Support for Regulatory Determination 3 Expert Reviews

Contract EP-C-08-005

Work Assignment (WA) 4-19

Meeting Summary

October 26th and 27th 2011

Washington D.C.

Prepared for:

Ali Arvanaghi – WAM

US EPA, Room 2209F

1200 Pennsylvania Ave., NW

Mail Code 4607M

Washington, DC 20460

E-mail: arvanaghi.ali@epa.gov

Prepared by:

IntelliTech Systems, Inc.

Timothy E. Soward, MPH

Technical Project Manager

tim.soward@itsysteminc.com

Hema Patel, Ph.D. 

Program Manager

hema.patel@itsysteminc.com

December 2011
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Table of Contents

1. Introduction............................................................................................................................3

2. Background............................................................................................................................3

3. Expert Review Process..........................................................................................................4

3.1 Expert Reviewers .......................................................................................................................... 4

3.2 Review Charge............................................................................................................................... 4

4. Expert Review Meeting..........................................................................................................5

4.1 Welcome and Introduction − James McFarland, IntelliTech Systems, Facilitator........................6

4.2 Background on Regulatory Determination Process...................................................................... 7

4.3 Background on Drinking Water Strategy ...................................................................................... 7

4.4 Background on Regulatory Determination 3 Process................................................................... 7

4.5 Expert Review Discussion of individual Charge Questions........................................................... 7

4.6 Regulatory Determination – Phase 1: Data Availability................................................................ 8

4.7 Regulatory Determination – Phase 2: Data Evaluation............................................................... 11

4.8 Regulatory Determination – Phase 3: Regulatory Determination Assessment..........................16

4.9 Regulatory Determination – Overall Charge Questions Comments...........................................18

4.10 Key Summary Comments from the Expert Reviewers................................................................ 19

Annex..........................................................................................................................................21
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1. Introduction

The primary goal of this Work Assignment (WA) was to provide the agency with an unbiased expert

review of the approach used for Regulatory Determination 3 (RD 3). This work consisted of a paper 

review of EPA’s October 2011 Draft Document, Protocol for the Regulatory Determination 3, by seven 

expert reviewers.1 The reviewers were chosen out of a list of over 20 potential candidates. Reviewers 

were selected based upon their availability and more importantly their experience in one or more of the 

following areas of expertise: evaluation of health and/or drinking water occurrence/exposure 

information, state drinking water or public water system perspective, and/or some familiarity with the 

RD 3 process (including the Candidate Contaminant List). A draft list of candidates was submitted to the 

EPA Work Assignment Manager (WAM) by IntelliTech Systems Inc. along with their resumes or CVs, and 

how they were identified. 

The first expert review consisted of a paper review of the Protocol for the Regulatory Determination 3

document. The reviewers were given a list of ten charge questions to which they were asked to provide 

written comments. Intellitech facilitated two teleconferences between the expert reviewers and EPA to 

provide the experts with (a) an overview of the RD 3 process and the ten charge questions, and (b) a 

forum for the experts to ask questions and make comments specific to the charge of the expert 

reviewers. After the written comments were received and compiled by IntelliTech Systems, a meeting 

was held at EPA Headquarters in Washington D.C. on October 26th and 27th of 2011 to allow the 

experts to discuss the RD 3 process and to provide EPA with constructive comments. The expert 

reviewers were able to review and edit their original written comments following the October 26th and 

27th meeting (if they chose to do so). 

2. Background

The Safe Drinking Water Act (SDWA), as amended in 1996, directed the Environmental Protection 

agency (EPA) to publish a list of contaminants referred to as the Contaminant Candidate List (CCL) to 

assist in priority-setting efforts. The SDWA also directs EPA to select five or more contaminants from the 

CCL and determine whether or not to regulate these contaminants with a National Primary Drinking 

Water Regulation (NPDWR). This process is called Regulatory Determination (RD). This work assignment 

(WA 4-19) required IntelliTech Systems Inc. to perform an expert review on the Regulatory 

Determination 3 Process Document, the Protocol for the Regulatory Determination 3.

 1 The final version of the Protocol is available in the RD 3 docket as: USEPA. 2014. Protocol for the Regulatory 

Determination 3. Including Appendices A-F. April 2014. EPA Publication # 815-R14-005.
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Expert review is intended to provide a focused, objective evaluation of a document or approach. EPA 

addresses the criticisms, suggestions, and new ideas provided by the expert reviewers prior to redrafting 

the reviewed work. Comprehensive, objective technical reviews contribute to good science and 

regulatory acceptance of precedent-setting methodologies and/or controversial issues within the 

scientific and regulated communities.

An independent expert reviewer is an expert who did not provide substantial contributions or 

consultation to the work product development. Independent expert reviewers are expected to be 

objective and free from institutional, ideological, or technical bias regarding the issues under review. 

Expert reviewers should represent a range of technically legitimate points of view (considering the 

industrial, academic, governmental, and environmental communities) that have the expertise to provide 

a balanced scientific or technical evaluation of the work.

3. Expert Review Process

3.1 Expert Reviewers

The seven reviewers selected for the RD 3 Expert Review included:

Damon Guterman, Massachusetts Department of Environmental Protection

Brian Ramaley, P.E., Newport News Waterworks

Gary Rogers Lynch, Park Water Company

Kate Sande, Minnesota Department of Health

Philip Singer, Ph.D., University of North Carolina at Chapel Hill

Mary Skopec, Ph.D., Iowa Department of Natural Resources

Lynn Thorp, Clean Water Action

3.2 Review Charge

The expert reviewers were tasked with reviewing EPA’s October 2011 Draft Document, Protocol for the 

Regulatory Determination 3. EPA prepared ten specific questions that they asked the expert reviewers

to consider in reviewing the draft document. These ten questions, which constitute the Expert 

Reviewer’s Charge, are as follows: 

1. Is the approach and evaluation described in the Regulatory Determination 3 Protocol clear, 

consistent and transparent?

2. Does the agency’s Regulatory Determination 3 Protocol sufficiently explain EPA’s interpretation and 

evaluation of the first and second SDWA statutory criteria used for making a regulatory 

determination? Note: The third statutory criterion is in the sole judgment of the Administrator.

3. Does the overall Regulatory Determination 3 process described in the Protocol identify and focus on 

contaminants of greatest public health concern to be referred to the Administrator for an evaluation 
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of the third statutory criterion (i.e., to determine whether or not regulation presents a meaningful 

opportunity for health risk reduction for persons served by public water systems)?

4. Are the data availability criteria used in Phase 1: Data Availability appropriate for identifying 

contaminants with sufficient health and occurrence data/information to be placed on the “short list” 

to proceed to Phase 2: Data Evaluation?

5. Are the information and factors considered in the Phase 2: Data Evaluation appropriate and 

sufficient for selecting contaminants of “greatest public health concern” to proceed to Phase 3: 

Regulatory Determination Assessment?

6. Are the information and factors considered in the Phase 2: Data Evaluation appropriate and 

sufficient for selecting contaminants that indicate “no to low potential for public health concern” to 

proceed to Phase 3: Regulatory Determination Assessment?

7. Does the Protocol adequately explain the rationale for those contaminants that do not proceed 

through the process (i.e., through Phases 1 and 2)?

8. In Phase 3: Regulatory Determination Assessment, has the agency used the best available science 

and integrated the data appropriately to evaluate the first and second statutory criteria for each of 

the contaminants selected for Regulatory Determination 3?

9. In the evaluation of the first and second statutory criteria for Regulatory Determination 3, did the 

agency appropriately consider the available health effects on sensitive populations?

10. Are there additional information or factors that should be considered in any of the three phases? 

Please explain why.

4. Expert Review Meeting

The Regulatory Determination 3 Expert Review Meeting convened in Washington, D.C., at the U.S. EPA 

Office of Ground Water and Drinking Water. The meeting was scheduled for the afternoon of October 

26, 2011, and a full day on October 27, 2011. 

The following sections provide a brief summary of overall comments and discussions among the RD 3 

Expert Reviewers. This summary was prepared using written notes taken during the expert review 

meeting and compiled by EPA’s contractor, IntelliTech Systems, Inc. The summary was reviewed and 

supplemented with additional written notes recorded by EPA’s OGWDW staff.
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4.1 Welcome and Introduction − James McFarland, IntelliTech Systems, 

Facilitator

The meeting began with the expert reviewers and EPA participants introducing themselves (see section 

3.1 for the list of expert reviewers). Though the expert reviewers identified their professional affiliations, 

all participants agreed that their attendance and input was based on their professional expertise and not 

as an advocate for a public water system, regulatory agency, or non-profit group. Comments were noted 

as representing the expert reviewers own personal views and professional opinions. It was also noted 

that all information discussed during the expert review was confidential EPA internal deliberative 

information. 

4.1.1 Welcoming Comments – Cynthia Dougherty, Director, USEPA Office of Ground 

Water and Drinking Water, and Pamela Barr, Director, Standards and Risk 

Management Division, USEPA OGWDW

Ms. Dougherty and Ms. Barr both expressed their thanks to the expert reviewers for participating in this 

effort and spoke of this effort as a response to the Government Accountability Office (GAO) 

recommendations for improving the consistency, clarity and transparency in the process for identifying 

drinking water contaminants that pose the greatest public health concern under the Safe Drinking Water 

Act. The expert reviewers were asked to consider during the expert review meeting and in their 

submitted written comments whether EPA’s RD 3 Protocol is logical and adequately addresses GAO’s 

concerns and whether the RD 3 Protocol (as documented) has allowed the agency to identify those 

contaminants of greatest public health concern.

When asked by the expert reviewers how OGWDW intends to use the comments and review meeting 

output, Ms. Dougherty responded that the results of the expert review discussions would be shared 

with the Deputy Administrator. 

4.1.2 Meeting Objectives and Ground Rules– Meeting Facilitator

The expert reviewers were instructed that the purpose and objective for this RD 3 Expert Review 

Meeting, was to provide a forum for:

• EPA to present and summarize its program objectives of the Protocol for the Regulatory 

Determination 3;

• Expert reviewers to discuss and clarify their written comments and exchange ideas that will help 

EPA improve the RD 3 Protocol document;

• EPA to respond to questions related to the RD 3 Protocol and help clarify the thinking that went 

into the Protocol approach; and 

• Participants to identify any available information or data that the reviewers may know of that 

could help EPA improve the document.
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EPA reinforced its objective that the meeting was intended to foster the exchange of information and 

not intended to foster debate regarding its RD 3 Protocol approach or individual expert reviewers own 

personal opinions, but rather to gather information and technical perspectives through academic 

discussion of the issues. It was stated clearly that group consensus was not sought on any of the Expert 

Review Charge questions. Moreover, the primary purpose of the meeting was to have an open 

discussion of issues and gather information that would improve the RD 3 Protocol document. 

Expert reviewers were further instructed that a written summary of the expert review meeting would be 

prepared (this document), but their submitted written comments would serve as their official comments 

in response to each charge question. The reviewers were encouraged to revise their written comments 

as they deemed necessary based on the meeting discussions. 

4.2 Background on Regulatory Determination Process

Wynne Miller, Branch Chief, Standards and Risk Reduction Branch (SRRB), Standards and Risk 

Management Division (SRMD) within OGWDW, provided a brief presentation on the background on 

Regulatory Determination and other related regulatory processes (slides included in an Annex to this 

meeting summary). 

4.3 Background on Drinking Water Strategy

Zeno Bain, RD 3 Team Leader, Standards and Risk Reduction Branch (SRRB-SRMD-OGWDW), provided a 

brief overview of EPA’s Drinking Water Strategy and how that strategy complements the RD 3 Protocol

(slides included in the Annex to this meeting summary) 

4.4 Background on Regulatory Determination 3 Process

Zeno Bain, RD 3 Team Leader, SRRB-SRMD-OGWDW, provided a brief presentation describing the 

agency’s overall approach and concept for RD 3 (slides included in the Annex to this meeting summary). 

4.5 Expert Review Discussion of individual Charge Questions

The charge questions were presented and discussed as they related to the three Phases of EPA’s RD 3

Protocol. Some of the Charge questions related to more than one of the three phases and are repeated 

below with comments limited to the phase being discussed.

Each expert reviewer was provided an opportunity to summarize their comments in answering each of 

the ten Charge questions and to ask clarifying questions of EPA staff. The summary below captures the 

highlight of the expert reviewer’s comments and EPA responses when those were sought.
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4.6 Regulatory Determination – Phase 1: Data Availability 

4.6.1 Overview of OGWDW’s Phase 1 Approach – Zeno Bain, RD 3 Team Leader, 

OGWDW

Zeno Bain presented a brief summary of Phase 1 (Data Evaluation) of the RD 3 Protocol (slides included 

in the Annex to this meeting summary).

4.6.2 Expert Review Discussion of Phase 1 Charge Questions

Charge Question 4: Are the data availability criteria used in Phase 1: Data Availability appropriate for 

identifying contaminants with sufficient health and occurrence data/information to be placed on the “short 

list” to proceed to Phase 2: Data Evaluation?

The expert reviewers acknowledged that significant effort was involved in identifying and evaluating 

occurrence and health assessment data sources. However, there appeared to be general agreement 

from the reviewers that the discussion could be clearer as to the basis for identifying and evaluating 

these data sources. The document was less clear in discussing the use of non-national occurrence data, 

than when discussing the merits of using national data. When using non-national data, the expert 

reviewers wanted examples of how they were evaluated or why the agency chose to use particular 

datasets over other datasets. 

[EPA acknowledged that the agency could increase transparency by giving examples for a selection of 

contaminants as to why they were not selected for further evaluation in Phase 2 on the basis of the 

assessment of available data sources.]

Select comments in response to this charge question include the following:

• One expert reviewer wanted greater clarity particularly on the use of non-national data and any 

judgment that was applied in selecting or deselecting these data: “Is there a minimum level of 

scientific validity that determines whether a data set is valid or not? Do not have a problem with 

the use of non-national data, but what criteria or factors are used to select the data?”

• Concern voiced about the use of some occurrence data which may lack transparency, 

inconsistent methodologies across states, and poor documentation regarding underlying values 

(e.g., raw vs. finished water errors). 

• Add a listing of the health sources to the document (similar to the occurrence sources listed in 

the appendices), explain basis for the health data assessments used (i.e., available vs. no 

assessment), and clarify if EPA and non-EPA data sources are viewed differently.

• Clarify what is meant by a peer-reviewed Health Risk Level (HRL) and whether an internal or 

external peer-review is completed.
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• Provide additional footnotes on tables in appendices (especially Appendix D of the Protocol) and 

in the document to improve the clarity of the discussion of data sources and results of each 

Regulatory Determination 3 Phase. 

• Want to be clear we are not missing contaminants of concern, such as cyanotoxins. These are 

still under study but are not moving forward to Phase 2 because occurrence data are limited. 

• Clarify the term “widely available analytical method” and what it means in the context of this 

document.

[EPA agreed to address these comments and further clarify the document.]

Charge Question 7: Does the Protocol adequately explain the rationale for those contaminants that do 

not proceed through the process (i.e., through Phases 1 and 2)?

The expert reviewers generally considered the discussion in the Protocol to be clear and logical with 

regard to the rationale for Phase 1 determinations. However, there was considerable discussion 

regarding whether the document should address what happens next to these contaminants. The 

document should further discuss how the data gaps for contaminants deemed to have insufficient data 

in Phase 1 might be addressed, including:

• Will those contaminants not proceeding to Phase 2 be placed into the Unregulated Contaminant 

Monitoring Regulation (UCMR) program? 

• Will they be placed back into the Contaminant Candidate List (CCL) if newer data becomes 

available? 

• For a lay-reader, what constitutes a data gap and “How big is a data gap before it causes an item 

to be dropped from moving forward in this process?”

• The group wanted more details on what conditions would trigger the re-examination of a 

particular contaminant by EPA. 

• What happens to “no determination” and “negative determination” contaminants?

[EPA explained that “no determination” contaminants that do not proceed to Phase 2 or 3 would be 

considered and prioritized for research to fill data gaps. For example, a contaminant that needs 

additional monitoring data could potentially be considered for inclusion on a subsequent UCMR 

monitoring cycle (pending the availability of analytical methods). EPA also explained that the CCL process 

involves an evaluation of current contaminant health and occurrence data, a screening of contaminants 

and a selection of contaminants based on an evaluation of health and occurrence attributes. 

Contaminants that have a positive or negative regulatory determination are not placed on a subsequent 

CCL unless new data indicate that the contaminant should be listed on CCL.] 

Additional comments included:
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• The grouping of contaminants caused some confusion in the discussion. 

o Why is one group in RD 3 process (nitrosamines) moving forward and another group 

(cVOCs) not?

o What happens next if during a group evaluation a particular contaminant no longer 

meets the group criteria? Does it stay in this round of Regulatory Determination or does 

it go to the next round?

[EPA explained that the evaluation of the cVOCs (carcinogenic volatile organic compounds) as the first 

group for drinking water regulation was announced in February 2011, while the RD 3 was in the midst of 

the Phase 2 evaluation. The cVOCs, which include regulated and unregulated contaminants, is a separate

but concurrent agency effort. Therefore, the contaminants included in the cVOC group do not proceed to 

Phase 3 for this RD 3 evaluation. However, the nitrosamines are being evaluated as part of this RD 3 and 

proceed to Phase 3 as a group. If particular contaminants no longer meet the group criteria, then they 

are removed from the group, but remain on the CCL and are considered for RD. The round of RD (e.g., RD

3, RD 4) that the contaminant will be considered for depends on the timing of the contaminant’s removal

from the group and its return to the CCL. The cutoff date for consideration for RD 3 is December 2011. 

However, the agency is able to make an off-cycle determination, if warranted.]

Charge Question 10: Are there additional information or factors that should be considered in any of the 

three phases? Please explain why. (Phase 1 only.)

The discussion started with one expert reviewer suggesting that the prioritization of contaminants for 

RD 3 should happen in Phase 1 and not in Phase 2. Specifically, the question was raised that if Phase 1 

has filtered out contaminants with supporting health assessment data but insufficient occurrence data, 

has EPA truly identified those contaminants posing the greatest health concern? Perhaps Phase 1 should 

seek to recommend contaminants with priority data collection needs to fill data gaps (e.g. prioritization 

to ORD for health assessments, data needs, and analytical method development).

Along those data gap lines, one expert reviewer questioned whether EPA is missing occurrences of 

contaminants, especially those with greater seasonality in occurrence that may not be found during a 

study timeframe. This reviewer noted that EPA may want to consider increased use of occurrence 

modeling to fill potential data gaps by modeling scenarios in which contaminants may be considered 

likely to occur.

[EPA agreed that although the process seeks to identify contaminants of greatest public health concern, 

it is limited by the available data. As part of the RD process and other regulatory processes, data gaps 

are identified and referred to the research team. EPA agreed that there could be seasonal variability 

among some contaminants. EPA also discussed the design of UCMR sampling and also some of the 

current uses and/or potential applicability of modeling for the drinking water program.]

Additional discussion and comments suggested EPA should acknowledge its efforts to improve both the 

CCL and RD processes. Specifically, one expert reviewer suggested that in the RD 3 Protocol Appendix A, 
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the agency may have missed an opportunity to acknowledge its support for and involvement in the 

FACA/Stakeholder process to validate and improve the NRC recommended process for identifying CCL3 

contaminants. Similarly, another expert reviewer suggested EPA needs to better explain the whole 

winnowing process to describe how it got to the RDs (i.e., from universe to PCCL to CCL to shortlist to RD 

decisions). Consider placing Appendix A in the main text of the document. Further, the agency should 

take more credit for the process it has established to identify potential drinking water contaminants 

given its resource constraints. The stakeholder process that EPA has established has led to real positive 

results and has gotten the best professional expertise available. This is best process given constraints. 

[EPA agreed to further discuss the CCL3 process as it relates to the RD 3 process and move it from the 

Protocol appendices to the main portion of the Protocol document.] 

Other comments discussed include the following:

• When discussing the minimum reporting limit (MRL), it would be beneficial to note the 

analytical method used to achieve a specific MRL (if it is known).

• The document should indicate that the potential source of contaminants was also a factor that 

was considered in selecting and evaluating contaminants. Some contaminants come from the 

treatment process itself; produced via coagulants, disinfection, etc.

• One expert reviewer suggested using 1⁄2 HRL for the non-national data to adjust for the 

uncertainty (instead of the HRL).

[EPA agreed to address these additional comments in the document.]

4.7 Regulatory Determination – Phase 2: Data Evaluation 

4.7.1 Overview of OGWDW’s Phase 2 Approach – Zeno Bain, RD 3 Team Leader, 

OGWDW

Zeno Bain discussed Phase 2 (Data Evaluation), explaining the purpose, the approach, the factors 

considered at each step, and outcome (see slides in Appendix A).

4.7.2 Expert Review Discussion of Phase 2 Charge Questions

Charge Question 5: Are the information and factors considered in the Phase 2: Data Evaluation 

appropriate and sufficient for selecting contaminants of “greatest public health concern” to proceed to 

Phase 3: Regulatory Determination Assessment?

This particular charge question generated significant discussion among the expert reviewers with regard 

to transparency in Phase 2 data evaluations. The expert reviewers noted that it appears that EPA has a 

method for prioritizing contaminants for this phase, but that the RD 3 Protocol document could be 

clearer in describing the approach used to determine whether or not the contaminants posing the 

greatest public health concern were indeed identified in Phase 2. One expert reviewer stated that this is 

probably the one area of the report that could use greater clarity in describing the methodology. The RD 
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3 Protocol Appendix E presents detailed information for each RD 3 contaminant, but it is not clear how 

all the information in Appendix E is considered in order to select the contaminants that proceed to 

Phase 3. How did EPA aggregate all the factors into a decision? The expert reviewer suggested a decision 

tree would clarify how EPA prioritizes and reaches its decisions for this phase.

[EPA agreed that a decision tree would be useful.]

After much discussion among expert reviewers of the prioritization approach presented in the RD 3 

Protocol, it was indicated that EPA is not actually developing a prioritization (i.e., ranking) of 

contaminants, but more of a binning approach to narrow down contaminants onto a list for further 

evaluation and regulatory consideration. There was broad agreement that this concept of binning 

needed to be made clearer in the document and prioritization may need to be removed from section 

titles since it gives the impression that direct contaminant comparisons were made resulting in 

individual rankings.

[EPA agreed that the process is not a prioritization/ranking of contaminants but a binning among 

contaminants with no/low occurrence, contaminants that have higher occurrence at health levels of 

concern and contaminants that have insufficient data. EPA agreed to clarify this in the document.]

The expert reviewers indicated/noted that public perception of risk is an important consideration and 

EPA should define more clearly what is meant by the “greatest public health concern” so that the public 

can better understand the agency’s goals. An expert reviewer observed that it is a challenge to make the 

method clear in the document such that the public will agree that the greatest health concerns are 

addressed and suggested EPA needed to develop an “elevator speech” for each contaminant in Phase 2 

“... as to why it rose to the level of greatest public health concern.” The RD 3 Protocol Appendix F was 

identified as a place to put such a decision summary.

[EPA indicated that the terminology used for “greatest public health concern” is meant to describe those 

contaminants occurring in public water systems at a frequency and level of concern based on available 

data. EPA indicated that they do not have a “threshold or bright line” for separating those contaminants 

with no/low occurrence from those with moderate to high occurrence.]

Another area of discussion was the process for consideration of geographically or geologically-limited 

occurrences and health risks. An expert reviewer noted that a geographically localized problem could be 

considered a “greatest public health concern” in some cases. Boron was cited as an example of a 

localized contaminant where a health advisory is issued. EPA should better explain the criteria it applies 

to geographic or geologically-limited occurrences and risks.

[EPA indicated that the agency does not have a strict definition for localized, regional or national 

occurrence, but they do evaluate the number of systems and states in which a contaminant may be 

occurring at a level and frequency of concern. EPA also noted that in those cases in which they have 

found low levels of occurrence at health levels of concern (such as boron), the agency does develop or 

updates health advisories to provide states/local agencies and water systems with health information.]
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A second expert reviewer agreed with the evaluation of geographically localized data and offered 

manganese as an example of a contaminant that ...”may have slipped through the cracks.” The reviewer 

further suggested that if there was a ranking for severity or potency (such as a high/medium/low), the 

situation with manganese may have been avoided. EPA should make its criteria more transparent about 

how severity of the health effect is considered or factored into the process. 

Other observations and comments of the expert reviewers included:

• The discussion of health effects (in the RD 3 Protocol Appendix E) could be made clearer for the 

reader using simple language.

• Concern was expressed that the HRL is the focus of the health risk determination. The 

underlying basis for the HRL should be more clearly defined. Specifically, what is EPA assuming 

about what constitutes a public health concern (cancer vs. non-cancer).

• What happens to contaminants that don’t proceed to Phase 3 (i.e., no determination 

contaminants)?

[EPA indicated that the severity of health effects was considered in the selection of contaminants for 

CCL3, but it is not a factor that is ranked or weighted in the Regulatory Determination process. All 

contaminants listed on CCL3 have been evaluated by the severity of their adverse health effects and have 

been determined to have adverse health effects by the time they reach the RD phase. The RD process 

does not evaluate the severity of the health effects but rather the three SDWA criteria: (1) May the 

contaminant have an adverse effect on the health of persons? (2) Is it known to occur or is there 

substantial likelihood that the contaminant will occur at levels and frequencies of public health concern? 

(3) In the sole judgment of the Administrator, does regulation of the contaminant present a meaningful 

opportunity to protect public health?] 

[EPA acknowledged that this section of the Protocol document could be made clearer and improve the 

document. EPA also noted that there is not a weighting or a ranking for the factors related to the health

and occurrence information.]

[Note: At this point, the meeting adjourned for the day. The discussion of Phase 2 charge questions 

resumed on Thursday morning October 27, 2011.]

Charge Question 6: Are the information and factors considered in the Phase 2: Data Evaluation 

appropriate and sufficient for selecting contaminants that indicate “no to low potential for public health 

concern” to proceed to Phase 3: Regulatory Determination Assessment?

The expert reviewers indicated that the factors considered in Phase 2 are appropriate and sufficient for 

selecting contaminants that pose no or low potential for public health concern to proceed to Phase 3, 

with the caveat that the Question 5 comments are adequately addressed by EPA. One expert reviewer 

concurred that the Phase 2 Protocol is sufficient and appropriate; however, the final Regulatory 

Determination could reverse this opinion if they are not consistent. 
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Public perception of agency actions with regard to negative determinations was also discussed, and one 

expert reviewer suggested the agency has taken unfair criticism from the public because of all the 

negative determinations in the past, but “we have determined there are not a lot of problems in the 

water supply. We have identified contaminants but determined that they are not posing problem which 

suggests intent of SDWA working.” Expert reviewers indicated that negative determinations are just as 

important as positive ones in alleviating public concern about contaminants that may/may not occur in 

their water. Other expert reviewers agreed and indicated that the agency should take credit for 

implementing a rigorous process to identify and evaluate contaminants, and that knowledgeable people 

see the negative determinations as a positive result when the public may possibly see these as a 

negative result. Additionally, providing more explanation to the general public about past negative 

determinations could be useful.

[EPA noted that in identifying and selecting contaminants that may be negative determinations, the 

agency attempts to select candidates that have the best available information since the decision to “not 

regulate” a contaminant is judicially reviewable. The agency agreed that negative determinations were 

just as important as positive determinations since it may help alleviate public concern about a particular 

contaminant.]

Additional comments and suggestions for improving the Phase 2 determinations discussion included the 

following: 

• With regard to the 11 contaminants identified in the Protocol document, identify which of these 

came through the bulleted list of criteria in the Protocol (i.e., which category or bin did they fall 

under).

• Provide greater clarity about how or what happens to contaminants designated no/low that 

may be become negative determinations, especially if new information becomes available (e.g. 

manganese). 

• State that a negative determination is important and for what reasons. 

• Occurrence data findings are summarized for particular contaminants in Appendix E of the 

Protocol. Provide the same type of summary for the health findings. 

[EPA agreed to include language about the importance of negative determinations, as well as provide an 

explanation of what happens to negative determinations and how new information might be considered. 

Additionally, EPA agreed to provide a health summary in Appendix E similar to the occurrence summary.]

Charge Question 7: Does the Protocol adequately explain the rationale for those contaminants that do not 

proceed through the process (i.e., through Phases 1 and 2)?

The discussion began with an expert reviewer comment that the document again needs to be clearer as 

to what happens to those contaminants that do not make it through the process. This was followed with 

another expert reviewer comment that EPA should further clarify that a negative determination 

contaminant goes “back to square one”, but if any new information becomes available it may return 
15

quickly to its place on the list ahead of others and “is right back on the table” for consideration. 

Therefore, the negative determination is not as final as it appears. 

It was suggested that a CCL sublist or “parking lot” of previous negative determination contaminants be 

developed so that when new information becomes available, it more easily can be brought back for CCL 

consideration. The expert reviewers seemed to like the parking lot concept.

[Note: An EPA staff person pointed out that this type of process would not have picked up manganese.]

One expert reviewer suggested that EPA include a summary under the health and occurrence 

information to further explain what the data gap is (i.e., what is the occurrence data gap or specific 

health data gap)? Are these data gaps treated equally? Provide more details on why some chemicals 

make it through the process and others do not when it appears that the data evaluation identifies 

equivocal concerns. Alachlor was cited as an example.

Another expert reviewer cited the example of dimethoate (which proceeds) and disulfoton (which does 

not proceed), presumably on the basis of national data availability. Clarify the agency’s thought process 

since disulfoton has no national data so you cannot answer yes to the Protocol question, “Does the 

contaminant have national finished water data showing no or low number or percentage of detections ≥ 

draft HRL?”. This part of the Protocol should be clearer because it is part of a decision tree and could be 

presented as such. Furthermore, why move a contaminant forward from Phase 1 to 2 with non-national 

data only, but then not allow it to proceed from Phase 2 to 3 with non-national data?

[EPA agreed to better explain why some chemicals proceed and others do not (e.g., dimethoate and 

disulfoton) and the nature of any data gap(s) or exceptions for contaminants that do not proceed. EPA

also agreed to provide an explanation of what happens to negative determinations and how new 

information might be considered.

Charge Question 10: Are there additional information or factors that should be considered in any of the 

three phases? Please explain why. (Phase 2 only.)

The expert reviewers offered few comments in response to this charge question as they felt they had 

made the relevant points already for other questions, especially those pertaining to contaminant 

prioritization. Issues and concerns that were discussed included:

• Need better information/discussion about how the HRL is developed with consideration to 

sensitive sub-populations.

• The document could better explain the concept of contaminant grouping and how 

determinations for contaminants within groups are made. For example, a positive 

determination for one or more contaminants within a group can move a group forward even if 

an individual contaminant(s) within the group is not of public health concern. In addition, 

further explain how a potential negative determination for an individual contaminant does not 

allow the group to proceed forward if other contaminants in the group have data gaps (i.e., no 

determination).
16

• The expert reviewers discussed several issues related to analytical methods. Analytical methods

need to be spelled out more clearly. Minimum Reporting Levels are an important determinant 

and need to be better discussed in the Protocol (possibly earlier in document). (Also, one expert 

reviewer noted that we need to distinguish MRLs for analytical methods from MRLs used in 

health assessments like those made by ATSDR).

• How EPA defines a method is important, especially to states for establishing lab capacity. This is 

an important point for the regulated community. Cost considerations for acquiring lab services 

are significant at public utilities, so establishing analytical methods with little capacity in the 

market, drives prices way up for utilities.

• EPA needs to think about what happens if the demand for a method drops significantly. Labs will 

not be able to perform the necessary analyses at very low volumes. 

• How much capacity must be available for a method to be considered “widely available”?

[EPA agreed to clarify a few of these items where possible, which included: how sensitive populations are 

considered, the evaluation of contaminant groups, analytical methods/MRLs used for monitoring and 

potential uncertainties/limitations, and explaining the distinction between MRL terminologies for 

analytical methods and health. Some of the other analytical methods comments may be more relevant 

to other regulatory efforts.] 

4.8 Regulatory Determination – Phase 3: Regulatory Determination Assessment

4.8.1 Overview of OGWDW’s Phase 3 Approach – Zeno Bain, RD 3 Team Leader, 

OGWDW

Zeno Bain explained the approach used for Phase 3 along with the factors considered at each step and 

the outcome (see slides in the Annex to this meeting summary).

4.8.2 Expert Review Discussion of Phase 3 Charge Questions

Charge Question 8: In Phase 3: Regulatory Determination Assessment, has the agency used the best 

available science and integrated the data appropriately to evaluate the first and second statutory criteria 

for each of the contaminants selected for Regulatory Determination 3?

The expert reviewers generally agreed that the agency had identified the best available science and 

integrated the information appropriately but could provide more transparency in the Regulatory 

Determination decision making. They noted that the RD 3 Protocol list numerous factors that are 

considered in making a regulatory determination. While the bulleted list of factors suggests a sequence 

of steps or a decision process, the expert reviewers wanted to know whether and how these factors are 

weighted. Is any one factor more important than another? Are a majority of factors needed or only one? 

What factor, if any, would tip the scale on a decision? 
17

The expert reviewers would like for the agency to define or clarify what it considers to be best available 

science, which appears to differ at times within the agency. What criteria were applied to choose a 

dataset? What is sufficient or necessary to make a decision?

As it applies to the development of the HRL, another expert reviewer agreed, stating that if using the 

best available science, then are we using the most recent studies, since it did not come through in the 

report that the science literature on health effects to create the final HRL has been updated as the 

regulatory determination is closer to being made. It is not clear that some of the health data assessment 

may be dynamic throughout the determination process and appears that it can be based on static or 

older studies. Make it clearer that the HRL is not finalized until you have completed the health support 

documents.

Additional comments included:

• The agency has diligently considered the science; however, when the preliminary regulatory 

determination is published, it is important to note that the public has opportunity to bring 

additional information to EPA’s attention.

• In the Protocol, there was some confusion over the definition and use of HRLs as benchmarks. 

Are we comparing to one benchmark carcinogen? Need to better explain the use of the 

benchmark term in the context of the HRL.

• Use and trends could be important to consider for evaluating “likely to occur.”

[EPA agreed to address these additional comments in the document.]

Charge Question 9: In the evaluation of the first and second statutory criteria for Regulatory Determination

3, did the agency appropriately consider the available health effects on sensitive populations?

The discussion began with one expert reviewer noting that they were encouraged to see that EPA has 

considered available health effects on sensitive sub-populations, particularly infants and pregnant 

women, as part of this RD 3 Protocol. Still, the document should be clearer with regard to how the data 

for these subgroups was evaluated. The RD 3 Protocol document qualitatively discusses the exposure 

risks to these sub-populations in Appendix E. Quantifying risk for sensitive sub-population, however, is 

difficult and extremely important and is included in EPA’s analysis, but it may not be apparent to a 

reader. The reviewer further indicated surprise at how important drinking water intake rates were for 

infants and pregnant women in the studies they examined and was encouraged to know that EPA 

accounts for differential drinking water intake rates for sensitive sub-populations in its analysis of health 

risk. This information should be made more obvious in the calculation of the HRL and included in 

Appendix E.

[EPA noted that strontium is an example of where age-specific drinking water intake rates are being 

applied to better characterize exposure during the period of sensitivity (i.e., bone growth). In addition, 

age-dependent adjustment factors (ADAFs) are being considered in calculating the HRL for the 

nitrosamines since they are mutagenic carcinogens. The information regarding sensitive sub-populations 
18

and HRLs will be clarified within the RD 3 Protocol and will be further explained in the RD 3 Health Effect 

Support Documents.]

Charge Question 10: Are there additional information or factors that should be considered in any of the 

three phases? Please explain why. (Phase 3 only.)

The expert reviewers had little to add in response to this question that they had not already commented 

on earlier. The points that were raised during this discussion included:

• One commenter asked if there a staff document that feeds into the Administrator’s Decision. 

[EPA noted that they brief senior managers on the information and recommendations.]

4.9 Regulatory Determination – Overall Charge Questions Comments

4.9.1 Expert Review Discussion of Overall Charge Questions

Charge Question 1: Is the approach and evaluation described in the Regulatory Determination 3 Protocol 

clear, consistent and transparent?

The expert reviewers concurred, with a few individual caveats, that the overall approach and evaluation 

described in the RD 3 Protocol was clear, consistent, and transparent. A Reviewer did add that more 

explanation is needed in those sections of the Protocol where judgment is applied to ensure 

consistency, and that transparency should carry through the entire document. Any references to 

appendix material should carry the same level of transparency supported by additional notations (e.g., 

datasets). 

Charge Question 2: Does the Regulatory Determination 3 Protocol sufficiently explain EPA’s interpretation 

and evaluation of the first and second SDWA statutory criteria used for making a regulatory determination, 

particularly criteria one and two? Note: The third statutory criterion is in the sole judgment of the

Administrator.

The expert reviewers concurred, with the same caveats and comments noted in the discussion of the 

previous questions, that the overall approach and evaluation described in the RD 3 Protocol sufficiently 

explained EPA’s interpretation and evaluation of the first and second SDWA statutory criteria for making 

regulatory determinations. Additional comments included:

• Further clarify the discussion of Low/No public health concern determination. Provide better 

understanding of which criteria tip the scale (i.e., decision tree).

Charge Question 3: Does the overall Regulatory Determination 3 process described in the Protocol identify 

and focus on contaminants of greatest public health concern to be referred to the Administrator for an 

evaluation of the third statutory criterion (i.e., to determine whether or not regulation presents a 

meaningful opportunity for health risk reduction for persons served by public water systems)?
19

The expert reviewers concurred, with the same caveats and comments noted in previous discussions, 

that the overall RD 3 process described in the Protocol (using the available knowledge and data) identified 

and focused on contaminants of greatest public health concern to be referred to the Administrator for an 

evaluation of the third statutory criterion. Additional comments included:

• Data limitations may stop a contaminant from moving forward even though it is believed to be 

of significant health concern. Cyanotoxins are a good example of this limitation.

• Be clear that the Protocol, as presented, is not an exercise in prioritization but is an exercise in 

binning or narrowing down after the highly structured prioritization scheme used in CCL3.

• Provide more discussion as to why nitrosamines move forward and CVOCs do not. Why does 

nitrobenzene fall out? 1,2,3 trichloropropane is not considered as a CVOC by some 

stakeholders/experts. 

• If specific contaminants in a group fall out of that group, how are they recaptured in the RD

process? A back-up plan is needed for these contaminants.

• Need to explain to the lay person why hot topic issues/contaminants in the news may not be on 

the list and why, as well as further clarify the agency’s definition of “greatest public health 

concern”.

[EPA agreed to clarify the following items – (a) binning versus prioritization for RD 3 and that RD 3 

follows a highly structured CCL prioritization process, (b) better explain why some groups move forward 

and others do not, (c) explain what happens if a contaminant falls out of a group, and (d) explain the use 

of the term “greatest public health concern” in the context of a regulatory determination.]

4.10 Key Summary Comments from the Expert Reviewers

The final segment of the RD 3 Expert Review Meeting involved a quick summary of the reviewer’s main 

comments on the RD 3 Protocol document. These key comments are as follows:

1. Explain better the criteria for selecting the health and occurrence data sources used in the RD 3 

Protocol. Explain how EPA identifies and evaluates these data sources. What qualified as best 

available data and which were more informative and used for corroboration? What is definition 

of best available science?

2. Explain what happens to the “no determination contaminants.” How are data gaps filled for 

those with no determinations? 

3. What happens to the potentially negative determinations? How can they be reconsidered? –

The Parking Lot concept. Explain why there may be more negative contaminants than positive 

determinations. Also explain the benefits of a negative determination and how it provides 

evidence that SDWA is working. 
20

4. Explain how contaminants are identified by binning using different criteria (e.g., data availability 

and occurrence above the threshold of public health concern). Prioritization language may need 

to be removed from document. 

5. Explain where “judgment” is used. Specifically, Phase 2 would benefit from a decision tree. 

6. Further define “greatest/threshold of public health” subject to availability of data and ability to 

proceed with regulation.

7. Explain what happens to contaminants in a group (e.g., nitrosamines or CVOCs). Why are they 

being treated in a different process? What happens to those specific contaminants that fall out 

of the group? Where and when do they enter back into the process?

8. More on CCL3 background and process discussion (move to body of document). Further explain 

the ranking/prioritization scheme used and the conclusions from those rankings in RD 3 (i.e., all 

have adverse health effects). Take more credit and demonstrate stakeholder outreach to show 

effort. List the stakeholders that were involved in the process.

9. Definition and use of HRLs as benchmarks is not entirely accurate; HRLs are normalized. Health 

risk level is not equivalent in a numeric sense in that each endpoint is not the same.

10. Better explain how sensitive sub-populations are considered in the process, both qualitatively 

and quantitatively, as it applies to derivation of the HRLs. It is included in the derivation but it is 

not described well. What are statutory drivers to consider risks to sensitive sub-populations?

The individual expert reviewer’s written comments and agency responses can be found in Response to 

External Expert Review of the Regulatory Determination 3 Protocol.
Annex

Expert Review Meeting Slideshow

October 26-27, 2011
5/1/2014

1

Regulatory Determinations 3

Expert Review Meeting

Washington D.C.

October 26-27, 2011

USEPA

Office of Ground Water and Drinking Water

Background on 

Regulatory Determinations

2
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2

SDWA Regulatory Processes

Contaminant Candidate List (CCL) – List of unregulated contaminants that are 

known or may occur in drinking water; publish every 5 years.

Regulatory Determinations – Decisions on whether to regulate CCL contaminants 

with a drinking water standard; make decisions on at least 5 every 5 years; Must 

consider 3 SDWA criteria. If decide to regulate, SDWA requires EPA to propose in 24 

months and finalize in 18 months.

Unregulated Contaminant Monitoring – Process to monitor at least 30 different 

unregulated contaminants every 5 years. 

Regulation Development - If regulate, SDWA requires that we evaluate/consider a 

number of factors in the standard setting process (health, analytical/treatment 

feasibility, costs/benefits, etc). 

Six Year Review – Every 6 years, review and (if appropriate) revise the standard. Any 

revision must maintain or improve public health protection. If revise, we go through the 

regulation development process again and evaluate a number of factors.

3

General Flow of SDWA Regulatory Processes

*For these three stages, we like to have increased specificity and confidence in the type of supporting data 

used (e.g. health and occurrence). SDWA requires that we used best available data to make our decisions.

List unregulated 

contaminants*

“Contaminant 

Candidate List”

Review & decide 

whether to revise 

the standard

“Six Year Review”

Determine whether 

at least five need a 

drinking water 

standard*

“Regulatory 

Determinations”

Develop or revise 

the drinking water 

standard*

“Regulation 

Development”

List and collect 

monitoring data at 

least 30 unregulated 

contaminants 

“Unregulated 

Contaminant 

Monitoring”

If yes

If yes

4
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3

Three Regulatory Determination Criteria

SDWA requires EPA to consider the following criteria in

evaluating whether to regulate a contaminant:

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

1) The contaminant may have an adverse effect on the 

health of persons;

3) 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.

*SDWA Section 1412(b)(1)

5

Potential Outcome of Determinations

• No Regulatory Determination

– Insufficient data to assess contaminant on three criteria

• Positive Determination

– Answer “yes” decision for “all three” criteria 

– Begin process to develop a drinking water regulation 

• Negative Determination

– Answer “no” for “any one” of the three criteria

– Do not develop a drinking water regulation

– Developing a Health Advisory is a non-regulatory option

# Outcome

1 

2 x

3 x

6
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4

2003

CCL & Regulatory Determinations Timeline

Regulatory 

Determination 1

2008

Regulatory 

Determination 2

2009

CCL3:

116 Contaminants

See Appendix A

2013

Regulatory 

Determination 3

2005

CCL2:

51 Contaminants

1998

CCL1:

60 Contaminants

9 Negative Determinations

0 Positive Determinations

11 Negative Determinations

0 Positive Determinations

Perchlorate –

Published positive 

determination 2/11

7

Background on 

Drinking Water Strategy

8
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5

Drinking Water Strategy

March 2010 Administrator Announcement

1. Address contaminants as groups rather than 

one at a time.

2. Foster development of new drinking water treatment 

technologies. 

3. Use the authority of multiple statutes to help protect 

drinking water.

4. Partner with states to share more complete data 

from monitoring at public water systems.

9

What Did We Hear From Outreach Efforts? 

• Public health protection should be of paramount importance.

• Consider the following:

– Health effect endpoints in grouping of contaminants

– Treatment feasibility to identify/address contaminant groups

– Analytical methods and/or use surrogates

– Occurrence and co-occurrence of contaminants

– Addressing groups of contaminants at their source

• Evaluate approaches used by States and other countries.

• Consider non-regulatory approaches (e.g. health advisories).

10
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6

Potential Factors & Preliminary Evaluation

• Sept 2010 DWS Stakeholder Meeting - Identified four factors to 

consider when evaluating groups: 

– Has similar health effect endpoint

– Removed by common treatment or control processes

– Measured by common analytical method(s)

– [Known or likely occurrence and co-occurrence]

• “Promising” groups likely to have multiple factors in common.

• Sept 2010 DWS Stakeholder Meeting – EPA indicated that we would 

evaluate nitrosamines as a group; addressing as part of RD3. 

• February 2011 – announced that EPA would evaluate carcinogenic 

Volatile Organic Compounds (cVOCs) as the first group for regulatory 

effort (several listed on CCL3 and mentioned in today’s discussion).

11

Overview of 

Regulatory Determinations 3

Protocol

12
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7

RegDet 3 Process Flow (Page 12)

13

Health Data Availability 

Assessment 

•Health Assessment 

available or in process

Occurrence Data 

Availability Assessment

•National data “or” 

•Non-national data with 

detects greater than CCL3 

derived HRL

Evaluation of Outcomes of Health & 

Occurrence Data Availability Assessments

Does it potentially have sufficient health 

and occurrence data available?

Phase 1: Data Availability & Evaluation

Phase 2: Data Evaluation & Prioritization

Phase 3:

Regulatory Determination Assessments

Step 1: Collect & 

Evaluate Health 

Information and Derive 

a Draft HRL

Step 2: Gather & 

Evaluate Additional 

Occurrence Data 

Sources Relative to the 

Draft HRL

Evaluate Statutory Criteria 2: 

Occurrence Assessment

Does the contaminant occur above the 

HRL at a frequency and level of public 

health concern?

Evaluate Statutory Criteria 1: 

Health Assessment

May the contaminant have an 

adverse effect on the health of 

persons?

Evaluate Statutory Criteria 3: 

Meaningful Opportunity Assessment 

(Administrator’s Decision)

In the sole judgment of the Administrator, 

does regulation of such contaminant 

present a meaningful opportunity for 

health risk reduction for persons served by 

public water systems?

CCL3 

Step 4: Identify 

Contaminants That Have 

No or Low Potential for 

Public Health Concern

Step 3: Identify 

Contaminants of Greatest 

Public Health Concern

Phase 1: Data Availability and Evaluation (Page 12)

Criteria to proceed to phase 2:

• A health assessment available 

or in process, and

• Widely available analytical 

method for monitoring available, 

and

• National finished water 

monitoring data available, or

• Non-national finished water 

monitoring data with 1 or more 

detections ≥ CCL3 HRL

• Note: Contaminants can 

proceed as part of a group 

based on factors defined by the 

Drinking Water Strategy

• Disulfoton and Diuron were 

exceptions to the criteria. The 

combination of UCMR1 

Screening Survey and 

supplementary data allowed 

these contaminants to proceed 

without “national” data.

Health Data Availability 

Assessment 

•Health Assessment 

available or in process

Occurrence Data 

Availability Assessment

•National data “or” 

•Non-national data with 

detects greater than CCL3 

derived HRL

Evaluation of Outcomes of Health & 

Occurrence Data Availability Assessments

Does it potentially have sufficient health and 

occurrence data available?

Phase 1: Data Availability & Evaluation

116 CCL3 

34 Contaminants proceed to Phase 2

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8

Health Data and Information Sources(Page 13) 

• Identify recent or in process Agency risk assessments from:

– The Agency's Integrated Risk Information System (IRIS), 

– The Agency’s Office of Water (OW), 

– The Agency's Office of Pesticide Programs (OPP), 

– The National Academy of Sciences (NAS), and/or 

– The Agency for Toxic Substances and Disease Registry (ATSDR) 

• Identify the following:

– Potential health effects

– Reference Dose (RfD) or other non-cancer health value, and/or 

– Cancer slope factor

• For phase 1, HRLs from 2009 CCL3 were used to evaluate nonnational drinking water data.

15

National Finished Water Occurrence Data Sources 

(Page 13)

• Unregulated Contaminant Monitoring Regulation (UCMR)

– UCMR 1 Assessment (2001 – 2003) 

– UCMR 2 Assessment (2008 – 2010)

• Unregulated Contaminant Monitoring (UCM)

– Round 1 (1988 – 1992)

– Round 2 (1993 – 1997)

• National Inorganics and Radionuclides Survey (NIRS) (1984 – 1986)

• Occurrence results presented as the number/percent of systems with 

an analytical result > a specified concentration (e.g., > MRL 

(detection), > 1⁄2 HRL or HRL, etc.). 

16
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9

Non-National Finished Water Occurrence 

Data Sources (Page 14)

• UCMR1 (SS)

• State Data

• DBP-ICR

• Supplemental DW data (e.g., PDP, PMP, NREC, target surveys, 

localized state/federal monitoring studies

• For phase 1, HRLs from 2009 CCL3 were used to evaluate nonnational drinking water data (1 or more detections ≥ CCL3 HRL to 

proceed)

17

See Appendix D in the RD3 

Protocol: Summary of Phase 1 

Data Availability and 

Evaluation

18
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10

Phase 1 Charge Questions

• Question 4: Are the data availability criteria used in Phase 1:

Data Availability and Evaluation appropriate for identifying 

contaminants with sufficient health and occurrence 

data/information to be placed on the “short list” to proceed to 

Phase 2: Data Evaluation and Prioritization?

• Question 7: Does the protocol adequately explain the rationale 

for those contaminants that do not proceed through the process 

(i.e., through Phases1 and 2)? 

• Question 10: Are there additional information or factors that 

should be considered in any of the three phases? Please explain 

why. (Any comments that apply to Phase 1)

19

Discussion of Phase 1 Comments

October 26 - 1:55 pm to 2:55 pm

20
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11

Phase 2: Data Evaluation & Prioritization

Step 1

Collect & Evaluate 

Health Information 

and Derive a Draft 

HRL

Step 2

Gather & Evaluate 

Additional 

Occurrence Data 

Sources Relative to 

the Draft HRL

Step 4

Identify Contaminants 

that have No or Low 

Potential Public Health 

Concern

Step 3

Identify Contaminants 

of Greatest Public 

Health Concern

Phase 2: Evaluation and Prioritization (Page 16)

11 Contaminants proceed to Phase 3

Criteria to proceed to phase 3:

• Identified as a contaminant of 

greatest public health concern

OR 

• Identified as a contaminant of 

no or low public health concern 

with sufficient data to evaluate 

the statutory criteria

21

Contaminants of Greatest Public Health Concern 

(Page 17)

• How many samples (# and %) have detections ≥ draft HRL in the 

national and non-national finished water occurrence data?

• How many systems (# and %) have detections ≥ draft HRL in the 

national and non-national finished water occurrence data?

• Is the contaminant associated with a contaminant group that is of 

public health concern and is being considered as part of the Drinking 

Water Strategy?
5/1/2014

12

Contaminants that have No or Low Potential 

for Public Health Concern (Page 18)

• Does the contaminant have national finished water data showing no or low # or % 

of detections ≥ draft HRL?

• If a contaminant has non-national finished water data, does it support no or low 

potential for occurrence in drinking water? 

• Does additional occurrence information support low or no occurrence or potential 

for occurrence in drinking water? For example, is the occurrence in 

ambient/source water at levels below the draft HRL? Are releases to the 

environment or use/production decreasing over time?

• Is there a health assessment for the contaminant that requires no or minimal 

updates and will any updates be completed by Fall 2011?

• There are no critical information/data gaps or uncertainties after evaluating the 

available health or occurrence data.

• The contaminant is not included or being evaluated with a group of contaminants 

being considered as part of the Drinking Water Strategy (e.g. cVOCs).

23

See Appendix E in the RD3 

Protocol: Summary of Phase 2 

Data Evaluation and 

Prioritization

24
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13

Phase 2 Charge Questions

• Question 5: Are the information and factors considered in the Phase 

2: Data Evaluation and Prioritization appropriate and sufficient for 

selecting contaminants of “greatest public health concern” to proceed 

to Phase 3: Regulatory Determinations Assessment?

• Question 6: Are the information and factors considered in the Phase 

2: Data Evaluation and Prioritization appropriate and sufficient for 

selecting contaminants that indicate “no to low potential for public 

health concern” to proceed to Phase 3: Regulatory Determinations 

Assessment? 

• Question 7: Does the protocol adequately explain the rationale for 

those contaminants that do not proceed through the process (i.e., 

through Phases 1 and 2)? 

• Question 10: Are there additional information or factors that should be 

considered in any of the three phases? Please explain why. (Any 

comments that apply to Phase 2)

25

26

Discussion of Phase 2 Comments

October 26 – 3:25 pm to 4:45 pm

October 27 – 9:15 am to 9:55 am
5/1/2014

14

Phase 3:

Regulatory Determination Assessments

Evaluate Statutory Criteria 2: 

Occurrence Assessment

Does the contaminant occur above 

the HRL at a frequency and level 

of public health concern?

Evaluate Statutory Criteria 1: 

Health Assessment

May the contaminant have an 

adverse effect on the health of 

persons?

Evaluate Statutory Criteria 3: 

Meaningful Opportunity Assessment 

(Administrator’s Decision)

In the sole judgment of the 

Administrator, does regulation of such 

contaminant present a meaningful 

opportunity for health risk reduction for 

persons served by public water 

systems?

• Chlorate

• Dimethoate

• 1,3- Dinitrobenzene

• N-nitrosodimethylamine (NDMA) 

• N-nitroso-di-n-propylamine (NDPA) 

• N-nitrosodiethylamine (NDEA) 

• N-nitrosopyrrolidine (NPYR)

• RDX

• Strontium

• Terbufos

• Terbufos Sulfone

27

Phase 3: Regulatory Determination 

Assessments (Page 20)

Evaluation of Statutory Criteria #1 (Page 20)

• Complete health assessment that needed to be 

updated and peer-reviewed, if necessary 

• Identify adverse health effect(s)

• Derive final peer-reviewed HRL 

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15

Factors of Primary Consideration for 

Evaluation of Statutory Criteria #2 (Page 21)

• How many samples (# and %) have detections ≥ final HRL in the national and

non-national finished water occurrence data? 

• How many systems (# and %) have detections ≥ final HRL in the national and 

non-national finished water occurrence data? 

• Is the contaminant associated with a contaminant group that is of public health

concern and is being considered as part of the DWS?

• Is the geographic distribution of contaminant occurrence national, regional or

localized? 

• In addition to the number of systems, what type of systems does the

contaminant occur in? Does the contaminant occur in large or small systems? 

Does the contaminant occur in surface or ground water systems? 

• Are there significant uncertainties or limitations with the data and/or analyses,

such as the age of the dataset, limitation of the detection limit (i.e. MRL > final

HRL) and/or representativeness of the data (e.g. limited in scope to a specific

region)? 

29

Additional Factors of Consideration for 

Evaluation of Statutory Criteria #2 (Page 21)

• How many samples (# and %) have detections ≥ 1⁄2 final HRL in the

national and non-national finished water occurrence data? 

• How many systems (# and %) have detections ≥ 1⁄2 final HRL in the

national and non-national finished water occurrence data? 

• How many samples (# and %) have detections ≥ final HRL and 1⁄2 final

HRL in the ambient/source water occurrence data? 

• How many sites (# and %) have detections ≥ final HRL and 1⁄2 final HRL in

the ambient/source water occurrence data? 

• Are production and use trends for the contaminant increasing or

decreasing? 

• How many pounds are discharged annually to surface water and/or

released to the environment? 

• Do the environmental fate and transport parameters indicate that the

contaminant would persist and/or be mobile in water? 

• Are there other uncertainties or limitations with the data and/or analyses

for these additional factors that should be considered? 

30
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16

See Appendix F in the RD3 

Protocol: Summary of Phase 3 

Regulatory Determination 3 

Assessments

31

Phase 3 Charge Questions

• Question 8: In Phase 3: Regulatory Determinations Assessment, 

has the Agency used the best available science and integrated the 

data appropriately to evaluate the first and second statutory criteria 

for each of the contaminants selected for Regulatory 

Determinations 3? 

• Question 9: In the evaluation of the first and second statutory

criteria for Regulatory Determinations 3, did the Agency 

appropriately consider the available health effects on sensitive 

populations? 

• Question 10: Are there additional information or factors that 

should be considered in any of the three phases? Please explain 

why. (Any comments that apply to Phase 3)

32
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17

33

Discussion of Phase 3 Comments

October 27 – 10:30 am to 11:30 pm

Additional Overall Charge Questions

• Question 1: Is the approach and evaluation described in the 

Regulatory Determinations 3 Protocol clear, consistent and 

transparent? 

• Question 3: Does the overall Regulatory Determinations 3 

described in the protocol identify and focus on contaminants of 

greatest public health concern to be referred to the Administrator 

for an evaluation of the third statutory criterion (i.e., to determine 

whether or not regulation presents a meaningful opportunity for 

health risk reduction for persons served by public water systems? 

• Question 2: Does the Agency’s Regulatory Determinations 3 

Protocol sufficiently explain EPA’s interpretation and evaluation of 

the first and second SDWA statutory criteria used for making 

regulatory determinations? Note: The third statutory criteria is in 

the sole judgment of the Administrator.

34
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18

35

Discussion of Overall 

Comments

October 27 – 11:30 am to 12:30 pm

Appendices

Appendix A – Contaminant Candidate List 3

Appendix B – Outreach for Addressing Contaminants as Groups

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19

Appendix A: Unregulated CCL 3 Contaminants

106 Chemicals and 12 Microbes

1,1,1,2-Tetrachloroethane 

1,1-Dichloroethane 

1,2,3-Trichloropropane 

1,3-Butadiene 

1,3-Dinitrobenzene 

1,4-Dioxane 

17 alpha-Estradiol 

1-Butanol 

2-Methoxyethanol 

2-Propen-1-ol 

3-Hydroxycarbofuran (degradate) 

4,4'-Methylenedianiline 

Acephate 

Acetaldehyde 

Acetamide 

Acetochlor 

Acetochlor ethanesulfonic acid (ESA) 

Acetochlor oxanilic acid (OA) 

Acrolein 

Alachlor ethanesulfonic acid (ESA)

Alachlor oxanilic acid (OA) 

alpha-Hexachlorocyclohexane (former) 

Aniline 

Bensulide 

Benzyl chloride 

Butylated hydroxyanisole 

Captan 

Chlorate (also D-DBP) 

Chloromethane (Methyl chloride) 

Clethodim 

Cobalt 

Cumene hydroperoxide 

Cyanotoxins (3)

Dicrotophos 

Dimethipin 

Dimethoate 

Disulfoton 

Diuron 

Equilenin

Equilin 

Erythromycin 

Estradiol (17-beta) 

Estriol 

Estrone 

Ethinyl Estradiol (17-alpha) 

Ethoprop 

Ethylene glycol 

Ethylene oxide 

Ethylene thiourea 

Fenamiphos 

Formaldehyde (formerly)

Germanium 

Halon 1011 (Bromochloromethane) 

HCFC-22 

Hexane 

Hydrazine 

Mestranol 

Methamidophos 

Methyl bromide (Bromomethane)

Methyl tert-butyl ether 

Metolachlor 

Metolachlor ethanesulfonic acid (ESA)

Metolachlor oxanilic acid (OA) 

Molinate 

Molybdenum 

Nitrobenzene 

Nitroglycerin 

N-Methyl-2-pyrrolidone 

N-Nitrosodiethylamine (NDEA) 

N-nitrosodimethylamine (NDMA) 

N-Nitroso-di-n-propylamine (NDPA) 

N-Nitrosodiphenylamine 

N-nitrosopyrrolidine (NPYR) 

Norethindrone (19-Norethisterone) 

n-Propylbenzene 

o-Toluidine 

Oxirane, methylOxydemeton-methyl 

Oxyfluorfen

Perchlorate 

Perfluorooctane sulfonic acid (PFOS)

Perfluorooctanoic acid (PFOA) 

Permethrin

Profenofos 

Quinoline 

RDX 

sec-Butylbenzene 

Strontium 

Tebuconazole 

Tebufenozide 

Tellurium 

Terbufos 

Terbufos sulfone 

Thiodicarb

Thiophanate-methyl 

Toluene diisocyanate 

Tribufos 

Triethylamine 

Triphenyltin hydroxide (TPTH) 

Urethane 

Vanadium 

Vinclozolin 

Ziram 

Adenovirus 

Caliciviruses 

Campylobacter jejuni 

Enterovirus 

Escherichia coli (0157) 

Helicobacter pylori 

Hepatitis A virus 

Legionella pneumophila 

Mycobacterium avium 

Naegleria fowleri 

Salmonella enterica 

Shigella sonnei

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Appendix B: Outreach for Addressing 

Contaminants as Groups

• Informal Planning Meeting (June 7)

• 4 Listening Sessions

 June 21 – Chicago, IL

 Aug 11 – Cincinnati, OH

 Aug 16 – Washington, DC

 Aug 19 – Rancho Cucamonga, CA

• National Drinking Water Advisory Council Consultation (July 21)

• Web Dialogue (July 28-29) and Web Forum (July 2010 to Jan 2011)

• Stakeholder Meeting (Sept 21)

• ASDWA Annual Meeting (Oct 18-21)

• National Drinking Water Advisory Council Consultation (Dec 8 & 9)

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