# Screening Document for the Draft PCCL 4 Nominated Contaminants

## Office of Water (4607M)

EPA 815-R-1 5 -00 2 January 201 5EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



# 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 ............................................................................................................................ A1 Appendix 1. Screening data for the Nominated Chemicals in the CCL 4 Universe ................ A1

Page i of viEPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002

Page ii of viEPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



# Exhibits

Exhibit 1: Partition for Screening the Universe .............................................................................. 4 Exhibit 2: Potency Measures for Universe Data Element Partitioned Based on Toxicity (mg/kg/day or mg/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 iii of viEPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002

Page iv of viEPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



# Acronyms and Abbreviations

< L ess than

< L ess than or equal to

> G reater than

> G reater than or equal to

μ M icrogram, one μg/L M icrograms per liter
ADI Acceptable Daily Intake
AWWA RF 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
DBP

- 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 G ram H High probability of causing cancer
HM High moderate probability of causing cancer
IARC I nternational Agency for Research on Cancer
ITER International Toxicity Estimates for Risk
JECFA Joint FAO/WHO Expert Committee on Food Additives kg K ilogram
L Liter
LD 50 

## 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 viEPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



## MCLG Maximum Contaminant Level Goal mg/kg Milligrams per kilogram body weight mg/kg/day Milligrams per kilogram body weight per day mg/L M illigrams per liter
MRDD Maximum Recommended Daily Dose
N Negative NAWQA National Water Quality Assessment
NE No evidenc e of carcinogenicity
NIRS National Inorganics and Radionuclides Survey
NOAEL No Observed Adverse Effect Level
NCI National Cancer Institute
NCFAP National Center for Food and Agricultural Policy
NDWAC National Drinking Water Advisory Council
NRC National Academy of Science’s National Research Council
NREC National Reconnaissance of Emerging Contaminants
NTP National Toxicology Program
OPP Office of Pesticide Programs
P Positive
PFOA Perfluorooctanoic acid
PWS P ublic water system QSAR Quantitative Structure Activity Relationship
RfD R eference dose
RAIS Risk Assessment Information System
RTECS Registry of Toxic Effects of Chemical Substances
SDWA Safe Drinking Water Act
SE Some evidence of carcinogenicity
TD 50 

## 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.
TRI Toxics Release Inventory
UCM Round 1 Unregulated Contaminant Monitoring Round 1
US United States of America
WHO World Health Organization

yr Y ear

Page vi of viEPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



# 1.0 Introduction

Sec tion 1412(b)(1) of the Safe Drinking Water Act ( SDWA ), 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 contam inants 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 th at 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, 2009 a )). In developing the CCL 3, EPA implemented a multi

- ste p process to select contaminants for the final CCL 3, which included the following key steps:

(1) Th e identification of a broad universe of potential drinking water contaminants (CCL 3 Universe); (2) Screening the CCL 3 Universe to a Preliminary CCL (PCC L) 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 classifi cation 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/contaminantcandidate- 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)(1)(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 determinat ions

. This is

Page 1 of 11EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



## 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 Goal 1 

## (MCLG) and NPDWR 2 

## . After the proposal, the agency has 18 months to publish and promulgate a final MCLG and NPDWR (SDWA section 1412(b)(1)(E)) 3



## .
On February 11, 2011, as a s eparate a cti on, the a gency issue d a pos itive r egulatory dete rmination for pe rchlorate, a c hemical l isted i n 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 F R 62716 (USEPA, 2014)). The five contaminants include: dimethoate; 1,3- dinitrobenzene; strontium; t erbufos a nd terbufos s ulfone. The a gency is m aking preliminary de terminations to re gula te one c ontaminant (strontium) and to not regulate f

our

c ontaminants ( dimethoate; 1,3- dinitrobenzene; t erbuf os; a nd terbufos s ulfone). Therefore, the agency is removing perchlorate a nd these f ive c ontaminants f

rom t he D raft F ourth CCL ( CCL 4)

, pending the result of t he final r egulatory determinations f or CCL 3.

EPA conduc ted an abbreviated evaluation and select ion 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 heal th goals." (40 C.F.R. 141.2; 42 U.S.C. 300g

- 1)

2 

### An NPDWR is a legally enforceable standard that applies to public water systems. An NPDWR sets a legal limit (called a maximum contaminant level or MCL) or specifies a certain treatment technique (TT) for public water systems for a specific contaminant or group of contaminants. The MCL is the highest level of a contaminant that is allowed in drinking water and is set as close to the MCLG as feasible using the best available treatment technology and analytical methods and taking cost into consideration.

3 

### The statute authorizes a nine month extension of this promulgation date



## .

Page 2 of 1 1EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



## to occur in public w ater s ystems. EPA r eviewe d the nom inations a nd sup porting information provided by nominators to determine i f a ny new da ta w ere p rovided that h ad not be e n previously evaluated for C CL 3. The a gency also collected additional da ta f or t he no minated contaminants, when it w as available, from bot h CCL 3 data s ources that ha d be en updated and from new da ta

sour ces that were not

ava ilable at the time of

C CL 3. A co mplete list of r eferences provided by nominators can be found in the support document Summary of Nominations for the Fourth CCL (USEPA, 2 01 5a ). A mo re detailed d escription o f t he CCL d ata sources collected b y E PA may b e found in the support document Data Sources for the CCL 4 ( USEPA, 2 01 5b ). EPA ev aluated t he nominated contaminants ut ilizi ng the be st a vailable he alth effects a nd occurrence da ta a nd the

s ame process f

or s creening and scoring contaminants t hat w as us ed 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 a gency 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 supp ort 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 he alth 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 oc currence 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 an d 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 se t 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 11EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



## environmental rel ease and production volume. EPA then used these criteria to select chemicals for the PCCL for further consideration.



# Exhibit 1: Partition for Screening the Universe

Heal th Effects Occurrence blank Low to High Occurrence

Incr easing Toxicity Do not pass to PCCL Pass 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, LD 50 

## ) 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 chemi cals for each quantitative data element, EPA selected ranges of toxicity values for each toxicity cat egory 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 LD 50 

## 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- can c er health effects data element and their respective Toxicity Categories.

Page 4 of 11EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



# Exhi bit 2: Potency Measures for Universe Data Element Partitioned Based on Toxicity (mg/kg/day or mg/kg)

blank blank RfD NOAEL LOAEL MRDD LD 50 Toxicity Category 1 <0.0001 <0.01 <0.01 <0.01 <1
Toxicity Category 2 0.0001 - <0.001 0.01 - < 1 0.01 - <1 0.01 - < 1 1 - <50
Toxicity Category 3 0.001 - <0.05 1 - <10 1 - <10 1 - <10 50 - <500
Toxicity Category 4 0.05 - <0.1 10 - < 1000 10 - <1000 10 - < 1000 500 - <5000
Toxicity Category 5 ≥0.1 ≥1000 ≥1000 ≥1000 ≥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 EP A Cancer Groupings

• International Agency fo r Research on Cancer ( IARC ) Cancer Groupings

• N ational 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 Carcinogeni city Estimates (DBP

- 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
q uantitative 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 d escriptors indicat ing 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 11EPA- 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

blan blank k TD 50 EPA IARC /HC NTP NCI DSS

- Tox

Toxicity Category 1 <0.1 Group A; Human Carcinogen Group 1 CE 2 species/2 sexes; or 2 species; or 2

sexes P 2 species/2 sexes; or 2 species; or 2

sexes H

Toxicity Category 2 0.1 - 100 Groups B1 and B2; Likely carcinogens Group 2A Combinations of CE, SE, EE, and NE Combinations of P, E and N HM

Toxicity Category 3 >100 Group C; Suggestive evidence of carcinogenicity Group 2B Combinations of SE, EE, and NE Combinations of E and N 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 chemica l’s toxicity for screening and evaluated a ll 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 a ll 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 assess ing the data, EPA found that the data elements that represent a chemical’s potential to occur in drinking water vary greatly. E PA’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:

• Fin ished Water – measures of concentration and frequency of detections

• Ambie nt 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 addi tion 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 11EPA- 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 us ed the following hierarchal approach to select the occurrence data element used to screen a chemical:

Fin ished Water = Ambient Water > Environmental Release Data > Production Data.

The highest d ata 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 v alues 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 conc entration value as the occurrence screening data element.



# 2.3 Selection of the PCCL

The last step in the screening process use d 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 t he highest available data element in t he 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 usin g 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 se lection 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 Occur rence (by data type)
blank Finished/Ambient Water Concentrations Release Amount (per year) Production Volume (per year) Toxicity Category 1 All Concentrations All Amounts All Amounts Toxicity Category 2 ≥ 1 μ g/l ≥ 10,000 lbs/yr ≥ 500,000 lbs/yr Toxicity Category 3 ≥ 10 μ g/l ≥ 100,000 lbs/yr ≥ 10 M lbs/yr Toxicity Category 4 ≥ 100 μ g/l ≥ 1 M lbs/yr ≥ 50 M lbs/yr Toxicity Category 5 ≥ 1000 μ g/l ≥ 10 M lbs/yr ≥ 100 M lbs/yr

Page 7 of 11EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



# 3.0 Screening the Nominated Chemicals from the CCL 4 Universe to the PCCL 4

EPA r eceived nominations f or 59 unique c ontaminants f or t he C CL 4 including 54 chemicals a nd five m icrobials (see s ec tion 4.0). Forty three of t he nom inated chemicals w ere i ncluded in the CCL 4 Universe. Forty of t he nom inated chemicals w ere pr eviously included in the CCL 3 Universe, and were c arried forward to the C CL 4 Universe. In addition to t hese f ort y, EPA ha s added t hree nominated c hemicals to t he CCL 4 U niver se (octylphenol e thoxylate, oxacillin and virginiamycin) ba sed on healt h effects a nd/or oc currence da ta t hat w as newly ava ilable sinc e 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, 201 5a ).

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 U niverse 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). Th is 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 U niverse, 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 n umber of microbes in the CCL 3 U niverse to 1,4 25 pathogens. These microbes remain in the CCL 4 Universe.

The National Academy of Science’s National Research Council ( NRC ) wo rkgroup 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 a gency 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 a ttributes 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 11EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



## National Drinking Water Advisory Council Report on the CCL Classification Process (NDWAC, 2004).

Sele c tion of microbes from the CCL Universe for placement on the PCCL is based upon exclusionary screening criteria that assess the p otential 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 crit eria developed for CCL 3, which are listed below, were also used for CCL 4

.

Crite rion 1: Anaerobes (microorganisms that cannot survive in oxygenated environments)

Crite rion 2: F astidious or obligate intracellular pathogens (environmental survival in water implausible)

Crite rion 3: Pathogens exclusively transmitted by direct or indirect contact with blood or body fluids (including sexually transmitted diseases)

Crite rion 4: Pathogens transmitted by vectors

Crite rion 5: Microflora indigenous to the gastr ointestinal tract, skin and mucous membranes

Crite rion 6: Pathogens transmitted solely by respiratory secretions

Crite rion 7: Pathogens whose life cycle is incompatible with drinking water tr ansmission

Crite rion 8: Pathogens where drinking water- related transmission is not implicated

Crite rion 9 : Natural habitat is in the environment without epidemiological evidence of drinking
water

- related disease

Crite rion 10: Pathogens not endemic to North America

Crite rion 11: A genus and species or serotype may be chosen to represent a group of closely related organisms

Crite rion 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, 2009 f). For detailed information on the scoring protocols used to rank the nominated pathogens on the PCCL to produce a C CL 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 11EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



## contaminant i nformation sheets, w hich su mmarize the data used f or scor ing the m icrobial contaminants nominated for CCL 4 s ee Contaminant Information Sheets for the Draft PCCL 4 Nominated Contaminants (USEPA, 201 5c ).



# 5 .0 References

Nati onal 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 App endix A, No. 1411, pp. 1-9).

USEP A. 2006. Request for Nominations of Drinking Water Contaminants for the Contaminant Cand idate L ist. Federal Register . Vol. 71. No. 199. p. 60704. October 16, 2006.

USEP A. 2009a. Drinking Water Contaminant Candidate List 3— Final Notice. Federal Register. Vol. 74. No 194. p. 51850. October 8, 2009.

USEP A. 2009b. Final Contaminant Candidate List 3 Chemicals: Identifying the Universe. EPA 815-R-09-006. August, 2009.

USEP A. 2009c. Final Contaminant Candidate List 3 Chemicals: Screening to a PCCL. EPA 815-R-09-007. August, 2009.

USEPA. 2 009 d . Final Contaminant Candidate List 3 Chemicals: Classification of PCCL to the CCL

. EPA 815 -R-09- 008 . August 2009.

USEPA. 2 009 e. Final Contam inant Candidate List 3 Microbes: Identifying the Universe. EPA 815-R-09-008. August 2009.

USEPA. 2 009 f. Final Contam inant Candidate List 3 Microbes: Screening to the PCCL. EPA 815-R-09-008. August 2009.

USEP A. 2009g. Final Contaminant Candidate List 3 Microbes: PCCL to CCL Process. EPA 815-R-09-009. August, 2009.

USEPA, 2 012 . 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 T hird Drinking Water C ontaminant C andidate L ist. Federal R egister . Vol. 79, No. 202, p. 62716, October 20, 2014.

Page 10 of 11EPA- 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 L ist . EPA 815- R-15-001. 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 11EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002



# 6 .0 Appendices

Appendix 1. Screening data for the Nominated Chemicals in the CCL 4 Universe

Appendi x 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 availab l e, 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 t he h ealth effects data e lement 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 o ccurrence data elements, the r elease 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 u sed.

Further data and information for the nominated contaminants that made the PCCL 4 are available in the Contaminant Information Sheets (USEPA, 201 5c ) a v ailabl e i n t h e C CL 4 w ater d ocket and on the CCL 4 Web site at: http://www2.epa.gov/ccl/contaminant-candidate-l ist -4- ccl -4

.

Page A1 -1EPA- 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

blank blank blank blan k bla nk Health Effect/Toxicity Data Used For CCL 4 Screening bla nk bla nk bl

a
n k Occurrence Data Used For CCL 4 Screening bl

a
n k bl

an k b blank

Substance Key CASRN Common Name Health Effect Data Element Value Units Data Source Toxicity Screening Category Occurrence Data Element Value Units Data Source CCL 4 Screening Notes

74233 77439760 3

- chloro

- 4

- dichloromethyl-5- hydroxy- 2(5H)

- furanone Lethal Dose 50 (LD50) 120 mg/kg RTECS Toxicity Category 3 No Occurrence data for screening blank blank blank Incomplete data for screening/ remains in CCL 4 Universe

6535 319846 alpha

Hexachlorocyclohe

xane Risk Specific Dose (RSD) 0.000002 mg/kg-day ITER Toxicity Category 1 FW/AW -Max Value 0.21 ug/L NAWQA Makes PCCL 4

3200 86500 Azinphos-methyl Lowest Observed Adverse Effect Level (LOAEL) 0.91 mg/kg-day RTECS Toxicity Category 2 FW/AW -Max Value 3.37 ug/L NAWQA Makes PCCL 4

28242 25057890 Bentazon Reference Dose (RfD) 0.03 mg/kg-day OPP Toxicity Category 3 FW/AW -Max Value 11.46 ug/L NAWQA Makes PCCL 4

2918 80057 Bisphenol A (BPA) Lowest Observed Adverse Effect Level (LOAEL) 2.5 mg/kg-day RTECS Toxicity Category 3 FW/AW -Max Value 12 ug/L Kolpin et al., 2002 (Max) Makes PCCL 4

12023 1689845 Bromoxynil Reference Dose (RfD) 0.015 mg/kg-day OPP Toxicity Category 3 FW/AW -Max Value 6.1 ug/L NAWQA Fails Screen/ remains in CCL 4 Universe

3168 85687 Butyl benzyl phthalate Cancer Studies, NTP IS/P/P/N blank NTP Toxicity Category 2 Production Volume >50M - 100M lbs/yr CUS/IUR Makes PCCL 4

2448 63252 Carbaryl Lowest Observed Adverse Effect Level (LOAEL) 0.23 mg/kg-day RTECS Toxicity Category 2 FW/AW-Max Value 33.5 ug/L NAWQA Makes PCCL 4

12375 1897456 Chlorothalonil Cancer Studies, NTP P/P/N/N blank NTP Toxicity Category 1 FW/AW -Max Value 0.71 ug/L NAWQA Makes PCCL 4

14098 2921882 Chlorpyrifos Reference Dose (RfD) 0.0003 mg/kg-day OPP Toxicity Category 2 FW/AW -Max Value 0.57 ug/L NAWQA Fails Screen/ remains in CCL 4 Universe

3122 84742 Dibutyl phthalate Tolerable Daily Intake (TDI) 0.063 mg/kg-day ITER Toxicity Category 4 Release 177,489 lbs/yr TRI Fails Screen/ remains in CCL 4 Universe

5106 115322 Dicofol Tumorigenic Dose 50 (TD50) 32.9 mg/kg-day DSSTOX Toxicity Category 2 Release 788,527 lbs/yr NCFAP Makes PCCL 4

3114 84617 Dicyclohexyl phthalate No HE data for screening blank blank blank blank Production Volume >500K - 1M lbs/yr CUS/IUR Incomplete data for screening/ remains in CCL 4 Universe

A1-2EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002

blank blank blank blan k bla nk Health Effect/Toxicity Data Used For CCL 4 Screening bla nk bla nk bl

a
n k Occurrence Data Used For CCL 4 Screening bl

a
n k bl

an k b blank

Substance Key CASRN Common Name Health Effect Data Element Value Units Data Source Toxicity Screening Category Occurrence Data Element Value Units Data Source CCL 4 Screening Notes

3118 84662 Diethyl phthalate No Observed Adverse Effect Level (NOAEL) 750 mg/kg-day ITER Toxicity Category 4 FW/AW -Med Value 0.2 ug/L NREC Fails Screen/ remains in CCL 4 Universe

30533 28553120 Di-isononyl phthalate Lowest Observed Adverse Effect Level (LOAEL) 402 mg/kg-day RTECS Toxicity Category 4 Production Volume >10M - 50M lbs/yr CUS/IUR Fails Screen/ remains in CCL 4 Universe

5769 131113 Dimethyl phthalate Reference Dose (RfD) 10 mg/kg-day RAIS Toxicity Category 5 Release 414093 lbs/yr TRI Fails Screen/ remains in CCL 4 Universe

5200 117840 Di-n- octyl phthalate Reference Dose (RfD) 0.04 mg/kg-day RAIS Toxicity Category 3 Production Volume >1M - 10M lbs/yr CUS/IUR Fails Screen/ remains in CCL 4 Universe

5104 115297 Endosulfan No Observed Adverse Effect Level (NOAEL) 0.7 mg/kg-day ITER Toxicity Category 2 Release 1,604,700 lbs/yr NCFAP Makes PCCL 4

12839 2164172 Fluometuron Reference Dose (RfD) 0.01 mg/kg-day EPA HA Toxicity Category 3 FW/AW -Max Value 37.8 ug/L NAWQA Makes PCCL 4

6584 330552 Linuron Lowest Observed Effect Level (LOEL) 0.63 mg/kg-day ITER Toxicity Category 2 FW/AW -Max Value 1.4 ug/L NAWQA Makes PCCL 4

5402 121755 Malathion No Observed Effect Level (NOEL) 0.23 mg/kg-day ITER Toxicity Category 2 FW/AW -Max Value 9.58 ug/L NAWQA Makes PCCL 4

18823 7439965 Manganese No Observed Adverse Effect Level (NOAEL) 0.14 mg/kg-day ITER Toxicity Category 2 FW/AW 1,314 ug/L NIRS Makes PCCL 4

6419 298000 Methyl parathion Reference Dose (RfD) 0.0002 mg/kg-day EPA HA Toxicity Category 2 FW/AW -Max Value 0.521 ug/L NAWQA Fails Screen/ remains in CCL 4 Universe

11918 1634044 Methyl tert-butyl ether Tolerable Daily Intake (TDI) 0.01 mg/kg-day ITER Toxicity Category 3 FW/AW -Max Value 23,000 ug/L NAWQA Makes PCCL 4

76859 101043372 Microcystin

- LR Reference Dose (RfD) 0.000003 mg/kg-day Ueno et al., 1999 Toxicity Category 1 FW/AW 1,200 ug/L AWWARF, 2001 (Max) Makes PCCL 4

28410 25154523 Nonylphenol Lowest Observed Adverse Effect Level (LOAEL) 2 mg/kg-day RTECS Toxicity Category 3 FW/AW -Max Value 40 ug/L Kolpin et al., 2002 (Max) Makes PCCL 4

20331 9016459 Nonylphenol ethoxylate Lethal Dose 50 (LD50) 1310 mg/kg RTECS Toxicity Category 4 FW/AW -Median Value 1 ug/L NREC Fails Screen/ remains in CCL 4 Universe

A1-3EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002

blank blank blank blan k bla nk Health Effect/Toxicity Data Used For CCL 4 Screening bla nk bla nk bl

a
n k Occurrence Data Used For CCL 4 Screening bl

a
n k bl

an k b blank

Substance Key CASRN Common Name Health Effect Data Element Value Units Data Source Toxicity Screening Category Occurrence Data Element Value Units Data Source CCL 4 Screening Notes

29943 27193288 Octylphenol No HE data for screening blank blank bl ank blank Production Volume >10M - 50M lbs/yr CUS/IUR Incomplete data for screening/ remains in CCL 4 Universe

20418 9036195 Octylphenol ethoxylate Lethal Dose 50 (LD50) 3500 mg/kg RTECS Toxicity Category 4 Production Volume < 500,000 lbs lbs/yr CUS/IUR Fails Screen/ remains in CCL 4 Universe

81717 66795 Oxacillin Maximum Recommended Daily Dose (MRDD) 100 mg/kg-day DSSTOX Toxicity Category 4 No Occurrence data for screening blank blank bl ank Incomplete data for screening/ remains in CCL 4 Universe

75565 61336 Penicillin Maximum Recommended Daily Dose (MRDD) 25 mg/kg-day DSSTOX Toxicity Category 4 No Occurrence data for screening blank blank bl ank Incomplete data for screening/ remains in CCL 4 Universe

6614 335671 Perfluorooctanoic acid (PFOA) Lowest Observed Adverse Effect Level (LOAEL) 0.46 mg/kg-day Lau et al., 2006 Toxicity Category 2 FW/AW 7.2 ug/L Emmett et al., 2006 (Max) Makes PCCL 4

35815 52645531 Permethrin No Observed Effect Level (NOEL) 5 mg/kg-day ITER Toxicity Category 3 Release 1,068,390 lbs/yr NCFAP Makes PCCL 4

9544 732116 Phosmet Lethal Dose 50 (LD50) 26 mg/kg RTECS Toxicity Category 2 Release 1,336,387 lbs/yr NCFAP Makes PCCL 4

2334 57830 Progesterone Acceptable Daily Intake (ADI) 0.03 mg/kg-day JECFA Toxicity Category 3 FW/AW 0.199 ug/L Kolpin et al., 2002 (Max) Fails Screen/ remains in CCL 4 Universe

2343 58220 Testosterone Acceptable Daily Intake (ADI) 0.002 mg/kg-day JECFA Toxicity Category 3 FW/AW 0.214 ug/L Kolpin et al., 2002 (Max) Fails Screen/ remains in CCL 4 Universe

2202 52686 Trichlorfon Reference Dose (RfD) 0.002 mg/kg-day OPP Toxicity Category 3 Release 861 lbs/yr TRI Fails Screen/ remains in CCL 4 Universe

4164 101202 Triclocarban No Observed Adverse Effect Level (NOAEL) 25 mg/kg-day OCSPP Toxicity Category 4 Production Volume >1M - 10M lbs/yr CUS/IUR Fails Screen/ remains in CCL 4 Universe

14798 3380345 Triclosan Lethal Dose 50 (LD50) 3700 mg/kg RTECS Toxicity Category 4 FW/AW -Median Value 0.19 ug/L NREC Fails Screen/ remains in CCL 4 Universe

A1-4EPA- OGWDW **Screening Document for the Draft PCCL 4 Nominated Contaminants**  EPA 815-R- 15-002

blank blank blank blan k bla nk Health Effect/Toxicity Data Used For CCL 4 Screening bla nk bla nk bl

a
n k Occurrence Data Used For CCL 4 Screening bl

a
n k bl

an k b blank

Substance Key CASRN Common Name Health Effect Data Element Value Units Data Source Toxicity Screening Category Occurrence Data Element Value Units Data Source CCL 4 Screening Notes

75792 1401690 Tylosin Lethal Dose 50 (LD50) 800 mg/kg RTECS Toxicity Category 4 FW/AW -Median Value 0.04 ug/L NREC Fails Screen/ remains in CCL 4 Universe

75932 11006761 Virginiamycin No HE data for screening blank blank bl ank blank No Occurrence data for screening blank blank bl ank 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 Water Works Association Research Foundation CUS/IUR - Chemical Update System/ Inventory Update Rule DSSTOX - Distributed Structure

- Searchable Toxicity Database Network Emmett et al

. , 20 06 - 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 Kolpin et al

. , 2002 - Kolpin, D.W., et al., 2002. Env. Sci. & Technol., 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 Preventi on 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. Makit a, S. Nagata et al. 1999. Environ. Toxicol. 14(1):45

- 55

A1-5