EPA 823-R-07-006
 REPORT OF THE EXPERTS SCIENTIFIC WORKSHOP ON CRITICAL
RESEARCH NEEDS FOR THE DEVELOPMENT OF NEW OR REVISED
          RECREATIONAL WATER QUALITY CRITERIA
                         Airlie Center
                      Warrenton, Virginia
                       March 26-30, 2007
                U.S. Environmental Protection Agency
                        Office of Water
                 Office of Research and Development
                         June 15, 2007

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                                  DISCLAIMER
This document has been reviewed in accordance with U.S. Environmental Protection Agency
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 workshop participants and approval for publication does not signify
that the contents reflect the views of the Agency and no official endorsement should be inferred.
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                             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 the workshop and following the
workshop to produce these proceedings are greatly appreciated.

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
Charles Hagedorn, Virginia Tech
Joel Hansel, USEPA
Lawrence Honeybourne, Orange County Health Care Agency, Santa Ana, California
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
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
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
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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

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
Grace Robiou              USEPA
Cynthia Roberts            USEPA
Stephen Schaub             USEPA
Timothy Wade             USEPA
John Wathen               USEPA

* Workshop proceedings document managers

Appendix B includes a complete list of all persons who attended the workshop and their
affiliations and contact information, including workshop experts, EPA resource personnel, and
meeting support personnel (note takers, meeting facilitator, logistics staff).

Report cover photo credits:
Charles Hagedorn, Virginia Tech, Blacksburg
Lawrence Honeybourne, Orange County Health Care Agency, Santa Ana, California
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                                TABLE OF CONTENTS


DISCLAIMER	i

ACKNOWLEDGMENTS	m

TABLES AND FIGURES	ix

ACRONYMS	xi

INTRODUCTION	1

1. APPROACHES TO CRITERIA DEVELOPMENT	9

  1.1 BENCHMARKS FOR CRITERIA DEVELOPMENT	11
  1.2 INTEGRATION OF WORKSHOP COMPONENTS	12
  1.3 SUMMARY OF CURRENTLY AVAILABLE WATER QUALITY CRITERIA SETTING APPROACHES	13
      1.3.1 WHO Approach for Water Quality Criteria Setting	13
      1.3.2 EU Approach for Water Quality Criteria Setting	15
      1.3.3 EPA 1986 Water Quality Criteria Setting	16
      1.3.4 Summary of Proposed Criteria Development Approaches	18
      1.3.5 Other Approaches Considered	20
  1.4 SUMMARY OF CRITICAL ISSUES TO BE RESOLVED IN APPLYING AVAILABLE WATER QUALITY CRITERIA
      APPROACHES	20
      1.4.1 Summary of Application of WHO Approach for U.S. Criteria Setting	21
      1.4.2 Summary of Application of EU Approach for U.S. Criteria Setting	23
      1.4.3 Summary of Application of EPA 1986 Approach for U.S. Criteria Setting	23
  1.5 SUMMARY OF RESPONSE TO WORKGROUP CHARGE QUESTIONS	24
  1.6 CONCLUDING REMARKS	33

2. PATHOGENS, PATHOGEN INDICATORS, AND INDICATORS OF FECAL CONTAMINATION	35

  2.1 APPLICATION OF MICROBIAL/BIOMARKER PARAMETERS	37
  2.2 TIERED TOOLBOX MONITORING APPROACH	38
  2.3 PARAMETERS FOR HAZARDOUS EVENT POLLUTION MONITORING	39
      2.3.1 Microbiological Parameters	39
  2.4 TRADITIONAL FECAL INDICATORS (COLIFORMS & ENTEROCOCCI)	40
  2.5 ALTERNATIVE FECAL INDICATORS	41
      2.5.1 Bacteria	41
      2.5.2 Bacteriophages	43
      2.5.3 EU Project Summary of Tracers	46
  2.6 PATHOGENS AND PATHOGEN INDICATORS	47
  2.7 CHEMICAL BIOMARKERS OF FECAL CONTAMINATION	49
      2.7.1 Fecal Sterols	49
      2.7.2 Caffeine	49
      2.7.3 Optical Brighteners and Other Sewage Markers	50
  2.8 RESEARCH NEEDS	51
      2.8.1 Withina  1 to 3 Year Timeframe	51
      2.8.2 Longer-term Research Goals	52

3. METHODS DEVELOPMENT	57

  3.1 INTRODUCTION	59
  3.2 CLASSES OF INDICATORS	60
  3.3 EVALUATING NEW METHODS FOR EXISTING INDICATORS	62
      3.3.1 Health Risk Evaluation	62
      3.3.2 Establishing Equivalency between New and Standard Methods	63
  3.4 PERFORMANCE CRITERIA	63
  3.5 EVALUATION PROCESS FOR ALTERNATIVE (NEW) INDICATORS	66
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   3.6 EVALUATING SOURCE IDENTIFICATION METHODS - PROFICIENCY AND EVALUATION	67
       3.6.1  Library-independent Methods	67
       3.6.2  Non-microbial Methods	68
       3.6.3  Library-Based Methods	68
   3.7 MODIFICATIONS TO THE EVALUATION PROCESS WHEN INDICATORS ARE USED FOR OTHER APPLICATIONS ....68
   3.8 RESEARCH NEEDS	69

4.  COMPARING RISK (TO HUMANS) FROM DIFFERENT SOURCES	75

   4.1 INTRODUCTION	77
   4.2 SUMMARY OF WORKGROUP DISCUSSIONS AND REFLECTIONS ON WORKGROUP-SPECIFIC CHARGE AND
       QUESTIONS	80
   4.3 OPTIONS FOR APPROACHES AND IMPLEMENTATION CONSIDERATIONS	82
   4.4 RESEARCH NEEDS	83
       4.4.1  Epidemiological Studies	83
       4.4.2  Quantitative Microbial Risk Assessment	85
       4.4.3  Etiologic Agents	86
       4.4.4  Fate and Transport	87
       4.4.5  Determine the Occurrence of Pathogens in Affected Recreational Waters	88
       4.4.6  Bather Studies	89
       4.4.7  Additional Research	89

5.  ACCEPTABLE RISK	91

   5.1 INTRODUCTION	93
   5.2 MAIN CONCLUSIONS AND OBSERVATIONS	93
       5.2.1  Whether the Term 'Acceptable Risk' is Still the Most Appropriate Term	93
       5.2.2  Public Involvement in 'Acceptable Risk' Decisions	94
       5.2.3  'Acceptable Risk' Levels for the General Population	95
       5.2.4  'Acceptable Risk' Levels for Vulnerable Subgroups	97
       5.2.5  What are the Current Levels of Protection from Existing Criteria?	99
       5.2.6  Potential Synergies for Health Protection between Revised Recreational Water Criteria and
            Standards for Drinking Water Sources and Shellfish Harvesting Waters	100
       5.2.7  Areas of Discord	100
   5.3 RESEARCH NEEDS	100

6.  MODELING APPLICATIONS FOR CRITERIA DEVELOPMENT AND IMPLEMENTATION	105

   6.1 INTRODUCTION	107
       6.1.1  Water Quality Notification	107
       6.1.2 Sanitary Investigation Models	109
   6.2 How MODELS ARE CURRENTLY BEING USED	110
       6.2.1 Sanitary Investigation Models	110
       6.2.2  Water Quality Notification Models	Ill
       6.2.1  Communication of Modeled Information to the Public and Recreational Water Managers	113
   6.3 ADVANTAGES AND DISADVANTAGES OF MODELING	114
       6.3.1  Advantages of Modeling	114
       6.3.2  Disadvantages of Modeling	115
   6.4 MODEL DEVELOPMENT AND EVALUATION	117
       6.4.1  Initiating Model Development for Water Quality Notification	117
       6.4.2  Model Development for Water Quality Notification	117
       6.4.3  Data Needs for Simple Sanitary Investigation Model Development	119
       6.4.4  Cost Estimates	119
       6.4.5  Understanding the Uncertainty and Measuring Success of Statistical Models	119
   6.5 RESEARCH NEEDS	120
       6.5.1  Short-term Research Needs (2 to 3 years)	121
       6.5.2  Longer-term Research Needs (8 to 10 years)	123

7.  IMPLEMENTATION REALITIES	129
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  7.1 APPLICATION TO SPECIFIC PROGRAM AREAS	131
      7.1.1 Beach Monitoring and Water Quality Notification Programs	131
      7.1.2 NPDES Permitting Programs	135
      7.1.3 Monitoring and Assessment for CWA §303(d) and §305(b)	136
      7.1.4 Total Maximum Daily Load Program	139
      7.1.5 Important Differences Between Workgroup Members as to Views/Observations	140
  7.2 EVALUATION OF ALTERNATIVE APPROACHES FOR CRITERIA DEVELOPMENT	140
      7.2.1 WHO Approach	141
      7.2.2 EU Approach	143
      7.2.3 Existing U.S. Model-1986 Criteria	144
      7.2.4 Alternative Approaches	145
  7.3 RESEARCH NEEDS	145
      7.3.1 Near-term (Next 1 to 3 Years)	146
      7.3.2 Long-term (Beyond 3 Years)	147

APPENDIX A: CHARGE TO THE EXPERT WORKGROUP MEMBERS	A-l

APPENDIX B: PARTICIPANT LIST	B-l

APPENDIX C: TRANSLATION OF EPIDEMIOLOGY TO DISEASE BURDEN BY WHO AND EU	c-1

APPENDIX D: SUMMARY OF THE EUROPEAN COMMISSION DIRECTIVE	o-l

APPENDIX E: INDICATOR TERMINOLOGY	E-l

APPENDIX F: SUMMARY OF MEASUREMENTS CURRENTLY PLANNED FOR THE DOHENY AND MALIBU
            BEACH (CALIFORNIA) EPIDEMIOLOGY STUDY	F-l

APPENDIX G: DEVELOPMENT OF DETERMINISTIC MODELS	c-1
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                              TABLES AND FIGURES

TABLE 1.       WHO CLAS SIFICATION MATRIX FOR INTEGRATING MICROBIAL WATER QUALITY AS
             MEASURED BY ENTEROCOCCI DENSITY WITH SANITARY INSPECTION CATEGORY	14
TABLE 2.       NUMERICAL MICROBIOLOGICAL WATER QUALITY ASSESSMENT CLASSIFICATION FOR FRESH
             (INLAND) AND MARINE (COASTAL AND TRANSITIONAL) BATHING WATERS FOR THE 24 EU
             MEMBER STATES	16
TABLE 3.       SUMMARY OF EPA's 1986 RECOMMENDED WATER QUALITY CRITERIA FOR BACTERIA AND
             2004 RULE	17
TABLE 4A.     SUMMARY OF PROPOSED CRITERIA DEVELOPMENT APPROACHES :  STRENGTHS AND
             LIMITATIONS	18
TABLE 4s.     SUMMARY OF THREE PROPOSED CRITERIA DEVELOPMENT APPROACHES : BENCHMARKS	19
TABLES.       COMPARING RISKS (TO HUMANS) FROM DIFFERENT PATHOGEN SOURCES	78
TABLE 6.       RESEARCH NEEDS AND RANKINGS FROM FIVE "ACCEPTABLE RISK" WORKGROUP MEMBERS	103
TABLE E-1.     DEFINITIONS FOR INDICATOR AND INDEX MICROORGANISMS OF PUBLIC HEALTH CONCERN	E-1
TABLE F-1.     SUMMARY OF MEASUREMENTS CURRENTLY PLANNED FOR THE DOHENY AND MALIBU
             BEACH (CALIFORNIA) EPIDEMIOLOGY STUDY	F-l

TEXT Box E-l.  DEFINITIONS OF KEY FECAL INDICATOR MICROORGANISMS	E-l

FIGURE 1.      FLOW DIAGRAM OF How THE WORKGROUP COMPONENTS CONTRIBUTE TO THE
             DEVELOPMENT OF NEW OR REVISED RECREATIONAL WATER QUALITY CRITERIA	3
FIGURE 2.      CLEAN WATER ACT: WATER QUALITY STANDARDS OVERVIEW	5
FIGURE 3.      FLOW DIAGRAM OF How THE WORKGROUP TOPICS CONTRIBUTE TO THE DEVELOPMENT AND
             IMPLEMENTATION OF NEW OR REVISED RECREATIONAL WATER QUALITY CRITERIA	13
FIGURE 4A.     ENTEROCOCCI (MPN/100 ML) SAMPLED EVERY 10 MINUTES AT A BEACH IN CALIFORNIA	108
FIGURE 4B.     SUBTROPICAL MARINE BEACH (MIAMI, FLORIDA): 48 HOURS SAMPLING	108
FIGURE 5.      THE POSSIBLE FATES OF MICROBES (FECAL INDICATORS AND PATHOGENS) IN
             ENVIRONMENTAL WATER AND SEDIMENT	124
FIGURE C-1.    A PROBABILITY DENSITY FUNCTION OF FECAL INDICATOR DISTRIBUTIONS MEASURED AT A
             RECREATIONAL WATER SHOWING PROBABILITY OF EXPOSURE (Y Axis) VERSUS LoolO
             FECAL STREPTOCOCCI CONCENTRATION	C-2
FIGURE C-2.    THE DOSE-RESPONSE RELATIONSHIP DERIVED FROM KAY ET AL. (1994) (A) AND THE
             FUNCTIONAL FORM USED TO DERIVE THE 2003 WHO GUIDELINE VALUES (B)	C-2
FIGURE C-3.    COMBINING THE DOSE-RESPONSE CURVE AND THE PDF TO PRODUCE A RELATIVE DISEASE
             BURDEN ASSESSMENT FOR ANY BEACH OR REGION	C-3
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7Q10

AWQC
ASABE
ATP
BEACH Act
BMP
CAFO
CDC
cfu
cso
CWA
DNA
DU
EHEC
EPA
EU
FDA
FFU
GC/MS
GI
GIS
GM
HACCP
HEV
HIV/AIDS
HPLC
HSPF
ILSI
IMS
ISO
L
mL
MPN
MST
NASBA
NEEAR

NOAA
NPDES
NPS
NWS
PCR
pfu
               ACRONYMS

the lowest streamflow for 7 consecutive days that occurs on average once
every 10 years
ambient water quality criteria
American Society of Agricultural and Biological Engineers
adenosine triphosphate
Beaches Environmental Assessment and Coastal Health Act of 2000
Best Management Practices
concentrated animal feeding operation
Centers for Disease Control and Prevention
colony forming unit
combined sewer overflow
Clean Water Act
deoxyribonucleic acid
designated use
enterohemorrhagic E. coli
U.S. Environmental Protection Agency
European Union
U.S. Food and Drug Administration
focus forming units
gas chromatography-mass spectrometry
gastrointestinal
geographic information systems
geometric mean
Hazard Analysis Critical Control Point
hepatitis E virus
human immunodeficiency virus/acquired immune deficiency syndrome
high performance liquid chromatography
Hydrological Simulation Program-Fortran
International Life Sciences Institute
immunomagnetic separation
International Organization for Standardization
Liter
Milliliter
Most Probable Number
microbial source tracking
nucleic acid sequence based amplification
National Epidemiological and Environmental Assessment of Recreational
Water Study
National Oceanic and Atmospheric Administration
National Pollutant Discharge Elimination System
non-point source program
National Weather Service
polymerase chain reaction
plaque forming unit
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POP
POTW
QMRA
qPCR
RCT
RDS
RMSE
RNA
SAFE
SCCWRP
SD
SETAC
SRC
SSM
SSO
STEC
SWMM
TMA
TMDL
UAA
U.K.
URI
U.S.
USGS
UV
WQS
WHO
probability of precipitation
publicly owned [wastewater] treatment works
quantitative microbial risk assessment
quantitative polymerase chain reaction
randomized controlled trial
relative standard deviation
root mean square error
ribonucleic acid
Swimming Advisory Forecast Estimate
Southern California Coastal Water Research Project
standard deviation
Society of Environmental Toxicology and Chemistry
sulphite-reducing clostridia
single sample maximum
sanitary sewer overflow
shiga-toxin producing E. coll
Storm Water Management Model
transcription-mediated amplification
total maximum daily load
Use Attainability Analysis
United Kingdom
upper respiratory illness
United States
U.S. Geological Survey
ultraviolet light
Water Quality Standards
World Health Organization (United Nations)
June 2007
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                                  INTRODUCTION


Purpose of the Workshop

Since the U.S. Environmental Protection Agency (hereafter EPA or the Agency) last published
recreational water quality criteria in 1986, there have been significant advances, particularly in
the areas of molecular biology, microbiology, and analytical chemistry.  EPA believes that that
these  new scientific and technical advances need to be factored into the development of new or
revised Clean Water Act (CWA) Section 304(a) criteria for recreation. To this end, EPA  has
been conducting research and assessing relevant scientific and technical information to provide
the scientific  foundation for the development of new or revised criteria.  The enactment of the
Beaches Environmental Assessment and Coastal Health (BEACH) Act of 2000 (which amended
the CWA) required EPA to conduct new studies and issue new or revised criteria, specifically for
Great Lakes and coastal marine waters.

From  March  26 through 30, 2007, EPA  convened a group of 43  national and international
technical, scientific, and implementation experts from academia, numerous states, public interest
groups, EPA, and other federal agencies, at a formal workshop to discuss the  state of the science
on recreational water quality research and implementation.

The purpose of the workshop was for EPA to obtain individual input from members of the broad
scientific and technical community on  the  "critical path" research and  science  needs  for
developing scientifically defensible new  or revised CWA §304(a) recreational ambient water
quality  criteria (AWQC) in the near-term. Near-term needs were defined as specific research
and science activities that could be accomplished in 2 to 3  years so that results  are available to
EPA in time to support the development of new or revised criteria. The new or  revised criteria,
which would be available from EPA in roughly 5 years (2012), must be scientifically sound,
protective  of the   designated  use,  implementable  for broad  CWA  purposes,  and when
implemented, provide for improved public health protection.  (See Appendix A for  the  full
charge to the experts.)  The Agency wants to develop this new or revised criteria in a highly
participatory framework within the next 5 years based on the best available science.

Workshop Design

The Experts Scientific Workshop on Critical Research and Science Needs for the Development of
New or Revised Recreational Water Quality Criteria was designed to be similar in organization
and format to the  Society of Environmental Toxicology and Chemistry  (SETAC) Pellston
Workshops, where technical experts in a particular subject area are invited to  participate  and
evaluate current and prospective  environmental issues.   A  Pellston-type workshop typically
brings together between 40 to 50  technical experts from academia, business, government,  and
public interest groups.  Experts are semi-sequestered for up to a week to facilitate  focused
discussions and individual and collaborative writing of a draft summary report by the  end of the
workshop.   Subject leaders  are then responsible for consolidating,  editing,  producing,  and
distributing the final (formal) workshop proceedings.
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Participant Affiliation Balance

In addition to U.S. and international experts drawn from academia, public interest groups, and
numerous state and other federal agencies, EPA selected several experts from within EPA to
serve in the workgroups (see Appendix B for participant list).   The 43 experts serving in 7
subject areas were supported by a total of 9 EPA resource personnel,  10 note takers, 3 logistics
contractors,  and a professional facilitator.   The  proper balance between EPA  presence and
outside experts was  crucial for keeping the discussions  on  track with EPA's needs from the
workshop while providing ample opportunity for the external experts to voice their opinions and
intellectually explore topics of interest to EPA.

Agenda Overview

The workshop began on Sunday evening,  March 25,  2007, with a  logistics meeting  for the
workgroup chairs, EPA staff, and note takers.  The plenary sessions on Monday served to orient
participants regarding CWA §304(a) AWQC and  EPA's  needs from  the workshop discussions
and these proceedings. Monday afternoon the seven workgroups met for the first time to discuss
interpretation of the charge questions (Appendix A). On Tuesday, all workshop participants met
in a plenary session, which was followed by  workgroup sessions throughout the  day.   The
agenda facilitated and encouraged the workgroups to meet with each other to discuss common
and overlapping issues.  At the end of the day the workshop participants met again in plenary to
hear report-outs from each workgroup chair that described their progress for the day.

Because the seven workgroup topics have  many  overlapping issues, it was important for the
groups to communicate as needed so they could both stay informed of and build on each other's
discussions. In addition to several joint breakout sessions, the workgroup chairs also shared all
of their meals to discuss ongoing progress.  On Wednesday, the workshop participants met once
again in a plenary session to discuss overall progress followed by workgroup breakout sessions
where each group continued discussions and  began writing a draft workgroup report.   The
workgroups continued writing on Thursday. Friday morning, each workgroup turned in a 10 to
20 page draft report and their respective chairs provided an overview of each report regarding the
major themes discussed and critical research needs in a final plenary session.

Seven Workgroup Topics

The seven workgroup topics are presented  in seven chapters in  this  report.  The relationships
between these and other topics are graphically represented in Figure 1.  In Figure 1 shaded boxes
correspond to the seven workgroups.  The alternatives boxes in Figure  1 refer to various possible
indicators that a toolbox approach could provide for each  of the CWA applications. The charge
questions helped the  workgroups to define the scope of their discussions.  The experts were
asked to provide their individual insights on the  state of the science as well as critical path
research that could be completed by  EPA in the next 2 to 3 years. A short description of each
workgroup and the tasks EPA asked them to discuss follows.
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Indicator(s)
Chapter 2


Method(s)
Development
Chapters
               "Acceptable
                 Risk"
               Chapter 5
              Implementation
                Realities
                Chapter 7
Criteria Development
Chapter 1
/
1
\
r

V
Risks to Humans
from Different
Sources
Chapter 4

                                                               Alternatives for
                                                               Water Quality
                                                                Notification
Assessmen
 (based on
 monitoring
   data)
             Figure 1.  Flow Diagram of How the Workgroup Components
             Contribute to the Development of New or Revised Recreational
             Water Quality Criteria.

       Approaches to Criteria  Development - focus  on a toolbox approach as well suggest
       other potential approaches for new or revised criteria development.
       Pathogens, Pathogen Indicators, and Indicators of Fecal Contamination - discuss the
       strengths  and  limitations  of  indicators  of  fecal  contamination,  pathogen index
       microorganisms, and specific pathogens for development of new or revised recreational
       AWQC.
       Methods Development - discuss methods for quantifying indicators and pathogens, such
       as culture-based methods, molecular-based methods (e.g., quantitative  polymerase chain
       reaction [qPCR]), and faster culture-based methods and their applicability for AWQC.
       Comparing Risks to Humans from Different  Sources - discuss  the relative risks of
       illness to humans in waters  contaminated with human fecal material versus animal fecal
       material.
       Acceptable  Risk - discuss the level  of risk  to various populations  that would be
       associated with  numeric AWQC.  EPA was interested in the science necessary to inform
       the policy decision regarding the target risk range and the process through which  the
       policy decision could be reached.
       Modeling Applications  to Criteria Development  and  Implementation - discuss
       predictive modeling approaches and  their potential applications in implementation of
       AWQC.
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    1.  Implementation Realities - identify and consider factors that influence implementation
       of criteria for each of the CWA uses (beach monitoring and notification, development of
       National  Pollutant Discharge  Elimination  System  [NPDES]  permits, assessments to
       determine use attainment, and development of total maximum daily loads [TMDLs].

Background

Clean Water Act §304(a) Recommended Criteria

What are EPA 's Recommended §304(a) Criteria?

CWA §304(a) AWQC are (typically) expressed as numeric concentrations of pollutants.  These
are essentially the  numbers that EPA recommends that States and Tribes adopt in setting their
own Water Quality Standards (WQS) to protect waters for specified designated uses.  State and
Tribal WQS, once approved by EPA, are the effective standards used in CWA regulatory and
non-regulatory programs. Figure 2 provides an overview of CWA WQS.

States and  Tribes  classify waters by  their designated use,1 which includes  "primary  contact
recreation."    States  and Tribes typically define primary  contact recreation to encompass
recreational  activities that could be expected to result in the ingestion of,  or immersion in, a
waterbody (such as swimming, water skiing, surfing, or any other  recreational activity where
ingestion of, or immersion in, the water is likely).

CWA §304(a):

    •   AWQC often are described as  concentrations in the water column and generally have a
       time  and duration component.
    •   AWQC could be expressed as  an annual average  concentration that should  not be
       exceeded; a daily value or seasonal  concentration that should  not be exceeded; or a value
       that should not be exceeded, on average, more than  one time every 3 years (for acute
       aquatic life criteria).
    •   AWQC are often associated with EPA-approved analytical methods.  This is partly
       because without EPA-approved methods to measure concentrations in effluent,  States are
       reluctant to adopt criteria in WQS that are then used in NPDES permits (see more below).

States typically adopt the recommended criteria into their WQS (i.e., regulations promulgated
using state rulemaking processes [similar to Federal regulation development]).

What do States do with these EPA-recommended Numbers and how are they used by States?

Increasingly, because of the dynamics of State rulemaking processes and public  and regulated
community involvement, States are reluctant to adopt EPA's recommended criteria unless the
    1 CWA designated use (DU) classifications are narrative statements describing appropriate intended human
and/or aquatic life and other quality objectives for waterbodies.


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              CWA Water Quality Standards are composed of 3 parts:
              Designated use (DU)
              Ambient water quality criteria (AWQC) to support the DU
              Antidegradation provisions to protect existing uses and high quality waters
                        Designated Use (§303(c))
                           •   Use Attainability Analysis (UAA)
                               required if fishable/swimmable uses
                               not assigned
                           •   Economic and social impacts may be
                               considered
           Criteria for
           protection of
          aquatic wildlife
                          EPA AWQC for protection of human health
                        •  Criteria based on DU
                        •  Separate criteria for each pollutant (§304(a))
                        •  EPA AWQC are guidance only
       In general, States and Tribes have four options (§303(c)):
          •  Adopt EPA §304(a) criteria
          •  Modify §304(a) criteria to reflect regional considerations
          •  Develop their own criteria (scientifically defensible)
          •  Adopt narrative criteria where numeric criteria cannot be determined
      Also:
              EPA reviews changes to State or Tribal criteria for protection of the designated use
              and scientific defensibility
              State and Tribal criteria are not effective for CWA purposes until approved by EPA
              In the case of multiple DUs, criteria must support the most sensitive use
              State-adopted and EPA-approved State and Tribal WQS form the regulatory
              compliance numbers for CWA purposes
    Figure 2.  Clean Water Act: Water Quality Standards Overview.

underlying science supports the desired environmental result and the criteria can be implemented
for all aspects of their CWA Programs.

Under CWA  §304(a)(9), EPA is required to publish new or  revised water quality criteria for
pathogens and pathogen indicators (including a revised list of testing methods, as appropriate)
for the purpose of protecting public health in coastal recreation waters. Coastal recreation waters
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are marine and Great Lake waters designated by States for use for swimming, bathing, surfing, or
similar water  contact activities.   Under CWA §303(i)(l)(B), States  are then required to adopt
new or revised WQS  for those pathogens and  pathogen indicators for which  EPA's  new or
revised criteria have been developed.  States must submit these standards to EPA for approval or
disapproval.  EPA approves the standards if they are scientifically defensible and protective of
the designated use.

Once approved,  State WQS become effective for CWA purposes.  This means that the State-
adopted §304(a) criteria become regulatory standards and are used for several different CWA
purposes, including the following:

    •   §303(d) listings.  Under §303(d) of the  CWA, States prepare lists of waters that  are
       impaired and need TMDLs; States develop the  lists every 2 years and submit them to
       EPA for approval.   If States  determine that waters  are not meeting  applicable water
       quality standards (whether from point or non-point sources of pollution), States are to
       identify those waters as "impaired" under §303(d).
    •   TMDL calculations for impaired waters must be  prepared to implement the applicable
       State WQS.
    •   NPDES permits, which are issued after  State WQS  are in place for a pollutant, must
       have discharge limits as stringent as  necessary  to meet such WQS.  EPA's analytical
       methods are often used to measure compliance with permit limits.
    •   Public Notification  at Beaches.  Under the BEACH Act of 2000, eligible coastal and
       Great Lakes  States  may apply for and  receive  BEACH Act  grants  for  their beach
       monitoring and public notification programs. Those States use their recreational contact
       WQS to determine whether to close an area for swimming or issue a swimming advisory.

Toolbox Approach

EPA's recommended AWQC have to be applicable at a national level.  A toolbox  approach is
under consideration  because of the  potential for greater flexibility in selecting situationally-
appropriate indicators/methods and increased options for implementation, which is desirable for
nationally applicable criteria. A toolbox  allows for the use of varied techniques and approaches
to achieve public health protection.

A preliminary working definition of the Toolbox approach for recreational water quality criteria
might be the following:

       The toolbox approach is a set of potential microbiological (i.e., a microbe plus a specified
       enumeration method) and/or physico-chemical assays that could be employed alone, or in
       certain  combinations, to protect and restore the recreational use of waters. The contents
       of  the toolbox (the "tools") would  be used  by State  public health and water quality
       agencies for beach advisory/closing  program purposes and for all other Water Quality
       Standard related regulatory purposes  under the CWA. The level of risk (or public health
       protection) would be the same regardless of which tool is used.
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Although the toolbox concept allows a context for considering feasibility and applicability of
different indicator and method combinations in developing new or revised recreational  criteria
under CWA §304(a), it is critical that there is an understanding of the relationship among the
different methodologies  for  proper  implementation of the criteria.   For example,  if  EPA
recommended one type of indicator for one set of uses (e.g., culturable enterococci) and also
recommended the use of a DNA-based method (e.g., enterococci qPCR) for other uses, then
there  would have to be an understanding of the meaning  of those  multiple measures  (i.e.,
linkage) in the context of the  overall  CWA §304(a) program. Without a clear understanding of
the linkage  and  context of  different  methods  the entire "toolbox"  concept  becomes
unmanageable from a regulatory perspective.
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                                CHAPTER 1
              APPROACHES TO CRITERIA DEVELOPMENT
            Joel Hansel, Chair, USEPA
            Mark Gold, Heal the Bay, California
            David Kay, University of Wales, U.K.
            John Ravenscroft, USEPA
            William Robertson, Water, Air and Climate Change Bureau, Health Canada
            Jeffrey Seller, Seller Environmental, California
            David Whiting, Florida Department of Environmental Protection
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1.1    Benchmarks for Criteria Development

The workgroup was charged with answering 21 questions and providing a range of alternatives
for the development  of  new or revised national  recreational  ambient water quality  criteria
(AWQC; see Section  1.5 for summary response).  The following six potential approaches that
could be used  or adapted for an approach to  develop new or revised criteria were initially
discussed:  (1) EPA's 1986 approach, (2)  World  Health Organization (WHO), (3) European
Union (EU),  (4) Hazard  Analysis and Critical Point Analysis  (HAACP), (5) Heal the Bay's
Beach Report Card, and (6) EPA's Air Quality Index.  The workgroup members concentrated the
discussions on the three approaches that were deemed most  appropriate for consideration in the
context of Clean Water  Act (CWA)  Section 304(a) ambient water quality  criteria (AWQC),
namely, the WHO approach (with possible modifications), the EU approach (adopted 2006), and
a modified version of EPA's 1986 criteria.   Before the workgroup defined the approaches and
determined the potential  application  of the three alternative approaches,  workgroup members
agreed that it was  critical to identify desirable attributes or benchmarks for the criteria. The
benchmarks or attributes that were identified are summarized below.

    1.  The criteria are health-based.  The workgroup demonstrated a preference that the criteria
       be as directly  as possible anchored to health effects  demonstrated  in epidemiology
       studies.
    2.  The criteria  should demonstrate utility for and be  compatible with  all of the CWA
       §304(a) criteria (as amended by the Beaches  Environmental Assessment  and Coastal
       Health Act of 2000 [BEACH Act]) needs, including  water quality assessment for public
       notification at beaches in a timely  manner,  assessment for impaired waters listings,
       development of total maximum daily load  (TMDL) development and implementation,
       and development of National Pollution Discharge Elimination  System (NPDES) permits.
    3.  The criteria should be scientifically defensible for application in a wide variety  of
       geographical locations  (climatic conditions),  including  fresh and  marine  waters, and
       temperate, subtropical, and tropical waters.
    4.  The criteria be  sufficiently robust and flexible so that they can be  configured to protect
       the  public health  of those exposed to recreational water impacted by sewage effluent,
       concentrated animal feed operation (CAFO)  contaminated runoff, non-point sources (e.g.,
       agriculture  [non-CAFO],  urban runoff) and waters not impacted by anthropogenic
       sources.
    5.  The criteria should be sufficiently robust and flexible so that they can be configured to
       provide  regulators the ability to protect susceptible  (sensitive)  subpopulations such as
       children  and  immunocompromised  individuals.    Commonality  was  found  among
       workgroup members that protecting the health of children was of paramount concern.
    6.  The criteria are associated (linked) with analytical methods that are reliable, robust, and
       provide reproducible results.
    7.  The criteria  should protect primary  contact recreation  in freshwaters, marine  waters,
       temperate, subtropical, and tropical waters equally. Similarly, the criteria should provide
       equal protection those exposed to effluent, urban runoff, and/or non-point source runoff
       impacted waters via primary contact recreation.
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The workgroup members agreed that all seven of the above attributes are critical considerations
for criteria  development.   In  assessing the  potential  application  of each  of the  proposed
alternatives, it is important to keep in mind that criteria applied to these alternatives are assumed
to be consistent with all of the  above attributes (or at least most of them) before  the final
frameworks and criteria are developed.  The likelihood that some of these attributes will not be
met in the  near-term  seems  to make  the WHO or  EU approaches  more  suitable for
implementation.

The workgroup expressed the opinion that EPA should  release the new or revised criteria and
implementation guidance concurrently to provide clarity  to States on how the criteria should be
used for regulatory and public notification needs.

1.2    Integration of Workshop Components

A summary of the interactions between the various  subject areas addressed in this workshop is
presented in Figure 3.  In Figure 3  shaded boxes correspond to the seven workgroups.  The
alternatives boxes in Figure 3 refer to various possible indicators that a toolbox approach could
provide for each of the CWA applications. Briefly, the Pathogen/Pathogen Indicator workgroup
proposes indicators that may have utility for criteria development (see Chapter 2).  In doing so,
they consulted with the Methods Development workgroup members (see Chapter 3) to assure
that validated methods  are  or  could be available  and  usable for the implementation of the
proposed parameter.  Different  methods have different specificities for identifying whether the
source of fecal contamination is human- or animal-based.  The Comparing Risks workgroup
provided information  on the relative risks  to human health from  different sources  of fecal
contamination (Chapter 4).  Once identified,  the pathogen/pathogen indicator and the associated
method are used during the criteria  development process. Another critical  component in the
criteria development  process is the identification  of  a risk  level.   Information  from the
Acceptable Risk workgroup (see  Chapter 5) on how to develop "acceptable risk" thresholds is
used in this context during the criteria development process. The Modeling workgroup discussed
how predictive modeling can be used  to inform criteria approaches and to provide information on
water quality notification (Chapter 6).  Once these pieces  were integrated, an initial check was
conducted against the  suggestions and concerns of the Implementation Realities workgroup (see
Chapter 7) members to help ensure that the potential for criteria development does not conflict
with actual "on the ground" implementation.

As discussed in the Introduction to these proceedings, recreational AWQC are used for a number
of purposes.   First, these criteria are  used to make assessment determinations under CWA
§305(b) and §303(d).2  Within this regard and depending  on  the  framework, a number of
alternate  indicators or methods may be used  to assist in making the determination  as to the
overall quality of a waterbody  and the compliance with  the underlying criteria.  Second, these
criteria are used to determine permit  limits for NPDES permit holders and for TMDL purposes.
Finally, these  criteria are used  to determine the acceptability of the water for direct primary
contact recreation.  Conceptually, alternative  indicators, including models, could also be used for
these purposes.
    2 http://www.epa.gov/owow/tmdl/tmdlO 1037


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                           Indicator(s)
               "Acceptable
                 Risk"
                            Assessmen
                             (based on
                             monitoring
                              data)
          Method(s)
         Development
Criteria
Development
/
\
\
r

V
Risks to Humans
from Different
Sources

                    Alternatives for
                    Water Quality
                     Notification
                                                        Predictive
                                                        Modeling
                         Other
                        Indicators
              Figure 3.   Flow Diagram of How the  Workgroup  Topics
              Contribute to the Development and Implementation of New or
              Revised Recreational Water Quality Criteria.

1.3    Summary of Currently Available Water Quality Criteria Setting Approaches

The three alternatives that were identified by the workgroup  were a modified WHO approach,
the EU approach, and  a modified version of the  EPA 1986 approach because  all of these
approaches are largely based on peer reviewed epidemiology studies and some version of each of
these frameworks are in use currently in at least one country.

Workgroup members generally agreed that all three criteria development approaches are feasible
providing the criteria meet the becnhmarl/attributes  listed above.  Although  the workgroup
briefly discussed other approaches such as the EPA's Air Quality Index, HAACP, and Heal the
Bay's Beach Report Card approaches, none of these approaches were deemed to be appropriate
for the  desired purposes for a variety of  reasons,  including lack of applicability for criteria
development.

1.3.1   WHO Approach for Water Quality Criteria Setting

The  WHO   has  been  concerned with  health  issues associated with  recreational   water
environments for many  years and has published several  influential reports that represent a well
accepted view among international experts  (Priiss, 1998). The WHO approach provides a basis
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for  standard  setting  in light of local and regional circumstances,  such  as the  nature  and
seriousness of local endemic illness, exposure patterns,  and competing health risks  that are not
associated with recreational water exposure.

The WHO  approach is based on the perspective that recreational water quality and protection of
public health are best described by  a combination  of sanitary inspection and microbial  water
quality  assessments (the WHO  [2003]  Guidelines use enterococci  as the  fecal  indicator of
choice;  see Table  1).  This approach considers possible sources of pollution in a  recreational
water ("sanitary  inspection category" in Table  1), as well as observed levels of fecal pollution
("microbial water quality assessment category" in Table 1), and combines them into a five-level
classification scheme for recreational water environments.  To date, the classification system has
been used primarily to "grade" recreational waters and to provide an assessment for regulatory
compliance purposes.  This approach however,  also could be  adapted for other CWA  §304(a)
applications such as NPDES permitting and TMDL development.

The microbial water quality assessment criteria  are  based on a banded system, where the band
divisions are equivalent to a risk of acquiring gastrointestinal (GI) illness for (A) <1  case in 100
exposures,  (B) <1  case in 20 exposures,  (C) <1 case in 10  exposures, and  (D) >1 case in 10
exposures.   The  95th percentile value was selected as an appropriate descriptor of the microbial
probability density function because it is easily understood to be the probability of encountering
          Table 1.  WHO Classification Matrix for Integrating Microbial Water
          Quality as Measured by Enterococci Density with Sanitary Inspection
          Category.

Sanitary
Inspection
Category
(susceptibility to
faecal influence!
Very low
Low
Moderate
High
Very high
Exceptional
circumstances
Microbial Water Quality Assessment Category
(95th percentile intestinal enterococci;' 100 ml)
A
<40
Very good
Very good
Good2
Good2
Follow up2

B C
41-200 201-500
Very good Follow up1
Good Fair
Good Fair
Fair2 Poor
Fair2 Poor
Action
D
>500
Follow up1
Follow up1
Poor
Very poor
Very poor

Exceptional
circumstances
Action
          Notes;
          1 implies non-sewage sources of faecal i indicators (e,g, livestock), and this should be verified (section 4,6.2).
          2 indicates possible discontinuous/sporadic contamination (often driven by events such as rainfall). This is most commonly
           associated with Combined Sewer Overflow (CSO) presence. These results should be investigated further and initial follow-
           up should include verification of sanitary inspection category and ensuring samples recorded include "event" periods.
           Confirm analytical results. Review possible analytical errors (see section 4.6.2),
          3 In certain circumstances, there ma1/ be a risk of transmission of pathogens associated with more severe health effects
           through recreational water use. The human health risk depends greatly upon specific (often local) circumstances. Public
           health authorities should be engaged in the identification and interpretation of such conditions (section 4.6,5).
          4 Exceptional circumstances (see section 4,6.5) relate to known periods of higher risk, such as during an outbreak with a
           pathogen that may bewaterfaorne, sewer rupture in the recreational water catchment, etc Under such circumstances, the
           classification matrix may not fairly represent risk/safety.

          SOURCE:  WHO, 2003.
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polluted water and focuses on water quality that is likely to cause illness (i.e., greater probability
of illness associated  with increasing density of human sources of fecal  pollution).  The WHO
levels of risk for the bands described above were selected based on a series of science policy
decisions  in consultations with numerous international  experts and  were intended to be
reasonable for both the developed and developing world. The expectation in the United States is
that the "acceptable risk" (see Chapter 5) levels would be similar or more protective than the risk
levels adopted by other developed countries.  The methodology used to derive the 2003 WHO
Guideline values is summarized in Appendix C.

The sanitary inspection  category  is intended to  classify the  risk of illness  caused by fecal
pollution in a recreational  waterbody,  although human fecal  pollution  will  tend to drive the
overall sanitary inspection  category derived for an area.   WHO experts believe that the three
most important sources of human fecal contamination of recreational water environments for
public  health purposes are typically sewage, riverine discharges, and direct contamination from
bathers.  Sanitary inspections  are required to address those  sources as  well as others, and
inspections should take on a  tiered approach, dependent  on the level  of perceived risk and its
uncertainty.  For example, if human and domestic fecal pollution is considered low based on land
uses, but fecal indicator counts  are relatively high, further exploration  of the  source(s) and  their
relative risks would be recommended. This higher level of examination (tier) may utilize more
expensive methods  and  approaches and further  cycles  (tiers) of investigation as necessary.
Based on the results of the sanitary inspections, recreational waters are ranked (from very low to
very high) with respect to evidence for the degree of influence of fecal material.

1.3.2   EU Approach for Water Quality Criteria Setting

The EU broadly  adopted the 2003 WHO  Guidelines in  formulating  the 2006 Bathing Water
Directive. A summary of the European Commission Directive  is provided in Appendix D.  The
approach incorporates the following fundamental elements:

    •   The  EU  starts  with the WHO risk assessment framework, but does not include the
       sanitary  inspection category  information  for  the purposes  of  recreational water
       classification.  Instead, it uses only the microbial water quality assessment information to
       characterize the probability of exposure to human pathogens.
    •   The EU approach used the WHO microbiological  criteria for marine waters and applied
       the same risk assessment framework to new epidemiological data to derive standards for
       fresh recreational waters.
    •   The EU approach allows sample discounting.  Under  discounting, numeric excursions
       above the water quality standards that are predicted and/or measured do not count against
       the waterbody for compliance determination  (i.e., such values are  discounted from the
       data set prior  to calculation of the 95th percentile, but only 15%  of scheduled samples can
       be so discounted).  Sample discounting is allowed when a predictive model,  source
       reduction plan, and communication management system are in place to inform the public
       about short-term pollution events derived during predictable conditions (e.g., rainfall).

The EU  Bathing Water Directive (7/EU/EEC; dated February 15, 2006)  is currently being
translated by Member States for implementation  (EP/CEU, 2006).  The Directive  establishes
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separate  numerical  microbiological  criteria  for fresh  (inland)  and  marine  (coastal  and
transitional) bathing waters for the 24 EU Member States (Table 2). The numerical values are
based on epidemiological studies reported by Kay et al. (1994) and Wiedenmann et al. (2006)—
the former was used by WHO in formulating their Guidelines (Kay et al., 2004; WHO, 2003).

Table 2. Numerical Microbiological Water Quality Assessment Classification for
Fresh (Inland) and Marine (Coastal and Transitional) Bathing Waters for the 24 EU
Member States.
Inland (Fresh) Waters
Indicator
(Intestinal) enterococci (cfu/100 mL)
E. co//(cfu/100mL)
Excellent
200*
500*
Good
400*
1,000*
Sufficient
360**
900**
Coastal and Transitional (Marine) Waters
Indicator
(Intestinal) enterococci (cfu/100 mL)
E. co//(cfu/100mL)
Excellent
100*
250*
Good
200*
500*
Sufficient
200**
500**
Notes:  * = Based on a 95th percentile evaluation; ** = Based on a 90th percentile evaluation to
reduce the risk of statistical anomalies when using a small data set, which also allows lower limit
values for enterococci and E. coll densities in inland waters to be classified as sufficient versus
good microbiological water quality.
Source:  Adapted from EP/CEU (2006).

1.3.3  EPA 1986 Water Quality Criteria Setting

In the late 1970s and early 1980s, EPA conducted  public  health studies  evaluating several
organisms as possible indicators, including total and fecal coliforms, E. coli,  and  enterococci.
The studies  showed that enterococci  and  E.  coli   are  the  best  predictors of GI  illness
(gastroenteritis)  in  sewage effluent-impacted freshwaters, while enterococci were  the  best
predictor in sewage-impacted marine waters.  Gastroenteritis describes a variety of diseases that
affect  the GI tract  and are rarely  life-threatening;  self-limiting symptoms  include nausea,
vomiting, stomachache, diarrhea, headache, and fever.  Based on these studies, EPA published a
criteria document, Ambient Water Quality Criteria for Bacteria - 1986, recommending the use
of these bacterial indicators in ambient water quality criteria values for the protection of primary
contact recreation (US EPA,  1986).   Table 3 summarizes the Water Quality Standards for
Coastal  and  Great Lakes Recreation Waters Rule (US EPA,  2004) that requires States and
Tribes to adopt the 1986 AWQC for Bacteria.

States  and Tribes generally define  their designated  use  of "primary contact recreation"  to
encompass recreational activities  that could be expected to  result in  the  ingestion  of,  or
immersion in, water, such as swimming, water skiing,  surfing, or any other recreational activity
where ingestion of, or immersion in, the water is likely.

EPA derived standards that implied an acceptable excess illness probability of 0.8% in swimmers
exposed in freshwater and  1.9% in swimmers exposed in marine waters.  EPA's 1986 bacteria
criteria document indicates the  illness rates are "only  approximate"  and that the Agency based
the 1986 values that appear in Table 3 on these approximations.
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Table 3. Summary of EPA's 1986 Recommended Water Quality Criteria for Bacteria and
2004 Rule
Indicator
Swimming-
Associated
Gastroenteritis
Rate per 1,000
Swimmers
Geometric Mean
Steady State
Geometric Mean
Indicator
Density
Single Sample Maximum Allowable Density
Designated
Beach Area
Moderate:
Full Body
Contact
Recreation
Lightly Used:
Full Body
Contact
Recreation
Infrequently
Used: Full
Body Contact
Recreation
Freshwater
Enterococci
E. coli
8
8
33
126
61
235
78
298
107
409
151
575
Marine Water
Enterococci
19
35
104 158
276
501
Source: US EPA (2004).

EPA's 1986 bacteria AWQC document provides geometric mean densities as well  as  four
different  single  sample maximum values (representing values below which  an increasing
percentage of  single values are expected to  fall  if the geometric  mean of  samples from the
waterbody is equal to  the geometric  mean  criteria).   The 1986  bacteria AWQC  document
categorizes the  single  sample  maximum  values based levels  of beach usage as follows:
"designated bathing beach" for the 75% (most conservative) confidence level,  "moderate use for
bathing" for the 82% confidence level,  "light use for bathing" for the 90% confidence level, and
"infrequent use  for bathing" for the  95% confidence level.  The lowest confidence level
corresponds to the highest level of protection.

In the 1986 AWQC context, single sample maximum criteria are water quality assessment tools
that provide a sense of when the water  quality in a waterbody is not consistent with the AWQC.
Insights based on single observations  are very difficult because of the expected variability of
fecal indicators.  For instance, if the long-term geometric mean concentration of enterococci in
the water at a marine beach is 35/100 mL and  the log standard deviation is  0.4, then there is an
18% chance that the concentration of enterococci in a single sample  would be  over 158/100 mL.
The higher the single sample maximum, the lower the probability that a single sample exceeding
that value would occur as part of the normal random variability of samples (US EPA, 2006).

Since publication of the 1986 criteria, many States have expressed concern that the current fecal
indicator/illness rate relationships identified in the epidemiology studies leading up to the 1986
criteria are not appropriate or representative  of  all U.S. waters.  For example, States have
concern that the most appropriate indicator in tropical waters may be different than in temperate
waters, and that appropriate levels of indicators may be different in waters where human fecal
waste predominates animal waste.  Other identified issues are as follows:

   •   lack of clear, timely, and flexibile guidance regarding use of  the single sample maximum
       values and differing risk levels;
   •   no  EPA-approved analytical methods for use in wastewater for the indicator bacteria;
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    •  lack of data to correctly assess the applicability of the 1986 bacteria criteria to flowing
       waters; and
    •  lack of data to quantify the risk associated with contributions from nonhuman sources of
       fecal contamination as well as lack of flexibility to adjust the criteria for water bodies that
       do not receive human sources of fecal contamination.

1.3.4  Summary of Proposed Criteria Development Approaches

Workgroup  members  developed  a  summary  of the  three proposed  criteria  development
approaches, including strengths and limitations (Tables 4a and 4b).
    Table 4a.  Summary of Proposed Criteria Development Approaches:
    Strengths  and Limitations
       Criteria
      Approach
    Science
  Supporting
  Approach
         Strengths
      Limitations
    World Health
    Organization
    (WHO, 2003)
Fleisher et al.,
1996
Kayetal., 1994,
2004
WHO, 1999
Wyeretal., 1999
  Flexible
  Most comprehensive of
  available methods
  Adopted by other countries
  Incentives for beaches to
  upgrade
  Allows more site appropriate
  protection of health
Sanitary inspection
component is qualitative; not
quantitative
Greatest data needs
Would need to adapt
potentially complex system to
wide range of conditions in
U.S.
Potential implementation
issues
    European Union
    (EP/CEU, 2006)
Fleisher et al.,
1996
Kayetal., 1994,
2004
Wiedenmann et
al., 2006
WHO, 1999,
2003
  Flexible
  Relatively straightforward
  Incentives for beaches to
  upgrade
  Adopted by other EU
  Member States
Discounting system has no
direct precedent in the U.S.
Would need to devise robust
and acceptable discounting
scheme
Potential implementation
issues
    Current U.S.
    Criteria
    (US EPA, 1986)
US EPA, 1983,
1984
• Relatively straightforward
• Currently in place in most
  states, new implementation
  issues less likely
• Fewest data requirements
Allows less flexibility
Single sample max (75th
percentile) has been criticized
from implementation
perspective
Credibility concerns in many
parts of the U.S.	
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   Table 4b. Summary of Three Proposed Criteria Development Approaches:
   Benchmarks
Criteria
Approach
World Health
Organization
(WHO, 2003)
European Union
(EP/CEU, 2006)
Current U.S.
Criteria
(US EPA, 1986)
Criteria Attribute
Health-based
CWA §304(a) applications
Geographic variability
Point vs. non-point
Multiple subpopulations
Uniform risk across waterbody types
Linked to method that is validated
Health-based
CWA §304(a) applications
Geographic variability
Point vs. non-point
Multiple subpopulations
Uniform risk across waterbody types
Linked to method that is validated
Health-based
CWA §304(a) applications
Geographic variability
Point vs. non-point
Multiple subpopulations
Uniform risk across waterbody types
Linked to method that is validated
Approach Compatible with
Attribute
Yes
Most challenging - unclear how different
grades for beaches would be interpreted
with respect to impaired waters; for
example, TMDLs would need to be
considered.
Not with current indicator, ongoing
research could fill gaps
No, epidemiological data would be
needed
Could be, but in current configuration
children not analyzed separately
Yes
Yes currently, but will also depend on
future indicators
Yes, but differential risks from different
sources of fecal contamination is not
included, thus, this approach is less
health-based than WHO approach
Yes, but challenging for same reasons as
WHO approach
Not with current indicator, ongoing
research could fill gaps
No
Could be, but in current configuration
children not analyzed separately
Yes
Yes currently, but will also depend on
future indicators
Yes, but concern about single sample
standard, also concerns that differential
risks from different sources of fecal
contamination are not included
Yes
No
No
No
No, fresh and marine recreational waters
have different "acceptable risks"; this
could be addressed in new or revised
criteria
Yes currently, but will also depend on
future indicators
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1.3.5   Other Approaches Considered

As  noted previously, the workgroup considered a number of other frameworks and approaches
that might be applicable to criteria development, including the following:

    •   Hazard Analysis and Critical Control Point Principles (HACCP);
    •   Heal the Bay Beach Report Card; and
    •   EPA Air Quality Index.

The EU, EPA (1986) criteria, and the WHO approaches are already being used for the intended
purpose, either in the United States or  other countries.  The other possible approaches listed
above have not been applied in a regulatory framework for proposed water regulation and would
need to be thoroughly  assessed to determine their utility or applicability to derive recreational
water quality criteria.   The workgroup members felt that it was beyond their ability to conduct
such an assessment at this time.  One workgroup member noted that the Heal the Bay approach
was never intended for use in all regulatory purposes and would not be recommended for such.

1.4    Summary of Critical Issues to be Resolved in Applying  Available Water Quality
       Criteria Approaches

No matter which recreational water quality criteria development approach is selected, a number
of research needs have  to be met before  criteria development can reach completion. Additional
epidemiological studies that take into account marine waters, subtropical and tropical  waters,
urban runoff, and non-point sources of contamination will need to be completed in the next 2 to 3
years to provide the health effects data  necessary if nationally applicable are to be developed.
Further testing of quantitative polymerase  chain reaction (qPCR)  methods to detect enterococci
and/or any additional proposed indicators under the conditions listed above also is  critical.  The
epidemiological studies should also include (1) culture-based methods in addition  to molecular
methods for  enterococci;  (2) culture and  molecular-based methods for E.  coli in fresh water
studies  because  national  freshwater criteria and  numerous  States currently use E.  coli in
recreational criteria and including E. coli would maintain a level of consistency with the existing
CWA  §304(a)  guidance;  and (3) sensitive subpopulations to the extent  feasible, including
children at a minimum.

Other research gaps that can be filled in the next few years include, but are not limited to, fate
and transport of molecular-based indicator organisms in  wastewater treatment plants and in the
ambient aquatic environment.  Workgroup members expressed a significant concern about the
issue of conservation of measurable genetic material throughout the treatment process because of
the regulatory ramifications in the NPDES, water quality assessment, and TMDL programs of
moving to molecular-based criteria.

Another research need  is for effective predictive models for beach water  quality forecasting to
notify the public of the potential health  risks of recreational water contact.  The current use of
single sample assessments using culture-based  methods has proven to be largely ineffective for
public notification of beaches purposes because of the time required for sample processing (i.e.,
sample transportation to a laboratory, 18  to 24 hour incubation time, and time required for results
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to reach and be evaluated by a decision maker).  In addition to their development,  the models
need to be adequately field verified and calibrated.  Ideally, regional models can be developed,
but if predictive models can only be developed on a site specific basis over the next 3 years, the
data needed to develop, field verify, and calibrate the models should not be  cost prohibitive to
collect. At a minimum, recreational beach managers should consider a simple, predictive rainfall
model to more effectively protect public health.

Workgroup  members emphasized that  a sanitary  investigation3  approach  to  characterize
drainages to primary contact recreational waters would prove useful for at least the WHO criteria
development framework.  A simple to implement, quantitative-based sanitary investigation, in
conjunction with  the health risk data from the proposed additional epidemiology studies, may
enable the development of  source specific risk parameters for criteria development.   To clarify
expectations for these surveys, a standardized and relatively simple approach would need to be
developed that includes fecal bacteria source characterization (publicly owned  [wastewater]
treatment works  [POTWs],  storm drain outfalls, CAFOs, on-site wastewater treatment systems
["septic systems"], agriculture,  etc.) on a  drainage-wide basis,  distance of sources to primary
contact recreational  waters, flow,  developed  area in the drainage,  and the  frequently  high
variability in water quality from day to day.  Additional sanitary investigation components such
as source identification and source tracking4 may not need to be implemented unless there is a
need in the regulatory process to implement a TMDL or to protect the public health of swimmers
at chronically polluted beaches.

The following summary assumes that all  of  the approaches  encompass and achieve the
benchmarks outlined in Section  1.1 to the extent feasible.

1.4.1  Summary of Application of WHO Approach for U.S. Criteria  Setting

The general framework  described by the WHO (2003) would be applicable  to U.S. criteria
setting  in  the near-term  given that the following research is  conducted and  science policy
decisions are made:
    3 This is similar to Canada's "Environmental Health and Safety Assessment" in Appendix A of Guidelines for
Canadian Recreational  Water  Quality (MNHW,  1992).  Although the WHO (2003) uses the term "sanitary
inspection," some workgroup members expressed concern that use of that specific term or the related term "sanitary
survey" might imply adoption of all the protocols for sanitary inspections/surveys from other contexts. Thus, the
term "sanitary investigation" was selected for use in these proceedings to minimize preconceived assumptions
regarding the  nature of the sanitary investigation and is used to refer to a quantitative approach to gauge watershed
susceptibility  to fecal influence.  However, "sanitary inspection" is used when the WHO approach is described.
    4 Although there is not universal acceptance of definitions for microbial source tracking and microbial source
identification, the Methods workgroup discussions assumed the following working definitions: source identification
is determination of the type of animal (sometimes human versus nonhuman, sometimes more specific) that produced
the fecal contamination.  It does not include determining where in the watershed that material came from, but it does
suggest what  to look for upstream.  Source tracking is determination of the actual source of fecal matter, such as a
leaking pipe, a septic system, or a cow pasture. It typically involves using some of the marker techniques associated
with source identification, but not necessarily.  Source  tracking can also be achieved through extensive spatial
sampling with existing indicators or (for example) through use of dye tablets in septic systems.
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    1.  Analyze epidemiological data to determine the values of water quality that correspond to
       the identified levels of "acceptable risk" for the indicator of fecal contamination using the
       selected method(s).
    2.  Identify  a suitable indicator  of  fecal  contamination or  suite  of fecal indicators
       (particularly  for  subsequent tiers  of investigation).   This information  needs to be
       epidemiologically based.
    3.  Identify "acceptable risk" levels. Choosing an "acceptable risk" level is a policy decision
       that is informed by science (e.g., epidemiology studies). See Chapter 5 for a discussion
       of the process through which an "acceptable risk" level could be chosen.
    4.  Derive a quantitative sanitary investigation category rather than a qualitative process;
       also, the sanitary investigation should be standardized nationwide.
    5.  Statistically validate the linkages between different indicator/method combinations for
       different  CWA  §304(a)  purposes  to  facilitate  translation between  the  various
       indicator/methods.
    6.  Consider and develop a recreational water quality reclassification scheme, if appropriate.
       If such a  reclassification scheme is  appropriate,  a  management system would be
       necessary to facilitate implementation of beach advisories and to ensure informed choice
       regarding beach use.
    7.  Develop a  public information management system and  a beach signage provision.  The
       purpose of these programs would be to represent bathing water characteristics derived
       from a "bathing water profile" and historical water quality.
    8.  Institute  a monitoring  program to acquire bathing water  quality data for numerical
       compliance assessment purposes.
    9.  Release  CWA §304(a) criteria guidance and  associated  implementation guidance
       concurrently.

To apply the WHO (2003) approach for future criteria setting, the following issues will need to
be considered in detail  and expanded:

    1.  Develop a process to determine how waterbodies get listed as impaired.
    2.  Determine  the appropriate number of categories for microbial  and sanitary investigation
       categories.
    3.  Possibly  change several qualitative determinations  in the framework (i.e., very good,
       good, fair) to  less descriptive terms (i.e., Category I, Category II, etc.).
    4.  Develop a process for categorization of NPDES dischargers (consideration  for default to
       most restrictive category).
    5.  Determine  how to use different  indicator/method  combinations for  CWA  §304(a)
       applications and translate to each other to ensure equivalent levels of protection.
    6.  Determine  whether health risks from nonhuman fecal sources  are substantially different
       than from human sources.
    7.  Determine  what is  the most appropriate metric for expressing  the water quality criteria
       (geometric mean, upper percentile, a combination of those and/or other)
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    8.  Determine  how  to  make  water quality public notification decisions (this  is likely a
       function of the indicator/method combination[s] that are employed and the strength of a
       predictive model).
    9.  Develop a well described and vetted quantitative sanitary investigation guidance; here the
       workgroup  members suggested a tiered approach that allows for varying levels of effort
       based on likely benefit from the assessment (high and low risk should be easier to assess
       [i.e., beaches downstream from POTWs or urban catchments would be high risk, and
       beaches downstream of catchments  with  100% natural  sources would be  low risk]).
       Although completion of the sanitary  investigation does not need to be required, surface
       waters would default to the most restrictive  criteria until  such time  as  a completed
       investigation provides justification for changing the applicable criteria.
    10. Develop a well described and vetted recreational water quality reclassification scheme.

1.4.2   Summary of Application  of EU Approach for U.S. Criteria Setting

The general  framework described by  the EU (EP/CEU,  2006) would  be applicable to U.S.
recreational water quality criteria setting given the same research and science policy decisions as
described above for the WHO except (1) a classification scheme based on a quantitative sanitary
investigation would not be necessary because the sanitary inspection category is not used to
determine the beach classification, and (2) it would not be necessary to determine whether health
risks from nonhuman sources of fecal contamination are substantially different than from human
sources, because the beach classification is based on microbial densities only..

To apply the EU approach for future criteria setting the same issues described above will need to
be considered in detail and expanded, with the following exceptions:

    1.  Reform the microbial  categories to fit U.S.  waters,  do not  include  the "sufficient"
       category of EU Directive EEC/7/2006.
    2.  Determine  if a  discounting scheme  is  necessary and appropriate  (e.g., elimination of
       monitoring data  for compliance purposes), and if so, then there is  a  need to determine
       how to make it most protective of public health.

1.4.3   Summary of Application  of EPA 1986 Approach for U.S. Criteria Setting

The current EPA (1986) framework described previously would be applicable to new or revised
U.S. criteria development with the following  modifications:

    1.  Develop additional indicators and analytical methods that would be applicable to tropical
       and temperate waters and also for use in wastewater.
          a.   Base additional indicators and methods on health risks (i.e., occurrence would be
              correlated with rates of illness from epidemiological studies).
          b.  Ensure   that  the   revised  criteria   framework  specifies   the  appropriate
              indicator/methods combination for the various waters.
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    2.  Consider more timely methods  for beach monitoring and  water quality notification.
       Currently, there is no scientific evidence supporting beach water quality determinations
       based on, at best, day-old (culture-based) data.
          a.  If molecular-based  methods are used,  then fate  and transport  data  for  that
              indicator using that method would be needed.
          b.  If molecular-based methods are limited to  beach monitoring and water quality
              notification, then these methods must be linked somehow to the methods used for
              the other CWA  purposes.  Currently,  very limited data are available for this
              purpose.
          c.  If predictive modeling is used in water quality notification programs, the models
              need to be adequately field-verified and calibrated.
    3.  Risk threshold
          a.  Any final  recommendation  for CWA §304(a) criteria must be health-based and
              derived from the available epidemiological data.
          b.  If a single sample criteria is used, it should  be of similar stringency to any other
              measure used (e.g., geometric mean) and the single sample criteria should account
              for the expected frequency of exceedance (e.g.,  if the  single sample criteria is
              based  on a 95th percentile, a 5% exceedance should be allowed without invoking
              compliance ramifications).
          c.  Consider risk to sensitive subpopulations (e.g., children) in the determination of
              the risk threshold.
          d.  The risk of illness should be the same for swimmers  in all types of waters (i.e.,
              marine, fresh, temperate, tropical, etc.) exposed to all types of fecal contamination
              sources (e.g., point, non-point).
          e.  Secondary contact recreation waters:
                 i.  Acquire data to show health risks associated with limited, but defined
                    levels of contact and/or incidental exposure.
                 ii.  Data  can be  from epidemiological studies or estimated using quantitative
                    microbial risk assessment (QMRA).
                iii.  Develop a more accurate descriptor of what constitutes secondary  contact.
    4.  CWA §304(a) AWQC recommendations and associated implementation guidance should
       be released concurrently.

1.5  Summary of Response to Workgroup Charge Questions

See Appendix A for the complete (original) charge questions.

1.     What approaches exist currently for setting limits of pollutants that may be relevant for
       developing nationally  recommended recreational water  quality criteria?  Consider
       approaches used for other  kinds of pollutants  in water,  in other environmental media,
       and by other  countries as well as approaches being implemented by States.  What are
       the pros and cons of each of these approaches?

       •  European  Union Revised Bathing Water Directive 2006/7/EC


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       •  Hazard Analysis and Critical Control Point Principles
       •  Heal the Bay Beach Report Card
       •  EPA Air Quality Index
       •  EPA Ambient Water Quality Criteria for Bacteria - 1986
       •  WHO Guidelines for Safe Recreational Water Quality Environments.  Volume  1
          Coastal and Fresh  Waters

The EU (EP/CEU,  2006), (US EPA) 1986 criteria, and the WHO (2003) approaches are already
being used for the  intended purpose,  either in the United States or other countries.  The other
possible approaches listed above  have not been applied in a regulatory framework for proposed
water regulation and would need to  be  assessed to determine their utility or applicability to
derive new or revised recreational water quality criteria.

2.     Which of  these  approaches is  most  applicable  and  appropriate for  developing
       nationally recommended  recreational water quality criteria in the near-term? Why is
       this approach on balance considered the most applicable and appropriate?

Workgroup members  identified  the  following critical benchmarks for water quality criteria
development:

       •  Be applicable to human health effects;
       •  Fulfill the needs of Clean Water Act (CWA)  and  meet the  associated  regulatory
          purposes  (monitoring,  permitting,  total maximum  daily loads  [TMDLs],  and
          §303(d));
       •  Address geographic variability (i.e., tropical,  subtropical, and temperate regions);
       •  Address  potential   differences  between  point  and  non-point  sources  of fecal
          contamination and associated risk;
       •  Consider risks to susceptible subpopulations, primarily children; and
       •  Be based upon methods that are reliable and reproducible.

Based on these benchmarks, workgroup members further identified three approaches  for further
consideration—European Union Revised Bathing Water Directive 2006/7/EC (EP/CEU, 2006),
EPA  Ambient  Water Quality Criteria for  Bacteria  - 1986,  and the 2003  World Health
Organization Guidelines for Safe Recreational Water Quality Environments.  Volume 1 Coastal
and Fresh Waters.  Table 4a summarizes the advantages and disadvantages of each approach and
is provided in Section 1.3.4.

3.     For those approaches  identified as applicable and appropriate, what is the science that
       supports the approach? Is that science sufficient and of adequate quality?

Epidemiological research identified to support the best selected approaches was:

       •  European Union Revised Bathing Water Directive (2006/7/EC; EP/CEU, 2006)
          o  Fleisheretal. (1996)


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          o  Kay etal. (1994)
          o  Weidenmann et al. (2006)
          o  Wyer etal. (1999)
       •  EPA Ambient Water Quality Criteria for Bacteria - 1986
          o  US EPA (1983)
          o  US EPA (1984)
       •  World Health Organization  2003 Guidelines for Safe Recreational Water Quality
          Environments. Volume 1 Coastal and Fresh Waters
          o  Fleisheretal. (1996)
          o  Kay etal. (1994)

All members of the  workgroup  agreed that the research reports  listed  above support the
respective approaches but some members questioned whether the research identified above was
adequate  to  meet  all of  the  identified  benchmarks.    They  also  agreed that  additional
epidemiological and modeling work needed to be performed in order to successfully implement
any of the approaches  above  for future  new  or revised recreational water quality  criteria
development in the United States.

4.     Are there  any critical research  and science needs  that  should be  addressed in
       developing or  selecting  an appropriate approach? Can this research be completed n
       time to be used in criteria development in the near term?

The workgroup members identified the following research and science needs to support the
suggested approaches.

       •  Information on the geographic  applicability of fecal indicators  for assessing health
          risks at tropical and subtropical  fresh  and marine recreational bathing areas impacted
          by point and non-point sources of fecal  contamination (see Chapters 2, 3, and 4;
          research on sensitive subpopulations should also be incorporated into this need [see
          Chapter 5]);
       •  Ability  to  discriminate  between  human  and   nonhuman   sources   of  fecal
          contamination;
       •  Information on  sources of  runoff  (e.g.,  concentrated animal  feeding operations
          [CAFOs]) from both marine and fresh recreational waters;
       •  How much water are bathers ingesting while swimming?; and
       •  Fate  and transport of indicators (and pathogens) in the aquatic environment.

Workgroup members also identified the following possible long-term research needs:

       •  Comparison of prospective  cohort  and randomized control trial  epidemiological
          studies;
       •  Identification of pathogens (viruses, bacteria, or parasites) responsible for GI illnesses
          at bathing beaches;
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       •  Health impacts following exposures over multiple days;
       •  Significance of non-GI illnesses (dermal, aural, nasal); and
       •  Comparison  of  severity of illnesses  related to exposure  to  human and  animal
          (domestic and wildlife) fecal contamination (see Chapter 4).

Although  workgroup members  identified these  long-term  research needs  there were some
differences of expert opinion on the essentiality of these  needs.  In  conjunction with these
research needs,  workgroup members  also noted the  necessity to clarify  the  objectives of
environmental health assessments  (sanitary investigations) and  microbial source tracking
methods.

5.     Is a "toolbox" approach appropriate for developing new or revised recreational criteria
       in the near-term? Why or why not?

The Approaches  to  Criteria  Development workgroup  members interpreted the  concept of a
toolbox approach differently.  Some members believed that  shifting from the current (US EPA,
1986) criteria approach to either the WHO (2003) or EU (EP/CEU, 2006) model approach would
constitute a type of toolbox approach. For example, the sanitary investigation as used within the
WHO approach could be considered to be an additional tool in the implementation of the new or
revised criteria.  Others believed the toolbox approach meant the use of alternative or additional
fecal indicators or pathogen methods. In either case, the implementation  of the toolbox approach
was dependent upon  additional epidemiological studies being conducted that may or may not be
possible within the near-term (2.5 to 3 years).

Predictive models could  be an integral part of the toolbox. Models that have been both validated
and calibrated are critical  for  accurately predicting recreational  waters that exceed criteria.
Improved notification via forecasting models is likely to protect public heath better then  the use
of single sample criteria based on current indicators measured by culture methods.

6.     What are the pros and cons of selecting a "toolbox" approach?

There was commonality  of workgroup member opinions in  regards to  several of the pros and
cons related to the use of a toolbox approach.

Most of the workgroup members believed that a toolbox approach would help address some of
the issues with geographic variability.  For example, the use of different  fecal indicators that
demonstrate improved indicator/illness rate relationships in subtropical or tropical waters would
reduce the likelihood of these waters inappropriately being listed as impaired under the CWA.
The use of some form of sanitary investigations,  as within the WHO (2003) approach, would
potentially allow for discounting those waters that were identified  as having limited or no
anthropogenic  fecal  loading,  thereby  avoiding those  waters   being  listed  as  impaired
inappropriately.
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The cons associated with a toolbox approach were primarily related to the current lack of data on
the fecal indicator/illness rate relationships for additional methods. There was also some concern
expressed about the difficulty in incorporating the toolbox approach to account for the use of
different indicators for different CWA  §304(a)  needs.  There was also  concern about the
feasibility of establishing requisite and defensible linkages between the various indicator/method
combinations that could comprise the toolbox.

7.     What are the desired features or characteristics that would make a "toolbox" approach
       appropriate?

Any additional fecal indicator  or pathogen measure within the toolbox would need to have
proven indicator/illness rate relationships, or at a minimum, have a linkage to another indicator
that does.  The characteristic of being interrelated (correlated) with each  other would be of
particular use, especially if one was going to be used to support one aspect of the CWA §304(a)
needs and the other was being used to support another §304(a) need.

The toolbox approach should support more then just one aspect of the CWA §304(a) needs. Any
of the tools  within the toolbox should be  validated,  either by predictive  modeling  or  by
correlation to other tools within the toolbox. Additionally, if a management action is initiated on
the results of a particular tool within the toolbox (e.g., a beach closure based on qPCR) the
follow up action should also be based upon the same tool (beach opened based on qPCR), to the
extent possible.

8.     Would a "toolbox" approach achieve additional public health protection as compared
       to another approach? Why or why not?

Yes, as mentioned above, the additional tools within the toolbox could  potentially improve the
assessment of waters (e.g., reduce the listing of tropical or subtropical waters as impaired due to
the poor indicator/illness relationship for these waters) or  the appropriateness of beach advisories
or closures.

9.     Criteria for secondary contact  recreation could  be part  of a  "toolbox."   What
       approaches would be  appropriate for developing  criteria for  secondary contact
       recreation?

Workgroup  members defined  secondary contact as  limited or incidental  contact.   As such,
workgroup members believed that the  same approach could be used for waters designated as
secondary contact as used for primary contact, meaning that epidemiologically-based health data
could be used to  define acceptable exposure limits.  QMRA could  also be used  for these
purposes to supplement available epidemiological information.
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10.    What are critical research and science needs in developing or selecting an appropriate
       approach for secondary contact recreation?

Additional epidemiological studies may be needed under secondary  contact conditions. These
epidemiological studies should address  the same data needs as those  proposed in support of the
primary recreation criteria. Alternatively, QMRA could be used if exposure data are available.

       Can this research be completed in time to be used in criteria development in the near-
       term?

It  is possible,  but unlikely given the current demands for additional epidemiological  work in
support of the primary contact designated use.  However, a QMRA study could be conducted
during this timeframe.

11.    What are the implementation  considerations of the different approaches for CWA
       purposes (1) beach monitoring and notification,  (2) development of NPDES permits,
       (3) assessments to determine use attainment, and (4) development of TMDLs?

All three  approaches—the  (EPA) 1986  criteria, EU  (EP/CEU, 2006), and  WHO  (2003)
approaches—would require additional epidemiological studies to implement.  Given additional
epidemiological  data with  additional  indicators, it  is  possible that each approach  could
potentially be  implemented and could support multiple CWA §304(a) needs.  As noted above,
using multiple indicators for different purposes is a cause of concern.

       Are there practical considerations that could preclude, or greatly limit, the use of an
       approach in routine, regulatory implementation (e.g., field sampling issues, laboratory
       challenges, staff training, etc.)?

If future epidemiological studies do not  identify additional indicator tools that would improve the
indicator/illness relationship for a broader geographic range, the (EPA) 1986  model would be a
much less desirable option than either the WHO (2003) or EU (EP/CEU, 2006) approach. Both
the EU  and  WHO approaches  apply a discounting scheme, so  the  failure  of near-term
epidemiological  studies  to  identify  more   robust  indicator  tools does   not preclude  the
implementation of these approaches for the development of new  or revised  recreational water
quality criteria.

Geographic Applicability

1.      Is a single criterion available that is  appropriate for the  diverse  range of geographic
       conditions?  Why or why not?

No.   Different regions of the  country  have different potentials  for regrowth,  persistence,
indicator/pathogen die off rates  (UV exposure), and  indicator/illness rate relationships.  The
literature  supports the conclusion that additional indicators  will be necessary to accurately
identify those  recreational waters that are at risk across  all geographic regions of the  country.
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Workgroup members felt that future epidemiological studies should include additional indicators
to improve the indicator/illness relationship across all geographic areas of the United States.

2.     Is a toolbox approach appropriate for different geographical conditions?  Why or why
       not?

Yes, for the reasons noted in the response to Question #1 above.

3.     What would a "toolbox" that addresses geographical differences look like?

The toolbox might  include  alternative or additional  indicators that better  predict, either
individually or in combination, the indicator/illness relationship.  Alternatively,  the  toolbox
might include environmental  health and safety assessments (sanitary investigations) that allow
for  the discounting of waters that appear as impaired based upon the indicator results, but for
which the impairment judgments are not supported by demonstrable impacts (elevated indicators
from wildlife or sediment sources only).  The toolbox approach also could be used to allow
different indicators and be used for different CWA §304(a) purposes.

4.     What are critical research and science needs in developing or selecting an approach
       that will appropriately factor-in diverse geographical conditions?

Additional epidemiological  studies are needed that  provide improved indicator/illness  rate
relationships  for all  regions  of the United  States.   These additional  epidemiological studies
should focus on recreational waters that are under a variety of potential pathogen sources (e.g.,
sewage, urban runoff, non-point sources, non-anthropogenic sources).  Where  possible,  the
various potential  sources of pathogens  should be  considered within  a single  epidemiological
study rather than each being considered in separate studies.  This might be possible by examining
waters that have varying sources depending upon rainfall or climatic conditions. For example,
California beaches that have  urban runoff sources during  wet weather but no known point or
non-point sources during dry weather.

To  pursue the 2003 WHO approach, a quantitative environmental health and safety assessment
(i.e.,  sanitary investigation)  tool  would  have  to be developed  in  order  to   support  the
categorization of recreational waters as to their risk of potential fecal contamination.   To have
greater confidence in the WHO model, research  is needed to determine if the notion that fecal
contamination from non-anthropogenic sources is of lesser human health risk that anthropogenic
sources.

Expression of Criteria

1.     Given the diverse needs of the CWA programs and the overarching goal of protecting
       and restoring waters for swimming, what protection  is provided by establishing a 30-
       day "average" value as the criteria?

There was some commonality of workgroup member opinion on this issue. Several members
felt that the criteria would best be expressed as a  geometric mean and/or a standard deviation or
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95th percentile.   Several members believed that these values would have to be site specific in
order to be protective.  If formatted correctly, an average value is as protective as any other
single measure.

       What additional protection (if any) is provided by a daily or instantaneous maximum
       value?

The added  value provided  by an  instantaneous maximum  value  is dependent  upon  the
indicator/illness rate  association.  Short-term variability associated with the current indicators
limit the usefulness  of single sample maximum values; however, using qPCR  or  other non
culture-based  methods may  improve  the  utility  of single  sample values.    Additional
epidemiological data is needed to assist in making this determination.  One problem  is that the
formulation  of the current single sample maximum is  such that it is  more stringent than the
geometric mean, and this has caused substantial confusion among States.

       From a scientific standpoint, is  one measure better scientifically than another for
       particular purposes  (e.g., mean value for purposes of identifying waters  and daily
       maximum for beach monitoring and notification purposes) ? Why ?

It depends on how the new or revised criteria are derived and the assumptions made about the
variability in water quality.  There is some scientific merit to the continued use of single sample
maximum values for some CWA purposes.  This is of particular interest with respect to public
health  protection; however,  there was not agreement among the workgroup members on this
point.

2.      What are pros and cons of expressing the  criteria differently for the various  CWA
       program needs?

As  currently used,  single sample maximum values are not effective for beach monitoring
purposes.  This may  change somewhat if the shift from culture-based methods to non culture-
based methods improves the issues with variability and indicator/illness rate relationships.

There  is potential to  use single values, whether  culture- or non-culture based,  in  predictive
models for beach monitoring. The geometric mean, standard deviation, or 95th percentiles show
promise for multiple CWA programs.  So long as there is data from epidemiological studies that
demonstrates the one expression of the criteria is equally as protective as another, there would be
no problem with using different expressions of the criteria for different CWA purposes.

3.      What are  the implications  of  instantaneous or daily  values for  public  health
       protection? If we don't  currently have a good understanding of this,  what are the
       critical research and science needs to answer the questions?

Currently there is very little data to support the use of instantaneous or daily values derived from
culture-based methods from Day  1 to predict the need to post or close recreational waters on Day
2.   There are recent epidemiological  data (Wade et al., 2006)  that indicates that qPCR (non
culture)-based indicator methods may be effective for same day notification at some beaches.
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Group members identified several critical research needs that would potential improve the utility
of an instantaneous or daily value (see Chapter 1).

4.     If EPA were to set criteria at a mean concentration over 30 days and not recommend a
      single sample maximum, do we understand the illnesses that could occur on a single
      day (where the level would still lead to compliance with the 30-day average) ?

In general, workgroup members agreed that the probability of illness on any  single day is not
understood.  Some reasons for this are as follows:

      •  the variance in water quality  in any particular water body could be  significantly
          different than the criteria from which it was derived;
      •  the variability of indicator could change between beaches and temporally; and
      •  if the exposure-response curve is based on a geometric mean, the interpretation of a
          single sample is difficult.

With research, a single sample maximum could be used to estimate the probability of illness on a
particular day.

5.     If the science is "not there," what are the critical research and science needs to answer
      this question?

Critical  research and science needs centered  on expanding epidemiological  studies  based  on
qPCR (and other indicators and methods) to other situations (e.g., example marine beaches or
non-point pollution sources).

6.      What are the implementation considerations for CWA purposes of failing to address
      (and addressing) differences geographically in the criteria and failing to include (and
      including) a single sample maximum value for (1) beach monitoring and notification,
      (2) development of NPDES permits, (3)  assessments to determine  use attainment, and
      (4) development ofTMDLs? Are there practical considerations that could preclude, or
      greatly limit, the  usage in routine, regulatory implementation (e.g., field  sampling
      issues, laboratory challenges, staff training, etc.)?

To  address this question  it was separated into the following two components:  (1)  failing to
address  geographical differences, and (2) failing to include a single sample maximum for various
purposes identified in the CWA.

      (1) Failure to recognize that the current criteria may not be  applicable to tropical and
          subtropical beaches could present an unacceptable risk to bathers in these recreational
          waters.
      (2) Single sample maximum NPDES permits - compliance tools such as NPDES permits
          require single sample maximums and need to continue that  approach.

Regarding States' designated use attainment, single sample maximum values are not necessarily
required and in fact  may  not be necessary.  These types of criteria  could be useful for beach
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monitoring and water quality notification. Regarding TMDLs, single sample maximum values
do not seem applicable for TMDLs for indicator bacteria.

1.6    Concluding Remarks

The workgroup members did not specifically prefer one criteria approach over another primarily
because it  is believed that additional data  that will become available from epidemiological
studies within the next 2 to 3 years and how those data will inform the  criteria development
process is not yet known. For example, it is not known what new information will be available
based on new indicators and/or methods and how that  information might inform a sanitary
investigation component of a WHO-based criteria approach.

Further, it was the opinion of workgroup members that there may be differences in the ability to
implement  each of the three approaches if all of the various criteria attributes are not met.  For
example, workgroup members felt that the 1986 EPA approach with a new or different indicator
and/or method would not be satisfactory if most or all of the criteria attributes  were not met.
Workgroup members also felt that the same set of circumstances may not preclude the use of the
WHO or EU approach.  With respect to the use of a toolbox-based approach where different
indicators are  used for different CWA §304(a) applications, workgroup members expressed
concern about the feasibility of developing health-based linkages (as  described above) as would
be required by either the WHO or EU approaches. Thus, at this time, no workgroup member was
definitively able to recommend one approach over another; however, the  workgroup members
agreed that the choice of approaches must be deferred pending the outcome of ongoing and near-
term research.

References

EP/CEU (European Parliament/Council  of the European Union). 2006. Directive 2006/7/EC of
the European Parliament and of the Council of 15 February 2006 Concerning the Management of
Bathing Water Quality and  Repealing Directive 76/160/EEC. Official Journal of the European
Union L64: 31-51. Available at:
http://europa.eu.int/eurlex/lex/LexUriServ/site/en/oj/2006/l_064/l_06420060304en00370051.pdf

Fleisher, JM; Kay, D; Salmon, RL;  Jones, F; Wyer, MD; Godfree, AF.  1996. Marine waters
contaminated with domestic sewage: Nonenteric illnesses associated with bather exposure in the
United Kingdom. American Journal of Public Health 86: 1228-1234.

Kay, D; Fleisher, JM; Salmon, RL; Jones, F; Wyer, MD; Godfree, AF; Zelenauch-Jacquotte, Z;
Shore, R. 1994. Predicting  the likelihood of gastroenteritis from sea bathing - Results  from
randomized exposure. The Lancet 344: 905-909.

Kay, D; Bartram, J; Priiss, A; Ashbolt, N; Wyer, MD; Fleisher, D; Fewtrell, L; Rogers, A; Rees,
G.  2004. Derivation of numerical values for the World Health Organization  guidelines  for
recreational waters. Water Research 38(3): 1296-1304.
MNHW (Minister of National Health and Welfare). 1992. Guidelines for Canadian Recreational
Water Quality. Ottawa, Canada: MNHW.
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Priiss,  A.  1998.  Review of  epidemiological studies  on health effects  from exposure  to
recreational water. InternationalJournal of Epidemiology 27(1): 1-9.

US EPA (U.S. Environmental Protection Agency).  1983. Health Effects Criteria for Marine
Recreational Waters. EPA-600/1-80-031. Cincinnati, OH: US EPA.

US EPA. 1984. Health Effects Criteria for Fresh  Recreational Waters.  EPA-600-1-84-004.
Cincinnati, OH: US EPA.

US  EPA.  1986.  Ambient Water Quality Criteria for Bacteria -  1986.  EPA440/5-84-002.
Washington, DC: US EPA.

US EPA. (2004) Water Quality Standards for Coastal and Great Lakes Recreation Waters Final
Rule. Federal Register 69(220): 67217-67243.

US EPA 2006. Water Quality Standards for Coastal Recreation Waters:  Using Single Sample
Maximum Values in State Water Quality Standards.  EPA-823-F-06-013. Washington, DC: US
EPA.

Wade, TJ;  Calderon, RL; Sams, E; Beach, M; Brenner,  KP; Williams, AH; Dufour,  AP. 2006.
Rapidly measured indicators of recreational water quality are predictive of swimming-associated
gastrointestinal illness. Environmental Health Perspectives 114(1): 24-28.

WHO  (World  Health Organization).  1999. Health Based Monitoring of Recreational Waters:
The Feasibility of a New Approach  (The  "Annapolis Protocol").  Organization Report No.
WHO/SDE/WSH/99.1. Geneva, Switzerland: WHO.

WHO. 2003. Guidelines for  Safe Recreational Water Environments.  Volume 1 Coastal and
Fresh Waters. Geneva, Switzerland: WHO.

Wiedenmann,  A;  Kruger, P; Dietz, K; Lopez-Pila,  JM; Szewzyk, R; Botzenhart, K. 2006.  A
randomized controlled trial assessing  infectious disease risks from bathing in fresh recreational
waters in relation to the concentration of Escherichia coli, intestinal enterococci, Clostridium
perfringens, and somatic coliphages. Environmental Health Perspectives 114(2): 228-236.

Wyer,  D; Kay, D; Fleisher, JM. 1999. An experimental health-related classification for marine
waters. Water Research 33(3): 715-722.
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                              CHAPTER 2
              PATHOGENS, PATHOGEN INDICATORS, AND
               INDICATORS OF FECAL CONTAMINATION
              Nicholas Ashbolt, Chair, USEPA
              Roger Fujioka, University of Hawaii, Manoa
              Toni Glymph, Wisconsin Department of Natural Resources
              Charles McGee, Orange County Sanitation District, California
              Stephen Schaub, USEPA
              Mark Sobsey, University of North Carolina, Chapel Hill
              Gary Toranzos, University of Puerto Rico, Rio Piedras
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2.1    Application of Microbial/Biomarker Parameters

The charge of the  Pathogen, Pathogen  Indicators,  and Indicators  of Fecal Contamination
workgroup was to identify critical research and science needs in the development of new or
revised criteria  for  recreational  waters,  including  total  maximum  daily  load  (TMDL)
implementation, and National Pollutant Discharge Elimination System (NPDES) implementation
using microbial and chemical indicators. The discussions were limited to constituents for which
methods are currently available or expected to be available within the next 3 years and focused
around the following four issues:

    1.  Fecal matter indicators (as surrogates for gastrointestinal [GI] and non-GI illnesses);
    2.  Pathogens and their index organisms (GI and non-GI illnesses);
    3.  Application of fecal indicators, pathogen index organisms, and pathogens in combination
       for criteria development; and
    4.  Application of all the above for all categories of waters,  climatology, and geographical
       considerations.

Currently, implementation of ambient water quality criteria (AWQC)  for the four Clean Water
Act (CWA) applications require monitoring fecal bacterial  indicators to  assess the degree to
which the water is contaminated with sewage and sewage-borne pathogens with respect to the
accepted  risk for exposure.   Development  of the existing (US EPA, 1986)  AWQC  for
recreational waters were based on epidemiological studies that related concentrations of fecal
indicator bacteria at recreational waters impacted primarily by point sources of human sewage.

Since development of the currently  used  1986 AWQC, research  has shown  that this narrow
health effects-based  standard  (i.e.,  epidemiological  studies  at beaches with point sources of
human  sewage) is limited in that it does not take into account differences in geographical
conditions, ecology of microorganisms, and varying sources of fecal indicator bacteria.  In  this
regard, the expected relationship between illness and indicator organism densities would be high
if the source of contamination is human sewage, moderate if the source was a mixture of human
and animal feces, or lower if the source is the result of replication of the indicator bacteria in the
environment, such as in soil,  sediments, storm drains, or on plants  or aquatic vegetative matter.
Initially, replication  of fecal  indicator  bacteria was reported in tropical areas  (e.g.,  Hawaii,
Guam, Puerto Rico) but has now been documented in subtropical areas such as south Florida  and
even temperate areas (Great Lakes States). A further but untested complication in interpreting
fecal  indicator bacteria results may arise due to different rates of pathogen  inactivation in the
environment relative to fecal indicators across different geographic and climatic regions.

It is for the above reasons that experts in the field of microbial water quality generally agree that
the principles  of  microbial  ecology  must be  considered  in  water  quality  assessment.
Understanding and applying these principles requires an assessment of  the  sources of fecal
contamination, selection of the appropriate methods used to assess these sources, a connection
between the intended AWQC application, and the fecal and/or pathogen indicator or pathogen
measured  and an  analysis of that indicator's fate and transport.  Because of this understanding,
workgroup members suggested a tiered assessment of a watershed,  starting with traditional fecal
indicators  (conservative measures),  and  progressing to  select  a  suite  of  indicators  of
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contamination  (providing  source  specificity  and   contaminant  load  information).    A
characterization of contaminant inputs through a sanitary investigation of the watershed and the
waterbody being assessed  should be undertaken, specifically assessing hazardous events, such as
rainfall-induced runoff or wastewater treatment failure.  Key information would pertain to a
cataloguing of point sources (e.g., sewage effluent) and non-point sources (e.g., animals,  runoff,
on-site septic systems, environmental regrowth) so that a comparative risk assessment  can be
made based on the concentrations of standard (traditional) monitoring fecal indicators (i.e., E.
co//', enterococci) and the expected presence of human pathogens. This initial assessment should
assist in understanding the relationship between the contamination and epidemiological  studies
(indicator levels and risks of illness) mentioned elsewhere in these proceedings.  In order to
select appropriate indicators, a  tiered toolbox  approach was preferred by workgroup members
rather than promoting use of one particular indicator over another.

2.2    Tiered Toolbox Monitoring Approach

An initial cataloguing of fecal pollution sources should include a review of existing  monitoring
data and a sanitary investigation to assess contaminant levels and sources that impact a given
recreational  water site.   Based on that information, the indicator used in  monitoring or the
predictive modeling tool most appropriate for each  CWA AWQC application and contamination
source would be selected for the situation. Water quality assessment for each recreational water
site should begin with the simplest analyses and assessment and move on to the most appropriate
(specific or targeted)  indicator for that  site or purpose.  More refined tools  to differentiate
between  human,  domestic  animal,  or  environmental  sources of fecal contamination  could
subsequently be used if deemed  necessary.

If a sanitary investigation determines that fecal pollution is human or animal origin, then E. coli
or enterococci could be used in the tier one water  quality assessment because many pathogens
can be expected to multiply in human and animal intestines.  If the source of the "fecal"  indicator
organisms is determined to be from the environment (i.e., from growth in soil/sand, sediment, or
water), then E. coli and  enterococci may be inappropriate  because most pathogens are  not
capable of environmental multiplication.  As a result, the monitoring for this tier would need to
be a fecal organism/chemical  that does not amplify  in the environment, such as spores of
Clostridium perfringens or male-specific (F+) coliphages measured by culture- or  molecular-
based methods, specific members of the Bacteriodes bacteria  measured by a molecular method,
or use of a chemical indicator of fecal material.

For a subsequent tier of monitoring, infectivity and/or molecular methods  could be  used for
specific groups of pathogens such as, for bacterial pathogens (shiga-toxin producing E. coli
[STEC] or Salmonella), for protozoa (Cryptosporidium  or  Giardid), and  for representative
human sewage-borne viruses (enteroviruses, adenoviruses, polyomaviruses, or noroviruses).

Location-specific  data should be  archived for potential use in future predictive modeling that
might allow for management of site-specific fecal contaminants. Finally, if possible, archiving
samples for further characterization and national comparison of new indicators, and/or pathogens
and their respective methods would be advantageous assuming a national repository database and
sample archive facility could be established.
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Several non-GI illnesses have been associated with recreational uses of water but these are not
addressed by monitoring for fecal indicator microorganisms or chemicals because the etiological
agents for these waterborne diseases come from non-sewage  sources. Examples include animal
urine  {Leptospira spp.), shedding from human skin (Staphylococcus aureus\ or microorganisms
that are naturally present in freshwater environments (Aeromonas hydrophila, Naegleri fowler•/'/',
Legionella pneumophild).   Further, several human pathogenic Vibrio species (V. cholerae, V.
vulnificus, V. pamhaemolyticus,  V. alginolyticus) are indigenous to marine and brackish waters.
Because reliable  indicators  have not been developed  for non-GI etiological agents,  the best
approach to address aquatic non-enteric pathogens is to characterize the  aquatic conditions that
increase the risk for these  pathogens. For pathogenic Vibrio spp., this includes saline waters of
warmer temperature and waters that contain high levels of nutrients.

2.3    Parameters for Hazardous Event Pollution Monitoring

The first approach to  investigate  a hazardous event (sewage discharge, rainfall impact,  etc.)
would be to assay for fecal indicators (appropriate for a climatic/geographic area of concern, see
Section 2.4). The primary indicators of fecal contamination are E. coli or enterococci; however,
based  on the classification  from an initial  sanitary  investigation, alternatives may  include
Clostridium perfringens or F+  coliphages (dependent on a robust method being  confirmed).
These must be demonstrated to  relate  to  a possible health outcome (see  Section 2.4).  When
information is required on  source characterization, then  additional microbial  indicators (see
Section 2.5) are generally preferred over chemical biomarkers (see Section 2.7).

Focused sampling during and after higher risk periods  is important when information from the
sanitary investigation (which may include system models) is used to predict such risk. For these
applications, the context of the likely pathogen group(s) should dictate the type of indicator to
assay. For example, for rainfall  in an area possibly impacted by on-site  septic systems, viruses
are considered the most mobile pathogen group so use of virus model organisms, such as the F+
coliphages,  would be  informative.  For  sites contaminated by  concentrated animal  feeding
operations (CAFOs), reasonable pathogen index tests include shiga-toxin  producing E. coli or
Cryptosporidium.  This approach assumes that some background level of the  targeted  group is
known for the area of concern (see Section 2.8, research needs).

2.3.1   Microbiological Parameters

The Beaches Environmental  Assessment  and Coastal  Health (BEACH) Act  of 2000  requires
States with  coastal or  Great Lakes recreational  waters to adopt  the current  (US EPA, 1986)
criteria for E. coli and  enterococci. In November 2004, EPA promulgated a final rule that put
federal  standards in  place for the 21 coastal states that had not adopted the 1986 criteria or
established criteria as protective of human health as EPA's 1986 criteria.  However, these federal
criteria apply only to coastal states and Great Lakes waters.  In many cases,  a fecal coliform-
based standard still applies to many states having only inland waters. It is important to note that
the results of the epidemiological studies used to generate the 1986 criteria  for  coastal and Great
Lakes waters may not be directly applicable to all inland waters.
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2.4    Traditional Fecal Indicators (Coliforms and Enterococci)

Consideration of the environmental  context for which these traditional indicators are used is
critical to the interpretation of the results.  For example, wastewater treatment/disinfection may
be  effective  in  reducing the  number  of these  traditional fecal  indicators  but ineffective in
reducing/inactivating some pathogens  of concern (Blatchley et  al.,  2007).   Some industrial
treatment systems may contain/enable replication of high number of "fecal indicators," which are
not necessarily associated with fecal sources (Degnan, 2007; Gauthier and Archibald, 2001).
Ambient  water  and soils  in tropical  environments  may  be conducive to  the  growth  of
environmental strains of E. coli and enterococci  (Fujioka and Byappanahalli, 2001).  A similar
situation was found in temperate Australian waters (Ashbolt et al., 1997; Barnes and Gordon,
2004; Davies et al.,  1995)  and these indicators have also been found to persist in U.S. beach
sand/sediments (Whitman et al., 2006).

The range of strains of fecal indicators identified by traditional culture-based methods may differ
from  those  identified by enzyme-based  and quantitative polymerase  chain  reaction  (qPCR
[molecular])-based methods.   Further, the strains more associated with  fecal matter are not
differentiated from the environmental strains by  all of these methods. There are commercially
available systems that can  aid in the discrimination of strains; however, less expensive typing
kits do not accurately provide such discrimination for environmental strains.  It is important to
note then when quantifying fecal indicator organisms, different methods target different strains.
For example, cells stressed by wastewater disinfection processes may be enumerated using MPN
(Most Probable Number) methods but excluded by methods enumerated by colony forming unit
(cfu)  methods.   When current qPCR methods are used, both viable and non-viable cells are
detected.  In addition, the number of gene targets may vary per cell and therefore do not provide
comparable information to culture-based results.

    E. coli

Of the traditional fecal indicators (see  also Appendix E, Text Box E-l), only E. coli has  been
shown in epidemiological  studies to  consistently relate to health  outcomes for freshwater
recreational water users (Cabelli et al., 1982;  Wade et al., 2003; Wiedenmann et al.,  2006).  In
marine/estuarine waters,  E. coli is more  readily inactivated than enterococci  and appears to
correlate less well to health  risk than enterococci for saline water environments.

Subtyping of different strains of E. coli (library-dependent microbial  source tracking methods)
appears to be very site-specific if useful at all. Thus, it is not generally suggested as an effective
way forward to separate  environmental sources of E. coli from  fecal sources across the United
States (see Section 2.5).

    Enterococci

The enterococci  are the major group of fecal  indicators that have a clear link to GI illness and
upper respiratory disease in bathers in marine and fresh recreational waters (Kay et al., 2004).
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 There are, however, several shortcomings in the use of current methods for enterococci.  Most
 importantly, there is a range of different Enterococcus spp. detected by current methods.  Based
 on unpublished Californian studies  (Stephen  Weisberg, SCCWRP,  personal  communication,
 2007), greater  fecal specificity may result from specific identification and enumeration of E.
faecalis or E. faecium or molecular-based methods targeting specific genes within these species
 (e.g., ribosomal RNA or enterococcal cell surface-associated protein and its gene Esp) (Lehner et
 al., 2005;  Liu  et al., 2006).  However, no robust method is currently  available that readily
 provides such information, nor has this concept been verified at other U.S.  recreational water
 sites (Anderson et al., 1997).

 2.5    Alternative Fecal Indicators

 2.5.1  Bacteria

    Clostridium perfringens

 C. perfringens  is a  member of the sulphite-reducing clostridia (SRC), which are  spore-forming
 anaerobic bacteria excreted in human  and animal fecal matter, but unlike other SRC, do not
 appear to grow in the aquatic/soil environment.  These bacteria have been used as  fecal indicator
 organisms for decades.  Australian and North  Carolina studies show C. perfringens levels  in
 humans comparable to levels found in dog and feral pig feces, but low levels in cattle, sheep,
 horses, and birds (Leeming et al., 1998; Mark Sobsey, University of North Carolina, Chapel Hill,
 personal communication, 2007).  Importantly, because C. perfringens does not appear to grow in
 aquatic/soil environments,  it has potential to be  useful as  a  fecal  indicator for tropical
 environments such as in Hawaii  where growth  of E. coll and enterococci in soil/sand, sediment,
 and water make those indicator organisms less useful (Byappanahalli and Fujioka,  1998; Hardina
 and Fujioka, 1991;  Roll  and Fujioka,  1997).   For example, in  ambient streams in Hawaii,
 concentrations of fecal  coliforms, E. coli, and enterococci consistently exceed recreational Water
 Quality Standards due to  contribution by extra enteric sources (Hardina and Fujioka,  1991,
 Luther and Fujioka, 2004).  Thus,  monitoring inland and coastal waters for C. perfringens
 provides reliable data for sewage contamination and is used by the Hawaii State Department  of
 Health to confirm a sewage contamination event (Fujioka and Byappanahalli, 2001).

 The presence of C. perfringens (spores)  in  water,  therefore  provides  evidence  of existing
 human/urban  fecal  contamination,  which may   reflect  either  recent or  historical  fecal
 contamination from humans or animals.  Although methods have been available for some time,
 confirmation of a robust and consistent method approach should be developed. For example, the
 advantages of heat-treating samples (or not) to remove background vegetative cells and induce
 spore germination remains unclear.

 The environmental resistance of C. perfringens spores has both advantages and disadvantages  in
 their application as a  fecal indicator,  pathogen indicator,  and as an indicator  of wastewater
 treatment efficacy.  Collectively, these make C. perfringens spores better indicators of persistent
 and treatment-resistant pathogens, such as Cryptosporidium oocysts (resistance to chlorine) and
 adenoviruses (resistant to UV radiation).  However, they can be so persistent in the environment
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that they may not indicate the presence of pathogens coming from recent (contemporary) fecal
contamination.

Recent  studies  on the partitioning of C. perfringens  and other  fecal indicator microbes  in
environmental waters, such as E. coli and coliphages, indicate differences in the extent of their
association with settleable particulate matter (Characklis et al., 2005; Krometis et al., 2007).  To
date, limited data  have been collected on any potential relationship between C. perfringens
counts and recreator health outcomes (see Section 2.8).

    Bacteroides

Bacteroides spp. are members of the normal microbiota of warm blooded animals and studies
have shown them  to be  among  the most prevalent genera in feces (Holdeman et al.,  1976).
Because they are strict anaerobes that grow in the GI tract of humans and animals, they do not
survive  for long periods of time under aerobic conditions (Kreader et al., 1998).  However, their
survival under  different redox potential conditions  (e.g., sediments) has not been  thoroughly
studied. Recent research based on  molecular methods has demonstrated that some isolates may
be  strictly associated with human feces  (Walters  et al., 2007).  If this  is the case,  these
microorganisms also  have the  potential  to be used  for microbial source tracking (MST)
applications.

Studies  have indicated human versus bovine specificity in certain 16S  rRNA genes therefore,
16S rRNA Bacteroides genes have been used as an index of human or animal contamination in
Europe  and the  United States. The ability to differentiate sources of fecal contamination is very
attractive when  it comes to determining risk as a result of exposure via recreational waters.  The
molecular methodology has been shown to be robust and applicable in the United States and
Europe, though it remains to be seen if this robustness holds across temperate versus tropical or
subtropical zones  of the world.    Some results from Hawaii and Europe indicate that these
methods may be useful under those climatic conditions (Betancourt and Fujioka, 2006;  Seurinck
et al., 2006).  Either way,  it is  unclear whether quantification of human/animal fecal loads will be
consistent or indeed possible using these molecular-based methods.

Though data from molecular techniques have shown that there is specificity in the human versus
animal  strains,  the fact that  both  human and  animal  feces  contain a diverse population  of
Bacteroides spp. may limit the usefulness of some detection methods.   Methods that  focus on
one target may have reduced sensitivity  as a result  of the lower concentrations  of a specific
Bacteroides strain.  Data  have shown that Bacteroides spp. does not survive for long periods of
time in the environment; thus, Bacteroides detected by qPCR in ambient waters includes a high
percentage of inactivated microorganisms.  The  fact that qPCR detects both live and dead
organisms  needs to be considered  when  data are applied  in different contexts (e.g.,  different
AWQC applications).  That is, qPCR detection is linked to the time the nucleic acid remains
within the cell  without being degraded.  EPA data  have demonstrated  that the DNA remains
undegraded for up to 20  days (Kevin  Oshima, USEPA,  Office of Research and Development,
personal communication,  2007) in the  inactivated unlysed cells.  This may be equivalent to the
survival of some enteric pathogens under environmental  conditions.   Thus,  the presence  of
Bacteroides may have possible use as an indicator of health effects. Because the concentration
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of Bacteroides spp. in feces is much higher than other fecal bacteria,  once the persistence  of
PCR-detected types is better understood, it may also be useful for TMDL applications, although
this possibility needs further evaluation.

The molecular methodology for the detection of general and human-specific Bacteroides spp. is
already being tested and has proven to be robust (Gawler et al., 2007; Walters et al., 2007).
Thus, if detection methods are validated in the United States there is an excellent opportunity for
short-term advances in quickly  adapting the use of this alternate indicator for the rapid analyses
of recreational waters and fecal  source identification.

2.5.2   Bacteriophages

    Coliphages

Bacteriophages (viruses) that infect E. coli and possibly other closely related coliform bacteria
are called coliphages.   There is a long history  of research  documenting the possible  uses  of
phages  as  indicators of fecal  contamination (Grabow et al.,  1998).  Coliphages were  first
proposed as indicators of the presence of E.  coli bacteria  and are taxonomically very diverse,
covering the following six virus  families:   three families  of double-stranded DNA  viruses
(Myoviridae,  Styloviriae,  Podoviridae\  two   families  of  single-stranded  DNA  phages
{Microviridae and Inoviridae), and one family of single-stranded RNA viruses {Leviviridae).

Coliphages that infect via the host cell wall of E. coli are  called somatic coliphages (including
families Myoviridae, Styloviriae, Podoviridae, and Microviridae). Male-specific (also called F+)
coliphages {Inoviridae  and Leviviridae) infect by  attaching to hair-like appendages called F-pili
protruding from the host bacterium surface.

Somatic phages have been explored as fecal, treatment efficacy, and health effects indicators.
However, little is known about the  specificity of their occurrence in human or animal feces.
Furthermore,  their considerable taxonomic  diversity  and the  lack  of readily available and
convenient methods to  distinguish or specifically detect the different groups has made it difficult
to determine which, if any, are effective fecal, treatment efficacy, or health effects indicators.  In
a recent study by Colford et al. (2007), somatic coliphages were not predictive of human health
risks from bathing in marine recreational water largely impacted by non-point sources of fecal
contamination. Furthermore, there is very little information  on the sources and ecology of the
somatic coliphages, especially for the different taxonomic groups. With rare exceptions, they are
detected as a broad group with no effort to identify specific  taxonomic groups or relate  or
attribute these different taxonomic  groups  to  specific  sources of human or animal  fecal
contamination or possibly non-fecal environmental sources.

Male-specific  coliphages  have  been  studied   extensively  as  fecal  indicators  and  for
water/wastewater treatment/disinfection efficacy.   Furthermore, F+  RNA coliphages  can be
distinguished   genetically   (via  nucleic   acid   detection   methods)  or  antigenically   (via
immunological methods), into four distinct subgroups:  I,  II, III, and IV.  There is reasonably
good evidence that Groups II and III are associated primarily with human fecal waste and that
Groups I and IV are associated primarily with animal fecal waste (Furuse et al., 1975; Hsu et al.,
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1995; Osawa et al., 1981) in the United States.  Male-specific coliphages have been included in
some epidemiological studies of recreational water.  In the recent study by  Colford et al. (2007)
at a marine recreational water site impacted primarily by non-point source fecal contamination,
F+  coliphages were  the only microbial indicator whose levels were associated with risks of
swimming-associated illness.

    Strengths of Coliphages as Indicators

Advantages of both somatic  and F+ coliphages as fecal indicators  include  their (1) presence in
relatively  high  concentrations in  sewage;  (2) relatively high persistence through wastewater
treatment  plants,  compared  to  typical bacterial indicators like E.  coli  and fecal coliforms
(coliphages may behave similarly to human viruses during wastewater treatment); and (3) ability
to be  detected in relatively small (100  mL)  to  medium  (1,000  mL)  volumes  of fecally
contaminated water.

Coliphages can be detected by relatively simple, affordable, and robust culture methods—several
of which have been standardized and collaboratively tested as EPA, EU, and ISO (International
Organization  for Standardization) water methods. However, the EPA methods for somatic and
F+ coliphages have been fully validated only for groundwater and not for ambient surface waters
or wastewaters. Recent research also describes a rapid, simple, and affordable method to detect
and group infectious F+ coliphages by short-term (3-hour) enrichment culture, followed by quick
(<1 minute) detection of positive cultures by a simple immunological (particle agglutination)
method scored by  simple visual  examination (Love and Sobsey,  2007).  The  method can be
conducted in an MPN format to quantify concentrations of the different F+ coliphage groups (F+
DNA and F+ RNA Groups I, II, III, and IV).

These findings indicate that robust, simple, rapid, and low-cost F+  coliphage methods could be
implemented  within the 2 to 3 year time frame if correlations to health targets are observed in
epidemiological studies.  It  would be valuable if water samples from  upcoming EPA and
SCCWRP (Southern California Coastal Water Research Project; see also  Appendix F) marine
recreational water  epidemiological studies are  collected and archived for analysis by  these
emerging qPCR methods once they are fully developed and validated.  In addition, research is
suggested to compare the performance of methods  for rapid coliphage detection by short-term
enrichment-particle agglutination and qPCR and to consider the advantages  and disadvantages of
these two methods for application to recreational water quality monitoring.

    Limitations of Coliphages as Indictors

Although effective methods are available to recover, detect, and quantify coliphages, limitations
and unsolved problems with these methods remain.  The single agar layer method (EPA Method
1601) for enumeration of coliphages by counting plaques is limited to sample volumes of about
100 mL. Analyzing  larger volumes is cumbersome and consumes  considerable materials, such
as Petri plates.  Although the enrichment culture-spot plate method can be  used to  conveniently
analyze sample volumes of up to  1 L, the  method makes it more difficult to resolve coliphage
mixtures when more than one type of coliphage is  present in the enriched sample volume.  In
some cases, one coliphage will grow faster and to a higher concentration. This makes it difficult
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to detect and isolate minority coliphages that grow more slowly and to lower concentrations.
However, detection of all of the different coliphages present as a mixture in enriched sample is
possible by either nucleic acid or immunological (particle immunoagglutination) methods.

The ecology of both somatic and F+ coliphages  remains poorly documented and inadequately
understood.  Information is lacking on bacterial  host range, sources, occurrence, and behavior
(survival, transport,  and  fate)  in different geographical regions having different climates
(temperate, subtropical, and  tropical) and  in waters  and wastewaters of different microbial
quality.

F+ coliphages can also be detected by  molecular-based methods, including conventional and
qPCR methods, according to recent studies.  Careful review of these studies suggests that there
may be deficiencies in the ability of these qPCR  methods to detect the broad range of F+ DNA
and F+ RNA  coliphages and their subgroups.   Nevertheless,  research is  now  in progress to
further improve F+ RNA  qPCR by developing and performance-validating primer sets for all
four genogroups  of F+ RNA coliphages (Stephanie Friedman, EPA  Environmental Effects
Research Laboratory Laboratory, personal communication, 2007).  Reliable methods have not
been  developed for  genetic analysis  and characterization  of different  somatic  coliphage
taxonomic groups.

Very few studies have been conducted to  evaluate F+ coliphages as predictive indicators of
human health risks from recreational use of water.  The most extensive study was conducted by
Colford et al.  (2007).  That study  showed no health relationship for somatic coliphages, but a
weak relationship for F+ coliphages examined by  two different assay methods—an MPN version
of EPA Method 1601 (enrichment-spot plate method) and EPA Method 1602 (saline agar layer
plaque assay).  However, these methods have not been  performance characterized and fully
validated for use in fresh and marine recreational waters according to EPA collaborative study
protocols. Additional studies of this type are needed to clarify their potential criteria uses.

   Bacteroides phages

Bacteroides phages, viruses that  specifically infect Bacteroides  spp., have been tested  as
indicators of fecal material in Spain and more recently in the U.K.  The former used a method
(bacterial host) that was tested in  some labs in the United States but further efforts were not
made as a result of the perceived difficulty in dealing with anaerobic methodology. Attempts to
use the B. fragilis strain VPI 3625  showed low occurrence of these phages  in the United States
(Chung and Sobsey, 1993). Spanish data initially supported the use of B. fragilis HSP40, which
is specific to phages that only occur in human feces. More recent British work indicated human
specificity and high phage counts for a newer Spanish host Bacteroides (GB-124), thus providing
the opportunity for determining human fecal contamination and virus transport using a rapid and
inexpensive phage method (Ebdon et al., 2007).

   Strengths of Bacteroides Phages as Indicators

The methods for the detection of Bacteroides spp. phages are inexpensive and their presence
indicates human fecal contamination.   In addition,  there is research that indicates specific
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Bacteroides hosts are susceptible to phages that are possibly useful for MST, which would be
beneficial for its use for CWA §304(a) criteria (Chung and Sobsey, 1993; Ebdon et al., 2007).

    Limitations of Bacteroides Phages as Indicators

The diversity of phages  including their specificity for human host strains is not yet well
characterized over a range of locations.  This type of data could be  easily obtained in 2 to 3
years, but if it is discovered that there is wide variability in their validity for MST, then their
attractiveness for use in national AWQC would be reduced.  Many laboratory personnel may not
have the experience required to work with anaerobic microorganisms; however, little additional
laboratory equipment would be required.  Because detection methods have not been standardized
in the United States, it would likely take several years to develop standardized methods for
enumeration of Bacteroides phages in water samples.

2.5.3   EU Project Summary of Tracers

Several  microbes  and chemicals have  been considered as potential tracers  to  identify  fecal
sources  in the environment.  However, to date, no single approach has been shown to accurately
identify  the origins  of fecal pollution in  all  aquatic  environments.   In a  European multi-
laboratory  study,  different  microbial and chemical indicators were analyzed in  order to
distinguish human fecal sources from nonhuman fecal  sources using wastewaters and slurries
from  diverse geographical  areas across Europe.   Twenty-six  parameters,  which were  later
combined to form derived  variables for  statistical analyses, were  obtained by  performing
methods that were achievable in all the participant laboratories and include  the following:
enumeration of  fecal coliform bacteria,  enterococci, clostridia, somatic coliphages, F+ RNA
phages,    bacteriophages   infecting   Bacteroides   fragilis   RYC2056   and   Bacteroides
thetaiotaomicron GA17, and total and sorbitol-fermenting bifidobacteria; genotyping of F+ RNA
phages;  biochemical  phenotyping of fecal coliform bacteria and enterococci using miniaturized
tests;  specific detection of Bifidobacterium adolescentis  and Bifidobacterium  dentium;  and
measurement of four fecal sterols.  A  number of potentially  useful  source indicators  were
detected (bacteriophages infecting B.  thetaiotaomicron, certain genotypes of F+ bacteriophages,
sorbitol-fermenting bifidobacteria,  24-ethylcoprostanol,  and epicoprostanol),  although no one
source identifier alone provided 100% correct classification of the fecal source. Subsequently, 38
variables (both  single  and derived) were defined from  the measured microbial  and chemical
parameters in order to find the best subset of variables to develop predictive models using the
lowest possible  number of measured parameters.   To this  end, several statistical or machine
learning methods were  evaluated and provided two successful predictive models based on just
two variables that provided 100% correct classification—(1) the ratio of the densities of somatic
coliphages,  and phages infecting  Bacteroides thetaiotaomicron to the  density  of  somatic
coliphages and (2) the ratio of the  densities of fecal  coliform bacteria and phages infecting B.
thetaiotaomicron to  the density of fecal coliform bacteria.  Other models with high  rates of
correct  classification were developed but they required higher numbers of variables (Blanch et
al., 2006).
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2.6    Pathogens and Pathogen Indicators

Many beach regulators and scientists believe that there are significant opportunities to utilize
specific pathogens or pathogen indices to better understand or characterize potential health risks
from recreational exposures.  Some reasons for not doing so, however, remain—especially that
pathogen  numbers are  generally significantly  lower and more variable than fecal indicator
organisms. Nonetheless, pathogens could be utilized to accurately determine risks as there have
been a number of studies that define actual human dose-response from oral exposures such as
may be encountered during swimming.  Enteric pathogens are found in  raw and even treated
sewage so there is  merit in using them in water  quality  monitoring to  assess the risks from
exposure.  Also, it is possible that an entire "class" of pathogen risks can be determined by the
presence of an "index pathogen" representing that group. The current capabilities of molecular
methods to detect, identify, and enumerate pathogens has increased regulators' and stakeholders'
interest in seeing these applied  to ambient water quality monitoring to  better protect public
health.

There  are a number of criteria  related capabilities  that may be provided by  use  of  specific
pathogen  or index pathogen monitoring, such as the following:   (1) determination of specific
pathogen residuals from sewage  discharges, the data from which could then be used to  conduct
quantitative microbial risk assessment (QMRA) studies to assess relative levels of public health
concern at a beach; (2) establishment of "model" pathogens and index pathogens  that could be
used to assess risks from new or reemerging pathogens (an example would be the use of a virus
model  to  assess the  recreational risks from avian  influenza [H5N1]  because this virus can be
released from infected human and animal  feces  [especially waterfowl] and  can  directly or
indirectly  contaminate recreational waters); and (3) determination of levels of pathogens  that can
subsequently be used in QMRA  studies to inform decision making relative to whether  or not a
beach should be closed or reopened after a closure.

There are  currently two approaches to pathogen detection, identification, and enumeration, (1)
the traditional culture-based techniques that are especially useful in determining viability of the
sampled materials; and  (2) the molecular-based methods (PCR, antibody-based, and metabolic-
based) that generally cannot distinguish between viable and non-viable  pathogens, but which
may be quite useful in further differentiating or speciating  pathogens in water samples.  The
culture-based methods  are useful for recreational waters in that they can determine if there  is a
viable disease risk from exposure while the molecular methods may not be capable of discerning
viability.

Moreover, the culturable isolate can be further characterized for the presence of human virulence
genes and compared  to clinical isolates in waterborne disease outbreaks. In contrast, molecular-
based methods  may  not be capable of discerning  viability although the  presence of virulence
genes can  also be assayed by molecular methods. Because molecular methods do not recover the
entire microorganism, further characterization of that microorganism is limited.

Specific tracking of host sources using molecular techniques for pathogens can be very useful in
setting TMDLs, as it can help identify the source of the pathogen and its magnitude.  Recent
improvements  in molecular  science  applications  have  brought  about  a  capability  to
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simultaneously sample and evaluate large numbers of pathogens (e.g., microarray technology).
Microarray technology still requires high concentrations of pathogens for detection.  However,
ambient waters generally contain pathogen levels below the limits of detection and are unevenly
distributed in the water matrix.  Thus, research is needed to determine how to best apply these
advanced  technologies for characterizing enteric and non-enteric  disease contaminants, their
levels, and potential risks associated with their presence in recreational waters.

Workgroup members expressed some concerns about using either specific pathogens or pathogen
class indices as a first tier monitoring requirement for infectious disease risks in a recreational
water setting.   First, pathogens are typically present in low concentrations in treated sewage,
receiving waters, and also in recreational waters; therefore, high volumes of water need to be
sampled, which is time consuming,  costly,  and  contributes to  analytical variability.  Second,
pathogen presence is typically sporadic in a community as many  waterborne diseases may not be
endemic, but are rather transient/episodic  so they  do not represent a constant contaminant source
of fecal  pathogens  to monitor.   Third, there  is  a variable  component in terms  of fecal
contributions from humans  and  various  animal  sources  in ambient waters that may  have an
impact on determining recreational exposure risks.   Typically,  a number of  the  bacterial
pathogens (e.g., toxigenic E. coli, Campylobacter) are found in both humans and animals, but
there  may be differences in strain virulence or infectivity potential from  different  sources.
Likewise, there are  a number  of protozoan  pathogens  that cross-infect animal species  and
humans (Giardia spp. and Cryptosporidium parvum). On the other hand, human enteric viruses
have a much more limited  host range and  except for a potential  few (e.g.,  hepatitis E virus
[HEV]), animal sources of enteric viruses are not a major public health concern in recreational
waters.  Lastly, it is important to note that at any given time only a small portion of the human
population may be infected and excreting any specific pathogen  or index pathogen. Thus, large
wastewater treatment systems may always contribute a small level of pathogens of concern while
septic systems or small treatment systems may not have enough contribution  from the infected
population to ensure that those effluents would contain specific pathogens of concern to use as a
routine measure of contamination—even if the disease organisms are endemic  in the population.
Also,  many types  of pathogens  are associated with  a seasonality or  periodicity  to their
occurrence in a given population.

It is reasonable to use specific pathogens or their index  organisms  (or model organisms)  in a
toolbox or tiered approach to monitoring if considered as other than as a first tier measure of
fecal contamination.  In a toolbox approach, the determination of the presence and concentration
of specific pathogens or their index organisms could be useful to characterize risks once it has
been determined that there is a trigger level of fecal contamination at a given recreational water
site. Dose-response data for a number of the primary pathogens  from oral exposures is available
and these data would help more narrowly define exposure risks for a detected pathogen.  Because
of the costs, time for analysis results, and expertise needed to test  specific pathogens  or index
organisms, these measurements would be the last set of measurements applied to monitoring of
recreational  sites for determining potential sources.  The specific pathogen monitoring  tools for
other  AWQC  applications  (e.g.,  TMDLs)  could allow States  to determine  sources  and
concentrations of the pathogens for particular upstream contamination events. Also, pathogens
could be incorporated into  future  NPDES permit limits  and be used  in  the future to assess
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wastewater treatment plant discharges for  specific  pathogens of concern downstream and to
provide a better understanding of the efficacy of treatment and disinfection processes.

2.7    Chemical Biomarkers of Fecal Contamination

Various  shortcomings  have been  identified  in  relying solely  on indicator  bacteria  or
pathogen/index  microorganisms  for  CWA  criteria  uses.   Methods for  MST  in aquatic
environments have been developed and discussed above that distinguish animal from human
sources in the United States and in Europe (Blanch et al., 2006).  However, for some specific
tiered approaches in sanitary investigations,  certain chemical biomarkers of sources may provide
timely or higher resolution information in fecal source tracking. Some of the most promising are
discussed below.

2.7.1   Fecal Sterols

The most commonly known fecal sterol, coprostanol  (5|3-cholestan-3|3-ol), is largely produced in
the digestive tract of humans and dogs by microbial hydrogenation  of cholesterol (Leeming et
al., 1996).  The term "sterols" is generally used for  all sterols and stanols (i.e., "fecal sterols")
and is also  a more specific term denoting a steroidal alcohol with at least some degree of
unsaturation.

Two pathways have been proposed for the biotransformation of cholesterol to coprostanol, one in
the gut and  the  other in natural sediments.  The  a-configured form (cholestanol) is the most
thermodynamically  stable  of  the  reduction products  and  is  found  ubiquitously  in  the
environment; whereas coprostanol is largely of fecal origin, but some reisomerization can yield
low levels in natural sediments.  Both forms are  easily resolved by gas chromatography-mass
spectrometry (GC/MS) analysis.

An important advance in using these fecal  sterols has been the realization that it is critical to
measure both the ratios and absolute concentration of at least four of these related compounds to
attribute fecal source contributions between humans, herbivores, and birds (Ashbolt and Roser,
2003).  Coprostanol alone has never really been embraced as  an indicator for sewage pollution
because its presence is not considered as indicative of a health risk due to multiple sources and
low level environmental production in sediments.

The fecal sterol biomarker technique offers many  diagnostic and quantitative advantages when
used in conjunction with traditional techniques for  detecting  sewage pollution.  When careful
data interpretation is  undertaken, fecal sterol  analysis, although  expensive  and complex,  has
resolved problems of source attribution in urban and  rural environments not possible with use of
traditional fecal indicator bacteria and coliphage assays (Roser and Ashbolt, 2007).

2.7.2   Caffeine

Caffeine has been extensively  examined as a tool  for assessing  human  influence on aquatic
systems. Although caffeine is metabolized when consumed, a  small amount (<10%) of ingested
caffeine remains intact when excreted (Peeler et al., 2006). Most work in the past decade has
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focused on heavily polluted systems and efficiency  of caffeine removal in sewage treatment
plants, although with improvements in techniques and the lowered detection limits, the scope of
application has broadened to include stream, wetland, estuarine, and groundwater systems.

A major disadvantage is that caffeine is often present in the urban environment from numerous
plant  species debris as well as from human "dumping" of coffee wastes.  Further, the  current
methods used (specific extraction and GC/MS analysis) are relatively complex and expensive.
Nonetheless,  based on the  recent work of Peeler et  al. (2006)  in southwest Georgia, caffeine
appears immediately  below wastewater  discharge sites and within towns, but  not in  rural
watersheds.  Overall, aquatic concentrations of caffeine are typically less than for  fecal  sterols,
but caffeine tends to stay in solution, whereas the sterols associate with fine particulates.

2.7.3   Optical Brighteners and Other Sewage Markers

Recent sewage contamination may be readily identified in waters by the presence of ammonium,
turbidity/particle counts, phosphate, odor, and a range  of organics present.  Depending on the
sensitivity and AWQC applications, some of these analytes may provide value in fecal source
identification.

One relatively inexpensive and sensitive  fecal  source  identification method is fluorometry
(Hartel  et al., 2007).   Fluorometry identifies human fecal contamination by detecting  optical
brighteners  (also  called  fluorescent whitening  agents) in  water.   Optical brighteners are
compounds added primarily to laundry detergents, and because these brighteners emit light in the
blue range (415 to 445 nm), they compensate for undesirable yellowing in clothes (Kaschig,
2003). In the United States, 97% of laundry detergents  contain optical brighteners (Hagedorn et
al.,  2005).   Because household  plumbing  systems mix effluent from washing machines and
toilets together,  optical brighteners are associated with human sewage  in  septic  systems and
wastewater treatment plants. However, in order to use optical brighteners to detect human fecal
contamination properly, they must be combined with use (counts) of fecal  indicator bacteria. For
example, effluent from a wastewater treatment plant  contains optical  brighteners, regardless of
how effective the treatment processes have been at removing or inactivating pathogens.  Thus,
data on the presence of optical brighteners without accompanying data on viable fecal indicators
does not provide information on the potential health risk from pathogens.

However,  results of studies that have combined fluorometry with counts of fecal bacteria have
been contradictory. Although various reports have documented a strong fluorescent signal and
high numbers of fecal  enterococci, cases of no correlation between fluorometry and counts of
fecal bacteria have also been reported (Hartel et al.,  2007).   One key confounder  has been the
presence of organic matter that fluoresces and interferes with fluorometry. Yet, this interference
can be  reduced  by adding a 436-nm  emission  filter  to the fluorometer,  which  may  reduce
background fluorescence by over 50%.  As long as the fluorometer used is equipped with a 436-
nm filter, it appears that targeted fecal  indicator sampling combined with fluorometry can be a
relatively inexpensive method for identifying human fecal contamination in water.
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In summary, chemical biomarkers appear to have niche applicability for those with the resources
and expertise to use them and where such biomarkers are advantageous, such as where other less
expensive MST options have shown to be unsatisfactory or provide ambiguous results.

2.8    Research Needs

2.8.1   Near-term (1 to 3 Years)

    1.  Validate the range and species or sub-species diversity qPCR assays identify, and how
       they may relate to health outcomes for recreational  exposures (also  using archived
       epidemiological study material) (high priority).
          a.   Example priority list of organisms:  enterococci, Bacteroides, C. perfringens, E.
              co//', F+ RNA coliphages, and somatic coliphages
    2.  Investigate the potential for speciation of enterococci to identify fecal-specific (preferably
       human)  from  environmental   strains,  then  apply  results  to  future  MST  and
       epidemiological studies (high/medium priority).
    3.  Ensure that archived samples  (collected  from  epidemiological/specific  studies) are
       suitably sorted and stored (to maintain their integrity) for future viability as well  as
       molecular-based   method   comparison   or   validation   studies    for   candidate
       indicators/methods (high priority).
    4.  Validate  C. perfringens (SRC)  assay's robustness over a range of water  and sediment
       sample characteristics and correlate  health effects relationships to this  indicator (high
       priority).
    5.  Determine if there are Bacteroides analytical targets  that are human-specific and validate
       their use over a range  of geographic  areas, diverse populations, climates,  and water
       quality conditions to correlate levels to health targets (high priority).
    6.  Conduct  health and epidemiological studies  with as wide a range of microorganisms
       (indicators/MST organisms)  as  possible to  identify risk correlations  for a range  of
       pathogens/indicators  (including bacteriophages) from various nonhuman  sources; at a
       minimum  would   include  E.  coli,   enterococci,  enterococci-qPCR,  coliphages,
       Bacteroides-PCR,  C.  perfringens;  where  possible,   Bacteroides  phage  GB-124,
       enterohemorrhagic E.  coli  (EHEC);  and check for absence of human Norovirus-qPCR,
       adenovirus-qPCR, Pan-enterovirus-qPCR, polyoma viruses (high priority).
    7.  Conduct  health  and  epidemiological  studies  with microorganisms from nonhuman
       sources such as Leptospira spp. in fresh and S. aureus  and  pathogenic Vibrio  spp. in
       marine recreational waters and determine appropriate  indicators for these  pathogens
       (medium priority).
    8.  Conduct epidemiological studies incorporating the measurement of pathogens of interest
       (along with indicators)  as monitoring  tools in sewage  in order  to determine the
       correlations of the  occurrence of these pathogens to indicators, and to better understand
       their association with diseases at downstream recreational locations. For instance, while
       it  is strongly  suggested that enteric viruses are major contributors  to illness  from
       swimming, there have not been  prospective epidemiological studies to actually support
       this association.   Use  serology (also  consider  collecting saliva and possibly  fecal
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       samples) to help identify the etiological agents from  sewage that are impacting on
       recreational water sites (high priority).
          a.  Conduct similar studies in recreational waters (above refers to studies in sewage)
              (medium priority).
    9.  Systematically identify  and evaluate more  reproducible, accurate, and cost effective
       methods to sample and identify priority pathogens or their index organisms (including the
       total adenoviruses,  [e.g., Groups A-F and adenovirus 40/41],  but also JC virus, and
       Norovirus) in ambient waters (medium priority).
    10. Determine if there are any appropriate sewage associated bacterial pathogens that can
       adequately serve  as an index of any of the currently  known sewage-borne bacterial
       organisms to use on a more routine basis in recreational water criteria.  For example,
       determine if monitoring recreational waters for Salmonella spp. bacteria and phages of
       Salmonella can  fulfill the criteria  of a pathogen index  for  sewage-borne bacterial
       pathogen can be developed (medium/low  priority).
    11. Conduct microbial   fate and  transport  studies  to determine relationships  between
       traditional and new fecal indicators, index pathogens, and priority pathogens in treated
       effluents  and in  downstream  recreational  waters  to  compare  and  validate  their
       applicability for specific criteria uses (high/medium priority).

2.8.2   Longer-term Research Goals

The research below may take longer than 2 to 3 years of research to complete.  These are not
presented in order of priority.

    1.  Review archived  samples to look for trends in evolution of viruses (new or cyclic re-
       emergence of viruses) and the efficacy of current indicator targets used by molecular
       methods for health based correlations.
          a.  Develop  predictive models  to  understand the  conditions  that  promote  the
              emergence or re-emergence of new pathogens.
    2.  Continue to conduct additional  epidemiological studies  on non-point  sources of fecal
       contamination and assess illness relationships to pathogen/indicators.
    3.  Continue to conduct  sewage surveillance for pathogens as a means  of public health
       surveillance and informing pathogen monitoring programs for CWA purposes.
    4.  Develop robust method for speciation of enterococci with a view to identify fecal-specific
       (preferably  human) from  environmental  strains; then  apply to  future  MST  and
       epidemiological studies (assuming initial studies suggest that this  should be explored
       further).
    5.  Conduct studies on beaches to characterize the usefulness of total adenoviruses (Groups
       A-F), adenovirus 40/41, JC virus,  and  Norovirus to meet recreational water quality
       criteria purposes.
    6.  Conduct health/epidemiological studies to identify  a range of pathogens/indicators from
       various nonhuman sources of fecal contamination.
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Davies, CM; Long, JAH; Donald, M; Ashbolt, NJ. 1995.  Survival of fecal microorganisms in
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Degnon, AJ. 2007. Examination of indigenous microbiota  and survival of E. coli O157:H7 and
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Ebdon,  J;  Muniesa, M;  Taylor, H.  2007.  The  application  of a recently isolated  strain  of
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Fujioka, R; Byappanahalli, MN. 2001. Final Report Tropical Indicator Workshop. Prepared for
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Furuse, K; Ando, A; Watanabe, I. 1975. Isolation and grouping of RNA phages. VII. A survey in
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Gauthier,  F; Archibald, F. 2001. The ecology of "fecal indicator" bacteria commonly found in
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Gawler, AH; Beecher, JE; Brandao, J; Carroll, NM; Falcao, L; Gourmelon, M; Masterson, B;
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Grabow, WOK;  Vrey, A; Uys, M;  de Villiers,  JC. 1998.  Evaluation  of the Application  of
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Hagedorn, C;  Saluta,  M; Hassall,  A; Dickerson, J.  2005. Fluorometric detection  of optical
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Kuntz, RL; Rivera-Torres, Y;  Otero, E; Schroder, EC. 2007. Improving fluorometry as a source
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Hsu, F; Heih, C; Van Duin, J; Beekwilder, M; Sobsey, M. 1995. Genotyping male-specific RNA
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Kay, D; Bartram, J; Priiss, A;  Ashbolt, N; Wyer, MD; Fleisher, D; Fewtrell, L; Rogers, A; Rees,
G.  2004.  Derivation of numerical values for  the  World Health  Organization guidelines for
recreational waters. Water Research 38(3): 1296-1304.

Kreader, CA. 1995. Design and evaluation of Bacteroides DNA probes for the specific detection
of human fecal pollution. Applied and Environmental Microbiology 61(4): 1171-1179.

Krometis, L-AH; Characklis,  GW; Simmons, ODI; Dilts, MJ; Likirdopulos, CA; Sobsey, MD.
2007.  Intra-storm variability in  microbial  partitioning and  microbial loading rates.  Water
Research 41(2): 506-516.

Leeming,  R; Ball, A;  Ashbolt, N; Nichols, P. 1996.  Using  faecal  sterols  from humans and
animals to distinguish faecal pollution in receiving waters. Water Research 30(12): 2893-2900.

Leeming,  R; Nichols, PD; Ashbolt, NJ. 1998. Distinguishing Sources  of Faecal Pollution in
Australian Inland and Coastal Waters using Sterol Biomarkers and Microbial Faecal Indicators.
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Lehner, A;  Loy, A; Behr, T;  Gaenge, H;  Ludwig,  W; Wagner,  M; Schleifer,  KH. 2005.
Oligonucleotide  microarray for  identification  of enterococcus species. FEMS Microbiology
Letters 246(1): 133-142.

Liu, L; Phanikumar, MS; Molloy, SL; Whitman, RL;  Shively, DA; Nevers, MB; Schwab, DJ;
Rose, JB.  2006.  Modeling the transport and inactivation of E.  coli and enterococci  in the near-
shore region of Lake Michigan. Environmental Science and Technology 40(16): 5022-5028.

Love, DC; Sobsey, MD. 2007. Simple and rapid F+ coliphage culture, latex agglutination, and
typing (CLAT) assay to detect and source track fecal contamination. Applied and Environmental
Microbiology: In press.

Luther, K; Fujioka, R.  2004.  Usefulness of monitoring tropical streams  for male-specific RNA
coliphages. Journal of Water and Health 2(3):  171-181.

Osawa, S; Furuse, K; Watanabe, I. 1981. Distribution of ribonucleic acid coliphages in animals.
Applied and Environmental Microbiology 41:164-168.
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Peeler,  KA;  Opsahl,  SP;  Chanton, JP.  2006. Tracking anthropogenic inputs using  caffeine,
indicator bacteria, and nutrients in rural freshwater and urban marine  systems. Environmental
Science and Technology 40(24): 7616-7622.

Roll, BM; Fujioka, RS. 1997. Sources of faecal indicator bacteria in brackish, tropical stream
and their impact on recreational water quality. Water Science and Technology 35(11): 179-186.

Roser, DJ;  Ashbolt, NJ.  2007.  Source  Water Quality Assessment and the Management of
Pathogens in Surface Catchments and Aquifers. Research Report 29. CRC for Water Quality and
Treatment, Bolivar.

Seurinck, S;  Verdievel, M; Verstraete, W;  Siciliano, SD. 2006. Identification of human fecal
pollution sources in a coastal area: A case study at Oostende (Belgium). Journal of Water and
Health 4(2): 167-175.

US EPA (U.S. Environmental Protection Agency). 1986. Ambient Water Quality  Criteria for
Bacteria-1986. EPA440/5-84-002. Washington, DC: US EPA.

US EPA. 2004. Water quality standards for coastal and Great Lakes recreation water. Federal
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Wade, TJ; Pai, N; Eisenberg, IN; Colford, JM. 2003. Do U.S. Environmental Protection Agency
water quality guidelines for recreational waters prevent gastrointestinal illness? A systematic
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Walters, SP;  Gannon,  VPJ; Field, KG. 2007. Detection of Bacteroidales fecal indicators and the
zoonotic pathogens  E.  coli  O157:H7,  Salmonella,  and  Campylobacter in  river  water.
Environmental Science and Technology 41(6):  1856-1862.

Whitman, RL; Nevers, MB; Byappanahalli,  MN.  2006.  Examination  of the watershed-wide
distribution of Escherichia coli along Southern Lake Michigan: An integrated approach. Applied
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Wiedenmann, A; Kruger,  P; Dietz, K; Lopez-Pila, JM; Szewzyk, R; Botzenhart,  K.  2006. A
randomized  controlled trial assessing infectious disease risks from bathing in fresh recreational
waters in relation  to the concentration of Escherichia coli, intestinal enterococci,  Clostridium
perfringens, and somatic coliphages. Environmental Health Perspectives 114(2): 228-236.
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                                CHAPTER 3
                        METHODS DEVELOPMENT
         Stephen Weisberg, Chair, Southern California Coastal Water Research Project
         Alfred Dufour, USEPA
         Charles Hagedorn, Virginia Tech
         Sharon Kluender, Wisconsin State Laboratory of Hygiene
         Erin Lipp, University of Georgia
         Robin Oshiro, USEPA
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3.1    Introduction

The Methods Development workgroup focused on addressing the following four key questions:

    1.  What are the attributes and criteria for deciding whether  a new method or indicator is
       ready for adoption by EPA?
    2.  What kinds of studies are necessary to quantify those attributes?
    3.  Are there any new indicators/methods for which those studies have been conducted and
       that are ready for adoption?
    4.  What studies (or modifications to planned studies) are most critical for EPA to implement
       in  the  next  3  years to  support adoption  of new  methods/indicators  in  a criteria
       development framework?

A critical starting point for the workgroup members was recognition that  the  evaluation  of
methods and/or indicators needs to be considered in context of  the Clean Water Act (CWA)
applications in which they would  be used. The following five primary uses were identified by
workgroup members:

    •   Routine beach monitoring to support public health warning notification systems;
    •   Routine beach monitoring data to support total maximum daily load (TMDL) decisions;
    •   Rapid methods to track the progress of a  sewage spill as it  moves  downstream  or
       downcoast to improve the beach closure determinations;
    •   Compliance assessments conducted  at the terminus  of  National  Pollutant  Discharge
       Elimination System (NPDES) discharge pipes; and
    •   Trends assessments to determine whether water quality conditions at a site are changing
       over time.

The workgroup focused on the first two applications beacause  members felt that they are  most
relevant to EPA's  desire to redefine their current recreational water quality criteria.  However,
several workgroup members also  recognized the relevance of the other applications  so a  short
section is included (see Section 3.7) that illustrates the similarities and differences in the method
evaluation process for these other CWA uses.

For water  quality  notification systems, two principal issues were identified that need to be
addressed.  The first is that current laboratory measurement methods require  up to 24 hours to
enumerate indicator bacteria.  Contaminated beaches remain open during this processing period,
but indicator bacteria may already have  returned to acceptable  levels by the  time  laboratory
results are  available and warning  signs are posted.  Continued advances and improvements in
molecular- and immunological-based  techniques provide new  opportunities for  measuring
bacteria more rapidly.  Although current (traditional/standard) methods rely on bacterial growth
and metabolic activity, these new  methods allow direct measurement of cellular attributes,  such
as genetic  material or surface immunological  properties.  By eliminating the necessity for a
lengthy incubation step, some of these methods have the potential to provide results in less than
4 hours, enabling managers to take action to protect public health (i.e., post  warnings or close
beaches) on the same day that water samples are collected.  This assumes that samples can be


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processed at the beach or that the time required for transportation to a laboratory is brief. For
same  day posting to be achieved,  the  results of the  tests  also have to be delivered to and
evaluated by beach managers in a timely manner.

The second issue workgroup members identified is that present standards used to evaluate
recreational water quality data are based on a "one-size-fits-all model," relying on use of a single
indicator (e.g., enterococci  at marine beaches) and a single standard for all recreational waters.
There is growing recognition that  enterococci measured on the beach may  derive from  many
sources,  including humans, domesticated animals, indigenous wildlife (including shore and
migratory birds), and regrowth in sand, sediments, or on biofilms.  The health risk to humans
varies depending on which of these sources  is responsible for the measured enterococci.  As
such,  existing warning systems  do  not  provide an equal level of health risk protection  at all
beaches. Moreover,  the costly cleanup  processes associated with the TMDL programs are not
necessarily focused on the beaches that represent the greatest public health risk.   There are
additional concerns that cleanup activities, and associated costs, are being targeted at beaches
where  enterococci  concentrations  that  exceed  standards  result from natural sources and
processes.

EPA could consider two means of adjusting their  criteria framework to address one-size-fits-all
concerns. The first adjustment is to develop additional indicators to replace,  or to augment in a
tiered fashion, the existing  enterococci indicator as it is now used at marine  beaches (US EPA,
1986).  These new indicators would be more specific to human  sources and better related to
human health risk than the existing indicator.

The second potential adjustment is to adopt  a framework similar to that of the World Health
Organization  (WHO, 2003), in which watershed characterization studies are  used to adopt site-
specific standards.  These  site-specific standards  would be based on  perception of health risk
resulting from the types of fecal sources in the watershed and the proximity  of those sources to
the beach.  The Methods workgroup members felt strongly that source identification methods
needed to be a key tool in characterizing risk  and that further evaluation of source identification
methods needed to be conducted if they are to  be used in this context.

This chapter  is  organized  around  describing the approach  that would be  used for assessing
methods/indicators in the following three contexts:  (1) replacement of existing methods with
more rapid methods, (2) replacement of existing indicators with those that are more specific to
human sources of fecal contamination, and (3) determination  of source identification methods
that can be used to characterize risk in the development of site-specific standards. Within each
section, the adequacy of evaluations of methods/indicators is discussed and the most immediate
research activities that would provide the greatest benefit to EPA for modifying monitoring
and/or indicators within the next 5 years are highlighted.

3.2    Classes of Indicators

The evaluation of methods  is a critical element in bringing new technology to the measurement
of  water quality.   Current evaluation protocols were  developed  for cultural methods  for
enumerating bacterial indicators of fecal  contamination. The evaluation usually included method
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attributes regarding the performance of the method, such as specificity, accuracy, and precision.
Further evaluation that addressed how the method performed in and between laboratories
included multi-laboratory testing that determined how robust a method might be (i.e., how poorly
can the method be performed and still  produce useful  results?).  The question that arises is
whether the current protocols for evaluating membrane filter  culture-based methods are suitable
for evaluating new methods that are being proposed for  measuring water quality.  Some  of the
new or alternative methodologies that are available for testing water quality include molecular-
based methods, such as quantitative polymerase  chain reaction  (qPCR), nucleic acid sequence
based amplification (NASBA), and transcription-mediated amplification (TMA). These methods
amplify nucleic acid sequences  to high levels such that they can be  easily detected.   Other
methods use  antibodies to which fluorescent compounds are attached.  The fluorescent-tagged
antibodies then attach to specific microbes and are "counted" in a flowcytometer.  The preceding
methods "count" dead and live bacteria and thus differ  significantly from currently used
quantitative cultural methods.

Some recent methods do measure viable microbes in an indirect manner. For example, enzyme-
based  methods measure  substrate utilization  employing  compounds that fluoresce  when
metabolized by specific bacteria.  Comparison of the fluorescence to a standard curve allows a
"count" to be established.   Another method measures adenosine triphosphate (ATP) using a
bioluminescence measuring instrument to determine the amount of ATP that is produced only
from viable bacteria.

In the  current context,  there are indicators available or  in late  stages of development that are
ready for evaluation to determine if they are appropriate for use in routine beach monitoring.
Some can be measured with the technology described above while others can be measured with
currently available methodologies.

Leading candidates are indicators and detection methods that can be used to replace current
culture-based indicators of water quality (i.e., enterococci andE1. coli). For instance, nucleic acid
sequences from enterococci have been used to measure the density of enterococci in bathing
beach  water.   Some aspects of the  performance of this  method have been completed.  As
described above, enterococci have also been quantified using a fiber optic/fluorescent antibody
detection method, an enzymatic/substrate method, and a method that measures ATP.  None of
the latter methods have been evaluated with respect to either their performance characteristics or
for robustness.  Similarly, molecular-based methods that measure viruses  (e.g., adenoviruses)
that might replace currently used indicators of recreational water quality have not  had their
performance evaluated.  If these indicators are shown to be effective in  their performance, they
will be candidates  for  use in epidemiological studies to determine how well their densities in
recreational waters relate to swimmer health.

Another class of microbes  and other analytes  are  related to  identifying  the source of fecal
contamination that might affect beach microbial water quality.  Other markers include  genes
such as the Esp gene from enterococci, which might be specifically associated with human feces;
male-specific (F+)  coliphage that can indicate whether water  has been contaminated by humans
or animals; and chemical markers such as optical brighteners, caffeine, coprostanol, and urobilin
that may be associated  with human use or are the end-products of human metabolism (see also
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Chapter 2).  Optical  brighteners are measured quite easily  with a spectrofluorometer, while
caffeine, coprostanol,  and urobilin  require  more  complex  instrumentation,  such as  a high
performance liquid chromatography  (HPLC) instrument.  Measuring genomic markers is  less
complicated and does not require a thermocycler to perform  a PCR test.  The varied  nature of
these  source  identification markers  may  require modification of the performance evaluation
criteria  to  accommodate the different characteristics of these source specific  analytes.  For
instance, the range of applicability and practicality may be more important than the accuracy and
precision characteristics of these chemical or genomic source identification approaches.

The last class of indicators that may be ready for evaluation as indicators of fecal contamination
are those that may have been rejected previously, for whatever reason, but should be considered
again because of the availability of new information about their occurrence in water or because
of new methods for their detection.  Other potential indicators may be candidates because they
are species within a  group indicator,  such as the enterococci  and clostridia,  and individual
species may better indicate the quality of a waterbody.  It is likely that this class of indicator will
fit well into the current paradigm for characterizing microorganisms that  might be used for
routine recreational water quality monitoring.

3.3    Evaluating New Methods for Existing Indicators

Workgroup members felt that  after  a method passes  defined performance criteria, it must be
evaluated  for its application as an equivalent (or superior) water quality tool  compared to the
current assays.  An example of when this approach might be used is the transition from culture-
based enterococci detection to detection by a rapid (molecular-based) assay.

The workgroup identified two major approaches to  conduct this evaluation, (1) determining the
relationship to health risks based on epidemiological studies or (2) establishing equivalency to an
existing water quality tool.

3.3.1   Health Risk Evaluation

Workgroup members felt that determining the relationship to health risk is the best approach to
evaluating  a new method.  An  epidemiological  study that can associate human risk with a new
method is the preferred approach.  The new detection method will ideally  show an  improved
relationship to illness and will therefore be more protective of public health than the  current
approach  that  relies  on  indicator  detection.   Likewise,  if the  new  method offers other
improvements over the existing method (e.g., more  rapid, less costly, etc.), then  its relationship
with human health should be at least as good as the current indicator.

The health risk evaluation should also be used when the target of the new method differs
significantly from  the current system. For example, a culture-based enterococci  assay does not
measure the same thing as a polymerase chain reaction (PCR)-based assay, which detects DNA
rather than culturable (viable) cells.  In these cases, a direct comparison of methods (as  described
below) may not be appropriate or possible.
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3.3.2   Establishing Equivalency between New and Standard Methods

The equivalency validation approach assumes that for methods with similar targets (e.g., viable
cells),  the performance of the new method can be compared to  that of the  existing method
without the need to determine health risk directly. Given the cost and time involved in large
scale  epidemiological  studies, the  equivalency  approach can be performed  for  many  new
methods.  The EPA should determine how dissimilar the method targets can be and still be
evaluated by this approach.  For  example, cellular activity-based assays (e.g., immunomagnetic
separation and ATP bioluminescence [IMS/ATP]) and membrane-filtration assays both measure
viable  cells, even though the end points are different.  The workgroup members suggested that
this activity-based assay is  similar enough to be evaluated through equivalency validation.  This
level of flexibility is important because of the limited number of epidemiological studies that can
be carried out in the near- or long-term.

The current EPA  (2003)  protocol, EPA Microbiological Alternate Test  Procedure  (ATP)
Protocol for Drinking Water, Ambient Water, and Wastewater Monitoring Methods., provides a
suitable vehicle for performing these evaluations.  The EPA recommends approval of a proposed
method if it is similar or better than the approved method (the "gold standard") for 80% of the
matrices tested.  Currently, only culture-based methods  can  be  included as an  alternate test
procedure; therefore, consideration should be given by the EPA on the comparability of other
methods (as mentioned above).

Along  these lines, California has  adopted equivalency validation between methods with different
targets (i.e., culture-based versus  PCR-based). This protocol, Beta Testing of Rapid Methods for
Measuring Beach Water Quality  (SCCWRP, 2007), provides guidelines for comparing between
methods.  Similar to EPA, this validation  compares method performance between  multiple
sample types and laboratories and also sets acceptable variability between results at 0.5 log
(based on within method variability previously  reported [Griffith et al., 2006; Noble et al.,
2003]). Additionally, the precision should be equal to or better than for the existing methods.

Many  workgroup members felt  that EPA's protocol is too  prescriptive because it disallows
applications for methods that are  not culture-based. In the future, for example,  should the IMS-
ATP test be found to have a health risk-based association, EPA should consider allowing its
comparison to culture-based methods since both assay for live organisms, albeit not exactly via
the same mechanism (membrane-filtration colonies or Most Probable Number [MPN] results
versus  ATP occurrence).   By the  same token,  workgroup members felt that the California
protocol was too relaxed in that genetic methods were compared to culture-based methods for the
purposes of acceptance of the former. Because these methods do not measure  the same targets
(DNA  versus  membrane-filtration  colonies),  this was perceived as  comparing  "apples to
oranges" as the criteria for making such comparisons are not yet well established.

3.4    Performance Criteria

Regardless of which of the two  evaluation approaches is chosen (health risk-based or method
equivalency-based), performance criteria for the method should be completed, and preferably
before  using the method in an epidemiological study to obtain heath risk-based association data.
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Workgroup  members consider the following to be the major parts  of performance criteria:
repeatability,  accuracy,  specificity,  sensitivity,  robustness,  range  of  applicability,  and
practicality.  These performance criteria are summarized below.

Repeatability asks the question: if a test is repeated, will the results be the same?  Note, this does
not take into account the degree of error  with regard to how well the test does at identifying its
target (accuracy).  For  example, if a person is throwing darts at a target,  repeatability is the
measure of how often the darts hit a specific place.  Repeatability  does not measure whether one
hits  the center of the  target or not—that is  accuracy (see more below).  Repeatability  is
sometimes referred to as precision and can be expressed both on an absolute scale (i.e., standard
deviation) and on a relative scale (i.e., relative standard deviation [RSD]).  The RSD (sometimes
referred to as coefficient  of variation) is calculated as the standard deviation  divided by the
mean, expressed as a percent.  For the purpose of summarizing data, both  standard deviations
and  RSDs should be calculated.   Generally, RSDs  are  most  appropriate for summarizing
precision when variability increases as concentration increases.  To provide  an indication of the
effect of multiple matrices on precision,  standard deviations should be calculated separately for
each matrix  as well as for the method  over all matrices.   In addition to within  and among
matrix/matrices for repeatability, it is  important to test intra- (within lab) and inter-laboratory
(among labs) repeatability to ensure consistency.

Accuracy  measures the degree to which the method identifies its target.   It is defined as the
degree of agreement between an observed value and  an accepted reference value.   Accuracy
includes random error (precision) and systematic error (recovery) that are caused by sampling
and analysis. Using the above dart example, this would be the number of times that the dart hits
the "bulls-eye."

Specificity includes the false positive and false negative rates. The false positive question asks if
the method  is significantly more likely  or less likely to detect non-target  organisms or other
sample constituents that would be reported as the target organism by the analyst when compared
to the reference method.  To assess whether the false positive rates are significant, replicates
known to contain non-target organisms that  could  be  falsely identified as the target organism
should be analyzed.  The determination that the samples  do not contain the  target organism
should be based on a third independent standard method. For example, if the target organism is
cultured E.  coli,  the test should be used against, at a minimum, other enter ob acted a, and,
depending on what the  test is, potentially Gram positive organisms as well.  If the test is for
genetic material,  then the primers and probes should be tested  against GenBank  to look for
potential false positives  from non-E1.  coli  species with the same sequences.  Specificity also asks
the false negative question regarding whether the new method is significantly more or less likely
to exhibit  non-detections for samples with the target organism or to exhibit results that are biased
low when compared to the reference method.   To assess whether the false negative rates are
significantly different between methods, replicates known to contain target organisms should be
analyzed.  As in false positive studies, the determination  that the samples do not contain the
target organism should be based  on  a  third independent standard method.   For  example, if the
target organism is genetic  material from E. coli, then a method for culturable E. coli can be used.
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If the culture method is able to detect E. coli, then the genetic method should, in general, also
detect E. coli.

Estimates of false positive and negative rates as percentages can be calculated as follows:

    1.  false positive rate = # false positives/(# of true negatives + false positives) x 100%; and
    2.  false negative rate = # false negatives/(# true positives + false negatives) x  100%.

The sensitivity of a test is the analytical detection limit of the test (the smallest amount detectable
using the method).   For chemical  methods, the  sensitivity may be  defined as the minimum
amount of a particular component that can be determined by a  single measurement with a stated
confidence level.  Generally, these refer to instrument analysis;  thus, it  is the lowest quantity of a
substance that can be distinguished from the absence of that substance (a blank).  For microbial
methods, sensitivity is the limit of detection of a particular method.  In general, methods are not
used at this level since confidence around that level is lower and more subject to user error.

The robustness of a test is the degree to which the method  can perform  in the presence of
incorrect inputs or stressed conditions.  More simply,  how poorly can a method perform and still
produce useful results?   For example,  does the method perform as intended in the hands of a
semi-novice user (e.g., a qPCR method performed by  a person familiar with molecular-based
methods including PCR but  not qPCR)? If the test is for cultured microorganisms, can it detect
stressed organisms in ambient  waters (e.g., the EPA E. coli methods have a 2-hour resuscitation
step at a lower temperature for stressed  organisms)? Robustness is not  a measurable attribute per
se but must be considered and applied for overall method performance.

The range  of applicability should also be considered  as  it  answers  the question:   is the test
reliable on a nationwide basis (e.g., does it work equally well in temperate and tropical climes, in
the  Great Lakes  and other  inland waters, etc.), in the presence of inhibitors (e.g., turbidity,
alkalinity, organics [humic acids]), and in a variety of matrices  (e.g., sewage, septic tanks, urban
runoff, agricultural waste, known animal sources)?  In general, the range of applicability does
not apply to matrices other than the one for which the test was designed; that is, a recreational
water quality method should not be expected to perform equally well for sewage sludge. Like
robustness, this is not a measurable attribute but  must be considered and  applied for overall
method performance.

Workgroup members felt that practicality should also be considered when considering a method.
This issue is largely addressed in Chapter 7 (Implementation Realities workgroup).  However,
four main issues were considered important enough to be mentioned here—capital cost, training
cost, per sample cost, and additional sampling requirements.   Capital  costs include the upfront
costs such as equipment purchase and the actual space required for the test. For example, when
performing genetic testing, aside from the equipment needed (e.g., platform  [specific machine],
laminar flow hoods,  dedicated pipettors), space is needed, ideally in separate rooms, for reagent
preparation (material not containing any genetic materials).  Space is also needed for the two
types of sample preparation, those containing high target sequence DNA concentrations such as
DNA standards and calibrator samples, and those containing expected low target sequence DNA
concentrations (e.g., filter blanks and  water samples)—the  latter of  which should also be in
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separate laminar flow hoods. Training costs are those incurred prior to routine testing so that the
user can  perform the  test within the performance criteria of the test;  these  may include
participation in a workshop for hands-on experience or completing a training module. The other
two issues regard routine use of the test.  A high per sample cost may become an issue if a large
volume of tests need to be  completed on a routine basis.  Additional sampling is generally an
effort that results from  rapid testing.   For example, if an early morning sample yields,  after 4
hours,  a positive result resulting in beach closure, it may then lead to additional sampling to
determine if the beach still  needs to be closed in mid-afternoon.  It should be noted that many
laboratories (at least in California) do not object to capital or training costs, but take issue with a
high per sample cost or with additional sampling requirements.

3.5    Evaluation Process  for Alternative (New) Indicators

Currently, recreational water quality is assessed with a single indicator with a single threshold
(i.e., a "one-size-fits-aH" approach).  Under consideration is the implementation of alternative
indicator(s)  that are  better associated with human health risk  than the  enterococci.  These
alternative indicators could  theoretically replace the current standard but still be used in a one-
size-fits-all  approach or could be targeted for specific applications (e.g., one indicator may be
best associated with  risk in tropical  marine waters,  another  in temperate marine waters,  and
another in freshwaters).  Regardless of the final implementation, any new proposed indicator will
need to be vetted through performance based standards.

The system  of approving an alternative indicator will follow the same process as outlined for the
assessment of any indicator or method, although there will be key differences.

    •   Any  proposed  indicator  and/or  method  should  be  evaluated  for the  following
       performance characteristics:
       o  repeatability  (i.e., precision);
       o  accuracy;
       o  sensitivity;
       o  specificity (false  positive/false negative);
       o  robustness;
       o  range of applicability; and
       o  practicality.
    •   After performance  characteristics have  been  demonstrated  and  the indicator  and
       associated method has been determined to have adequate performance, it then should be
       evaluated for its  use and application in a water quality criteria, including:
       o  relationships to health  risks must be  established based on  epidemiological  studies
          covering an array of beach types and/or geographic areas; and
       o  because of lack of comparable standards, a new indicator cannot be evaluated based
          upon equivalency to an existing method.

This approach  would establish  the basis for alternative (new) indicators, and leads into the
possibility that such indicators could also serve in a role as source identifiers.
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3.6    Evaluating Source Identification Methods - Proficiency and Evaluation

When bacterial levels in recreational  waters exceed adopted State Water Quality Standard, the
potential risk to the public health requires local authorities to post advisories or close swimming
areas, risking significant losses in local revenue. The goal of microbial source tracking (MST),
as applied to U.S. waters, is to accurately identify the contributors and, if possible, the relative
proportions  of fecal pollution  from  all  potential  sources, or at least the major  contributors.
Proper use  of MST can assist watershed managers in implementation  of best  management
practices (BMPs) that can reduce fecal inputs, thereby limiting or reducing public health risk.

Two major classes  of microbe-based  and one  class  of chemical-based MST  methods are
currently being developed and utilized in surface waters across the world (Blanch et  al., 2006;
Stoeckel and Harwood, 2007).   Although there has been significant progress in the MST field
over the past decade, variability among performance measurements and validation approaches in
laboratory and field studies has led to a body of literature that is very difficult to interpret, both
for scientists and for end users (Stewart et al., 2003; Stoeckel et al., 2004).  This section lists and
defines/describes  performance  characteristics that should be uniformly  applied  across MST
studies, although  selection of which criteria from the following list to use will vary somewhat
based on the target.  All methods  and MST  projects  need to include some considerations for
representative sampling, sampling frequency, sample volumes required,  and the  number and
choice of source categories.  Although the use of a  toolbox approach has been important in MST
studies, there is a desire to develop an appropriate  tiered approach to avoid costs and time from
using multiple methods simultaneously.  Within the MST community, and largely as a result of
the method  comparison  studies, library-independent methods are currently the  priority, while
chemical-based methods appear to be desirable for rapid screening and presence-absence tests
(with perhaps quantification in the future).  Library-based methods still have a role in MST, but
only in those circumstances where detailed information is needed, such as many TMDL-based
studies.

3.6.1   Library-independent Methods (also Reported as Sample-level Classification)

Examples (not comprehensive) include both molecular approaches (Bacteroidales, E. coll toxin,
Enterococcus Esp gene, direct measurement of source-specific viruses (polyoma, adenoviruses,
enteroviruses, phages, etc.) and microbe-based approaches (Clostridium perfringens [alternative
indicator],   source-related   clostridia,   source-related  enterococci,   sorbitol   fermenting
bifidobacteria  [human],  Rhodococcus   copraphilus   [grazing  animals],   human-specific
bacteriophages, phage typing, etc.).

Method evaluation includes the following eight performance criteria:

    1.  Accuracy  is  defined as  the true positive  or  success rate—if a method identified the
       presence of the target in 98 out of 100 blind samples, the accuracy would be 98%;
    2.  Rates of false negatives and false positives of the  target are used to describe specificity;
    3.  The analytical detection limit of the test is used to describe  sensitivity;
    4.  The level of target-host specificity and the range of target-host distribution;
    5.  Efficiency of recovery of the target from different environments;
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    6.  The reproducibility of analytical results, both inter- and intra-laboratory;
    7.  The  suitability  of  marker  detection  (and/or  quantification)  to  meet  study-specific
       objectives; and
    8.  Detection of several of the above, especially #4 and #5, can be referred to as robustness.

3.6.2   Non-microbial Methods (also Called Chemical Methods)

Examples of non-microbial indicators include, but are not limited to,  optical  brighteners, host-
derived DNA  (e.g., eukaryotic mitochondrial DNA), fecal sterols/stanols, and source-specific
fecal compounds such as caffeine and pharmaceuticals for humans.

The performance criteria in numbers 1  through 8 above,  excluding #4 and #5, apply to non-
microbial methods.  For chemicals, the analytical detection limit of the test is usually applied to
describe both  sensitivity  (#3) and the  efficiency of recovery  of the target from different
environments (#5).

3.6.3   Library-based Methods (also Called Isolate Matching)

Examples of library-based  methods include but are not limited to both molecular approaches
(pulsed-field gel electrophoresis [PFGE], ribotyping, PCR with different primer sets, etc.)  and
phenotype-based approaches (antibiotic resistance analysis [ARA], biochemical, etc.).

The performance criteria in numbers 1 to 3 from library-independent methods (above)  are
applicable for library-based methods. In addition, the following four criteria apply:

    1.  Jackknife (also reported as holdout or cross-validation) analysis and the pulled-sample
       test (recently described as internal proficiency) should be done  on each and every library
       (Stoeckel and Harwood 2007);
    2.  Library should shave clones removed to reduce redundancy, based on the precision of the
       typing method;
    3.  External  proficiency or blind tests to determine both size and  representativeness of the
       library  should be done as the library is developed; and
    4.  The  benefit-over-random  statistic  should  be used when  accuracy is  determined,  and
       should  be performed on both the library and the external proficiency (or blind) set.

3.7    Modifications  to  the Evaluation Process When  Indicators are  used  for Other
       Applications

Indicators are used in many different contexts. Routine beach monitoring, the most time-critical
use of indicator  bacteria is described  extensively  in other chapters of these proceedings. This
section briefly addresses other (secondary) uses of indicators.  Another use of indicators is as an
early warning  system that would provide evidence for an imminent human  health risk, such  as a
sewage spill.  They can also provide evidence of returning to acceptable ambient water quality
conditions as designated by the criteria.  It is important that the methods be highly specific  and
robust.  Because of the potential for illness in exposed populations, it is extremely important  that
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this use of an indicator be associated with great specificity and robustness.  Specificity in this
case refers to the ability of a method to detect an indicator with certainty that the indicator is not
giving a false positive response (i.e., an organism or analyte that responds similarly to the target
organisms, but is not the target organism).   Similarly, target microbes that  do not provide a
positive response are indicated as false negatives and too many of these could result in a false
sense  of  security that  would  be highly  unacceptable  from  a public  health  perspective.
Robustness  in  this case means that the  method  can be abused  and still function properly.
Methods of this type are usually used under extreme conditions where the correct result must be
obtained in a very short time period.

Another use of indicators is for compliance monitoring purposes, such as monitoring sewage
treatment  effluent for EPA's NPDES Program.  Important characteristics for indicators used for
such compliance monitoring are precision and specificity.  The precision is necessary  because
sewage treatment plants would receive a fme(s)  if limits of the permit are exceeded.  The
specificity, both false negative and false positive responses, are important for the  same reason
mentioned above and may influence the way beaches are managed.

Trend assessments are used to  determine whether water quality conditions at a site are changing
with time.  The most important characteristic is precision that contributes to the ability to detect
small changes over time (i.e., whether the water quality is decreasing or improving over time). If
the water  quality decreases then bathing may no longer be allowed.  Conversely, if the water
quality improves sufficiently then bathing may be re-allowed.

3.8    Research Needs

Several lines of research should be pursued in order to implement improved methods for (1)
rapid detection of current water quality indicators, (2) implementing alternative indicators that
are more protective of public  that the  current indicators, or (3) determining source (human or
nonhuman) at beaches.  This set of research priorities is based upon the current state of available
methods and the projected feasibility of implementation in near-term (1 to 3 years) and mid-term
(2 to 5 years) or longer timeframes.  Although these are listed in priority order, the workgroup
members felt that they largely  expand on efforts that EPA or  its potential partners have already
initiated and all are achievable in the next 3  years.  Appendix G summarizes currently  planned
measurements for use  in the upcoming Doheny and  Malibu Beach  (California) epidemiology
study.

    1.  Systematic  evaluation  of  performance   criteria   for   library-independent   source
       identification methods (for use  in source characterization [i.e., human versus nonhuman
       fecal contamination] and in MST) (timeline: 1 to 2 years).

       Workgroup members felt that EPA should fast-track studies to evaluate the  performance
       criteria of source-specific microbial targets.

       A  series of controlled  trials representing  a  variety  of geographical areas should  be
       conducted to  evaluate promising methods.  Studies should include samples spiked with
       known  source  fecal matter from  multiple hosts  as well as  environmental  samples
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       collected from areas with known dominant sources of fecal  contamination.  Samples
       should be assayed by the test methods  in  several  laboratories using blinded controls.
       These protocols would be similar to those used in the Griffith et al. (2003) studies that
       EPA co-sponsored approximately 5 years ago, but which need to be updated as new
       methods have developed and existing methods refined.

       Although there are many potential  methods that could be included in such studies, the
       workgroup members identified the following as the most important:

          1.   enterococci Esp gene;
          2.   E. coli virulence genes;
          3.   human enteric viruses (molecular detection);
                 a.  DNA-based - adenoviruses and polyomavirus;
                 b.  RNA-based - enterovirus and norovirus;
          4.   Methanobrevibacter smithii (nifli gene);
          5.   Clostridium perfringens;
          6.   coliphage; and
          7.   Bacteroides human-specific markers.

       The last two methods are also being planned for use in EPA's upcoming (2007) health
       risk (epidemiological) study.  The workgroup members  felt that  the coliphage and
       Bacteroides methods are more advanced than the others and endorses their inclusion in
       source identification studies.

       In coordination with trials over various geographic areas, candidate methods should also
       be evaluated from the perspective of persistence  of genetic or chemical or microbial
       targets in  both primary  and  secondary  habitats (sediments) over longer time periods
       (multi-year). Although this may be a longer term goal, eventually all methods that appear
       to be  suitable for use regulatory or management-level  decisions will need  such to  be
       examined over time periods sufficiently long so that there is confidence that the desired
       targets do not change, or that changes can be captured and dealt with if they do occur.

    2.  Evaluation of chemical indicators for human sewage (timeline:  2 to 3 years).

       Several possible  chemical markers of sewage have been reported and have the potential
       to be used in a rapid to real-time assessment of source.  Coordinated studies to evaluate
       the performance criteria over multiple labs are needed to implement these assays.

       The following analytes should be included in near term evaluation studies:

          1.   optical brighteners;
          2.   coprostanol; and
          3.   caffeine.
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       At least one multi-laboratroy evaluation study  of optical brighteners is currently being
       developed by individual investigators (Hartel et al., 2007).

    3.  Continued evaluation of rapid assays for the detection of enterococci in human health risk
       (epidemiological) studies (timeline:  1 year and beyond).

       Rapid detection of current  water quality indicators  are proposed to allow same day
       evaluation of water quality.   To implement these assays,  continued evaluation of the
       health risk relationship is needed.   For qPCR {Enterococcus\  more  epidemiological
       studies from a  range of beach types are needed  before implementation.  Additionally,
       other rapid assays for  enterococci have been  developed  and should be  evaluated in
       upcoming and future epidemiological studies.

       Methods under  consideration for enterococci detection include the following:

             Immediate (timeline: 1 to 2 years):
                 •  qPCR (detection of DNA); and
                 •  TMA (detect!on of RNA).
             Mid-term (timeline: >2 years; require additional performance evaluation):
                 •  IMS/ATP (detection of activity);
                 •  RAPTOR™ (antibody-based detection)5; and
                 •  enzymatic detection.

    4.  Evaluation of  alternate indicator  candidates in  human health risk (epidemiological)
       studies (timeline:  1 year and beyond).

       Potential alternate indicators (i.e., to replace enterococci and E. coli) that  have already
       been vetted for performance criteria should be included in any future  epidemiological
       studies of recreational waters to determine their relationship  with health risk.

       The following indicators should be evaluated within the next two years:

          •  Bacteriodales human specific markers; and
          •  F+ coliphage (antibody).

       Other candidates indicators  should be added for evaluation as they  meet  required
       performance criteria (as listed above)

    5.  Optimization of sampling, recovery, and processing methods for efficient concentration,
       processing and  detection of rapid, alternative or  host specific indicators (Time line:  1
       year and beyond).
    5 http://www.resrchintl.com/raptor-detection-system.html


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       Additional methods need to be optimized for source specific microbial targets.  Studies
       should address issues such as optimization of sample  volume, processing/concentration
       methods, and extraction/purification methods (especially for targets expected to occur at
       low numbers in the environment).

       Furthermore, research addressing straightforward techniques to enumerate Enterococcus
       faecium  and  faecalis,  rather than the  larger Enterococcus  group that is  presently
       measured, are needed as the individual  species are more likely to  be associated with
       human sewage/feces.  Performance-based criteria tests are also needed for these species.

References

Blanch, AR;  Belanche-Munoz,  L; Bonjoch, X;  Ebdon, J; Gantzer, C; Lucena, F; Ottoson, J;
Kourtis,  C;  Iversen,  A;  Kuhn,  I; Moce, L;  Muniesa, M;  Schwartzbrod,  J; Skraber,  S;
Papageorgiou, GT; Taylor, H; Wallis, J; Jofre, J. 2006. Integrated analysis of established and
novel microbial and chemical methods for microbial source tracking. Applied and Environmental
Microbiology 72(9): 5915-5926.

Griffith, JF; Weisberg, SB; McGee, CD. 2003.  Evaluation of microbial source tracking methods
using mixed fecal sources in aqueous test samples. Journal of Water and Health 1:  141-151.

Hartel, PG; Hagedorn, C; McDonald,  JL; Fisher, JA; Saluta, MA; Dickerson, JW, Jr.; Gentit,
LC; Smith, SL; Mantripragada,  NS; Ritter, KJ; Belcher, CN.  2007. Exposing water samples to
ultraviolet light improves fluorometry for detecting human fecal contamination. Water Research:
In press.

Noble, RT; Weisberg,  SB; Leecaster,  MK; McGee, CD; Ritter, K; Walker, KO; Vainik, PM.
2003.  Comparison  of  beach bacterial  water  quality  indicator  measurement  methods.
Environmental Monitoring and Assessment: 81: 301-312.

SCCWRP (Southern California Coastal Water Research Project). 2007. Beta Testing of Rapid
Methods for Measuring Beach  Water  Quality.  Technical  Report  506.  Available at:
ftp://ftp.sccwrp.org/pub/download/PDFs/506_beta_testing.pdf.

Stewart,  JR;  Ellender,  RD;   Gooch, JA;  Jiang,  S;  Myoda,  SP;  Weisberg,  SB.  2003.
Recommendations for microbial source tracking: Lessons learned from a methods comparison
study. Journal of Water and Health 1: 225-31.

Stoeckel, DM; Mathes, MV; Hyer, KE; Hagedorn, C; Kator, H; Lukasik, J; O'Brien, TL; Fenger,
TW;  Samadpour, M;  Strickler, KM; Wiggins, BA. 2004. Comparison  of seven protocols to
identify  fecal  contamination  sources  using  Escherichia coll. Environmental Science and
Technology 38: 6109-6117.

Stoeckel, DM; Harwood, VJ.  2007.  Performance,  design and analysis in microbial source
tracking studies. Applied and Environmental Microbiology 73(8): 2405-2415.
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US EPA (U.S. Environmental Protection Agency).  1986. Ambient Water Quality Criteria for
Bacteria-1986. EPA440/5-84-002. Washington, DC: US EPA.

US EPA. 2003. EPA Microbiological Alternate Test Procedure  (ATP) Protocol for Drinking
Water, Ambient Water, and Wastewater Monitoring Methods - Guidance. EPA-821-B-03-004.
Washington, DC: US EPA.

WHO   (World   Health  Organization).   2003.  Guidelines for  Safe  Recreational  Water
Environments. Volume 1 Coastal and Fresh Waters. Geneva, Switzerland: WHO.
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                               CHAPTER 4
     COMPARING RISK (TO HUMANS) FROM DIFFERENT SOURCES
      Dennis Juranek, Chair, Centers for Disease Control and Prevention (retired)
      Rebecca Calderon, USEPA
      Jack Colford, University of California, Berkeley
      Elizabeth Doyle, USEPA
      Graham McBride, National Institute of Water and Atmospheric Research, New Zealand
      Samuel Myoda, Delaware Department of Natural Resources
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4.1    Introduction

Fresh and marine recreational waters and beaches may be impacted by human  and/or animal
feces  from point and non-point sources.  Studies have  recently been completed by  EPA on
assessing rapid water quality indicators and their ability to predict swimming-associated illness
at freshwater beaches  impacted by publicly (and  privately)  owned  (sewage/wastewater)
treatment works  (POTW) systems.  Similar EPA studies are currently planned (starting summer
of 2007) to assess the risk of illness for people who swim in marine recreational waters impacted
by POTW systems (point sources of fecal  contamination). Thus,  in the near future additional
information should be available  on risk of illness for bathers at marine beaches largely impacted
by human sewage. Plans are also underway by the Southern California Coastal Water Research
Project to assess swimming risks at least one marine beach that is impacted by non-point source
sewage  that likely contains a mixture of human  and animal feces. However, there remains a
paucity of data on the risk of illness for swimmers at beaches exclusively (or primarily) impacted
by feces from animals.  The absence  of such data makes it difficult to interpret the health
significance of the frequent and persistent elevated fecal indicator levels in such waters that have
been attributed to animals in many locations throughout the United States.

It is widely believed that human feces pose a larger health risk than animal feces to swimmers
and other primary contact recreational water users.  This belief derives from the basic concept
that virtually all enteric pathogens of humans are infectious to other humans, while relatively few
of the enteric  pathogens of animals  are infectious to humans.  Possible exceptions are bird flu
virus  and swine hepatitis E virus (HEV). Workgroup members regarded the evidence for swine
HEV  transmission by  water to be very weak and felt that it could disregarded in terms of risk
assessments during the next 2 to  3 year EPA planning period.  Bird flu was discounted as a major
concern for swimmers because it was felt that if an outbreak of bird flu was recognized in birds
or humans in the United States, early public health recommendations would include directives
for people not to swim in waters that  might be impacted by bird or human  feces, including
chlorinated public pools.

Counterbalancing the concept that animal feces may pose a lower risk is recognition that animals
do harbor many bacterial and protozoan pathogens that  pose  a human health hazard  and that
some  of these pathogens,  such as  enterohemorrhagic  E.  coli  (EHEC), can cause serious,
potentially  life-threatening  illness in humans.   In addition,  animal  feces are  often directly
deposited  in  freshwater  that receives  no  treatment  before reaching bathing areas.   The
concentration of both feces and pathogens may be sufficiently high at beach locations at various
times to pose a significant health risk to swimmers.

The bottom line is that there are few data to demonstrate whether animal feces pose  a lower,
greater,  or equivalent health risk to bathers than human feces. If there is a difference, it would be
helpful to know the magnitude  of that difference in order for  EPA to make appropriate public
health recommendations.  The only  way to get a better sense of the health risk for swimmers
posed by animal  feces is to conduct targeted  studies. Some types of studies  (epidemiological and
quantitative microbial  risk assessment [QMRA] studies) would produce quantitative estimates of
risks while others (fate and transport, pathogen loads in  water, etc.) would provide supporting
information or stand alone qualitative information about risk.
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It is recognized that there are many different types of animals and that the pathogen risks posed
by feces from these animals are different.  These differences, as well as the different pathways
(point, non-point, fecal deposition on land versus in water, etc.) that feces reach bathing areas,
have to be taken into account in weighing risk. Workgroup members approached the issue by
developing Table 5 in order to rank the likely risks from different sources of fecal contamination
and to help prioritize which bather/animal-fecal-risk interface  studies should be undertaken first.

The initial workgroup member discussion focused on assessing the universe of pathogen sources
of interest to recreational waters.  Workgroup members developed a table (Table 5) in which the
major sources of fecal  contamination categories  are in rows.  The major rows  are  wildlife,
agricultural animals, domestic animals (pets), human/sewage, and what the workgroup termed
"secondary environments" (i.e., soil, sand,  and sediments). The wildlife row is subdivided into
aquatic birds and all  others.  The agricultural animals are divided into poultry and other (largely
comprised of domestic livestock such as cattle, sheep, and pigs). The human/sewage is divided

         Table 5.  Comparing Risks (to Humans) from Different Pathogen Sources.3
Source
Viruses Protozoa
Bacteria
Wildlife
Aquatic birds
Other (e.g., deer)
N L
N M
L-M
M #2 priority
Agricultural animals
Poultry
Other (e.g., cattle, sheep)
N N
N M
M-H
M-H #1 priority
Domestic animals
Pets (e.g., dogs, cats)
Fecal shedding by bathers
Adults
Children
N L

L L
H H
L
#3 priority
L
H
Sewage
No treatment (combined sewer
overflows)
No treatment (separate storm
sewer overflows)
Secondary treatment**
Plus chlorine**
Plus UV
Secondary environments***
H H
7* 7*
H H
H H
M-H
(L with
increased
energy)
L L
a Does not have an explicit fate and transport component
* Risk largely depends on amount of human feces present
** Focus of most (U.S.) recreational water epidemiological studies
*** Sediment suspension and contact with beach sand
N = estimated no or negligible risk, L = estimated low risk, M
H = estimated high risk
H
7*
M
L
L
M
= estimated medium risk,
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into untreated sewage, secondary treatment sewage, chlorinated sewage, and UV-treated sewage.
Fecal shedding by bathers (adults and children) is considered separately.

The columns are defined by broad microorganism groups of viruses, protozoan and bacteria. By
an expert opinion process (within the workgroup) each cell of the table was given a risk estimate
of  no (zero) or negligible  risk (N), low,  medium,  and high (L, M, H).   The  types of
characteristics discussed included infectious dose, numbers of pathogens per gram of stool from
infected animals, implication  of source in waterborne disease (extended discussion on foodborne
disease and vector-borne disease), persistence and  survival in the environment and finally an
assumption that sources are in close proximity to a primary contact recreational area.  The N, L,
M,  H risk designations in the table cells represent the workgroup's "best guesses" and assumed
that animal feces was deposited in freshwater relatively closed to bathing sites.  The workgroup
did not  specifically  address pathogen  "die-off associated  with  fecal  deposition  on land
(spring/summer temperatures  resulting in pathogen drying,  transport from soil to water affects on
viability, etc.).  It was felt that many of these types of data are available and that the table could
be updated with real data at a later date as a separate project. It was recognized that updating the
table with published data might change the values in one or more risk rankings of the table cells.

With rare exception, viruses are species-specific.  Essentially, all enteric oral/fecally transmitted
viruses that infect humans are of human origin. For all of the animal viral sources of pollution,
the viral cells were given a zero or negligible risk (indicated by "N" entries in Table 5).  All the
human sources were given  a  high risk estimate with the exception of UV-treated sewage.  UV-
treated sewage at current levels has up to a 0.5-log reduction of viruses and hence this cell was
assigned  a medium risk. More energy intensive UV irradiation may provide up to a 4-log viral
reduction  and result in a low  risk ranking. Sentinel viruses for this group include enteroviruses,
hepatitis  A virus, norovirus,  rotovirus, and adenoviruses.  The major protozoan pathogens of
concern are Giardia and Cryptosporidium.  Given the current knowledge of infectious dose, the
long survival in the environment, many of the animal cells within the table were given a low,
low-to-medium,  or medium risk level.  As with the viruses, all the human cells  within the table
were given a high risk rating with the exception of UV-treated sewage.  The bacteria had similar
ratings to the protozoa ranging  from low-to-medium and again, the human sources were all
assigned  a high ranking with  exception of chlorine- and UV-treated sewage that received a low
risk ranking.

Bather density was divided into adults and children (recognizing that children could be divided
into specific age groups) with the assumption that hygiene and accidental fecal discharges were
much more likely to occur in children than adults.  Thus, for adults, a low risk ranking was
assigned across the columns and a high risk ranking was assigned for children.

Based on  the few studies done on secondary environments, viruses and protozoa were given a
low risk rating, while bacteria were given a medium rating.
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In developing Table 5, workgroup members noted the following discussion points:

    1.  Current epidemiological literature suggests that the symptomatic profile of swimming-
       associated illnesses indicates primarily viral illnesses.
    2.  Certain pathogens such as EHEC have a low probability of occurrence but are associated
       with severe a health outcome.
    3.  Information available to the workgroup suggested that nonhuman fecal sources impacted
       freshwater sources more than marine water sources.
    4.  Combined sewer overflows (CSOs) were considered as untreated sewage.
    5.  Separate  storm sewer  overflows initially were put in the  domestic animal row but
       subsequent discussion  of  recent  studies suggested that they could  have  a  human
       component in many communities.

In discussing the future research needs related to the development of new or revised recreational
water quality criteria, the workgroup members defined the ultimate goal to be  a determined
quantitative risk estimate for each fecal source (row).  The benchmark by which risks should be
compared is the secondary and chlorine treated sewage row that is currently the focus of recently
completed  EPA National Epidemiological and Environmental Assessment  of  Recreational
(NEEAR) epidemiological studies for freshwater and the planned marine water  studies.  The
following research projects  were suggested to meet that objective of determining a sound and
defensible risk estimate for each row of Table 5.

4.2     Summary  of Workgroup  Discussions and Reflections  on  Workgroup-specific
       Charge and Questions

The charge to the workgroup was to consider the impact of waterborne pathogens from various
sources,  both  human and  nonhuman,  on the  health risk  resulting  from exposure to  fecal
contamination in recreational waters. Workgroup members considered the impact of the issue on
beach  monitoring  and notification  and the classification  of waterways as  impaired.  The
discussions were wide-ranging.  Discussions began with the consideration of the relationship of
likelihood of illness due to  nonhuman sources to likelihood of illness  predicted by the use of
epidemiological data from human exposure to POTW-impacted waters using  fecal indicators.
Possible approaches to modifying the application of regulatory approach using considerations of
infectivity to pathogens among species were debated. The location of fecal sources relative to
the  site of monitoring and the potential of animals to move off-site were also discussed. These
topics are all reflected in the potential research activities proposed and discussed  in  this chapter.

Six charge questions  were provided to the workgroup  (see  Appendix A) to help  stimulate
discussion, and to identify key issues for consideration.  A brief synopsis of responses to the
questions is presented below.

•   Question 1:  Is setting  criteria based on a  treated human point source such as a POTW
   protective, under-protective or overprotective of other potential sources of human pathogen?
    Why or why not? Are there data to support this conclusion?
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Whether the criteria  are protective would depend on the effectiveness of treatment in reducing
the levels of pathogens and the relative reduction in indicator organisms. Secondary wastewater
treatment with chlorination could provide a false sense of security for protozoa and viruses.  This
reflects the higher degree  of effectiveness of chlorine in killing/deactivating bacteria  relative to
viruses and protozoa.  Given that current indicators are bacteria and would be reduced to a
greater extent than viruses and protozoa, low indicator levels might suggest that waters impacted
by  POTWs were  relatively pathogen-free when they still contained  a significant  virus  and
protozoan load.   Data are available to  characterize  the relative effectiveness of disinfection
techniques across classes of waterborne pathogens and indicator organisms.

•   Question 2:   Based on the  "state of the  science," what conclusions  or assumptions are
    reasonable to make about risks to humans exposed to human fecal contamination, non-point
    source  contamination from  animal  sources,  and mixed sources  (e.g.,  combined sewer
    overflows [CSOs] and (separate) storm sewer overflows)?6

Workgroup members felt  that it is reasonable to assume that exposure to  fecal contamination
from untreated human waste posed the highest risk.  Treated sewage was judged to be of lower
concern, although it was  more  similar in risk to untreated  human waste than  to nonhuman
sources.  In general, treated and untreated sewage should be treated similarly for the purposes of
evaluating  risk.   Discussion  of CSOs led to the conclusion that they should be considered
similarly to untreated sewage in terms of public health concern. Although separate storm sewer
overflows were initially  considered to  be similar  to  animal waste  in nature, there was  a
recollection of data in the literature  (Haile et  al.,  1999)  noting the occurrence of a significant
occurrence of human pathogenic viruses in stormwater  effluent  and associated  health effects
merits further investigation. Aquatic avian sources were considered to be of low public health
concern. Other wildlife and agricultural  animal (including poultry) feces were deemed to be of
moderate concern.

•   Question 3:  To what extent is it reasonable  to apply risk estimates from  POTW-influenced
    beaches to non-POTW beaches?  Do we understand scientifically whether  this would lead to
    overprotection? What science would be important to understanding this?

A portion of the answer to this question is reflected in the responses to Questions 1 and 2 above.
The propensity to over- or under-protect  would depend upon  the source of the waste impacting
the site.  Non-point sources that largely reflect nonhuman sources of fecal contamination would
probably be overprotected by studies in POTW-impacted locations.  Mixed  sources or untreated
human  sources may  be inappropriately  characterized  by the POTW-dominated data.    The
workgroup's generalizations are reflected in Table 5.  Addressing the public health significance
of CSOs and separate storm sewer overflows are problematic  because of the site-specific nature
of the extent to which they vary by site characteristics.  Although the importance of dilution of
pathogens and indicator organisms in runoff events was  discussed, no  conclusion was reached
about its significance.
    6 It is important to note that the workgroup was specifically charged (see Appendix A) to address (separate)
storm sewer overflows and not sanitary sewer overflows, the latter of which are often discussed in conjunction with
CSOs and commonly using the acronym "SSO."  For this reason, workgroup members decided to not use  the
acronym SSO anywhere in the chapter.


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•  Question 4: Assess whether there is a possibility of overprotection due to a compounding of
   risks from multiple factors (such as the current definition of gastrointestinal [GI] illness [i.e.,
   no fever]; more sensitive molecular-based methods; assuming that POTW risks = nonhuman
   fecal contamination source risks, etc.).

This question was referred to the Acceptable Risk workgroup (see Chapter 5).

•  Question 5: How should EPA  evaluate risk that may have a low probability of occurrence
   but a significant risk, if it occurs?

This  question  was  considered  by workgroup  members  to  be unlikely to be adequately
represented by completed epidemiological  studies  due to the  low incidence (or detection) of
pathogens that are associated with severe  health outcomes.   However, this important public
health issue might be addressed using quantitative microbial risk assessment (QMRA) methods
or by using large-volume filtration in future epidemiological studies.

•  Question  6:  What are the key data  gaps  and uncertainties needed to support criteria
   development in the near term?

The   research  needs and  their  prioritization   are  presented  in  a  separate  section  (4.4).
Epidemiological studies were given a high priority, with QMRA as an  important  adjunct.
Additional  epidemiological studies were encouraged  by workgroup  members because the data
produced directly measure outcomes of interest (e.g., GI illness) and the data produced are more
directly comparable  to data being obtained for human health  risks at marine beaches largely
impacted by human sewage. Thus, epidemiological  studies were preferred to the extent that they
were possible and were viewed as an anchor for QMRA studies.  However, it was recognized
that  it may be difficult to find freshwater recreational  sites with sufficient bather activity to
provide adequate  sample sizes for  an epidemiological study. If suitable sites cannot be found,
then modeling the risk using QMRA techniques based on available epidemiological information
would provide quantitative risk estimates that  could  help with short-term  decision making on
health risks.  Similarly, if pathogen-source combinations  in Table 5 cannot be conducted, it may
be possible to use QMRA to provide quantitative risk estimates.

4.3    Options for Approaches and Implementation Considerations

The  considerations in the followings section are not applicable to the current U.S. approach (i.e.,
US EPA, 1986; see also Chapter 1) because there is  no way to take into consideration the charge
to this workgroup on comparing risk to humans  of fecal contamination from different sources.
The  following considerations are applicable to both the European Union (EP/CEU, 2006) and
WHO (2003) approaches to criteria development. The sanitary investigations are important for
the topics discussed by this workgroup.  Simultaneous use of multiple indicator organisms or a
tiered approach may be necessary.
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4.4  Research Needs

    1.  Prioritize the next generation of studies.  The purpose of these studies is to (1) revisit the
       ratings using a more through literature review and (2)  gain as much information as
       currently exists on the magnitude of the fecal pathogen source problem across the United
       States.
          a.  Quantify the magnitude of difference in the risk of illness from different exposure
              sources (see Table 5) to see if they are different from POTW-impacted waters.
                  i.  Initial estimate of risk - populate the table with infectious dose data and
                    likely  number  of organisms excreted in stool per gram to  characterize
                    fecal source rank.
                 ii.  Magnitude across the United States
                        1.  Number of impaired waters
                        2.  Number of beaches affected by the sources (number of  affected
                           bathers if available)
                iii.  Identify potential fresh and marine recreational sites for each of the fecal
                    pathogen sources (rows) for future epidemiological studies.   Priority
                    should be given to freshwater sites.
    2.  Identify and  characterize  potential sites for future epidemiological studies  using the
       following sources of information:
          a.  National Pollution Discharge Elimination System (NPDES) - provides location of
              all point source dischargers and their levels of discharge
          b.  CWA §303(d) list and  §305(b) reports
          c.  Sanitary  investigations  and  microbial  source  tracking  to  confirm   site
              characterization
          d.  Compile information (via literature review and/or site-specific) about pathogen
              loads in non-point  source water impacted by all sources  of fecal contamination
              (human and  animal), characterizing with respect to pathogens and indicators in
              freshwater versus marine water.

4.4.1   Epidemiological Studies

Workgroup  members agreed that epidemiological studies are the most  desirable  approach to
define and quantify health risks to humans swimming in fecally contaminated waters.  Although
many epidemiological studies have been previously conducted at point source-impacted beaches,
very few  such studies have been published on non-point  source-impacted recreational waters.
The relationship between current water quality indicators and health outcomes that is currently
used in regulating  beaches was developed  from studies at point source-impacted beaches where
water quality indicator levels correlated with swimming-associated illness (US EPA, 1986).  It is
plausible that the relationship between water quality indicators  and health is different at  non-
point source-impacted sites since  indicator levels may  be high due to animal (e.g., birds, other
wildlife) or other  sources that do not increase the risk of human illness.  Some workgroup
members  felt that it is appropriate  to  conduct epidemiological studies at non-point source-
impacted sites to better define risk and guide future regulations.
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Some workgroup members noted that epidemiological studies cannot be performed in all of the
various types of non-point source-impacted waters for which there is a need to know risk.  In
many of these types of sites, other techniques (such as QMRA) will necessarily have to be used
(see Section 4.4.2).  The choice of the specific sites (beaches, rivers, lakes) in which to conduct
epidemiological  studies could be guided by the risk rankings developed in  Table 5.  These
rankings include the types and concentrations  of pathogens  present,  the number  of  affected
waters across the United States, the number of people who are exposed to such sites, and the
number of sites affected by regulatory restrictions under the CWA §303(d) guidelines.

Two  principal  study  designs have been used in prior beach epidemiological studies—the
randomized controlled trial (RCT) and the prospective observational cohort.  The RCT has been
primarily used in European studies and the observational cohort in many countries.  Workshop
participants discussed the relative strengths and limitations of each study design. With respect to
the issue of health  risks in non-point source-impacted waters, the workgroup members actively
discussed the advantages of each design and felt that each had merit.  Because of the required
sample size (i.e., number of swimmers) is much less for an RCT, workgroup members  could
envision  situations in  which  an  RCT  could  be  employed  in future non-point  source
epidemiological  studies.  Workgroup members  did note that in  the United States it would be
more  likely for such  an epidemiological  study  to receive human  subjects approval if the
enrollment scheme were altered from the RCT that has been used in several European studies.  In
Europe, subjects are typically recruited and enrolled in the studies at sites distant from the beach
and then brought to the study  sites.  Workgroup  members discussed  an alternate design for
consideration in  the United States; specifically, enrolling willing persons who are about to enter
the water and randomizing them to either  swim or not swim that day.  As in all epidemiological
studies, aggressive exposure measurements of the water ingested and measures of water quality
(e.g.,  indicators of  fecal pollution) to which the  swimmer is exposed would be critical.  In non-
point  source  sites  where  adequate numbers of swimmers  could be enrolled, the  prospective
cohort design could be used for epidemiological studies.  Workgroup members felt that it would
be very helpful  at  some point to use both study designs simultaneously  on one beach.   This
would allow for a direct comparison of the results and help guide future epidemiological studies.

    1   Epidemiological studies (highest priority is to conduct studies at beaches impacted by
       different types of non-point sources of fecal contamination [see Table 5])
          a.  Randomized control trials  (for consideration at beaches with  low numbers  of
             bathers)
                 i.  European design should be modified for  use in  the United States
                    (suggestion - randomize people about to swim into groups that will swim
                    or not swim)
                ii.  Potential problem - identifying appropriate numbers of participants may
                    be more difficult for inland (predominantly fresh) recreational  waters than
                    marine waters
                iii.  Estimated necessary sample size - 1,500 people/site
          b.  Prospective observational cohort study
                 i.  Potential problem - identifying sufficient numbers of participants may be
                    more difficult for inland recreational waters than marine waters
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                 ii.  Estimated necessary sample size - 5,000 to 10,000 people/site (200 to 400
                     people/day)
                 iii.  Wide range of exposures needed

4.4.2  Quantitative Microbial Risk Assessment

Several workgroup members  advocated  for  QMRA  studies  in  developing  new  or revised
recreational ambient water quality criteria (AWQC). In part because QMRA can be used to rank
the relative risks of different situations, such  as sites impacted by animal versus human  fecal
wastes, and where no direct epidemiological information is available.  QMRA studies can also be
instructive in recreational areas where such studies have already been completed.

QMRA is increasingly used to characterize risk to humans from exposure to contaminated water
when engaging in  "contact recreation," especially swimming,  but also other forms of water
contact such as water skiing.  It translates the environmental occurrence of pathogens and the
volume of water that individuals are exposed to into a probability of infection or illness. Inputs
with known variability  are described by statistical distributions from which many  random
samples are taken, often using a "Monte Carlo" calculation procedure, to derive a risk profile.7

The following four  step process is used:  (1) identifying the important pathogens ("hazards"); (2)
determining  human  exposures  to  contaminated  water,  via ingestion   or  inhalation;  (3)
characterizing dose-response, using data available from clinical trials, illness surveillance, and
outbreak data;  and (4) mathematically characterizing  the risks and  communicating risks and
attendant uncertainties.

For step 1, a suite of sentinel pathogenic microorganisms should be considered for each situation
as they are considered to cover the range of illnesses that could arise in the United States, such as
the following:

    •  viruses   -  norovirus,   Hepatitis  A  virus,   caliciviruses,   enteroviruses,  rotavirus,
       adenoviruses;
    •  bacteria - EHEC, Campylobacter spp., Salmonella spp., Shigella spp.; and
    •  protozoa - Giardia cysts,  Cryptosporidium oocysts.

The setting for each site of interest will dictate which  of these pathogens should be used.  For
example, a recreational site impacted only by animal wastes should not need to include viruses.
Adenoviruses will need to be included where aerosols may  be inhaled (e.g., by water skiers).

For  step 2, information  on water ingestion and  exposure rates, along with  duration of the
recreational activity, are combined  with the concentration  of pathogens in the water to  obtain a
    7 EPA's Office of Water has developed a "complete draft" of a Protocol for Microbial Risk Assessment based
on the  EPA-ILSI (ILSI,  2000) Revised Framework for Microbial Risk Assessment (http://www.ilsi.org/file/
mrabook.pdf) and which is consistent with the chemical risk assessment paradigm.  The Agency has initiated a
review to insure it meets risk assessment needs for all water-based media. Contact Stephen Schaub, EPA Office of
Water (see Appendix B), for information on the Protocol for Microbial Risk Assessment.
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dose—all these variables being described by statistical distributions.  Information on the origin,
quantity, and fate and transport of wastes deposited on a land surface and into waterways is of
prime importance in determining the distributions of pathogens in the water that is subsequently
ingested or inhaled.

For step 3,  several dose-response analyses have been reported and may be used, albeit with
caution. In particular, the form of the "dose" used in a clinical trial needs to be made consistent
with the form used to describe the  dose ingested or inhaled.8  Also, uncertainty in the dose-
response equation, in the form of credible intervals, can be captured by the calculation process.

In step 4, risk profiles may be derived, in the form of a cumulative distribution function—this
will be  particularly useful  for examining the  risks associated with rare but  highly significant
illness (e.g., EHEC).  This also enables uncertainty measures to  be  calculated.  Comparing
relative  risks for different sites  should be done by comparing risk profiles, rather  than by
comparing single risk "numbers."

    1.  QMRA provides a range of possible illnesses or risks, allows comparisons across all fecal
       pathogen sources (see Table 5), and number of illnesses by a modeling  approach  (highest
       priority is to conduct assessments at beaches impacted by different types  of non-
       point sources  [see Table  5]).   There was discussion among workgroup members
       regarding  the strengths and  limitations of conducting QMRA  versus epidemiological
       studies (see Eisenberg et al., 2006); QMRA:
          a. Is a potential alternative, adjunct, or precursor to epidemiological studies
          b. Can evaluate infection and illness
          c. Could evaluate sentinel (index) pathogens such as:
                  i.  Bacteria (EHEC, Campy lobacter, Salmonella, Shigella)
                 ii.  Protozoa (Giordia, Cryptosporidium)
                iii.  Viruses  (norovirus, Hepatitis  A, caliciviruses, enteroviruses, rotavirus,
                    adenoviruses)
          d. Can consider inhalation as an additional route of exposure if data are available
                iv.  Adenoviruses
   2.  QMRA is a good way to compile information (via literature review and/or site-specific)
       about pathogen loads in source waters  impacted only  by animal  sources  (with an
       emphasis on freshwater) and to characterize pathogens and indicators.

4.4.3   Etiologic Agents

Workgroup  members felt it important to emphasize that there is a glaring lack  of knowledge
about the incidence with which  specific pathogens cause  swimmer-associated illnesses at both
non-point source- and  point source-impacted beaches. Identification of such pathogens as the
actual cause of illness in swimmers would provide important information for developing new or
    8 For example, a rotavirus clinical trial will report dose as FFU (focus forming units); there may be many virus
particles for each FFU.


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revised recreational AWQC  (or State Water Quality Standards) to enhance the protection  of
public health.  In order to go forward with currently available technologies, the diagnosis  of
viruses could be made by exclusion of bacterial and protozoan  pathogens causes of illness.
Additionally,  such information would be essential inputs into QMRA models to be used  at
recreational sites (or types of sites) where epidemiological studies cannot be conducted due  to
expense  or insufficient numbers of swimmers.  Because advances  in modern  techniques  in
microbiology  now make  a more  complete  identification of specific pathogens  possible,
workgroup  members  felt that the epidemiological studies  currently underway  and planned
provide a unique opportunity to collect specimens (stool, saliva, and/or blood) from swimmers
(and non-swimmers as controls) with which to identify  the responsible waterborne pathogens.
Such  data would be complementary to the data collected in studies of pathogen occurrence  in
water that are presented elsewhere in this chapter and these proceedings. Workgroup members
suggested that both types of pathogen occurrence information (in humans, in water) be collected
during future epidemiological studies in order to minimize cost and maximize the utility of the
information.

    1.  Identify etiologic agents of swimming-associated illness.
    2.  Pilot approaches for identifying etiologic agents in planned and ongoing epidemiological
       studies.
    3.  Classify  etiologic  agents in ill swimmers  by broad groupings (i.e.,  viral,  bacterial,
       protozoan).
    4.  Develop and evaluate  sample collection techniques (stool, salivary antibodies, blood).

All of the above could be done as an adjunct  to epidemiological studies.

4.4.4   Fate and Transport

Because direct pathogen detection is  not feasible  on an ongoing basis, a surrogate measure
relating water quality conditions to human health risk is  required.  When developing the
appropriate indicator(s)  to  use in  this  approach,  knowledge  of  the  fate and  transport
characteristics of the  pathogens and indicator(s), both individually and as they relate to each
other is critical.

Individually, fate and transport is significant because only those pathogens that are present and
viable in a given waterbody pose a potential public health risk. These pathogens are typically
divided into the following three major categories: viruses, bacteria, and protozoa. Because the
microbiological  characteristics of each of  these groups are significantly  different, it is not
unreasonable  to  assume  that their fate   and transport characteristics will  vary  (perhaps
significantly) as well.

The most  simplistic route of pathogen transport is direct  deposition.  Once  the pathogen(s)
(assumed to be carried in the feces of warm  blooded mammals) is excreted over or in the water,
the question is twofold—how long will the pathogen be viable  and available (i.e.,  persist in the
water column).
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Indirect deposition of feces introduces a more complex situation.  First, the fecal properties of
different mammals can vary substantially.  One of the primary differences (aside from pathogen
and indicator density) is moisture content.  That is, very "wet" feces is more likely than "dry"
feces to introduce pathogens into the aquatic environment.  After defecation, the distance of the
feces from surface water plays an important role as well. Driven by precipitation and transported
primarily via surface runoff, the pathogens are typically washed into the surface water either by
sheet flow or are collected and discharged through a storm water collection system. During this
transport, they are subjected to a variety of environmental factors—including, but not  limited to,
UV disinfection, predation, temperature—that affect the proportion that will ultimately end up in
surface water in which people are recreating.

Another category of indirect deposition includes point source discharges, such as POTWs, CSOs,
concentrated animal feeding operations (CAFOs), and other NPDES permitees.  In addition to
the issues identified above, the effect of the treatment processes that these effluents are subjected
to plays a role in fate and transport of the pathogens.

Resuspension from sand, soil,  or sediment  (i.e., secondary environments) can  also  play an
important role in pathogen fate and transport.  There may be a reservoir of indicator(s) and/or
pathogens that could be reintroduced into the water column. Additionally, regrowth of either the
indicator(s)   or  pathogens   could   represent   a   source  and/or   confound   the  risk
assessment/prediction.

Ideally,  the  indicator(s) chosen as the  surrogate for the pathogens  will have the same fate and
transport characteristics of the pathogens themselves.  However, since this is unlikely, it is
important to know  and relate the characteristics that are  specific to the indicator(s)  and the
pathogens so that the measurement of the indicator can be correlated to the concentration of the
viable pathogens in the water and ultimately to public health risk.

A number of studies  have been published on  the  fate and transport of many waterborne
pathogens  and current indicator organisms.  Therefore, a literature review to identify any data
gaps so that additional studies may be designed and also to inform QMRA studies would also be
useful.

    1.  Conduct fate and transport studies for indicators and sentinel (index) pathogens.
   2.  Conduct literature review to identify data gaps and to inform QMRA.
   3.  Identify indicators that have the similar fate and transport characteristics as pathogens.
   4.  Should include assessment of risk of pathogens and indicators being resuspended from
       sand, soil, and sediments (secondary environments).

4.4.5   Determine the Occurrence of Pathogens  in Impacted Recreational Waters

The pathogen occurrence and pathogen concentrations in water impaired by animal feces in one
or more non-point study site(s) (e.g., beach impacted by [non-CAFO] agricultural animal runoff;
Table 5,  priority #1) could be compared with pathogen load in planned POTW-impacted marine
epidemiological  studies.  It is  also proposed  that investigators consider using  high-volume,
tangential-flow water filtration methods that were recently developed for assessing bioterrorism
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threats to drinking water.  This technology was designed to  simultaneously capture very low
concentrations of viruses, bacteria, and parasites in 10 to 100 L of water using a single collection
apparatus (filter and pump).  Although the equipment and pathogen recovery methods  were
initially designed to work on finished drinking water, there has been additional research to adapt
the process for use on raw water supplies.  The raw water application of this technology may be
sufficiently understood for its employment in current or planned studies within the next 2 to 3
years.  If the methods have not yet been adequately evaluated for this purpose, EPA may wish to
encourage fast tracking their development for use in recreational water epidemiological and
related field studies.  Use of the  large volume filtration tools might also be helpful to assess risks
associated with low probability events that have serious health consequences (e.g., EHEC).

    1.  Determine the occurrence of pathogens in affected waters using the high volume filtration
       currently being developed for counter bioterrorism purposes.

4.4.6   Bather Studies

Bathers themselves can be a source  of both indicator organism and  pathogens in  recreational
waters (Elmir  et al., 2007). Workgroup members suggested the following studies to determine
the magnitude of this problem and/or the conditions at recreational sites in which this would be a
problem.

    1.  Conduct additional studies on the impact of bathers on  levels of indicator organisms and
       as a source of infectious pathogens for other bathers.
    2.  Develop better tools for assessing bather density.
    3.  Incorporate bather density into the study design and analysis of future recreational water
       epidemiological studies.
    4.  Conduct additional studies  on human  shedding in a controlled setting with a focus on
       young children.
    5.  Incorporate bather contribution to indicators and pathogens in QMRA studies.

4.4.7   Additional Research (Either Short-  or Long-term  Depending  on  EPA  Priority-
       setting)

The following research would also enhance many of the ongoing and future  efforts described in
this chapter and elsewhere in these proceedings.

    1.  Include epidemiological  data in predictive modeling efforts.  This would broaden the use
       of both epidemiologic and modeling data.  Many recreational epidemiological studies
       collect an extensive set of environmental data.  Whether this is sufficient to accomplish
       environmental modeling  is unknown.  Both modelers and epidemiologists should discuss
       the feasibility of this effort.
    2.  Develop a method for  accurate  exposure assessment among  swimmers.    Exposure
       assessment in terms of water  contact and quantity of water swallowed or inhaled  is an
       area of potential misclassification in observational epidemiologic studies. The following
       would improve exposure assessment in epidemiologic studies:
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          a.  Develop individual sampling devices.
          b.  Develop methods and conduct studies to determine the quantity of water ingested
             and inhaled in recreational settings.  Consider studying secondary recreational
             contact for potential comparison.

References

Eisenberg, JNS; Hubbard, A; Wade, TJ; Sylvester, MD; LeChevalier,  MW; Levy, D; Colford,
JM, Jr. 2006. Inferences drawn from a risk assessment compared directly with a randomized trial
of a home drinking water intervention. Environmental Health Perspectives 114:  1199-1204.

Elmir, SM; Wright,  ME;  Abdelzaher,  A;  Solo-Gabriele, HM; Fleming,  LE;  Miller, G;
Rybolowik, M; Shih, M-TP;  Filial,  S; Cooper, JA; Quaye, EA. 2007. Quantitative evaluation of
bacteria released by bathers in a marine water. Water Research 41: 3-10.

EP/CEU (European Parliament/Council of the European Union).  2006. Directive 2006/7/EC of
the European Parliament and  of the Council of 15 February 2006 Concerning the Management of
Bathing Water Quality and Repealing Directive 76/160/EEC. Official Journal of the European
Union L64: 31-51. Available  at:
http://europa.eu.int/eurlex/lex/LexUriServ/site/en/oj/2006/l_064/l_06420060304en00370051.pdf.

Haile, RW; Witte, JS; Gold,  M; Cressey, R; McGee, C; Millikan, RC; Glasser, A; Harawa, N;
Ervin, C; Harmon, P; Harper, J; Dermand, J; Alamillo, J; Barrett, K; Nides, M; Wang, GY. 1999.
The  health  effects  of swimming  in ocean  water contaminated  by  storm drain  runoff.
Epidemiology 10(4): 355-363.

ILSI (International Life Sciences Institute Risk Science Institute). 2000. Revised Framework for
Microbial Risk Assessment. Washington, DC: ILSI.

US EPA (U.S. Environmental Protection  Agency). 1986. Ambient Water Quality Criteria for
Bacteria-1986. EPA440/5-84-002. Washington, DC: US EPA.

WHO (World   Health  Organization).   2003.  Guidelines for  Safe   Recreational  Water
Environments. Volume 1 Coastal and Fresh Waters. Geneva, Switzerland: WHO.
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                                 CHAPTER 5
                             ACCEPTABLE RISK
   Paul Hunter, Chair, University of East Anglia, U.K.
   Michael Beach, Centers for Disease Control and Prevention
   Lora Fleming, University of Miami School of Medicine and Rosenstiel School of Marine
     and Atmospheric Sciences, Florida
   Peter Teunis, RIVM (National Institute of Public Health and the Environment), Netherlands
   Timothy Wade, USEPA
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5.1    Introduction

This workgroup was primarily charged to reassess the extent to which existing microbiological
criteria protect the health of swimming populations, and whether or not this is appropriate for
current U.S. society.  In particular, the  workgroup was asked to consider the case of vulnerable
(susceptible or sensitive) subpopulations and whether current levels of public health protection
are sufficient for these people.  The workgroup was also asked to consider whether it would be
possible that improvements in recreational water quality criteria would be sufficient to improve
public health protection for drinking water, recreational water, or consumption of shellfish.

Group members decided to organize the main questions under the following headings:

    •   Whether the term "acceptable risk" is still the most appropriate term.
    •   Public involvement in "acceptable risk" decisions
       o  To whom should any risk from recreational water contact be "acceptable"?
       o  How can we get public involvement in the decision making process over what is and
          what is not "acceptable"?
       o  How best to communicate risk with and educate the  general public about risks from
          recreational water.
    •   "Acceptable risks" to the general population
       o  Whether the current methods for assessing risk from recreational water exposure are
          sufficient  and if not, what new methods may be appropriate?
       o  Whether risks differ between marine and freshwaters and whether it is "acceptable" to
          have different levels of protection for people bathing in these different waters.
       o  Whether the current approach,  based on protecting people from enteric illness is
          sufficient, or whether  "acceptable  risk" decisions need to take  into  account  non-
          enteric illness.
       o  Whether risks are different to people swimming in tropical, subtropical and temperate
          waters.
    •   "Acceptable risks" for vulnerable subgroups
       o  Define the main vulnerabilities.
       o  Determine what  risks are  greater in vulnerable subgroups  and whether general
          recreational water standards  are sufficient to protect these groups.
    •   What are the current levels of protection from existing criteria?
    •   Potential synergies for health protection between revised recreational water criteria and
       standards for drinking water and shellfisheries.

5.2    Main Conclusions and Observations

5.2.1   Whether the Term "Acceptable Risk" is Still the Most Appropriate Term

There was commonality amongst the  workgroup  members  that the term "acceptable risk" is
flawed and should be avoided during the process of creating recreational water criteria.  The term
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"acceptable"  was  felt to elicit responses  related to "acceptable to whom?" and  had  the
connotation that swimmers accepted the risk and there was some level  of informed decision
making during the process.  Although a variety of suggestions for replacing "acceptable" were
elicited (e.g.,  tolerable,  appropriate,  excess, increased),  no agreement  on  terminology  was
reached.  However, workgroup members felt that any new term  should be simple, easily
understood, and inclusive rather than paternalistic in nature.  Workgroup members also felt that
EPA should develop a policy that includes public  interaction during the  criteria development
process.

This approach to determining "acceptable risk" should be broadly inclusive of impacted groups
(e.g., swimmers, taxpayers who pay for beaches to be open) throughout the process. This would
mean that EPA's decision making and criteria development process should include information
on how impacted groups would determine the level of "acceptable risk" and how those risks and
the concept of protective criteria would be best communicated.  This would require that EPA's
criteria development process (1) be clear, transparent, and communicated to all stakeholders; (2)
factor in and include input and data collected from impacted groups; (3) include a data-informed
communication package to educate impacted groups when the new criteria are released; and (4)
develop a plan for assisting state and local authorities with future communication of the concepts
of "acceptable risk" and  the meaning of beach closures and advisories to  the public.  Such an
effort would require collaboration with sociologists and anthropologists to assess risk perception
and risk communication research and apply this to development of appropriate assessment tools
for determining key elements necessary for criteria development, release, and interpretation.
Rapid integration of this information into ongoing EPA criteria development would be  expected
to build or improve partner involvement and acceptance of the new criteria.

5.2.2   Public Involvement in "Acceptable Risk" Decisions

Including public involvement in the criteria setting process would require that impacted groups
are first informed about the process and then information solicited about how these groups make
"acceptable risk"  decisions  and how tolerant these groups  would be of risk associated with
recreational swimming area use. Key research questions include the following: (1) What does
the public  understand  currently? (2) What does  the public  think of when one uses  the term
"acceptable  risk"?  (3)   How  does   the  public interpret  existing   criteria  and  beach
closures/advisories? (4) How does/should EPA communicate this risk? and (5) What level of risk
would  the public accept? The voluntary nature  of recreational swimming needs to be clearly
explained and put in context with other routinely and voluntarily accepted risks (e.g., driving to
the beach, eating  at  local  restaurants, smoking).   The breadth of illness associated with
swimming and types of illness to be reduced by new or revised recreational water quality criteria
needs to be clear.  Workgroup members felt that current criteria were not well understood by the
public  or beach managers so that indicator cutoff values (i.e., beach closures) connoted zero risk
and "safe" water rather than an understanding of the concept of "acceptable risk." These groups
should be  allowed  to  provided input  on factors used in the  decision making process (i.e.,
reduction of illness in children being a decision  point).  Workgroup members appreciate that
EPA will ultimately be making the decisions and setting criteria but felt that a more informed
and communicative path for this decision making is critical to future acceptance of these new or
revised criteria.
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Workgroup members suggested that EPA conduct the following activities:

    1.  Begin building a transparent  communication plan to inform impacted  groups about
       ongoing criteria development.
    2.  Rapidly initiate studies to assess how impacted groups understand and perceive the risks
       associated with  recreational water use and what  level of voluntary risk would be
       "acceptable," followed by evaluation of final communication materials.
    3.  Develop a multi-year plan to communicate the criteria development process to impacted
       groups and a communication plan for educating impacted groups about the new criteria.
    4.  Assist state and local officials in developing data-based risk communication plans for
       communicating information on criteria interpretation and beach closures/advisories to the
       public.

5.2.3   "Acceptable Risk" Levels for the General Population

    Method for Assessing Risk

Workgroup  members identified  epidemiological (both randomized control  and prospective
observational cohort designs) and quantitative microbial risk assessment (QMRA) studies as the
main methods for assessing risk.  Some workgroup members noted that while QMRA is widely
used and relied on by EPA for drinking water applications, it does not seem to be as widely used
for recreational waters (with the exception of the work done by Jeffrey Soller).  To broadly
evaluate  the gastrointestinal  (GI) illness risk associated with the numerous potential pathogens
found in  recreational waters, epidemiological studies were viewed as more appropriate, although
workgroup members believed the EPA should investigate expanding the role of QMRA (see also
Chapter  4).  One distinction noted was  that  although epidemiological studies are  good at
assessing the generally  common and  self-limiting risks associated with swimming in fecally-
contaminated waters, they are not well-suited for investigating rare but potentially severe (and
potentially  life-threatening) illnesses that may be associated  with recreational water exposure
such as enterohemorrhagic E. coli (EHEC). For  these special cases, workgroup members  felt
QMRA approaches may be the best way to assess risk and address potential outbreak situations.

Other cases where QMRA could be useful would be for evaluating specific risks associated with
specific  waterborne  pathogens  (although  not  necessary  rare)  such  as  Cryptosporidium,
Norovirus,  and Shigella. A third method that has not yet been  widely applied to assess risk from
recreational waters is dynamic  infectious disease modeling (with the exception  noted above).
These models are a form of QMRA,  but specifically account for factors such as the immune
status of the population (susceptible, infected, immune), rates of secondary transmission of
illness, and other parameters.

Workgroup  members also  noted  that  epidemiological studies can identify illness,  but  not
infections, whereas QMRA studies can predict infections, but have more uncertainties associated
with translating infections  into an estimation  of illness.  Although epidemiological  studies
provide valuable results, there may be some confusion in their interpretation and application; for
example, most studies of recreational waters to date have been conducted at beaches with known
human sources  of fecal  contamination and results may not apply to other sites.   EPA needs to
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clearly explain the purpose of such studies (current, planned, and previous studies), their focus,
and limitations.

   Marine versus Freshwater

Workgroup members did not see any reasonable rationale for different "acceptable risk" levels in
marine and fresh recreational waters.  Although the  current "acceptable risk" levels based on
EPA's Ambient Water Quality Criteria [AWQC] for Bacteria - 1986 are different for fresh and
marine waters (gastroenteritis rate of 8 per 1,000 swimmers in freshwaters and 19 per 1,000 in
marine waters), workgroup members believed this to  be an arbitrary decision that was not well
founded. Workgroup members agreed that there could be different indicators, or different levels
for the same indicator across marine and fresh recreational  waters, but those levels should relate
to the same  estimate  of risk.   Furthermore, justifying differences in risk to the  public and
stakeholders based on type of water would continue to be confusing and problematic.

There was some  further discussion about how to account for differences in baseline levels  of
illness that could  exist across locales and whether use  of a relative risk scale instead of an excess
(or attributable risk)  scale may be a better way of addressing such differences. There is a distinct
difference between doubling an absolute risk versus doubling a relative risk (see Section 5.2.5).

   Enteric versus Non-enteric

Workgroup members felt that criteria based on pathogen indicator levels  derived to protect
against GI illness would not necessarily protect against all non-enteric illnesses, with the possible
exception of certain upper respiratory illnesses (URIs) transmitted via the fecal-oral route. At
least one study  (Fleisher et al.,  1996) observed  exposure-response relationships  with  fecal
streptococci  (enterococci) and  URI; workgroup members  believed  there  was  potential for
pathogens causing such illnesses (e.g., adenoviruses)  to be transmitted via fecally-contaminated
waters.  The workgroup members  felt that most causes of other non-enteric illnesses (e.g., rash,
earache) were most likely to be caused by environmental or naturally occurring conditions and/or
pathogenic microorganisms unrelated to fecal contamination (e.g., Naegleria infection,  non-
cholera Vibrios) and therefore would not be explicitly controlled by criteria based  on protection
for GI illness (WHO 2003).

There was uncertainty about EPA's role in protecting against such illnesses, particularly  those
that  are not anthropogenic.  However, there are some risks that were unclear.  For example,
cyanobacteria concentrations can be influenced by nutrients and human impact, and may also be
a cause of swimming-associated  skin infections, respiratory infections,  or long-term  chronic
conditions  such as liver cancer (Chorus and Bartram, 1999; Fleming et al., 2002).

Workgroup members felt that  earaches  (otitis externa or  "swimmers ear")  were  probably the
most debilitating of the  commonly  occurring  swimming  associated  non-enteric illnesses.
However, they also felt that there was no  evidence that  such infections (often  caused by
Pseudomonas) were associated with fecal  indicator bacteria, and therefore AWQC or  State
Water Quality Standards based on fecal indicators would not afford public health protection for
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those illnesses.  Workgroup members also felt that other indicator bacteria, or other types of
indicators, are not currently available to protect swimmers from most non-enteric illnesses.

Workgroup  members agreed that  when  a beach was closed due to fecal contamination then
potential non-enteric swimming associated  illnesses would  also  be  prevented,  although  this
would be inadvertent and it is not clear how often or under what circumstances this would occur
(e.g.,  Do   currently used  indicators   correlate  with  the  presence  of  cyanobacteria  or
Pseudomonasl).

    Tropical and Subtropical versus Non-tropical Recreational Waters

Workgroup  members identified the possibility that tropical and subtropical recreational waters
may have to be approached differently from temperate waters because of issues such as regrowth
and significant spatial or temporal variability of both indicator organisms and pathogens in the
water and  soils, substantially different ecosystems and climatic  conditions (including  heavy
rains), and possibly the presence of a greater range of "exotic" pathogens.  In addition, persons
may experience  longer term seasonal exposures in tropical and subtropical recreational waters
due to the warm waters throughout the year.   Finally, it is highly likely that the background rate
of GI diseases is higher in tropical and subtropical populations (Payment and Hunter, 2001).

It is important to note that workgroup members believe that  people in tropical  and subtropical
areas  should not be  exposed to greater health risks from exposure to  recreational waters than
people in more temperate areas.

Relative risk measures, unlike excess risks, express risk as a proportion of baseline risk and thus
correct for varying background levels.  Workgroup members discussed other ways to describe
risk in place of an "acceptable risk" framework, including illnesses prevented as a result of
implementing criteria (as done by the U.S. Food and Drug Administration [FDA]). Workgroup
members felt that there was need for risk communication in this area so that risks are fully and
accurately communicated.

5.2.4   "Acceptable  Risk" Levels  for Vulnerable Subgroups

   Definitions

In considering vulnerable human populations with regards to the  health risks from exposure to
recreational  water,  workgroup  members  distinguished  between two   major categories  of
vulnerability,  (1) persons at different life stages,  and (2) persons with  suppressed immune
function.

    What is Different?

Life stage connotes that for a variety of reasons, humans vary in their level of vulnerability to the
health risks associated with exposure to recreational water over their life span. In particular, the
discussion  focused on the possible increased vulnerability of children,  pregnant women (and
their fetuses), and the elderly.  Workgroup members felt that  children are at a greater increased
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risk compared to all other life stages because of their behavior and possibly because of naive
immune  status.  Because all members of the population pass through life  stages, classifying
childhood as a  life stage instead  of  simply a subpopulation strengthens  the argument for
explicitly considering children when developing AWQC.  Regarding behavior, children probably
have higher exposures; that is, they are  more likely to consume both marine and freshwater.
Moreover, young children have significant hand-to-mouth and fecal-oral behavior that may lead
to the consumption of contaminated  substances.   Very young  children may  also be more
vulnerable to pathogens in recreational waters because they have never been exposed to these
pathogens previously.   Of note, preliminary, unpublished  data from recent studies by EPA
(NEEAR; Timothy Wade, EPA Office of Research and Development,  personal communication,
2007) as well as results from other published studies appear to demonstrate an increased risk of
GI  illness and possibly respiratory illness  for  children from exposure to recreational waters,
although this has not yet been formally reviewed.

Pregnant women (and  their fetuses) and  the elderly may be at increased risk for  more severe
consequences from acquiring GI diseases  from exposure to recreational waters. Pregnant women
and their fetuses may be at greater risk from certain recreational water pathogens (e.g., coxsackie
B  virus  associated  with fetal infection when acquired close to delivery, and  enterovirus
associated with certain fetal malformations).  Furthermore, pregnant women may be at increased
risk for significant dehydration and its consequences if they  do acquire a GI infection resulting
from contact with recreational  water.  Finally, although the elderly were believed to be less
exposed  due to  decreased high intensity swimming  behavior, it might be possible that the
decreased immune function associated with increasing age might make them  more vulnerable to
infection and illness.

Workgroup members also identified a potentially large subpopulation of persons with suppressed
immune  function, ranging from  persons  with HIV/AIDS to  persons undergoing chemotherapy
and using other immunosuppressive medications.  Of note, a portion of the latter subpopulation
could be completely unaware of their suppressed immune function.  As a group, persons with
suppressed immune function would be at increased risk compared to the healthy population of
acquiring diseases from a range of opportunistic pathogens found in recreational waters, such as
Cryptosporidium,  Toxoplasma,  and Vibrio parahemolyticus.    Furthermore,  persons  with
suppressed immune function may be at increased risk of more severe  consequences from these
diseases as well as from the effects of dehydration—a secondary ramification of GI diseases.

Tourists  and visitors were identified by workgroup members as a unique potentially vulnerable
group to increased health risks associated  with exposures to recreational waters. Similar to small
children, these people  may  be previously  unexposed  to the  range  of pathogens in  a new
recreational water environment, and as such,  more susceptible to both acquiring the infection and
disease—possibly with more severe health consequences.  Given that many of these people are
on vacation, they may  experience greater exposure to recreational waters.9   Further, given that
significant tourist travel is to tropical and subtropical areas, there may be additional risks from a
range of exotic pathogens and potentially unique  ecosystem conditions found in  tropical and
subtropical recreational waters.
    9 Tourists may spend long periods of time in the water over several days, whereas local users may have shorter
exposures that are spread further apart.


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Overall, workgroup members believed that the apparent increased risk for children for acquiring
GI and possibly other diseases from exposure to both fresh and marine recreational waters should
drive  the health risk assessment of any future recreational water criteria development efforts,
assuming the current and future research continue to demonstrate their apparent increased risk.
Workgroup members emphasized that future recreational water criteria set on health risks and
exposures of adults would not be sufficiently protective for children. As mentioned previously,
because of differences in susceptibility between adults and children (and other subpopulations as
well)  a given numeric  criteria translates  to different risk levels  for  each  subpopulation.
Therefore, it is impossible to protect adults and children equally.  The workgroup members felt
that data on children should be explicitly  considered for deriving the "acceptable risk" level in
the development of new or revised recreational water quality criteria, with the understanding that
the associated  risk level for adults would then be even lower.

Workgroup members felt that the increased  risk to immunosuppressed people should not be an
important factor in setting any future recreational water criteria because the  factors associated
with the increased risk of  disease  in this  vulnerable subpopulation are not controllable or
achievable through management of recreational water sites. Rather, an emphasis should  be made
on improved risk communication with immunosuppressed groups and health  care professionals
to inform them about risks associated with recreational water use and, in consultation with their
health care provider, assessment of the need to avoid recreational water exposure.

5.2.5   What are the Current Levels of Protection from Existing Criteria?

It is not certain how accurate the current levels of protection are.  "Magic" numbers like 8 or 19
cases  of gastroenteritis in 1,000 swimmers can "take on a life of their own," increasing the risk
of distraction  from  the basic  objective—providing  best effort  to protect  swimmers.   This
provides a compelling reason for not deriving and using a single numeric value for the  targeted
risk for new or revised AWQC. Risk levels from preliminary unpublished data from the EPA
NEEAR study seems  to agree with WHO (2003) B category waters (i.e.,  1  illness per 20
swimmers) (see Table 1, Chapter 1; Timothy Wade, EPA Office of Research and Development,
personal communication, 2007). Pathogens  associated with threshold indicator levels in current
(US EPA, 1986) AWQC may differ from those in 2007; the population established in 1986 also
may have different susceptibility due to differences in immunity to current pathogens  in  1986
versus 2007.   Aside from protection against enteric illnesses, it  seems likely that  enterococci
levels below  current standards also  provide  some protection against upper respiratory  tract
infections.

Instead of absolute levels of risk, workgroup  members felt that the preventable  fraction is a better
measure for the level of protection.  This  includes information on the background level of risk
against which  the risk associated with recreational water use must be compared.  Presence of
other  major  exposure routes  may  mask  any beneficial  effects  of  lowering risks due to
recreational bathing. Thus, an  absolute reduction in illness from recreational  water  may not be
reflected in a similar reduction in total cases  in the community if people simply become infected
by  other transmission  routes.  On the other  hand, disease reduction may be even greater  if
secondary cases are also prevented.  Most  recreational water exposures are  experienced by a
minority of the population who  are repeatedly (chronically) exposed.
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It is also possible that part of the primary contact-associated infections is caused by bather-to-
bather transmission.   This independent, direct fecal  contamination  would be  unaffected by
monitoring programs designed to limit  sewage contamination.  Further  studies are needed to
understand the role of bather shedding in disease transmission and microbial water quality
indicator levels.

In a trade-off situation,  acceptability of  risk is  partially determined by its source; that  is,
pathogen-shedding by fellow swimmers is difficult to control and may be more readily accepted
than contamination by  treated sewage effluent or agricultural runoff, whose risks  are usually
considered less acceptable.  More important than trying to  enforce  compliance with a fixed
standard level of risk, is the need to work  toward continual  improvement in public health
associated with recreational water use.

5.2.6   Potential Synergies for  Health Protection between New or Revised Recreational
       Water Criteria and Standards for Drinking Water Sources and Shellfish Harvesting
       Waters

Workgroup  members considered that any change  in  recreational water  criteria that led  to
improved public health protection would not negatively impact on the  risks  from drinking water
or shellfish consumption.  However, some workgroup  members  did express concern about any
change that would  encourage further recreation in waters intended to be used for drinking water
production or for shellfish harvesting. When people bathe they invariably contaminate the water
to some extent with potential pathogens.   Such pathogens may then be  concentrated within
shellfish or contaminate drinking  water supplies and pose a health risk to others.

5.2.7   Areas of Discord

Although workgroup members accepted  that the phrase "acceptable risk"  was widely used, they
realized that there  were difficulties in its general  acceptance.  However, no alternative to the
phrase was  thought  to be "acceptable" to all workgroup  members.   Although  the  phrase
"tolerable risk" is now being used more frequently internationally, it was still not tolerated by all
members of the workgroup.

5.3    Research Needs

    1.  Risk perception  studies  to inform the risk communication  strategy for the criteria
       rollout and focus groups to evaluate the risk communication strategy
          a.  Assess public understanding of relative versus absolute risk.
          b.  Key research  questions  include  the following: (1)   What  does  the  public
              understand currently? (2)  What does the public think of when one uses the term
              "acceptable risk"? (3) How does the public interpret existing criteria and  beach
              closures/advisories? (4) How does/should EPA communicate this risk? and (5)
              What level of risk would the public accept?

    2.  Define the data  and  conditions  where a directed  monitoring program  would be
       necessary to protect against certain non-enteric (non-GI) illness.
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          a.  Such research would probably require pathogen-specific studies, and a possible
              role for QMRA.

    3.  EPA should  investigate expanding the role of QMRA, particularly for investigating
       rare but potentially severe (and life-threatening) illnesses that may be associated with
       recreational water exposure such as EHEC (e.g., E. coli O157:H7).
          a.  Define data needed for the QMRA modeling for special/outbreak cases and also
              for background/regular situations.
          b.  Engage EPA experts in QMRA in recreational water research.
          c.  Explore  approaches to integrate QMRA (and/or  dynamic modeling) to  better
              understand recreational risk, especially situations with rare, but potentially severe
              outcomes.

    4.  Conduct methodologic comparisons in tropical and subtropical recreational waters and
       if appropriate, conduct epidemiological studies.
       Methodological and ecological studies need to be conducted in tropical and subtropical
       recreational waters because of issues such as regrowth, significant spatial  and temporal
       variability of both indicator organisms and pathogens in the water and soils, substantially
       different ecosystems  and climatic conditions  (including  heavy rains), and possibly a
       greater range of exotic pathogens. These studies would determine the impact of these
       environmental factors on  the use of proposed indicators  organisms to  be used for
       monitoring and regulatory purposes.  Depending  on  the results  of  these studies,
       assessment of the need for epidemiologic studies specifically in tropical and subtropical
       recreational waters should be performed.  This information will be essential to determine
       whether the same recreational water criteria as used elsewhere in the United States are
       also  appropriate in these waters.  Information on risks in such waters will help ensure
       appropriate risk communication to healthcare providers, public and environmental health
       managers, and residents of and visitors to tropical  and subtropical areas concerning the
       risks of tropical and subtropical recreational waters.

    5.  Ensure that future epidemiological studies obtain data on and existing studies are
       reviewed for risk to children.
       Children appear to be  at  increased risk  for acquiring GI illness and possibly other
       illnesses from exposure to recreational waters; therefore, workgroup members felt future
       recreational water criteria  should be based on the health risk to children.  If existing
       standards are deemed not to provide  sufficient protection  to children then additional
       information will be needed to establish new or revised criteria that are thought to provide
       sufficient protection.  Such information will also be essential to provide risk information
       to parents and others responsible for children.

    6.  Review prior  data to evaluate whether additional epidemiological studies are needed to
       determine the risk of severe disease to pregnant women and their fetuses, to the elderly,
       and to immunosuppressed individuals.
       There  is  evidence   that  pregnant  women  (and their  fetuses),  the  elderly,  and
       immunosuppressed people may suffer more serious disease and/or more serious health
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       consequences from recreational bathing waters.  If these data show that there may be
       increased  risks, then the  incorporation  of these subpopulations  as  specific target
       populations in future epidemiological studies should be considered.  Information on risks
       in such waters will help ensure appropriate risk communication to healthcare providers,
       public, and environmental health managers, and these potentially increased risk groups
       from recreational waters.

    7.  Determine how risks in tourists and visitors differ from those in residents.
       There is some evidence that risk may be greater for tourists and visitors than for residents
       local to a recreational water; thus, current estimates may underestimate the actual risk and
       so give inappropriately lax criteria (Payment and Hunter, 2001).  Consideration should be
       given to the design and implementation of future epidemiological studies to address risk
       in tourists and visitors. It may  also be possible to review data from previous studies to
       determine if there are increased risks to tourists.  Information on  risks in such waters will
       help  ensure  appropriate  risk  communication   to  healthcare  providers,  public,  and
       environmental health managers, and tourists with exposure to recreational waters.

    8.  Ecology of swimming-related waterborne pathogens, including studies on  the role of
       bather shedding on transmission of illness and microbial water  quality indicators
       Further  studies  are needed  to understand the  role  of bather shedding  in disease
       transmission and microbial water quality indicator levels.  How efficiently are pathogens
       transmitted through swimming or bathing?  This could be an experimental  study, partly,
       augmented by epidemiology  (serology,  or microbial source tracking in a small study
       population).

    9.  How many illnesses are prevented by beach closures?
       Studies of the number of illnesses prevented by beach closures would be primarily  a
       modeling/statistical exercise.   First, the procedures/modeling  assumptions should be
       agreed upon.  It could be done relatively easily in a QMRA-type of study.

Table 6 provides a summary of how each workgroup member ranked the above research needs in
relation to overall importance (1 to 5), relevance to EPA, and estimated time needed to  complete
the project.
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Table 6. Research Needs and Rankings from Five "Acceptable Risk" Workgroup Members.
Description
Conduct risk perception studies to inform
the risk communication strategy for the
criteria rollout and focus groups to
evaluate the risk communication strategy
(#1)
Assess public understanding of relative
versus absolute risk (#1)
Define the data and conditions where a
directed monitoring program would be
necessary to protect against certain non-
enteric (non-GI) illness (#2)
Define data needed for the QMRA
modeling for special/outbreak cases also
for the background/regular situation (#3)
Engage QMRA in recreational water
research (#3)
Explore approaches to integrate QMRA
(and/or dynamic modeling) to better
understand recreational risk, especially
situations with rare, severe outcomes (#3)
Conduct future epidemiological studies in
tropical and subtropical bathing waters
(#4)
Ensure that future epidemiological
studies obtain data on and existing
studies are reviewed for risk to children
(#5)
Review prior epidemiological studies to
determine the risk of severe disease to
pregnant women and their fetuses (#6)
Review prior epidemiological studies to
determine the risk of severe disease to the
elderly (#6)
Review evidence about whether or not
immunosuppressed individuals are at
increased risk from recreational bathing
waters (#6)
Determine how risks in tourists and
visitors differ from those in residents (# 7)
Conduct studies on the role of bather
shedding on transmission of illness and
microbial water quality indicators (#8)
Determine the ecology of swimming-
related waterborne pathogens (#8)
Determine how many illnesses are
prevented by beach closures? (#9)
Importance
5
1
3
3
2
4
4
5
2
1
4
4
5
3
4
5
2
o
J
4
o
3
2
4
4
2
2
o
J
5
5
4
4
5
1
2
3
3
4
2
5
1
1
1
2
5
3
4
5
3
o
J
o
J
o
J
3
5
5
3
3
4
4
4
5
5
5
3
3
5
5
4
5
5
5
5
5
4
5
3
3
Relevance to EPA
5
1
o
J
o
J
2
4
4
5
2
1
4
4
5
3
4
5
1
3
4
3
2
4
4
2
2
3
5
5
4
4
5
1
2
o
J
4
4
2
5
2
2
2
2
5
3
4
5
3
3
3
3
3
5
5
5
5
5
4
5
5
5
5
3
o
J
5
5
4
5
5
4
4
o
J
5
5
5
5
Near- and/or Long-term
Nand
L
Nand
L
Nand
L
Nand
L
Nand
L
Nand
L
N
N
L
L
L
N
N
L
Nand
L
N
N
N
L
N
L
N
N
L
L
N
N
N
L
N
N
N
L
N
N
N
N
N
L
L
N
L
N
L
N
N
N
N
N
N
N
L
L
L
L
N
N
L
L
N
N
L
L
N
N
N
L
N
L
L
N
L
N
L
N
Scoring for importance: score 1 not at all important to 5 highly important
Relevance to EPA: score 1 not at all relevant to 5 highly relevant
For time: N (within next 2 to 3 years); L (within next 10 years)
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References

Chorus, I; Bartram, J (eds). 1999. Toxic Cyanobacteria in Water: A Guide to their Public Health
Consequences, Monitoring and Management. London: E & FN Spon and Geneva, Switzerland:
World Health Organization (WHO).
Available at: http://www.who.int/water_sanitation_health/resourcesquality/toxcyanobacteria.pdf.

Fleisher, JM; Kay, D; Salmon, RL; Jones, F; Wyer, MD; Godfree, AF.  1996. Marine waters
contaminated with domestic sewage: Nonenteric illnesses associated with bather exposure in the
United Kingdom. American Journal of Public Health 86:  1228-1234.

Fleming, LE; Rivero, C; Burns, J; Williams, C; Bean, J; Shea, K; Stinn, J. 2002. Blue green algal
(cyanobacterial) toxins, surface drinking water, and liver cancer in Florida. Harmful Algae 1(2):
157-168.

Payment, PR; Hunter, PR.  2001. Endemic  and  epidemic infectious intestinal disease and its
relation to drinking water. Pp. 61-88 in: Fewtrell, L; Bartram, J (eds) Water Quality Guidelines,
Standards and Health. Risk Assessment and Management for Water-related Infectious Disease.
London: IWA Publishing.

US EPA (U.S. Environmental  Protection Agency).  1986. Ambient Water Quality Criteria for
Bacteria-1986. EPA440/5-84-002. Washington, DC: US EPA.

WHO. 2003. Guidelines for Safe Recreational  Water Environments.   Volume 1 Coastal and
Fresh Waters. Geneva, Switzerland: WHO.
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                              CHAPTER 6
  MODELING APPLICATIONS FOR CRITERIA AND IMPLEMENTATION
                Alexandria Boehm, Chair, Stanford University, California
                Donna Francy, U.S. Geological Survey
                Mark Pfister, Lake County Health Department, Illinois
                John Wathen, USEPA
                Richard Zepp, USEPA
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6.1    Introduction

The Modeling workgroup was charged with determining how models might be incorporated into
future recreational water criteria development and implementation.  Workgroup members did not
explicitly  consider total maximum daily loads (TMDLs)  in the discussion because models are
already being used in TMDLs for pathogens throughout the United States.  The discussion
focused on what was generally felt to be the most important novel applications of models in new
or revised recreational ambient water quality criteria.

In the  context of recreational water quality criteria, a perfect model would allow prediction of
fecal indicators, pathogens,  or risk as a function  of source presence and strength relative to
physical, chemical, biological, and human variables.

There  is limited understanding regarding the sources of microorganisms  and their fate and
transport in the aquatic environment, so the use of deterministic, process-based models (see
Appendix G) in criteria development and implementation is not practical for most U.S. water
quality managers within the next five years (2012).  Rather, simple heuristic, statistical models
that do not necessarily require an understanding of processes and mechanisms are more
realistic for criteria development and implementation within the next 5 years. This is not to
say that substantial research should not go into refining understanding of  sources, fate, and
transport of pathogens and pathogen indicators and their spatial and temporal variability in water
and sediments.  Thus, workgroup members suggested that a substantial  research effort go into
understanding these processes in watersheds and near-shore waters as this will have profound
impacts of development of future ("next generation") recreational water  quality criteria (see
Section 6.5).

Workgroup members saw two roles  for models in the development and implementation of near-
term (five years) new or revised criteria:  (1) recreational water quality notification models and
(2) models to support sanitary investigations  (hereafter  referred to as  "sanitary investigation
models" for simplicity). Recreational water quality notification models are already in use in the
Great Lakes and have proven to be effective and popular with the public  (Francy and Lis, 2007;
Olyphant, 2004; Whitman, 2007).  There are a handful of sanitary investigation tools and models
that are   accessible  to  recreational  water  managers  throughout  the  country   (e.g.,
DigitalWatershed, the  BASINS3  system).   The main focus of this  chapter is  water  quality
notification models because these are easily accessible to a wide  range of recreational water
managers in the near-term.  However,  because  workgroup  members viewed  the  sanitary
investigation model as an area of near-term research activities and investigation, with possible
applications in the near-term development of new or revised criteria and/or implementation,
discussion of sanitary investigation models was included as well.

6.1.1   Water Quality Notification

Numerous research studies in the peer reviewed literature show that a single sample standard
implemented in conjunction with assays that require incubation longer than a few hours results in
less accurate management decisions (Francy and Darner, 2006; Hou et  al., 2006; Kim and Grant
2004).   That is, by the time results from analysis of a water sample are available  and a water
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quality notification is issued, the microbial water quality may have changed. This is due to the
inherent variability in indicator bacteria levels over timescales shorter than a day (see Figures 4a
and 4b), as measured by culture-based assay, both with selective membrane-filtration media and
                350-
              o
              o
                300-
                250-
              §,200-

              o 150-1
              g 100-
              -I—•
              "5  50-
                    12:00
                   10/22/05
18:00
 00:00
10/23/05
06:00
            Figure  4a.  Enterococci (MPN/100 mL) Sampled Every 10
            Minutes at a Beach in California. (The reference background
            denotes the range of single sample exceedance.)  SOURCE:  A.B.
            Boehm, unpublished data (ENTEROLERT assay).
                     48-Hour Sampling  - Water
                            HEAVY LIGHT
                             RAIN RAIN
                                            RAIN    RAIN
            Figure 4b. Subtropical  Marine Beach  (Miami, Florida):   48
            hours Sampling. SOURCE: Amir Abdelzaher, Samir Elmir, Lora
            Fleming, Kelly Goodwin, Helena Solo-Gabriele, John Wang, Mary
            Wright, University of Miami, personal communication, 2007.
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defined substrate  technologies  such as Quanti-Tray  (IDEXX,  Westbrook, Maine).   Note,
variability  in  indicator levels  as  measured  by nucleic acid-based assays (like  quantitative
polymerase chain  reaction  [qPCR]) has not been well characterized  in the  peer reviewed
literature.   The variability in Figures 4a and 4b is not unusual in environmental  waters because
"patchiness" is an  inherently natural phenomena.  A water quality notification model can be
used to augment monitoring data and provide more timely and accurate recreational water
quality notification to better protect the public from exposure to waters not in  compliance
with water quality criteria or standards.

Summary  of near-term research needs (i.e., the next 2 to 3 years) specific to water  quality
notification include (see Section 6.5 for further information) the following:

    1.  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 due to
       time-lag notification errors as discussed above.  Simple, heuristic or  statistical water
       quality notification models are one way to improve water quality notification  accuracy.
    2.  Immediate research needs include the following:
           a.  Testing whether models can be used to predict health outcomes during upcoming
              epidemiological  studies  in California and in Alabama and Rhode Island and
              retrospectively for the Great  Lake epidemiology study in the Great Lakes (Wade
              et al., 2006) (that is, risk = f[temperature, tides, waves, etc.]);
           b.  Developing and testing simple notification models on different recreational water
              types with a wide range of sources and geographical locals;
           c.  Exploring the feasibility of developing  regional models that apply to more than
              one recreational water;
           d.  Training recreational water managers; and
           e.  Creating a user-friendly portable package for developing local models.

6.1.2   Sanitary Investigation

Quantitatively determining the potential for  a waterbody to be impaired with human pathogens is
essential if the European  Union (EU; EP/CEU, 2006) or World Health Organization  (WHO,
2003) approach to criteria development is  undertaken (i.e.,  sanitary investigation is integrated
into the criteria).  This potential could be determined using a "toolbox approach" in conjunction
with water quality notification  models  or sanitary investigation  models.  In the first case,  the
water quality notification  model results can be used to learn about the factors that influence
water quality in recreation waters;  for  example,  high rainfall and wave action from  a given
direction and of a given height might lead to greatest impairment. The occurrence of these
environmental conditions  can be used to trigger sampling  for "toolbox" approaches  such as
analyses for human-specific or bird-specific markers and human pathogens to "rule in"  or "rule
out" high probability  of human pathogen presence.  In the second case  (sanitary investigation
models), simple, quantitative sanitary investigation models  that relate watershed  attributes to
probability of human pathogen impairment may be developed.
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Summary  near-term research  needs  (i.e., the next  2 to 3  years)  specific to sanitary
investigation models include (see Section 6.5 for further information) the following:

    1.  Simple, heuristic  or statistical models that correlate watershed  activities (presence of
       wastewater/sewage  treatment plant effluents, agricultural activities,  and domesticated
       animals) and attributes (slope, soil type, climate, soil moisture) can be used to determine
       the susceptibility of a waterbody to pathogen impairment.
    2.  Research  should  be  conducted  to  better understand how watershed  activities  and
       attributes relate to pathogen presence in  streams  and  receiving waters and include the
       following:
          a.  factors that modulate septic tank impact on waterbodies;
          b.  factors that modulate contributions of animal wastes to  pathogen and pathogen
              loads to waterbodies;
          c.  sources in urban landscapes  (e.g., broken/leaky sewer  pipes, combined sewer
              overflows [CSOs], runoff); and
          d.  effect of meterological factors (e.g., rainfall, evapotranspiration, etc.)  on non-
              point sources.

6.2    How Models are Currently Being Used

6.2.1   Sanitary Investigation Models

Sanitary  investigation models  that  explore the relationship between  land use,  watershed
attributes, and water quality are already in place  and have been used in TMDL implementation
(criteria  implementation);  however,  they  have not  been  specifically  applied to  criteria
development.  Creating a TMDL-like model for a waterbody prior to impairment may be viewed
as proactive rather  than  reactive.   Such models  in  use include  deterministic models  like
Hydrological  Simulation  Program-Fortran  (HSPF) and Storm  Water Management Model
(SWMM) for  watershed  loading,  and CE-QUAL models for pathogen fate  and transport  (US
EPA, 2002).   Feedback from some environmental engineers  and consultants who apply these
models to  pathogen  and  fecal  indicator  transport suggests they provide  highly uncertain
predictions  for  pathogen  and indicator concentrations  and fluxes  (Ali  Boehm, Stanford
University, personal communication, 2007).

If sanitary  investigation  models are to be used for criteria development (i.e., prioritizing or
discounting procedure for various type of sources), then models that are quantitative yet simple
must  be  available to managers who do  not have the  resources to run full-scale simulations.
These quantitative simple models need to relate land use activities and patterns to the likelihood
of human pathogen presence. The ability to rule in or rule out the presence of human pathogen
sources in a watershed would be useful to recreational water managers—especially if the EU or
WHO approach to criteria development is undertaken.   The relationship  between land use
patterns and microbial water quality has been investigated quantitatively along the California
coast (Handler et  al., 2006), lakes of South Carolina  (Siewicki et al.,  2007), North Carolina
(Mallin et al., 2000), and Georgia (Fong et al.,  2005;  Vereen et al., 2007).  In Australia, the
relationship  between land use and watershed attributes and pathogens and pathogen indicators
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has been applied to numerous catchments using what is termed "pathogen catchment budgets
(PCBs)" (Ferguson and Croke, 2005; Ferguson et al., 2007).  A sanitary investigation model, for
example, might indicate that a completely undeveloped watershed with no agriculture has very
low probability of producing runoff containing human pathogens and could potentially place a
water body in a "low concern" tier in criteria similar to the EU or WHO approaches (see Tables
1 and 2, Chapter 1).   Such models are being developed  and used in the  U.K. for criteria
implementation   and  development (David   Kay,  University of  Wales,   U.K.,  personal
communication, 2007; Kay et al., 2005, 2007).

6.2.2   Water Quality Notification Models

Water quality notification models that are most commonly used are simple heuristic models that
relate rainfall to water quality.  More complex models currently in use for informing advisory
and closure  decisions are exclusively statistical  models that are used in  conjunction  with
historical water quality data.  The models draw on a body of past recreational water monitoring
water quality data and temporally-associated physical parameters. The models are developed by
assessing and exploring  data for parameters that correlate most strongly with variations in water
quality detected over the course of monitoring for pathogen indicators.  Promising variables are
selected, regression models  are tested, and the models  are  refined on the basis of the results
obtained using single variables and/or sets of variables.

Another type of "model" for water quality notification is the Heal  the Bay Beach Report Card
grading system (http://www.healthebay.org/brc/statemap.asp), which provides grades for water
quality that are updated daily and formulated using more than one water quality measurement.
Given the major uncertainty and variability in measured microbial water quality (e.g., Figures 4a
and 4b), this is highly preferable compared to using a single sample to drive public water quality
notifications.

One workshop participant (not from the Modeling workgroup) suggested that neural network
models  be used  to model water quality  for notification.  Neural networks relate independent
variables to  a dependent variable non-linearly and have been used to model fecal coliforms in
some  waterbodies (Kumar and Jain, 2006; Neelakantan et al., 2002).  However, the Modeling
workgroup members agreed that neural network models would not be accessible to the majority
of U.S. recreational water quality managers and public health officials in the near-term (5 years).
In addition, neural network models have not been used previously for water quality notification,
so  they are  probably not going  to be useful in  the near-term.   They are,  however, worth
examining in the future.

Simple  statistical models have been developed for Great Lakes and West Coast recreational
waters  that  link fecal  indicator  concentration  with  meteorological  and water quality
data/information,  and include the following:

    •   water quality  and dynamic hydrologic  variables (e.g., water temperature, turbidity,
       currents, wave height, tide level or range, lake height);
    •   optical property data (e.g., UV and visible irradiance, light scattering, cloud cover);
    •   meteorological parameters (air temperature, wind speed/direction, rainfall, pressure); and
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    •   other factors  (e.g., bird  counts  near a recreational water, number of swimmers in the
       water, video  counts of swimmers  and wildlife, flow/discharge from a storm drain or
       nearby creek).

These models have been used very successfully in three states in the Great Lakes to predict the
likelihood of exceedance of the current (US EPA, 1986) indicator bacteria criteria for public
water quality notification.  The  models have been shown to be effective in predicting indicator
concentrations  for compliance  and for making timely  public health decisions  relative to
recreational water advisories and beach closures.

The short-term predictions derived from these statistical  models  have been  referred  to as
"nowcasting."  Nowcasting  has  been described  in the peer reviewed literature (Boehm et al.,
2007; Francy et al., 2002, 2003; Hou et al., 2006; Nevers et al., 2005).  The variables that are
used to correlate with indicator concentrations vary depending on  the type of setting of the
recreational water. Among the descriptive variables assessed to date, turbidity, rainfall, tides,
and wave height have been found to be among the most highly-correlated.  The success of these
models has been  evaluated by their effectiveness in  predicting  days when current EPA limits
have been exceeded and comparing predictions with bacteria concentrations from monitoring on
a given day.

Statistical tools  such as  Swimming  Advisory  Forecast  Estimate (SAFE)  and  SwimCast
(http://www.earth911.org/waterquality/)  for Lake Michigan and nowcasting models for Lake
Erie are  being used  to warn the public about potentially unhealthy conditions  in recreational
waters.  Project SAFE is a statistical model used for the five recreational waters in Lake  and
Porter Counties that  extend to the west of the Burns  Ditch outfall (Ogden Dunes, West, Wells
Street,  Lake Street,  and  Marquette  Beaches).   These beaches  are directly affected  by
contaminants in the Burns Ditch outfall, particularly during prevailing north wind  conditions.
Project SAFE models provide a far better real-time estimate of E. coli counts than advisories
based on single sample monitoring, and  are generated for the five beaches  simultaneously.
Similar applications  are being developed for other Great Lakes recreational waters.  Another
instance  of statistical model use is the Ohio Nowcast system.  The U.S. Geological Survey
(USGS) and Cuyahoga County Board of Health are implementing a pilot Nowcast project to test
the use of a statistical model  at Huntington Beach, Bay Village, Ohio (Francy and  Lis, 2007).
Nowcast was used as a tool for recreational water closure  decisions for the first time in Ohio in
2006. If the testing goes well, the Nowcast model will be used in subsequent years at other Lake
Erie recreational waters.

In all cases where models  are being used in the Great Lakes,  the modeling is being used to
augment  microbial water quality monitoring that is being continued as required by the National
Beach  Guidance  and Required Performance Criteria for Grants (US  EPA, 2002).  In Lake
County Illinois  (SwimCast) all recreational waters are monitored each day in the morning and 5
days per  week in the afternoon  at locations used for obtaining data for  statistical modeling.  In
Indiana (SAFE model)  recreational waters are monitored once a week.   In  Ohio  (Nowcast)
monitoring occurs 4  days per week at most Lake Erie recreational  waters; and at Huntington
Beach, monitoring was increased to 7 days per week during 2006 to provide a large  data set to
test the accuracy of the Nowcast system.
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Hou et al. (2006) and Frick and Ge (submitted) have taken other important steps in developing
useful statistical tools for use in recreational water quality notifications.  Currently used models
are based on long time-series records because  models developed  from large data sets  are
generally considered better than models developed from smaller data  sets.  However, large data
sets are developed over time, so this approach is "static."  Because conditions at recreational
waters are highly dynamic and change from year-to-year and as the season progresses, these
authors'  models use a dynamic  approach in which the descriptive  variables are updated
periodically.

6.2.1   Communication of Modeled  Information to the Public and Recreational Water
       Managers

Information  on  modeled projections of water quality has been  communicated to the public
through the  use of a range of  communication media  and in  a variety of information formats.
Internet postings, radio spots, and local signs have all been employed in communicating the
output of regression model-based advisories. Model outputs intrinsically include an estimate of
error.  This  is expressed in the Nowcast program in a manner similar to the familiar weather
forecast probability of precipitation (POP).  That is, the likelihood of an exceedance of water
quality standards for a given day is  expressed as a  percentage.  In SwimCast, the  modeled
estimate of fecal indicator concentrations is provided with the average prediction and the upper
and lower bounds of the 99th percent confidence limit of the projected figure.  Because the value
of that number  to the general  public  is limited,  a risk explanation  is  reported based on this
statistical prediction  in terms of a text  description (e.g., low risk if entire confidence interval is
below the single sample maximum criteria).

Information  on beach water quality can be provided to the public through a tiered approach. The
first tier involves communicating a red or green light; that is, simply informing the public on
whether or not the recreational water  is currently posted with  a water quality advisory.  The
second tier is to provide additional information for those who desire to be more informed and
could include posting the measured water quality, environmental water quality data,  and the
resultant numerical prediction on a website.  The third tier is to provide detailed information on
the Nowcast system and explain how statistical models are developed  and tested, which can also
be provided  on a website or summarized in fact sheets distributed to the public at the recreational
water.  A tiered system allows the recreational water user the ability to choose their desired level
of information.

Effective communication to the recreational water manager  and state and local public health
agency representatives is essential for acceptance of a Nowcast or similar system.  Presenting the
science behind statistical modeling in a simple and concise manner at periodic workshops and
meetings is the first  step toward gaining acceptance.   Because the Nowcast  system is different
from conventional water quality notification systems already in place (i.e., using the previous
day's measured bacterial  indicator concentration),  local  officials  may be apprehensive  in
accepting the new technological approach.  Thus, demonstrating to local agencies that  the
Nowcast system provides  a more  accurate assessment  of water quality conditions may be
required before acceptance and implementation is achieved.
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6.3    Advantages and Disadvantages of Modeling

The main advantage of modeling for water quality notification  is that modeling can provide
accurate and timely notification of water quality, whereas day-to-day monitoring cannot.  Such
modeling may be as simple as  a heuristic model  or a letter grade for recreational water.  More
complex models, such as those already in  place in the Great Lakes, use multiple regression
modeling or similar tools.

An advantage of using a simple sanitary investigation model that relates land use activities and
patterns to microbial water quality is that a manager may be able to rule in or rule out the
presence of human pathogen sources  in a watershed to relax criteria, as is proposed in the EU
(EP/CEU, 2006) and WHO (2003) approaches to criteria development.

6.3.1   Advantages of Modeling

    •   Statistical/regression fecal indicator estimation models are relatively easy to create for an
       individual with knowledge of statistics and may in some cases only require one variable
       to  adequately describe/predict the pathogen indicator.  Several government or  private
       entities  currently maintain hydro-meteorological equipment and sensors (e.g.,  USGS,
       National Oceanic and Atmospheric Administration [NOAA]) with readily accessible real-
       time data via the Internet, which could be used at no cost to the recreational water quality
       manager if deemed appropriate for the specific recreational water.  Collected descriptive
       variables can either be  continuous or categorical.  Once developed and put into place,
       statistical models are also  easy to use with minimal training required for the recreational
       water managers and operators.
    •   Predictions from a sanitary investigation model may allow managers to rule in or rule out
       human pathogen sources in their watershed and hence relax water quality criteria using
       an EU or WHO criteria approach.  Land use and watershed attributes may be  readily
       available  for  incorporation  into  such  a  model  (e.g.,   Digital   Watershed,  see
       http://www.iwr.msu.edu/dw/).
    •   Water  quality notification predictions may  be made "near" real-time if required data
       elements (input  variables) exist.  This  alleviates the delay  currently  experienced  by
       culturable methods (18 to 24 hours for E. coli or at least 24 hours for enterococci). Even
       with the advent of rapid qPCR (molecular-based) methods, there will continue to be time
       associated with  collection, sample preparation, analysis, and results  evaluation.   For
       example, sample preparation adds an estimated minimum of 2 hours in addition to the
       analysis  time.  In  addition, only the most intensively used waterbodies will likely be
       monitored with a frequency that will make the best use of the timely results from the use
       of these methods.
    •   Collection and analysis  delays  for both culture- and non culture-based methods currently
       have and potentially will continue to result in false negative (Type II) advisory/closure
       errors (e.g., contaminated  recreational waters remain open).   This is due to the inherent
       variability of fecal  bacteria densities—even over time scales as short as every 10 minutes
       (see Figures 4a and 4b).  Statistical models created for various recreational waters in the
       Great Lakes have been successfully used to correctly advise/notify the recreational water
       user of current fecal indicator conditions.  Proper public notification should result in


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       improved public health outcomes and is the major benefit of statistical modeling. It has
       been well received (instills confidence) by the public and recreational water managers
       and operators at currently used recreational water locations.
    •   For recreational waters that have daily (or multiple  day per week) monitoring of a fecal
       indicator and other hydro-meteorological data, costs for creating a statistical  model will
       be low relative to other monitoring/advisory costs.  For many recreational waters, initial
       model  creation will require  additional water  quality  monitoring for fecal indicators
       because it is imperative that the data set on which the model is based include a full range
       of fecal indicator concentrations for the specific location.  However, once the statistical
       model  is created and is  validated, the need for daily  or  weekly monitoring could be
       reduced, potentially reducing monitoring costs.
    •   Once the statistical model has been created, both the data-element collection and actual
       prediction can be automated using current technologies.  Although automation  initially
       increases costs (i.e., equipment and programming), personnel  costs should be  reduced
       over time.
    •   Many  recreational  waters are  monitored  infrequently due to  economic  reasons or
       logistical issues (e.g.,  difficulty of sampling on weekends).  Statistical  modeling, if
       relatively automated, will improve water quality notification activities at these locations,
       often during highest use days.
    •   When  associated  variables  become  known  during model  development,  a  deeper
       understanding and knowledge of the potential reasons driving  increased fecal indicator
       concentration should assist the recreational water operator (and other interested  parties)
       with future assessments and sanitary investigation work.  Simple linear relationships can
       help to identify potential sources of fecal indicator bacteria (i.e., waterfowl counts versus
       E. coli measurements)  and can be used to help design monitoring and microbial source
       tracking studies.
    •   Currently used  statistical models are based on recreational water quality criteria and thus
       meet Beaches Environmental Assessment and Coastal Health (BEACH) Act of 2000 and
       recommended Clean Water Act (CWA) §304(a) single sample maximum allowable fecal
       indicator density  requirements.   Because previous  studies have  demonstrated  that the
       currently-used  bacterial  indicators are statistically associated with acute  GI  illness,
       predictions based on these pathogen indicators should be protective of public health.
    •   Statistical models  could  possibly be used  to forecast poor conditions at recreational
       waters using forecasted descriptive variables available from NOAA.
    •   The  statistical approach is flexible and could be applied to prediction of other criteria
       besides  the current culturable E. coli- and enterococci-based criteria.  However, new data
       would be required  to calibrate the models if the criteria  changes and this  could  be a
       disadvantage  (see more below).

6.3.2   Disadvantages of Modeling

    •   Because water quality notification models are based on  real-time  data,  prediction
       accuracy  may  be diminished by poorly  collected  or inappropriately  maintained
       equipment.  Quality assurance and quality  control  procedures  must be in place for all
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       required  input  data  elements.   Recreational water  managers  and operators  (or  other
       individuals) must be diligent  in ensuring that  proper collection  and data management
       techniques are used.
    •   Because  current  water  quality  notification models utilize statistical  techniques, a
       relatively large (n = 75) and rigorous data set  is required to develop the model.  Both
       dependent and assumed  descriptive variables should be  collected  at  least  3  to 4
       days/week during the recreational water season (if possible). Additionally, the  data set
       should contain a variety of sampling events to capture temporal variability (morning and
       afternoon) and under both wet and dry weather conditions.  It is also necessary to attempt
       to sample and  collect the full  range  of fecal indicator  concentrations  for a  specific
       recreational water to help ensure accurate future predictions.
    •   Politicians, government officials, recreational  water operators and  managers,  and  the
       public may be apprehensive to accept the concept or the need for a modeling-based water
       quality notification  system.   Initial support may be difficult to obtain and  a  local
       "champion" would be beneficial to advance the  concept. The workgroup members noted
       that once a model is created and accurate predictions  are demonstrated, this apprehension
       would lessen  substantially over time.
    •   Statistical water quality notification models are based on  previously collected data and
       historical  associations.  Unanticipated  events such as sewage spills, large increases in
       wildlife populations, changes in shoreline from extreme weather events, or new non-point
       sources of fecal  contamination may reduce the  predictive ability  of the model.   If
       numerous under- or over-predictions occur, additional data collection activities would be
       warranted to determine whether the model would need to be modified.
    •   Statistical water quality notification  models appear to be most useful at recreational water
       locations  that have  occasional but  infrequent  exceedances  of current bacterial water
       quality criteria.   Recreational waters with  consistently  low  or high fecal indicator
       concentrations may be very difficult to model.  Additionally, the need for  modeling will
       be harder to justify as currently accepted monitoring designs may be a preferable and
       cheaper method.
    •   Simple statistical  models, whether for recreational water quality notification or  sanitary
       investigations, are generally  not sufficient for use as  deterministic models  (e.g., bacterial
       fate and transport) or to provide load estimates for use in developing TMDLs.
    •   Current statistical water quality notification models  are based  on recreational water
       criteria and thus  meet  BEACH Act and recommended CWA §304(a)  single sample
       maximum allowable fecal indicator density requirements.   However,  if ambient water
       quality criteria for bacteria change, all currently used statistical models will need  to be
       modified to reflect and predict the new criteria.  This will result in  new costs in  the
       redevelopment  and  modification  of an  existing model to incorporate  the  changed
       relationships  of predictive variables to indicator concentrations.   In addition, because
       fecal indicators are used to predict health risk, the model is only as good as the indicator
       used.
    •   There is  some  confusion as to whether a model output should be measured against a
       single sample standard and/or a 30-day geometric mean standard.  Input from workshop
       participants revealed that these criteria  are used  differently around the country with
       monitoring data.  Output from water quality notification models should be used with the


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       single sample standard and not the 30-day geometric mean standard because it is not clear
       that model outputs should be averaged for comparison with the 30-day geometric mean
       standard.  Guidance  needs to be  provided on this issue if new or revised  recreational
       water quality criteria will support the use of models.
    •   Because water quality is inherently variable, even over a 10-minute scale (see Figures 4a
       and 4b), how to collect data to  develop and validate models needs to be carefully
       considered. In the Great Lakes, composite sampling is conducted. Guidance for any new
       or revised criteria that recommend models would need to address this.
    •   There was some concern from the Implementation Realities workgroup that recreational
       water advisories or closures instigated by model  output would count against them for
       CWA §303(d) listings or other CWA applications.  Guidance  for any new or  revised
       criteria that recommend models would need to address this concern.
    •   Models are site-specific  and must be developed for various recreational sites, the same
       way water quality monitoring must be conducted at specific sites.
    •   Sanitary  investigation models have  not been used before  for water quality  criteria
       development.

6.4    Model Development and Evaluation

6.4.1   Initiating Model Development for Water Quality Notification

Prior to initiating statistical model development at any recreational water site, a review of all past
monitoring and watershed data  should be completed.  In some cases, enough  data may  exist to
analyze associations between the environmental variables and  indicator densities.  For example,
some  states  and local agencies collect data  on air and water temperature, rainfall, amount of
algae  wrack, and/or tide level during compliance water monitoring.  This type of ancillary data
can be used to develop preliminary models and determine if any relationships between indicators
and readily available environmental variables exist.  This may guide additional monitoring needs
and variables to be assessed.  As always  should be the case, strict quality assurance and quality
control practices are to  be followed to ensure that a high quality data set has been or  will be
collected.  Additionally, a good understanding of the potential sources and extent of fecal
contamination should be determined to aid in choosing sample locations and frequencies. This
type of information can be obtained from recently conducted sanitary investigations,  historical
observations from local water resource managers, and/or visits to the recreational water site.

6.4.2   Model Development for Water Quality Notification

Statistical models have relatively  easy to obtain  data needs.  Data collection should  include
observations that cover the range of hydrometerological conditions that are expected to impact
the recreational water.  Sampling should  be  conducted, at the very least, by collecting  at least
two recreational seasons of data. A minimum of one recreational season will be necessary for
model creation,  while the second  is used to gather additional data  and for  model evaluation.
Water should be collected four or five times each week and the data set should contain a variety
of sampling events to capture temporal variability (morning and afternoon) under both wet and
dry weather conditions.   It is also necessary to attempt to sample and collect the full range of
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fecal  indicator  concentrations for a specific recreational  water to ensure  accurate  future
predictions.   If current monitoring  is  conducted  on  a  weekly  or monthly basis,  serious
consideration should be given to increasing data collection requirements as it will take a much
longer time period (i.e., 5 years) to develop the model.  Generally, a relatively large (n = 75) and
rigorous data set is  required  to  develop a water  quality notification  model.   Recreational
locations that have consistent good or bad water quality are not good candidates for statistical
models.  Rather, sites with mixed water quality conditions are the best candidates for statistical
models.  A representative sample  of the waterbody (multiple point grab samples or composite
samples for larger recreational areas) should be analyzed for concentrations of fecal indicator
bacteria, such as E. coli and enterococci, determined by use of an EPA-recommended method.

The descriptive  variables for each recreational waterbody will differ from site-to-site.  More
precise  and frequent  measurements  may lead  to better statistical  models but  also lead  to
increased costs.  However, increased  equipment use does lead to automated processes, greater
reliability of measurements, and reductions in personnel time.

Water quality notification models use a variety of descriptive variables and all are based on
statistical correlations between  descriptive variables and  indicator organisms. Wave height has
been shown to have a positive association with fecal indicator bacteria at  some beaches and thus
is often included as an independent variable in water quality notification models.  Wave height
can be estimated visually, measured with a graduated rod, or with pressure transducers.  Wave
height estimates can also be  obtained from an off-site external source, such as a NOAA buoy.
Turbidity has also been proven to be a useful factor for use in predictive  models.  Turbidity can
be measured with a field turbidimeter or in situ by use of a turbidity sensor.  Models of marine
recreational water sites may also include tides (Boehm and  Weisberg, 2005;  Hou  et al., 2006).
Insolation, a measure of solar radiation, has been  shown  to be a useful  predictor for  fecal
indicator bacteria models, since fecal  indicator bacteria are  sensitive to sunlight (Boehm et al.,
2002). Insolation can be measured using a pyranometer on site or provided by  external sources
(such as NOAA). Rainfall, as well as wind speed and direction, have been included in predictive
models.  These data can be measured  in situ using a weather station or obtained from a reliable
source such as operating meteorological stations,  which are often located at airports (NOAA,
2007).  Streamflow rates from nearby tributaries (USGS,  2007) and effluent discharge rate
information from wastewater treatment  plants may also be useful  factors for inclusion in a
predictive model.  The number of birds at the recreational water might also prove useful factors
for inclusion in  a model.  Some models presently in use in the Great Lakes for water quality
notification use  the amount of biological wrack or  algal mats as model inputs.  Overall, the
factors/variables included in  a  model will be  site-specific.  A thorough review of factors that
might be included in a water quality notification model is outlined in Boehm et al. (2007). Water
quality notification models that are most commonly used are simple heuristic models that relate
rainfall to water  quality (Ashbolt and Bruno, 2003).

Two types of output may be produced by statistical models.  The first and obvious output is the
predicted microbial concentration and its associated confidence limits. A second output variable
is  the probability of  exceeding an appropriate target value; for example, the probability  of
exceeding the single sample  maximum recreational water quality criteria (Francy and Darner,
2006). Either output may be used to issue advisories or closings of a recreational water site.
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6.4.3   Data Needs for Simple Sanitary Investigation Model Development

Because the sanitary investigation model has not been implemented previously for water quality
criteria development, data needs are based on characteristics that are important to models used
for TMDL implementation.  A waterbody manager would  need data on land use within a
watershed, types and numbers of domesticated and wild animals, publicly (and privately) owned
(wastewater) treatment works  (POTW) discharges and  their degree of treatment and effluent
characteristics,  number  and types  of on-site  septic  systems,  type and  age  of sewage
infrastructure, presence of CSO and sanitary sewer overflows (SSO) systems, soil characteristics,
and watershed slope.  At minimum, such  a model could generate a quantitative score of "very
likely" to "not probable at all" regarding the possibility of having human pathogens present.

6.4.4   Cost Estimates

There is a wide range of cost estimates for the  development,  validation, and maintenance of
statistical model programs.  For all programs, the assumption  is that  an  indicator monitoring
program is already in place for the recreational  water  and computer  hardware  and statistical
software are available.  The following are  3 examples of costs for statistical modeling programs
for 2 recreational seasons (60 observations per season), starting from the least to most expensive
programs.

    1.  Using existing data from other  sources, such as meterological data  from the National
       Weather Service (NWS) and wave height data from NOAA.  Expenditures include data
       compilation and model development (200 hours of computer time).
   2.  Using existing meterological data from other sources, measuring turbidity, wave heights,
       and number of birds at the time of sample collection. Expenditures include the purchase
       of  a turbidimeter  and  standards  ($1,200), field measurements (30 hours), and  data
       compilation and model development (200 hours).
   3.  Installing in situ site-specific instruments  for measurements of wave heights, turbidity,
       wind direction  and speed, and rainfall amounts.  Expenditures include the purchase and
       installation  of  equipment (a one-time  cost of  $15,000 to $20,000),  maintenance of
       equipment ($2,000/year for  replacement and manufacturer calibration of equipment and
       80 hours), and data compilation and model development (200 hours).

6.4.5   Understanding the Uncertainty and Measuring Success of Statistical  Models

The natural complexity of environmental systems means that it  is difficult to develop complete
mathematical descriptions of relevant processes, including  all of the intrinsic mechanisms that
govern their behavior.   Model evaluation is defined as the process used to  generate information
to determine whether a model  and  its analytical results  are of sufficient quality to serve as the
basis for decision making (CREM, 2003).  Once a statistical model is constructed, it is important
to describe its usefulness or success.  A  regression model is built using  a "training" data set
comprised of dependent  and independent variables (Boehm et al., 2007).  The ability of the
model to predict the dependent variable  using independent descriptive variable inputs within the
training data set can be described  by  a  root  mean  square error  (RMSE).   A  coefficient of
determination (R2) can also be used and is interpreted as the  percent of the  variation of the
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independent data set described by the model.  However, the workgroup members agreed that this
was not  the best metric for evaluating model performance.  A third metric for testing the
performance of a model is to examine the number of Type I and  Type II  errors that result.
Assuming the null hypothesis is that a recreational water is  in compliance with a water quality
regulation and should be open to the public, a Type I error occurs when a recreational water is
closed or posted with a warning when it should not be (i.e., false positive), while a Type II error
occurs when a recreational water is not posted or closed when it should be based on the water
quality regulation (i.e., false negative).  These two types of errors can be summed to determine
the total errors.   The number  of such errors  is a function of the specific policy used by
recreational water managers in making water quality notification and closure decisions.

Model evaluation must be conducted using a data set with which it was not trained before it can
be applied as a predictive tool.  Model evaluation is defined as the process used to generate
information to determine whether a model  and its analytical  results are of a quality sufficient to
serve  as  the basis for a decision (CREM, 2003).  It can only be completed if an appropriate
evaluation data set of independent and dependent  variables not used to train  the  model is
available. The success of a model  during evaluation is described by  the root mean square error
of prediction, which has the same mathematical formation as the RMSE. The number of Type I
and II errors, as well as the total error rate is also  calculated.  The model's  performance is then
compared with the current  method for assessing recreational water quality  (i.e.,  using the
previous day's measured bacterial indicator concentration).

At  a  Lake Michigan  recreational waterbody  during 2004 (Olyphant, 2004; Pfister,  2007),
swimmers were exposed to a health threat without warning on three occasions and kept out of the
water when  it was safe on only one occasion when a water quality model was used to make
recreational water closure decisions. In contrast, swimmers would have been exposed to a health
threat without warning on  19 occasions  and kept out of the water when it was safe on 12
occasions if daily morning monitoring data alone had been used to  notify the public  of health
risks.

Because every model contains simplifications, predictions derived from the model can never be
completely accurate and the model can never correspond exactly to reality (CREM, 2003).  After
model validation  (e.g., those that  have  been shown to correspond to field  data),  an additional
year of data can be added to the model development process and a new model with another year
of data is developed for use in subsequent years.

The information  about model evaluation presented above is an overview.  The peer  reviewed
literature should always be examined for new ideas and thoughts about model evaluation.

6.5   Research Needs

Research  needs  for simple, statistical  models are  categorized  below  regarding  near-term
activities (2  to 3 year horizon) of immediate relevance to implementation and development of
new or revised rcriteria in recreational waters to long-term research activities, such as elucidation
of processes affecting pathogen/indicator fate and transport, development of non-point  source
models for catchments or watersheds, and deterministic models for TMDL development.   There
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were differences  of opinion among workgroup members  about how important TMDL model
development is for the long-term for criteria development and implementation.

6.5.1   Near-term Research Needs (2 to 3 years)

There is an immediate need to conduct research for development of models that can be used for
water quality notification. Statistical (or empirical) models are most promising for this purpose
because they are relatively cheap  and simple, and readily accessible to most recreational water
quality  managers  (see  Chapter  7).   Statistical  models  link  microbial  concentrations with
meteorological and water quality data/information. Recent research has lead to the development
of useful statistical models for some Great Lakes recreational  beaches (Francy and Darner, 2006;
Francy et al., 2003; Frick et al., 2005; Olyphant, 2005; Whitman and Nevers, 2004; Whitman et
al.,  2006) and marine coastal beaches (Hou  et al., 2006). Although these statistical models have
successfully  predicted  criteria exceedances under  a variety  of  environmental  conditions,
statistical modeling studies must be extended to  a variety of other recreational waters to evaluate
fully the utility of this approach.

Near-term research needs for water quality notification include the following:

    1.  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 due to
       notification errors. Simple, heuristic or  statistical water quality notification models can
       help avoid notification errors (all  5 workgroup members [5/5] agree).
    2.  Immediate research needs include the following:
          a.  Testing whether models can be used to predict health outcomes during upcoming
              epidemiology studies at Doheny  Beach (California) and in  Alabama and Rhode
              Island, and as well as the already  completed epidemiology studies done in  the
              Great Lakes (described by Wade et al.,  2006) (high priority  [5/5]);
          b.  Developing and testing simple notification models on different recreational water
              types with a wide range of sources and  geographical locals (high priority [5/5]);
          c.  Exploring the feasibility of developing regional models that apply to more than
              one recreational water (low priority [5/5]);
          d.  Training  recreational water managers  (high priority [3/5], low priority [2/5],
              there was disagreement on whether this belonged on the research list);
          e.  Creating an excellent user-friendly portable  package for developing local models
              (high priority [5/5]); and
          f.  Developing dynamic  predictive  modeling methods (refers  to  models  where
              variables are constantly  updated  over time) (high  priority  [2/5], medium
              priority [2/5], low  priority [1/5])

1.  Linking statistical models to health  effects.   One  approach would be  to concurrently
conduct modeling studies along with planned epidemiological studies that will be conducted by
EPA and the Southern California  Coastal Water Research Project during the upcoming year in
California,   Alabama,  and  Rhode  Island.    In addition   to measurements  of  microbial
concentrations, appropriate  data   for model  development  should be collected  during  the
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epidemiological  studies (e.g., turbidity,  irradiance, wind speed/direction, wave height, tides,
temperature).

Another  approach would be to  retrospectively  develop statistical  models  for sites of past
epidemiological  studies  in  the  Great Lakes,  where  appropriate data relevant  to statistical
modeling have already been collected  (or can be obtained from existing meteorological data).
For example,  statistical models have been developed  for Huntington Beach, Ohio, and West
Beach, Indiana—both of which are sites  of past NEEAR epidemiological  studies (Haugland et
al., 2005; Wade et al., 2006).

2.  Developing  statistical models for different types  of recreational waters.  To test the
feasibility of the statistical modeling approach, research is needed in recreational waters that are
impacted by different sources of biological contaminants (non-point or point sources such as
POTWs) and that are described by a wide range of meteorological and water quality variables.
Waters that are  significantly impacted by POTWs or non-point  agricultural sources will  be
accorded the highest priority in site selection because past studies have shown that these sources
are most likely to adversely affect human health. Sites located in the following regions should
be considered for this research:

   •   West Coast (open ocean and confined beach);
   •   East Coast (open ocean and confined beach);
   •   Gulf Coast;
   •   inland lakes/reservoirs;
   •   rivers with designated primary contact recreational use; and
   •   tropics and subtropics.

3.  Dynamic approaches to statistical modeling.  Currently used models  are based on long
time-series records that take at least 2 years to obtain.   The regression constant and coefficients
are held  constant when the model is  used to  predict (generally Nowcast)  conditions.  Once
established, the models are changed only at the end of season to incorporate new data.  Other
recent research suggests that model performance may be improved by using a dynamic approach
in which the descriptive variables are updated periodically with data generated within a limited
recent period—usually on the order of 30  to 60 days. Using the dynamic modeling approach, the
predictions  of bacterial concentrations  have  been  significantly improved  (Frick  and Ge,
submitted;  Hou et al., 2006) and the time period for model development may be reduced.  An
alternative  approach would be the development of a sliding seasonal band of data using multi-
year data from the period surrounding the  date of interest.  Additional research is  required to
refine this approach, either though use  of previously obtained data sets or data obtained at sites
that will  be used for the first two activities (i.e., linking statistical  models to health  effects and
developing statistical models for different types of recreational waters).

4.  Communicating and training  modeling techniques.  Various activities  can improve the
communication of modeling techniques and results to the public and training recreational water
managers, including the following:
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    •   creating a user-friendly portable package for developing local models;
    •   training for running statistical models for recreational water managers; and
    •   including recreational water managers on the decision process and polling them regarding
       their perception of its usefulness/feasibility.

Training is an important component towards acceptance and implementation of statistical models
by recreational  water managers and public health agencies.  In a November 2003 workshop held
as part of the Great Lakes Beach Association Annual Conference in Green Bay, Wisconsin,
recreational water managers expressed as a high priority the need for informed training on
statistical  models and other recreational water monitoring activities. Similarly, training is being
provided by EPA Region 5 on statistical model and sanitary survey (investigation) development
in April 2007 at the request of recreational water managers.

5.  Explore the feasibility of developing regional models (e.g., for  southern Atlantic coast
recreational waters).  At present, simple water quality notification models are site-specific.  The
feasibility of using a regional  scale model that predicts water quality regionally, within a large
waterbody, for example, should be explored.

Near-term research needs (next 2 to 3 years) for sanitary  investigation models include the
following:

    1.  Simple,  heuristic, statistical/conceptual models that correlate watershed activities (e.g.,
       presence of treatment plant effluents, agricultural activities, domesticated animals) and
       attributes (e.g., slope,  soil type, climate,  soil moisture)  can be used to determine the
       probability of a waterbody having inputs of human pathogens (all [5/5] agree).
    2.  Research in the near-term should be carried out to  better understand  how watershed
       activities and  attributes relate to pathogen presence  in  streams and receiving waters,
       including the following:
          a. factors that  modulate  septic tank  impact on  waterbodies  (high priority  [1/5]
             medium priority [1/5], low priority [3/5]);
          b. factors that  modulate  contributions of animal  wastes to pathogen  and pathogen
             loads to waterbodies (high priority [5/5]);
          c. sources in urban landscapes such as broken/leaky sewer pipes, CSOs, stormwater
             and urban runoff (high priority [5/5]); and
          d. effect of geographical and climatic setting on non-point source delivery (high
             priority [5/5])

6.5.2   Longer-term Research Needs (8 to 10 years)

A variety of research needs are required to be able to  develop an excellent model that would
allow prediction of fecal indicators or human pathogens.  Additionally, important sources, and
fate and transport processes will need to be elucidated.  These  research needs will require a
longer time horizon for completion and are summarized below.
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    1.  Processes that affect fate and  transport of pathogens  and fecal indicators for
       incorporation into deterministic models and improving statistical models indicators.
       This long-term research  effort involves the  development  of data and descriptors of
       processes that are required in deterministic models that predict fate  and transport effects
       on pathogen concentrations in recreational waters.  Process information can also be used
       to  help define appropriate variables to use in statistical  models.  Such research would
       focus on partitioning of microorganisms to  suspended and bottom sediments and sands,
       mortality of  pathogens and indicators, zooplankton grazing  on fecal indicators  and
       pathogens, and the possibility of bacteria proliferation in the environment. Some of these
       processes are shown in Figure 5. In addition to these processes, a better understanding of
       mobilization of pathogens and pathogen indicators from sources within a watershed (i.e.,
       from animal  feces) and  source strength from  POTWs  and CSOs  are needed  (high
       priority [5/5])

    2.  Research  on GIS layers  relevant  to  modeling.  In order to develop viable models,
       recent and relevant  GIS data need to be readily available and usable for models (e.g.,
       POTW locations, recent land use categories, storm sewer locations).  Digital Watershed
                              Microbe

                              Predator

                              Inactivated microbe
              Particle

              Particle-bound
              microbe
 A Desorption    |nactivation
•b
                         Resuspension
                                                   Sedimentation
           Sediment
                        Predation
                                         Growth
                                                        Inactivation
                                                                   Water Column
                                                                   Transport
       Figure 5.  The Possible Fates of Microbes (Fecal Indicators and Pathogens) in
       Environmental Water and Sediment (the fate of nucleic acids may be different;
       this figure does not include those sources).  SOURCE: Adapted from Olivieri et
       al. (2007).
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       is  one example of a  GIS-based software that can be  used to provide inputs for
       deterministic models such as L-THIA (high priority [1/5], medium priority [4/5], [1/5]
       does not think this is a research need).

    3.  Combining deterministic models with statistical models. This research involves using
       outputs from deterministic models as inputs for statistical models that would be used for
       water  quality  notification and  sanitary  investigation  purposes (high priority [0/5],
       medium priority [5/5])

    4.  Forecasting using statistical models.  This research will seek to expand current efforts
       (e.g., by Frick and Ge, submitted) to use forecasted variables (such as wind speed and
       direction, precipitation, wave height, and turbidity, if available) to forecast concentrations
       of biological contaminants in recreational waters (high priority  [2/5], medium priority
       [1/5], low priority [2/5])

    5.  Development of deterministic models of  pathogen and  fecal indicators for criteria
       implementation and development (high priority [3/5], medium priority [2/5] there
       was concern that these would not be really used by recreational water managers and that
       this is already being done if resources permit).

References

Ashbolt, NJ;  Bruno, M.  2003. Application and refinement of the  WHO risk framework for
recreational waters in Sydney, Australia. Journal of Water and Health 1(3): 125-131.

Boehm,  AB;  Whitman,  RL;  Nevers,  MB;  Hou,  D;  Weisberg,  SB.  2007.  Now-Casting
Recreational Water Quality. In: Wymer, L;  Dufour, A. (eds.) Statistical Framework for Water
Quality Criteria and Monitoring. In press.

Boehm, AB; Grant, SB; Kim, JH; Mowbray, SL; McGee, CD; Clark, CD; Foley, DM; Wellman,
DE. 2002. Decadal and shorter period variability of surf zone water quality at Huntington Beach,
California. Environmental Science and Technology 36: 3885-3892.

CREM  (Council  for Regulatory Environmental  Modeling).  2003. Draft Guidance  on the
Development, Evaluation, and Application of Regulatory Environment Models. Washington, DC:
US EPA.

Ferguson, CM; Croke, BFW. 2005.  Deterministic model  to  quantify  pathogen and  faecal
indicator loads in drinking water catchments.  Pp. 2679-2685 in: Zerger, A; Argent, RM (eds).
MODSEVI 2005 International Congress on Modelling and Simulation. Modelling and Simulation
Society   of   Australia    and   New   Zealand,    December   2005.   Available    at:
http://mssanz.org.au/modsim05/papers/ferguson.pdf.

Ferguson,CM; Croke, BFW; Beatson, PJ; Ashbolt, NJ;  Deere, DA. 2007. Development of a
process-based model to predict pathogen budgets for the Sydney  drinking water catchment,
Journal of Water and Health 5(2): 187-208.
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Fong, TT;  Griffin, DW;  Lipp, EK. 2005. Molecular assays  for targeting human and bovine
enteric viruses in coastal waters and their application for library-independent source tracking.
Applied and Environmental Microbiology 71(4): 2070-2078.

Francy, DS; Darner, RA. 2002. Forecasting Bacteria Levels at Bathing Beaches in Ohio. USGS
FS-132-02.

Francy,  DS;  Gifford, AM; Darner, RA. 2003. Escherichia  coll at Ohio  Bathing Beaches-
Distribution, Sources, Wastewater Indicators, and Predictive Modeling. USGS WPIR 02-4285.

Francy, DS; Darner, RA.  (2006) Procedures for Developing Models To Predict Exceedances of
Recreational  Water-Quality Standards at  Coastal Beaches.  USGS  Techniques and Methods
Report 6-B 5.

Francy,   DS;  Lis,   J.   2007.   Ohio   Nowcasting   Beach  Advisories.   Available   at:
http://www.ohionowcast.info.

Frick, WE; Francy,  DS; Darner,  RA;  Ge,  Z.  2005.  Developing  site-specific  models  for
forecasting bacteria levels at coastal beaches. Proceedings of the 18th Biennial Conference of the
Estuarine Research Federation. Norfolk, Virginia.

Frick, W;  Ge, Z.  Nowcasting and forecasting concentrations  of biological contaminants at
beaches: Case study with E. coli. Submitted.

Handler, NB; Paytan, A;  Higgins, CP; Luthy, RG; Boehm, AB. 2006. Human development is
linked to multiple water  body impairments along the California  coast. Estuaries and Coasts
29(5): 860-870.

Haugland,  RA; Siefring,  SC; Wymer, LJ; Brenner, KP; Dufour, AP. 2005.  Comparison of
Enterococcus  measurements  in freshwater  at  two  recreational  beaches  by  quantitative
polymerase chain reaction and membrane filter culture analysis. Water Research 39(4): 559-668.

Hou, D; Rabinovici, SJ; Boehm, AB. 2006. Enterococci predictions from a partial least squares
regression model  can improve the efficacy of beach management advisories. Environmental
Science and Technology 40(6): 1737-1743.

Kay, D; Wyer, M; Crowther, J;  Stapleton, C; Bradford, M; McDonald, A; Greaves, J; Francis, C;
Watkins, J. 2005.  Predicting faecal indicator fluxes using digital land use  data in the UK's
sentinel Water Framework Directive. Water Research 39(16): 3967-3981.

Kay, D; Aitken, M; Crowther, J; Dickson, I; Edwards, AC; Francis, C; Hopkins, M; Jeffrey, W;
Kay, C; McDonald, AT;  McDonald, D; Stapleton, CM;  Watkins, J; Wilkinson, J; Wyer, M.
2007. Reducing fluxes of faecal indicator compliance parameters to bathing waters from diffuse
agricultural sources, the Brighouse Bay study, Scotland. Environmental Pollution 147: 139-149.
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Kim,  KH;  Grant, SB. 2004. Public mis-notification of coastal water quality: A probabilistic
evaluation  of posting errors at Huntington Beach,  California. Environmental Science  and
Technology 38: 2497-2504.

Kumar, A;  Jain, A. 2006. Assessment of neural network technique for estimating fecal  coliform
based on hydrologic and  climatic data. Geographical Research Abstracts 8: 01622.

Mallin, MA; Williams,  KE; Esham, EC;  Lowe, RP.  2000.  Effect of human development on
bacteriological water quality in coastal watersheds. Ecological Applications 10(4): 1047-1056.

NOAA (National  Oceanic and Atmospheric Administration.  2007. National Virtual Data
System—National Climatic Data Center. Asheville, NC: NOAA.

Neelakantan, TR; Lingireddy, S; Brion, GM. 2002. Effectiveness of different artificial neural
network training  algorithms in  predicting  protozoa risks in surface waters.  Journal of
Environmental Engineering 128(6): 533-542.

Nevers, MB; Whitman,  RL. 2005. Nowcast modeling of Escherichia coli concentrations at
multiple urban beaches of southern Lake Michigan. Water Research 39(20): 5250-5260.

Olivieri, AW; Boehm,A;  Sommers, CA;  Seller,  JA; Eisenberg,  JNS; Danielson, R.  2007.
Development of a Protocol for Risk Assessment of Microorganisms in  Separate Stormwater
Systems. Water Environment Research Foundation, Project 03-SW-2, Final Project Report. In
press.

Olyphant, GA. 2004.  Statistical basis for predicting the  need for bacterially  induced  beach
closures: Emergence of a paradigm? Water Research 39(20): 4953-4960.

Pfister,  M.  2007. Earth 911  and SwimCast for Lake County,  IL Beaches.  Available at:
http://www.earth911.org/waterquality/default.asp?beach_id=8488&cluster=17.

Siewicki, TC; Pullaro, T; Pan, W; McDaniel, S; Glenn, R; Stewart, J. 2007. Models of total and
presumed wildlife sources of fecal coliform bacteria in coastal ponds. Journal of Environmental
Management 82:120-132.

USGS (U.S. Geological Survey).  2007. Real-Time Water Data for the Nation. Available at:
http://waterdata.usgs.gov/nwis/rt.

US EPA (U.S. Environmental Protection  Agency).  1986. Ambient Water Quality Criteria for
Bacteria - 1986. EPA440/5-84-002. Washington, DC: US EPA.

US EPA. 2002. National Beach Guidance and Required Performance Criteria for Grants
Appendix K: Predictive Tools. EPA-823-B-02-004. Washington, DC: US EPA.
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Vereen, E,  Jr.;  Lowrance,  RR;  Cole,  DJ; Lipp, EK. 2007.  Distribution  and ecology  of
campylobacters in coastal plain streams (Georgia, United States of America). Applied and
Environmental Microbiology 73: 1395-1403.

Wade, TJ; Calderon, RL; Sams, E; Beach, M; Brenner, KP; Williams, AH; Dufour,  AP. 2006.
Rapidly measured indicators  of recreational water quality are predictive of swimming associated
gastrointestinal illness. Environmental Health Perspectives 114(1): 24-28.

Whitman, RL; Nevers, MB.  2004. Escherichia coll sampling reliability at a frequently closed
Chicago beach:  Monitoring  and  management  implications.  Environmental  Science and
Technology 38(16): 4241-4246.

Whitman, RL, Nevers, MB, Byappanahalli, MN. 2006. Examination  of the  water shed-wide
distribution of Escherichia coli along southern Lake Michigan: An integrated approach. Applied
and Environmental Microbiology 72(11): 7301-7310.

Whitman, R. 2007. Project S.A.F.E. Available at: http://www.glsc.usgs.gov.

WHO   (World  Health  Organization).   2003.   Guidelines  for  Safe  Recreational   Water
Environments. Volume 1 Coastal and Fresh Waters. Geneva, Switzerland: WHO.
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                                CHAPTER 7
                      IMPLEMENTATION REALITIES
         Lee Dunbar, Chair, Connecticut Department of Environmental Protection
         Thomas Atherholt, New Jersey Department of Environmental Protection
         Bart Bibler, Florida Department of Health
         Lawrence  Honeybourne,  Orange  County  Health  Care  Agency,  Santa  Ana,
          California
         Charles Noss, USEPA
         James Pendergast, USEPA
         Michael Tate, Kansas Department of Health and Environment
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EPA requests that experts consider implementation realities when providing input to all specific
and general questions throughout this document.

The Implementation Realities workgroup members were charged with providing input to EPA
and the experts participating on the other six workgroups concerning the practical implications of
incorporating any proposed changes to the recreational bacteria criteria into State Water Quality
 Standards (WQS) and subsequent impacts on existing water quality management programs. To
this end, the  workgroup members met frequently  with  and actively  participated  in the
deliberations of the other workgroups over the course  of the workshop.   Implementation issues
and concerns are therefore incorporated into the individual workgroup chapters throughout these
proceedings. This chapter provides a summary of the major areas of concern identified by the
Implementation Realities workgroup during the deliberations  resulting  from the workgroup's
internal discussions as well as discussions with other workshop participants.

At the most basic level,  the success of implementing  any  new initiative depends on providing
resources and guidance that are adequate to accomplish the stated objectives.  Where additional
effort is needed,  either additional resources must be obtained or  existing resources must be
diverted from other activities. Workgroup members attempted to evaluate resource needs as a
critical   component  of  implementing  new  bacteria  criteria  across  a broad spectrum  of
programmatic responsibilities from conducting necessary research to educating stakeholders and
gaining acceptance of the public and regulated entities of program changes, to actual impact on
the day-to-day implementation of water quality management programs.

The results  of the discussions are presented in three  sections.  First, an evaluation of the four
principal program areas where recreational bacteria criteria are currently employed:  (1) water
quality  beach notification and advisory programs; (2) National Pollutant Discharge Elimination
 System  (NPDES) permitting, including  regulation of wastewater  treatment facilities,  urban
stormwater, and combined sewer overflow and sanitary sewer overflow  (CSO/SSO) discharges;
(3) monitoring and assessment programs required for compliance with Clean Water Act (CWA)
 §303(d) and §305(b) purposes; and (4) development of total maximum daily loads (TMDLs) for
waters identified as not meeting State WQS.  The second section provides  an evaluation of the
implementation concerns that must be  addressed that relate  specifically to  three potential
approaches for the development of new or revised recreational water quality criteria. The third
and final section identifies the specific areas of research that workgroup members considered to
be most critical to facilitating implementation efforts.

7.1    Application to Specific Program Areas

7.1.1  Beach Monitoring and Water Quality Notification Programs

 The objective of this program  is to provide  accurate and timely information to the public
regarding the health risks associated with participating in  recreational activities at marine and
freshwater beaches.  Significant concerns have been expressed regarding both the accuracy and
timeliness of the information currently provided.
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The most pressing need for regulatory authorities who conduct beach monitoring programs is to
get better information to the public as quickly as possible regarding the safety of the recreational
water.  There is currently a minimum 24 hour delay between the time when a water sample is
collected, tested, and when the results of the test are available. Thus, decision makers only know
what the quality of the bathing water was like yesterday.

    "Rapid Tests"

Research in the past few years has resulted in the development of molecular-based tests that can
provide results  in just a few hours following the initiation of the test  compared to 24 hours for
the currently used culture-based tests.

Rapid tests have several benefits.  They shorten the time from when an unsafe water condition
occurs (an "exceedance") to when the test reveals the existence of an exceedance.  This provides
a capability to shorten the time it takes to post an  advisory or to close the beach during unsafe
conditions.  The  reduced test period thereby  reduces the public health risk.   The shorter test
period also shortens the time it would take to remove the advisory and/or reopen the beach when
water quality returns  to a safe condition.   Thus, the period of "loss  of beneficial use" is  also
reduced. Because test results can be obtained in a shorter period, it is possible that they could be
used to aid fecal pollution source identification efforts such as in identifying a problem  in a
specific location by enabling more samples to be analyzed in a shorter period  of time.

Although there is a desire to use  the new, rapid  tests in beach monitoring programs,  several
issues related to their  use must first be resolved. First and foremost, it must be shown that these
new "molecular" methods provide a level of human health  protection equal to or above that
provided by the currently used tests.  States need to know that there is a beneficial reduction in
illness to justify the costs of adopting and implementing a new test methodology.

While rapid tests are sometimes referred to as "real-time" tests, they are not in fact real-time tests
as there is still a delay of several hours between water sampling and test results.  The public may
still be exposed to potentially unsafe water for some period of time, albeit likely a shorter time
period compared  to current culture-based methods used  to measure indicator organism levels.
The rapid tests will not shorten the time required to collect water samples and deliver them to the
test laboratory  (typically 4  to 5 hours  or  longer), nor will they shorten the time required to
convey test results to the appropriate authorities and the public (1  to 2 hours or more).

Many States only have the resources to sample periodically (e.g., weekly, monthly) as opposed
to daily. The new tests are not likely to provide authorities with resource savings sufficient to
analyze water quality more frequently.  However, the ability to obtain test results faster may
raise the expectation of the public or regulatory mangers that, since the tests are faster, additional
samples  can  or should be collected and tested—even when this may not  be possible due to
resource constraints.   Taking full advantage of the  benefits associated  with more rapid tests will
likely require additional resources for increased monitoring.

Before any new test can be used broadly, the EPA will have to adopt and validate a standardized
method for its use.  State and local public health officials use the results of monitoring to make
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health-based decisions to close  or open a beach, or to issue or lift a beach advisory.  These
officials need to know that the  analytical method they use provides reliable results; therefore,
they only endorse methods that have already been validated by EPA.

Further, to be able to bring a faster test into routine use, issues related to test equipment, training,
laboratory capacity, and certification of laboratories will need to be resolved. The initial capital
cost and any ongoing operation and maintenance costs need to be calculated and compared to
that of the currently used tests.  Regardless of how "good" the more rapid tests are, if they are
too expensive, regulatory authorities may not be able to afford them.

In addition,  because the test endpoints of molecular-based tests are different than culture-based
tests, a new regulatory scheme may need to be adopted to accommodate the new water quality
criteria. See the discussion in Section 7.1.2 for further information on this topic.

For the public and local authorities, a period of time may be required to gain "acceptance" of the
new indicator.

In general, any change in current monitoring practices (e.g., sampling type, frequency, location)
necessitated by a change in recreational water quality criteria will need to be carefully considered
relative to benefits offered because  it will involve resource issues  and many implementation
concerns.

    Predictive Modeling

Changes in  microbial indicator counts in recreational waters are typically  controlled to a large
extent by  a variety of meteorological  and water quality factors.  Data for many of these factors
(e.g.,  wind,  rainfall,  etc.) can  be  obtained in  real or near-real time.   By  monitoring and
identifying  which of these factors control indicator count changes,  it is  possible to create
"predictive models" (see Chapter 6).  Such models are essentially mathematical  equations that
have the  "controlling"  meteorological and/or water quality parameters  as components.   A
"robust"  model that  is  validated by  comparison of predicted indicator  concentrations to  a
sufficient  number of actual concentrations is able to successfully predict, within a stated degree
of precision, when  unsafe water conditions will exist more accurately than the  currently used
culture-based assays are able to do.

Predictive modeling offers great  promise because it estimates when there may be a problem prior
to the bather exposure.  The use  of predictive models may also reduce the need for rapid testing.
Furthermore, they can be employed  daily, providing information beyond that available from
periodic microbial monitoring.   However, it is important to note that predictive models are not
themselves criteria.  Predictive models are tools that can be used to evaluate compliance with
criteria.

Models are only as good as the data used in their construction. If critical data are not available, a
valid model cannot be developed until those data are obtained.  As discussed in  Chapter 6, the
amount of data, especially microbial monitoring data, required to develop a predictive model
within a stated confidence level may be significant. In general, model development may require
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significant time and  resources  depending primarily on the  availability of data on  indicator
densities and  associated predictive  variables (e.g., antecedent rainfall, wind direction,  wave
height, etc.).

Currently developed predictive models appear to be site-specific.  A predictive model developed
for one beach or location is not likely to be usable at other  beaches or locations because the
effect of a predictive  variable such as wind direction on indicator densities will be different at
each beach.  Therefore, for each "problem" beach or location, a separate model (i.e., set of
predictive equations) is likely to be required.

Competing financial resources may make modeling a low priority.  For example, limited  funds
may have to be used for higher priority tasks such as improving impaired waters (e.g., fecal
source identification).

Any  proposed  use  of modeling  results  for  compliance   purposes  is likely  to  present
implementation difficulties.  Model  results may not be always accepted as "proof of a  water
quality  standards violation because  of the inherent uncertainty associated with model results.
That is, regulators are likely to  require actual monitoring data rather than modeling output for
compliance purposes,  particularly if non-compliance may lead to legal  enforcement action.
Regulators as well as members of the public often perceive monitoring as accurate and modeling
as estimates.

Statistical models are currently used in some States to assess compliance with their water quality
standards for purposes other than beach monitoring. If there is a change in the  criteria (as would
occur if a new indicator is adopted) then corresponding model would have to be modified, which
would require additional resources.

It is important to note that modeling should not supplant routine water quality monitoring, which
will always be needed to detect  unanticipated events such as a sewer line break.  Thus, regular
monitoring provides an ongoing, direct measure of microbial water  quality.   Monitoring also
provides data to help improve the precision of model predictions.

    General Considerations

Workgroup members felt that any new or revised recreational water quality criteria need to allow
for a binary (pass/fail) decision (e.g., close or not close a beach), must be a numeric, and must be
based on a health risk determination for water quality notification/closure purposes.  The criteria
for reopening a closed beach or removing an advisory should be the same as that used for the
initial  closure or  advisory.  New or revised criteria must  be  expressed in a way that the
authorities using the criteria are  able to fully explain the criteria and their health risk basis, in a
readily understandable way to the public.

New or revised criteria should have some "flexibility"; for example, there may be State-specific
circumstances and the criteria will need to be able to be used  in all such circumstances.  At the
same  time, the new or revised criteria need consistency so that the public has confidence that
their health is being protected.
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Any new or revised criteria should be tied to a specific method unless "equivalency" of the new
method  to  a previously used  (and validated)  method can  be  demonstrated to   facilitate
implementation (see Chapter 3 for further information).

The development of guidance to implement new or revised criteria  should occur simultaneously
with the development of the criteria. The implementing authorities will need assurance that the
new criteria will be effective in ensuring that public health goals are  met.

Finally, the successful implementation of new or revised criteria will very likely result in the
need for increased funding for microbial source tracking (see also Chapters 2  and 3) and for
beach management programs.

7.1.2  NPDES Permitting Programs

The purpose of the NPDES permitting program  is to insure that point source discharges  of
pollutants to waters of the United States achieve the statutory required level of treatment and do
not cause waters to exceed State  WQS after discharge.  This is accomplished by imposition of the
more stringent of either technology-based or water quality-based limits on discharge quality and
mandating discharge monitoring at a frequency adequate to insure compliance with permit limits
and conditions.

    Tiered Approach

Water quality criteria might be expressed in a tiered approach; that is,  that the  criteria include
multiple attributes, each of which apply for a specific purpose.  With respect to NPDES permits,
the tiered approach should be workable  as long as one  attribute of the criteria is specifically
developed for NPDES requirements. This would necessitate choice of a pathogen indicator that
achieves NPDES needs (see more below).

In addition, NPDES effluent limits are developed with an implicit exceedence rate.  NPDES
permitting  guidance for water  quality-based  effluent  development is based on a wasteload
allocation that is  calculated  based on an  exposure condition that represents  the upper 99th
percentile of conditions (e.g., conditions  occurring under rare low flows such as the 7Q10 [the
lowest streamflow for 7  consecutive days that occurs on average once every 10 years]) when
point source discharges have the greatest impact on water quality conditions.  As a result, it is
important that water  quality criteria include an allowable  exceedance frequency  to  facilitate
permit limit derivation.  This is particularly important for deriving permit limits for pathogen
indicators in wet weather conditions because the flow conditions at  the time of discharge  can be
extreme and represent rarely occurring situations.

    Pathogen Indicators

Changes in pathogen indicators from the current ones (E. coli and enterococci) will significantly
affect implementation, especially if the change results in a different indicator  being  used for
TMDL modeling than for permitting or uses an indicator that cannot reflect  the efficacy  of
wastewater (sewage) treatment practices  (disinfection).  At a minimum, the indicator  used for
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NPDES permitting needs to be sensitive to disinfection  so  that the permitting authority can
determine that the NPDES regulated facility is adequately disinfecting its discharge.  If the
indicator cannot  do so, then there  will be  a need for different indicators for ensuring the
discharge achieves water quality standards and the wastewater is properly disinfected.  Another
way to accomplish this is to develop an approach that translates between the various indicators.

    Analytical Methods

There  is concern that  molecular-based methods may not adequately verify  that wastewater
disinfection has  been  effective.   This  concern is based on research  that shows the qPCR
(quantitative polymerase chain reaction) signal does not decrease post-chlorination.  Many State
public health  codes  require disinfection of human waste and the analytical method  used for
NPDES permitting needs to be able to measure disinfection.  As a result,  a  molecular-based
method may not be suitable to fulfill all NPDES needs.

It is also important  for implementation that  the analytical methods be  tested  in a wastewater
matrix and approved for use in wastewater.  NPDES regulations require that effluent monitoring
be conducted using either an EPA-approved analytical method or an analytical method  specified
in the permit.   In the latter situation, the permit documentation needs to defend the use of the
method.  However,  many States  do not have the technical experience  to defend analytical
methods or have legal restrictions on the use of alternative methods and thus must rely  solely on
use of EPA-approved methods.

    Resources

Many NPDES regulated dischargers conduct analysis of their wastewater on-site. The existing
laboratory  expertise  of these dischargers may not be sufficient to conduct analyses for new
pathogen indicators (e.g., molecular-based methods).  The start up cost of purchasing equipment
for conducting the new analyses and additional training for staff poses a  resource drain for both
the dischargers and the regulatory authority that must provide  oversight.  Should the dischargers
choose to contract out their laboratory analysis, they will need to pay to  ship the samples to the
contract laboratories, which is also a resource drain.

Finally, many states require that laboratories be certified for analysis with  certification being
specific to the parameter being analyzed. Therefore, States will need to  amend their laboratory
certification program to include the new pathogen indicators.  This is also a resource drain on
States.

7.1.3  Monitoring and Assessment for CWA §303(d) and §305(b)

The purpose of this program is to provide an accounting of the condition of the  Nation's waters,
identify those  that do not meet current State WQS for focused mitigating action, and to track
progress in improving the overall quality of the Nation's water resources.

Assessment and  listing based  on the current ambient water quality criteria (AWQC) have
disproportionately focused  State resources on what are often perceived as minimal to non-
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existent public health issues.  States have expressed frustration at being effectively handcuffed
by strict application of the criteria and the inability to adjust assessment findings based on other
data indicating the health risk is significantly  lower than implied by the criteria exceedance.
Such factors include evidence that elevated indicator levels are not due to human sources of fecal
contamination and hydrologic  factors that preclude recreational exposure, such as during or
immediately after  high rainfall events. Areas where improvements can be made in the new or
revised criteria and implementation guidance associated with the criteria includes monitoring,
criteria, guidance, and (inland) flowing waters.

   Monitoring

Workgroup members felt that new or revised recreational AWQC must include a clear discussion
regarding linkages between an advisory/closure decision at  a beach and assessment  of use
attainment. Beach advisories/closure  decisions  may, but need not necessarily, be linked to such
assessments.  There may be instances where beach advisories or notifications are made based on
models, or special  circumstances (such as sewer line breaks) that should not be counted as non-
attainment for assessment purposes. In a  similar vein, if the beach advisory regulations are more
stringent than State WQS, the advisory  in and of itself should not  constitute non-attainment
unless the State chooses to list that beach  as impaired on that basis.

   Ambient Water Quality Criteria

Alternative AWQC or methodologies that more precisely define health risk would be highly
useful  in improving assessments—in particular indicators  of human versus nonhuman pathogens.
The criteria  and implementation guidance need to recognize the  potentially lower risk of
pathogens from nonhuman sources and provide a way for addressing  and  discounting pathogen
and indicator data not associated with  anthropogenic sources of fecal contamination.

The criteria must also  be sufficiently flexible for assigning attainment of use based  on limited
data sets, particularly  for inland waters.  Often, States  only  collect data on a monthly, bi-
monthly, or annual basis and compare these  data to previously  collected  data to assess trends.
The problem  will be exacerbated for assessment purposes if new or revised criteria are adopted.
It could take years  to develop a statistically significant data set.

If the format  of the new or revised criteria requires a specific number of samples to be collected
in a set timeframe, States will be challenged as they are with the current criteria (e.g., 5 samples
over a 30-day period).  Criteria that allow assessment samples collected at any frequency to be
statistically manipulated to the appropriate exposure frequency would allow States to maintain
their current monitoring approaches while appropriately applying the criteria.

Also, for ease of State implementation, new or revised criteria need to allow for some reasonable
excursion frequency.  Criteria expressed  as a percentile value (e.g., cannot exceed criteria more
than x% of time) would provide an incentive to conduct additional sampling so as to not have the
assessment rely  on one  or  two samples and would facilitate implementation for assessment
purposes.
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If the  European  Union  (EU; EP/CEU,  2006) or World Health  Organization  (WHO,  2003)
approach for criteria development is followed, there needs to be a clear distinction between the
criteria that is needed to protect  human health and what is  considered  to be supplemental
guidance.  For instance, is it possible to have a "good" beach or a "very good" beach and still be
considered non-impaired? Apparently, "good" meets the criteria while "very good" is a desired
higher level of microbial water quality.  Such discussion should be in supplemental guidance
rather than in the criteria.

If a rapid  method is  selected as the indicator,  the speed of a rapid method offers no additional
benefit relative to assessment, unless the rapid method provides more precision/better protection
to benefit public health.  Therefore, a rapid method may offer the benefit of more rapid water
quality notification,  but has little  positive effect on the  overall assessment  process that is
conducted on data collected over a 2 year period.

Workgroup members expressed concerns with establishing a new or revised recreational water
quality criteria linked to  a sanitary  investigation.  If a WHO-type criteria model is chosen that
includes use of a sanitary investigation to modify the criteria and allow for nonhuman sources of
fecal contamination,  the frequency of performing that investigation would need to be identified
in assessment guidance.  There was a strong preference among workgroup members that the
frequency be  longer than the two  year assessment cycle for State's issuance of assessment
information pursuant to §303(d) and §305(b) of the federal CWA.  The available information for
the sanitary investigation did not specify the frequency for repeating such investigations.

Lastly, for assessment purposes, there needs to be some way to translate between previously used
indicators and any new indicator(s) so information  from past monitoring is not lost.  If a
"translator" is not available, it might take several years to build up enough information to
conduct a  statistically valid assessment for pathogen indicators.

    Guidance

If new criteria indicator/methodology  combinations are adopted,  issuance of guidance for
implementation will  be imperative.  With the likelihood of rapid molecular-based test methods,
sanitary investigations, and  so on,  guidance will need to accompany the criteria to help  States
understand how to apply the new or  revised criteria and thus achieve State acceptance.

   Flowing Waters

Flowing freshwaters (e.g., streams,  rivers) present some unique challenges that have not been
addressed with previous  epidemiological studies of recreational waters.   Therefore, if new or
revised criteria include application to flowing freshwaters, consideration needs to be given to an
allowance for different values/applications of the criteria to reflect the differences in hydrologic
regime (e.g., extreme high flows) through one of the following:

    •   higher criteria that applies in extreme events; or
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    •   changes to the use/criteria when the use is not taking place (e.g., when recreation is
       unlikely to occur such as during winter months or during or immediately after heavy
       rainfall).

Lastly, an indicator applicable to flowing freshwaters needs to be identified.  As stated elsewhere
in these  proceedings, E. coli appears to be a more appropriate freshwater indicator  of fecal
contamination than enterococci.  E. coli are a subset of fecal coliform bacteria while enterococci
bacteria are a separate group of enteric bacteria.  More recent water quality data generated using
E. coli can be more easily compared to earlier water quality data generated using fecal coliform
bacteria than can more recent water quality data generated using enterococci bacteria.

7.1.4   Total Maximum Daily Load Program

The purpose  of  this program  is to  establish  the maximum pollutant load that a  specific
waterbody can assimilate  and  apportion  that  load among sources of that  pollutant to the
waterbody, leading to the development of a management plan that when fully implemented will
result in reducing those loads to the extent that State WQS are achieved and maintained.

TMDLs for bacteria designed to achieve consistency with the current (US  EPA, 1986) criteria
are typically  difficult to  develop and explain  to  stakeholders because  expressing pollutant
loadings of bacteria  or pathogens in  terms of  mass is  nonsensical.  Pathogens  or pathogen
indicators are  not measured as mass  but rather as cell counts (e.g., colony forming units [cfu]).
Developing wasteload allocations for point  sources and load allocations for non-point sources in
mass units does not make sense to the vast  majority of TMDL practioners and those responsible
for implementing bacteria  TMDLs.  For this reason, alternative means of expressing loading
reductions (e.g.,  "percent reduction," "load duration  curve-based,"  "reference watershed"
methods) have been used by many States. TMDL development for waters impaired by excessive
indicator bacteria densities is further complicated in that the necessary  load reductions are
typically strongly linked to  hydrologic factors and intermittent sources such as stormwater
runoff.  Establishing a static steady-state design  condition, as is frequently done for other types
of pollutant impairments, is not possible for bacteria due to the significant wet weather event-
driven characteristics of many bacteria-impaired waters.

Workgroup members viewed criteria expressed  in numerical terms  as a practical  necessity to
implementing any revised recreational use  criteria in TMDL programs due to  the  need to
quantify  loadings. Implementation realities dictate that the criteria be expressed in terms that
facilitate calculation of an  acceptable  daily loading under a range of hydrological conditions.
The criteria has to be a number (as opposed to a category/classification) to make implementation
in TMDL programs feasible.  The workgroup experts expressed a diversity of opinions  over the
benefits of a  geometric mean or other statistic versus single sample maximum criteria  with
specified exceedance frequency for water quality assessment and TMDL purposes.  Some prefer
use of single  sample maximum (SSM) while others prefer geometric mean largely reflecting
current practice in their particular State. If the new or revised criteria are expressed as  a single
value, the benefits of allowing for that value to be exceeded at some stated frequency for TMDL
and assessment purposes  cannot be overstated.  EPA should expect intense  resistance from
Sstates if future criteria guidance proposes criteria expressed as a "never to be exceeded" value.
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An acceptable exceedance frequency is critical to facilitate design of treatment requirements and
best management practices (BMPs) to implement the  TMDL as  well  as  accounting for rare
extreme  event-driven  conditions not  practical to mitigate.   Providing  States  (and  other
stakeholders)  with  evidence that the  criteria incorporate flexibility  to  accommodate  the
variability inherent in bacterial densities in natural systems would greatly facilitate acceptance
and subsequent implementation efforts.

Criteria that distinguish between human and nonhuman sources of fecal contamination would
also make TMDL development significantly easier.  The  ability to make  allocation decisions
would be enhanced and public acceptance of the TMDL implementation requirements would be
achieved much more readily if additional confidence could be provided in estimates of source
category loading.  Further, the ability to adjust TMDLs based on more accurate source separation
and to make allowances that "discount" the contribution of certain lower risk sources (e.g., non-
anthropogenic) or sources from which the contributed risk may be lower (e.g., wildlife) would
encourage States  to  move  forward to  adopt the  criteria  into their WQS.   If the criteria or
implementation protocol includes a sanitary investigation there should be guidance provided to
encourage consistency in sanitary investigation methodologies among  States.  This guidance
might be a combination of minimum expectations and general framework for what constitutes an
acceptable sanitary investigation.  A mandate to provide confirmation  of investigation results
through  alternative  means  (e.g.,  microbial  source tracking,  use of more  human-specific
indicators) may also be acceptable provided the  cost and technical  difficulty are not prohibitive
or use of this additional step is only required  in  selected instances where the results of the
investigation are not conclusive.

7.1.5   Important Differences Between Workgroup Members as to Views/Observations

Workgroup members had a diversity of opinions over the benefits of a geometric mean-based as
opposed to AWQC based on SSM for certain water quality assessment and TMDL purposes.
Some preferred the use of a SSM-based standard, while others  preferred the use of a geometric
mean-based  standard.  One of the times of potential concern is when an individual  sample result
may be over the SSM but the data set does not exceed the geometric mean.  The concern is that
some event  may  have occurred during that time  and the public could potentially be at risk;
however, it is also possible that the result is a  one-time occurrence and the public is not at a
greater risk than at other locations that meet the geometric mean-based criteria.

7.2    Evaluation of Alternative Approaches for Criteria Development

This section describes the implementation considerations for each of the three alternative
approaches for the development of new or revised recreational water quality criteria that were
proposed and  discussed at  the workshop (see  Chapter 1).  Some of the concerns regarding
implementation that are common to all three approaches include the following:

    •   level of discriminatory power/sensitivity of a method;
    •   if rapid method is used, difficulty in implementation in some places (e.g., holding time);
       and
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    •   if site-specific epidemiological studies are needed,  most States will be unlikely to fund
       these studies.

Many of the above concerns, as well as the concerns described in the following sections, would
be eliminated if the following statements were true:

    •   epidemiological studies demonstrate that indicator  organisms are sufficiently correlated
       to human health risk;
    •   studies provide a scientific  basis for discounting  risk to human health  from wildlife
       sources of fecal contamination;
    •   criteria included flexibility to account for the reduced exposure (and thus,  lower risk) of
       use at extreme conditions (e.g., high flow);
    •   relationships between advisories and impairments  were more clearly defined in  EPA
       guidance;
    •   level of disinfection necessary to provide adequate pathogen  reduction/inactivation in
       human sewage was determined; and
    •   criteria applied for NPDES purposes included flexibility to account for wet weather
       conditions.

7.2.1   WHO Approach

The WHO approach provides a range of risk levels and accounts for differences in relative risk
resulting from site-specific considerations of sources of indicator organisms based on the results
of a sanitary inspection performed prior to the assessment  of monitoring results.  The following
implementation concerns are not specific to any  specific  application  of the WHO model, but
rather reflect the general use of this approach.

The WHO (2003) approach to criteria development relies  on identification of the potential for
human sources of fecal contamination to impact a beach or other recreational  water area. Many
pathogens are host-adapted and so human fecal sources may contain many pathogens not found
in feces from non-human  animals  (e.g.,  Salmonella typhi, Vibrio cholerae, Cryptosporidium
hominis,  Entamoeba,  many  viruses).    Thus,  it  is  essential to  have available  a reliable
methodology to distinguish between human and natural sources (e.g., wildlife only) of pathogens
for use of the WHO  model.   As part of this, the methodology should also be  able to either
quantify that the risk from natural sources is low  or provide some way to  characterize the risk
from natural sources as being acceptable.  It is important to  characterize or quantify the risk from
natural sources rather than to completely discount it because this risk needs to be included in
beach advisory decisions.  For example, if pathogens from  sea lions pose a  risk to humans, then
it is important to post an advisory on a beach where sea lions reside. However, it would not be
necessary  to  consider this risk in determining  impairment because sea lions are a "natural"
source and most environmental agencies would not view development of a plan to eliminate sea
lions as consistent with their overall mission.

It is also  important to be able to quantify the  risk from  domestic  animals  and  livestock and
include this risk if  a WHO-based  approach  is  pursued.  Although these  sources of  fecal
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contamination are nonhuman in nature, these animals live in close proximity to humans and may
carry human (zoonotic) pathogens in their feces(e.g., E. coli O157:H7, Cryptosporidiumparvum;
see also Strauch and Ballarini, 1994).   Use  of the WHO model will require including  the
likelihood of these sources impacting beaches and other recreational water  areas.  As a result, it
becomes important to quantify risks of exposure to fecal material of these animals.

The WHO approach  appears to  be amenable for use with multiple pathogen indicators  (e.g.,  the
toolbox). If multiple pathogen indicators are used in application of the WHO model, then all  the
considerations related to use of both molecular and culture methods that were discussed for each
CWA application above apply.  In addition, if multiple WHO model tables are used, it may be
advantageous to develop separate tables  for lakes and flowing waters because exposure in these
two situations are different.

There are several implementation issues that arise if the WHO  model is applied using a qPCR
analytical method. The first issue is the  capacity of States and NPDES dischargers to adopt and
use a qPCR method, as initially, there may be insufficient laboratory  capacity to conduct  the
method.  Specific concerns with respect to NPDES facilities  are discussed in the preceding
Section (7.12) on the NPDES permitting program.   Additionally, it is reasonable to  expect that
the initial costs per sample will  be substantially higher than for the currently used culture-based
methods, which poses an additional cost to States  and NPDES facilities.

The second implementation issue with respect to qPCR is its apparent inability to confirm that
disinfection is being properly applied.  As  discussed previously, NPDES permits need to both
assure that WQS are achieved and that State disinfection requirements are  being met.  If qPCR
method is used to apply the WHO approach, then another indicator using culture-based methods
will be needed in NPDES permits to demonstrate  adequate disinfection.

Another implementation issue is the use  of sanitary investigations based on the WHO approach.
However, the protocols for a sanitary investigation should not be overly prescriptive to the point
of making the investigation  resource-prohibitive.   There  is a need to  define the minimum
elements of a sanitary investigation to ensure that it is reliable.  Application of the criteria needs
to invoke trust by the public.   If there is too much variety in sanitary investigations, then  the
public will perceive that the investigations have no technical rigor and which will undermine  use
of the WHO model.  In addition, States will need to develop the capacity to conduct sanitary
investigations on every waterbody with  recreational uses, which constitutes a resource burden.
Finally, States need  sufficient time to conduct sanitary  investigations by  the time the new or
revised criteria are adopted into  their WQS.

The WHO approach  includes columns that  characterize different risk (see  Table 1, Chapter 1).
Two of the  columns include water characterizations  of "very  good" but are associated with
different risk.  The model should be applied with only one "acceptable risk" level.  If there is
more than one acceptable  category of good, it implies there is more than one "acceptable risk"
level. This makes it difficult to explain  to the public, difficult to enforce, and difficult to make
decisions on the lower risk level.  Any further distinction between "good" and  "very good"
outcomes should be voluntary.
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It is possible that States will issue advisories in situations that are not considered as  CWA
impairments. This can occur when a state public health agency wants to impose a higher degree
of protection than the state environmental agency, or at beaches where there are wildlife sources
that pose risk. It is uncertain how such a situation would work with the WHO model, and this
would need to be developed.

The WHO model uses ranges of pathogen densities.  This allows States to select which specific
value to use, and thus result in inconsistencies on thresholds to close or  open beaches between
various states. It is much more preferable for the criteria to specify one threshold rather than a
range. However,  it was discussed that while the range may be difficult to implement in a
regulatory fashion, it  may  more realistically describe the precision of  epidemiological-based
criteria applied to a wide range of waters coupled with the precision of indicator measurement.

Finally, it appears that empirical models of pathogen densities can be used with the WHO model,
as long as one threshold is used rather than a range.

7.2.2  EU Approach

The EU approach provides defined criteria at a single risk level but allows for adjustment of the
assessment result based on a sanitary investigation performed following review of monitoring
results.

Like  the WHO  (2003) approach,  the  EU  (EP/CEU, 2006) model  uses sanitary  inspections;
however, unlike the WHO approach, the EU model uses the inspections to rationalize that
monitoring results above the criteria levels do not indicate an elevated risk to human health.
Thus, the rigor of any type of sanitary investigation that may be required for an approach based
on the EU approach seems to be greater than for WHO-based approaches (i.e., requires a more
detailed site assessment).  A workgroup participant indicated that for some waters a desktop
GIS-based methodology could constitute a  sufficient sanitary survey for many bathing waters
(Paul Hunter, University of East Anglia, U.K., personal communication, 2007).

As  was the case  for the WHO model, there are implementation concerns regarding the time and
capacity for conducting sanitary investigations, and the ability to distinguish between risks from
human and nonhuman  sources of fecal contamination.  Specifically, States will need to know
how good are the techniques  to distinguish between risks from human and nonhuman sources,
and what is the degree of risk from nonhuman sources.   Thus,  the  discussion of the WHO
approach on these topics likewise applies to the EU approach.

As  one way to implement the  EU model, EPA could use a "pristine" watershed as a baseline.  In
this situation, EPA would look at pathogen indicator counts at baseline flows and use these
values to determine how to adjust concentrations.

The EU model process  presents opportunities to be more transparent to the public than the WHO
approach.  States could seek public involvement in  determining how to conduct the sanitary
investigation/discounting process.
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One impediment to implementation of the EU approach is how domestic and agricultural animals
are addressed. It appears that these sources can be excluded; however, these fecal contamination
sources may have a potential risk to human health.

The EU model characterizes beaches using the 95th percentile of a set of microbial water quality
data.  This seems to prevent making short-term decisions for beach closure or reopening unless
beach managers use some sort of predictive modeling.  This is an implementation concern given
the aforementioned (see Chapter 6) data needs of models.  Not all recreational water sites can
currently develop a model due to limited data.  If there is no model, then decisions would likely
be based on  a data set over a period of time, rather than a specific data point,  which would
require interpretation for beach monitoring for closing or opening decisions.

Like the WHO approach, the EU approach includes columns that characterize different risk (see
Table 2, Chapter 1). The model should be applied with only one "acceptable risk" level. If there
is more than one acceptable category of good, it implies there is more than one "acceptable risk"
level. This makes it difficult to explain to the public, difficult to enforce, and difficult to make
decisions on the lower risk level.  Any further distinction between "good"  and "very good"
outcomes will make implementation difficult in some jurisdictions.

7.2.3   Existing U.S. Model - 1986 Criteria

The existing model provides defined criteria at a single  risk level but does not provide for
adjustment based on  other  sources of information  such  as sanitary investigations or source
identification.

The original basis for the (EPA) 1986 criteria were freshwater and marine water epidemiological
studies conducted at a limited number of sites with restricted geographic extent and waterbody
type (lake beaches and marine beaches). Therefore, a concern exits that single value criteria may
not be applicable to all waters  across the United States—for instance, inland flowing waters,
tropical waters,  or freshwaters  under tidal influence.  In  the development of new or revised
criteria, epidemiological data or quantitative microbiological risk assessment (QMRA) for as
wide a variety of fresh and marine waters as is possible should be used.

If single value criteria are to be developed, as was the case  for the 1986 criteria, it is vital to use
as  many indicators as necessary to best characterize the microbiological quality of the water.
There is a variety of opinion as to the most appropriate indicators for fresh and marine waters.
However,  there is evidence  that E. coli is the most suitable indicator for flowing  freshwaters
while enterococci, either by culture- or molecular-based methods,  is most suitable for marine
waters; however, the workgroup did not reach a common opinion on the evidence.

A major criticism of the  1986 criteria was the lack  of approvable test methods for wastewater
effluent.  If new  indicator organisms or test methods are identified for the new criteria, approved
test methods must be developed for all potential needs such as NPDES  permitting and ambient
water quality monitoring.
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The 1986 criteria provide minimal implementation guidance.  Due to most States' interpretation
of the criteria in their WQS, the criteria tend to be treated as requiring compliance at all times
and in all waters.  This interpretation has caused considerable problems in the assessment and
TMDL arenas. Any new or revised criteria must include implementation guidance that allow for
methods to address issues such as extreme flows and nonhuman sources of fecal contamination.

EPA needs to provide  more scientific data  and  information to States for implementation  of
pathogen indicator criteria.  States have concerns regarding the effectiveness of existing sewage
treatment capabilities on new indicator organisms.  In switching from enterococci or E. coli as  an
indicator, there is concern that disinfection designs may not meet permit limits based on the new
indicator criteria. This issue needs to be addressed by EPA so that the State programs will  have
consistent, valid, and  scientifically defensible responses when these concerns are raised during
the implementation of new WQS.

7.2.4   Alternative Approaches

Two  additional potential  approaches to consider  in  the  development  of  new  or revised
recreational water quality criteria include the following:

1.   An alternative hybrid approach could blend the single value  criteria with facets of the WHO
    (2003) and  EU (EP/CEU, 2006) models  to allow for demonstration of mitigating (or
    discounting) factors to  be  completed by a fixed  date after  criteria adoption.  This has the
    advantage in preventing waters from being CWA §303(d)-listed based solely on excursions
    above a single value criteria.  If the water was ultimately listed, it could be de-listed at a later
    date if it were demonstrated that mitigating factors prevented designated use attainment.
2.   The largest implementation concern with the single value (EPA) 1986 criteria is regarding
    assessment.   An  alternative  approach to developing new criteria could incorporate the
    existing 1986 criteria with the following implementation provisions:
    •   a provision to  discount non-compliance  with  the single value criteria after investigation
       of the contributing watershed to confirm  the absence of nonhuman sources and lower risk
       than implied by the criteria exceedance;
    •   criteria/use inapplicability during extreme high flow events; and
    •   a process to exclude natural sources of fecal indicator organisms (i.e., indicators specific
       to human sources are not present),  according to the corresponding risk to human health.

7.3    Research Needs

Research is clearly needed to provide support for implementing any alternative approach  to
criteria development, expression, or application. A key concern is the role  research results play
in the ability of State and federal regulators to explain and gain public acceptance of changes in
existing CWA programs. Opportunities to leverage the value  of individual research programs  by
employing data collection designs that may be useful to answer multiple questions should  be
exploited.
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7.3.1   Near-term (Next 1 to 3 Years)

   Beach Monitoring

    1.  Provide a quantitative protocol  to  identify  the  types  of nonhuman sources of fecal
       contamination.   For example, other than molecular-based fecal  source identification
       techniques, are there methods (e.g.,  sanitary  investigations) to track nonhuman sources
       such as waterfowl, dogs, horses,  and other anthropogenic sources?   The WHO and EU
       approaches to criteria development  provide for "discounting" exceedances if it can be
       determined they  are of nonhuman origin through a sanitary inspection.  If risks from
       nonhuman sources can be adequately quantified, sanitary inspections could be used to
       support decision making.
   2.  Determine the risk  from different types  of nonhuman sources  of fecal contamination
       (e.g., domestic and  indigenous wildlife).   Although the new or revised criteria would
       need to address all potential risks, a delineation of the categories of risk made available to
       the  public would improve water quality  notification and informed consent  aspects of
       implementation.  Specifically, the perceived risk  associated by the public with elevated
       concentrations of indicators derived  from indigenous sources (e.g., deer, birds) may be
       more acceptable  than sources of  domestic origin  (e.g., cattle, poultry).  The public may
       wish to make an informed decision  about usage  relative to specific pathogens such as
       enterohemorrhagic E. coli (EHEC) that are potentially associated with agricultural land
       usage.
   3.  Determine under what conditions  a sanitary investigation would be sufficient (as opposed
       to microbial source tracking). This research is  most important if the WHO and EU
       approaches are being considered.
   4.  Identify minimum elements that a sanitary investigation should include.  Again, the focus
       should be on the  minimum elements  necessary for a reliable sanitary investigation. If the
       requirements for a sanitary investigation are too onerous, they will become resource-
       prohibitive and of minimal value. Assess the reliability, accuracy, and validity (etc.) of
       the  various types  of  sanitary  investigations.   Without some sort  of  standardized
       investigation criteria, inconsistencies will  result in the implementation of the criteria and
       create potential variances in health risk levels at beaches.
   5.  Predictive modeling offers the  prospect of benefits to beach management that are
       sufficiently significant such that it should be  explored further.  An identification of data
       needs is required for such models.  For water  quality notification purposes, models
       should be developed and calibrated to assure a minimum confidence level.

   NPDES

    1.  Conduct studies  to  develop a methodology to compare the correlation of the  culture-
       based methods and the qPCR (molecular-based) method. Identify how or where the same
       level of protection can be provided, even if implementation is different. Any requirement
       to  use non culture-based methods  may  have significant impacts  on  NPDES  permit
       monitoring programs. Non culture-based methods may not adequately assess treatment
       processes or determine permit compliance.
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    2.  Develop  an improved  understanding  of disinfection using  the  different indicators.
       Determine how well each indicator is in measuring disinfection effectiveness, including
       determination  of the viability of the organisms (pathogens  and indicators) following
       various disinfection processes (e.g., chlorination, UV light).
    3.  Determine risks of exposure from  intermittent microbial pollution discharges,  CSOs,
       urban runoff, and concentrated animal feeding operations (CAFOs).
    4.  Evaluate  the effectiveness and cost of stormwater and agricultural BMPs as related to
       pathogens and microbial contaminants.  This evaluation should be made in concert with
       epidemiological studies/QMRA analyses that will determine the risk from different types
       of sources (urban and agricultural runoff, indigenous and domestic animals, regrowth).
    5.  Evaluate  the efficacy, costs, and benefits of disinfection for the purposes of supporting
       eventual  promulgation  of a disinfection rule.  It is anticipated that disinfection could
       eventually be promulgated as a mandatory treatment technology nationwide  as it already
       is in many States.   Specifically, research is needed  to  support levels of disinfection
       necessary to provide adequate pathogen reduction/inactivation.

    Use Attainment

    1.  Research to determine  the  risk from  different types of nonhuman  sources of fecal
       contamination (e.g., domestic and indigenous) is needed to better quantify the risk from
       nonhuman sources  so that when implemented at recreational waters, those risks are better
       accounted for.
    2.  Develop  criteria or methodologies that more precisely define the health risk associated
       with pathogen exposure in recreational waters.

    Overall

    1.  Conduct research so that monitoring using  indicators can help to distinguish  human from
       nonhuman sources  of fecal contamination.
    2.  Conduct epidemiological/QMRA studies on flowing recreational waters.  Current (1986)
       criteria were based on epidemiological studies conducted in relatively static waterbodies.
       Additional studies  are needed to assess risks in flowing waters.  This has significant
       implications for criteria development for inland U.S. waterways.
    3.  Need  to  better understand the health-basis  for allowable  exceedance  frequency.
       Additional explanation is needed to justify percentile criteria differences between WHO,
       EU, and EPA (1986) criteria development approaches (e.g., use of 95th or 90th percentile).
    4.  Conduct  research  to better understand how to  measure the  impact  of regrowth  and
       persistence in  sediments of indicator bacteria on water quality.  The source of some
       problems of high pathogen  indicator levels may at times be due to regrowth rather than
       urban runoff, animals, birds, biofilms, ocean circulation, etc.

7.3.2   Long-term (Beyond 3 Years)

    NPDES
    •   Develop a viability assay for the viral and protozoan portion of effluent.
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    Overall
    •   Develop methodologies that are pathogen-specific.

References

EP/CEU (European Parliament/Council of the European Union). 2006. Directive 2006/7/EC of
the European Parliament and of the Council of 15 February 2006 Concerning the Management of
Bathing Water Quality and  Repealing Directive 76/160/EEC. Official Journal of the European
Union L64: 31-51. Available at:
http://europa.eu.int/eurlex/lex/LexUriServ/site/en/oj/2006/l_064/l_06420060304en00370051.pdf.

Strauch, D; Ballarini, G.  1994. Hygienic aspects of the production and agricultural use of animal
wastes. Journal of Veterinary medicine Series B 41: 176-228.

US EPA (U.S.  Environmental Protection Agency).  1986. Ambient Water Quality  Criteria for
Bacteria-1986. EPA440/5-84-002. Washington, DC: US EPA.

WHO  (World   Health   Organization).  2003.   Guidelines for   Safe  Recreational  Water
Environments. Volume 1  Coastal and Fresh Waters. Geneva, Switzerland: WHO.
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   APPENDIX A:  CHARGE TO THE EXPERT WORKGROUP MEMBERS


PURPOSE

The purpose of the Pellston-type1 Experts Scientific Workshop on Critical Research and Science
Needs for the Development of Recreational Water  Quality  Criteria is  for EPA to obtain
individual input from members of the broad scientific and technical community on the "critical
path" research and science needs for developing scientifically defensible new or revised Clean
Water Act (CWA) §304(a) recreational water quality criteria in the near-term.2

BACKGROUND

An important goal of the CWA is to protect and restore waters for swimming.  Section 304(a) of
the Act directs EPA to publish "advisory water quality guidance on the effects of the presence of
pollutants in water on health  and welfare."  These recommendations are referred to  as  §304(a)
criteria.  Under £304(a)(9)  of the CWA, EPA is required to publish water quality  criteria for
pathogens  and  pathogen indicators  to  protect  swimmers  from  illnesses   associated with
pathogenic microbes in coastal and Great Lakes waterbodies.

In  adopting new  or  revised water quality  standards, States must adopt  criteria  that  are
scientifically defensible and protective of the use, but they have flexibility to do so by  adopting
EPA's recommended  criteria, adopting  criteria to reflect site-specific conditions, or  adopting
other criteria  that are scientifically defensible.  In  the  case of criteria EPA publishes under
§304(a)(9),  States with coastal  and Great Lakes waters are required to adopt EPA's new or
revised criteria  for pathogens and pathogen  indicators into  State Water Quality Standards
(WQS).

Once adopted into State WQS, water quality criteria express the desired ambient condition of the
water to protect a designated use.  State WQS  are used for various CWA purposes or programs
that identify and address the sources of pollution with the goal of attainment of the  criteria,
including  National Pollutant Discharge Elimination System  (NPDES) permits, water  body
assessments to determine use attainment, and development of Total Maximum Daily Loads
(TMDLs).   In addition,  these WQS used by States in beach monitoring and water quality
notification programs.
    1  A workshop similar in organization and format to the Society of Environmental Toxicology and Chemistry
(SETAC) Pellston Workshops where technical experts in a particular subject area are invited to participate and
evaluate current and prospective environmental issues. A Pellston-type workshop brings together between 40 to 50
technical experts from academia, business, government, and public interest groups. Experts are sequestered for a
week and expected to contribute to a  summary report. Subject leaders are then responsible for consolidating,
editing, producing, and distributing the workshop proceedings.
    2  Near-term requirements: in order for EPA to develop criteria in the near-term, the indicators/methods/tools
upon which they are based must be currently available, have undergone scientific peer review and validation, and
ready for day-to-day implementation in State public health/environmental laboratories within the next 2 to 3 years.
New or revised criteria must be based on indicator/methods that are easy to use and interpret.
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Historically, EPA's recommended criteria for protecting people who recreate in water have been
based on fecal matter in recreational waters. In the 1960s, the federal government recommended
using the indicator bacteria, fecal coliforms, as the primary contact recreational3 criterion.  In the
late 1970s and early  1980s, EPA conducted public health studies evaluating several organisms as
possible indicators, including fecal coliforms, E. coli., and enterococci.  The studies showed that
enterococci are a good predictor of gastrointestinal (GI) illnesses in fresh and marine recreational
waters, and E. coli is a good predictor of GI illnesses in fresh waters.  As a result, EPA published
in 1986 revised criteria (EPA 's Ambient Water Quality Criteria for Bacteria - 19864) for primary
contact recreation recommending the use of E. coli for fresh recreational waters (criteria set as a
geometric mean of 126 colony forming units [cfu]/100 mL) and enterococci for fresh and marine
recreation waters (criteria set as geometric means of 33/100 mL  in freshwater and 35 cfu/100 mL
in marine water).  These recommendations replaced EPA's previously recommended bacteria
criteria for fecal coliforms of 200 cfu/100 mL.  EPA's criteria recommendations use "indicator"
bacteria.  Most strains of E. coli and all enterococci do not cause human illness (that is, they are
not human pathogens);  rather, they merely indicate  fecal contamination, and the assumption is
that pathogens co-occur with incidences of fecal contamination.

Since EPA issued its recreational criteria over 20 years ago, there have been significant scientific
advances, particularly in the areas of molecular biology, microbiology,  and analytical chemistry.
EPA  believes that these new scientific and technical  advances need to be  factored into the
development of new  or revised CWA §304(a) criteria for recreation.  To this end, EPA has been
conducting research  and assessing relevant scientific and technical information to provide the
scientific foundation for the development of new or revised  criteria.  The  enactment of the
Beaches Environmental Assessment and Coastal Health (BEACH) Act  of 2000 (which amended
the CWA) required EPA to conduct new studies and issue new or revised criteria, specifically for
Great Lakes and coastal marine waters.

OVERALL CHARGE TO THE EXPERTS

Experts are asked to provide their individual knowledge and insight that will help EPA define the
critical path research and science needs, recognizing the "state of the science" and the reality that
research that cannot be completed within 2 to 3 years  will not be helpful in EPA's near-term
criteria development efforts.  Experts should focus their efforts at this  Workshop on identifying
near-term research and  science needs that will allow EPA to publish new or revised criteria in
roughly 5 years.  (While  EPA understands that experts may wish  to offer perspectives on
research and  science  needs for the development of future or "next generation" criteria, this is not
the primary purpose of this Workshop.)  "Next generation" criteria refer to criteria EPA may
publish  in the  longer  term;  that is, in approximately  10 to  15  years,  pursuant to  CWA
§304(a)(9)(B).   Section 304(a)(9)(B)  directs EPA  to  review and,   as necessary, revise  the
§304(a)(9) criteria 5 years after EPA publishes the initial criteria, and every 5 years thereafter.)
    3 Primary contact recreation includes activities that could be expected to result in ingestion of water or
immersion. These activities include swimming, water skiing, surfing, and other activities  where contact and
immersion in water is likely.
    4 US EPA. 1986. Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002. Washington, DC: US
EPA.
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Although not the  focus  of this Workshop, EPA is aware  of stakeholder concerns regarding
implementation issues associated with the existing (EPA) 1986 criteria and the desire on the part
of some stakeholders for EPA to address these issues in the interim (i.e., before EPA publishes a
new or  revised recommended  criteria).   In recognition of these concerns, experts in the
"Implementation Realities" Workgroup are encouraged to identify aspects of the 1986 criteria
which  have been  cited as problematic, and, to the extent  that these  issues can be remedied
through  new  or revised criteria,  offer individual  input  for EPA to  consider  in  the  criteria
development efforts.5

The new or revised criteria must be scientifically sound, protective of the designated  use,
implementable for broad CWA purposes, and when implemented, provide for improved public
health  protection.  By  scientifically sound, EPA means that the  criteria  must be based on the
science and peer reviewed studies available at the time the criteria are developed. By protective
of the use EPA means that the criteria must establish the desired ambient condition of the water
to protect the designated use (e.g.,  primary contact recreation) given to the waterbody.  EPA's
new or revised criteria must also serve the broad purposes for which CWA criteria are intended,
including beach monitoring and water quality notification programs, development of water
quality based effluent  limits for National  Pollutant Discharge  Elimination  System (NPDES)
permits, waterbody assessments to determine use attainment,  and development of total maximum
daily loads  (TMDLs), where needed.  Lastly, the new or revised criteria, when implemented,
should also provide for improved public health protection and States must be satisfied that the
underlying science is sound and that the numeric  values of allowed  pollutant  in recreational
waters will achieve the desired environmental result.

On the last day of the Workshop, the chairs for the individual breakout topic groups will provide
EPA with sections of a draft Expert Report.   Each  of these  sections will summarize the
individual input provided by the experts  and collected by the Chairs throughout the  week's
discussions.  The Chairs will be asked to summarize commonalities and differences in the input
provided by participants, and  list  out the projects and  activities  that the individual  experts
identified as critical to the development of new or revised CWA §304(a) criteria in the near-term,
recognizing that research that cannot be completed in 2 to 3 years will not be useful in near-term
criteria development efforts.  (The workgroup  chairs may also summarize  any research and
science needs identified by the experts for developing "next generation" criteria.)

The draft Report will include a summary of expert views on the  following topics:  appropriate
pathogens or pathogen indicators, along with available  and  appropriate methods; single versus
"toolbox" criteria  approach; implementation issues; and most  importantly,  identification of
critical technical issues and uncertainties that could be addressed with near-term research.

EPA contractual  support will  be  available to the Chairs during  the  workshop to  provide
assistance in preparing the draft Report.  After the  workshop, EPA contractual support will be
available to the Chairs to  finalize their component of the Report in 1-month's time. EPA will use
    5 To the extent that experts come to some conclusion on how to better implement the 1986 criteria, EPA
intends to track these issues separately in order to not depart from the primary purpose of the meeting which is to
obtain input on critical research needs for the development of the near-term criteria.
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the Report as it develops a critical path science plan that will guide research activities over the
next 2 to 3 years.

Presented in the following  sections  of  this document  are  key questions on  seven major
overarching issues pertaining to criteria development and implementation.  A threshold issue that
impacts the deliberations of all groups is whether EPA should consider a fundamental change in
its approach to recommending recreational criteria; for example, switch from a single criterion in
all places to a diversified toolbox or tiered approach,  using multiple criteria, or several tools
supporting a single criterion, or some other combination.

Break-Out Group #1:  Approaches to Criteria Development (See Chapter I)6

Single versus  "Toolbox" Approach:   A  single criterion and/or method may  not adequately
address all CWA needs. One approach for new or revised criteria may consist of several "tools"
(i.e., indicators, methods, intrinsic geographic factors,  etc.) to fulfill all of the specific CWA
needs.  For example, it could involve  using molecular methods and rainfall models for beach
monitoring and water quality notification, and possibly  other method-indicator combinations for
other  CWA uses—provided that all criteria and methods are comparable in terms of level of
protection provided.  For example, the definition of an impaired recreational water in terms of
the number of people that would get sick when the water is not in compliance cannot differ from
the illness rate that triggers a beach advisory or closing.

The following set of questions is intended to guide a robust discussion among the experts in this
group.  The results  of this  discussion will improve the understanding  of the advantages and
disadvantages of various approaches to  criteria development.

    1.   What approaches exist currently for setting limits of pollutants that may be relevant for
       developing nationally recommended  recreational water  quality  criteria? Consider
       approaches used for other kinds of pollutants in water, in other  environmental media,
       and by other countries as well as approaches being implemented by States.  What are the
       pros and cons of each of these approaches?
    2.   Which of these approaches is most applicable and appropriate for developing nationally
       recommended recreational water quality criteria in the near-term?  Why is this approach
       on balance considered the most  applicable and appropriate?
    3.   For those  approaches identified as applicable and appropriate, what is the science that
       supports the approach? Is that science sufficient and of adequate quality?
    4.   Are there any critical research and science needs that should be addressed in developing
       or selecting an appropriate approach? Can this research be completed in time to be
       used in criteria development in the near-term?
    5.   Is a "toolbox" approach appropriate for developing new or revised recreational criteria
       in the near-term? Why or why not?
    6.   What are the pros and cons of selecting a "toolbox " approach?
    6 Because breakout group numbers do not correspond to chapter numbers in these proceedings, chapter
numbers are referred to for easier reference.


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    7.  What are desired features or characteristics that would make a "toolbox" approach
       appropriate?
    8.  Would a  "toolbox " approach achieve additional public health protection as compared to
       another approach?  Why or why not? If unknown,  what science  would need to be
       completed in order to determine whether a  "toolbox" approach would achieve additional
       public health protection?
    9.  Criteria for  secondary  contact  recreation could be part  of a  "toolbox."    What
       approaches  would be  appropriate  for  developing  criteria for  secondary  contact
       recreation?  Would this approach be different from that used to develop primary contact
       recreation criteria? Why and why not?
    10. What are critical research and science needs in developing or selecting an appropriate
       approach for secondary contact recreation? Can this research be completed in time to be
       used in criteria development in the near term?
    11. What are the implementation  considerations of the  different  approaches for  CWA
       purposes (1) beach monitoring and notification, (2) development of NPDES permits, (3)
       assessments to determine use attainment,  and (4) development of TMDLs?  Are  there
       practical considerations that could preclude, or greatly limit,  the use of an approach in
       routine, regulatory implementation (e.g., field sampling issues, laboratory challenges,
       staff training, etc.)?

Geographical Applicability:  Options for ensuring criteria are appropriate in a diverse range of
recreational waters include EPA recommending geographically different approaches, numbers,
or indicators, applicable to different regions (e.g., fresh and marine waters, coastal and inland
waters, tropical/subtropical and temperate waters) or types of waterbodies (e.g., lakes and
flowing waters).

    1.  Is a single criterion available  that is  applicable for  the diverse range of geographic
       conditions? Why or why not?
    2.  Is a "toolbox" approach appropriate for  different geographical conditions? Why and
       why not?
    3.  What would a  "toolbox " that addresses geographical differences look like ?
    4.  What are  critical research and science needs in developing or selecting an approach that
       will appropriately factor-in diverse geographical conditions?

Expression of Criteria:  EPA  is currently assessing  the degree  to which criteria should be
expressed as the mean concentration over a period of time (e.g., 30  days) and/or  as a daily or
instantaneous maximum value.

    1.  Given the diverse needs of the  CWA programs and the overarching goal of protecting
       and restoring waters for swimming, what protection is provided by establishing a 30-day
       "average " value as the  criteria?   What additional protection (if any) is provided by a
       daily or instantaneous maximum value?  From a scientific standpoint, is  one measure
       better scientifically than another for particular purposes (e.g., mean value for purposes
       of identifying impaired waters and daily maximum for beach monitoring and notification
       purposes)? Why?
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    2.  What  are pros and cons of expressing the criteria  differently for  the various CWA
      program needs?
    3.  What are the implications of instantaneous or daily values for public  health protection?
      If we don't currently have a good understanding of this, what are the critical research
      and science needs to answer these questions?
    4. If EPA were to set criteria at a mean concentration over 30 days and not recommend a
      single sample maximum, do we understand the illnesses that could occur on a single day
       (where the level would still lead to compliance with  the 30 day average)?
    5. If the science is not there, what are the critical research and science needs to answer this
      question?
    6.  What are the implementation considerations for CWA purposes of failing to address (and
      addressing) differences geographically  in  the  criteria  and failing to  include  (and
      including) a single sample maximum value for (1) beach monitoring and notification, (2)
      development of NPDES permits,  (3) assessments to determine use attainment, and (4)
      development of TMDLs?  Are there practical considerations that could preclude, or
      greatly limit, the usage in routine, regulatory implementation (e.g., field sampling issues,
      laboratory challenges, staff training, etc.)?

Break-Out Group #2:  Implementation Realities (See Chapter 7)

Although EPA wants the experts to consider implementation realities when providing input to all
general  and  specific questions throughout this  document, the following set of questions are
intended to guide a robust discussion among the experts about implementation issues and how
science and research could ease implementation.

    1.  What are the essential implementation considerations as EPA develops new nationally
      recommended  recreational  water  quality  criteria for  CWA  purposes:    (1)  beach
      monitoring and notification, (2)  development of NPDES permits, (3) assessments to
      determine use attainment, and (4)  development of TMDLs?
    2.  What are the major lessons learned in implementing the (EPA) 1986 criteria?  What
      worked well and not so well? How could we avoid repeating past "mistakes" that lead to
      delays in adoption or difficulties in implementing these  criteria?
    3.  Which  approaches to criteria development have the most  potential for success in
      implementation when  new  or  revised criteria  are adopted into State water  quality
      standards?  Why?
    4.  What are general features or characteristics that  would make new or revised criteria
      easy  to interpret and implement for states when adopted  into State water  quality
      standards?  Why?
    5.  Would a  "toolbox" approach be easier  or more difficult to  interpret and implement?
       What  are desirable characteristics  of a  "toolbox" criterion from an implementation
      perspective?
    6. If new  or revised criteria are provided as a range of values  instead of a single  value,
      what implementation concerns are triggered (e.g.,  can a range of values be used when
      developing NPDES permit limits or TMDL calculations)?
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    7.  What are critical path research and science needs that would enhance implementation of
       new or revised criteria in the near-term?

Break-Out Group #3:  Pathogens, Pathogen  Indicators,7 and Indicators of Fecal Contamination
(See Chapter 2)

Indicator Approach:   EPA previously  developed criteria based on indicators of the potential
presence of human pathogenic  organisms; that is, based on indicators of fecal contamination.
Other possible approaches such as pathogen index microorganisms and specific pathogens are
discussed below.

The following set of questions is intended to guide a robust discussion among the experts toward
the identification of critical research and science needs in the development of criteria based on
pathogens, pathogen indicators or indicators of fecal contamination. It is essential that this group
focus  discussions  on  only  those pathogens,  pathogen  indicators  or  indicators  of  fecal
contamination  where methods  are  ready now  for day-to-day  use in  State public health and
environmental  labs or where methods will be ready for day-to-day use in these labs within the
next 3 years.

A.   Fecal matter  indicators  (as surrogates for gastrointestinal and  non-gastrointestinal
diseases):
    1.  What are the benefits and shortcomings for continuing to implement  the current fecal
       indicators (E. coli and  enterococci)  to meet each of  the CWA §304(a) criteria  uses
       (beach  notification, TMDLs, NPDES permits, listing  of impaired waters)  to protect
       swimmers health from (a) gastrointestinal disease? (b) upper respiratory tract disease?
       (c) other diseases (skin,  ear, eye disease)? Should other CWA §304(a)  uses be tied to
       health outcomes?
    2.  Are there other microbial fecal indicator(s) that can be used to better meet each of the
       CWA  §304(a)  criteria uses and provide improved protection  against diseases  (e.g.,
       Bacteroides spp., Clostridium perfringens, coliphages or  otherphages)?  Why?
    3.  Are there  any  chemical biomarker fecal indicators  (e.g., fecal  stanols,  detergents,
       whiteners, caffeine) that can be used to better protect public health and meet all CWA
       purposes than the current indicators of fecal contamination?
    4.  What critical research would improve or widen the selection of fecal indicators available
       for the criteria?

B. Pathogens and their Index organisms (gastrointestinal and non-gastrointestinal disease):
    1.  Would a specific pathogen or index microorganism approach present an improvement in
       health protection over fecal indicators for each CWA use if applied as %304(a) criteria?
       If yes,  then  see question #2.   If no, what  research  could be  done to support this
    1 A specific pathogen belonging to a broader group of pathogens which would serve as a surrogate for the
presence and/or health risks for that group (e.g., Cryptosporidium serving as a surrogate for all parasitic protozoa);
or an indicator microorganism whose presence is correlated to the presence of a broad group of pathogens (e.g.,
spores of Clostridium perfringens serving as a surrogate for human or dog parasitic protozoa).
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       approach?  (also  for  skin,  upper  respiratory  tract,   ear,  eye  disease   criteria
       considerations)
    2.  What are the advantages and disadvantages of this approach?
    3.  What might be the most appropriate pathogens or index organisms? Why?
    4.  What data support a dose-response relationship  between a particular pathogen or its
       index in recreational water and any disease outcome?
    5.  The BEACH Act requires that EPA conduct research and develop new or revised water
       quality criteria for "Pathogens and Pathogen Indicators. "  The Act defines a pathogen
       indicator as a substance that indicates the potential for human infectious disease.  How
       might the term "index microorganism " relate to the statutory term pathogen indicator?
    6.  What is the  critical research  to make the selection  of pathogen/ index organisms
       available for the new or revised criteria and for the next generation criteria?

Application of Alternatives:  The following two  sections present some possible applications of a
mix of approaches that may increase the potential to improve monitoring, better express health
risks from swimming exposures,  and be more  comprehensive in their use to  meet all criteria
needs and provide more efficient and cost effective procedures.

C.  Application of fecal indicators, pathogen index organisms, and pathogens in combination for
criteria:
    1.  If none of the above three groups of surrogates can meet all CWA §304(a) criteria needs,
       is there any  combination of the three  that would provide  an acceptable  criteria
       approach?
    2.  What specific combined applications would have merit in meeting criteria needs?
    3.  Would the combined applications best utilize an analytical toolbox approach or a tiered
       analytical approach?
    4.  Would the criteria endpoint reflect a  general gastrointestinal disease target or a dose
       response estimate base on more limited disease symptoms reflecting the metrics used?
    5.  What research is important to make the  selection  of combinations available for the new
       or revised criteria and the next generation criteria?
    6.  Can adoption  of the  WHO/Annapolis Protocol approach8  that combines  sanitary
       reconnaissance  survey information  along  with microbial  assessment  to  develop
       surrogates of fecal contamination (predictive modeling) on the day to manage water
       advisories provide improved health gains over current criteria? Are  there sufficient
       examples of this approach to develop  new/improved use of indicators/surrogates in the
       near term?
    8 WHO (World Health Organization). 2003. Guidelines for Safe Recreational Water Environments. Volume 1
Coastal and Fresh Waters. Geneva, Switzerland: WHO.


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D. Applications  of all the above  for all categories of waters, climatology, and geographical
considerations:
    1.  Will the choices of individual, combined, or tiered fecal indicators, index organisms or
       pathogen indicators, or pathogens selected from above be capable of working for each or
       all of the following:
          a) Freshwaters (flowing and lakes/ponds) ?  Marine waters? POTWs? TMDLs?
          b)  Temper ate waters?  Tropical waters?
          c) High matrix waters (high in solids)? Special conditions?
    2.   What science or research is important in  the near term to make  the determination in
       Question Dl?

Break-Out Group #4: Methods Development (See Chapter 3)

The 1986 criteria are based on a culture method (EPA Method 1600) for the detection of fecal
indicators in ambient waters.  The Agency has been considering the use of newer methods, such
as qPCR and faster culture-based methods, for inclusion in new or revised  criteria.  EPA is
interested in input  on what other methods or  tools are available and should be considered for
developing criteria/standards that would meet all CWA purposes.

The following set of questions is intended to guide a robust discussion among the experts toward
the identification of critical research and science needs  in the development of detection methods
for the new criteria.   It is essential that this  group focus  discussions on those methods (and
pathogens, pathogen indicators or indicators of fecal contamination) that are ready now for day-
to-day use in State  public health and environmental labs or would be ready for day-to-day use in
these labs within the next 3 years.

    1.  Are there quantitative methods other than  membrane-filtration/Most Probable Number
       (MF/MPN)  methods that measure active organisms that EPA should consider for water
       quality criteria development?
    2.  Are there data to support other molecular methods for beach microbiological monitoring
       purposes?  Which molecular methods are most fully developed in your view ?
    3.  Are there data  to support other methods targeting non-microbiological surrogates of
       beach fecal pollution?  Which methods are most fully developed in your view?
    4.  How important is time-to-results in method selection from the perspective of public
       health protection ?
    5.  What further work needs to be done to ensure that the qPCR method or other promising
       (molecular) methods are considered valid for all CWA purposes?
    6.  What are the  pros and cons  of the use  of molecular methods in each of the CWA
       applications?
    7.  If some tools  are available for certain CWA uses only (e.g., for beach monitoring and
       notification) how could other methods be "linked" to the qPCR method so that they are
       scientifically sound and easily implementable? If only qPCR has been validated through
       epidemiological studies to predict health effects, what other studies  could be  done to link
       qPCR to other methods/indicators that may be more appropriate for §3 04 (a) uses?
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    8.  Depending on the method used, how could contamination at the beach be linked to all
       potential fecal sources of contamination? If the source  of the contamination was a
       treated point source, could the method be linked to the necessary source to address the
       contamination?
    9.  Current culture-dependent  methods  and qPCR  are  linked  to  health  risks  using
       epidemiological studies.  How would future methods (resulting from rapid technical
       advances)  be calibrated to health risks without new epidemiological studies?
    10. What  applications of water quality  criteria would  culture  methods, including  EPA
       Methods 1600 and 1603, be most suitable for and why?
    11. What further work needs  to be done to ensure that other culture methods are considered
       for CWA regulatory purposes? If the science is not  there, what are the critical path
       science or research needs to be used in this aspect of criteria development in the near-
       term?
    12. What new  methods and analytical technologies may be useful to begin to investigate in
       order for  these to potentially  be available in the  development of  "next generation"
       criteria (i.e., 10 or more years in the future)?
    13. Can other tools  (e.g., models, sanitary surveys) be developed to enhance the insight
       provided by water quality  indicators?
    14. What characteristics of analytical methods are essential for the methods used in both
       wastewater and ambient water?
    15. What are implementation considerations for  CWA purposes (1) beach monitoring and
       notification,  (2)  development of NPDES permits,  (3)  assessments  to  determine use
       attainment, and (4) development of TMDLs? Are  there practical considerations that
       could preclude,  or greatly limit, the usage in routine, regulatory implementation  (e.g.,
       field sampling issues, laboratory challenges, staff training, etc.)?

Break-Out Group #5: Comparing Risks (to  Humans) from Different Sources (See Chapter 4)

New or revised criteria should be  protective of waterborne  organisms that are  pathogenic to
humans whether the source is human waste or animal waste.  The following set of questions is
intended to guide a  robust discussion among the experts toward  the identification of critical
research and  science needs to better understand the relationship between the risks  posed by
exposure to human and animal wastes in recreational waters so that this may be considered in the
development of new criteria.

    1.  Is setting criteria based on a treated human point source such as a publicly (or privately)
       owned (sew age/wastewater)  treatment  work  (POTW) protective,  under-protective or
       overprotective of other potential sources of human pathogen?  Why or why not?  Are
       there data  to support this conclusion?
    2.  Based on the  "state of the science, " what conclusions or assumptions are reasonable to
       make about risks to humans exposed to human fecal contamination, non-point source
       contamination from animal sources, and mixed sources (e.g., combined sewer overflows
       and storm sewer overflows)?
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    3.  To what extent is it reasonable to apply risk estimates from POTW-influenced beaches to
       non-POTW beaches?  Do we  understand scientifically whether  this would lead to
       overprotection? What science would be important to understanding this?
    4.  Assess whether there  is a possibility of overprotection due to a compounding of risks
       from multiple factors (such as the current definition of GI illness [i.e., no fever]; more
       sensitive molecular methods; assuming that POTWrisks = non-human source risks, etc.)
    5.  How should EPA evaluate risk that  may have  a low probability of occurrence but  a
       significant risk, if it occurs?
    6.  What are the  key data gaps and uncertainties needed to support criteria development in
       the near term?

Break-Out Group #6: Acceptable Risk (See Chapter 5)

Population to be Protected:  EPA is currently reassessing the extent to which criteria protect
swimming populations, including some  vulnerable subpopulations (e.g., immunocompromised
individuals,  elderly, and children) against various types  of waterborne diseases (GI and non-GI)
caused by pathogens.

The following set of questions is intended to guide a robust discussion among the experts toward
the identification of critical research and science needs to better understand what protections new
criteria would provide and for what populations/subpopulations.

    1.  Is the science there now to understand the degree and extent of protection that nationally
       recommended criteria for  the  general population  would provide to  vulnerable
       subpopulations (e.g., immunocompromised individuals, elderly, and children)? Is the
       science there  now to understand whether nationally recommended criteria (based on the
       types of epidemiological studies EPA and others have  conducted to date) provide
       protection against all types of major waterborne diseases? If not, for which subgroups,
       pathogens, and waterborne illnesses is the science lacking?  What types of studies would
       be needed to answer these types of questions about the degree of public health protection
       provided by nationally recommended criteria?
    2.  What methodologies  or approaches for assessing human health risk or hazard should
       EPA consider as it develops new criteria? Why?
    3.  What are the  pros and cons of using GI illness  rates associated with differing levels of
       fecal contamination as the foundation for developing nationally recommended criteria?
    4.  Is there any scientifically-based reason to establish different "acceptable " risk levels for
       fresh water versus marine water?
    5.  Is the phrase  "acceptable risk" from the  (US EPA) 1986 criteria the best terminology or
       should we consider other terminology (e.g., tolerable or appropriate risk level)?
    6.  What science, if any, would be helpful to EPA in making decisions about what amount
       and type of human illness from recreation should be considered acceptable?
    7.  What is the level of human health protection provided by the implementation of the 1986
       criteria?  Is it really no more than 8 to 10 GI illnesses (with fever) per 1,000 in fresh
       water and 19 GI illnesses (with  fever) per 1,000 in marine waters,  or, are we really
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       protecting people from more than GI illness (with fever)?  What science is needed to
       under stand what protection is provided by the implementation of the 1986 criteria?

Protection of Humans from Drinking Water and Fish and Shellfish Consumption:  EPA is
currently assessing the degree to which recreational criteria can and should be developed to not
only protect people from illnesses associated with recreation, but also to protect people from
illness caused by drinking contaminated recreational water or consuming fish and shellfish found
in contaminated recreational water.

    1.  Will criteria that protect swimmers from swimming-related illnesses caused by pathogens
       also protect people who drink the water or eat fish or shellfish from the same water? Is
       the science sufficient to support a determination that recreational criteria will also
       protect drinking water uses and shellfish uses?
    2.  What additional science is needed to ensure that recreational criteria protect people
       from illnesses associated with recreation and also protect people from illnesses caused
       by drinking contaminated recreational water or consuming fish and shellfish found
       in contaminated recreational water?
    3.  Is the science there now to understand and characterize the degree ofprotectivenessfor
       all these elements?
    4.  If the science is not there, what are the critical path science or research needs to address
       this?

Break-Out Group #7:  Modeling Applications for Criteria Development and Implementation (See
Chapter 6)

Predictive modeling may  be useful as  a tool  to  help  with the development of site-specific
recreational water quality  criteria, and the implementation of criteria. Presently, EPA is not
considering models in its  plans  for new or revised criteria in the  near-term.  However, in
recognition that  some states and municipalities  currently  use models  effectively  in  beach
notification programs, EPA solicits input from experts regarding the potential use of models as
tools to aide implementation of the new or revised criteria, and further requests input on critical
research and science needs in this area for future  criteria development.

    1.  What  potential role  could  estimating  techniques  (or  models)  play  in  criteria
       development?  In the setting of site-specific criteria for recreational waters?
    2.  What potential role could  estimating techniques (or models) play  in implementing
       nationally recommended criteria for recreational waters?
    3.  What are advantages and disadvantages of using models, instead of direct measurement
       (monitoring), in water  quality management?  And  in particular,  in management of
       recreational waters?
    4.  What factors should be considered in  integrating modeling with current  monitoring
       regimes, or in changing monitoring regimes to include or support modeling?
    5.  What is the "state of the science " in modeling to support recreational water quality
       criteria development and implementation?
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    6.  What model evaluation procedures are used to insure the quality of predictive models for
       recreational water quality?
    7.  How does uncertainty in modeling compare to uncertainty in  monitoring?   How  can
       uncertainty be accurately represented and considered in risk analysis and public health
       decisions?
    8.  Do differences in the nature of the respective uncertainties inherent in modeling versus
       monitoring require different means of addressing these uncertainties?  For instance,
       issue an advisory on the basis of modeled results, but clear the advisory only on the basis
       of sampling.
    8.  What models would be most useful for certain "uses" of criteria (i.e., beach notification,
       assessment, permitting,   TMDLs)?   How  would modeling  be  used  together  with
       monitoring to cover all "uses " of criteria?
    9.  In models that are  currently being used to predict levels of indicator  bacteria, how are
       advisory/closure decisions being made  using model results, and how are the  results
       and/or the risk being communicated to the public?  Do paradigms currently exist  that
       would  be applicable  to  the communication  of modeled information on likely water
       quality?
    10. Given the differences between fresh water and marine  water environments in terms of
       physical predictive factors, what are the respective challenges  of the  two environments
       relative to developing predictive models?  What are the differences in data requirements,
       likely effectiveness  of models, and resources required to develop and implement useful
       models for the full range of intended purposes?
    11. What are the critical path  research and science needs EPA should pursue  to further
       enhance the capabilities and effectiveness of models in  the development/implementation
       of new or revised criteria? Why?
    12. What critical path research and science needs EPA should pursue to consider modeling
       in the development of next generation criteria?  Why?
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                     APPENDIX B:  PARTICIPANT LIST
Experts by Workgroup

Approaches to Criteria
Development	
Joel Hansel, Chair
Mark Gold
David Kay
John Ravenscroft
William Robertson
Jeffrey Seller
David Whiting

Pathogens, Pathogen Indicators, and
Indicators of Fecal Contamination
Nicholas Ashbolt, Chair
Roger Fuji oka
Toni Glymph
Charles McGee
Stephen Schaub
Mark Sobsey
Gary Toranzos

Comparing Risk (to Humans)
from Different Sources	
Dennis Juranek, Chair
Rebecca Calderon
Jack Colford
Elizabeth Doyle
Graham McBride
Samuel Myoda

Modeling Applications to Bacteria Criteria
Development and Implementation
Alexandria Boehm, Chair
Donna Francy
Mark Pfister
John Wathen
Richard Zepp
    Implementation Realities
    Lee Dunbar, Chair
    Thomas Atherholt
    Bart Bibler
    Lawrence Honeybourne
    Charles Noss
    James Pendergast
    Michael Tate
    Methods Development
    Stephen Weisberg, Chair
    Alfred Dufour
    Charles Hagedorn
    Sharon Kluender
    Erin Lipp
    Robin Oshiro
    Acceptable Risk
    Paul Hunter, Chair
    Michael Beach
    Lora Fleming
    Peter Teunis
    Timothy Wade
June 2007
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U.S. Environmental Protection Agency
                  Experts Scientific Workshop
Contact Information - Experts
(Alphabetical)

Nicholas Ashbolt (Chair)
USEPA
513-569-7303
Ashbolt.Nick@epa.gov

Thomas Atherholt
New Jersey Department of Environmental
Protection
609-984-2212
torn.atherholt@dep.state.nj .us

Michael Beach
Centers for Disease Control and
Prevention
770-488-7763
mjb3@cdc.gov

Bart Bibler
Florida Department of Health
850-245-4240
Bart_Bibler@doh.state.fi.us

Alexandria Boehm (Chair)
Stanford University, California
650-724-9128
ab oehm@ Stanford. edu

Rebecca L. C alder on
USEPA
919-966-0617
calderon.rebecca@epa.gov

Jack Colford
University of California, Berkeley
510-642-9370
j coiford@b erkel ey. edu

Elizabeth Doyle
USEPA
202-566-0056
doyle.elizabeth@epa.gov
  Alfred Dufour
  USEPA
  513-569-7330
  dufour.alfred@epa.gov

  Lee Dunbar (Chair)
  Connecticut Department of Environmental
  Protection
  860-424-3731
  lee.dunbar@po.state.ct.us

  Lora Fleming
  Departments of Epidemiology and Public
  Health and Marine Biology and Fisheries,
  University of Miami School of Medicine
  and Rosenstiel School of Marine and
  Atmospheric Sciences, Florida
  305-243-5912
  LFleming@med.miami.edu
  Donna Francy
  U.S. Geological Survey
  614-430-7769
  dsfrancy@usgs.gov

  Roger Fuji oka
  University of Hawaii, Manoa
  808-956-3096
  roger@hawaii. edu

  Mark Gold
  Heal the Bay, Santa Monica, California
  310-451-1500
  mgol d@Heal TheB ay. org

  Toni Glymph
  Wisconsin Department of Natural Resources
  608-264-8954
  Toni. Glymph@Wisconsin.gov
June 2007
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U.S. Environmental Protection Agency
                  Experts Scientific Workshop
Charles Hagedorn
Virginia Tech
540-231-4895
chagedor@vt.edu
Joel Hansel (Chair)
USEPA
404-562-9274
hansel.joel@epa.gov
Lawrence Honeybourne
Orange County Health Care Agency,
Santa Ana, California
714-433-6015
lhoneybourne@ochca.com

Paul Hunter (Chair)
University of East Anglia, U.K.
+ 44 1603 591004/593061
Paul.Hunter@uea.ac.uk

Dennis Juranek (Chair)
Centers for Disease Control and
Prevention (retired)
770-457-2056
ddjuranek@comcast.net

David Kay
University of Wales, U.K.
+44 1570423565
dvk@aber.ac.uk

Sharon Kluender
Wisconsin State Laboratory of Hygiene
608-224-6262
hesk@mail.slh.wisc.edu

Erin Lipp
University of Georgia
706-583-8138
elipp@uga.edu
   Graham McBride
   National Institute of Water and
   Atmospheric Research, New Zealand
   +64 7 8560726
   g.mcbride@niwa.co.nz

   Charles McGee
   Orange County Sanitation District,
   California
   714-593-7504
   CMCGEE@OCSD.COM

   Samuel Myoda
   Delaware Department of Natural Resources
   & Environmental Control
   302-739-9939
   Samuel.Myoda@state.de.us

   Charles Noss
   USEPA
   919-541-1322
   noss.charles@epa.gov

   Robin Oshiro
   USEPA
   202-566-1075
   oshiro.robin@epa.gov
  James Pendergast
  USEPA
  202-566-0398
  pendergast.jim@epa.gov

  Mark Pfister
  Lake County Health Department, Illinois
  847-377-8028
  MPfister@co.lake.il.us

  John Ravenscroft
  USEPA
  202-566-1101
  ravenscroft.j ohn@epa.gov
June 2007
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U.S. Environmental Protection Agency
                  Experts Scientific Workshop
William Robertson
Water, Air and Climate Change Bureau,
Health Canada
613-957-1505
Will_Robertson@hc-sc.gc.ca

Stephen Schaub
USEPA
202-566-1126
schaub. stephen@epa.gov

Mark Sobsey
University of North Carolina, Chapel Hill
919-966-7303
sobsey@email.unc.edu

Jeffrey Seller
Seller Environmental, Berkeley, California
510-847-0474
j soller@sollerenvironmental.com
Michael B. Tate
Kansas Department of Health and
Environment
785-296-5504
MTate@kdhe.state.ks.us

Peter Teunis
RIVM (National Institute of Public Health
and the Environment), Netherlands
+31 302742937
Peter.Teunis@rivm.nl
   Gary Toranzos
   University of Puerto Rico, Rio Piedras
   787-773-1743
   gatoranzos@uprrp. edu
   Timothy Wade
   USEPA
   919-966-8900
   wade.tim@epa.gov

   John Wathen
   USEPA
   202-566-0367
   wathen.j ohn@epa.gov

   Stephen Weisberg (Chair)
   Southern California Coastal Water Research
   Project
   714-755-3203
   stevew@sccwrp.org

   David Whiting
   Florida Department of Environmental
   Protection
   850-245-8191
   David.D.Whiting@dep.state.fl.us

   Richard Zepp
   USEPA
   706-355-8117
   zepp.richard@epa.gov
June 2007
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U.S. Environmental Protection Agency
                  Experts Scientific Workshop
Contact Information - EPA Resource
Personnel
(Alphabetical)

Shari Barash
202-566-0996
barash.shari@epa.gov

Samantha Fontenelle
202-566-2083
fontenelle. samantha@epa.gov

Patricia Harrigan
202-566-1666
harrigan.patricia@epa.gov

Rick Hoffmann
202-566-0388
hoffmann.rick@epa.gov

Denise Keehner (Workshop Chair)
202-566-1566
keehner. deni se@epa.gov
  Beth Leamond
  202-566-0444
  leamond.beth@epa.gov

  Kevin Oshima
  513-569-7476
  oshima.kevin@epa.gov

  Cynthia Roberts
  202-564-1999
  roberts.cindy@epa.gov

  Grace Robiou
  202-566-2975
  robiou.grace@epa.gov

  Lauren Wisniewski
  202-566-0394
  wisniewski.lauren@epa.gov
June 2007
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U.S. Environmental Protection Agency
                  Experts Scientific Workshop
Contact Information - Support Personnel
(Alphabetical)

Note Takers

Alexis Castrovinci
ICF International
703-934-3313
acastrovinci@icfi.com

Kristine Cornils (Implementation
Realities)
ICF International
(202)257-4591
kcornils@icfi.com

Mark Gibson
ICF International
703-934-3242
mgibson@icfi.com

Audrey Ichida
ICF International
703-934-3154
michida@icfi.com

Rebecca Kauffman
ICF International
781-676-4011
rkauffman@icfi. com

Joseph Keithley
ICF International
703-934-3438
jkeithley@icfi.com

Michelle Moser
ICF International
703-934-3887
mmoser@icfi.com
  Ami Parekh
  ICF International
  703-934-3173
  aparekh@icfi. com

  Laura Tuhela-Reuning
  ICF International
   (740)965-1999
  lmtuhela@owu.edu
  Kerry Williams
  ICF International
  703-218-2707
  kwilliams@icfi. com

  Facilitator

  Jan Connery
  ERG
  781-674-7322
  Jan.Connery@erg.com
  Logistics

  Patrick McCool
  GLEC
  231-941-2230
  pmccool@glec.com

  Peggy Himes
  GLEC
  231-941-2230
  phimes@glec. com

  Malkia Perry
  ERG
  703-633-1646
  Malkia.Perry@erg.com
June 2007
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      APPENDIX C: TRANSLATION OF EPIDEMIOLOGY TO DISEASE
                           BURDEN BY WHO AND EU

In a series of five international expert consultations that took place between 1996 to 2001, the
World Health Organization (WHO), together with partner organizations, including the EPA, the
Commission of the European Communities, and a group of independent experts, have developed
a  methodology for expressing  the  exposure-risk relationship  for recreational water.   This
approach is outlined in detail  in  Chapter  4  of the  WHO's (2003) Guidelines  for Safe
Recreational Water Environments. Volume 1 Coastal and Fresh Waters (see also Kay et al.,
2004). The broad framework is summarized below as a basis for burden of disease calculations.

Stated briefly, the approach is based on the following two assumptions:

    1.  that the statistical distribution of the fecal indicators (i.e., given a sufficiency of samples
       through  a  compliance  period  such  as  a bathing  season)  which  predict  illness in
       recreational waters is described by a logic-normal probability density function (pdf); and
    2.  that the pdf for any beach can be combined with the dose-response curve to produce a
       unique disease burden for a specific location.

Given a fixed  dose-response curve,  the relative disease burden (or proportion  of the exposed
population that becomes ill) for any beach, region or jurisdiction can be calculated from the
parameters  of the pdf, principally its geometric  mean (GM) value (i.e., the mean of the logio
transformed bacterial counts) and the standard deviation (SD) of the logio transformed bacterial
counts.  The mathematical basis of these calculations is outlined in WHO (2003), while Kay et
al. (2004) and Wyer et al. (1999) provide a discussion on the impacts of different GM and SD
assumptions.

Figure C-l  illustrates a theoretical pdf for any beach.  The cleaner the water, the further to the
left the peak of the pdf will be.  Figure C-2 provides the dose response curves reported in Kay et
al. (1994) that were used in deriving the standards in WHO (2003). Plot C-2a is projection of the
dose-response curve beyond the actual data range of >157 (intestinal) enterococci per 100 mL.
In fact, the projection of this relationship to exposures above  about 150 enterococci would not be
justified because the empirical data acquired during the U.K. randomized sea bathing trials was
restricted to lower exposures. Figure Plot C-2b assumes that the excess probability  of illness
does not continue to increase as enterococci exposure increases above the levels experienced in
the sea bathing trials.  This was chosen as the dose-response curve in the derivation of the 2003
WHO Guidelines as a pragmatic approach.  It should be recognized, however, that it may
represent an underestimate of the true disease burden if the curve does not,  in fact, flatten as
suggested in this diagram.
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                             30-,
                             25-
                          o
                          S  20H
                             15-
                                logio Mean = 1.176
                                    :SD = 0.751
                          (D
                          =J
                             10-

                              5-
                              0-
                               -2-101234
                                 log 10 faecal streptococci (cfu/100 ml)
                    Figure C-l.  A Probability Density Function of
                    Fecal  Indicator Distributions  Measured  at  a
                    Recreational  Water  Showing   Probability  of
                    Exposure   (Y   Axis)   versus   LoglO   Fecal
                    Streptococci    Concentration    (later    termed
                    enterococci).
                                 1.5
                                       2.0    2.5    3.0    3.5
                                     logio enterococci (per 100 ml)
                                                             4.0
                    Figure  C-2.   The  Dose-response Relationship
                    Derived From  Kay et al.  (1994) (a) and the
                    Functional Form Used to Derive the 2003 WHO
                    Guideline Values (b).  See Kay et al. (2004) for a
                    more detailed explanation.
June 2007
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U.S. Environmental Protection Agency
                                       Experts Scientific Workshop
Figure C-3  combines  the  pdf of Figure C-l with the dose-response  curve of Figure C-2 to
produce a relative disease burden prediction as a proportion of the exposed population.   The
mathematical basis of this process is provided in Kay et al. (2004).
                                 1012
                                    enterococci (per 100 ml)
-2
                              Probability density function

                              Proportion with illness

                    Mean = 0.9337 (geometric mean = 9 enterococci per 100 ml)
                    Standard Deviation = 0.8103
                    95th percentile = 2.2672 (185 enterococci per 100 ml)
                    Excess probability of illness = 0.05
                   ----  Dose response curve
              Figure C-3.  Combining the Dose-response Curve and the pdf
              to Produce  a Relative  Disease Burden  Assessment for  any
              Beach or Region.
June 2007
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The computation of gastrointestinal (GI) illness rates  in the population is accomplished  as
follows.  The pdf is described by:

                                        1    -(c-m)2
                                            e-
                                                Is2

Where c is the logio transformed enterococci concentration, y is the normal curve height, and m
is the mean enterococci concentration.  The associated probability of exposure across  a given
range of enterococci concentration (i.e., ca to c&,) for a given distribution is expressed by:

which is the area under the normal pdf curve between the limits ca and C},.  The proportion of
bathers with GI illness is then calculated from the area under the curve described by:
where/? is the probability of GI illness (gastroenteritis) from the dose-response relationship with
the upper limit set at 158 enterococci per 100 mL; that is:
                              p = 0.20102^-31.9)-2.3561

and z is the corresponding proportion of the normal curve height, y.  The associated probability
of GI illness  across the range of enterococci  concentrations, ca to c&,  is then expressed by the
following integral:
                                       0(c) = |
cb

  7- dc
For the WHO (2003) Guidelines derivation, the integration of these areas was performed using
iterative algorithms as outlined in Khabaza (1965).  The algorithm was checked against standard
tabulations of the normal pdf curve (Lindley and Miller, 1968) and an accuracy of at least four
significant figures was obtained over the specified range of the normal pdf.

References

Kay, D; Fleisher, JM; Salmon, RL; Jones, F; Wyer, MD; Godfree, AF; Zelenauch-Jacquotte, Z;
Shore, R. 1994. Predicting the likelihood  of gastroenteritis from  sea bathing - Results from
randomized exposure. The Lancet 344: 905-909.

Kay, D;  Bartram,  J;  Pruss, A;  Ashbolt, N; Wyer,  MD; Fleisher, JM; Fewtrell, L; Rogers, A;
Rees, G.  2004. Derivation of numerical values for the World Health Organization guidelines for
recreational waters. Water Research 38: 1296-1304.
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Khabaza, IM. 1965. Numerical Analysis. London: Pergam on Press.

Lindley,  DV; Miller,  JCP.  1968.  Cambridge Elementary Statistical  Tables.  Cambridge:
Cambridge University Press.

WHO  (World  Health  Organization).  2003.  Guidelines for  Safe  Recreational  Water
Environments. Volume 1 Coastal and Fresh Waters. Geneva,  Switzerland: WHO.

Wyer, D; Kay, D; Fleisher, JM. 1999.  An experimental health-related classification for marine
waters. Water Research 333: 715-722.
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       APPENDIX D: SUMMARY OF THE EUROPEAN COMMISSION
                                     DIRECTIVE


Revised Bathing Water Directive (EP/CEU, 2006)

The Directive sets out requirements for the following:

       (a) the monitoring and classification of bathing water quality;
       (b) the management of bathing water quality; and
       (c) the provision of information to the public on bathing water quality.

It is meant to apply to identified European Union (EU) bathing waters used by "large numbers"
of bathers which  must  be assessed against the criteria  in  Table 2 in Chapter  1  of these
proceedings (using the  previous  3 or  4 years of sampling data) though establishment of a
sampling program  to acquire  data from each bathing water at locations where a bathing water
"profile" suggests the greatest risk of pollution and/or the greatest numbers of bathers might be
expected (Article 3.3b).   Member States must monitor each bathing water in accordance with a
monitoring calendar established at the start of the bathing season  (Article 3.4). The monitoring
calendar can be suspended during "abnormal" conditions and samples taken during  "short term
pollution" may be disregarded (Article 3.6) provided that Member States comply  with the
additional provisions  outlined  below.

Bathing waters are legally required to achieve "sufficient"  microbiological status  by 2015
(Article 5.3), although the numerical values will be reviewed in 2008 (Article 14).

However,  bathing waters classified as "poor" in Table 2 may still remain in compliance with this
Directive  provided that Member States shall ensure that the following conditions are satisfied
(Article 5.4a(i-iv)):

       adequate management measures, including  a  bathing  prohibition or  advice  against
       bathing, with a view to preventing bathers' exposure to pollution and identification of the
       causes and reasons for the failure to achieve "sufficient" quality status is undertaken by
       Member States; and adequate measures to prevent, reduce  or eliminate the causes of
       pollution; and in accordance with Article 12, alerting the public by a clear and  simple
       warning sign and informing them of the causes of the pollution and measures taken, on
       the basis of the bathing water profile.

Member States must establish their bathing water profiles by  March 24, 2011, which will  be
reviewed as specified in Annex III of the Revised Bathing Water Directive.

Article  12 further  describes information which must be made available to the  public  at the
bathing water and communicated promptly by means of a sign, which includes:

       •  the current bathing water classification and any bathing prohibition or advice against
          bathing;
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       •  a general description of the bathing water, in non-technical language, based on the
          bathing water profile established in accordance with Annex III;
       •  in the  case of bathing waters subject to short-term pollution:  notification that the
          bathing water is subject to short-term pollution;
       •  an indication of the number of days on which bathing was  prohibited or advised
          against during the preceding bathing season because of such pollution, and a warning
          whenever such pollution is predicted or present;
       •  information on the nature and expected  duration of abnormal  situations during such
          events;
       •  whenever bathing is prohibited or advised against, a notice advising the public and
          giving reasons;
       •  whenever a permanent bathing prohibition or permanent  advice against bathing is
          introduced, the fact that the area concerned is no longer a bathing water and the
          reasons for its declassification; and
       •  an indication of sources of more complete information in accordance with paragraph
          2.

In addition, "Member States shall use appropriate media and technologies, including
the Internet, to disseminate actively and promptly the information concerning bathing
waters referred to in  paragraph  1 and also the following information in several
languages, when appropriate" (Article 12.1 and 12.2).

Where a bathing water  is subject to short-term pollution  the public  should also be informed on
the following (Article 12.4d):

       •  conditions likely to lead to short-term pollution;
       •  the likelihood of such pollution and its likely duration; and
       •  the causes of the pollution and  measures taken with a view to preventing bathers'
          exposure to pollution and to tackle its causes.

Member States are required to disseminate this knowledge using geo-referenced information and
signage at bathing waters beginning March 24, 2008.

Member States are free to simply use the numerical standards in Table 2.  However, they may
take advantage of the  opportunity to discount  samples  collected during short-term pollution
events provided  they  have  produced a  bathing water  profile  and  have complied with the
requirement to provide public information specified in Article 12, which requires real time water
quality prediction. No more than 15% of planned samples that are predicted to be of poor quality
(i.e., resulting in  public advisories) can be discounted in  this manner prior to the calculation  of
the compliance statistics.

References

EP/CEU (European Parliament/Council of the European  Union). 2006.  Directive 2006/7/EC  of
the European Parliament and of the Council  of 15 February 2006 Concerning the Management  of
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Bathing Water Quality and Repealing Directive 76/160/EEC. Official Journal of the European
Union L64: 31-51. Available at:   http://europa.eu.int/eur-lex/lex/LexUriServ/site/en/oj/2006/
I_064/l_06420060304en00370051 .pdf.
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                   APPENDIX E:  INDICATOR TERMINOLOGY
  Table E-l. Definitions for Indicator and Index Microorganisms of Public Health
  Concern.*

  Group	Definition	
  Indicator                    A group of organisms that demonstrates the efficacy of a
                              process, such as total heterotrophic bacteria or total coliforms
                              for chlorine disinfection
  Fecal indicator               A group of organisms that indicates the presence of fecal
                              contamination, such as the bacterial groups fecal coliforms or
                              E. co//'; thus, they only infer that pathogens may be present
  Index and model organisms   A group/or species indicative of pathogen presence and
                              behavior respectively, such as E. coli as an index for
                              Salmonella and F-RNA coliphages as models of human enteric
                              virus behavior in the environment
  Pathogen indicator           A specific pathogen belonging to a broader group of pathogens
                              which would serve as a surrogate for the presence and/or health
                              risks for that group (e.g., Cryptosporidium serving as a
                              surrogate for all parasitic protozoa), or an  indicator
                              microorganisms whose presence is correlated to the presence of
                              a broad group of pathogens (e.g., spores of Clostridium
                              perfringens  serving as a surrogate for human or dog parasitic
	protozoa)	
  *See Text Box E-l for definitions of microbial groups (adapted from Ashbolt et al, 2001).


             Text Box E-l.  Definitions of Key Fecal Indicator Microorganisms

Coliforms: Gram-negative, non spore-forming, oxidase-negative, rod-shaped facultative anaerobic
bacteria that ferment lactose (with p-galactosidase) to acid and gas within 24 to 48 hours at 36+2°C. Not
specific indicators of fecal pollution.

Fecal coliforms: coliforms that produce acid and gas from lactose at 44.5+ 0.2°C within 24+2 hours,
also known as thermotolerant coliforms due to their role as fecal indicators.

Escherichia coli (E. coli).  thermotolerant coliforms that produce indole from tryptophan, but also
defined now as coliforms able to produce p-glucuronidase (although taxqnomically up to 10% of
environmental E. coli may not). Most appropriate group of coliforms to indicate faecal pollution from
warm-blooded animals.

Fecal streptococci (FS): Gram-positive, catalase-negative cocci from selective media (e.g., azide
dextrose broth or m Enterococcus agar) that grow on bile aesculin agar and at 45°C, belonging to the
genera Enterococcus and Streptococcus possessing the  Lancefield group D antigen.

Enterococci: all fecal streptococci that grow at pH 9.6, between 10° and 45°C, and in 6.5% NaCl.
Nearly all are members of the genus Enterococcus, and also fulfil the following criteria: resistance to
60°C for 30 minutes and ability to reduce 0.1% methylene blue. The enterococci are a subset of fecal
streptococci that grow under the conditions outlined above.  Alternatively, enterococci can be directly
identified as micro-organisms capable of aerobic growth at 44±0.5°C and of hydrolysing 4-
methlumbelliferyl-B-D-glucoside (MUD, detecting p-glucosidase activity by blue florescence at 366nm),
in the presence of thallium acetate, nalidixic acid, and 2,3,5-triphenyltetrazolium chloride (TTC, which is
reduced to the red formazan) in the specified medium (ISO/FDIS  7899-1 1998).

Sulphite-reducing clostridia (SRC): Gram-positive, spore-forming, non-motile, strictly anaerobic rods
that reduce sulphite to H2S.	
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Clostridium perfringens. as for SRC, but also ferment lactose, sucrose and inositol with the production
of gas; produce a stormy clot fermentation with milk; reduce nitrate, hydrolyse gelatine, and produce
lecithinase and acid phosphatase. Bonde (1963) suggested that all SRC in receiving waters are not
indicators of fecal pollution; thus, C. perfringens is the appropriate indicator.

Bacteroidales: a family of strictly anaerobic bacteria present in the guts of warm-blooded animals. The
family to which Bacteroides belongs.

Bacteriodes.  Gram-negative, mainly  straight Bacteroides species that are: (a) obligately anaerobic, chain
saturated, anteiso-methyl, and iso-methyl branched acids, (b) saccharolytic, producing acetate and
succinate as the major metabolic end products; (c) contain enzymes of the hexose monophosphate shunt-
pentose phosphate pathway; (d) have a DNA-base composition in the range 40-48 mol% GC; (e)
membranes contain sphingolipids, and contain a mixture of long-chain fatty acids; (f) possess
menaquiones with MK-10 and MK-11 as the major components; and (g) contain raeso-diaminopimelic
acid in their peptidoglycan.  This definition restricts the Bacteroides to the following ten species:  B.
fragilis, B. thetaiotaomicron, B. vulgatus, B. ovatus, B. distasonis, B. uniformis, B. stercoris, B. eggerthii,
B. merdae, and B. caccae, with B. fragilis as the type  strain. The Bacteroides, along with Prevotella and
Porphyromonas, form one major subgroup in the bacterial phylum  Cytophaga-Flavobacter-Bacteroides.
This phylum diverged quite early in the evolutionary lineage of bacteria, and thus the Bacteroides,
although Gram-negative organisms, are not closely related to the enteric Gram-negatives such as
Escherichia coli.

Bacteriodes phages: Those viruses (bacteriophages) that use Bacteroides as a host for replication.
References


Ashbolt, NJ; Grabow, WOK; Snozzi, M. 2001. Indicators of Microbial Water Quality. Pp: 289-
316 in: Water Quality: Guidelines, Standards and Health Fewtrell, L; Bartram, J. (eds.). London:
IWA Publishing.
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 APPENDIX F:  SUMMARY OF MEASUREMENTS CURRENTLY PLANNED
         FOR THE DOHENY AND MALIBU BEACH (CALIFORNIA)
                          EPIDEMIOLOGY STUDY
  Table F-l. Summary of Measurements Currently Planned for the Doheny and Malibu
  Beach (California) Epidemiology Study.
         Indicator
          Method
       Investigator
 Traditional

   Enterococci
   Enterococci
   Fecal coliforms
   E. coli
   Total coliforms

 Rapid Traditional

   Enterococci
   Enterococci
   Enterococci
   Enterococci
   Enterococci
   E. coli
   E. coli
   E. coli

 Marker Genes
   Entero-Raptor, Esp gene
   Enterococci Esp gene
   E. coli virulence genes
   Bacteroides human marker
   Bacteroides human marker

 Phage
   Phage
   Phage
   Rapid phage

 Human Virus
   Adenovirus
IDEXX
Membrane-filtration (MF)
MF
MF or IDEXX
MF
Quantitative polymerase chain
reaction (qPCR)
qPCR
PCR-Luminex
Transcription-mediated
amplification/nucleic acid
sequence-based amplification
(TMA/NASBA)
Immunomagnetic separation (IMS)
qPCR
IMS
IMS
qPCR-Raptor
qPCR
qPCR
qPCR
qPCR
Culture
Culture
Antibodv
qPCR
South Orange County
Wastewater Authority (SOCWA)
SOCWA
SOCWA
Southern California Coastal
Water Research Project
(SCCWRP)
SOCWA
Noble
Stewart
Stewart
Moore
Bushon
Noble
Bushon
Jay
Harwood/Lim
Scott
Sadowsky
Field
Wuertz
Stewart
Sobsey
Sobsey
Sobsey
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Indicator
Enterovirus
Hepatitis A virus
Norovirus
Norovirus
Polyomavirus
Method
qPCR
qPCR
qPCR
qPCR
qPCR
Investigator
Stewart
Fuhrman
Stewart
Sobsey
Harwood
 Community Profiling
   Bacteroides
     thetaiotamicron          Sequencing
   Heliobacter pylori         Sequencing
   Campylobacter jejuni      Sequencing
   Clostridium perfringens    Sequencing
   Salmonella enteritica
     serovar Typhimurium     Sequencing
   Shigella dysenteriae        Sequencing
   Shigella flexneri           Sequencing
   Shigella boydii            Sequencing

 Bacterial Markers
   Bacteroides thetaiotamicron  qPCR
   Bacteroides thetaiotamicron  PCR
   Multiple methanogens        PCR
   Methanobrevibacter smithii   PCR-Luminex
   Methanobrevibacter smithii   qPCR
 	Legionella spp.	qPCR	
                 Moorthy
                 Moorthy
                 Moorthy
                 Moorthy

                 Moorthy
                 Moorthy
                 Moorthy
                 Moorthy
                Noble
                Leddy
                Ufhar
                Stewart
                Stewart
                Gast
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       APPENDIX G:  DEVELOPMENT OF DETERMINISTIC MODELS
The discussion of the  modeling workgroup members included the  present and future use of
statistically-based  models.   This relates to the fact that  they are currently being  used to
supplement monitoring information  and can be implemented in a resource-effective manner in
existing beach advisory programs.  In general, deterministic models  have not been included in
the main part of this discussion (see Chapter 6) because it was the common opinion of the
workgroup members of the modeling workgroup that their application represents a longer-range
measure that might be considered in the context of research  and development beyond the 2 to 3
year (near-term) window envisioned by the current criteria  development effort; however, there
were differences of opinion on the importance of this relative to development of new or revised
recreational water quality criteria.

Although not discussed in detail at this workshop, deterministic process-based models represent
an entire range of additional modeling tools that  could be used to inform water quality criteria
development  and implementation over the range of criteria framework  options that have been
discussed  during  the  course  of this  conference.    Applications of such models to beach
environments  are  discussed  in  the EPA  report Review  of Potential Modeling  Tools and
Approaches to Support the BEACH Program, (US EPA, 1999).  They range from those that are
simply based on precipitation to newer models  that consider other factors such as sediment
resuspension, hydrodynamics,  microbial growth  and  decay, and non-point source basin scale
inputs. For example, a process-based deterministic model has been recently used to predict fecal
indicator concentrations in coastal reaches  of southern Lake Michigan (Liu et al., 2006)  and
Huntington Beach, California (Boehm et al., 2005; Grant et al., 2005).  Deterministic models
also are being used in the development of total maximum daily loads (TMDLs) for pathogens
and in evaluations of non-point and sources of biological contaminants in watersheds.

In this  appendix,  deterministic  models for evaluating pathogens  in  watersheds  are  briefly
discussed. TMDLs often have to consider non-point sources from watersheds.  This discussion
is not intended to be comprehensive; rather, it is designed to illustrate  the range of tools available
to this area of consideration.

Commonly used TMDL models  allow users to discretize the watershed spatially and  bacteria
loads spatially and temporally, although this  capacity is limited.  As discussed in ASABE (2006),

       the models are also limited  in their ability to simulate  bacterial life cycles and bacteria
       concentrations.  Even with  their  limitations, these models are useful  when developing
       TMDLs if for no other reason than their use provides educational opportunities for both
       stakeholders and modelers throughout the TMDL process. The load duration method of
       developing TMDLs provides a good representation of overall water quality and needed
       water  quality improvement,  but intra-watershed  bacteria  contributions  must  be
       determined through supplemental sampling or through subsequent hydrologic and water
       quality modeling.   Identified  research  needs  include  improved  bacteria source
       characterization procedures and supporting data, and specific modeling advances.
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New models are now becoming available for evaluating non-point sources of pathogens derived
from watersheds and catchments.

    •   The L-THIA model (http://www.ecn.purdue.edu/run-off/lthianew/) combined with GIS-
       referenced inputs from Digital Watershed are being used as tools to evaluate runoff of
       fecal coliform and  fecal  streptococcus (enterococci) in watersheds.  Digital Watershed
       (http://www.iwr.msu.edu/dw/) allows the  user to view the watershed tributary  to any
       given point in the continental United States, on an 8-digit or (in parts of the Midwest) a
       12-digit HUC code level of detail.   L-THIA calculates the  surface and  groundwater
       impacts of current land use, land use changes and potential best  management practices
       (BMPs) for quality  and  quantity for the bacteria.   L-THIA will be directly linked to
       STORET water quality and SSURGO soils databases within a year. In the Midwest it is
       also available as a  web-based GIS  tool at the  12-digit HUC code level through  the
       watershed delineation tool at http://pasture.ecn.purdue.edu/~watergen/.
    •   The SPARROW model  (SPAtially  Referenced Regression on  Watershed attributes)
       (http://water.usgs.gov/nawqa/sparrow/index.html) is being used to  investigate the sources
       and fate of fecal contamination in  streams  and to assess  the  effects  of the  spatial
       resolution  of the  stream network  and  landscape data on  model  parameters and
       predictions.  SPARROW has been  used to  evaluate the following indicators:  fecal
       coliforms, E. coli, C. perfringens, somatic coliphage, F+ RNA phage, and the bacterial
       pathogen Campylobacter.  The explanatory data for the SPARROW models include land
       use and other data that describe the climatic, hydrologic,  and physical conditions of the
       catchments. The models also reveal the effects of climate, soils, and instream processes
       on the transport of fecal contaminants.
    •   LSPC is the Loading Simulation Program in C++, a watershed  modeling  system that
       includes streamlined Hydrologic Simulation  Program  Fortran (HSPF) algorithms  for
       simulating hydrology, sediment, and general water quality on land as well as a simplified
       stream  transport  model.   LSPC has been used  in  Alabama  for developing pathogen
       TMDLs    (see     http://www.epa.gov/athens/wwqtsc/Toolbox-overview.pdf    and
       http ://www. epa. gov/ATHENS/wwqtsc/html/1 spc. html).

In addition to these models, a 1999 EPA report describes other potential models that can be used
for evaluating non-point sources of biological contaminants from catchments. These include, for
example, HSPF. HSPF is one of the models that is included in the BASINS3 watershed model
system that is maintained by EPA (http://www.epa.gov/waterscience/BASINS/).

References

ASABE (American Society of Agricultural and Biological Engineers).  2006. Modeling bacteria
fate and transport in watersheds to support  TMDLs.  Proceedings  from the ASAE  Annual
Meeting. Paper 062295.

Boehm, AB; Keymer,  DP; Shellenbarger,  GG. 2005. An analytical  model of enterococci
inactivation, grazing, and transport in the surf zone of a  marine beach. Water Research 39(15):
3565-3578.
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Grant,  SB; Kim, JH; Jones,  BH;  Jenkins, SA;  Wasyl, J;  Cudaback, C. 2005.  Surf  zone
entrainment, along-shore transport, and human health implications of pollution from tidal outlets.
Journal of Geophysical Research 110: C10025.

Liu, L; Phanikumar, M; Molloy, S; Whitman, RL; Shively, D; Nevers, D; Schwab, D; Rose, J.
2006. Modeling the transport and inactivation of E. coli and enterococci in the near-shore region
of Lake Michigan. Environmental Science and Technology 40(16): 5022-5028.

US EPA (U.S. Environmental Protection Agency). 1999. Review of Potential Modeling Tools
and Approaches to Support the BEACH Program. EPA-823-R-99-002.  Washington, DC: US
EPA.
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