and CCL 3 (76 FR 7762 (USEPA, 2011)).
Recently, EPA has published preliminary regulatory determinations for five unregulated
contaminants on the CCL 3 (79 FR 62716 (USEPA, 2014)). The five contaminants include:
dimethoate; 1,3-dinitrobenzene; strontium; terbufos and terbufos sulfone. The agency is making
preliminary determinations to regulate one contaminant (strontium) and to not regulate four
contaminants (dimethoate; 1,3-dinitrobenzene; terbufos; and terbufos sulfone). Therefore, the
agency is removing perchlorate and these five contaminants from the Draft Fourth CCL (CCL 4),
pending the result of the final regulatory determinations for CCL 3.
EPA conducted an abbreviated evaluation and selection process for the CCL 4. This abbreviated
CCL 4 process includes a three pronged approach: (1) carrying forward CCL 3 contaminants
(minus those with regulatory determinations), (2) seeking and evaluating nominations from the
public for additional contaminants to consider and (3) evaluating any new data for those
contaminants with previous negative regulatory determinations from CCL 1 or CCL 2 for
potential inclusion on the CCL 4.
As part of the process to develop the CCL 4, EPA published a Federal Register notice (77 FR
27057 (USEPA, 2012)) requesting that the public submit nominations for chemical and
microbial contaminants to be considered for inclusion in the CCL 4. EPA also requested
supporting information that has been made available since the development of the CCL 3, or
existing information that was not considered in the development of the CCL 3, which shows that
the nominated contaminant may have an adverse health effect on people, and occurs or is likely
1 The MCLG is the "maximum level of a contaminant in drinking water at which no known or anticipated adverse
effect on the health of persons would occur, and which allows an adequate margin of safety. Maximum contaminant
level goals are non-enforceable health goals." (40 C.F.R. 141.2; 42 U.S.C. 300g-l)
2 An NPDWR is a legally enforceable standard that applies to public water systems. An NPDWR sets a legal limit
(called a maximum contaminant level or MCL) or specifies a certain treatment technique (TT) for public water
systems for a specific contaminant or group of contaminants. The MCL is the highest level of a contaminant that is
allowed in drinking water and is set as close to the MCLG as feasible using the best available treatment technology
and analytical methods and taking cost into consideration.
3 The statute authorizes a nine month extension of this promulgation date.
Page 2 of 11
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
to occur in public water systems. EPA reviewed the nominations and supporting information
provided by nominators to determine if any new data were provided that had not been previously
evaluated for CCL 3. The agency also collected additional data for the nominated contaminants,
when it was available, from both CCL 3 data sources that had been updated and from new data
sources that were not available at the time of CCL 3. A complete list of references provided by
nominators can be found in the support document Summary of Nominations for the Fourth CCL
(USEPA, 2015a). A more detailed description of the CCL data sources collected by EPA may be
found in the support document Data Sources for the CCL 4 (USEPA, 2015b). EPA evaluated the
nominated contaminants utilizing the best available health effects and occurrence data and the
same process for screening and scoring contaminants that was used for CCL 3.
This document focuses on describing the second step in the CCL 4 process, in which EPA
applied screening criteria to the nominated contaminants in the CCL 4 Universe to identify a
Preliminary CCL (PCCL) based on a contaminant's potential to occur in public water systems
and the potential for public health concern. Appendix 1 shows the health effects and occurrence
data used to screen the nominated chemicals in the CCL 4 Universe to the PCCL 4.
2.0 Summary of the CCL 3 Chemicals Screening Process
The agency evaluated the nominated contaminants for CCL 4 utilizing the best available health
effects and occurrence data and the same process for screening and scoring contaminants that
was used for CCL 3. This section summarizes the process developed under CCL 3 to screen
chemicals from the Universe to the PCCL. A more detailed description of the screening process
can be found in the CCL 3 support document: Final CCL 3 Chemicals: Screening to a PCCL
(USEPA, 2009c). EPA developed criteria to screen chemicals from the CCL 3 Universe to the
PCCL 3. These screening criteria utilized available data (e.g., occurrence and health) to examine
a chemical's health effects relative to its occurrence.
The health effects information used included quantitative, descriptive or categorical information.
Within the aforementioned categories, there were various types of reported health related values
(e.g., RfD, LOAEL, NOAEL, LD50 or cancer classifications) from several data sources. A list
and detailed description of the data sources used in CCL 3 can be found in Final CCL 3
Chemicals: Identifying the Universe (USEPA, 2009b).
The occurrence information also included many types of available data representative of a
chemical's potential to occur in water. Occurrence data ranged from concentrations in finished
drinking water from PWSs, to concentrations of a chemical in ambient water, to environmental
release and production data. The basic framework EPA used in screening is shown in Exhibit 1.
EPA categorized the CCL Chemical Universe contaminants by their toxicity along the vertical
axis and by their occurrence on the horizontal axis. This allows for separation of chemicals into
those that move to the PCCL based on their toxicity and occurrence properties (e.g., upper right
in Exhibit 1) and those that are not further evaluated and remain in the CCL Chemical Universe
(e.g., lower left in Exhibit 1). EPA used a set of test chemicals to develop the screening criteria.
This set of chemicals included regulated and unregulated chemicals that provided comprehensive
information on health effects and occurrence in finished and/or ambient water as well as
Page 3 of 11
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
environmental release and production volume. EPA then used these criteria to select chemicals
for the PCCL for further consideration.
Exhibit 1: Partition for Screening the Universe
Health Effects
Occurrence
Low to High Occurrence
Increasing
Toxicity
Do not pass to PCCL
Lass to the PCCL
2.1 Health Effects Data Elements
EPA evaluated the toxicity information and health effects data compiled from the data sources in
the Universe and these data varied greatly. Some of these data are quantitative (e.g.,
RfD, LOAEL, NOAEL, LDso) and some are descriptive (e.g., cancer classifications or
predictions). EPA designed the screening process to accommodate both types of health effects
data.
EPA divided the chemicals in the Universe into five toxicity categories for screening based upon
the distribution of the toxicity value for each type of quantitative data element and/or the
qualitative information on cancer weight-of-evidence. The five toxicity categories are designated
1 through 5, with Toxicity Category 1 containing chemicals in the most toxic grouping and
Toxicity Category 5 the least toxic grouping. Based upon the distribution of the chemicals for
each quantitative data element, EPA selected ranges of toxicity values for each toxicity category
that differed based upon the type of data element used. For example, the range of toxicity values
that places a LOAEL in Toxicity Category 1 differs from the values used to place LDso values
into Toxicity Category 1. Placing contaminants into Toxicity Categories allows for a comparison
of the relative toxicity of contaminants that have different types of available data. Exhibit 2
displays the ranges for each non-cancer health effects data element and their respective Toxicity
Categories.
Page 4 of 11
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
Exhibit 2: Potency Measures for Universe Data Element Partitioned
Based on Toxicity (mg/kg/day or mg/kg)
Toxicity Category 1
Toxicity Category 2
Toxicity Category 3
Toxicity Category 4
Toxicity Category 5
RfD
<0.0001
0.0001 -<0.001
0.001 -<0.05
0.05 -<0.1
>0.1
NOAEL
<0.01
0.01 -< 1
1 -<10
10 -< 1000
>1000
LOAEL
<0.01
0.01 -<1
1 -<10
10-<1000
>1000
MRDD
<0.01
0.01 -<1
1 -<10
10 -< 1000
>1000
LDso
<1
1 -<50
50 - <500
500 - <5000
>5000
EPA used descriptive (or categorical) cancer data to group data elements into toxicity categories
that provide gradation based upon the strength of the data. Sources for the descriptive cancer data
included:
• US EPA Cancer Groupings
• International Agency for Research on Cancer (IARC) Cancer Groupings
• National Toxicology Program weight-of-evidence findings from cancer bioassays
• National Cancer Institute (NCI) weight-of-evidence findings from cancer bioassays
• EPA Water Disinfection By-Products with Carcinogenicity Estimates (DBF-CAN)
groupings based on carcinogenic potential derived from Quantitative Structure Activity
Relationship (QSAR) projections and expert judgment
EPA partitioned the cancer-related data elements in the Universe as described in Exhibit 3. The
cancer data placed chemicals in only the three highest Toxicity Categories. EPA did not use
quantitative measures of dose-response for carcinogenicity in the screening criteria because more
chemicals can be analyzed using the descriptive data than by cancer slope factors. In addition,
EPA did not use descriptors indicating lack of carcinogenic potential or insufficient data to
determine carcinogenic potential in categorizing chemicals because those descriptors apply only
to the cancer endpoint and do not consider non-cancer effects associated with exposure to the
chemical.
Page 5 of 11
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
Exhibit 3: Partitioning of Cancer Data Based on TD50 Values and
Weight of Evidence
Toxicity
Category 1
Toxicity
Category 2
Toxicity
Category 3
TDso
<0.1
0.1 -100
>100
EPA
Group A;
Human
Carcinogen
Groups B1 and
B2; Likely
carcinogens
Group C;
Suggestive
evidence of
carcinogenicity
IARC /HC
Group 1
Group 2A
Group 2B
NTP
CE 2 species/2
sexes; or 2
species; or 2
sexes
Combinations of
CE, SE, EE, and
NE
Combinations of
SE, EE, and NE
NCI
P 2 species/2
sexes; or 2
species; or 2
sexes
Combinations
ofP, EandN
Combinations
of E and N
DSS-Tox
H
HM
M and LM
** Cancer data placed chemicals in only the three highest Toxicity Categories
CE = clear evidence, SE = some evidence, EE = equivocal evidence, NE = no evidence P = positive, N = Negative, E
= equivocal
H = high probability, HM = high to medium probability, M = medium probability, LM = medium to low probability
EPA chose a conservative approach to categorize each chemical's toxicity for screening and
evaluated all the available health effects dose-response and categorical data elements for a given
chemical in the screening process. Chemicals were assigned to the highest toxicity category
indicated after an evaluation of all the available data. Accordingly, if a chemical had just one
data element that places it in Toxicity Category 1, it was categorized as such even if some of the
other data elements for that same chemical may place it in a lower toxicity category. For
example, if a chemical is classified as a 2A carcinogen by IARC it will be placed in Toxicity
Category 2 using the descriptive cancer data even if a quantified LOAEL from a different study
places it in Toxicity Category 3.
2.2 Occurrence Data Elements
EPA evaluated the occurrence data elements for each chemical and placed them on the horizontal
axis of the screening table. In assessing the data, EPA found that the data elements that represent
a chemical's potential to occur in drinking water vary greatly. EPA's goal was to determine
which data elements best represented the potential to occur in drinking water. EPA considered
and evaluated data elements in the following categories:
• Finished Water - measures of concentration and frequency of detections
• Ambient Water - measures of concentration and frequency of detections
• Total Releases in the Environment - pounds per year and number of states
• Pesticide Application Rates - pounds per year and number of states
• Production volume - pounds per year
In addition to evaluating quantitative data elements listed above, EPA also considered chemicals
with descriptive data based upon their likelihood of occurring in drinking water. Examples of
Page 6 of 11
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
descriptive occurrence data elements include characterization as a disinfection by-product or a
drinking water treatment chemical.
EPA used the following hierarchal approach to select the occurrence data element used to screen
a chemical:
Finished Water = Ambient Water > Environmental Release Data > Production Data.
The highest data elements in the hierarchy are the finished and ambient water data; the lowest is
production data. Environmental release data from TRI and pesticide application data occupy the
middle position in the hierarchy. EPA also decided that when multiple data values exist for the
chemicals within a given component of the hierarchy, the most conservative data value is used.
For example, in the case of a chemical that has finished water data and ambient water data, EPA
selected the highest available numerical concentration value as the occurrence screening data
element.
2.3 Selection of the PCCL
The last step in the screening process used the health effects and occurrence data elements shown
in Exhibit 4 to establish the PCCL. As mentioned earlier, the health data elements were grouped
into 5 toxicity categories and the highest toxicity category indicated after an evaluation of all the
available data for a particular chemical was used in screening. EPA selected the highest available
data element in the occurrence hierarchy to screen the contaminant. Because the chemicals were
evaluated using a hierarchical approach for their occurrence elements, EPA developed separate
criteria for each of the occurrence elements. EPA tested the screening criteria using a set of 200
chemicals including regulated and prior CCL chemicals and some chemicals from the Universe
that had fairly complete data for all of the occurrence data elements. EPA screened these test
chemicals and then adjusted the position of the PCCL selection line. In general, the PCCL
selection line was positioned so that regulated chemicals and most prior CCL chemicals would
be selected for the PCCL.
Exhibit 4: Criteria for a Chemical to Pass to the PCCL
Health Effects
Toxicity Category 1
Toxicity Category 2
Toxicity Category 3
Toxicity Category 4
Toxicity Category 5
Occurrence (by data type)
Finished/Ambient Water
Concentrations
All Concentrations
> 1 |jg/l
>10ug/l
>100ug/l
>1000ug/l
Release Amount
(per year)
All Amounts
>1 0,000 Ibs/yr
> 100, 000 Ibs/yr
> 1 M Ibs/yr
>10M Ibs/yr
Production Volume
(per year)
All Amounts
> 500,000 Ibs/yr
>10M Ibs/yr
> 50 M Ibs/yr
>100M Ibs/yr
Page 7 of 11
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
3.0 Screening the Nominated Chemicals from the CCL 4
Universe to the PCCL 4
EPA received nominations for 59 unique contaminants for the CCL 4 including 54 chemicals and
five microbials (see section 4.0). Forty three of the nominated chemicals were included in the
CCL 4 Universe. Forty of the nominated chemicals were previously included in the CCL 3
Universe, and were carried forward to the CCL 4 Universe. In addition to these forty, EPA has
added three nominated chemicals to the CCL 4 Universe (octylphenol ethoxylate, oxacillin and
virginiamycin) based on health effects and/or occurrence data that was newly available since the
development of the CCL 3. A complete list of the nominated contaminants for the CCL 4 can be
found in the support document: Summary of Nominations for the Fourth CCL (USEPA, 2015a).
EPA screened all of the nominated chemicals in the CCL 4 Universe according to the screening
criteria developed for CCL 3, and based on that evaluation; twenty of the nominated chemicals
were included in the PCCL 4. Eighteen of those 20 chemicals were also included in the PCCL 3,
and EPA added two new chemicals (manganese and nonylphenol) to the PCCL 4. The data used
to screen the nominated chemicals from the CCL 4 Universe to the PCCL 4, and whether or not
the chemical moved from the Universe to the PCCL 4 is shown in Appendix 1 of this document.
4.0 Summary of the CCL 3 Microbes Screening Process and
Screening of the Nominated Microbes from the CCL 4
Universe to the PCCL 4
The microbial CCL 3 Universe was defined as microbes that are known to cause disease in
humans. A literature review identified a list of 1,415 known human pathogens including
bacterial, viral, protozoan, helminth and fungal pathogens (Taylor et al., 2001). This list was
recommended as the basis of the microbial CCL 3 Universe. EPA requested nominations from
the public for additions to the microbial CCL 3 Universe, and two microbes and two viral groups
were added to the list through the nomination process (USEPA, 2006; USEPA, 2009e). EPA also
added six fungi that did not appear on the list of Taylor et al. (2001) but were identified in
drinking water distribution systems, thus bringing the total number of microbes in the CCL 3
Universe to 1,425 pathogens. These microbes remain in the CCL 4 Universe.
The National Academy of Science's National Research Council (NRC) workgroup report did not
make specific recommendations for selection and screening of microbial contaminants to a
PCCL, and because occurrence data for microbes are not readily available to support the
screening process envisioned by the NRC workgroup, the agency requested further study of these
issues by a workgroup convened by the National Drinking Water Advisory Council (NDWAC).
NDWAC recommended selecting microbial contaminants for the PCCL based upon an
assessment of occurrence attributes and health effects attributes relating to the plausibility of
pathogen presence, survival, and transport through drinking water resulting in disease
manifestations from drinking water exposure. These recommendations are described further in,
Page 8 of 11
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
National Drinking Water Advisory Council Report on the CCL Classification Process (NDWAC,
2004).
Selection of microbes from the CCL Universe for placement on the PCCL is based upon
exclusionary screening criteria that assess the potential of water-related transmission
(occurrence) and the plausibility of causing waterborne disease by ingestion, inhalation or
dermal contact (health effects). Microbes that met any of the exclusionary criteria were not
included on the PCCL. The screening criteria developed for CCL 3, which are listed below, were
also used for CCL 4.
Criterion 1: Anaerobes (microorganisms that cannot survive in oxygenated environments)
Criterion 2: Fastidious or obligate intracellular pathogens (environmental survival in water
implausible)
Criterion 3: Pathogens exclusively transmitted by direct or indirect contact with blood or body
fluids (including sexually transmitted diseases)
Criterion 4: Pathogens transmitted by vectors
Criterion 5: Microflora indigenous to the gastrointestinal tract, skin and mucous membranes
Criterion 6: Pathogens transmitted solely by respiratory secretions
Criterion 7: Pathogens whose life cycle is incompatible with drinking water transmission
Criterion 8: Pathogens where drinking water-related transmission is not implicated
Criterion 9: Natural habitat is in the environment without epidemiological evidence of drinking
water-related disease
Criterion 10: Pathogens not endemic to North America
Criterion 11: A genus and species or serotype may be chosen to represent a group of closely
related organisms
Criterion 12: Current taxonomy does not support the classification listed by Taylor et al. (2001).
Four of the five nominated microbial contaminants, with the exception of heterotrophic plate
count bacteria, (e.g. Vibrio cholerae, Toxoplasma gondii, Naegleria fowleri and Adenovirus)
were on the PCCL 3 and are being carried forward to the PCCL 4 since no new data were found
that would support a change to the contaminants listed in the PCCL 3. For additional information
on the screening process please see Final Contaminant Candidate List 3 Microbes: Screening to
the PCCL (USEPA, 2009f). For detailed information on the scoring protocols used to rank the
nominated pathogens on the PCCL to produce a CCL please see Final Contaminant Candidate
List 3 Microbes: PCCL to CCL Process (USEPA, 2009g) and for the most recent versions of the
Page 9 of 11
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
contaminant information sheets, which summarize the data used for scoring the microbial
contaminants nominated for CCL 4 see Contaminant Information Sheets for the Draft PCCL
4 Nominated Contaminants (USEPA, 2015c).
5.0 References
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
Taylor, L. H., S. M. Latham, and M. E. Woolhouse. 2001. Risk factors for human disease
emergence Philosophical Transactions of the Royal Society of London B. Vol. 356, pp. 983-989
(See electronic Appendix A, No. 1411, pp. 1-9).
USEPA. 2006. Request for Nominations of Drinking Water Contaminants for the Contaminant
Candidate List. Federal Register. Vol. 71. No. 199. p. 60704. October 16, 2006.
USEPA. 2009a. Drinking Water Contaminant Candidate List 3—Final Notice. Federal Register.
Vol. 74. No 194. p. 51850. October 8, 2009.
USEPA. 2009b. Final Contaminant Candidate List 3 Chemicals: Identifying the Universe.
EPA 815-R-09-006. August, 2009.
USEPA. 2009c. Final Contaminant Candidate List 3 Chemicals: Screening to a PCCL.
EPA 815-R-09-007. August, 2009.
USEPA. 2009d. Final Contaminant Candidate List 3 Chemicals: Classification of PCCL to the
CCL. EPA 815-R-09-008. August 2009.
USEPA. 2009e. Final Contaminant Candidate List 3 Microbes: Identifying the Universe.
EPA 815-R-09-008. August 2009.
USEPA. 2009f. Final Contaminant Candidate List 3 Microbes: Screening to the PCCL.
EPA 815-R-09-008. August 2009.
USEPA. 2009g. Final Contaminant Candidate List 3 Microbes: PCCL to CCL Process.
EPA 815-R-09-009. August, 2009.
USEPA, 2012. Request for Nominations of Drinking Water Contaminants for the Fourth
Contaminant Candidate List. Federal Register. Vol. 77. No 89. p. 27057. May 8, 2012
USEPA. 2014. Announcement of Preliminary Regulatory Determination for Contaminants on
the Third Drinking Water Contaminant Candidate List. Federal Register. Vol. 79, No. 202, p.
62716, October 20, 2014.
Page 10 of 11
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
USEPA. 2015a. Summary of Nominations for the Fourth Contaminant Candidate List. EPA 815-
R-l5-001. January, 2015.
USEPA. 2015b. Data Sources for the CCL 4. EPA 815-R-15-004. January, 2015.
USEPA. 2015c. Contaminant Information Sheets (CISs) for the Draft Fourth Preliminary
Contaminant Candidate List (PCCL 4) Nominated Contaminants. EPA 815-R-15-003. January,
2015.
Page 11 of 11
-------
EPA-OGWDW Screening Document for the Draft EPA 815-R-15-002
PCCL 4 Nominated Contaminants
6.0 Appendices
Appendix 1. Screening data for the Nominated Chemicals in the
CCL 4 Universe
Appendix 1 presents the CASRN, names of the nominated contaminants in the CCL 4 Universe,
the health effects and occurrence data elements that were used in their screening. The CCL 4
Screening Notes column includes a brief explanation of whether or not the chemical made the
PCCL 4, and if it did not make the PCCL 4, the reason is included (i.e., the chemical failed based
on the screening criteria, or incomplete data were available, so the chemical could not be
screened). Some chemicals had some type of occurrence/ health information that allowed them to
be included in the CCL 4 Universe, but this data was not sufficient for screening. An example of
this is a chemical that was an analyte in a supplemental occurrence study, but was not detected;
therefore, no concentration value was available to be used in the screening process. Thus, this
chemical would remain in the Universe. The screening process is summarized in the text of this
report, and a detailed description of the screening process developed under CCL 3 can be found
in the Final CCL 3 Chemicals: Screening to a PCCL (USEPA, 2009c).
When the health effects data element is designated as Cancer Studies NTP, the results shown are
from cancer assays for two species and two sexes (male rat/female rat/ male mouse/female
mouse) The NTP cancer data were partitioned into Toxicity Categories as described in Exhibit 3
of this document and the data source is described further in USEPA, 2009b. For the occurrence
data elements, the release data may be either national TRI data or pesticide application data. The
notation "FW/AW" indicates the data are finished or ambient water data. Also noted, for some
contaminants, supplemental data were used.
Further data and information for the nominated contaminants that made the PCCL 4 are
available in the Contaminant Information Sheets (USEPA, 2015c) available in the CCL 4 water
docket and on the CCL 4 Web site at: http://www2.epa.gov/ccl/contaminant-candidate-list-4-
ccl-4.
PageA1-1
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
Appendix 1. Screening Data for the Nominated Chemicals in the CCL 4 Universe
Substance
Key
74233
6535
3200
28242
2918
12023
3168
2448
12375
14098
3122
5106
3114
CASRN
77439760
319846
86500
25057890
80057
1 689845
85687
63252
1 897456
2921882
84742
115322
84617
Common Name
3-chloro-4-
dichloromethyl-5-
hydroxy-2(5H)-
furanone
alpha-
Hexachlorocyclohe
xane
Azinphos-methyl
Bentazon
Bisphenol A (BPA)
Bromoxynil
Butyl benzyl
phthalate
Carbaryl
Chlorothalonil
Chlorpyrifos
Dibutyl phthalate
Dicofol
Dicyclohexyl
phthalate
Health Effect/Toxicity Data Used For CCL 4 Screening
Health Effect Data
Element
Lethal Dose 50 (LD50)
Risk Specific Dose (RSD)
Lowest Observed
Adverse Effect Level
(LOAEL)
Reference Dose (RfD)
Lowest Observed
Adverse Effect Level
(LOAEL)
Reference Dose (RfD)
Cancer Studies, NTP
Lowest Observed
Adverse Effect Level
(LOAEL)
Cancer Studies, NTP
Reference Dose (RfD)
Tolerable Daily Intake
(TDI)
Tumorigenic Dose 50
(TD50)
No HE data for screening
Value
120
0.000002
0.91
0.03
2.5
0.015
IS/P/P/N
0.23
P/P/N/N
0.0003
0.063
32.9
Units
mg/kg
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
Data
Source
RTECS
ITER
RTECS
OPP
RTECS
OPP
NTP
RTECS
NTP
OPP
ITER
DSSTOX
Toxicity
Screening
Category
Toxicity
Category 3
Toxicity
Category 1
Toxicity
Category 2
Toxicity
Category 3
Toxicity
Category 3
Toxicity
Category 3
Toxicity
Category 2
Toxicity
Category 2
Toxicity
Category 1
Toxicity
Category 2
Toxicity
Category 4
Toxicity
Category 2
Occurrence Data Used For CCL 4 Screening
Occurrence Data
Element
No Occurrence data
for screening
FW/AW-Max Value
FW/AW-Max Value
FW/AW-Max Value
FW/AW-Max Value
FW/AW-Max Value
Production Volume
FW/AW-Max Value
FW/AW-Max Value
FW/AW-Max Value
Release
Release
Production Volume
Value
0.21
3.37
11.46
12
6.1
>50M-100M
33.5
0.71
0.57
177,489
788,527
>500K- 1M
Units
ug/L
ug/L
ug/L
ug/L
ug/L
Ibs/yr
ug/L
ug/L
ug/L
Ibs/yr
Ibs/yr
Ibs/yr
Data Source
NAWQA
NAWQA
NAWQA
Kolpin et al.,
2002 (Max)
NAWQA
CUS/IUR
NAWQA
NAWQA
NAWQA
TRI
NCFAP
CUS/IUR
CCL 4 Screening
Notes
Incomplete data for
screening/ remains
in CCL 4 Universe
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Fails Screen/
remains in CCL 4
Universe
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
Makes PCCL 4
Incomplete data for
screening/ remains
in CCL 4 Universe
A1-2
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
Substance
Key
3118
30533
5769
5200
5104
12839
6584
5402
18823
6419
11918
76859
28410
20331
CASRN
84662
28553120
131113
117840
115297
2164172
330552
1 21 755
7439965
298000
1 634044
1 01 043372
251 54523
901 6459
Common Name
Diethyl phthalate
Di-isononyl
phthalate
Dimethyl phthalate
Di-n-octyl
phthalate
Endosulfan
Fluometuron
Linuron
Malathion
Manganese
Methyl parathion
Methyl tert-butyl
ether
Microcystin-LR
Nonylphenol
Nonylphenol
ethoxylate
Health Effect/Toxicity Data Used For CCL 4 Screening
Health Effect Data
Element
No Observed Adverse
Effect Level (NOAEL)
Lowest Observed
Adverse Effect Level
(LOAEL)
Reference Dose (RfD)
Reference Dose (RfD)
No Observed Adverse
Effect Level (NOAEL)
Reference Dose (RfD)
Lowest Observed Effect
Level (LOEL)
No Observed Effect Level
(NOEL)
No Observed Adverse
Effect Level (NOAEL)
Reference Dose (RfD)
Tolerable Daily Intake
(TDI)
Reference Dose (RfD)
Lowest Observed
Adverse Effect Level
(LOAEL)
Lethal Dose 50 (LD50)
Value
750
402
10
0.04
0.7
0.01
0.63
0.23
0.14
0.0002
0.01
0.000003
2
1310
Units
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg
Data
Source
ITER
RTECS
RAIS
RAIS
ITER
EPA HA
ITER
ITER
ITER
EPA HA
ITER
Ueno et
al., 1999
RTECS
RTECS
Toxicity
Screening
Category
Toxicity
Category 4
Toxicity
Category 4
Toxicity
Category 5
Toxicity
Category 3
Toxicity
Category 2
Toxicity
Category 3
Toxicity
Category 2
Toxicity
Category 2
Toxicity
Category 2
Toxicity
Category 2
Toxicity
Category 3
Toxicity
Category 1
Toxicity
Category 3
Toxicity
Category 4
Occurrence Data Used For CCL 4 Screening
Occurrence Data
Element
FW/AW-Med Value
Production Volume
Release
Production Volume
Release
FW/AW-Max Value
FW/AW-Max Value
FW/AW-Max Value
FW/AW
FW/AW-Max Value
FW/AW-Max Value
FW/AW
FW/AW-Max Value
FW/AW-Median
Value
Value
0.2
>10M-50M
41 4093
>1M-10M
1 ,604,700
37.8
1.4
9.58
1,314
0.521
23,000
1,200
40
1
Units
ug/L
Ibs/yr
Ibs/yr
Ibs/yr
Ibs/yr
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
Data Source
NREC
CUS/IUR
TRI
CUS/IUR
NCFAP
NAWQA
NAWQA
NAWQA
NIRS
NAWQA
NAWQA
AWWARF,
2001 (Max)
Kolpin et al.,
2002 (Max)
NREC
CCL 4 Screening
Notes
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Fails Screen/
remains in CCL 4
Universe
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Fails Screen/
remains in CCL 4
Universe
A1-3
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
Substance
Key
29943
20418
81717
75565
6614
35815
9544
2334
2343
2202
4164
14798
CASRN
271 93288
90361 95
66795
61336
335671
52645531
732116
57830
58220
52686
1 01 202
3380345
Common Name
Octylphenol
Octylphenol
ethoxylate
Oxacillin
Penicillin
Perfluorooctanoic
acid (PFOA)
Permethrin
Phosmet
Progesterone
Testosterone
Trichlorfon
Triclocarban
Triclosan
Health Effect/Toxicity Data Used For CCL 4 Screening
Health Effect Data
Element
No HE data for screening
Lethal Dose 50 (LD50)
Maximum Recommended
Daily Dose (MRDD)
Maximum Recommended
Daily Dose (MRDD)
Lowest Observed
Adverse Effect Level
(LOAEL)
No Observed Effect Level
(NOEL)
Lethal Dose 50 (LD50)
Acceptable Daily Intake
(ADI)
Acceptable Daily Intake
(ADI)
Reference Dose (RfD)
No Observed Adverse
Effect Level (NOAEL)
Lethal Dose 50 (LD50)
Value
3500
100
25
0.46
5
26
0.03
0.002
0.002
25
3700
Units
mg/kg
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg
Data
Source
RTECS
DSSTOX
DSSTOX
Lau et al.,
2006
ITER
RTECS
JECFA
JECFA
OPP
OCSPP
RTECS
Toxicity
Screening
Category
Toxicity
Category 4
Toxicity
Category 4
Toxicity
Category 4
Toxicity
Category 2
Toxicity
Category 3
Toxicity
Category 2
Toxicity
Category 3
Toxicity
Category 3
Toxicity
Category 3
Toxicity
Category 4
Toxicity
Category 4
Occurrence Data Used For CCL 4 Screening
Occurrence Data
Element
Production Volume
Production Volume
No Occurrence data
for screening
No Occurrence data
for screening
FW/AW
Release
Release
FW/AW
FW/AW
Release
Production Volume
FW/AW-Median
Value
Value
>10M-50M
< 500,000
Ibs
7.2
1 ,068,390
1 ,336,387
0.199
0.214
861
>1M-10M
0.19
Units
Ibs/yr
Ibs/yr
ug/L
Ibs/yr
Ibs/yr
ug/L
ug/L
Ibs/yr
Ibs/yr
ug/L
Data Source
CUS/IUR
CUS/IUR
Emmett et
al., 2006
(Max)
NCFAP
NCFAP
Kolpin et al.,
2002 (Max)
Kolpin et al.,
2002 (Max)
TRI
CUS/IUR
NREC
CCL 4 Screening
Notes
Incomplete data for
screening/ remains
in CCL 4 Universe
Fails Screen/
remains in CCL 4
Universe
Incomplete data for
screening/ remains
in CCL 4 Universe
Incomplete data for
screening/ remains
in CCL 4 Universe
Makes PCCL 4
Makes PCCL 4
Makes PCCL 4
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
Fails Screen/
remains in CCL 4
Universe
A1-4
-------
EPA-OGWDW
Screening Document for the Draft
PCCL 4 Nominated Contaminants
EPA 815-R-15-002
Substance
Key
75792
75932
CASRN
1401690
11006761
Common Name
Tylosin
Virginiamycin
Health Effect/Toxicity Data Used For CCL 4 Screening
Health Effect Data
Element
Lethal Dose 50 (LD50)
No HE data for screening
Value
800
Units
mg/kg
Data
Source
RTECS
Toxicity
Screening
Category
Toxicity
Category 4
Occurrence Data Used For CCL 4 Screening
Occurrence Data
Element
FW/AW-Median
Value
No Occurrence data
for screening
Value
0.04
Units
ug/L
Data Source
NREC
CCL 4 Screening
Notes
Fails Screen/
remains in CCL 4
Universe
Incomplete data for
screening/ remains
in CCL 4 Universe
AWWARF - Carmichael, W.W. 2001. Assessment of Blue-Green Algal Toxins in Raw and Finished Drinking Water. Denver, CO: American Waterworks Association Research
Foundation
CUS/IUR - Chemical Update System/ Inventory Update Rule
DSSTOX- Distributed Structure-Searchable Toxicity Database Network
Emmett et al., 2006 - Emmett, et al., 2006. J. Occ. Env. Med. Little Hocking, OH
EPA HA - EPA Health Advisory
ITER - International Toxicity Estimates for Risk
JECFA - Joint FAO/WHO Expert Committee on Food Additives
Kolpinetal.,2002-Kolpin, D.W., etal.,2002. Env. Sci. STechnol., 36(6), pp. 1202-1211.
Lau et al., 2006 - Lau, 2006. Tox. Sci., 90, 2, pp. 510-518.
NAWQA - National Water Quality Assessment
NCFAP - National Center for Food and Agricultural Policy
NIRS - National Inorganics and Radionuclides Survey
NREC - National Reconnaissance of Emerging Contaminants
NTP - National Toxicology Program; Values: P=positive; N=negative; IS=insufficient study. Results for male rat/female rat/male mouse/female mouse.
OCSPP - Office of Chemical Safety and Pollution Prevention
OPP - Office of Pesticide Programs
RAIS - Risk Assessment Information System
RTECS - Registry of Toxic Effects of Chemical Substances
TRI - Toxics Release Inventory
UCM Round 1 - Unregulated Contaminant Monitoring
Ueno et al., 1999 - Ueno, Y., Y. Makita, S. Nagata et al. 1999. Environ. Toxicol. 14(1):45-55
A1-5
------- |