September 27, 2000
EPA-SAB-DWC-ADV-00-007
Honorable Carol M. Browner
Administrator
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Subject: An SAB Advisory on EPA's Draft Contaminant Candidate List (CCL)
Research Plan
Dear Ms. Browner:
The Drinking Water Committee (DWC) of EPA's Science Advisory Board (SAB) met on
August 8-9, 2000 to review the Agency's draft Contaminant Candidate List Research Plan. The
Committee appreciates the opportunity to interact with EPA as it develops this important research
program in support of EPA's implementation of this major new approach to evaluating and regulating
drinking water contaminants.
1. BACKGROUND
1.1 Statutory Context
The Safe Drinking Water Act (SDWA, 1996) requires that EPA set priorities for addressing
unregulated microbiological and chemical contaminants by first establishing a list of candidate
contaminants (Contaminant Candidate List or CCL) and then selecting five or more contaminants from
the list to determine if they should be regulated. The first such list was promulgated in 1998 (EPA,
1998) and the Agency's determination on whether or not to regulate five or more of the listed
contaminants must be 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.
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The criteria for regulating these contaminants are the same as that for any drinking water
contaminant. The Administrator must determine whether these contaminants): a) may cause an
adverse effect, b) is known or likely to occur at levels of public health concern, and c) that regulation
provides a meaningful opportunity to protect public health. The Agency must evaluate data and
information on each of these criteria in arriving at its decision on the need to develop a regulation. The
Research Plan for the Drinking Water Contaminant Candidate List (EPA/ORD, 2000) was
developed to provide guidance on research to support regulatory decisions for contaminants on the first
CCL and the continuing identification of emerging pathogens and chemicals of potential public health
concern.
1.2 The Draft Research Plan
The draft Research Plan (EPA 2000) addresses five issues: 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
data before a regulatory determination can be made). The research process described in the plan,
proceeds in two phases and the strength and completeness of existing data determines whether specific
contaminants fall into Phase I or Phase n of the process.
Phase I involves screening contaminants to assign them to either the regulatory determination
category or the research/occurrence category noted above. In Phase I a hazard identification process
is used to evaluate existing data on exposure, dose response, and occurrence, and then the availability
of analytical methods for the contaminant is considered. The intent is to determine if the contaminant
poses, or potentially poses, a hazard. If it does, then the contaminant's treatability is evaluated. For
contaminants determined in Phase I to be a hazard and which are not easily treated, Phase II then
identifies and prioritizes research needs based on their potential public health risk, conducts research to
generate a comprehensive database, and then concludes 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.
The CCL Research Plan was developed in cooperation with a broad group of "stakeholders."
It incorporates a number of other efforts including a) the results of an EPA-American Water Works
Association Research Foundation (AWWARF) workshop in September 1999, b) the results of a
special panel on risk assessment and risk characterization issues for the CCL Plan, and c) a series of
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Health Effects Data Summary sheets. 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.
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2. CHARGE
The Charge provided to the Drinking Water Committee by EPA asked the Committee:
a) if the two-phase decision process described in the research has a high probability of
providing information appropriate for the Office of Water's regulatory determinations
for CCL contaminants;
b) to evaluate the effectiveness of the plan in identifying data gaps and ranking research
needs, and whether the plan systematically identifies:
i) the needs for analytical methods?
ii) needs for occurrence, exposure, health effects and treatability research?
iii) the occurrence and exposure associated with contamination in source water, in
drinking water from natural sources and as a result of treatment processes, and
from distribution systems?
iv) the significant health risks associated with exposure to CCL contaminants?
v) The most likely treatment technologies that will control CCL contaminants?
c) if the information provided in Appendices B and C properly reflect EPA's
understanding of the issues related to health, exposure, treatment and control and if the
needs reflect the proper priority for the contaminant's potential hazard to public health,
and whether there is there additional information that EPA should consider in this
regard?
d) if the relative priorities and timetable proposed in the CCL Research Plan are adequate
for the planned research; and
e) if the Science Advisory Board has any suggestions for improving the integrated planning
of research on unregulated contaminants?
3. GENERAL CONCLUSIONS AND RECOMMENDATIONS
The Drinking Water Committee commends the Agency for its progress in developing a
research plan to addresses the regulatory program office's (Office of Water - OW) needs and the
resources available to the EPA's Office of Research and Development (ORD) in this important area.
The Committee notes the substantial progress made since it was first briefed on the information needs
to support the CCL program during Fiscal Year 1999. When complete, this plan will fill an important
need both within EPA and as a communication instrument to interested parties outside the agency.
The nature of the charge questions demonstrates that the Agency has a good grasp of the tasks
that the CCL Research Plan must address. However, it became clear to the Committee at its August,
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2000 meeting, both from the Agency's briefing and the discussions on the charge questions that ensued,
that the DWC did not have sufficient information on the individual contaminants and the process and
procedures used by EPA to arrive at their current version of the plan, to completely respond to the
charge questions. It also became clear that additional information is available and could be supplied to
the Committee. As a consequence, the Committee decided to conduct the review in two successive
interactions. The first was the August 2000 meeting, the results of which are being provided to the
Agency in this Advisory report. The second will be a meeting scheduled for January 2001 after the
Committee receives additional information and a revised version of the draft research plan. Any
revisions and supplemental details must be provided to the Committee not later than December 11,
2000 to give the members sufficient time to prepare for the January meeting.
The Agency has agreed to provide additional information to the Committee including at least: a)
the notebook of "Health Effects Data Summaries (CD format would be helpful); b) the AWWARF
workshop report - actually delivered to the DWC during the August meeting, and c) occurrence data
used in developing CCL1. The Committee suggests that the Agency consider responding to comments
made in the August meeting about the clarity and content of the current draft research plan by
developing a revised research plan. The Agency is also asked to determine whether there are other
documents that could be provided to help the Committee understand the Agency's development of the
CCL research process.
In the interim, the Committee will review the material that was provided at, and subsequent to,
the meeting. In preparing for the second meeting, the DWC will hold a telephone conference meeting
about two weeks before the meeting to evaluate where it is in terms of readiness for the January 2001
meeting.
4. SPECIFIC COMMENTS
There are seven specific points that the Committee wishes to make. These should help EPA
move to the next step in developing its CCL research plan. These are:
a) The plan is not in the form of a plan. Rather it appears to be structured as a research
strategy. It lacks the product and time commitments that are cardinal attributes of a
research plan. Designing a Research Plan to address the Candidate Contaminant List
requires the integration of a broad spectrum of technical information to develop
perspectives on what research might be done to gain the knowledge necessary to make
an informed decision on the regulation of each of the contaminants on the list. A
research plan is typically a series of proposed projects with a design rationale, a set of
priorities, and a time line and responsibility for each project. Further, in the current
draft, the role of the Implementation Team and other advisory groups is not clear. Who
is the Implementation Team accountable to? What steps are envisioned for continued
internal and external peer review of the plan? The Plan needs to be self-contained and
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include a description of the origins, the purpose, and the end results (e.g. a regulatory
determination) of the CCL in the introduction to the Plan.
b) The decision processes used in phases I and II are not transparent. It appears that the
process was primarily driven by one or more expert workshops. That is
understandable in the early development of the plan; however, there is a need for this
process to evolve, both to affirm the usefulness of the workshop approach in the near
term, and to guide the development of more formal decision processes in the future.
This document needs to clarify the processes through which CCL agents are chosen,
the mechanisms for making the decision to regulate or not, and the manner in which
regulatory determinations are made. While the process might be clarified through the
use of some explicit decision rules, because the data sets are necessarily situational,
these should be flexible. The need is for a contaminant by contaminant determination of
the key questions that must be answered to move forward on regulatory decision-
making. This will define the minimal data sets required for regulatory determination.
c) The Committee's most important advice to EPA is to place more emphasis on the
process of prioritization. The current document clearly demonstrates that the research
needs will be substantially greater than the resources available to the Agency (even
when cooperative programs elsewhere in the government and in the private sector are
considered). Consequently the CCL Research Plan must address the translation of this
knowledge into practical priorities that determine the allocation of scarce resources that
will maximize the protection of public health. This information is critical to the
document and must detail the expected public health benefits in relation to their costs.
The public health benefit must be articulated to understand how to prioritize the
development of the database necessary for regulation. The priorities should not simply
be set by a priority list of the contaminants, but must also include a clear statement of
the problem that was perceived when the contaminant was placed on the list. For each
contaminant there should be an effort to identify the critical question(s) that must be
answered to move the contaminant to the next step in the process (regulatory
determination, further research, or regulatory action). The Committee encourages the
Agency to identify those high priority research questions which may require
considerable time to resolve and recognize that in some cases smaller, but important,
gains can be made expeditiously with a lower investment of resources on a lesser
problem. The more these issues can be explicit in the planning process the better. It is
not clear how these many research needs will be prioritized and who will do this.
d) As new approaches develop, it is important to understand the process that is currently
being used. Expert workshop decisions involve both formal decision rules that can be
articulated and a considerable amount of judgment. Generally, if such a process is
necessary, it is because that judgment is a better predictor than the formal decision
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processes. The Committee recognizes the need for using groups of experts and believes
the Agency management teams properly used 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 participated in the
exercise. To the extent possible, it is important to attempt to formally describe before
hand the decision process to be used, and subsequently report this process, and the
specific judgments that were obtained in applying the method.
e) The DWC struggled with the question of what minimal data sets are necessary to make
decisions in the CCL process. The principal problem is that each contaminant is unique
and, as indicated above, the decision process is complex. As a consequence,
reviewers of the plan have to almost repeat the process in detail to determine if it
worked appropriately. As the plan was discussed in our August 2000 meeting, it
became clear that the minimum data set for a regulatory determination is considerably
different than that needed to develop a formal regulation. It is important to develop a
clear definition of the minimum data set required for regulatory determination and the
minimum data set required for the development of full regulations. Although the
Committee recommends that the Agency invest time in developing a clear definition of
these minimum data sets, it recognizes that this task will be difficult to accomplish as
each contaminant brings with it certain unique considerations. An important example is
the requirement to identify potential relationships that occur between the effects of
chronic toxicity and carcinogenicity. It is important that the minimum data-set
definitions recognize this reality. However, it would be very useful if some effort could
be made to provide an indication of what a minimum data set would be set for microbial
or chemical contaminants to support CCL decisions. Given the limitations of the
SDWA to require the development of data by the regulated community, these minimum
data sets will likely be different from those used in registration laws such as FIFRA that
have extensive data generation requirements.
f) Caution must be used when determining whether an organism is a waterborne
pathogen. As discussed on page 16 of the plan, 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. Substantial under-recognition and under-reporting of waterborne
disease outbreaks is likely. Also, even when outbreaks are recognized, the specific
etiologic agent is not identified in a significant portion of the outbreaks.
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g) The Committee agrees that 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. For example, highly sophisticated and time
consuming experimental methods may be adequate to give some indication of
occurrence; however, they would not be appropriate for compliance monitoring
purposes. For some uses, determination of viability is not always essential - especially
in source water samples; however, for outbreak investigations, illness in the population
indicates viability and infectivity. The discussion of analytical methods in the document
showed limited vision in terms of development and application of new molecular
methods. Based on information about the biology of the target organisms and similar
organisms, EPA scientists should be able to judge which methods are more likely to be
developed in the near future and which methods are more difficult to develop and will
require a longer time to develop.
The Drinking Water Committee was pleased to conduct this review of the draft research plan
and looks forward to the response of the Assistant Administrator of the Office of Research and
Development (ORD). The Committee looks forward to continuing to interact with EPA's Office of
Research and Development and Office of Water on this plan in its January 2001 meeting.
Sincerely,
/s/
Dr. Mort Lippmann, Interim Chair
Science Advisory Board
/S/
Dr. Richard J. Bull, Chair
Drinking Water Committee
Science Advisory Board
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ROSTER
U.S. Environmental Protection Agency
Science Advisory Board, Drinking Water Committee (DWC)
August 8-9, 2000 Meeting
CHAIR
DR. RICHARD BULL, MoBull Consulting, Inc., Kennewick, WA
MEMBERS
Dr. DAVID B. BAKER, Heidelberg College, Tiffin, OH
DR. MARY DAVIS, Department of Pharmacology & Toxicology, West Virginia University,
Morgantown, WV.
DR. RICARDO DE LEON, Metropolitan Water District of Southern California, Water Quality
Laboratory, La Verne, CA
DR. YVONNE DRAGAN, Ohio State University, Columbus, OH
DR. BARBARA L. HARPER, Yakama Indian Nation, Richland, WA
DR. CHRISTINE MOE, Department of Epidemiology. University of North Carolina, Chapel Hill,
NC
DR. LEE D. (L.D.) MCMULLEN, Des Moines Water Works, Des Moines, IA
DR. CHARLES O'MELIA, Department of Geography and Environmental Engineering, The Johns
Hopkins University, Baltimore, MD
DR. RHODES TRUSSELL, Montgomery Watson, Pasadena, CA
SCIENCE ADVISORY BOARD STAFF
MR. TOM MILLER, Designated Federal Official, US EPA Science Advisory Board, 1200
Pennsylvania Avenue, NW (1400A), Washington, DC
MS. DOROTHY M. CLARK, Management Assistant, US EPA Science Advisory Board, 1200
Pennsylvania Avenue, NW (1400A), Washington, DC
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NOTICE
This report has been written as part of the activities of the 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 or commercial products
constitute a recommendation for use.
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Distribution and Availability: This 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.
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REFERENCES
EPA. 1998. 63 Federal Register 10274.
EPA. 2000. Research Plan for the Drinking Water Contaminant Candidate List. US EPA, Office
of Research and Development, Draft dated August 8, 72000.
SDWA. 1996. Safe Drinking Water Act as Amended. August 6, 1996. National Drinking Water
Regulations. Code of Federal Regulations. Title XTV. Sections 1400 et seq. Congress of the
United States.
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