823-R-07-007
 REPORT OF THE EXPERTS SCIENTIFIC WORKSHOP ON CRITICAL
RESEARCH NEEDS FOR THE DEVELOPMENT OF NEW OR REVISED
         RECREATIONAL WATER QUALITY CRITERIA
                       DRAFT
             EXECUTIVE SUMMARY
            BY WORKGROUP CHAIRS
                       Airlie Center
                     Warrenton, Virginia
                      March 26-30, 2007
               U.S. Environmental Protection Agency
                       Office of Water
                Office of Research and Development
                       July 13, 2007

-------
U.S. Environmental Protection Agency                          Experts Scientific Workshop


                                  DISCLAIMER

This document has been reviewed in accordance with U.S. Environmental Protection Agency
(EPA) policy and approved for publication. Mention of trade names or commercial products
does not constitute endorsement or recommendation for use. Furthermore, this document is a
summary of the views of the individual workgroup chairs and approval for publication does not
signify that the contents reflect the views of the Agency and no official endorsement should be
inferred.
                             ACKNOWLEDGMENTS

EPA would  like to  thank the experts and  others who  participated in the Experts Scientific
Workshop on Critical Research Needs for the Development of New or Revised Recreational
Water Quality Criteria.  Their dedication and hard  work at and following the workshop to
produce the proceedings are greatly appreciated.  EPA would also like to thank the workgroup
chairs who worked collaboratively after the workshop to produce this Executive Summary.

Workshop Chair:
Denise Keehner, USEPA

Workshop Experts:
* Nicholas Ashbolt, USEPA
Thomas Atherholt, New Jersey Department of Environmental Protection
Michael Beach, Centers for Disease Control and Prevention
Bart Bibler, Florida Department of Health
* Alexandria Boehm, Stanford University, California
Rebecca Calderon, USEPA
Jack Colford, University of California, Berkeley
Elizabeth Doyle, USEPA
Alfred Dufour, USEPA
* Lee Dunbar, Connecticut Department of Environmental Protection
Lora Fleming, University of Miami School of Medicine and Rosenstiel School of Marine and
   Atmospheric Sciences, Florida
Donna Francy, U.S. Geological Survey
Roger Fuji oka, University of Hawaii, Manoa
Toni Glymph, Wisconsin Department of Natural Resources
Mark Gold, Heal the Bay, California
Charles Hagedorn, Virginia Tech
* Joel Hansel, USEPA
Lawrence Honeybourne, Orange County Health Care Agency, Santa Ana, California
* Paul Hunter, University of East Anglia, U.K.
* Dennis Juranek, Centers for Disease Control and Prevention (retired)
David Kay, University of Wales, U.K.
Sharon Kluender, Wisconsin State Laboratory of Hygiene
Erin Lipp, University of Georgia
July 2007

-------
U.S. Environmental Protection Agency                         Experts Scientific Workshop


Graham McBride, National Institute of Water and Atmospheric Research, New Zealand
Charles McGee, Orange County Sanitation District, California
Samuel Myoda, Delaware Department of Natural Resources
Charles Noss, USEPA
Robin Oshiro, USEPA
James Pendergast, USEPA
Mark Pfister, Lake County Health Department, Illinois
John Ravenscroft, USEPA
William Robertson, Water, Air and Climate Change Bureau, Health Canada
Stephen Schaub, USEPA
Mark Sobsey, University of North Carolina, Chapel Hill
Jeffrey Seller, Seller Environmental, California
Michael Tate, Kansas Department of Health and Environment
Peter Teunis, RIVM (National Institute of Public Health and the Environment), Netherlands
Gary Toranzos, University of Puerto Rico, Rio Piedras
Timothy Wade, USEPA
John Wathen, USEPA
* Stephen Weisberg, Southern California Coastal Water Research Project
David Whiting, Florida Department of Environmental Protection
Richard Zepp, USEPA

* Workgroup chairs and authors of this Executive Summary

Workshop Organizing Committee:
Shari Barash, USEPA
Rebecca Calderon, USEPA
Elizabeth Doyle, USEPA
Alfred Dufour, USEPA
Samantha Fontenelle, USEPA
Mark Gibson, ICF International
Patricia Harrigan, USEPA
Peggy Himes, Great Lakes Environmental Center
Rick Hoffmann, USEPA
Audrey Ichida, ICF International
Beth Leamond, USEPA
Patrick McCool, Great Lakes Environmental Center
Charles Noss, USEPA
Kevin Oshima, USEPA
John Ravenscroft, USEPA
Cynthia Roberts, USEPA
Grace Robiou, USEPA
Stephen Schaub, USEPA
Timothy Wade, USEPA
John Wathen, USEPA
July 2007                                 ii

-------
U.S. Environmental Protection Agency                           Experts Scientific Workshop


                             EXECUTIVE SUMMARY

The Experts Scientific Workshop on Critical Research and Science Needs for the Development of
New or  Revised Recreational Water  Quality  Criteria took  place  at the  Airlie Center in
Warrenton, Virginia, from March 26 to March 30, 2007.   Forty-three U.S.  and international
experts from academia, numerous states, public  interest groups, U.S. Environmental Protection
Agency (EPA or the Agency), and other federal agencies, met to discuss the state of the science
on recreational water quality research and implementation issues.

The purpose of the workshop was for EPA to obtain input from individual members of the broad
scientific and technical community on the "critical path" research and related  science needs for
developing scientifically  defensible new or  revised Clean Water Act (CWA)  Section 304(a)
recreational  ambient water quality criteria (AWQC) in the  near-term.  Near-term needs were
defined as those specific research and science activities that could be accomplished over the next
2 to 3 years  so that results would be available to EPA in time to support development of new or
revised criteria. EPA would publish the new or revised criteria in roughly 5  years (2012).

Experts were assigned to one of seven workgroups to discuss the following seven topics essential
for EPA's development of new or revised  criteria:  (1) approaches to criteria development;
(2) pathogens,  pathogen  indicators,  and  indicators   of  fecal  contamination; (3) methods
development, (4) comparing risks (to humans)  from different sources; (5) "acceptable risk";
(6) modeling applications for criteria development and implementation; and (7) implementation
realities.  The workshop proceedings dedicate a chapter to each of these seven topics.

Drafts  of the  seven  chapters of the report were written  by the experts at  the workshop.
Subsequently, the chairs of the respective groups worked with EPA to finalize each chapter and
prepare this Executive Summary.  Because  the workshop's purpose  was  to  obtain individual
input  from  each  expert,  the report is necessarily  a summary  of individual  views.   Thus,
commonalities and differences in expert opinion are acknowledged throughout the workshop
proceeding.  During their deliberations, experts were asked to consider the following four main
applications  and implementation issues associated with AWQC  for  recreational waters:   (1)
listing  of impaired waters under CWA  §303(d);  (2)  total  maximum  daily  load (TMDL)
calculations  for impaired waters; (3) National Pollutant Discharge Elimination  System  (NPDES)
permits; and (4) recreational water monitoring and notification.

Because  of the diverse nature of watersheds throughout the United States, there was  general
agreement among experts that criteria that  have  flexibility are  desirable. A common  statement
from a number of workshop participants was that a "one size fits all" criterion is inadequate for
public  health  protection and the  compliance  applications  under  the  CWA.  Workshop
participants  agreed that EPA should develop implementation guidance, including monitoring
protocols, concurrently with development of new or revised §304(a) AWQC, and that the criteria
and implementation   guidance  should be released  simultaneously.   This  would  facilitate
acceptance and adoption by States, Tribes, and Territories.

Various workshop participants suggested areas  for EPA to improve lines of communication,
including with state and local  governments and the public,  by means of clear implementation
July 2007                                  ES-1

-------
U.S. Environmental Protection Agency                           Experts Scientific Workshop


guidance and timely risk communication and education activities.  Experts also urged EPA to
communicate with other researchers who are planning to conduct relevant studies in the near
term;  importantly, researchers who plan to conduct epidemiological  studies of swimmers and
adverse health  outcomes during the summers of 2007 and 2008 to determine if any of the
methods being used are appropriate  for inclusion  in EPA's  planned summer 2007 studies.
Whether a particular method or tool (e.g., indicator type, quantification assay, use of watershed
and/or predictive models) is appropriate for addition to EPA's  planned epidemiological studies
could be judged based on whether that indicator or method is important for one or more of the
four high priority research paths discussed below.

Summary of Critical Path Research

The workshop participants  identified the following critical path research areas as high priority:
(1) human health impacts from different sources of fecal contamination; (2) measurement issues:
climatic, geographic, and temporal variability; (3) determining  risk level and subpopulations of
concern; and (4) indicators and methods for measuring fecal contamination.

Human Health Impacts from Different Sources of Fecal Contamination

There was broad support among the workshop participants for conducting research and including
in the  new or revised criteria provisions that account for differences in risks  associated with
human versus nonhuman sources of fecal contamination, and point versus non-point sources—
regardless of the framework ultimately proposed for the criteria. The absolute risk levels and the
magnitude  of differences   between animal and  human waste associated risks are not  well
characterized and may vary greatly geographically and temporally. Point sources and non-point
sources of fecal contamination also differ in risk and those  differences are not well characterized.
Workshop  participants  suggested enhancements  to epidemiological studies,  quantitative
microbial risk assessment  (QMRA), development of quantitative sanitary  investigations, and
models to aid in sanitary investigations to help characterize risks.

Epidemiological studies are the preferred approach to define and quantify human health  risks
from exposure to pathogens in recreational waters. Two principal study designs have been used
in  previous  studies of  recreational waters—randomized  control  trials and  prospective
observational cohort studies.  Epidemiological studies have historically been used to assess
human health risks at beaches impacted by point sources of fecal contamination. However, the
need for additional epidemiological studies, especially at non-point source impacted beaches, is
viewed as  essential  to  better define  risk and guide future criteria  development.  In future
epidemiological studies, consideration  should be given to enhanced study designs as well as use
of both study designs simultaneously.

QMRA can be used to rank the relative risks of different exposure scenarios, such as recreational
sites  impacted  by animal  versus human  fecal  wastes,  where  no  direct  epidemiological
information is available. QMRA can also supplement existing epidemiological data, such as has
been done in a number of specific case studies in the United States and in  other countries.
QMRA has the ability  to  consider infectivity of specific pathogens from a variety  of  fecal
sources and their fate and transport in waterbodies to estimate risk.
July 2007                                  ES-2

-------
U.S. Environmental Protection Agency                           Experts Scientific Workshop


Quantitative  sanitary investigations  for watershed characterization  could be used to classify
water quality based on relative risk,  with waters that are more likely to be impacted by human
waste being assigned a higher risk.  Some methods for watershed characterization include the
following:   methods for sanitary  investigations, methods for fecal source identification, and
modeling to determine which watershed characteristics are related to risk of illness.  Quantitative
sanitary  investigations can  address  multiple concerns  regarding the  applicability of criteria,
including the impact of different sources of fecal contamination.  The details of how quantitative
sanitary  investigations can be designed and implemented on a national  level have yet to be
determined and were not substantively addressed by the workshop participants; in part because
the process by which the details would be determined is likely to be lengthy and iterative, though
the details will be important for implementation.

                     Related Key Near-term Science and Research Needs:
         [bracketed numbers correspond to the report chapters in EPA 823-R-07-006]:
    •   Develop methods to quantify the difference in risk to human health from human
       versus animal fecal material in recreational waters.  [1, 4, 7]
       o  Conduct epidemiological  studies at locations influenced by different types
          of animals but that  are  not  influenced by treated  sewage  (wastewater)
          effluent or other human fecal sources. [2]
       o  Identify data gaps and collect data that are important for conducting QMRA
          studies for  estimating health  risks  from  different  sources  of  fecal
          contamination (e.g., humans, domesticated animals, birds,  point, non-point),
          particularly when epidemiological data are not available. [4]
       o  Conduct QMRA studies to estimate the risk of low probability/high impact
          illnesses  from  human  exposure to  animal waste in recreational waters.
          (Animals can harbor many bacterial  and protozoan pathogens that pose  a
          human  health   hazard   and   some   of   these  pathogens,  such   as
          enterohemorrhagic E. coli, can  cause serious, life-threatening  illness in
          humans.) [4, 5]
    •   Determine potential  exposure  levels  and the  associated health  risks  to
       intermittent microbial pollution discharges, combined  sewer overflows (CSOs),
       urban runoff, and concentrated animal feeding operations (CAFOs).  One aspect
       of exposure includes whether swimmers are likely to be in the water during
       these events,  and if so, collect appropriate data (e.g., for complementary QMRA
       studies).  [7]
    •   Develop protocols for using  simple, heuristic, statistical  models that correlate
       watershed activities (presence of sewage treatment plant effluents, agricultural
       activities,  domesticated animals) and attributes (slope, soil type, climate,  soil
       moisture)  to the susceptibility of a waterbody to exceed new or revised criteria
       levels. [6]
    •   Develop  quantitative rather than qualitative sanitary investigation  tools.   A
       tiered assessment of the watershed, starting with  traditional fecal  indicators
       (conservative  measures)  and progressing to select a suite  of indicators that
       provide source specificity and load information, was suggested  as one possible
       approach.  [1, 2, 7]
July 2007                                   ES-3

-------
U.S. Environmental Protection Agency                            Experts Scientific Workshop


    •  Develop indicators and associated methods for differentiating between human
       and animal  fecal contamination.  These methods could be part of a second or
       third tier of steps in evaluating a watershed, regardless of what criteria approach
       is selected.  [2, 3]

Measurement Issues: Climatic, Geographic, and Temporal Variability

There was broad support among the workshop participants for conducting research and including
in the  new or  revised criteria provisions that account for differences in climatic regions and
geographic areas.  Workshop participants were in agreement that the current state of the science
calls for the  new or revised criteria to be based on indicators of fecal contamination.  Experts
also agreed that enterococci and E.  coli are probably not  appropriate indicators in all  climatic
regions (e.g., in tropical  and subtropical climates) and geographic areas. Appropriate indicators
that correlate with recreator illness rates in tropical and subtropical climates  are needed.  New or
revised criteria need to be applicable in areas where currently accepted indicators  of fecal
contamination,  such as enterococci, may not be strongly correlated with observed excess illness
rates.  The workshop participants felt that there is no scientific rationale to support different risk
level targets  between geographic areas (i.e., freshwater and marine water)  or between  climatic
regions (tropical, subtropical, temperate).

Workshop participants agreed that the spatial and temporal variability  evident in indicator data
sets, as  well as the delay in obtaining  monitoring results using conventional culture-based
methods, rendered  the single sample standard impractical  for routine water quality notification
purposes. Simple statistical models that do not necessarily require an understanding of processes
and mechanisms have the potential to be incorporated into the new criteria, particularly for beach
monitoring and water quality notification purposes.  These  models relate water quality to
environmental  factors like wind speed, prior rainfall, and tide  level.   Models have  been
demonstrated to serve as valuable tools for making closure or advisory decisions while managers
wait for laboratory  results,  thereby  providing  for  improved public  health  protection for
swimmers as compared to relying on bacterial indicator monitoring alone. Also, once a model is
site-validated with  a sufficient baseline of monitoring, further monitoring could be reduced and
targeted to instances where the model predicts exceedences  of the  criteria.   The Modeling
workgroup members felt that due to time-lag notification errors and temporal variation known to
exist in indicator data series, day-to-day water quality notifications should not be issued using a
single  sample standard in conjunction with a microbial assay that takes longer than a few hours.

                     Related Key Near-term Science and Research Needs:
    •  Identify and develop indicators and corresponding methods that are appropriate
       for use in tropical and subtropical recreational waters. Conduct epidemiological
       studies to link those indicators with illness at tropical and subtropical locations.
       [1,2,4,5]
    •  Increase the  diversity  of  climatic  regions  and  geographic  areas where
       epidemiological  studies  are  conducted.   Also  include  different types  of
       recreational waters, such as flowing (inland) waters.  [3, 7]
July 2007                                   ES-4

-------
U.S. Environmental Protection Agency                           Experts Scientific Workshop


    •  Gain better understanding of temporal and spatial variability in environmental
       sampling  using  culture-based  and  non  culture-based  methods  and  the
       implications for their use in representing water quality.  [2, 4]
    •  Conduct research to  better  understand the human health  significance  of
       regrowth and persistence  of indicator bacteria  in  nutrient enriched surface
       waters and sand/sediments and how those impact water quality determinations.
       [5]
    •  Ensure  that  QMRA  studies conducted  for estimating health risks  from
       swimming in recreational waters include parameters and assumptions that are
       applicable for temperate, subtropical, and tropical climates.  [4, 5]
    •  Determine if data are sufficient to conduct QMRA studies for evaluating health
       risks from flowing waters and collect data if possible  and necessary.  [7]
    •  Develop, test, and validate water quality models for different water types with a
       wide range of fecal sources and locations to improve notification accuracy.  [6]

Determining Risk Level and Subpopulations of Concern

Workshop  participants felt that (1)  risks  to children should be considered as the basis for
determining risk level associated with new or revised criteria, and (2) timely risk communication
and education of the public are  critical for future acceptance of new or revised criteria.  Social
sciences research is needed to inform risk communication  strategies and to examine what the
public considers to be an "acceptable" level of risk for swimming-related illnesses. However,
the Acceptable Risk workgroup members agreed that the term "acceptable  risk" is flawed and
should be avoided during the process of developing new or revised recreational AWQC.

Workshop  participants felt that the risks to children should be better characterized and that a
better understanding of risks to children may help inform policy decisions regarding selection of
the risk level that will be associated with new or revised  criteria.  Epidemiological data indicate
that children can have a higher risk of illness than adults from swimming in fecal contaminated
recreational waters.  Two factors contributing to this difference are (1) increased exposure from
ingestion of higher volumes  of water,  and (2) greater susceptibility due  to immunological
differences compared to healthy adults.  Note, workshop participants agreed that criteria should
not  be  established based on the susceptibility of immunocompromised  individuals; rather,
targeted risk  communication  and public  health  messages  could  be  used to advise  these
individuals that they are at increased risk of illness and are advised not to swim.

Workshop   participants  emphasized that  clear  and  transparent  communication with all
stakeholders is important for the process of developing and implementing new or revised criteria.
A tiered communication plan may be an effective approach for better informing the public about
the criteria and how to interpret beach advisories and closings.  Depending on the individual's
level of interest or need, the information could be basic (e.g., a sign at a beach) or more detailed
(e.g., pamphlets, websites). Workshop participants felt that EPA has a role in assisting State and
local officials in developing risk communication strategies.
July 2007                                   ES-5

-------
U.S. Environmental Protection Agency                            Experts Scientific Workshop


                    Related Key Near-term Science and Research Needs:
    •   Review existing recreational water-related epidemiological  studies to evaluate
       risks to children. [1, 5]
    •   Include the ability to  evaluate specific risks to children when developing new
       epidemiological studies.  [1, 4, 5]
    •   Include some element  of assessing  acceptability  of risk  in  the upcoming
       epidemiological studies,  such as adding a sociological component. [5]
    •   Initiate studies to assess how impacted groups understand  and perceive risks
       associated with recreational water use and what level of voluntary risk would be
       acceptable. [5]

Indicators and Methods for Measuring Fecal Contamination

Workshop participants felt that new or revised recreational AWQC should be based on fecal
indicators.  The level of occurrence and the types of pathogens in  ambient waters vary greatly
both temporally and spatially. Some pathogens are only present in very small concentrations, yet
may present a public health risk.  Because  of these factors, methods to detect and quantify
specific pathogens in ambient waters are not sufficiently developed  at present to be practical for
use in the near-term timeframe.  Therefore, using suites of pathogens  as  the basis  for new or
revised criteria was not favored among workshop participants as a  first "line  of defense."
However, pathogen monitoring may  be useful as a subsequent tier for microbial water quality
evaluation. For longer term research needs, further development  of pathogen detection methods
may result in a more important role.

There  was broad expert support for new and/or improved methods for enumeration of fecal
contamination and specific pathogens; however, methods need to be evaluated in the context of
how they are going to be used  for specific CWA applications.  The workshop participants felt
that rapid methods are needed in some but not all water quality management situations.

Future epidemiological  study design efforts  should integrate sanitary  investigation and water
quality modeling and incorporate characterization of the source of fecal contamination, including
measurement of pathogens and  indicators.  The latter includes identifying the etiological agents
in the source of fecal  contamination  and that  cause illness in the  subjects enrolled  in the
epidemiological studies.

Many  of the enhancements  of  methods and  tools discussed throughout these proceedings are
likely to take longer than 2 to 3  years.  Therefore, the further development of these methods and
tools  should be  proactively  pursued  to facilitate  future enhancements  (beyond 2012).   In
situations where method and tool  development proceed rapidly,  then those methods and tools
would become candidates for integration into new or revised criteria in the next 5 years.

                            Related Science and Research Needs:
    •   Evaluate and validate  performance characteristics of methods that are linked to
       new or revised criteria and ensure that those methods are developed  into official
       EPA Methods. [1,2,3]
July 2007                                   ES-6

-------
U.S. Environmental Protection Agency                           Experts Scientific Workshop


    •   Develop and demonstrate the robustness of new methods for existing indicators
       (e.g., new ways of quantifying enterococci). [3]
    •   Develop  new  methods  for new indicators,  including  but not  limited  to
       Clostridium perfringens, adenoviruses, coliphages, and Bacteroides, to either
       replace or augment the current bacterial indicators.  [3, 4]
    •   Develop methods for enumeration of pathogens and indicators in wastewater.
       [1,3]
    •   Develop methods for source identification to support watershed characterization
       activities.  [3]
    •   Develop methods related to specific pathogens and fecal  source identification
       for use in a second tier of tests to provide for  a more refined assessment of risk
       of human illness.  [1,3]
    •   Conduct fate and transport studies to determine relationships between current
       and new fecal  indicators, index pathogens, and priority pathogens in treated
       effluents  and in recreational water to better  inform  the applicability  of those
       indicators and pathogens for specific CWA criteria uses.  [2, 4, 7]

Summary

EPA would like to thank the workgroup chairs and other experts for their valuable contributions
to the workshop deliberations, proceedings, and this Executive Summary, and on the state of the
science of recreational water quality  research and implementation issues.  EPA intends to use
these  reports as  it develops a critical path science plan that will help guide Agency  research
activities over the next 2 to 3 years in support of the development of new or revised recreational
AWQC.   These  research  activities  could  be  a  combination of Agency-sponsored  studies,
collaborative arrangements with external investigators and groups, or  coordination of projects
with external investigators to help supplement Agency efforts.
July 2007                                   ES-7

-------