United States EPA Science Advisory Board EPA-SAB-DWC-02-006
Environmental (1400A) March 2002
Protection Agency Washington, DC ivww.epa.gov/sab
&EPA CONTAMINANT
CANDIDATE LIST
RESEARCH PLAN: AN SAB
REPORT
A REPORT BY THE DRINKING
WATER COMMITTEE OF THE
EPA SCIENCE ADVISORY BOARD
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
r WASHINGTON, D.C. 20460
OFFICE OF THE ADMINISTRATOR
SCIENCE ADVISORY BOARD
March 18, 2002
EPA-SAB-DWC-02-006
Honorable Christine Todd Whitman
Administrator
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Subject: Contaminant Candidate List Research Plan (CCLRP); An SAB Report
Dear Governor Whitman:
The Drinking Water Committee (DWC) of EPA's Science Advisory Board (SAB) met on
June 12-13, 2001 to complete its review of the Environmental Protection Agency's draft
Research Plan for the Drinking Water Contaminant Candidate List dated February 21, 2001.
The Committee first reviewed an earlier draft plan at its August 8-9, 2000 meeting and that
review resulted in an Advisory to EPA dated September 27, 2000 (EPA-SAB, 2000).
The Safe Drinking Water Act (SOWA, 1996) requires that EPA set priorities for
addressing unregulated microbiological and chemical contaminants by establishing a list of
candidate contaminants that might be regulated in the future (Contaminant Candidate List or
CCL); selecting five or more contaminants from the list to determine if they should be regulated;
and developing a regulation for those which meet the criteria for regulation. The regulatory
criteria require that the Administrator determine whether the contaminant(s): a) may cause an
adverse effect, b) are known to, or likely to, occur at levels of public health concern, and c)
regulation provides a meaningful opportunity to protect public health. The Research Plan for
the Drinking Water Contaminant Candidate List (US EPA, 2001) was developed as a plan for
identifying research to support regulatory decisions for contaminants on the first list and the
continuing identification of emerging pathogens and chemicals of potential public health
concern.
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The charge to the Drinking Water Committee asked if the two-phase decision process
described in the research plan has a high probability of providing information appropriate for the
Office of Water's regulatory determinations for CCL contaminants. Further, it asked if the
Science Advisory Board had any suggestions for improving the integrated planning of research
on unregulated contaminants.
The Committee believes that the current version of the Agency's research plan describes
a research planning process that is a substantial improvement over that reviewed by the DWC
during its August 2000 meeting. The two-phase process described in the plan is understandable
and does have a high probability of producing appropriate information for the Office of Water's
regulatory determinations on CCL contaminants. However, to be successfully implemented,
more complete operational definitions will be required for many terms, concepts and criteria that
are incorporated within the process. In particular, more explicit criteria need to be identified for
ranking and evaluating contaminants. With regard to the critical need for criteria, EPA should
begin their development by tying them to the general statutory criteria for regulatory decision
making mentioned above. Finally, it will be necessary for the Implementation Team, envisioned
in the plan, to have the authority, resources, time and administrative support needed to play its
coordinating role.
The Committee believes that one of the research plan's strengths is in its integration of
both the research decision making process with the Contaminant Candidate Listing regulatory
process that it supports. This is an improvement in research planning even though it contributes
to the complexity of the plan. Integration clearly shows that the two processes, regulatory and
research, are inextricably linked and that the criteria to be met to move forward in the regulatory
process will significantly influence the criteria for determining research needs and priorities.
Because of the link between progress in the research program and movement in the regulatory
program there is a need for a richer articulation of how the research and regulatory components
of the overall process interact. Terms used to describe the critical decision points that are built
into the processes need to be defined and criteria need to be developed for how those decisions
are made in the regulatory and research components of the overall process. The Committee
believes that developing operational definitions for these key terms, concepts and criteria will
contribute to the achievement of the objectives of the research plan.
The Committee recommends that in carrying out its CCL responsibilities, the Agency:
a) use current science research and established science policies to evaluate the basis
for its regulatory concerns, employ a transparent decision-making approach, and
make an effective use of public participation;
b) articulate the manner in which the research planning process will balance short-
term and long-term investments to maximize public health protection;
c) include a short section in the plan which clearly distinguishes between Phase I
and Phase II research, including criteria for distinguishing between the two and
several examples of each;
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d) develop explicit criteria for evaluating and ranking research on contaminants that
are being investigated under the CCL research plan; and
e) make every effort to provide the Implementation Team with the necessary time,
resources, administrative support and authority to allow them to function
effectively in their important coordination role.
We appreciate the opportunity to review and provide advice on the Agency's research
planning efforts for the Contaminant Candidate List. The EPA Science Advisory Board would
be pleased to expand on any of the findings described in this report, and we look forward to your
response.
Sincerely,
/Signed/ /Signed/
Dr. William H. Glaze, Chair Dr. R. Rhodes Trussell, Chair
EPA Science Advisory Board Drinking Water Committee
EPA Science Advisory Board
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NOTICE
This report has been written as part of the activities of the EPA Science Advisory Board,
a public advisory group providing extramural scientific information and advice to the
Administrator and other officials of the Environmental Protection Agency. The Board is
structured to provide balanced, expert assessment of scientific matters related to problems facing
the Agency. This report has not been reviewed for approval by the Agency and, hence, the
contents of this report do not necessarily represent the views and policies of the Environmental
Protection Agency, nor of other agencies in the Executive Branch of the Federal government, nor
does mention of trade names of commercial products constitute a recommendation for use.
Distribution and Availability: This EPA Science Advisory Board report is provided to the EPA
Administrator, senior Agency management, appropriate program staff, interested members of the
public, and is posted on the SAB website (www.epa.gov/sab). Information on its availability is
also provided in the SAB's monthly newsletter {Happenings at the Science Advisory Board).
Additional copies and further information are available from the SAB Staff [US EPA Science
Advisory Board (1400A), 1200 Pennsylvania Avenue, NW, Washington, DC 20460-0001; 202-
564-4533].
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US ENVIRONMENTAL PROTECTION AGENCY
EPA SCIENCE ADVISORY BOARD
DRINKING WATER COMMITTEE
CHAIR
Dr. R. Rhodes Trussell, Montgomery Watson, Pasadena, CA
Dr. Richard J. Bull, Past Chair, MoBull Consulting, Inc., Kennewick, WA
MEMBERS
Dr. David B. Baker, Retired Director, Water Quality Laboratory, Heidelberg College, Tiffin, OH
Dr. Mary Davis, Professor of Pharmacology & Toxicology, Robert C. Byrd Health Sciences Center,
West Virginia University, Morgantown, WV
Dr. Ricardo De Leon, Principal Microbiologist, Metropolitan Water District of Southern California, La
Verne, CA
Dr. Yvonne Dragan, Ohio State University, Columbus, OH
Dr. John Evans, Program in Environmental Science and Risk Management Harvard School of Public
Health, Cambridge, MA.
Dr. Sidney Green, Professor of Pharmacology, Howard University Department of Pharmacology,
Washington, DC
Dr. Barbara L. Harper, Toxicologist, Yakama Indian Nation, Richland, WA
Dr. Lee D. (L.D.) McMullen, General Manager, Des Moines Water Works, Des Moines, IA
Dr. Christine Moe, Associate Professor, Rollins School of Public Health, Emory University, Atlanta, GA
Dr. Philip Singer, Director, Drinking Water Research Center, University of North Carolina, Chapel Hill,
NC
Dr. Gary A. Toranzos, Associate Professor, Department of Biology, University of Puerto Rico, San
Juan, PR
SCIENCE ADVISORY BOARD STAFF
Mr. Thomas Miller, Designated Federal Officer, US EPA Science Advisory Board, 1200 Pennsylvania
Ave, NW, Washington, DC
Ms. Wanda Fields, Management Assistant, US EPA Science Advisory Board, 1200 Pennsylvania Ave,
NW, Washington, DC
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TABLE OF CONTENTS
1 BACKGROUND 1
1.1 Statutory Context 1
1.2 The Draft Research Plan 1
1.3 The Charge 2
1.4 The Review 3
2 CONCLUSIONS AND RECOMMENDATIONS 5
2.1 Science, Transparency, and Public Involvement 5
2.2 Near-Term Versus Long-Term Balance 7
2.3 Criteria for Regulatory determinations, regulation development, and research
prioritization 7
2.4 Health Effects Criteria 9
2.5 The Implementation Team 11
in
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1. BACKGROUND
1.1 Statutory Context
The 1996 amendments to the Safe Drinking Water Act (SDWA, 1996) require that EPA
set priorities for addressing unregulated microbiological and chemical contaminants by first
establishing a list of candidate contaminants that might be regulated in the future (Contaminant
Candidate List or CCL); selecting five or more contaminants from the list to determine if they
should be regulated; and then developing a regulation for those which meet the statutory criteria
for regulation. The first CCL was promulgated in 1998 (USEPA, 1998) and the Agency's
determination on whether or not to regulate five or more of the listed contaminants was to have
been made by August, 2001. Specific actions for each of the contaminants selected for
regulation must then follow within three and one-half years. The requirement to publish the list
of candidate contaminants, and for making regulatory determinations, is cyclical with CCL
Number 2 being required in 2003.
The criteria for regulating these contaminants are the same as that for any drinking water
contaminant. The Administrator must determine whether these contaminant(s): a) may cause an
adverse effect, or b) are known to, or likely to, occur at levels of public health concern. Further,
the Administrator must determine that regulation provides a meaningful opportunity to protect
public health. The Research Plan for the Drinking Water Contaminant Candidate List (USEPA,
2001) was developed to provide guidance on planning research to support regulatory decisions
for contaminants on the first CCL and for the continuing identification of emerging pathogens
and chemicals of potential public health concern.
1.2 The Draft Research Plan
The draft Research Plan (USEPA, 2001) addresses: a) the Agency's plan for identifying
and ranking CCL1 research needs, b) the analytical methods needed to address contaminant
occurrence/exposure/health effects/treatability, c) occurrence and exposure associated with the
contaminants in source water/finished water/distribution systems, d) the existence of significant
health risks for the contaminants, and e) the effectiveness of treatment technologies for
controlling these contaminants.
CCL1 itself lists contaminants in two categories: a) Regulatory Determination Priorities
(those having sufficient data available to evaluate exposure and risk to public health and to
support a regulatory decision), and b) Research or Occurrence Priorities (contaminants that
require additional health effects, occurrence or treatment technology data or analytical methods
development before a regulatory determination can be made). The goal of the CCL research
effort "...is to provide scientific and engineering data needed to characterize and control the risks
posed by exposure to unregulated contaminants of public health concern" (USEPA, 2001). The
research process described in the plan, proceeds in two phases and the strength and completeness
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of existing data determines whether specific contaminants fall into Phase I or Phase II of the
process.
Phase I involves screening contaminants to assign them to either the "regulatory
determination priorities category" or Phase II of the research process (i.e., the
"research/occurrence priorities category"). Phase I considers available data to decide whether
the contaminant might pose a public health hazard and if the contaminant can be treated with
current practices. Some research may be needed during Phase I to support such decisions. The
process culminates in a preliminary risk assessment/risk management analysis that decides
whether the contaminant: a) presents an imminent threat to public health, b) poses a potential
risk, or c) has an uncertain hazard potential. Imminent hazards would proceed immediately to
the Regulatory Determination track while potential or uncertain risk/hazard contaminants would
proceed to Phase II or Regulatory Determination depending on the adequacy of the existing data.
It is important to note that for CCL Number 1, the Agency has already identified a subset of
contaminants that have been determined to have sufficient data for a regulatory determination.
These contaminants are identified in the Research Plan as "Regulatory Determination Priorities."
The remaining contaminants are to go through the proposed research planning process to
determine their research needs and whether they ultimately will need to be regulated.
In Phase II the Agency will identify and prioritize research needs based on their potential
public health risk, conduct research to generate a comprehensive database, and then conclude
with a comprehensive human health risk/risk management options evaluation that informs
managers of the risk posed by a contaminant and the likely consequences of implementing
various risk management options. Phase II can then lead into the development of regulatory
proposals and promulgation of drinking water standards (or possibly other types of guidance) for
some of the contaminants.
The CCL Research Plan was developed by EPA in cooperation with a broad group of
"stakeholders." It incorporates the results of an EPA-American Water Works Association
Research Foundation (AWWARF) workshop in September 1999 (AWWARF, 1999; AWWARF,
2000). Appendices B and C to the Plan incorporate research priority recommendations resulting
from the joint EPA-AWWARF workshop and Appendix D identifies elements of a Minimal
Data Set for contaminants.
1.3 The Charge
The US EPA Science Advisory Board's Drinking Water Committee was given a charge
that asked:
a) if the two-phase decision process described in the research plan has a high
probability of providing information appropriate for the Office of Water's
regulatory determinations for CCL contaminants; and
b) if the Science Advisory Board has any suggestions for improving the integrated
planning of research on unregulated contaminants?
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The final Charge to the Drinking Water Committee was shortened from the original
charge that was the subject of the August 2000 meeting of the Committee. The charge now
focuses on the decision logic that EPA has developed to identify research to be conducted on
listed contaminants. The original charge asked for Committee advice on both the decision logic
and the research developed on CCL Number 1. The Committee did not explicitly review the
identified research, rather it focused on the decision logic itself. To the extent that the
background information on specific CCL 1 research was a factor, it was in the sense that it
provided a set of historical information to be used in evaluating that decision logic. That is, the
information can be used to evaluate the logic to see, given the type of background information
available for CCL 1, if the decision logic leads to a plan of research that will provide information
needed by EPA's Office of Water to make its CCL regulatory determinations. The Committee
response includes its conclusions, any concerns it has on a specific issue, and any suggestions for
improvements that might be made by EPA in a combined discussion.
1.4 The Review
The Drinking Water Committee (DWC) of EPA's Science Advisory Board (SAB),
convened on June 12-13, 2001 to complete the review of the Environmental Protection Agency's
draft Research Plan for the Drinking Water Contaminant Candidate List dated February 21,
2001. The Committee first reviewed an earlier draft of the plan at its August 8-9, 2000 meeting
and that review resulted in an Advisory to EPA noting their belief that it did not then have
sufficient information on the individual contaminants, and the decision process and procedures
used by EPA to decide on the research needs, to completely respond to the detailed charge
questions. The Committee provided interim advice and asked for additional information in an
Advisory dated September 27, 2000 (EPA-SAB, 2000).
The Advisory noted that:
a) the document reviewed was more a research strategy than a plan. It lacked
product and time commitments that the Committee considered to be cardinal
attributes of a research plan. Further, the plan's treatment of the roles of the
Implementation Team and others was not clear;
b) the decision processes used in phases I and II were not transparent;
c) EPA should place more emphasis on the process of research prioritization. The
Committee believed it to be clear that the research needs substantially exceeded
the resources available to the Agency for the program;
d) the need for using expert groups in developing the first plan was recognized by
the Committee and they believed that the Agency teams appeared to properly use
this approach. Nevertheless this approach is inherently not open or transparent
and the only people who really understand the decisions that are made are those
persons that participate in the exercise. To the extent possible, it is important to
attempt to formally describe, before-hand, the decision process to be used, and
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subsequently report this process, and the specifics that are obtained in applying
the method;
e) their struggle with the question of what minimal data sets are needed to make
decisions in the CCL process. They believed that the minimum data set for a
regulatory determination was likely to be considerably different from that needed
to develop a formal regulation. They recommended the development of a clear
definition of minimum data sets required for regulatory determination and for
development of full regulations;
f) caution should be used when determining whether an organism is a waterborne
pathogen. Information from epidemiologic investigations, biology and life cycle
of the organism, occurrence and survival in the aquatic environment should all be
considered, as a body of evidence, when determining the likelihood of waterborne
transmission. If an organism is associated with a waterborne disease outbreak,
then a clear concern for health effects and occurrence exists. However, absence
of information documenting waterborne disease outbreaks with a specific
pathogen does not mean that waterborne transmission of the organism is not a
concern. Also, even when outbreaks are recognized, the specific etiologic agent
is not identified in a significant portion of the outbreaks; and
g) discussions of the need for analytical methods for various microbial contaminants
should specify why the method is needed. Different analytical methods could be
used for compliance monitoring, study of microbial occurrence, or for use in
outbreak investigations.
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2. CONCLUSIONS AND RECOMMENDATIONS
The Committee considers the most recent version of the Research Plan for the Drinking
Water Contaminant Candidate List (USEPA, 2001) to be a substantial improvement over the
version reviewed during the Committee's August 2000 meeting. The Committee views the
document provided by the Agency to be more a strategy describing a decision making process
for developing a research plan than a plan itself. The two-phase process described in the
research plan is understandable and does have a high probability of producing appropriate
information for the Office of Water's regulatory determinations on CCL contaminants.
However, for this process to be successfully implemented, more complete operational definitions
will be required for many terms, concepts and criteria used throughout the plan. In particular,
more explicit criteria need to be identified for ranking contaminants. With regard to the critical
need for criteria, EPA should begin their development by tying them to the general statutory
criteria for regulatory decision making (the determination that a contaminant may have an
adverse effect on the health of persons, that it occurs with a frequency and at levels of public
health concern, and that regulation presents a meaningful opportunity for health risk reduction).
Finally it will be necessary for the Implementation Team to have the resources, time, and
administrative support needed to play its coordinating role.
2.1 Science, Transparency and Public Involvement
Recommendation Number 1: The Committee recommends that in carrying out its
CCL responsibilities, the Agency:
a) use science effectively to evaluate the basis for its regulatory concerns,
b) use a transparent decision-making approach, and
c) make effective use of public participation.
The Committee believes that the general process outlined in the CCL Research Plan is
basically sound and that one of its strengths is in its integration of the research decision making
framework with the regulatory decision making framework. However, because of this
integration, the task of evaluating and implementing the plan is much more complex. The
regulatory process for the CCL and the research process reflected in the CCL Research Plan are
clearly linked and each will have profound effects on the other. The integration reflected in the
Plan also makes it more obvious that firm decision making criteria are absent from the plan for
most of the critical decision points relevant to research directions as well as regulatory
directions. The need for clear criteria are discussed further in this report.
Concerns about the decision-making framework were discussed by the Committee during
its review meeting and the Committee is, therefore, making a number of recommendations that
address some general concerns. Though not necessarily focused on the research elements of the
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CCL process alone, the Committee felt that it was important to mention these issues because
they are critical to the success of the research (science) and regulatory (policy) processes
mentioned in the plan. These include the need for: a) transparency, b) adequate public
participation, and c) science throughout the research and regulatory process.
Each of the three elements is related to the other. It might seem that science, alone, is the
best solution. Unfortunately consensus in science requires many iterations of discussion,
research, and peer review. Its pace is deliberate and does not always respond to the time
requirements of the Agency. Regulations, on the other hand, are made in a legal climate and by
their very nature they must respond to the schedules prescribed in the law.
Within the confines of scientific consensus, most scientists will give the same answer to
questions on technical issues that are well understood (e.g., most will give the same answer
when asked to determine the speed at which a steel ball will hit the ground when it is dropped
from a height of 100 ft.). Where that consensus does not yet exist, many honest, competent
scientists will give different answers (e.g. many will give a different answer when asked if a
specific drinking water contaminant acts as a threshold carcinogen). As a result, scientific
consensus cannot be expected to answer all our regulatory questions on schedule. The CCL
Research Plan responds to the need for effective use of science in decision making by providing
a framework for identifying specific research needs to support regulatory determinations and
decisions. However, time and budget constraints may still impede the development of consensus
for each contaminant of interest according to the schedule the regulatory process must meet.
Thus, the role of decision makers becomes critical because they are charged, on behalf of
the public, with making the subjective judgements required when scientific consensus does not
exist. While the decision maker must finally make those judgements he/she must also
explain/defend the process used to make those decisions. These comments apply to decisions as
to the quality of information and its suitability for use in regulatory determinations as well as in
the regulatory determinations themselves.
This likely lack of consensus on many technical points, combined with the responsibility
for decision makers to take decisive action, leads to the need to have transparency and public
involvement. When procedures and outcomes are transparent, it is evident that a decision
process is not subject to manipulation to achieve a desired outcome.
The call for public involvement is about stakeholders having the opportunity to
participate in the decision-making dialogue and to attempt to protect their interests when they
believe that the outcome of the decision process could threaten them. Transparency makes
effective public participation possible. EPA should consider which decisions will be made in the
CCL planning process that should be open to public involvement. The Committee believes that
the decision that a contaminant is ready for regulatory determination, or that more information is
needed, is one that should be made with full public involvement.
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2.2 Near-Term Versus Long-Term Balance
Recommendation Number 2: The Committee recommends that the Agency
articulate the manner in which the decision process will balance short-term and
long-term investments to maximize public health protection.
An important planning issue that any organization must face is the natural tendency of
circumstances to favor expediency over long-term investment. It is likely that EPA research
managers will feel pressure to favor near-term investments designed to make progress in the
current regulatory cycle (before the next CCL is published) and, as a result, will be pressed to
defer some investments in long-term research. In such an environment, there is risk that long-
term research that is of great importance to public health will not be funded. There is also
another side to this same issue. First, some long-term research efforts sometimes develop fatal
flaws that only become evident once the effort has been underway for some time. Second, even
experienced research managers often need outside help in deciding when to wrap up an effort,
because their focus is necessarily on what can be done to learn more.
In finalizing the CCL Research Plan, the Committee recommends that a substantial effort
should be made to articulate how the decision process will balance short-term and long-term
investments to maximize public health protection and how projects will be reviewed to measure
the benefit of their continuation. Wherever possible objective guideposts should be provided.
2.3 Criteria for regulatory determinations, regulation development, and research
prioritization
Recommendation Number 3. Regulatory and Research Integration. The
Committee recommends that the Plan include a short section which clearly
distinguishes between Phase 1 and Phase 2 research, including criteria for
distinguishing between the two and several examples of each.
The general process outlined in the Research Plan is basically sound, however, EPA
should provide operational definitions of many terms, concepts and criteria,
mentioned in the plan or its goals may not be fully achieved (e.g., terms such as
"adequate evidence," "quality study," "uncertain risk, etc.).
The Committee believes that the general process outlined in the CCL Research Plan is
basically sound. As noted earlier, the Committee believes that a strength of the research plan is
in its integration of both the research decision making and implementation process with the
regulatory process that is envisioned for handling contaminants listed on the CCL. This is an
improvement to research planning even though it contributes to the complexity of the plan.
Integration clearly shows that the two processes, regulation and research, are inextricably linked
and that the criteria to be met to move forward in the regulatory process will significantly
influence the criteria for determining research priorities during Phase I and Phase II of the
research process.
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Because of the link between progress in the research program and movement in the
regulatory program there is a need for a richer articulation of how the research and regulatory
components of the overall process interact. There is also a need to define various terms used to
describe the critical decision points that are built into the processes and to develop criteria for
how those decisions are made. The Committee is concerned that because no operational
definitions are provided for many key terms, concepts and criteria, the plan may not fully
achieve its objectives. For example, terms such as "adequate evidence," "quality study,"
"uncertain risk," "regulatory determination", "regulatory decision" and so forth are used
throughout the document without further definition.
The current CCL research plan does not clearly describe the information necessary to
make a decision that a contaminant should be regulated and the information necessary to
construct the regulation itself. The plan appears to indicate that the information needs for both
decisions are the same. However, it seems that the time interval between regulatory
determination and actual development of the regulation can be two or more years. Therefore,
there is an implication that the information needs could be different at each of the two points in
time.
When EPA evaluates the adequacy of information for making a regulatory determination,
the outcome could be: a) to not regulate the contaminant, b) to regulate the contaminant, c) to
develop guidance (health advisories), or d) to continue to conduct research on the contaminant.
With this range of possible outcomes of regulatory determination, the goal of the CCL Research
Plan should be to provide sufficient information on occurrence, health effects and treatability to
support whatever outcome the Agency selects. Early recognition of the likely direction of the
Agency decision will be important in prioritizing the research to be conducted. Over time, EPA
should strive to have a research plan that reflects an appreciation for the different requirements
of these four outcomes and that leads the research effort through a logical progression of
information development.
Figure 2 of the Plan depicts an overview of the research and regulatory decision making
process in a simplified manner. Figures 3 and 4 depict, separately, the process included in each
of the two research program phases. Figure 4, a simplified flow diagram of Phase II of the
research program, though helpful in understanding the process in general will not be a useful
operational tool for the implementation team unless it more effectively captures some of the
complexity of the process. As a minimum, this figure would benefit from more explanatory text
on each of the process components, including details of the activities, decisions, decision criteria,
and outcomes for each element in the process depicted.
The overall decision tree should more clearly identify "on ramps" and "off ramps" that
reflect how contaminants might enter the process (other than via the CCL listing effort itself) or
might be removed from further consideration.
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2.4 Health Effects Criteria
Recommendation 4: The Committee recommends that EPA develop explicit criteria
for ranking chemical contaminants that are being investigated under the CCL
research Plan.
The objective of the CCL is to provide a "meaningful opportunity to reduce public health
risk." The Committee is not clear about how the Agency ensures that contaminants with the
greatest public health risks are placed on the list and, therefore, accorded a high priority for
research and regulatory action. Listing should involve a systematic consideration of contaminant
toxicity and occurrence/likelihood of occurrence to determine the potential for a health concern.
The Committee's suggested goal would be to have research and regulatory priorities driven by
health risk, and secondarily by costs, treatability and so on. The process should focus on real
public health threats not just those that are easiest to remove from the list or those that have
received the most attention in the news media.
The prioritization scheme discussed in the plan relies on expert judgement. The plan is
not explicit in discussing the criteria used to make judgements in planning research, therefore,
the Committee could not reconcile the results of the "test run" (from the EPA/AWWARF
workshop) with the information presented for the specific chemicals. The Committee
commented in its September, 2000, Advisory on issues and concerns with prioritization.
The Committee recognizes that in the design of any research or regulatory process there
is an inherent tension between the desire to make the process as objective and transparent as
possible and the realization that many subjective decisions are ultimately involved in the
interpretation of scientific evidence. Further, it is likely that in any sequential process the early
stages will necessarily be less formal and elaborate than the later stages.
Without objective criteria to judge the results of the research program for any
contaminant, it will be difficult to identify a stopping point for the activity. Researchers can
always uncover elements about which more useful information can be developed. In addition,
the advice of experts is an excellent way to facilitate rapid decisions of a complex nature, but,
studies have shown that the quality of the decision-making by expert groups is substantially
improved when objective criteria for decision-making are identified.
The Plan should include a table specifying the criteria for prioritization of chemical
research analogous to that included in Table 3 for Microbial Contaminants in the Plan (page 12
Feb 21, 2001 document). Flexibility should be allowed in application of the criteria. Inclusion
of these criteria will provide transparency and lessen the perception that a chemical's priority is
determined more by degree of public concern or private influence than by degree of public
health threat.
Some specific attributes of chemical agents that can result in a public health threat are
listed below. These can be used to guide the development of criteria for the prioritization or
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ranking of chemicals for listing in the CCL, for further research and characterization, and for
regulatory action.
a) occurrence of chemical in source and finished water.
b) concentration of chemical in source and finished water.
c) exceedence of the target concentration level and frequency of detection at various
degrees of exceedence.
d) potency metrics for health effects (RfD, risk level, slope factor).
e) observed concentrations or actual exposures relative to potency metrics for
various adverse health effects.
f) availability of dose response data for health endpoints: genotoxicity, cancer,
reproductive and developmental effects, neurotoxicity, endocrine,
immunotoxicity, or other target organ toxicities.
g) subpopulations likely or known to be sensitive to the chemical (by reason of age,
genetic predisposition, socioeconomic status, nutritional status, underlying
diseases, etc).
h) populations likely to be exposed (numbers of people exposed, and their
characteristics).
i) are other source contributions relevant (common exposures and relative source
contribution should be considered).
The ranking criteria could be weighted to maximize public health benefit, such that
research priorities focus on filling the data gaps for those chemicals with adverse health effects
at plausible exposures. The rationale for why specific agents were included on the current CCL
was not provided.
The implementation team is entrusted with the responsibility for determining a minimal
data set for prioritization yet the criteria to be used have not been well laid out. Since the range
of health effects is both wide and complex, this cannot be prescriptive. Still a minimal data set
could be used for provisional RfD generation on the most sensitive/important toxicity
endpoint(s). Although Appendix C contains some information on the health effects of the
chemicals, there is no established criterion for placing agents in the high, medium, or low
groupings. Furthermore, for the high priority compounds, what is known is not given.
Within the context of the research plan itself, the following criteria might be considered
for distinguishing between Phase I and Phase II research:
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a) An over-arching criterion could be time. Phase I research would be research that
could be designed, conducted and utilized in the current regulatory cycle (before
the next CCL is published). Phase II research would be research that will not be
completed and available in time to be utilized until subsequent regulatory cycles.
b) A second criterion might be that research based on study, compilation and
analysis of the literature would be classified as Phase I and research that will
require significant field or laboratory work would be classified as Phase II.
2.5 The Implementation Team
Recommendation Number 5: The Committee recommends that the EPA make
every effort to provide this team with the necessary time, resources, administrative
support and authority to allow them to function effectively in this important
coordination role.
The Implementation Team described in the revised CCL Research Plan of February 2001
plays a critical role in coordinating CCL-related research activities (both internal and extramural
research). This group is also responsible for assessing the availability of data on CCL
compounds and deciding whether the compound should be moved to regulatory determination,
Phase II research or stay in Phase I. The Implementation Team is composed of senior scientists
and managers from the Office of Water, the Office of Research and Development, the Office of
Groundwater and Drinking Water, and the Office of Science and Technology. Currently, these
individuals meet by telephone approximately every month to discuss ongoing CCL activities in
their respective Offices and consider research needs and priorities. It is apparent that the
successful implementation of the CCL Research Plan depends on effective interactions between
these representatives from different parts of EPA. The Committee recommends that the EPA
make every effort to provide this team with the necessary time, resources, administrative support
and authority to allow them to function effectively in this important coordination role.
Recommendations from the Implementation Team on funding for CCL research priorities need
to be followed by appropriate budget commitments from the fiscal administrators otherwise this
CCL Research Plan will not be viable.
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REFERENCES
AWWARF (1999). Drinking Water Research Needs Expert Workshop. Background
information for the workshop held jointly between US EPA and the American
Waterworks Association Research Foundation, September 27-29, 1999. American Water
Works Association Research Foundation, 1999.
AWWARF (2000). Research Needs Report: Report From Expert Workshop on Drinking Water
Research, Leesburg, Virginia, September 27-29, 1999. American Water Works
Association Research Foundation, 2000.
EPA Science Advisory Board (2000). An SAB Advisory on EPA 's Draft Contaminant Candidate
List Research Plan. EPA-SAB-DWC-ADV-00-007, September 27, 2000.
Safe Drinking Water Act Amendments of 1996 (1996). Public Law 104-182; August 6, 1996.
USEPA (1998) Announcement of the Drinking Water contaminant Candidate List. Federal
Register Vol. 63, No. 40, pp. 10274-10287m March 2, 1998.
USEPA (2001). Research Plan for the Drinking Water Contaminant Candidate List. US EPA
Office of Research and Development. February 21, 2001.
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